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1 <?xml version="1.0" encoding="ISO-8859-1"?>
2 <?xml-stylesheet type="text/xsl" href="jvmti.xsl"?>
3 <!--
4 Copyright 2002-2006 Sun Microsystems, Inc. All Rights Reserved.
5 DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
6
7 This code is free software; you can redistribute it and/or modify it
8 under the terms of the GNU General Public License version 2 only, as
9 published by the Free Software Foundation.
10
11 This code is distributed in the hope that it will be useful, but WITHOUT
12 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 version 2 for more details (a copy is included in the LICENSE file that
15 accompanied this code).
16
17 You should have received a copy of the GNU General Public License version
18 2 along with this work; if not, write to the Free Software Foundation,
19 Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20
21 Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
22 CA 95054 USA or visit www.sun.com if you need additional information or
23 have any questions.
24
25 -->
26
27 <!DOCTYPE specification [
28 <!ELEMENT specification (title, intro*, functionsection, errorsection,
29 eventsection, datasection, issuessection, changehistory)>
30 <!ATTLIST specification label CDATA #REQUIRED
31 majorversion CDATA #REQUIRED
32 minorversion CDATA #REQUIRED
33 microversion CDATA #REQUIRED>
34
35 <!ELEMENT title (#PCDATA|jvmti|tm)*>
36 <!ATTLIST title subtitle CDATA #REQUIRED>
37
38 <!ELEMENT intro ANY>
39 <!ATTLIST intro id CDATA #IMPLIED
40 label CDATA "">
41
42 <!ELEMENT functionsection (intro*, category*)>
43 <!ATTLIST functionsection label CDATA #REQUIRED>
44
45 <!ELEMENT category ((intro|typedef|uniontypedef|capabilitiestypedef)*,
46 (function|callback|elide)*)>
47 <!ATTLIST category id CDATA #REQUIRED
48 label CDATA #REQUIRED>
49
50 <!ELEMENT function (synopsis, typedef*, description?, origin,
51 (capabilities|eventcapabilities),
52 parameters, errors)>
53 <!ATTLIST function id CDATA #REQUIRED
54 num CDATA #REQUIRED
55 phase (onload|onloadOnly|start|live|any) #IMPLIED
56 callbacksafe (safe|unsafe) #IMPLIED
57 impl CDATA #IMPLIED
58 hide CDATA #IMPLIED
59 jkernel (yes|no) #IMPLIED
60 since CDATA "1.0">
61
62 <!ELEMENT callback ((jmethodID|jfieldID|jframeID|jrawMonitorID|jclass|jthread|jthreadGroup|jobject|
63 jvalue|enum|jint|jlong|jfloat|jdouble|jlocation|jboolean|char|uchar|size_t|void),
64 synopsis, description?, parameters)>
65 <!ATTLIST callback id CDATA #REQUIRED
66 since CDATA "1.0">
67
68 <!ELEMENT synopsis (#PCDATA|jvmti)*>
69
70 <!ELEMENT typedef (description?, field*)>
71 <!ATTLIST typedef id CDATA #REQUIRED
72 label CDATA #REQUIRED
73 since CDATA "1.0">
74
75 <!ELEMENT uniontypedef (description?, field*)>
76 <!ATTLIST uniontypedef id CDATA #REQUIRED
77 label CDATA #REQUIRED
78 since CDATA "1.0">
79
80 <!ELEMENT field ((jmethodID|jfieldID|jframeID|jrawMonitorID|jclass|jthread|jthreadGroup|jobject|
81 jvalue|enum|jint|jlong|jfloat|jdouble|jlocation|jboolean|char|uchar|size_t|void|allocfieldbuf|inptr|inbuf|outbuf|vmbuf|ptrtype|struct),
82 description)>
83 <!ATTLIST field id CDATA #REQUIRED>
84
85 <!ELEMENT capabilitiestypedef (description?, capabilityfield*)>
86 <!ATTLIST capabilitiestypedef id CDATA #REQUIRED
87 label CDATA #REQUIRED>
88
89 <!ELEMENT capabilityfield (description)>
90 <!ATTLIST capabilityfield id CDATA #REQUIRED
91 disp1 CDATA ""
92 disp2 CDATA ""
93 since CDATA "1.0">
94
95 <!ELEMENT description ANY>
96
97 <!ELEMENT capabilities (required*, capability*)>
98
99 <!ELEMENT eventcapabilities EMPTY>
100
101 <!ELEMENT required ANY>
102 <!ATTLIST required id CDATA #REQUIRED>
103
104 <!ELEMENT capability ANY>
105 <!ATTLIST capability id CDATA #REQUIRED>
106
107 <!ELEMENT parameters (param*)>
108
109 <!ELEMENT param ((jmethodID|jfieldID|jframeID|jrawMonitorID|jclass|jthread|jthreadGroup|jobject|
110 jvalue|enum|jint|jlong|jfloat|jdouble|jlocation|jboolean|char|uchar|size_t|void|varargs|struct|ptrtype|
111 outptr|allocbuf|allocallocbuf|inptr|inbuf|outbuf|vmbuf|agentbuf),
112 description)>
113 <!ATTLIST param id CDATA #REQUIRED>
114
115 <!ELEMENT jmethodID EMPTY>
116 <!ATTLIST jmethodID class CDATA #IMPLIED
117 native CDATA #IMPLIED>
118
119 <!ELEMENT jfieldID EMPTY>
120 <!ATTLIST jfieldID class CDATA #IMPLIED>
121
122 <!ELEMENT jclass EMPTY>
123 <!ATTLIST jclass method CDATA #IMPLIED
124 field CDATA #IMPLIED>
125
126 <!ELEMENT jframeID EMPTY>
127 <!ATTLIST jframeID thread CDATA #IMPLIED>
128
129 <!ELEMENT jrawMonitorID EMPTY>
130
131 <!ELEMENT jthread EMPTY>
132 <!ATTLIST jthread started CDATA #IMPLIED
133 null CDATA #IMPLIED
134 frame CDATA #IMPLIED
135 impl CDATA #IMPLIED>
136
137 <!ELEMENT varargs EMPTY>
138
139 <!ELEMENT jthreadGroup EMPTY>
140 <!ELEMENT jobject EMPTY>
141 <!ELEMENT jvalue EMPTY>
142 <!ELEMENT jchar EMPTY>
143 <!ELEMENT jint EMPTY>
144 <!ATTLIST jint min CDATA #IMPLIED>
145 <!ELEMENT jlong EMPTY>
146 <!ELEMENT jfloat EMPTY>
147 <!ELEMENT jdouble EMPTY>
148 <!ELEMENT jlocation EMPTY>
149 <!ELEMENT jboolean EMPTY>
150 <!ELEMENT char EMPTY>
151 <!ELEMENT uchar EMPTY>
152 <!ELEMENT size_t EMPTY>
153 <!ELEMENT void EMPTY>
154 <!ELEMENT enum (#PCDATA)*>
155 <!ELEMENT struct (#PCDATA)*>
156
157 <!ELEMENT nullok ANY>
158
159 <!ELEMENT ptrtype ((struct|jmethodID|jfieldID|jframeID|jrawMonitorID|jclass|jthread|
160 jthreadGroup|jobject|jvalue), nullok?)>
161
162 <!ELEMENT outptr ((struct|jmethodID|jfieldID|jframeID|jrawMonitorID|jclass|jthread|
163 jthreadGroup|jobject|jvalue|enum|jchar|jint|jlong|jfloat|jdouble|
164 jlocation|jboolean|char|uchar|size_t|void), nullok?)>
165
166 <!ELEMENT allocbuf ((struct|jmethodID|jfieldID|jframeID|jrawMonitorID|jclass|jthread|
167 jthreadGroup|jobject|jvalue|enum|jint|jlong|jfloat|jdouble|
168 jlocation|jboolean|char|uchar|size_t|void), nullok?)>
169 <!ATTLIST allocbuf incount CDATA #IMPLIED
170 outcount CDATA #IMPLIED>
171
172 <!ELEMENT allocallocbuf ((struct|jmethodID|jfieldID|jframeID|jrawMonitorID|jclass|jthread|
173 jthreadGroup|jobject|jvalue|enum|jint|jlong|jfloat|jdouble|
174 jlocation|jboolean|char|uchar|size_t|void), nullok?)>
175 <!ATTLIST allocallocbuf incount CDATA #IMPLIED
176 outcount CDATA #IMPLIED>
177
178 <!ELEMENT inptr (struct, nullok?)>
179
180 <!ELEMENT inbuf ((struct|jmethodID|jfieldID|jframeID|jrawMonitorID|jclass|jthread|
181 jthreadGroup|jobject|jvalue|enum|jint|jlong|jfloat|jdouble|
182 jlocation|jboolean|char|uchar|size_t|void), nullok?)>
183 <!ATTLIST inbuf incount CDATA #IMPLIED>
184
185 <!ELEMENT outbuf ((struct|jmethodID|jfieldID|jframeID|jrawMonitorID|jclass|jthread|
186 jthreadGroup|jobject|jvalue|enum|jint|jlong|jfloat|jdouble|
187 jlocation|jboolean|char|uchar|size_t|void|outbuf), nullok?)>
188 <!ATTLIST outbuf incount CDATA #IMPLIED
189 outcount CDATA #IMPLIED>
190
191 <!ELEMENT vmbuf ((struct|jmethodID|jfieldID|jframeID|jrawMonitorID|jclass|jthread|
192 jthreadGroup|jobject|jvalue|enum|jchar|jint|jlong|jfloat|jdouble|
193 jlocation|jboolean|char|uchar|size_t|void), nullok?)>
194 <!ATTLIST vmbuf incount CDATA #IMPLIED
195 outcount CDATA #IMPLIED>
196
197 <!ELEMENT agentbuf ((struct|jmethodID|jfieldID|jframeID|jrawMonitorID|jclass|jthread|
198 jthreadGroup|jobject|jvalue|enum|jint|jlong|jfloat|jdouble|
199 jlocation|jboolean|char|uchar|size_t|void), nullok?)>
200 <!ATTLIST agentbuf incount CDATA #IMPLIED
201 outcount CDATA #IMPLIED>
202
203 <!ELEMENT allocfieldbuf ((struct|jmethodID|jfieldID|jframeID|jrawMonitorID|jclass|jthread|
204 jthreadGroup|jobject|jvalue|enum|jint|jlong|jfloat|jdouble|
205 jlocation|jboolean|char|uchar|size_t|void))>
206 <!ATTLIST allocfieldbuf outcount CDATA #IMPLIED>
207
208 <!ELEMENT errors (error*)>
209
210 <!ELEMENT error ANY>
211 <!ATTLIST error id CDATA #REQUIRED>
212
213 <!ELEMENT errorsection (intro*, errorcategory*)>
214 <!ATTLIST errorsection label CDATA #REQUIRED>
215
216 <!ELEMENT errorcategory (intro*, errorid*)>
217 <!ATTLIST errorcategory id CDATA #REQUIRED
218 label CDATA #REQUIRED>
219
220 <!ELEMENT errorid ANY>
221 <!ATTLIST errorid id CDATA #REQUIRED
222 num CDATA #REQUIRED>
223
224 <!ELEMENT datasection (intro*, basetypes*)>
225
226 <!ELEMENT basetypes (intro*, basetype*)>
227 <!ATTLIST basetypes id CDATA #REQUIRED
228 label CDATA #REQUIRED>
229
230 <!ELEMENT basetype (definition?,description)>
231 <!ATTLIST basetype id CDATA #REQUIRED>
232
233 <!ELEMENT definition (#PCDATA|jvmti)*>
234
235 <!ELEMENT eventsection (intro*, (event|elide)*)>
236 <!ATTLIST eventsection label CDATA #REQUIRED>
237
238 <!ELEMENT event (description, origin, typedef*, capabilities, parameters)>
239 <!ATTLIST event id CDATA #REQUIRED
240 label CDATA #REQUIRED
241 const CDATA #REQUIRED
242 num CDATA #REQUIRED
243 phase (onload|start|live|any) #IMPLIED
244 filtered (thread|global) #IMPLIED
245 since CDATA "1.0">
246
247 <!ELEMENT issuessection (intro*)>
248 <!ATTLIST issuessection label CDATA #REQUIRED>
249
250 <!ELEMENT changehistory (intro*, change*)>
251 <!ATTLIST changehistory update CDATA #REQUIRED
252 id CDATA #REQUIRED>
253
254 <!ELEMENT change ANY>
255 <!ATTLIST change date CDATA #REQUIRED
256 version CDATA #IMPLIED>
257
258 <!ELEMENT functionlink (#PCDATA|jvmti|code|i|b)*>
259 <!ATTLIST functionlink id CDATA #REQUIRED>
260
261 <!ELEMENT datalink (#PCDATA|jvmti|code|i|b)*>
262 <!ATTLIST datalink id CDATA #REQUIRED>
263
264 <!ELEMENT typelink (#PCDATA|jvmti|code|i|b)*>
265 <!ATTLIST typelink id CDATA #REQUIRED>
266
267 <!ELEMENT fieldlink (#PCDATA|jvmti|code|i|b)*>
268 <!ATTLIST fieldlink id CDATA #REQUIRED
269 struct CDATA #REQUIRED>
270
271 <!ELEMENT paramlink (#PCDATA|jvmti|code|i|b)*>
272 <!ATTLIST paramlink id CDATA #REQUIRED>
273
274 <!ELEMENT eventlink (#PCDATA|jvmti|code|i|b)*>
275 <!ATTLIST eventlink id CDATA #REQUIRED>
276
277 <!ELEMENT errorlink (#PCDATA|jvmti|code|i|b|tm)*>
278 <!ATTLIST errorlink id CDATA #REQUIRED>
279
280 <!ELEMENT externallink (#PCDATA|jvmti|code|i|b|tm)*>
281 <!ATTLIST externallink id CDATA #REQUIRED>
282
283 <!ELEMENT vmspeclink EMPTY>
284 <!ATTLIST vmspeclink id CDATA #IMPLIED>
285 <!ATTLIST vmspeclink name CDATA #IMPLIED>
286 <!ATTLIST vmspeclink preposition CDATA #IMPLIED>
287
288 <!ELEMENT internallink (#PCDATA|jvmti|code|i|b)*>
289 <!ATTLIST internallink id CDATA #REQUIRED>
290
291 <!ELEMENT functionphaselist EMPTY>
292 <!ATTLIST functionphaselist phase (onload|onloadOnly|start|live|any) #REQUIRED>
293
294 <!ELEMENT eventphaselist EMPTY>
295 <!ATTLIST eventphaselist phase (onload|start|live|any) #REQUIRED>
296
297 <!ELEMENT issue ANY>
298
299 <!ELEMENT rationale ANY>
300
301 <!ELEMENT todo ANY>
302
303 <!ELEMENT origin (#PCDATA)*>
304
305 <!ELEMENT elide (intro|function|callback|event)*>
306 <!ATTLIST elide why CDATA #IMPLIED>
307
308 <!ELEMENT constants (constant*)>
309 <!ATTLIST constants id CDATA #REQUIRED
310 label CDATA #REQUIRED
311 kind (enum|bits|const) #REQUIRED
312 since CDATA "1.0">
313
314 <!ELEMENT constant ANY>
315 <!ATTLIST constant id CDATA #REQUIRED
316 num CDATA #REQUIRED>
317
318 <!ELEMENT tm (#PCDATA)>
319
320 <!ELEMENT i (#PCDATA|jvmti|tm)*>
321
322 <!ELEMENT b (#PCDATA|jvmti|code)*>
323
324 <!ELEMENT code (#PCDATA|space)*>
325
326 <!ELEMENT pre ANY>
327
328 <!ELEMENT space EMPTY>
329
330 <!ELEMENT jvmti EMPTY>
331
332 <!ELEMENT example (#PCDATA|i)*>
333
334 <!ELEMENT br EMPTY>
335
336 <!ELEMENT p EMPTY>
337
338 <!ELEMENT dl (dt|dd)+>
339
340 <!ELEMENT dd ANY>
341
342 <!ELEMENT dt (#PCDATA|jvmti|code|i|b)*>
343
344 <!ELEMENT table (tr)+>
345
346 <!ELEMENT tr (td|th)*>
347
348 <!ELEMENT td ANY>
349 <!ATTLIST td align (left|right|center) "center">
350
351 <!ELEMENT th ANY>
352 <!ATTLIST th align (left|right|center) "center">
353
354 <!ELEMENT ul (li)+>
355 <!ATTLIST ul type (disc|circle|square) "disc">
356
357 <!ELEMENT li ANY>
358 ]>
359
360 <specification label="JVM(TM) Tool Interface"
361 majorversion="1"
362 minorversion="1"
363 microversion="109">
364 <title subtitle="Version">
365 <tm>JVM</tm> Tool Interface
366 </title>
367
368 <intro id="whatIs" label="What is the JVM Tool Interface?">
369 The <tm>JVM</tm> Tool Interface (<jvmti/>)
370 is a programming interface used by development and monitoring tools.
371 It provides both a way to inspect the state and
372 to control the execution of applications running in the
373 <tm>Java</tm> virtual machine (VM).
374 <p/>
375 <jvmti/> is intended to provide a VM interface for the full breadth of tools
376 that need access to VM state, including but not limited to: profiling,
377 debugging, monitoring, thread analysis, and coverage analysis tools.
378 <p/>
379 <jvmti/> may not be available in all implementations of the <tm>Java</tm> virtual
380 machine.
381 <p/>
382 <jvmti/> is a two-way interface.
383 A client of <jvmti/>, hereafter called an <i>agent</i>,
384 can be notified of
385 interesting occurrences through <internallink id="EventSection">events</internallink>.
386 <jvmti/>
387 can query and control the application through many
388 <internallink id="FunctionSection">functions</internallink>,
389 either in response to events or
390 independent of them.
391 <p/>
392 Agents run in the same process with and communicate directly with
393 the virtual machine executing
394 the application being examined. This communication is
395 through a native interface (<jvmti/>). The native in-process interface allows
396 maximal control with minimal intrusion on the part of a tool.
397 Typically, agents are relatively compact. They can be controlled
398 by a separate process which implements the bulk of a tool's
399 function without interfering with the target application's normal execution.
400 </intro>
401
402 <intro id="architecture" label="Architecture">
403 Tools can be written directly to <jvmti/> or indirectly
404 through higher level interfaces.
405 The Java Platform Debugger Architecture includes <jvmti/>, but also
406 contains higher-level, out-of-process debugger interfaces. The higher-level
407 interfaces are more appropriate than <jvmti/> for many tools.
408 For more information on the Java Platform Debugger Architecture,
409 see the
410 <externallink id="http://java.sun.com/products/jpda/">Java
411 Platform Debugger Architecture website</externallink>.
412 </intro>
413
414 <intro id="writingAgents" label="Writing Agents">
415 Agents can be written in any native language that supports C
416 language calling conventions and C or C++
417 definitions.
418 <p/>
419 The function, event, data type, and constant definitions needed for
420 using <jvmti/> are defined in the include file <code>jvmti.h</code>.
421 To use these definitions add the <tm>J2SE</tm> include directory
422 to your include path and add
423 <example>
424 #include &lt;jvmti.h&gt;
425 </example>
426 to your source code.
427 </intro>
428
429 <intro id="deployingAgents" label="Deploying Agents">
430 An agent is deployed in a platform specific manner but is typically the
431 platform equivalent of a dynamic library. On the <tm>Windows</tm> operating
432 system, for example, an agent library is a "Dynamic Linked Library" (DLL).
433 On the <tm>Solaris</tm> Operating Environment, an agent library is a shared
434 object (<code>.so</code> file).
435 <p/>
436 An agent may be started at VM startup by specifying the agent library
437 name using a <internallink id="starting">command line option</internallink>.
438 Some implementations may support a mechanism to <internallink id="onattach">
439 start agents</internallink> in the live <functionlink id="GetPhase">phase</functionlink>.
440 The details of how this is initiated are implementation specific.
441 </intro>
442
443 <intro id="starting" label="Agent Command Line Options">
444 The term "command-line option" is used below to
445 mean options supplied in the <code>JavaVMInitArgs</code> argument
446 to the <code>JNI_CreateJavaVM</code> function of the JNI
447 Invocation API.
448 <p/>
449 One of the two following
450 command-line options is used on VM startup to
451 properly load and run agents.
452 These arguments identify the library containing
453 the agent as well as an options
454 string to be passed in at startup.
455 <dl>
456 <dt><code>-agentlib:</code><i>&lt;agent-lib-name&gt;</i><code>=</code><i>&lt;options&gt;</i></dt>
457 <dd>
458 The name following <code>-agentlib:</code> is the name of the
459 library to load. Lookup of the library, both its full name and location,
460 proceeds in a platform-specific manner.
461 Typically, the <i>&lt;agent-lib-name&gt;</i> is expanded to an
462 operating system specific file name.
463 The <i>&lt;options&gt;</i> will be passed to the agent on start-up.
464 For example, if the option
465 <code>-agentlib:foo=opt1,opt2</code> is specified, the VM will attempt to
466 load the shared library <code>foo.dll</code> from the system <code>PATH</code>
467 under <tm>Windows</tm> or <code>libfoo.so</code> from the
468 <code>LD_LIBRARY_PATH</code> under the <tm>Solaris</tm> operating environment.
469 </dd>
470 <dt><code>-agentpath:</code><i>&lt;path-to-agent&gt;</i><code>=</code><i>&lt;options&gt;</i></dt>
471 <dd>
472 The path following <code>-agentpath:</code> is the absolute path from which
473 to load the library.
474 No library name expansion will occur.
475 The <i>&lt;options&gt;</i> will be passed to the agent on start-up.
476 For example, if the option
477 <code>-agentpath:c:\myLibs\foo.dll=opt1,opt2</code> is specified, the VM will attempt to
478 load the shared library <code>c:\myLibs\foo.dll</code>.
479 </dd>
480 </dl>
481 The start-up routine <internallink id="onload"><code>Agent_OnLoad</code></internallink>
482 in the library will be invoked.
483 <p/>
484 Libraries loaded with <code>-agentlib:</code> or <code>-agentpath:</code>
485 will be searched for JNI native method implementations to facilitate the
486 use of Java programming language code in tools, as is needed for
487 <internallink id="bci">bytecode instrumentation</internallink>.
488 <p/>
489 The agent libraries will be searched after all other libraries have been
490 searched (agents wishing to override or intercept the native method
491 implementations of non-agent methods can use the
492 <eventlink id="NativeMethodBind">NativeMethodBind event</eventlink>).
493 <p/>
494 These switches do the above and nothing more - they do not change the
495 state of the VM or <jvmti/>. No command line options are needed
496 to enable <jvmti/>
497 or aspects of <jvmti/>, this is handled programmatically
498 by the use of
499 <internallink id="capability">capabilities</internallink>.
500 </intro>
501
502 <intro id="startup" label="Agent Start-Up">
503 The VM starts each agent by invoking a start-up function.
504 If the agent is started in the <code>OnLoad</code>
505 <functionlink id="GetPhase">phase</functionlink> the function
506 <internallink id="onload"><code>Agent_OnLoad</code></internallink>
507 will be invoked.
508 If the agent is started in the live
509 <functionlink id="GetPhase">phase</functionlink> the function
510 <internallink id="onattach"><code>Agent_OnAttach</code></internallink>
511 will be invoked.
512 Exactly one call to a start-up function is made per agent.
513 </intro>
514
515 <intro id="onload" label="Agent Start-Up (OnLoad phase)">
516 If an agent is started during the <code>OnLoad</code> phase then its
517 agent library must export a start-up function with the following prototype:
518 <example>
519 JNIEXPORT jint JNICALL
520 Agent_OnLoad(JavaVM *vm, char *options, void *reserved)</example>
521 The VM will start the agent by calling this function.
522 It will be called early enough in VM initialization that:
523 <ul>
524 <li><functionlink id="SetSystemProperty">system properties</functionlink>
525 may be set before they have been used in the start-up of the VM</li>
526 <li>the full set of
527 <internallink id="capability">capabilities</internallink>
528 is still available (note that capabilities that configure the VM
529 may only be available at this time--see the
530 <internallink id="capability">Capability function section</internallink>)</li>
531 <li>no bytecodes have executed</li>
532 <li>no classes have been loaded</li>
533 <li>no objects have been created</li>
534 </ul>
535 <p/>
536 The VM will call the <code>Agent_OnLoad</code> function with
537 <i>&lt;options&gt;</i> as the second argument -
538 that is, using the command-line option examples,
539 <code>"opt1,opt2"</code> will be passed to the <code>char *options</code>
540 argument of <code>Agent_OnLoad</code>.
541 The <code>options</code> argument is encoded as a
542 <internallink id="mUTF">modified UTF-8</internallink> string.
543 If <i>=&lt;options&gt;</i> is not specified,
544 a zero length string is passed to <code>options</code>.
545 The lifespan of the <code>options</code> string is the <code>Agent_OnLoad</code>
546 call. If needed beyond this time the string or parts of the string must
547 be copied.
548 The period between when <code>Agent_OnLoad</code> is called and when it
549 returns is called the <i>OnLoad phase</i>.
550 Since the VM is not initialized during the OnLoad
551 <functionlink id="GetPhase">phase</functionlink>,
552 the set of allowed operations
553 inside <code>Agent_OnLoad</code> is restricted (see the function descriptions for the
554 functionality available at this time).
555 The agent can safely process the options and set
556 event callbacks with <functionlink id="SetEventCallbacks"></functionlink>. Once
557 the VM initialization event is received
558 (that is, the <eventlink id="VMInit">VMInit</eventlink>
559 callback is invoked), the agent
560 can complete its initialization.
561 <rationale>
562 Early startup is required so that agents can set the desired capabilities,
563 many of which must be set before the VM is initialized.
564 In JVMDI, the -Xdebug command-line option provided
565 very coarse-grain control of capabilities.
566 JVMPI implementations use various tricks to provide a single "JVMPI on" switch.
567 No reasonable command-line
568 option could provide the fine-grain of control required to balance needed capabilities vs
569 performance impact.
570 Early startup is also needed so that agents can control the execution
571 environment - modifying the file system and system properties to install
572 their functionality.
573 </rationale>
574 <p/>
575 The return value from <code>Agent_OnLoad</code> is used to indicate an error.
576 Any value other than zero indicates an error and causes termination of the VM.
577 </intro>
578
579 <intro id="onattach" label="Agent Start-Up (Live phase)">
580 A VM may support a mechanism that allows agents to be started in the VM during the live
581 <functionlink id="GetPhase">phase</functionlink>. The details of how this is supported,
582 are implementation specific. For example, a tool may use some platform specific mechanism,
583 or implementation specific API, to attach to the running VM, and request it start a given
584 agent.
585 <p/>
586 If an agent is started during the live phase then its agent library
587 must export a start-up function
588 with the following prototype:
589 <example>
590 JNIEXPORT jint JNICALL
591 Agent_OnAttach(JavaVM* vm, char *options, void *reserved)</example>
592 <p/>
593 The VM will start the agent by calling this function.
594 It will be called in the context of a thread
595 that is attached to the VM. The first argument <i>&lt;vm&gt;</i> is the Java VM.
596 The <i>&lt;options&gt;</i> argument is the startup options provided to the agent.
597 <i>&lt;options&gt;</i> is encoded as a <internallink id="mUTF">modified UTF-8
598 </internallink> string.
599 If startup options were not provided, a zero length string is passed to
600 <code>options</code>. The lifespan of the <code>options</code> string is the
601 <code>Agent_OnAttach</code> call. If needed beyond this time the string or parts of
602 the string must be copied.
603 <p/>
604 Note that some <internallink id="capability">capabilities</internallink>
605 may not be available in the live phase.
606 <p/>
607 The <code>Agent_OnAttach</code> function initializes the agent and returns a value
608 to the VM to indicate if an error occurred. Any value other than zero indicates an error.
609 An error does not cause the VM to terminate. Instead the VM ignores the error, or takes
610 some implementation specific action -- for example it might print an error to standard error,
611 or record the error in a system log.
612 </intro>
613
614 <intro id="onunload" label="Agent Shutdown">
615 The library may optionally export a
616 shutdown function with the following prototype:
617 <example>
618 JNIEXPORT void JNICALL
619 Agent_OnUnload(JavaVM *vm)</example>
620 This function will be called by the VM when the library is about to be unloaded.
621 The library will be unloaded and this function will be called if some platform specific
622 mechanism causes the unload (an unload mechanism is not specified in this document)
623 or the library is (in effect) unloaded by the termination of the VM whether through
624 normal termination or VM failure, including start-up failure.
625 Uncontrolled shutdown is, of couse, an exception to this rule.
626 Note the distinction between this function and the
627 <eventlink id="VMDeath">VM Death event</eventlink>: for the VM Death event
628 to be sent, the VM must have run at least to the point of initialization and a valid
629 <jvmti/> environment must exist which has set a callback for VMDeath
630 and enabled the event
631 None of these are required for <code>Agent_OnUnload</code> and this function
632 is also called if the library is unloaded for other reasons.
633 In the case that a VM Death event is sent, it will be sent before this
634 function is called (assuming this function is called due to VM termination).
635 This function can be used to clean-up resources allocated by the agent.
636 </intro>
637
638 <intro id="tooloptions" label="JAVA_TOOL_OPTIONS">
639 Since the command-line cannot always be accessed or modified, for example in embedded VMs
640 or simply VMs launched deep within scripts, a <code>JAVA_TOOL_OPTIONS</code> variable is
641 provided so that agents may be launched in these cases.
642 <p/>
643 Platforms which support environment variables or other named strings, may support the
644 <code>JAVA_TOOL_OPTIONS</code> variable. This variable will be broken into options at white-space
645 boundaries. White-space characters include space, tab, carriage-return, new-line,
646 vertical-tab, and form-feed. Sequences of white-space characters are considered
647 equivalent to a single white-space character. No white-space is included in the options
648 unless quoted. Quoting is as follows:
649 <ul>
650 <li>All characters enclosed between a pair of single quote marks (''), except a single
651 quote, are quoted.</li>
652 <li>Double quote characters have no special meaning inside a pair of single quote marks.</li>
653 <li>All characters enclosed between a pair of double quote marks (""), except a double
654 quote, are quoted.</li>
655 <li>Single quote characters have no special meaning inside a pair of double quote marks.</li>
656 <li>A quoted part can start or end anywhere in the variable.</li>
657 <li>White-space characters have no special meaning when quoted -- they are included in
658 the option like any other character and do not mark white-space boundaries.</li>
659 <li>The pair of quote marks is not included in the option.</li>
660 </ul>
661 <code>JNI_CreateJavaVM</code> (in the JNI Invocation API) will prepend these options to the options supplied
662 in its <code>JavaVMInitArgs</code> argument. Platforms may disable this feature in cases where security is
663 a concern; for example, the Reference Implementation disables this feature on Unix systems when
664 the effective user or group ID differs from the real ID.
665 This feature is intended to support the initialization of tools -- specifically including the
666 launching of native or Java programming language agents. Multiple tools may wish to use this
667 feature, so the variable should not be overwritten, instead, options should be appended to
668 the variable. Note that since the variable is processed at the time of the JNI Invocation
669 API create VM call, options processed by a launcher (e.g., VM selection options) will not be handled.
670 </intro>
671
672 <intro id="environments" label="Environments">
673 The <jvmti/> specification supports the use of multiple simultaneous
674 <jvmti/> agents.
675 Each agent has its own <jvmti/> environment.
676 That is, the <jvmti/> state is
677 separate for each agent - changes to one environment do not affect the
678 others. The state of a <jvmti/>
679 environment includes:
680 <ul>
681 <li><functionlink id="SetEventCallbacks">the event callbacks</functionlink></li>
682 <li><functionlink id="SetEventNotificationMode">the set of events which are enabled</functionlink></li>
683 <li><internallink id="capability">the capabilities</internallink></li>
684 <li><internallink id="memory">the memory allocation/deallocation hooks</internallink></li>
685 </ul>
686 Although their <jvmti/> state
687 is separate, agents inspect and modify the shared state
688 of the VM, they also share the native environment in which they execute.
689 As such, an agent can perturb the results of other agents or cause them
690 to fail. It is the responsibility of the agent writer to specify the level
691 of compatibility with other agents. <jvmti/> implementations are not capable
692 of preventing destructive interactions between agents. Techniques to reduce
693 the likelihood of these occurrences are beyond the scope of this document.
694 <p/>
695 An agent creates a <jvmti/> environment
696 by passing a <jvmti/> version
697 as the interface ID to the JNI Invocation API function
698 <externallink id="http://java.sun.com/javase/6/docs/technotes/guides/jni/spec/invocation.html#GetEnv"><code>GetEnv</code></externallink>.
699 See <internallink id="jvmtiEnvAccess">Accessing <jvmti/> Functions</internallink>
700 for more details on the creation and use of
701 <jvmti/> environments.
702 Typically, <jvmti/> environments are created by calling <code>GetEnv</code> from
703 <internallink id="onload"><code>Agent_OnLoad</code></internallink>.
704 </intro>
705
706 <intro id="bci" label="Bytecode Instrumentation">
707 This interface does not include some events that one might expect in an interface with
708 profiling support. Some examples include object allocation events and full speed
709 method enter and exit events. The interface instead provides support for
710 <i>bytecode instrumentation</i>, the ability to alter the Java virtual machine
711 bytecode instructions which comprise the target program. Typically, these alterations
712 are to add "events" to the code of a method - for example, to add, at the beginning of a method,
713 a call to <code>MyProfiler.methodEntered()</code>.
714 Since the changes are purely additive, they do not modify application
715 state or behavior.
716 Because the inserted agent code is standard bytecodes, the VM can run at full speed,
717 optimizing not only the target program but also the instrumentation. If the
718 instrumentation does not involve switching from bytecode execution, no expensive
719 state transitions are needed. The result is high performance events.
720 This approach also provides complete control to the agent: instrumentation can be
721 restricted to "interesting" portions of the code (e.g., the end user's code) and
722 can be conditional. Instrumentation can run entirely in Java programming language
723 code or can call into the native agent. Instrumentation can simply maintain
724 counters or can statistically sample events.
725 <p/>
726 Instrumentation can be inserted in one of three ways:
727 <ul>
728 <li>
729 Static Instrumentation: The class file is instrumented before it
730 is loaded into the VM - for example, by creating a duplicate directory of
731 <code>*.class</code> files which have been modified to add the instrumentation.
732 This method is extremely awkward and, in general, an agent cannot know
733 the origin of the class files which will be loaded.
734 </li>
735 <li>
736 Load-Time Instrumentation: When a class file is loaded by the VM, the raw
737 bytes of the class file are sent for instrumentation to the agent.
738 The <eventlink id="ClassFileLoadHook"/>
739 event, triggered by the class load,
740 provides this functionality. This mechanism provides efficient
741 and complete access to one-time instrumentation.
742 </li>
743 <li>
744 Dynamic Instrumentation: A class which is already loaded (and possibly
745 even running) is modified. This optional feature is provided by the
746 <eventlink id="ClassFileLoadHook"/> event, triggered by calling the
747 <functionlink id="RetransformClasses"/> function.
748 Classes can be modified multiple times and can be returned to their
749 original state.
750 The mechanism allows instrumentation which changes during the
751 course of execution.
752 </li>
753 </ul>
754 <p/>
755 The class modification functionality provided in this interface
756 is intended to provide a mechanism for instrumentation
757 (the <eventlink id="ClassFileLoadHook"/> event
758 and the <functionlink id="RetransformClasses"/> function)
759 and, during development, for fix-and-continue debugging
760 (the <functionlink id="RedefineClasses"/> function).
761 <p/>
762 Care must be taken to avoid perturbing dependencies, especially when
763 instrumenting core classes. For example, an approach to getting notification
764 of every object allocation is to instrument the constructor on
765 <code>Object</code>. Assuming that the constructor is initially
766 empty, the constructor could be changed to:
767 <example>
768 public Object() {
769 MyProfiler.allocationTracker(this);
770 }
771 </example>
772 However, if this change was made using the
773 <eventlink id="ClassFileLoadHook"/>
774 event then this might impact a typical VM as follows:
775 the first created object will call the constructor causing a class load of
776 <code>MyProfiler</code>; which will then cause
777 object creation, and since <code>MyProfiler</code> isn't loaded yet,
778 infinite recursion; resulting in a stack overflow. A refinement of this
779 would be to delay invoking the tracking method until a safe time. For
780 example, <code>trackAllocations</code> could be set in the
781 handler for the <code>VMInit</code> event.
782 <example>
783 static boolean trackAllocations = false;
784
785 public Object() {
786 if (trackAllocations) {
787 MyProfiler.allocationTracker(this);
788 }
789 }
790 </example>
791 <p/>
792 The <functionlink id="SetNativeMethodPrefix"/> allows native methods
793 to be instrumented by the use of wrapper methods.
794 </intro>
795
796 <intro id="mUTF" label="Modified UTF-8 String Encoding">
797 <jvmti/> uses modified UTF-8 to encode character strings.
798 This is the same encoding used by JNI.
799 Modified UTF-8 differs
800 from standard UTF-8 in the representation of supplementary characters
801 and of the null character. See the
802 <externallink id="http://java.sun.com/javase/6/docs/technotes/guides/jni/spec/types.html#wp16542">
803 Modified UTF-8 Strings</externallink>
804 section of the JNI specification for details.
805 </intro>
806
807 <intro id="context" label="Specification Context">
808 Since this interface provides access to the state of applications running in the
809 Java virtual machine;
810 terminology refers to the Java platform and not the native
811 platform (unless stated otherwise). For example:
812 <ul>
813 <li>"thread" means Java programming language thread.</li>
814 <li>"stack frame" means Java virtual machine stack frame.</li>
815 <li>"class" means Java programming language class.</li>
816 <li>"heap" means Java virtual machine heap.</li>
817 <li>"monitor" means Java programming language object monitor.</li>
818 </ul>
819 <p/>
820 Sun, Sun Microsystems, the Sun logo, Java, and JVM
821 are trademarks or registered trademarks of Sun
822 Microsystems, Inc. in the U.S. and other countries.
823 </intro>
824
825
826 <functionsection label="Functions">
827 <intro id="jvmtiEnvAccess" label="Accessing Functions">
828 Native code accesses <jvmti/> features
829 by calling <jvmti/> functions.
830 Access to <jvmti/> functions is by use of an interface pointer
831 in the same manner as
832 <externallink id="http://java.sun.com/javase/6/docs/technotes/guides/jni/spec/design.html">Java
833 Native Interface (JNI) functions</externallink> are accessed.
834 The <jvmti/> interface pointer is called the
835 <i>environment pointer</i>.
836 <p/>
837 An environment pointer is a pointer to an environment and has
838 the type <code>jvmtiEnv*</code>.
839 An environment has information about its <jvmti/> connection.
840 The first value in the environment is a pointer to the function table.
841 The function table is an array of pointers to <jvmti/> functions.
842 Every function pointer is at a predefined offset inside the
843 array.
844 <p/>
845 When used from the C language:
846 double indirection is used to access the functions;
847 the environment pointer provides context and is the first
848 parameter of each function call; for example:
849 <example>
850 jvmtiEnv *jvmti;
851 ...
852 jvmtiError err = (*jvmti)->GetLoadedClasses(jvmti, &amp;class_count, &amp;classes);
853 </example>
854 <p/>
855 When used from the C++ language:
856 functions are accessed as member functions of <code>jvmtiEnv</code>;
857 the environment pointer is not passed to the function call; for example:
858 <example>
859 jvmtiEnv *jvmti;
860 ...
861 jvmtiError err = jvmti->GetLoadedClasses(&amp;class_count, &amp;classes);
862 </example>
863 Unless otherwise stated, all examples and declarations in this
864 specification use the C language.
865 <p/>
866 A <jvmti/> environment can be obtained through the JNI Invocation API
867 <code>GetEnv</code> function:
868 <example>
869 jvmtiEnv *jvmti;
870 ...
871 (*jvm)->GetEnv(jvm, &amp;jvmti, JVMTI_VERSION_1_0);
872 </example>
873 Each call to <code>GetEnv</code>
874 creates a new <jvmti/> connection and thus
875 a new <jvmti/> environment.
876 The <code>version</code> argument of <code>GetEnv</code> must be
877 a <jvmti/> version.
878 The returned environment may have a different version than the
879 requested version but the returned environment must be compatible.
880 <code>GetEnv</code> will return <code>JNI_EVERSION</code> if a
881 compatible version is not available, if <jvmti/> is not supported or
882 <jvmti/> is not supported in the current VM configuration.
883 Other interfaces may be added for creating <jvmti/> environments
884 in specific contexts.
885 Each environment has its own state (for example,
886 <functionlink id="SetEventNotificationMode">desired events</functionlink>,
887 <functionlink id="SetEventCallbacks">event handling functions</functionlink>, and
888 <functionlink id="AddCapabilities">capabilities</functionlink>).
889 An environment is released with
890 <functionlink id="DisposeEnvironment"></functionlink>.
891 Thus, unlike JNI which has one environment per thread, <jvmti/> environments work
892 across threads and are created dynamically.
893 </intro>
894
895 <intro id="functionReturn" label="Function Return Values">
896 <jvmti/> functions always return an
897 <internallink id="ErrorSection">error code</internallink> via the
898 <datalink id="jvmtiError"/> function return value.
899 Some functions can return additional
900 values through pointers provided by the calling function.
901 In some cases, <jvmti/> functions allocate memory that your program must
902 explicitly deallocate. This is indicated in the individual <jvmti/>
903 function descriptions. Empty lists, arrays, sequences, etc are
904 returned as <code>NULL</code>.
905 <p/>
906 In the event that the <jvmti/> function encounters
907 an error (any return value other than <code>JVMTI_ERROR_NONE</code>) the values
908 of memory referenced by argument pointers is undefined, but no memory
909 will have been allocated and no global references will have been allocated.
910 If the error occurs because of invalid input, no action will have occurred.
911 </intro>
912
913 <intro id="refs" label="Managing JNI Object References">
914 <jvmti/> functions identify objects with JNI references
915 (<datalink id="jobject"/> and <datalink id="jclass"/>)
916 and their derivatives
917 (<datalink id="jthread"/> and <datalink id="jthreadGroup"/>).
918 References passed to
919 <jvmti/> functions can be either global or local, but they must be
920 strong references. All references returned by <jvmti/> functions are
921 local references--these local references are created
922 during the <jvmti/> call.
923 Local references are a resource that must be managed (see the
924 <externallink id="http://java.sun.com/javase/6/docs/guide/jni/spec/functions.html#wp18654">JNI Documentation</externallink>).
925 When threads return from native code all local references
926 are freed. Note that some threads, including typical
927 agent threads, will never return from native code.
928 A thread is ensured the ability to create sixteen local
929 references without the need for any explicit management.
930 For threads executing a limited number of <jvmti/> calls before
931 returning from native code
932 (for example, threads processing events),
933 it may be determined that no explicit management
934 is needed.
935 However, long running agent threads will need explicit
936 local reference management--usually with the JNI functions
937 <code>PushLocalFrame</code> and <code>PopLocalFrame</code>.
938 Conversely, to preserve references beyond the
939 return from native code, they must be converted to global references.
940 These rules do not apply to <datalink id="jmethodID"/> and <datalink id="jfieldID"/>
941 as they are not <datalink id="jobject"/>s.
942 </intro>
943
944 <intro id="prereqState" label="Prerequisite State for Calling Functions">
945 Unless the function explicitly states that the agent must bring
946 a thread or the VM to a particular state (for example, suspended),
947 the <jvmti/> implementation is responsible for bringing the VM to a
948 safe and consistent state for performing the function.
949 </intro>
950
951 <intro id="functionsExceptions" label="Exceptions and Functions">
952 <jvmti/> functions never throw exceptions; error conditions are
953 communicated via the
954 <internallink id="functionReturn">function return value</internallink>.
955 Any existing exception state is preserved across a call to a
956 <jvmti/> function.
957 See the
958 <externallink
959 id="http://java.sun.com/javase/6/docs/technotes/guides/jni/spec/design.html#wp770"
960 >Java Exceptions</externallink>
961 section of the JNI specification for information on handling exceptions.
962 </intro>
963
964 <category id="memory" label="Memory Management">
965 <intro>
966 These functions provide for the allocation and deallocation of
967 memory used by <jvmti/> functionality and can be used to provide
968 working memory for agents.
969 Memory managed by <jvmti/> is not compatible with other memory
970 allocation libraries and mechanisms.
971 </intro>
972
973 <function id="Allocate" jkernel="yes" phase="any" callbacksafe="safe" impl="notrace" num="46">
974 <synopsis>Allocate</synopsis>
975 <description>
976 Allocate an area of memory through the <jvmti/> allocator.
977 The allocated
978 memory should be freed with <functionlink id="Deallocate"></functionlink>.
979 </description>
980 <origin>jvmdi</origin>
981 <capabilities>
982 </capabilities>
983 <parameters>
984 <param id="size">
985 <jlong/>
986 <description>
987 The number of bytes to allocate.
988 <rationale>
989 <code>jlong</code> is used for compatibility with JVMDI.
990 </rationale>
991 </description>
992 </param>
993 <param id="mem_ptr">
994 <allocbuf incount="size"><uchar/></allocbuf>
995 <description>
996 On return, a pointer to the beginning of the allocated memory.
997 If <code>size</code> is zero, <code>NULL</code> is returned.
998 </description>
999 </param>
1000 </parameters>
1001 <errors>
1002 <error id="JVMTI_ERROR_OUT_OF_MEMORY">
1003 Memory request cannot be honored.
1004 </error>
1005 <error id="JVMTI_ERROR_ILLEGAL_ARGUMENT">
1006 <paramlink id="size"></paramlink> is less than zero.
1007 </error>
1008 </errors>
1009 </function>
1010
1011 <function id="Deallocate" jkernel="yes" phase="any" callbacksafe="safe" impl="notrace" num="47">
1012 <synopsis>Deallocate</synopsis>
1013 <description>
1014 Deallocate <code>mem</code> using the <jvmti/> allocator.
1015 This function should
1016 be used to deallocate any memory allocated and returned
1017 by a <jvmti/> function
1018 (including memory allocated with <functionlink id="Allocate"></functionlink>).
1019 All allocated memory must be deallocated
1020 or the memory cannot be reclaimed.
1021 </description>
1022 <origin>jvmdi</origin>
1023 <capabilities>
1024 </capabilities>
1025 <parameters>
1026 <param id="mem">
1027 <outbuf>
1028 <uchar/>
1029 <nullok>the call is ignored</nullok>
1030 </outbuf>
1031 <description>
1032 A pointer to the beginning of the allocated memory.
1033 Please ignore "On return, the elements are set."
1034 <todo>keep it from generating "On return, the elements are set"</todo>
1035 </description>
1036 </param>
1037 </parameters>
1038 <errors>
1039 </errors>
1040 </function>
1041 </category>
1042
1043 <category id="threadCategory" label="Thread">
1044 <intro>
1045 </intro>
1046
1047 <function id="GetThreadState" num="17">
1048 <synopsis>Get Thread State</synopsis>
1049 <description>
1050 Get the state of a thread. The state of the thread is represented by the
1051 answers to the hierarchical set of questions below:
1052 <ul type="circle">
1053 <li><i>Alive?</i>
1054 <ul>
1055 <li>Not alive.
1056 <ul type="circle">
1057 <li><i>Why not alive?</i>
1058 <ul>
1059 <li>New.</li>
1060 <li>Terminated (<datalink
1061 id="JVMTI_THREAD_STATE_TERMINATED"><code>JVMTI_THREAD_STATE_TERMINATED</code></datalink>)</li>
1062 </ul>
1063 </li>
1064 </ul>
1065 </li>
1066 <li>Alive (<datalink
1067 id="JVMTI_THREAD_STATE_ALIVE"><code>JVMTI_THREAD_STATE_ALIVE</code></datalink>)
1068 <ul type="circle">
1069 <li><i>Suspended?</i>
1070 <ul>
1071 <li>Suspended (<datalink
1072 id="JVMTI_THREAD_STATE_SUSPENDED"><code>JVMTI_THREAD_STATE_SUSPENDED</code></datalink>)</li>
1073 <li>Not suspended</li>
1074 </ul>
1075 </li>
1076 <li><i>Interrupted?</i>
1077 <ul>
1078 <li>Interrupted (<datalink
1079 id="JVMTI_THREAD_STATE_INTERRUPTED"><code>JVMTI_THREAD_STATE_INTERRUPTED</code></datalink>)</li>
1080 <li>Not interrupted.</li>
1081 </ul>
1082 </li>
1083 <li><i>In native?</i>
1084 <ul>
1085 <li>In native code (<datalink
1086 id="JVMTI_THREAD_STATE_IN_NATIVE"><code>JVMTI_THREAD_STATE_IN_NATIVE</code></datalink>)</li>
1087 <li>In Java programming language code</li>
1088 </ul>
1089 </li>
1090 <li><i>What alive state?</i>
1091 <ul>
1092 <li>Runnable (<datalink
1093 id="JVMTI_THREAD_STATE_RUNNABLE"><code>JVMTI_THREAD_STATE_RUNNABLE</code></datalink>)</li>
1094 <li>Blocked (<datalink
1095 id="JVMTI_THREAD_STATE_BLOCKED_ON_MONITOR_ENTER"><code>JVMTI_THREAD_STATE_BLOCKED_ON_MONITOR_ENTER</code></datalink>)</li>
1096 <li>Waiting (<datalink
1097 id="JVMTI_THREAD_STATE_WAITING"><code>JVMTI_THREAD_STATE_WAITING</code></datalink>)
1098 <ul type="circle">
1099 <li><i>Timed wait?</i>
1100 <ul>
1101 <li>Indefinite (<datalink
1102 id="JVMTI_THREAD_STATE_WAITING_INDEFINITELY"><code>JVMTI_THREAD_STATE_WAITING_INDEFINITELY</code></datalink></li>
1103 <li>Timed (<datalink
1104 id="JVMTI_THREAD_STATE_WAITING_WITH_TIMEOUT"><code>JVMTI_THREAD_STATE_WAITING_WITH_TIMEOUT</code></datalink>)</li>
1105 </ul>
1106 </li>
1107 <li><i>Why waiting?</i>
1108 <ul>
1109 <li>Object.wait (<datalink
1110 id="JVMTI_THREAD_STATE_IN_OBJECT_WAIT"><code>JVMTI_THREAD_STATE_IN_OBJECT_WAIT</code></datalink>)</li>
1111 <li>LockSupport.park (<datalink
1112 id="JVMTI_THREAD_STATE_PARKED"><code>JVMTI_THREAD_STATE_PARKED</code></datalink>)</li>
1113 <li>Sleeping (<datalink
1114 id="JVMTI_THREAD_STATE_SLEEPING"><code>JVMTI_THREAD_STATE_SLEEPING</code></datalink>)</li>
1115 </ul>
1116 </li>
1117 </ul>
1118 </li>
1119 </ul>
1120 </li>
1121 </ul>
1122 </li>
1123 </ul>
1124 </li>
1125 </ul>
1126 <p/>
1127 The answers are represented by the following bit vector.
1128 <constants id="jvmtiThreadState" label="Thread State Flags" kind="bits">
1129 <constant id="JVMTI_THREAD_STATE_ALIVE" num="0x0001">
1130 Thread is alive. Zero if thread is new (not started) or terminated.
1131 </constant>
1132 <constant id="JVMTI_THREAD_STATE_TERMINATED" num="0x0002">
1133 Thread has completed execution.
1134 </constant>
1135 <constant id="JVMTI_THREAD_STATE_RUNNABLE" num="0x0004">
1136 Thread is runnable.
1137 </constant>
1138 <constant id="JVMTI_THREAD_STATE_BLOCKED_ON_MONITOR_ENTER" num="0x0400">
1139 Thread is waiting to enter a synchronization block/method or,
1140 after an <code>Object.wait()</code>, waiting to re-enter a
1141 synchronization block/method.
1142 </constant>
1143 <constant id="JVMTI_THREAD_STATE_WAITING" num="0x0080">
1144 Thread is waiting.
1145 </constant>
1146 <constant id="JVMTI_THREAD_STATE_WAITING_INDEFINITELY" num="0x0010">
1147 Thread is waiting without a timeout.
1148 For example, <code>Object.wait()</code>.
1149 </constant>
1150 <constant id="JVMTI_THREAD_STATE_WAITING_WITH_TIMEOUT" num="0x0020">
1151 Thread is waiting with a maximum time to wait specified.
1152 For example, <code>Object.wait(long)</code>.
1153 </constant>
1154 <constant id="JVMTI_THREAD_STATE_SLEEPING" num="0x0040">
1155 Thread is sleeping -- <code>Thread.sleep(long)</code>.
1156 </constant>
1157 <constant id="JVMTI_THREAD_STATE_IN_OBJECT_WAIT" num="0x0100">
1158 Thread is waiting on an object monitor -- <code>Object.wait</code>.
1159 </constant>
1160 <constant id="JVMTI_THREAD_STATE_PARKED" num="0x0200">
1161 Thread is parked, for example: <code>LockSupport.park</code>,
1162 <code>LockSupport.parkUtil</code> and <code>LockSupport.parkNanos</code>.
1163 </constant>
1164 <constant id="JVMTI_THREAD_STATE_SUSPENDED" num="0x100000">
1165 Thread suspended.
1166 <code>java.lang.Thread.suspend()</code>
1167 or a <jvmti/> suspend function
1168 (such as <functionlink id="SuspendThread"></functionlink>)
1169 has been called on the thread. If this bit
1170 is set, the other bits refer to the thread state before suspension.
1171 </constant>
1172 <constant id="JVMTI_THREAD_STATE_INTERRUPTED" num="0x200000">
1173 Thread has been interrupted.
1174 </constant>
1175 <constant id="JVMTI_THREAD_STATE_IN_NATIVE" num="0x400000">
1176 Thread is in native code--that is, a native method is running
1177 which has not called back into the VM or Java programming
1178 language code.
1179 <p/>
1180 This flag is not set when running VM compiled Java programming
1181 language code nor is it set when running VM code or
1182 VM support code. Native VM interface functions, such as JNI and
1183 <jvmti/> functions, may be implemented as VM code.
1184 </constant>
1185 <constant id="JVMTI_THREAD_STATE_VENDOR_1" num="0x10000000">
1186 Defined by VM vendor.
1187 </constant>
1188 <constant id="JVMTI_THREAD_STATE_VENDOR_2" num="0x20000000">
1189 Defined by VM vendor.
1190 </constant>
1191 <constant id="JVMTI_THREAD_STATE_VENDOR_3" num="0x40000000">
1192 Defined by VM vendor.
1193 </constant>
1194 </constants>
1195 The following definitions are used to convert <jvmti/> thread state
1196 to <code>java.lang.Thread.State</code> style states.
1197 <constants id="jvmtiJavaLangThreadState" label="java.lang.Thread.State Conversion Masks" kind="bits">
1198 <constant id="JVMTI_JAVA_LANG_THREAD_STATE_MASK"
1199 num="JVMTI_THREAD_STATE_TERMINATED | JVMTI_THREAD_STATE_ALIVE | JVMTI_THREAD_STATE_RUNNABLE | JVMTI_THREAD_STATE_BLOCKED_ON_MONITOR_ENTER | JVMTI_THREAD_STATE_WAITING | JVMTI_THREAD_STATE_WAITING_INDEFINITELY | JVMTI_THREAD_STATE_WAITING_WITH_TIMEOUT">
1200 Mask the state with this before comparison
1201 </constant>
1202 <constant id="JVMTI_JAVA_LANG_THREAD_STATE_NEW"
1203 num="0">
1204 <code>java.lang.Thread.State.NEW</code>
1205 </constant>
1206 <constant id="JVMTI_JAVA_LANG_THREAD_STATE_TERMINATED"
1207 num="JVMTI_THREAD_STATE_TERMINATED">
1208 <code>java.lang.Thread.State.TERMINATED</code>
1209 </constant>
1210 <constant id="JVMTI_JAVA_LANG_THREAD_STATE_RUNNABLE"
1211 num="JVMTI_THREAD_STATE_ALIVE | JVMTI_THREAD_STATE_RUNNABLE">
1212 <code>java.lang.Thread.State.RUNNABLE</code>
1213 </constant>
1214 <constant id="JVMTI_JAVA_LANG_THREAD_STATE_BLOCKED"
1215 num="JVMTI_THREAD_STATE_ALIVE | JVMTI_THREAD_STATE_BLOCKED_ON_MONITOR_ENTER">
1216 <code>java.lang.Thread.State.BLOCKED</code>
1217 </constant>
1218 <constant id="JVMTI_JAVA_LANG_THREAD_STATE_WAITING"
1219 num="JVMTI_THREAD_STATE_ALIVE | JVMTI_THREAD_STATE_WAITING | JVMTI_THREAD_STATE_WAITING_INDEFINITELY">
1220 <code>java.lang.Thread.State.WAITING</code>
1221 </constant>
1222 <constant id="JVMTI_JAVA_LANG_THREAD_STATE_TIMED_WAITING"
1223 num="JVMTI_THREAD_STATE_ALIVE | JVMTI_THREAD_STATE_WAITING | JVMTI_THREAD_STATE_WAITING_WITH_TIMEOUT">
1224 <code>java.lang.Thread.State.TIMED_WAITING</code>
1225 </constant>
1226 </constants>
1227 <b>Rules</b>
1228 <p/>
1229 There can be no more than one answer to a question, although there can be no
1230 answer (because the answer is unknown, does not apply, or none of the answers is
1231 correct). An answer is set only when the enclosing answers match.
1232 That is, no more than one of
1233 <ul type="circle">
1234 <li><code>JVMTI_THREAD_STATE_RUNNABLE</code></li>
1235 <li><code>JVMTI_THREAD_STATE_BLOCKED_ON_MONITOR_ENTER</code></li>
1236 <li><code>JVMTI_THREAD_STATE_WAITING</code></li>
1237 </ul>
1238 can be set (a <tm>J2SE</tm> compliant implementation will always set
1239 one of these if <code>JVMTI_THREAD_STATE_ALIVE</code> is set).
1240 And if any of these are set, the enclosing answer
1241 <code>JVMTI_THREAD_STATE_ALIVE</code> is set.
1242 No more than one of
1243 <ul type="circle">
1244 <li><code>JVMTI_THREAD_STATE_WAITING_INDEFINITELY</code></li>
1245 <li><code>JVMTI_THREAD_STATE_WAITING_WITH_TIMEOUT</code></li>
1246 </ul>
1247 can be set (a <tm>J2SE</tm> compliant implementation will always set
1248 one of these if <code>JVMTI_THREAD_STATE_WAITING</code> is set).
1249 And if either is set, the enclosing answers
1250 <code>JVMTI_THREAD_STATE_ALIVE</code> and
1251 <code>JVMTI_THREAD_STATE_WAITING</code> are set.
1252 No more than one of
1253 <ul type="circle">
1254 <li><code>JVMTI_THREAD_STATE_IN_OBJECT_WAIT</code></li>
1255 <li><code>JVMTI_THREAD_STATE_PARKED</code></li>
1256 <li><code>JVMTI_THREAD_STATE_SLEEPING</code></li>
1257 </ul>
1258 can be set. And if any of these is set, the enclosing answers
1259 <code>JVMTI_THREAD_STATE_ALIVE</code> and
1260 <code>JVMTI_THREAD_STATE_WAITING</code> are set.
1261 Also, if <code>JVMTI_THREAD_STATE_SLEEPING</code> is set,
1262 then <code>JVMTI_THREAD_STATE_WAITING_WITH_TIMEOUT</code> is set.
1263 If a state <i>A</i> is implemented using the mechanism of
1264 state <i>B</i> then it is state <i>A</i> which
1265 is returned by this function.
1266 For example, if <code>Thread.sleep(long)</code>
1267 is implemented using <code>Object.wait(long)</code>
1268 then it is still <code>JVMTI_THREAD_STATE_SLEEPING</code>
1269 which is returned.
1270 More than one of
1271 <ul type="circle">
1272 <li><code>JVMTI_THREAD_STATE_SUSPENDED</code></li>
1273 <li><code>JVMTI_THREAD_STATE_INTERRUPTED</code></li>
1274 <li><code>JVMTI_THREAD_STATE_IN_NATIVE</code></li>
1275 </ul>
1276 can be set, but if any is set,
1277 <code>JVMTI_THREAD_STATE_ALIVE</code> is set.
1278 <p/>
1279 And finally,
1280 <code>JVMTI_THREAD_STATE_TERMINATED</code> cannot be set unless
1281 <code>JVMTI_THREAD_STATE_ALIVE</code> is not set.
1282 <p/>
1283 The thread state representation is designed for extension in future versions
1284 of the specification; thread state values should be used accordingly, that is
1285 they should not be used as ordinals.
1286 Most queries can be made by testing a single bit, if use in a switch statement is desired,
1287 the state bits should be masked with the interesting bits.
1288 All bits not defined above are reserved for future use.
1289 A VM, compliant to the current specification, must set reserved bits to zero.
1290 An agent should ignore reserved bits --
1291 they should not be assumed to be zero and thus should not be included in comparisons.
1292 <p/>
1293 <b>Examples</b>
1294 <p/>
1295 Note that the values below exclude reserved and vendor bits.
1296 <p/>
1297 The state of a thread blocked at a <code>synchronized</code>-statement would be:
1298 <example>
1299 JVMTI_THREAD_STATE_ALIVE + JVMTI_THREAD_STATE_BLOCKED_ON_MONITOR_ENTER
1300 </example>
1301 The state of a thread which hasn't started yet would be:
1302 <example>
1303 0
1304 </example>
1305 The state of a thread at a <code>Object.wait(3000)</code> would be:
1306 <example>
1307 JVMTI_THREAD_STATE_ALIVE + JVMTI_THREAD_STATE_WAITING +
1308 JVMTI_THREAD_STATE_WAITING_WITH_TIMEOUT +
1309 JVMTI_THREAD_STATE_MONITOR_WAITING
1310 </example>
1311 The state of a thread suspended while runnable would be:
1312 <example>
1313 JVMTI_THREAD_STATE_ALIVE + JVMTI_THREAD_STATE_RUNNABLE + JVMTI_THREAD_STATE_SUSPENDED
1314 </example>
1315 <p/>
1316 <b>Testing the State</b>
1317 <p/>
1318 In most cases, the thread state can be determined by testing the one bit corresponding
1319 to that question. For example, the code to test if a thread is sleeping:
1320 <example>
1321 jint state;
1322 jvmtiError err;
1323
1324 err = (*jvmti)-&gt;GetThreadState(jvmti, thread, &amp;state);
1325 if (err == JVMTI_ERROR_NONE) {
1326 if (state &amp; JVMTI_THREAD_STATE_SLEEPING) { ...
1327 </example>
1328 <p/>
1329 For waiting (that is, in <code>Object.wait</code>, parked, or sleeping) it would be:
1330 <example>
1331 if (state &amp; JVMTI_THREAD_STATE_WAITING) { ...
1332 </example>
1333 For some states, more than one bit will need to be tested as is the case
1334 when testing if a thread has not yet been started:
1335 <example>
1336 if ((state &amp; (JVMTI_THREAD_STATE_ALIVE | JVMTI_THREAD_STATE_TERMINATED)) == 0) { ...
1337 </example>
1338 To distinguish timed from untimed <code>Object.wait</code>:
1339 <example>
1340 if (state &amp; JVMTI_THREAD_STATE_IN_OBJECT_WAIT) {
1341 if (state &amp; JVMTI_THREAD_STATE_WAITING_WITH_TIMEOUT) {
1342 printf("in Object.wait(long timeout)\n");
1343 } else {
1344 printf("in Object.wait()\n");
1345 }
1346 }
1347 </example>
1348 <p/>
1349 <b>Relationship to <code>java.lang.Thread.State</code></b>
1350 <p/>
1351 The thread state represented by <code>java.lang.Thread.State</code>
1352 returned from <code>java.lang.Thread.getState()</code> is a subset of the
1353 information returned from this function.
1354 The corresponding <code>java.lang.Thread.State</code> can be determined
1355 by using the provided conversion masks.
1356 For example, this returns the name of the <code>java.lang.Thread.State</code> thread state:
1357 <example>
1358 err = (*jvmti)-&gt;GetThreadState(jvmti, thread, &amp;state);
1359 abortOnError(err);
1360 switch (state &amp; JVMTI_JAVA_LANG_THREAD_STATE_MASK) {
1361 case JVMTI_JAVA_LANG_THREAD_STATE_NEW:
1362 return "NEW";
1363 case JVMTI_JAVA_LANG_THREAD_STATE_TERMINATED:
1364 return "TERMINATED";
1365 case JVMTI_JAVA_LANG_THREAD_STATE_RUNNABLE:
1366 return "RUNNABLE";
1367 case JVMTI_JAVA_LANG_THREAD_STATE_BLOCKED:
1368 return "BLOCKED";
1369 case JVMTI_JAVA_LANG_THREAD_STATE_WAITING:
1370 return "WAITING";
1371 case JVMTI_JAVA_LANG_THREAD_STATE_TIMED_WAITING:
1372 return "TIMED_WAITING";
1373 }
1374 </example>
1375 </description>
1376 <origin>new</origin>
1377 <capabilities>
1378 </capabilities>
1379 <parameters>
1380 <param id="thread">
1381 <jthread null="current" started="maybe" impl="noconvert"/>
1382 <description>
1383 The thread to query.
1384 </description>
1385 </param>
1386 <param id="thread_state_ptr">
1387 <outptr><jint/></outptr>
1388 <description>
1389 On return, points to state flags,
1390 as defined by the <internallink id="jvmtiThreadState">Thread State Flags</internallink>.
1391 </description>
1392 </param>
1393 </parameters>
1394 <errors>
1395 </errors>
1396 </function>
1397
1398 <function id="GetCurrentThread" phase="start" num="18" since="1.1">
1399 <synopsis>Get Current Thread</synopsis>
1400 <description>
1401 Get the current thread.
1402 The current thread is the Java programming language thread which has called the function.
1403 <p/>
1404 Note that most <jvmti/> functions that take a thread
1405 as an argument will accept <code>NULL</code> to mean
1406 the current thread.
1407 </description>
1408 <origin>new</origin>
1409 <capabilities>
1410 </capabilities>
1411 <parameters>
1412 <param id="thread_ptr">
1413 <outptr><jthread/></outptr>
1414 <description>
1415 On return, points to the current thread.
1416 </description>
1417 </param>
1418 </parameters>
1419 <errors>
1420 </errors>
1421 </function>
1422
1423 <function id="GetAllThreads" num="4">
1424 <synopsis>Get All Threads</synopsis>
1425 <description>
1426 Get all live threads.
1427 The threads are Java programming language threads;
1428 that is, threads that are attached to the VM.
1429 A thread is live if <code>java.lang.Thread.isAlive()</code>
1430 would return <code>true</code>, that is, the thread has
1431 been started and has not yet died.
1432 The universe of threads is determined by the context of the <jvmti/>
1433 environment, which typically is all threads attached to the VM.
1434 Note that this includes <jvmti/> agent threads
1435 (see <functionlink id="RunAgentThread"/>).
1436 </description>
1437 <origin>jvmdi</origin>
1438 <capabilities>
1439 </capabilities>
1440 <parameters>
1441 <param id="threads_count_ptr">
1442 <outptr><jint/></outptr>
1443 <description>
1444 On return, points to the number of running threads.
1445 </description>
1446 </param>
1447 <param id="threads_ptr">
1448 <allocbuf outcount="threads_count_ptr"><jthread/></allocbuf>
1449 <description>
1450 On return, points to an array of references, one
1451 for each running thread.
1452 </description>
1453 </param>
1454 </parameters>
1455 <errors>
1456 </errors>
1457 </function>
1458
1459 <function id="SuspendThread" num="5">
1460 <synopsis>Suspend Thread</synopsis>
1461 <description>
1462 Suspend the specified thread. If the calling thread is specified,
1463 this function will not return until some other thread calls
1464 <functionlink id="ResumeThread"></functionlink>.
1465 If the thread is currently suspended, this function
1466 does nothing and returns an error.
1467 </description>
1468 <origin>jvmdi</origin>
1469 <capabilities>
1470 <required id="can_suspend"></required>
1471 </capabilities>
1472 <parameters>
1473 <param id="thread">
1474 <jthread null="current"/>
1475 <description>
1476 The thread to suspend.
1477 </description>
1478 </param>
1479 </parameters>
1480 <errors>
1481 <error id="JVMTI_ERROR_THREAD_SUSPENDED">
1482 Thread already suspended.
1483 </error>
1484 </errors>
1485 </function>
1486
1487 <elide>
1488 <function id="SuspendAllThreads" num="101">
1489 <synopsis>Suspend All Threads</synopsis>
1490 <description>
1491 <issue>
1492 There has been no explicit call for this function, and it will
1493 thus be removed if there is no interest.
1494 </issue>
1495 Suspend all live threads except:
1496 <ul>
1497 <li>already suspended threads</li>
1498 <li>those listed in <paramlink id="except_list"></paramlink></li>
1499 <li>certain system (non application) threads, as determined
1500 by the VM implementation</li>
1501 </ul>
1502 The threads are Java programming language threads;
1503 native threads which are not attached to the VM are not
1504 Java programming language threads.
1505 A thread is live if <code>java.lang.Thread.isAlive()</code>
1506 would return <code>true</code>, that is, the thread has
1507 been started and has not yet died.
1508 The universe of threads is determined
1509 by the context of the <jvmti/>
1510 environment, which, typically, is all threads attached to the VM,
1511 except critical VM internal threads and <jvmti/> agent threads
1512 (see <functionlink id="RunAgentThread"/>).
1513 <p/>
1514 If the calling thread is specified,
1515 all other threads are suspended first then the caller thread is suspended -
1516 this function will not return until some other thread calls
1517 <functionlink id="ResumeThread"></functionlink>.
1518 <p/>
1519 The list of actually
1520 suspended threads is returned in
1521 <paramlink id="suspended_list_ptr"></paramlink>.
1522 Suspension is as defined in <functionlink id="SuspendThread"></functionlink>.
1523 <functionlink id="ResumeThreadList"></functionlink>
1524 can be used to resume the suspended threads.
1525 </description>
1526 <origin>new</origin>
1527 <capabilities>
1528 <required id="can_suspend"></required>
1529 </capabilities>
1530 <parameters>
1531 <param id="except_count">
1532 <jint min="0"/>
1533 <description>
1534 The number of threads in the list of threads not to be suspended.
1535 </description>
1536 </param>
1537 <param id="except_list">
1538 <inbuf incount="except_count">
1539 <jthread/>
1540 <nullok>not an error if <code>except_count == 0</code></nullok>
1541 </inbuf>
1542 <description>
1543 The list of threads not to be suspended.
1544 </description>
1545 </param>
1546 <param id="suspended_count_ptr">
1547 <outptr><jint/></outptr>
1548 <description>
1549 On return, points to the number of threads suspended by this call.
1550 </description>
1551 </param>
1552 <param id="suspended_list_ptr">
1553 <allocbuf outcount="suspended_count_ptr"><jthread/></allocbuf>
1554 <description>
1555 On return, points to an array of references, one
1556 for each thread suspended.
1557 </description>
1558 </param>
1559 </parameters>
1560 <errors>
1561 <error id="JVMTI_ERROR_INVALID_THREAD">
1562 A thread in <paramlink id="except_list"></paramlink> was invalid.
1563 </error>
1564 <error id="JVMTI_ERROR_NULL_POINTER">
1565 Both <paramlink id="except_list"></paramlink> was <code>NULL</code>
1566 and <paramlink id="except_count"></paramlink> was non-zero.
1567 </error>
1568 </errors>
1569 </function>
1570 </elide>
1571
1572 <function id="SuspendThreadList" num="92">
1573 <synopsis>Suspend Thread List</synopsis>
1574 <description>
1575 Suspend the <paramlink id="request_count"></paramlink>
1576 threads specified in the
1577 <paramlink id="request_list"></paramlink> array.
1578 Threads may be resumed with
1579 <functionlink id="ResumeThreadList"></functionlink> or
1580 <functionlink id="ResumeThread"></functionlink>.
1581 If the calling thread is specified in the
1582 <paramlink id="request_list"></paramlink> array, this function will
1583 not return until some other thread resumes it.
1584 Errors encountered in the suspension of a thread
1585 are returned in the <paramlink id="results"></paramlink>
1586 array, <b>not</b> in the return value of this function.
1587 Threads that are currently suspended do not change state.
1588 </description>
1589 <origin>jvmdi</origin>
1590 <capabilities>
1591 <required id="can_suspend"></required>
1592 </capabilities>
1593 <parameters>
1594 <param id="request_count">
1595 <jint min="0"/>
1596 <description>
1597 The number of threads to suspend.
1598 </description>
1599 </param>
1600 <param id="request_list">
1601 <inbuf incount="request_count"><jthread/></inbuf>
1602 <description>
1603 The list of threads to suspend.
1604 </description>
1605 </param>
1606 <param id="results">
1607 <outbuf incount="request_count"><enum>jvmtiError</enum></outbuf>
1608 <description>
1609 An agent supplied array of
1610 <paramlink id="request_count"></paramlink> elements.
1611 On return, filled with the error code for
1612 the suspend of the corresponding thread.
1613 The error code will be
1614 <errorlink id="JVMTI_ERROR_NONE"></errorlink>
1615 if the thread was suspended by this call.
1616 Possible error codes are those specified
1617 for <functionlink id="SuspendThread"></functionlink>.
1618 </description>
1619 </param>
1620 </parameters>
1621 <errors>
1622 </errors>
1623 </function>
1624
1625 <function id="ResumeThread" num="6">
1626 <synopsis>Resume Thread</synopsis>
1627 <description>
1628 Resume a suspended thread.
1629 Any threads currently suspended through
1630 a <jvmti/> suspend function (eg.
1631 <functionlink id="SuspendThread"></functionlink>)
1632 or <code>java.lang.Thread.suspend()</code>
1633 will resume execution;
1634 all other threads are unaffected.
1635 </description>
1636 <origin>jvmdi</origin>
1637 <capabilities>
1638 <required id="can_suspend"></required>
1639 </capabilities>
1640 <parameters>
1641 <param id="thread">
1642 <jthread/>
1643 <description>
1644 The thread to resume.
1645 </description>
1646 </param>
1647 </parameters>
1648 <errors>
1649 <error id="JVMTI_ERROR_THREAD_NOT_SUSPENDED">
1650 Thread was not suspended.
1651 </error>
1652 <error id="JVMTI_ERROR_INVALID_TYPESTATE">
1653 The state of the thread has been modified, and is now inconsistent.
1654 </error>
1655 </errors>
1656 </function>
1657
1658 <function id="ResumeThreadList" num="93">
1659 <synopsis>Resume Thread List</synopsis>
1660 <description>
1661 Resume the <paramlink id="request_count"></paramlink>
1662 threads specified in the
1663 <paramlink id="request_list"></paramlink> array.
1664 Any thread suspended through
1665 a <jvmti/> suspend function (eg.
1666 <functionlink id="SuspendThreadList"></functionlink>)
1667 or <code>java.lang.Thread.suspend()</code>
1668 will resume execution.
1669 </description>
1670 <origin>jvmdi</origin>
1671 <capabilities>
1672 <required id="can_suspend"></required>
1673 </capabilities>
1674 <parameters>
1675 <param id="request_count">
1676 <jint min="0"/>
1677 <description>
1678 The number of threads to resume.
1679 </description>
1680 </param>
1681 <param id="request_list">
1682 <inbuf incount="request_count"><jthread/></inbuf>
1683 <description>
1684 The threads to resume.
1685 </description>
1686 </param>
1687 <param id="results">
1688 <outbuf incount="request_count"><enum>jvmtiError</enum></outbuf>
1689 <description>
1690 An agent supplied array of
1691 <paramlink id="request_count"></paramlink> elements.
1692 On return, filled with the error code for
1693 the resume of the corresponding thread.
1694 The error code will be
1695 <errorlink id="JVMTI_ERROR_NONE"></errorlink>
1696 if the thread was suspended by this call.
1697 Possible error codes are those specified
1698 for <functionlink id="ResumeThread"></functionlink>.
1699 </description>
1700 </param>
1701 </parameters>
1702 <errors>
1703 </errors>
1704 </function>
1705
1706 <function id="StopThread" num="7">
1707 <synopsis>Stop Thread</synopsis>
1708 <description>
1709 Send the specified asynchronous exception to the specified thread
1710 (similar to <code>java.lang.Thread.stop</code>).
1711 Normally, this function is used to kill the specified thread with an
1712 instance of the exception <code>ThreadDeath</code>.
1713 </description>
1714 <origin>jvmdi</origin>
1715 <capabilities>
1716 <required id="can_signal_thread"></required>
1717 </capabilities>
1718 <parameters>
1719 <param id="thread">
1720 <jthread/>
1721 <description>
1722 The thread to stop.
1723 </description>
1724 </param>
1725 <param id="exception">
1726 <jobject/>
1727 <description>
1728 The asynchronous exception object.
1729 </description>
1730 </param>
1731 </parameters>
1732 <errors>
1733 </errors>
1734 </function>
1735
1736 <function id="InterruptThread" num="8">
1737 <synopsis>Interrupt Thread</synopsis>
1738 <description>
1739 Interrupt the specified thread
1740 (similar to <code>java.lang.Thread.interrupt</code>).
1741 </description>
1742 <origin>jvmdi</origin>
1743 <capabilities>
1744 <required id="can_signal_thread"></required>
1745 </capabilities>
1746 <parameters>
1747 <param id="thread">
1748 <jthread impl="noconvert"/>
1749 <description>
1750 The thread to interrupt.
1751 </description>
1752 </param>
1753 </parameters>
1754 <errors>
1755 </errors>
1756 </function>
1757
1758 <function id="GetThreadInfo" num="9">
1759 <synopsis>Get Thread Info</synopsis>
1760 <typedef id="jvmtiThreadInfo" label="Thread information structure">
1761 <field id="name">
1762 <allocfieldbuf><char/></allocfieldbuf>
1763 <description>
1764 The thread name, encoded as a
1765 <internallink id="mUTF">modified UTF-8</internallink> string.
1766 </description>
1767 </field>
1768 <field id="priority">
1769 <jint/>
1770 <description>
1771 The thread priority. See the thread priority constants:
1772 <datalink id="jvmtiThreadPriority"></datalink>.
1773 </description>
1774 </field>
1775 <field id="is_daemon">
1776 <jboolean/>
1777 <description>
1778 Is this a daemon thread?
1779 </description>
1780 </field>
1781 <field id="thread_group">
1782 <jthreadGroup/>
1783 <description>
1784 The thread group to which this thread belongs.
1785 <code>NULL</code> if the thread has died.
1786 </description>
1787 </field>
1788 <field id="context_class_loader">
1789 <jobject/>
1790 <description>
1791 The context class loader associated with this thread.
1792 </description>
1793 </field>
1794 </typedef>
1795 <description>
1796 Get thread information. The fields of the <datalink id="jvmtiThreadInfo"/> structure
1797 are filled in with details of the specified thread.
1798 </description>
1799 <origin>jvmdi</origin>
1800 <capabilities>
1801 </capabilities>
1802 <parameters>
1803 <param id="thread">
1804 <jthread null="current" impl="noconvert" started="maybe"/>
1805 <description>
1806 The thread to query.
1807 </description>
1808 </param>
1809 <param id="info_ptr">
1810 <outptr><struct>jvmtiThreadInfo</struct></outptr>
1811 <description>
1812 On return, filled with information describing the specified thread.
1813 <p/>
1814 For JDK 1.1 implementations that don't
1815 recognize context class loaders,
1816 the <code>context_class_loader</code> field will be NULL.
1817 </description>
1818 </param>
1819 </parameters>
1820 <errors>
1821 </errors>
1822 </function>
1823
1824 <function id="GetOwnedMonitorInfo" num="10">
1825 <synopsis>Get Owned Monitor Info</synopsis>
1826 <description>
1827 Get information about the monitors owned by the
1828 specified thread.
1829 </description>
1830 <origin>jvmdiClone</origin>
1831 <capabilities>
1832 <required id="can_get_owned_monitor_info"></required>
1833 </capabilities>
1834 <parameters>
1835 <param id="thread">
1836 <jthread null="current"/>
1837 <description>
1838 The thread to query.
1839 </description>
1840 </param>
1841 <param id="owned_monitor_count_ptr">
1842 <outptr><jint/></outptr>
1843 <description>
1844 The number of monitors returned.
1845 </description>
1846 </param>
1847 <param id="owned_monitors_ptr">
1848 <allocbuf outcount="owned_monitor_count_ptr"><jobject/></allocbuf>
1849 <description>
1850 The array of owned monitors.
1851 </description>
1852 </param>
1853 </parameters>
1854 <errors>
1855 </errors>
1856 </function>
1857
1858 <function id="GetOwnedMonitorStackDepthInfo" num="153" since="1.1">
1859 <synopsis>Get Owned Monitor Stack Depth Info</synopsis>
1860 <typedef id="jvmtiMonitorStackDepthInfo"
1861 label="Monitor stack depth information structure">
1862 <field id="monitor">
1863 <jobject/>
1864 <description>
1865 The owned monitor.
1866 </description>
1867 </field>
1868 <field id="stack_depth">
1869 <jint/>
1870 <description>
1871 The stack depth. Corresponds to the stack depth used in the
1872 <internallink id="stack">Stack Frame functions</internallink>.
1873 That is, zero is the current frame, one is the frame which
1874 called the current frame. And it is negative one if the
1875 implementation cannot determine the stack depth (e.g., for
1876 monitors acquired by JNI <code>MonitorEnter</code>).
1877 </description>
1878 </field>
1879 </typedef>
1880 <description>
1881 Get information about the monitors owned by the
1882 specified thread and the depth of the stack frame which locked them.
1883 </description>
1884 <origin>new</origin>
1885 <capabilities>
1886 <required id="can_get_owned_monitor_stack_depth_info"></required>
1887 </capabilities>
1888 <parameters>
1889 <param id="thread">
1890 <jthread null="current"/>
1891 <description>
1892 The thread to query.
1893 </description>
1894 </param>
1895 <param id="monitor_info_count_ptr">
1896 <outptr><jint/></outptr>
1897 <description>
1898 The number of monitors returned.
1899 </description>
1900 </param>
1901 <param id="monitor_info_ptr">
1902 <allocbuf outcount="owned_monitor_depth_count_ptr">
1903 <struct>jvmtiMonitorStackDepthInfo</struct>
1904 </allocbuf>
1905 <description>
1906 The array of owned monitor depth information.
1907 </description>
1908 </param>
1909 </parameters>
1910 <errors>
1911 </errors>
1912 </function>
1913
1914 <function id="GetCurrentContendedMonitor" num="11">
1915 <synopsis>Get Current Contended Monitor</synopsis>
1916 <description>
1917 Get the object, if any, whose monitor the specified thread is waiting to
1918 enter or waiting to regain through <code>java.lang.Object.wait</code>.
1919 </description>
1920 <origin>jvmdi</origin>
1921 <capabilities>
1922 <required id="can_get_current_contended_monitor"></required>
1923 </capabilities>
1924 <parameters>
1925 <param id="thread">
1926 <jthread null="current"/>
1927 <description>
1928 The thread to query.
1929 </description>
1930 </param>
1931 <param id="monitor_ptr">
1932 <outptr><jobject/></outptr>
1933 <description>
1934 On return, filled with the current contended monitor, or
1935 NULL if there is none.
1936 </description>
1937 </param>
1938 </parameters>
1939 <errors>
1940 </errors>
1941 </function>
1942
1943 <callback id="jvmtiStartFunction">
1944 <void/>
1945 <synopsis>Agent Start Function</synopsis>
1946 <description>
1947 Agent supplied callback function.
1948 This function is the entry point for an agent thread
1949 started with
1950 <functionlink id="RunAgentThread"></functionlink>.
1951 </description>
1952 <parameters>
1953 <param id="jvmti_env">
1954 <outptr>
1955 <struct>jvmtiEnv</struct>
1956 </outptr>
1957 <description>
1958 The <jvmti/> environment.
1959 </description>
1960 </param>
1961 <param id="jni_env">
1962 <outptr>
1963 <struct>JNIEnv</struct>
1964 </outptr>
1965 <description>
1966 The JNI environment.
1967 </description>
1968 </param>
1969 <param id="arg">
1970 <outptr>
1971 <void/>
1972 </outptr>
1973 <description>
1974 The <code>arg</code> parameter passed to
1975 <functionlink id="RunAgentThread"></functionlink>.
1976 </description>
1977 </param>
1978 </parameters>
1979 </callback>
1980
1981 <function id="RunAgentThread" num="12">
1982 <synopsis>Run Agent Thread</synopsis>
1983 <description>
1984 Starts the execution of an agent thread. with the specified native function.
1985 The parameter <paramlink id="arg"></paramlink> is forwarded on to the
1986 <functionlink id="jvmtiStartFunction">start function</functionlink>
1987 (specified with <paramlink id="proc"></paramlink>) as its single argument.
1988 This function allows the creation of agent threads
1989 for handling communication with another process or for handling events
1990 without the need to load a special subclass of <code>java.lang.Thread</code> or
1991 implementer of <code>java.lang.Runnable</code>.
1992 Instead, the created thread can run entirely in native code.
1993 However, the created thread does require a newly created instance
1994 of <code>java.lang.Thread</code> (referenced by the argument <code>thread</code>) to
1995 which it will be associated.
1996 The thread object can be created with JNI calls.
1997 <p/>
1998 The following common thread priorities are provided for your convenience:
1999 <constants id="jvmtiThreadPriority" label="Thread Priority Constants" kind="const">
2000 <constant id="JVMTI_THREAD_MIN_PRIORITY" num="1">
2001 Minimum possible thread priority
2002 </constant>
2003 <constant id="JVMTI_THREAD_NORM_PRIORITY" num="5">
2004 Normal thread priority
2005 </constant>
2006 <constant id="JVMTI_THREAD_MAX_PRIORITY" num="10">
2007 Maximum possible thread priority
2008 </constant>
2009 </constants>
2010 <p/>
2011 The new thread is started as a daemon thread with the specified
2012 <paramlink id="priority"></paramlink>.
2013 If enabled, a <eventlink id="ThreadStart"/> event will be sent.
2014 <p/>
2015 Since the thread has been started, the thread will be live when this function
2016 returns, unless the thread has died immediately.
2017 <p/>
2018 The thread group of the thread is ignored -- specifically, the thread is not
2019 added to the thread group and the thread is not seen on queries of the thread
2020 group at either the Java programming language or <jvmti/> levels.
2021 <p/>
2022 The thread is not visible to Java programming language queries but is
2023 included in <jvmti/> queries (for example,
2024 <functionlink id="GetAllThreads"/> and
2025 <functionlink id="GetAllStackTraces"/>).
2026 <p/>
2027 Upon execution of <code>proc</code>, the new thread will be attached to the
2028 VM--see the JNI documentation on
2029 <externallink id="http://java.sun.com/javase/6/docs/technotes/guides/jni/spec/invocation.html#wp1060"
2030 >Attaching to the VM</externallink>.
2031 </description>
2032 <origin>jvmdiClone</origin>
2033 <capabilities>
2034 </capabilities>
2035 <parameters>
2036 <param id="thread">
2037 <jthread impl="noconvert" started="no"/>
2038 <description>
2039 The thread to run.
2040 </description>
2041 </param>
2042 <param id="proc">
2043 <ptrtype>
2044 <struct>jvmtiStartFunction</struct>
2045 </ptrtype>
2046 <description>
2047 The start function.
2048 </description>
2049 </param>
2050 <param id="arg">
2051 <inbuf>
2052 <void/>
2053 <nullok><code>NULL</code> is passed to the start function</nullok>
2054 </inbuf>
2055 <description>
2056 The argument to the start function.
2057 </description>
2058 </param>
2059 <param id="priority">
2060 <jint/>
2061 <description>
2062 The priority of the started thread. Any thread
2063 priority allowed by <code>java.lang.Thread.setPriority</code> can be used including
2064 those in <datalink id="jvmtiThreadPriority"></datalink>.
2065 </description>
2066 </param>
2067 </parameters>
2068 <errors>
2069 <error id="JVMTI_ERROR_INVALID_PRIORITY">
2070 <paramlink id="priority"/> is less than
2071 <datalink id="JVMTI_THREAD_MIN_PRIORITY"/>
2072 or greater than
2073 <datalink id="JVMTI_THREAD_MAX_PRIORITY"/>
2074 </error>
2075 </errors>
2076 </function>
2077
2078 <function id="SetThreadLocalStorage" jkernel="yes" impl="notrace" phase="start" num="103">
2079 <synopsis>Set Thread Local Storage</synopsis>
2080 <description>
2081 The VM stores a pointer value associated with each environment-thread
2082 pair. This pointer value is called <i>thread-local storage</i>.
2083 This value is <code>NULL</code> unless set with this function.
2084 Agents can allocate memory in which they store thread specific
2085 information. By setting thread-local storage it can then be
2086 accessed with
2087 <functionlink id="GetThreadLocalStorage"></functionlink>.
2088 <p/>
2089 This function is called by the agent to set the value of the <jvmti/>
2090 thread-local storage. <jvmti/> supplies to the agent a pointer-size
2091 thread-local storage that can be used to record per-thread
2092 information.
2093 </description>
2094 <origin>jvmpi</origin>
2095 <capabilities>
2096 </capabilities>
2097 <parameters>
2098 <param id="thread">
2099 <jthread null="current"/>
2100 <description>
2101 Store to this thread.
2102 </description>
2103 </param>
2104 <param id="data">
2105 <inbuf>
2106 <void/>
2107 <nullok>value is set to <code>NULL</code></nullok>
2108 </inbuf>
2109 <description>
2110 The value to be entered into the thread-local storage.
2111 </description>
2112 </param>
2113 </parameters>
2114 <errors>
2115 </errors>
2116 </function>
2117
2118 <function id="GetThreadLocalStorage" jkernel="yes" impl="innative notrace" phase="start" num="102">
2119 <synopsis>Get Thread Local Storage</synopsis>
2120 <description>
2121 Called by the agent to get the value of the <jvmti/> thread-local
2122 storage.
2123 </description>
2124 <origin>jvmpi</origin>
2125 <capabilities>
2126 </capabilities>
2127 <parameters>
2128 <param id="thread">
2129 <jthread null="current" impl="noconvert"/>
2130 <description>
2131 Retrieve from this thread.
2132 </description>
2133 </param>
2134 <param id="data_ptr">
2135 <agentbuf><void/></agentbuf>
2136 <description>
2137 Pointer through which the value of the thread local
2138 storage is returned.
2139 If thread-local storage has not been set with
2140 <functionlink id="SetThreadLocalStorage"></functionlink> the returned
2141 pointer is <code>NULL</code>.
2142 </description>
2143 </param>
2144 </parameters>
2145 <errors>
2146 </errors>
2147 </function>
2148
2149 </category>
2150
2151 <category id="thread_groups" label="Thread Group">
2152 <intro>
2153 </intro>
2154
2155 <function id="GetTopThreadGroups" num="13">
2156 <synopsis>Get Top Thread Groups</synopsis>
2157 <description>
2158 Return all top-level (parentless) thread groups in the VM.
2159 </description>
2160 <origin>jvmdi</origin>
2161 <capabilities>
2162 </capabilities>
2163 <parameters>
2164 <param id="group_count_ptr">
2165 <outptr><jint/></outptr>
2166 <description>
2167 On return, points to the number of top-level thread groups.
2168 </description>
2169 </param>
2170 <param id="groups_ptr">
2171 <allocbuf outcount="group_count_ptr"><jthreadGroup/></allocbuf>
2172 <description>
2173 On return, refers to a pointer to the top-level thread group array.
2174 </description>
2175 </param>
2176 </parameters>
2177 <errors>
2178 </errors>
2179 </function>
2180
2181 <function id="GetThreadGroupInfo" num="14">
2182 <synopsis>Get Thread Group Info</synopsis>
2183 <typedef id="jvmtiThreadGroupInfo" label="Thread group information structure">
2184 <field id="parent">
2185 <jthreadGroup/>
2186 <description>
2187 The parent thread group.
2188 </description>
2189 </field>
2190 <field id="name">
2191 <allocfieldbuf><char/></allocfieldbuf>
2192 <description>
2193 The thread group's name, encoded as a
2194 <internallink id="mUTF">modified UTF-8</internallink> string.
2195 </description>
2196 </field>
2197 <field id="max_priority">
2198 <jint/>
2199 <description>
2200 The maximum priority for this thread group.
2201 </description>
2202 </field>
2203 <field id="is_daemon">
2204 <jboolean/>
2205 <description>
2206 Is this a daemon thread group?
2207 </description>
2208 </field>
2209 </typedef>
2210 <description>
2211 Get information about the thread group. The fields of the
2212 <functionlink id="jvmtiThreadGroupInfo"></functionlink> structure
2213 are filled in with details of the specified thread group.
2214 </description>
2215 <origin>jvmdi</origin>
2216 <capabilities>
2217 </capabilities>
2218 <parameters>
2219 <param id="group">
2220 <jthreadGroup/>
2221 <description>
2222 The thread group to query.
2223 </description>
2224 </param>
2225 <param id="info_ptr">
2226 <outptr><struct>jvmtiThreadGroupInfo</struct></outptr>
2227 <description>
2228 On return, filled with information describing the specified
2229 thread group.
2230 </description>
2231 </param>
2232 </parameters>
2233 <errors>
2234 </errors>
2235 </function>
2236
2237 <function id="GetThreadGroupChildren" num="15">
2238 <synopsis>Get Thread Group Children</synopsis>
2239 <description>
2240 Get the live threads and active subgroups in this thread group.
2241 </description>
2242 <origin>jvmdi</origin>
2243 <capabilities>
2244 </capabilities>
2245 <parameters>
2246 <param id="group">
2247 <jthreadGroup/>
2248 <description>
2249 The group to query.
2250 </description>
2251 </param>
2252 <param id="thread_count_ptr">
2253 <outptr><jint/></outptr>
2254 <description>
2255 On return, points to the number of live threads in this thread group.
2256 </description>
2257 </param>
2258 <param id="threads_ptr">
2259 <allocbuf outcount="thread_count_ptr"><jthread/></allocbuf>
2260 <description>
2261 On return, points to an array of the live threads in this thread group.
2262 </description>
2263 </param>
2264 <param id="group_count_ptr">
2265 <outptr><jint/></outptr>
2266 <description>
2267 On return, points to the number of active child thread groups
2268 </description>
2269 </param>
2270 <param id="groups_ptr">
2271 <allocbuf outcount="group_count_ptr"><jthreadGroup/></allocbuf>
2272 <description>
2273 On return, points to an array of the active child thread groups.
2274 </description>
2275 </param>
2276 </parameters>
2277 <errors>
2278 </errors>
2279 </function>
2280 </category>
2281
2282 <category id="stack" label="Stack Frame">
2283 <intro>
2284 These functions provide information about the stack of a thread.
2285 Stack frames are referenced by depth.
2286 The frame at depth zero is the current frame.
2287 <p/>
2288 Stack frames are as described in the
2289 <vmspeclink id="Overview.doc.html#17257"
2290 name="Frames section"/>.
2291 That is, they correspond to method
2292 invocations (including native methods) but do not correspond to platform native or
2293 VM internal frames.
2294 <p/>
2295 A <jvmti/> implementation may use method invocations to launch a thread and
2296 the corresponding frames may be included in the stack as presented by these functions --
2297 that is, there may be frames shown
2298 deeper than <code>main()</code> and <code>run()</code>.
2299 However this presentation must be consistent across all <jvmti/> functionality which
2300 uses stack frames or stack depth.
2301 </intro>
2302
2303 <typedef id="jvmtiFrameInfo" label="Stack frame information structure">
2304 <description>
2305 Information about a stack frame is returned in this structure.
2306 </description>
2307 <field id="method">
2308 <jmethodID/>
2309 <description>
2310 The method executing in this frame.
2311 </description>
2312 </field>
2313 <field id="location">
2314 <jlocation/>
2315 <description>
2316 The index of the instruction executing in this frame.
2317 <code>-1</code> if the frame is executing a native method.
2318 </description>
2319 </field>
2320 </typedef>
2321
2322 <typedef id="jvmtiStackInfo" label="Stack information structure">
2323 <description>
2324 Information about a set of stack frames is returned in this structure.
2325 </description>
2326 <field id="thread">
2327 <jthread/>
2328 <description>
2329 On return, the thread traced.
2330 </description>
2331 </field>
2332 <field id="state">
2333 <jint/>
2334 <description>
2335 On return, the thread state. See <functionlink id="GetThreadState"></functionlink>.
2336 </description>
2337 </field>
2338 <field id="frame_buffer">
2339 <outbuf incount="max_frame_count">
2340 <struct>jvmtiFrameInfo</struct>
2341 </outbuf>
2342 <description>
2343 On return, this agent allocated buffer is filled
2344 with stack frame information.
2345 </description>
2346 </field>
2347 <field id="frame_count">
2348 <jint/>
2349 <description>
2350 On return, the number of records filled into
2351 <code>frame_buffer</code>.
2352 This will be
2353 min(<code>max_frame_count</code>, <i>stackDepth</i>).
2354 </description>
2355 </field>
2356 </typedef>
2357
2358 <function id="GetStackTrace" num="104">
2359 <synopsis>Get Stack Trace</synopsis>
2360 <description>
2361 Get information about the stack of a thread.
2362 If <paramlink id="max_frame_count"></paramlink> is less than the depth of the stack,
2363 the <paramlink id="max_frame_count"></paramlink> topmost frames are returned,
2364 otherwise the entire stack is returned.
2365 The topmost frames, those most recently invoked, are at the beginning of the returned buffer.
2366 <p/>
2367 The following example causes up to five of the topmost frames
2368 to be returned and (if there are any frames) the currently
2369 executing method name to be printed.
2370 <example>
2371 jvmtiFrameInfo frames[5];
2372 jint count;
2373 jvmtiError err;
2374
2375 err = (*jvmti)-&gt;GetStackTrace(jvmti, aThread, 0, 5,
2376 &amp;frames, &amp;count);
2377 if (err == JVMTI_ERROR_NONE &amp;&amp; count &gt;= 1) {
2378 char *methodName;
2379 err = (*jvmti)-&gt;GetMethodName(jvmti, frames[0].method,
2380 &amp;methodName, NULL);
2381 if (err == JVMTI_ERROR_NONE) {
2382 printf("Executing method: %s", methodName);
2383 }
2384 }
2385 </example>
2386 <todo>
2387 check example code.
2388 </todo>
2389 <p/>
2390 The <paramlink id="thread"></paramlink> need not be suspended
2391 to call this function.
2392 <p/>
2393 The <functionlink id="GetLineNumberTable"></functionlink>
2394 function can be used to map locations to line numbers. Note that
2395 this mapping can be done lazily.
2396 </description>
2397 <origin>jvmpi</origin>
2398 <capabilities>
2399 </capabilities>
2400 <parameters>
2401 <param id="thread">
2402 <jthread null="current"/>
2403 <description>
2404 Fetch the stack trace of this thread.
2405 </description>
2406 </param>
2407 <param id="start_depth">
2408 <jint/>
2409 <description>
2410 Begin retrieving frames at this depth.
2411 If non-negative, count from the current frame,
2412 the first frame retrieved is at depth <code>start_depth</code>.
2413 For example, if zero, start from the current frame; if one, start from the
2414 caller of the current frame; if two, start from the caller of the
2415 caller of the current frame; and so on.
2416 If negative, count from below the oldest frame,
2417 the first frame retrieved is at depth <i>stackDepth</i><code> + start_depth</code>,
2418 where <i>stackDepth</i> is the count of frames on the stack.
2419 For example, if negative one, only the oldest frame is retrieved;
2420 if negative two, start from the frame called by the oldest frame.
2421 </description>
2422 </param>
2423 <param id="max_frame_count">
2424 <jint min="0"/>
2425 <description>
2426 The maximum number of <datalink id="jvmtiFrameInfo"/> records to retrieve.
2427 </description>
2428 </param>
2429 <param id="frame_buffer">
2430 <outbuf incount="max_frame_count" outcount="count_ptr">
2431 <struct>jvmtiFrameInfo</struct>
2432 </outbuf>
2433 <description>
2434 On return, this agent allocated buffer is filled
2435 with stack frame information.
2436 </description>
2437 </param>
2438 <param id="count_ptr">
2439 <outptr><jint/></outptr>
2440 <description>
2441 On return, points to the number of records filled in.
2442 For non-negative <code>start_depth</code>, this will be
2443 min(<code>max_frame_count</code>, <i>stackDepth</i><code> - start_depth</code>).
2444 For negative <code>start_depth</code>, this will be
2445 min(<code>max_frame_count</code>, <code>-start_depth</code>).
2446 </description>
2447 </param>
2448 </parameters>
2449 <errors>
2450 <error id="JVMTI_ERROR_ILLEGAL_ARGUMENT">
2451 <paramlink id="start_depth"/> is positive and greater than or equal to <i>stackDepth</i>.
2452 Or <paramlink id="start_depth"/> is negative and less than <i>-stackDepth</i>.
2453 </error>
2454 </errors>
2455 </function>
2456
2457
2458 <function id="GetAllStackTraces" num="100">
2459 <synopsis>Get All Stack Traces</synopsis>
2460 <description>
2461 Get information about the stacks of all live threads
2462 (including <internallink id="RunAgentThread">agent threads</internallink>).
2463 If <paramlink id="max_frame_count"/> is less than the depth of a stack,
2464 the <paramlink id="max_frame_count"/> topmost frames are returned for that thread,
2465 otherwise the entire stack is returned.
2466 The topmost frames, those most recently invoked, are at the beginning of the returned buffer.
2467 <p/>
2468 All stacks are collected simultaneously, that is, no changes will occur to the
2469 thread state or stacks between the sampling of one thread and the next.
2470 The threads need not be suspended.
2471
2472 <example>
2473 jvmtiStackInfo *stack_info;
2474 jint thread_count;
2475 int ti;
2476 jvmtiError err;
2477
2478 err = (*jvmti)-&gt;GetAllStackTraces(jvmti, MAX_FRAMES, &amp;stack_info, &amp;thread_count);
2479 if (err != JVMTI_ERROR_NONE) {
2480 ...
2481 }
2482 for (ti = 0; ti &lt; thread_count; ++ti) {
2483 jvmtiStackInfo *infop = &amp;stack_info[ti];
2484 jthread thread = infop-&gt;thread;
2485 jint state = infop-&gt;state;
2486 jvmtiFrameInfo *frames = infop-&gt;frame_buffer;
2487 int fi;
2488
2489 myThreadAndStatePrinter(thread, state);
2490 for (fi = 0; fi &lt; infop-&gt;frame_count; fi++) {
2491 myFramePrinter(frames[fi].method, frames[fi].location);
2492 }
2493 }
2494 /* this one Deallocate call frees all data allocated by GetAllStackTraces */
2495 err = (*jvmti)-&gt;Deallocate(jvmti, stack_info);
2496 </example>
2497 <todo>
2498 check example code.
2499 </todo>
2500
2501 </description>
2502 <origin>new</origin>
2503 <capabilities>
2504 </capabilities>
2505 <parameters>
2506 <param id="max_frame_count">
2507 <jint min="0"/>
2508 <description>
2509 The maximum number of <datalink id="jvmtiFrameInfo"/> records to retrieve per thread.
2510 </description>
2511 </param>
2512 <param id="stack_info_ptr">
2513 <allocbuf>
2514 <struct>jvmtiStackInfo</struct>
2515 </allocbuf>
2516 <description>
2517 On return, this buffer is filled
2518 with stack information for each thread.
2519 The number of <datalink id="jvmtiStackInfo"/> records is determined
2520 by <paramlink id="thread_count_ptr"/>.
2521 <p/>
2522 Note that this buffer is allocated to include the <datalink id="jvmtiFrameInfo"/>
2523 buffers pointed to by <datalink id="jvmtiStackInfo.frame_buffer"/>.
2524 These buffers must not be separately deallocated.
2525 </description>
2526 </param>
2527 <param id="thread_count_ptr">
2528 <outptr><jint/></outptr>
2529 <description>
2530 The number of threads traced.
2531 </description>
2532 </param>
2533 </parameters>
2534 <errors>
2535 </errors>
2536 </function>
2537
2538 <function id="GetThreadListStackTraces" num="101">
2539 <synopsis>Get Thread List Stack Traces</synopsis>
2540 <description>
2541 Get information about the stacks of the supplied threads.
2542 If <paramlink id="max_frame_count"/> is less than the depth of a stack,
2543 the <paramlink id="max_frame_count"/> topmost frames are returned for that thread,
2544 otherwise the entire stack is returned.
2545 The topmost frames, those most recently invoked, are at the beginning of the returned buffer.
2546 <p/>
2547 All stacks are collected simultaneously, that is, no changes will occur to the
2548 thread state or stacks between the sampling one thread and the next.
2549 The threads need not be suspended.
2550 <p/>
2551 If a thread has not yet started or terminates before the stack information is collected,
2552 a zero length stack (<datalink id="jvmtiStackInfo.frame_count"/> will be zero)
2553 will be returned and the thread <datalink id="jvmtiStackInfo.state"/> can be checked.
2554 <p/>
2555 See the example for the similar function
2556 <functionlink id="GetAllStackTraces"/>.
2557 </description>
2558 <origin>new</origin>
2559 <capabilities>
2560 </capabilities>
2561 <parameters>
2562 <param id="thread_count">
2563 <jint min="0"/>
2564 <description>
2565 The number of threads to trace.
2566 </description>
2567 </param>
2568 <param id="thread_list">
2569 <inbuf incount="thread_count"><jthread/></inbuf>
2570 <description>
2571 The list of threads to trace.
2572 </description>
2573 </param>
2574 <param id="max_frame_count">
2575 <jint min="0"/>
2576 <description>
2577 The maximum number of <datalink id="jvmtiFrameInfo"/> records to retrieve per thread.
2578 </description>
2579 </param>
2580 <param id="stack_info_ptr">
2581 <allocbuf outcount="thread_count">
2582 <struct>jvmtiStackInfo</struct>
2583 </allocbuf>
2584 <description>
2585 On return, this buffer is filled
2586 with stack information for each thread.
2587 The number of <datalink id="jvmtiStackInfo"/> records is determined
2588 by <paramlink id="thread_count"/>.
2589 <p/>
2590 Note that this buffer is allocated to include the <datalink id="jvmtiFrameInfo"/>
2591 buffers pointed to by <datalink id="jvmtiStackInfo.frame_buffer"/>.
2592 These buffers must not be separately deallocated.
2593 </description>
2594 </param>
2595 </parameters>
2596 <errors>
2597 <error id="JVMTI_ERROR_INVALID_THREAD">
2598 An element in <paramlink id="thread_list"/> is not a thread object.
2599 </error>
2600 </errors>
2601 </function>
2602
2603 <elide>
2604 <function id="AsyncGetStackTrace" num="1000">
2605 <synopsis>Get Stack Trace--Asynchronous</synopsis>
2606 <description>
2607 Get information about the entire stack of a thread (or a sub-section of it).
2608 This is the asynchronous version of <functionlink id="GetStackTrace"></functionlink>
2609 and is reentrant and safe to call
2610 from asynchronous signal handlers.
2611 The stack trace is returned only for the calling thread.
2612 <p/>
2613 The <functionlink id="GetLineNumberTable"></functionlink>
2614 function can be used to map locations to line numbers. Note that
2615 this mapping can be done lazily.
2616 </description>
2617 <origin>jvmpi</origin>
2618 <capabilities>
2619 <required id="can_get_async_stack_trace"></required>
2620 <capability id="can_show_JVM_spec_async_frames">
2621 If <code>false</code>,
2622 <paramlink id="use_java_stack"></paramlink>
2623 must be <code>false</code>.
2624 </capability>
2625 </capabilities>
2626 <parameters>
2627 <param id="use_java_stack">
2628 <jboolean/>
2629 <description>
2630 Return the stack showing the <vmspeclink/>
2631 model of the stack;
2632 otherwise, show the internal representation of the stack with
2633 inlined and optimized methods missing. If the virtual machine
2634 is using the <i>Java Virtual Machine Specification</i> stack model
2635 internally, this flag is ignored.
2636 </description>
2637 </param>
2638 <param id="max_count">
2639 <jint min="0"/>
2640 <description>
2641 The maximum number of <datalink id="jvmtiFrameInfo"/> records to retrieve.
2642 Retrieve this many unless the stack depth is less than <code>max_count</code>.
2643 </description>
2644 </param>
2645 <param id="frame_buffer">
2646 <outbuf incount="max_count" outcount="count_ptr">
2647 <struct>jvmtiFrameInfo</struct>
2648 <nullok>this information is not returned</nullok>
2649 </outbuf>
2650 <description>
2651 The agent passes in a buffer
2652 large enough to hold <code>max_count</code> records of
2653 <datalink id="jvmtiFrameInfo"></datalink>. This buffer must be
2654 pre-allocated by the agent.
2655 </description>
2656 </param>
2657 <param id="count_ptr">
2658 <outptr><jint/></outptr>
2659 <description>
2660 On return, points to the number of records filled in..
2661 </description>
2662 </param>
2663 </parameters>
2664 <errors>
2665 <error id="JVMTI_ERROR_UNATTACHED_THREAD">
2666 The thread being used to call this function is not attached
2667 to the virtual machine. Calls must be made from attached threads.
2668 </error>
2669 </errors>
2670 </function>
2671 </elide>
2672
2673 <function id="GetFrameCount" num="16">
2674 <synopsis>Get Frame Count</synopsis>
2675 <description>
2676 Get the number of frames currently in the specified thread's call stack.
2677 <p/>
2678 If this function is called for a thread actively executing bytecodes (for example,
2679 not the current thread and not suspended), the information returned is transient.
2680 </description>
2681 <origin>jvmdi</origin>
2682 <capabilities>
2683 </capabilities>
2684 <parameters>
2685 <param id="thread">
2686 <jthread null="current"/>
2687 <description>
2688 The thread to query.
2689 </description>
2690 </param>
2691 <param id="count_ptr">
2692 <outptr><jint/></outptr>
2693 <description>
2694 On return, points to the number of frames in the call stack.
2695 </description>
2696 </param>
2697 </parameters>
2698 <errors>
2699 </errors>
2700 </function>
2701
2702 <function id="PopFrame" num="80">
2703 <synopsis>Pop Frame</synopsis>
2704 <description>
2705 Pop the current frame of <code>thread</code>'s stack.
2706 Popping a frame takes you to the previous frame.
2707 When the thread is resumed, the execution
2708 state of the thread is reset to the state
2709 immediately before the called method was invoked.
2710 That is (using the <vmspeclink/> terminology):
2711 <ul>
2712 <li>the current frame is discarded as the previous frame becomes the current one</li>
2713 <li>the operand stack is restored--the argument values are added back
2714 and if the invoke was not <code>invokestatic</code>,
2715 <code>objectref</code> is added back as well</li>
2716 <li>the Java virtual machine PC is restored to the opcode
2717 of the invoke instruction</li>
2718 </ul>
2719 Note however, that any changes to the arguments, which
2720 occurred in the called method, remain;
2721 when execution continues, the first instruction to
2722 execute will be the invoke.
2723 <p/>
2724 Between calling <code>PopFrame</code> and resuming the
2725 thread the state of the stack is undefined.
2726 To pop frames beyond the first,
2727 these three steps must be repeated:
2728 <ul>
2729 <li>suspend the thread via an event (step, breakpoint, ...)</li>
2730 <li>call <code>PopFrame</code></li>
2731 <li>resume the thread</li>
2732 </ul>
2733 <p/>
2734 A lock acquired by calling the called method
2735 (if it is a <code>synchronized</code> method)
2736 and locks acquired by entering <code>synchronized</code>
2737 blocks within the called method are released.
2738 Note: this does not apply to native locks or
2739 <code>java.util.concurrent.locks</code> locks.
2740 <p/>
2741 Finally blocks are not executed.
2742 <p/>
2743 Changes to global state are not addressed and thus remain changed.
2744 <p/>
2745 The specified thread must be suspended (which implies it cannot be the current thread).
2746 <p/>
2747 Both the called method and calling method must be non-native Java programming
2748 language methods.
2749 <p/>
2750 No <jvmti/> events are generated by this function.
2751 </description>
2752 <origin>jvmdi</origin>
2753 <capabilities>
2754 <required id="can_pop_frame"></required>
2755 </capabilities>
2756 <parameters>
2757 <param id="thread">
2758 <jthread/>
2759 <description>
2760 The thread whose current frame is to be popped.
2761 </description>
2762 </param>
2763 </parameters>
2764 <errors>
2765 <error id="JVMTI_ERROR_OPAQUE_FRAME">
2766 Called or calling method is a native method.
2767 The implementation is unable to pop this frame.
2768 </error>
2769 <error id="JVMTI_ERROR_THREAD_NOT_SUSPENDED">
2770 Thread was not suspended.
2771 </error>
2772 <error id="JVMTI_ERROR_NO_MORE_FRAMES">
2773 There are less than two stack frames on the call stack.
2774 </error>
2775 </errors>
2776 </function>
2777
2778 <function id="GetFrameLocation" num="19">
2779 <synopsis>Get Frame Location</synopsis>
2780 <description>
2781 <p/>
2782 For a Java programming language frame, return the location of the instruction
2783 currently executing.
2784 </description>
2785 <origin>jvmdiClone</origin>
2786 <capabilities>
2787 </capabilities>
2788 <parameters>
2789 <param id="thread">
2790 <jthread null="current" frame="frame"/>
2791 <description>
2792 The thread of the frame to query.
2793 </description>
2794 </param>
2795 <param id="depth">
2796 <jframeID thread="thread"/>
2797 <description>
2798 The depth of the frame to query.
2799 </description>
2800 </param>
2801 <param id="method_ptr">
2802 <outptr><jmethodID/></outptr>
2803 <description>
2804 On return, points to the method for the current location.
2805 </description>
2806 </param>
2807 <param id="location_ptr">
2808 <outptr><jlocation/></outptr>
2809 <description>
2810 On return, points to the index of the currently
2811 executing instruction.
2812 Is set to <code>-1</code> if the frame is executing
2813 a native method.
2814 </description>
2815 </param>
2816 </parameters>
2817 <errors>
2818 </errors>
2819 </function>
2820
2821 <function id="NotifyFramePop" num="20">
2822 <synopsis>Notify Frame Pop</synopsis>
2823 <description>
2824 When the frame that is currently at <paramlink id="depth"></paramlink>
2825 is popped from the stack, generate a
2826 <eventlink id="FramePop"></eventlink> event. See the
2827 <eventlink id="FramePop"></eventlink> event for details.
2828 Only frames corresponding to non-native Java programming language
2829 methods can receive notification.
2830 <p/>
2831 The specified thread must either be the current thread
2832 or the thread must be suspended.
2833 </description>
2834 <origin>jvmdi</origin>
2835 <capabilities>
2836 <required id="can_generate_frame_pop_events"></required>
2837 </capabilities>
2838 <parameters>
2839 <param id="thread">
2840 <jthread null="current" frame="depth"/>
2841 <description>
2842 The thread of the frame for which the frame pop event will be generated.
2843 </description>
2844 </param>
2845 <param id="depth">
2846 <jframeID thread="thread"/>
2847 <description>
2848 The depth of the frame for which the frame pop event will be generated.
2849 </description>
2850 </param>
2851 </parameters>
2852 <errors>
2853 <error id="JVMTI_ERROR_OPAQUE_FRAME">
2854 The frame at <code>depth</code> is executing a
2855 native method.
2856 </error>
2857 <error id="JVMTI_ERROR_THREAD_NOT_SUSPENDED">
2858 Thread was not suspended and was not the current thread.
2859 </error>
2860 </errors>
2861 </function>
2862
2863 </category>
2864
2865 <category id="ForceEarlyReturn" label="Force Early Return">
2866 <intro>
2867 These functions allow an agent to force a method
2868 to return at any point during its execution.
2869 The method which will return early is referred to as the <i>called method</i>.
2870 The called method is the current method
2871 (as defined by the
2872 <vmspeclink id="Overview.doc.html#17257"
2873 name="Frames section"/>)
2874 for the specified thread at
2875 the time the function is called.
2876 <p/>
2877 The specified thread must be suspended or must be the current thread.
2878 The return occurs when execution of Java programming
2879 language code is resumed on this thread.
2880 Between calling one of these functions and resumption
2881 of thread execution, the state of the stack is undefined.
2882 <p/>
2883 No further instructions are executed in the called method.
2884 Specifically, finally blocks are not executed.
2885 Note: this can cause inconsistent states in the application.
2886 <p/>
2887 A lock acquired by calling the called method
2888 (if it is a <code>synchronized</code> method)
2889 and locks acquired by entering <code>synchronized</code>
2890 blocks within the called method are released.
2891 Note: this does not apply to native locks or
2892 <code>java.util.concurrent.locks</code> locks.
2893 <p/>
2894 Events, such as <eventlink id="MethodExit"></eventlink>,
2895 are generated as they would be in a normal return.
2896 <p/>
2897 The called method must be a non-native Java programming
2898 language method.
2899 Forcing return on a thread with only one frame on the
2900 stack causes the thread to exit when resumed.
2901 </intro>
2902
2903 <function id="ForceEarlyReturnObject" num="81" since="1.1">
2904 <synopsis>Force Early Return - Object</synopsis>
2905 <description>
2906 This function can be used to return from a method whose
2907 result type is <code>Object</code>
2908 or a subclass of <code>Object</code>.
2909 </description>
2910 <origin>new</origin>
2911 <capabilities>
2912 <required id="can_force_early_return"></required>
2913 </capabilities>
2914 <parameters>
2915 <param id="thread">
2916 <jthread null="current"/>
2917 <description>
2918 The thread whose current frame is to return early.
2919 </description>
2920 </param>
2921 <param id="value">
2922 <jobject/>
2923 <description>
2924 The return value for the called frame.
2925 An object or <code>NULL</code>.
2926 </description>
2927 </param>
2928 </parameters>
2929 <errors>
2930 <error id="JVMTI_ERROR_OPAQUE_FRAME">
2931 Attempted to return early from a frame
2932 corresponding to a native method.
2933 Or the implementation is unable to provide
2934 this functionality on this frame.
2935 </error>
2936 <error id="JVMTI_ERROR_TYPE_MISMATCH">
2937 The result type of the called method is not
2938 <code>Object</code> or a subclass of <code>Object</code>.
2939 </error>
2940 <error id="JVMTI_ERROR_TYPE_MISMATCH">
2941 The supplied <paramlink id="value"/> is not compatible with the
2942 result type of the called method.
2943 </error>
2944 <error id="JVMTI_ERROR_THREAD_NOT_SUSPENDED">
2945 Thread was not the current thread and was not suspended.
2946 </error>
2947 <error id="JVMTI_ERROR_NO_MORE_FRAMES">
2948 There are no more frames on the call stack.
2949 </error>
2950 </errors>
2951 </function>
2952
2953 <function id="ForceEarlyReturnInt" num="82" since="1.1">
2954 <synopsis>Force Early Return - Int</synopsis>
2955 <description>
2956 This function can be used to return from a method whose
2957 result type is <code>int</code>, <code>short</code>,
2958 <code>char</code>, <code>byte</code>, or
2959 <code>boolean</code>.
2960 </description>
2961 <origin>new</origin>
2962 <capabilities>
2963 <required id="can_force_early_return"></required>
2964 </capabilities>
2965 <parameters>
2966 <param id="thread">
2967 <jthread null="current"/>
2968 <description>
2969 The thread whose current frame is to return early.
2970 </description>
2971 </param>
2972 <param id="value">
2973 <jint/>
2974 <description>
2975 The return value for the called frame.
2976 </description>
2977 </param>
2978 </parameters>
2979 <errors>
2980 <error id="JVMTI_ERROR_OPAQUE_FRAME">
2981 Attempted to return early from a frame
2982 corresponding to a native method.
2983 Or the implementation is unable to provide
2984 this functionality on this frame.
2985 </error>
2986 <error id="JVMTI_ERROR_TYPE_MISMATCH">
2987 The result type of the called method is not
2988 <code>int</code>, <code>short</code>,
2989 <code>char</code>, <code>byte</code>, or
2990 <code>boolean</code>.
2991 </error>
2992 <error id="JVMTI_ERROR_THREAD_NOT_SUSPENDED">
2993 Thread was not the current thread and was not suspended.
2994 </error>
2995 <error id="JVMTI_ERROR_NO_MORE_FRAMES">
2996 There are no frames on the call stack.
2997 </error>
2998 </errors>
2999 </function>
3000
3001 <function id="ForceEarlyReturnLong" num="83" since="1.1">
3002 <synopsis>Force Early Return - Long</synopsis>
3003 <description>
3004 This function can be used to return from a method whose
3005 result type is <code>long</code>.
3006 </description>
3007 <origin>new</origin>
3008 <capabilities>
3009 <required id="can_force_early_return"></required>
3010 </capabilities>
3011 <parameters>
3012 <param id="thread">
3013 <jthread null="current"/>
3014 <description>
3015 The thread whose current frame is to return early.
3016 </description>
3017 </param>
3018 <param id="value">
3019 <jlong/>
3020 <description>
3021 The return value for the called frame.
3022 </description>
3023 </param>
3024 </parameters>
3025 <errors>
3026 <error id="JVMTI_ERROR_OPAQUE_FRAME">
3027 Attempted to return early from a frame
3028 corresponding to a native method.
3029 Or the implementation is unable to provide
3030 this functionality on this frame.
3031 </error>
3032 <error id="JVMTI_ERROR_TYPE_MISMATCH">
3033 The result type of the called method is not <code>long</code>.
3034 </error>
3035 <error id="JVMTI_ERROR_THREAD_NOT_SUSPENDED">
3036 Thread was not the current thread and was not suspended.
3037 </error>
3038 <error id="JVMTI_ERROR_NO_MORE_FRAMES">
3039 There are no frames on the call stack.
3040 </error>
3041 </errors>
3042 </function>
3043
3044 <function id="ForceEarlyReturnFloat" num="84" since="1.1">
3045 <synopsis>Force Early Return - Float</synopsis>
3046 <description>
3047 This function can be used to return from a method whose
3048 result type is <code>float</code>.
3049 </description>
3050 <origin>new</origin>
3051 <capabilities>
3052 <required id="can_force_early_return"></required>
3053 </capabilities>
3054 <parameters>
3055 <param id="thread">
3056 <jthread null="current"/>
3057 <description>
3058 The thread whose current frame is to return early.
3059 </description>
3060 </param>
3061 <param id="value">
3062 <jfloat/>
3063 <description>
3064 The return value for the called frame.
3065 </description>
3066 </param>
3067 </parameters>
3068 <errors>
3069 <error id="JVMTI_ERROR_OPAQUE_FRAME">
3070 Attempted to return early from a frame
3071 corresponding to a native method.
3072 Or the implementation is unable to provide
3073 this functionality on this frame.
3074 </error>
3075 <error id="JVMTI_ERROR_TYPE_MISMATCH">
3076 The result type of the called method is not <code>float</code>.
3077 </error>
3078 <error id="JVMTI_ERROR_THREAD_NOT_SUSPENDED">
3079 Thread was not the current thread and was not suspended.
3080 </error>
3081 <error id="JVMTI_ERROR_NO_MORE_FRAMES">
3082 There are no frames on the call stack.
3083 </error>
3084 </errors>
3085 </function>
3086
3087 <function id="ForceEarlyReturnDouble" num="85" since="1.1">
3088 <synopsis>Force Early Return - Double</synopsis>
3089 <description>
3090 This function can be used to return from a method whose
3091 result type is <code>double</code>.
3092 </description>
3093 <origin>new</origin>
3094 <capabilities>
3095 <required id="can_force_early_return"></required>
3096 </capabilities>
3097 <parameters>
3098 <param id="thread">
3099 <jthread null="current"/>
3100 <description>
3101 The thread whose current frame is to return early.
3102 </description>
3103 </param>
3104 <param id="value">
3105 <jdouble/>
3106 <description>
3107 The return value for the called frame.
3108 </description>
3109 </param>
3110 </parameters>
3111 <errors>
3112 <error id="JVMTI_ERROR_OPAQUE_FRAME">
3113 Attempted to return early from a frame corresponding to a native method.
3114 Or the implementation is unable to provide this functionality on this frame.
3115 </error>
3116 <error id="JVMTI_ERROR_TYPE_MISMATCH">
3117 The result type of the called method is not <code>double</code>.
3118 </error>
3119 <error id="JVMTI_ERROR_THREAD_NOT_SUSPENDED">
3120 Thread was not the current thread and was not suspended.
3121 </error>
3122 <error id="JVMTI_ERROR_NO_MORE_FRAMES">
3123 There are no frames on the call stack.
3124 </error>
3125 </errors>
3126 </function>
3127
3128 <function id="ForceEarlyReturnVoid" num="86" since="1.1">
3129 <synopsis>Force Early Return - Void</synopsis>
3130 <description>
3131 This function can be used to return from a method with no result type.
3132 That is, the called method must be declared <code>void</code>.
3133 </description>
3134 <origin>new</origin>
3135 <capabilities>
3136 <required id="can_force_early_return"></required>
3137 </capabilities>
3138 <parameters>
3139 <param id="thread">
3140 <jthread null="current"/>
3141 <description>
3142 The thread whose current frame is to return early.
3143 </description>
3144 </param>
3145 </parameters>
3146 <errors>
3147 <error id="JVMTI_ERROR_OPAQUE_FRAME">
3148 Attempted to return early from a frame
3149 corresponding to a native method.
3150 Or the implementation is unable to provide
3151 this functionality on this frame.
3152 </error>
3153 <error id="JVMTI_ERROR_TYPE_MISMATCH">
3154 The called method has a result type.
3155 </error>
3156 <error id="JVMTI_ERROR_THREAD_NOT_SUSPENDED">
3157 Thread was not the current thread and was not suspended.
3158 </error>
3159 <error id="JVMTI_ERROR_NO_MORE_FRAMES">
3160 There are no frames on the call stack.
3161 </error>
3162 </errors>
3163 </function>
3164
3165 </category>
3166
3167 <category id="Heap" label="Heap">
3168 <intro>
3169 These functions are used to analyze the heap.
3170 Functionality includes the ability to view the objects in the
3171 heap and to tag these objects.
3172 </intro>
3173
3174 <intro id="objectTags" label="Object Tags">
3175 A <i>tag</i> is a value associated with an object.
3176 Tags are explicitly set by the agent using the
3177 <functionlink id="SetTag"></functionlink> function or by
3178 callback functions such as <functionlink id="jvmtiHeapIterationCallback"/>.
3179 <p/>
3180 Tags are local to the environment; that is, the tags of one
3181 environment are not visible in another.
3182 <p/>
3183 Tags are <code>jlong</code> values which can be used
3184 simply to mark an object or to store a pointer to more detailed
3185 information. Objects which have not been tagged have a
3186 tag of zero.
3187 Setting a tag to zero makes the object untagged.
3188 </intro>
3189
3190 <intro id="heapCallbacks" label="Heap Callback Functions">
3191 Heap functions which iterate through the heap and recursively
3192 follow object references use agent supplied callback functions
3193 to deliver the information.
3194 <p/>
3195 These heap callback functions must adhere to the following restrictions --
3196 These callbacks must not use JNI functions.
3197 These callbacks must not use <jvmti/> functions except
3198 <i>callback safe</i> functions which
3199 specifically allow such use (see the raw monitor, memory management,
3200 and environment local storage functions).
3201 <p/>
3202 An implementation may invoke a callback on an internal thread or
3203 the thread which called the iteration function.
3204 Heap callbacks are single threaded -- no more than one callback will
3205 be invoked at a time.
3206 <p/>
3207 The Heap Filter Flags can be used to prevent reporting
3208 based on the tag status of an object or its class.
3209 If no flags are set (the <code>jint</code> is zero), objects
3210 will not be filtered out.
3211
3212 <constants id="jvmtiHeapFilter" label="Heap Filter Flags" kind="bits">
3213 <constant id="JVMTI_HEAP_FILTER_TAGGED" num="0x4">
3214 Filter out tagged objects. Objects which are tagged are not included.
3215 </constant>
3216 <constant id="JVMTI_HEAP_FILTER_UNTAGGED" num="0x8">
3217 Filter out untagged objects. Objects which are not tagged are not included.
3218 </constant>
3219 <constant id="JVMTI_HEAP_FILTER_CLASS_TAGGED" num="0x10">
3220 Filter out objects with tagged classes. Objects whose class is tagged are not included.
3221 </constant>
3222 <constant id="JVMTI_HEAP_FILTER_CLASS_UNTAGGED" num="0x20">
3223 Filter out objects with untagged classes. Objects whose class is not tagged are not included.
3224 </constant>
3225 </constants>
3226
3227 <p/>
3228 The Heap Visit Control Flags are returned by the heap callbacks
3229 and can be used to abort the iteration. For the
3230 <functionlink id="jvmtiHeapReferenceCallback">Heap
3231 Reference Callback</functionlink>, it can also be used
3232 to prune the graph of traversed references
3233 (<code>JVMTI_VISIT_OBJECTS</code> is not set).
3234
3235 <constants id="jvmtiHeapVisitControl"
3236 label="Heap Visit Control Flags"
3237 kind="bits"
3238 since="1.1">
3239 <constant id="JVMTI_VISIT_OBJECTS" num="0x100">
3240 If we are visiting an object and if this callback
3241 was initiated by <functionlink id="FollowReferences"/>,
3242 traverse the references of this object.
3243 Otherwise ignored.
3244 </constant>
3245 <constant id="JVMTI_VISIT_ABORT" num="0x8000">
3246 Abort the iteration. Ignore all other bits.
3247 </constant>
3248 </constants>
3249
3250 <p/>
3251 The Heap Reference Enumeration is provided by the
3252 <functionlink id="jvmtiHeapReferenceCallback">Heap
3253 Reference Callback</functionlink> and
3254 <functionlink id="jvmtiPrimitiveFieldCallback">Primitive Field
3255 Callback</functionlink> to
3256 describe the kind of reference
3257 being reported.
3258
3259 <constants id="jvmtiHeapReferenceKind"
3260 label="Heap Reference Enumeration"
3261 kind="enum"
3262 since="1.1">
3263 <constant id="JVMTI_HEAP_REFERENCE_CLASS" num="1">
3264 Reference from an object to its class.
3265 </constant>
3266 <constant id="JVMTI_HEAP_REFERENCE_FIELD" num="2">
3267 Reference from an object to the value of one of its instance fields.
3268 </constant>
3269 <constant id="JVMTI_HEAP_REFERENCE_ARRAY_ELEMENT" num="3">
3270 Reference from an array to one of its elements.
3271 </constant>
3272 <constant id="JVMTI_HEAP_REFERENCE_CLASS_LOADER" num="4">
3273 Reference from a class to its class loader.
3274 </constant>
3275 <constant id="JVMTI_HEAP_REFERENCE_SIGNERS" num="5">
3276 Reference from a class to its signers array.
3277 </constant>
3278 <constant id="JVMTI_HEAP_REFERENCE_PROTECTION_DOMAIN" num="6">
3279 Reference from a class to its protection domain.
3280 </constant>
3281 <constant id="JVMTI_HEAP_REFERENCE_INTERFACE" num="7">
3282 Reference from a class to one of its interfaces.
3283 Note: interfaces are defined via a constant pool reference,
3284 so the referenced interfaces may also be reported with a
3285 <code>JVMTI_HEAP_REFERENCE_CONSTANT_POOL</code> reference kind.
3286 </constant>
3287 <constant id="JVMTI_HEAP_REFERENCE_STATIC_FIELD" num="8">
3288 Reference from a class to the value of one of its static fields.
3289 </constant>
3290 <constant id="JVMTI_HEAP_REFERENCE_CONSTANT_POOL" num="9">
3291 Reference from a class to a resolved entry in the constant pool.
3292 </constant>
3293 <constant id="JVMTI_HEAP_REFERENCE_SUPERCLASS" num="10">
3294 Reference from a class to its superclass.
3295 A callback is bot sent if the superclass is <code>java.lang.Object</code>.
3296 Note: loaded classes define superclasses via a constant pool
3297 reference, so the referenced superclass may also be reported with
3298 a <code>JVMTI_HEAP_REFERENCE_CONSTANT_POOL</code> reference kind.
3299 </constant>
3300 <constant id="JVMTI_HEAP_REFERENCE_JNI_GLOBAL" num="21">
3301 Heap root reference: JNI global reference.
3302 </constant>
3303 <constant id="JVMTI_HEAP_REFERENCE_SYSTEM_CLASS" num="22">
3304 Heap root reference: System class.
3305 </constant>
3306 <constant id="JVMTI_HEAP_REFERENCE_MONITOR" num="23">
3307 Heap root reference: monitor.
3308 </constant>
3309 <constant id="JVMTI_HEAP_REFERENCE_STACK_LOCAL" num="24">
3310 Heap root reference: local variable on the stack.
3311 </constant>
3312 <constant id="JVMTI_HEAP_REFERENCE_JNI_LOCAL" num="25">
3313 Heap root reference: JNI local reference.
3314 </constant>
3315 <constant id="JVMTI_HEAP_REFERENCE_THREAD" num="26">
3316 Heap root reference: Thread.
3317 </constant>
3318 <constant id="JVMTI_HEAP_REFERENCE_OTHER" num="27">
3319 Heap root reference: other heap root reference.
3320 </constant>
3321 </constants>
3322
3323 <p/>
3324 Definitions for the single character type descriptors of
3325 primitive types.
3326
3327 <constants id="jvmtiPrimitiveType"
3328 label="Primitive Type Enumeration"
3329 kind="enum"
3330 since="1.1">
3331 <constant id="JVMTI_PRIMITIVE_TYPE_BOOLEAN" num="90">
3332 'Z' - Java programming language <code>boolean</code> - JNI <code>jboolean</code>
3333 </constant>
3334 <constant id="JVMTI_PRIMITIVE_TYPE_BYTE" num="66">
3335 'B' - Java programming language <code>byte</code> - JNI <code>jbyte</code>
3336 </constant>
3337 <constant id="JVMTI_PRIMITIVE_TYPE_CHAR" num="67">
3338 'C' - Java programming language <code>char</code> - JNI <code>jchar</code>
3339 </constant>
3340 <constant id="JVMTI_PRIMITIVE_TYPE_SHORT" num="83">
3341 'S' - Java programming language <code>short</code> - JNI <code>jshort</code>
3342 </constant>
3343 <constant id="JVMTI_PRIMITIVE_TYPE_INT" num="73">
3344 'I' - Java programming language <code>int</code> - JNI <code>jint</code>
3345 </constant>
3346 <constant id="JVMTI_PRIMITIVE_TYPE_LONG" num="74">
3347 'J' - Java programming language <code>long</code> - JNI <code>jlong</code>
3348 </constant>
3349 <constant id="JVMTI_PRIMITIVE_TYPE_FLOAT" num="70">
3350 'F' - Java programming language <code>float</code> - JNI <code>jfloat</code>
3351 </constant>
3352 <constant id="JVMTI_PRIMITIVE_TYPE_DOUBLE" num="68">
3353 'D' - Java programming language <code>double</code> - JNI <code>jdouble</code>
3354 </constant>
3355 </constants>
3356 </intro>
3357
3358 <typedef id="jvmtiHeapReferenceInfoField"
3359 label="Reference information structure for Field references"
3360 since="1.1">
3361 <description>
3362 Reference information returned for
3363 <datalink id="JVMTI_HEAP_REFERENCE_FIELD"/> and
3364 <datalink id="JVMTI_HEAP_REFERENCE_STATIC_FIELD"/> references.
3365 </description>
3366 <field id="index">
3367 <jint/>
3368 <description>
3369 For <datalink id="JVMTI_HEAP_REFERENCE_FIELD"/>, the
3370 referrer object is not a class or an inteface.
3371 In this case, <code>index</code> is the index of the field
3372 in the class of the referrer object.
3373 This class is referred to below as <i>C</i>.
3374 <p/>
3375 For <datalink id="JVMTI_HEAP_REFERENCE_STATIC_FIELD"/>,
3376 the referrer object is a class (referred to below as <i>C</i>)
3377 or an interface (referred to below as <i>I</i>).
3378 In this case, <code>index</code> is the index of the field in
3379 that class or interface.
3380 <p/>
3381 If the referrer object is not an interface, then the field
3382 indices are determined as follows:
3383 <ul>
3384 <li>make a list of all the fields in <i>C</i> and its
3385 superclasses, starting with all the fields in
3386 <code>java.lang.Object</code> and ending with all the
3387 fields in <i>C</i>.</li>
3388 <li>Within this list, put
3389 the fields for a given class in the order returned by
3390 <functionlink id="GetClassFields"/>.</li>
3391 <li>Assign the fields in this list indices
3392 <i>n</i>, <i>n</i>+1, ..., in order, where <i>n</i>
3393 is the count of the fields in all the interfaces
3394 implemented by <i>C</i>.
3395 Note that <i>C</i> implements all interfaces
3396 directly implemented by its superclasses; as well
3397 as all superinterfaces of these interfaces.</li>
3398 </ul>
3399 If the referrer object is an interface, then the field
3400 indices are determined as follows:
3401 <ul>
3402 <li>make a list of the fields directly declared in
3403 <i>I</i>.</li>
3404 <li>Within this list, put
3405 the fields in the order returned by
3406 <functionlink id="GetClassFields"/>.</li>
3407 <li>Assign the fields in this list indices
3408 <i>n</i>, <i>n</i>+1, ..., in order, where <i>n</i>
3409 is the count of the fields in all the superinterfaces
3410 of <i>I</i>.</li>
3411 </ul>
3412 All fields are included in this computation, regardless of
3413 field modifier (static, public, private, etc).
3414 <p/>
3415 For example, given the following classes and interfaces:
3416 <example>
3417 interface I0 {
3418 int p = 0;
3419 }
3420
3421 interface I1 extends I0 {
3422 int x = 1;
3423 }
3424
3425 interface I2 extends I0 {
3426 int y = 2;
3427 }
3428
3429 class C1 implements I1 {
3430 public static int a = 3;
3431 private int b = 4;
3432 }
3433
3434 class C2 extends C1 implements I2 {
3435 static int q = 5;
3436 final int r = 6;
3437 }
3438 </example>
3439 Assume that <functionlink id="GetClassFields"/> called on
3440 <code>C1</code> returns the fields of <code>C1</code> in the
3441 order: a, b; and that the fields of <code>C2</code> are
3442 returned in the order: q, r.
3443 An instance of class <code>C1</code> will have the
3444 following field indices:
3445 <dl><dd><table>
3446 <tr>
3447 <td>
3448 a
3449 </td>
3450 <td>
3451 2
3452 </td>
3453 <td align="left">
3454 The count of the fields in the interfaces
3455 implemented by <code>C1</code> is two (<i>n</i>=2):
3456 <code>p</code> of <code>I0</code>
3457 and <code>x</code> of <code>I1</code>.
3458 </td>
3459 </tr>
3460 <tr>
3461 <td>
3462 b
3463 </td>
3464 <td>
3465 3
3466 </td>
3467 <td align="left">
3468 the subsequent index.
3469 </td>
3470 </tr>
3471 </table></dd></dl>
3472 The class <code>C1</code> will have the same field indices.
3473 <p/>
3474 An instance of class <code>C2</code> will have the
3475 following field indices:
3476 <dl><dd><table>
3477 <tr>
3478 <td>
3479 a
3480 </td>
3481 <td>
3482 3
3483 </td>
3484 <td align="left">
3485 The count of the fields in the interfaces
3486 implemented by <code>C2</code> is three (<i>n</i>=3):
3487 <code>p</code> of <code>I0</code>,
3488 <code>x</code> of <code>I1</code> and <code>y</code> of <code>I2</code>
3489 (an interface of <code>C2</code>). Note that the field <code>p</code>
3490 of <code>I0</code> is only included once.
3491 </td>
3492 </tr>
3493 <tr>
3494 <td>
3495 b
3496 </td>
3497 <td>
3498 4
3499 </td>
3500 <td align="left">
3501 the subsequent index to "a".
3502 </td>
3503 </tr>
3504 <tr>
3505 <td>
3506 q
3507 </td>
3508 <td>
3509 5
3510 </td>
3511 <td align="left">
3512 the subsequent index to "b".
3513 </td>
3514 </tr>
3515 <tr>
3516 <td>
3517 r
3518 </td>
3519 <td>
3520 6
3521 </td>
3522 <td align="left">
3523 the subsequent index to "q".
3524 </td>
3525 </tr>
3526 </table></dd></dl>
3527 The class <code>C2</code> will have the same field indices.
3528 Note that a field may have a different index depending on the
3529 object that is viewing it -- for example field "a" above.
3530 Note also: not all field indices may be visible from the
3531 callbacks, but all indices are shown for illustrative purposes.
3532 <p/>
3533 The interface <code>I1</code> will have the
3534 following field indices:
3535 <dl><dd><table>
3536 <tr>
3537 <td>
3538 x
3539 </td>
3540 <td>
3541 1
3542 </td>
3543 <td align="left">
3544 The count of the fields in the superinterfaces
3545 of <code>I1</code> is one (<i>n</i>=1):
3546 <code>p</code> of <code>I0</code>.
3547 </td>
3548 </tr>
3549 </table></dd></dl>
3550 </description>
3551 </field>
3552 </typedef>
3553
3554 <typedef id="jvmtiHeapReferenceInfoArray"
3555 label="Reference information structure for Array references"
3556 since="1.1">
3557 <description>
3558 Reference information returned for
3559 <datalink id="JVMTI_HEAP_REFERENCE_ARRAY_ELEMENT"/> references.
3560 </description>
3561 <field id="index">
3562 <jint/>
3563 <description>
3564 The array index.
3565 </description>
3566 </field>
3567 </typedef>
3568
3569 <typedef id="jvmtiHeapReferenceInfoConstantPool"
3570 label="Reference information structure for Constant Pool references"
3571 since="1.1">
3572 <description>
3573 Reference information returned for
3574 <datalink id="JVMTI_HEAP_REFERENCE_CONSTANT_POOL"/> references.
3575 </description>
3576 <field id="index">
3577 <jint/>
3578 <description>
3579 The index into the constant pool of the class. See the
3580 <vmspeclink id="ClassFile.doc.html#20080"
3581 name="Constant Pool section"/>
3582 description.
3583 </description>
3584 </field>
3585 </typedef>
3586
3587 <typedef id="jvmtiHeapReferenceInfoStackLocal"
3588 label="Reference information structure for Local Variable references"
3589 since="1.1">
3590 <description>
3591 Reference information returned for
3592 <datalink id="JVMTI_HEAP_REFERENCE_STACK_LOCAL"/> references.
3593 </description>
3594 <field id="thread_tag">
3595 <jlong/>
3596 <description>
3597 The tag of the thread corresponding to this stack, zero if not tagged.
3598 </description>
3599 </field>
3600 <field id="thread_id">
3601 <jlong/>
3602 <description>
3603 The unique thread ID of the thread corresponding to this stack.
3604 </description>
3605 </field>
3606 <field id="depth">
3607 <jint/>
3608 <description>
3609 The depth of the frame.
3610 </description>
3611 </field>
3612 <field id="method">
3613 <jmethodID/>
3614 <description>
3615 The method executing in this frame.
3616 </description>
3617 </field>
3618 <field id="location">
3619 <jlocation/>
3620 <description>
3621 The currently executing location in this frame.
3622 </description>
3623 </field>
3624 <field id="slot">
3625 <jint/>
3626 <description>
3627 The slot number of the local variable.
3628 </description>
3629 </field>
3630 </typedef>
3631
3632 <typedef id="jvmtiHeapReferenceInfoJniLocal"
3633 label="Reference information structure for JNI local references"
3634 since="1.1">
3635 <description>
3636 Reference information returned for
3637 <datalink id="JVMTI_HEAP_REFERENCE_JNI_LOCAL"/> references.
3638 </description>
3639 <field id="thread_tag">
3640 <jlong/>
3641 <description>
3642 The tag of the thread corresponding to this stack, zero if not tagged.
3643 </description>
3644 </field>
3645 <field id="thread_id">
3646 <jlong/>
3647 <description>
3648 The unique thread ID of the thread corresponding to this stack.
3649 </description>
3650 </field>
3651 <field id="depth">
3652 <jint/>
3653 <description>
3654 The depth of the frame.
3655 </description>
3656 </field>
3657 <field id="method">
3658 <jmethodID/>
3659 <description>
3660 The method executing in this frame.
3661 </description>
3662 </field>
3663 </typedef>
3664
3665 <typedef id="jvmtiHeapReferenceInfoReserved"
3666 label="Reference information structure for Other references"
3667 since="1.1">
3668 <description>
3669 Reference information returned for other references.
3670 </description>
3671 <field id="reserved1">
3672 <jlong/>
3673 <description>
3674 reserved for future use.
3675 </description>
3676 </field>
3677 <field id="reserved2">
3678 <jlong/>
3679 <description>
3680 reserved for future use.
3681 </description>
3682 </field>
3683 <field id="reserved3">
3684 <jlong/>
3685 <description>
3686 reserved for future use.
3687 </description>
3688 </field>
3689 <field id="reserved4">
3690 <jlong/>
3691 <description>
3692 reserved for future use.
3693 </description>
3694 </field>
3695 <field id="reserved5">
3696 <jlong/>
3697 <description>
3698 reserved for future use.
3699 </description>
3700 </field>
3701 <field id="reserved6">
3702 <jlong/>
3703 <description>
3704 reserved for future use.
3705 </description>
3706 </field>
3707 <field id="reserved7">
3708 <jlong/>
3709 <description>
3710 reserved for future use.
3711 </description>
3712 </field>
3713 <field id="reserved8">
3714 <jlong/>
3715 <description>
3716 reserved for future use.
3717 </description>
3718 </field>
3719 </typedef>
3720
3721 <uniontypedef id="jvmtiHeapReferenceInfo"
3722 label="Reference information structure"
3723 since="1.1">
3724 <description>
3725 The information returned about referrers.
3726 Represented as a union of the various kinds of reference information.
3727 </description>
3728 <field id="field">
3729 <struct>jvmtiHeapReferenceInfoField</struct>
3730 <description>
3731 The referrer information for
3732 <datalink id="JVMTI_HEAP_REFERENCE_FIELD"/>
3733 and <datalink id="JVMTI_HEAP_REFERENCE_STATIC_FIELD"/> references.
3734 </description>
3735 </field>
3736 <field id="array">
3737 <struct>jvmtiHeapReferenceInfoArray</struct>
3738 <description>
3739 The referrer information for
3740 For <datalink id="JVMTI_HEAP_REFERENCE_ARRAY_ELEMENT"/> references.
3741 </description>
3742 </field>
3743 <field id="constant_pool">
3744 <struct>jvmtiHeapReferenceInfoConstantPool</struct>
3745 <description>
3746 The referrer information for
3747 For <datalink id="JVMTI_HEAP_REFERENCE_CONSTANT_POOL"/> references.
3748 </description>
3749 </field>
3750 <field id="stack_local">
3751 <struct>jvmtiHeapReferenceInfoStackLocal</struct>
3752 <description>
3753 The referrer information for
3754 For <datalink id="JVMTI_HEAP_REFERENCE_STACK_LOCAL"/> references.
3755 </description>
3756 </field>
3757 <field id="jni_local">
3758 <struct>jvmtiHeapReferenceInfoJniLocal</struct>
3759 <description>
3760 The referrer information for
3761 For <datalink id="JVMTI_HEAP_REFERENCE_JNI_LOCAL"/> references.
3762 </description>
3763 </field>
3764 <field id="other">
3765 <struct>jvmtiHeapReferenceInfoReserved</struct>
3766 <description>
3767 reserved for future use.
3768 </description>
3769 </field>
3770 </uniontypedef>
3771
3772 <typedef id="jvmtiHeapCallbacks"
3773 label="Heap callback function structure"
3774 since="1.1">
3775 <field id="heap_iteration_callback">
3776 <ptrtype>
3777 <struct>jvmtiHeapIterationCallback</struct>
3778 </ptrtype>
3779 <description>
3780 The callback to be called to describe an
3781 object in the heap. Used by the
3782 <functionlink id="IterateThroughHeap"/> function, ignored by the
3783 <functionlink id="FollowReferences"/> function.
3784 </description>
3785 </field>
3786 <field id="heap_reference_callback">
3787 <ptrtype>
3788 <struct>jvmtiHeapReferenceCallback</struct>
3789 </ptrtype>
3790 <description>
3791 The callback to be called to describe an
3792 object reference. Used by the
3793 <functionlink id="FollowReferences"/> function, ignored by the
3794 <functionlink id="IterateThroughHeap"/> function.
3795 </description>
3796 </field>
3797 <field id="primitive_field_callback">
3798 <ptrtype>
3799 <struct>jvmtiPrimitiveFieldCallback</struct>
3800 </ptrtype>
3801 <description>
3802 The callback to be called to describe a
3803 primitive field.
3804 </description>
3805 </field>
3806 <field id="array_primitive_value_callback">
3807 <ptrtype>
3808 <struct>jvmtiArrayPrimitiveValueCallback</struct>
3809 </ptrtype>
3810 <description>
3811 The callback to be called to describe an
3812 array of primitive values.
3813 </description>
3814 </field>
3815 <field id="string_primitive_value_callback">
3816 <ptrtype>
3817 <struct>jvmtiStringPrimitiveValueCallback</struct>
3818 </ptrtype>
3819 <description>
3820 The callback to be called to describe a String value.
3821 </description>
3822 </field>
3823 <field id="reserved5">
3824 <ptrtype>
3825 <struct>jvmtiReservedCallback</struct>
3826 </ptrtype>
3827 <description>
3828 Reserved for future use..
3829 </description>
3830 </field>
3831 <field id="reserved6">
3832 <ptrtype>
3833 <struct>jvmtiReservedCallback</struct>
3834 </ptrtype>
3835 <description>
3836 Reserved for future use..
3837 </description>
3838 </field>
3839 <field id="reserved7">
3840 <ptrtype>
3841 <struct>jvmtiReservedCallback</struct>
3842 </ptrtype>
3843 <description>
3844 Reserved for future use..
3845 </description>
3846 </field>
3847 <field id="reserved8">
3848 <ptrtype>
3849 <struct>jvmtiReservedCallback</struct>
3850 </ptrtype>
3851 <description>
3852 Reserved for future use..
3853 </description>
3854 </field>
3855 <field id="reserved9">
3856 <ptrtype>
3857 <struct>jvmtiReservedCallback</struct>
3858 </ptrtype>
3859 <description>
3860 Reserved for future use..
3861 </description>
3862 </field>
3863 <field id="reserved10">
3864 <ptrtype>
3865 <struct>jvmtiReservedCallback</struct>
3866 </ptrtype>
3867 <description>
3868 Reserved for future use..
3869 </description>
3870 </field>
3871 <field id="reserved11">
3872 <ptrtype>
3873 <struct>jvmtiReservedCallback</struct>
3874 </ptrtype>
3875 <description>
3876 Reserved for future use..
3877 </description>
3878 </field>
3879 <field id="reserved12">
3880 <ptrtype>
3881 <struct>jvmtiReservedCallback</struct>
3882 </ptrtype>
3883 <description>
3884 Reserved for future use..
3885 </description>
3886 </field>
3887 <field id="reserved13">
3888 <ptrtype>
3889 <struct>jvmtiReservedCallback</struct>
3890 </ptrtype>
3891 <description>
3892 Reserved for future use..
3893 </description>
3894 </field>
3895 <field id="reserved14">
3896 <ptrtype>
3897 <struct>jvmtiReservedCallback</struct>
3898 </ptrtype>
3899 <description>
3900 Reserved for future use..
3901 </description>
3902 </field>
3903 <field id="reserved15">
3904 <ptrtype>
3905 <struct>jvmtiReservedCallback</struct>
3906 </ptrtype>
3907 <description>
3908 Reserved for future use..
3909 </description>
3910 </field>
3911 </typedef>
3912
3913
3914 <intro>
3915 <rationale>
3916 The heap dumping functionality (below) uses a callback
3917 for each object. While it would seem that a buffered approach
3918 would provide better throughput, tests do
3919 not show this to be the case--possibly due to locality of
3920 memory reference or array access overhead.
3921 </rationale>
3922
3923 <issue>
3924 Still under investigation as to if java.lang.ref references
3925 are reported as a different type of reference.
3926 </issue>
3927
3928 <issue>
3929 Should or can an indication of the cost or relative cost of
3930 these operations be included?
3931 </issue>
3932
3933 </intro>
3934
3935 <callback id="jvmtiHeapIterationCallback" since="1.1">
3936 <jint/>
3937 <synopsis>Heap Iteration Callback</synopsis>
3938 <description>
3939 Agent supplied callback function.
3940 Describes (but does not pass in) an object in the heap.
3941 <p/>
3942 This function should return a bit vector of the desired
3943 <datalink id="jvmtiHeapVisitControl">visit control flags</datalink>.
3944 This will determine if the entire iteration should be aborted
3945 (the <code>JVMTI_VISIT_OBJECTS</code> flag is ignored).
3946 <p/>
3947 See the <internallink id="heapCallbacks">heap callback
3948 function restrictions</internallink>.
3949 </description>
3950 <parameters>
3951 <param id="class_tag">
3952 <jlong/>
3953 <description>
3954 The tag of the class of object (zero if the class is not tagged).
3955 If the object represents a runtime class,
3956 the <code>class_tag</code> is the tag
3957 associated with <code>java.lang.Class</code>
3958 (zero if <code>java.lang.Class</code> is not tagged).
3959 </description>
3960 </param>
3961 <param id="size">
3962 <jlong/>
3963 <description>
3964 Size of the object (in bytes). See <functionlink id="GetObjectSize"/>.
3965 </description>
3966 </param>
3967 <param id="tag_ptr">
3968 <outptr><jlong/></outptr>
3969 <description>
3970 The object tag value, or zero if the object is not tagged.
3971 To set the tag value to be associated with the object
3972 the agent sets the <code>jlong</code> pointed to by the parameter.
3973 </description>
3974 </param>
3975 <param id="length">
3976 <jint/>
3977 <description>
3978 If this object is an array, the length of the array. Otherwise negative one (-1).
3979 </description>
3980 </param>
3981 <param id="user_data">
3982 <outptr><void/></outptr>
3983 <description>
3984 The user supplied data that was passed into the iteration function.
3985 </description>
3986 </param>
3987 </parameters>
3988 </callback>
3989
3990 <callback id="jvmtiHeapReferenceCallback" since="1.1">
3991 <jint/>
3992 <synopsis>Heap Reference Callback</synopsis>
3993 <description>
3994 Agent supplied callback function.
3995 Describes a reference from an object or the VM (the referrer) to another object
3996 (the referree) or a heap root to a referree.
3997 <p/>
3998 This function should return a bit vector of the desired
3999 <datalink id="jvmtiHeapVisitControl">visit control flags</datalink>.
4000 This will determine if the objects referenced by the referree
4001 should be visited or if the entire iteration should be aborted.
4002 <p/>
4003 See the <internallink id="heapCallbacks">heap callback
4004 function restrictions</internallink>.
4005 </description>
4006 <parameters>
4007 <param id="reference_kind">
4008 <enum>jvmtiHeapReferenceKind</enum>
4009 <description>
4010 The kind of reference.
4011 </description>
4012 </param>
4013 <param id="reference_info">
4014 <inptr>
4015 <struct>jvmtiHeapReferenceInfo</struct>
4016 </inptr>
4017 <description>
4018 Details about the reference.
4019 Set when the <paramlink id="reference_kind"/> is
4020 <datalink id="JVMTI_HEAP_REFERENCE_FIELD"/>,
4021 <datalink id="JVMTI_HEAP_REFERENCE_STATIC_FIELD"/>,
4022 <datalink id="JVMTI_HEAP_REFERENCE_ARRAY_ELEMENT"/>,
4023 <datalink id="JVMTI_HEAP_REFERENCE_CONSTANT_POOL"/>,
4024 <datalink id="JVMTI_HEAP_REFERENCE_STACK_LOCAL"/>,
4025 or <datalink id="JVMTI_HEAP_REFERENCE_JNI_LOCAL"/>.
4026 Otherwise <code>NULL</code>.
4027 </description>
4028 </param>
4029 <param id="class_tag">
4030 <jlong/>
4031 <description>
4032 The tag of the class of referree object (zero if the class is not tagged).
4033 If the referree object represents a runtime class,
4034 the <code>class_tag</code> is the tag
4035 associated with <code>java.lang.Class</code>
4036 (zero if <code>java.lang.Class</code> is not tagged).
4037 </description>
4038 </param>
4039 <param id="referrer_class_tag">
4040 <jlong/>
4041 <description>
4042 The tag of the class of the referrer object (zero if the class is not tagged
4043 or the referree is a heap root). If the referrer object represents a runtime
4044 class, the <code>referrer_class_tag</code> is the tag associated with
4045 the <code>java.lang.Class</code>
4046 (zero if <code>java.lang.Class</code> is not tagged).
4047 </description>
4048 </param>
4049 <param id="size">
4050 <jlong/>
4051 <description>
4052 Size of the referree object (in bytes).
4053 See <functionlink id="GetObjectSize"/>.
4054 </description>
4055 </param>
4056 <param id="tag_ptr">
4057 <outptr><jlong/></outptr>
4058 <description>
4059 Points to the referree object tag value, or zero if the object is not
4060 tagged.
4061 To set the tag value to be associated with the object
4062 the agent sets the <code>jlong</code> pointed to by the parameter.
4063 </description>
4064 </param>
4065 <param id="referrer_tag_ptr">
4066 <outptr><jlong/></outptr>
4067 <description>
4068 Points to the tag of the referrer object, or
4069 points to the zero if the referrer
4070 object is not tagged.
4071 <code>NULL</code> if the referrer in not an object (that is,
4072 this callback is reporting a heap root).
4073 To set the tag value to be associated with the referrer object
4074 the agent sets the <code>jlong</code> pointed to by the parameter.
4075 If this callback is reporting a reference from an object to itself,
4076 <code>referrer_tag_ptr == tag_ptr</code>.
4077 </description>
4078 </param>
4079 <param id="length">
4080 <jint/>
4081 <description>
4082 If this object is an array, the length of the array. Otherwise negative one (-1).
4083 </description>
4084 </param>
4085 <param id="user_data">
4086 <outptr><void/></outptr>
4087 <description>
4088 The user supplied data that was passed into the iteration function.
4089 </description>
4090 </param>
4091 </parameters>
4092 </callback>
4093
4094 <callback id="jvmtiPrimitiveFieldCallback" since="1.1">
4095 <jint/>
4096 <synopsis>Primitive Field Callback</synopsis>
4097 <description>
4098 Agent supplied callback function which
4099 describes a primitive field of an object (<i>the object</i>).
4100 A primitive field is a field whose type is a primitive type.
4101 This callback will describe a static field if the object is a class,
4102 and otherwise will describe an instance field.
4103 <p/>
4104 This function should return a bit vector of the desired
4105 <datalink id="jvmtiHeapVisitControl">visit control flags</datalink>.
4106 This will determine if the entire iteration should be aborted
4107 (the <code>JVMTI_VISIT_OBJECTS</code> flag is ignored).
4108 <p/>
4109 See the <internallink id="heapCallbacks">heap callback
4110 function restrictions</internallink>.
4111 </description>
4112 <parameters>
4113 <param id="kind">
4114 <enum>jvmtiHeapReferenceKind</enum>
4115 <description>
4116 The kind of field -- instance or static (<datalink id="JVMTI_HEAP_REFERENCE_FIELD"/> or
4117 <datalink id="JVMTI_HEAP_REFERENCE_STATIC_FIELD"/>).
4118 </description>
4119 </param>
4120 <param id="info">
4121 <inptr>
4122 <struct>jvmtiHeapReferenceInfo</struct>
4123 </inptr>
4124 <description>
4125 Which field (the field index).
4126 </description>
4127 </param>
4128 <param id="object_class_tag">
4129 <jlong/>
4130 <description>
4131 The tag of the class of the object (zero if the class is not tagged).
4132 If the object represents a runtime class, the
4133 <code>object_class_tag</code> is the tag
4134 associated with <code>java.lang.Class</code>
4135 (zero if <code>java.lang.Class</code> is not tagged).
4136 </description>
4137 </param>
4138 <param id="object_tag_ptr">
4139 <outptr><jlong/></outptr>
4140 <description>
4141 Points to the tag of the object, or zero if the object is not
4142 tagged.
4143 To set the tag value to be associated with the object
4144 the agent sets the <code>jlong</code> pointed to by the parameter.
4145 </description>
4146 </param>
4147 <param id="value">
4148 <jvalue/>
4149 <description>
4150 The value of the field.
4151 </description>
4152 </param>
4153 <param id="value_type">
4154 <enum>jvmtiPrimitiveType</enum>
4155 <description>
4156 The type of the field.
4157 </description>
4158 </param>
4159 <param id="user_data">
4160 <outptr><void/></outptr>
4161 <description>
4162 The user supplied data that was passed into the iteration function.
4163 </description>
4164 </param>
4165 </parameters>
4166 </callback>
4167
4168 <callback id="jvmtiArrayPrimitiveValueCallback" since="1.1">
4169 <jint/>
4170 <synopsis>Array Primitive Value Callback</synopsis>
4171 <description>
4172 Agent supplied callback function.
4173 Describes the values in an array of a primitive type.
4174 <p/>
4175 This function should return a bit vector of the desired
4176 <datalink id="jvmtiHeapVisitControl">visit control flags</datalink>.
4177 This will determine if the entire iteration should be aborted
4178 (the <code>JVMTI_VISIT_OBJECTS</code> flag is ignored).
4179 <p/>
4180 See the <internallink id="heapCallbacks">heap callback
4181 function restrictions</internallink>.
4182 </description>
4183 <parameters>
4184 <param id="class_tag">
4185 <jlong/>
4186 <description>
4187 The tag of the class of the array object (zero if the class is not tagged).
4188 </description>
4189 </param>
4190 <param id="size">
4191 <jlong/>
4192 <description>
4193 Size of the array (in bytes).
4194 See <functionlink id="GetObjectSize"/>.
4195 </description>
4196 </param>
4197 <param id="tag_ptr">
4198 <outptr><jlong/></outptr>
4199 <description>
4200 Points to the tag of the array object, or zero if the object is not
4201 tagged.
4202 To set the tag value to be associated with the object
4203 the agent sets the <code>jlong</code> pointed to by the parameter.
4204 </description>
4205 </param>
4206 <param id="element_count">
4207 <jint/>
4208 <description>
4209 The length of the primitive array.
4210 </description>
4211 </param>
4212 <param id="element_type">
4213 <enum>jvmtiPrimitiveType</enum>
4214 <description>
4215 The type of the elements of the array.
4216 </description>
4217 </param>
4218 <param id="elements">
4219 <vmbuf><void/></vmbuf>
4220 <description>
4221 The elements of the array in a packed array of <code>element_count</code>
4222 items of <code>element_type</code> size each.
4223 </description>
4224 </param>
4225 <param id="user_data">
4226 <outptr><void/></outptr>
4227 <description>
4228 The user supplied data that was passed into the iteration function.
4229 </description>
4230 </param>
4231 </parameters>
4232 </callback>
4233
4234 <callback id="jvmtiStringPrimitiveValueCallback" since="1.1">
4235 <jint/>
4236 <synopsis>String Primitive Value Callback</synopsis>
4237 <description>
4238 Agent supplied callback function.
4239 Describes the value of a java.lang.String.
4240 <p/>
4241 This function should return a bit vector of the desired
4242 <datalink id="jvmtiHeapVisitControl">visit control flags</datalink>.
4243 This will determine if the entire iteration should be aborted
4244 (the <code>JVMTI_VISIT_OBJECTS</code> flag is ignored).
4245 <p/>
4246 See the <internallink id="heapCallbacks">heap callback
4247 function restrictions</internallink>.
4248 </description>
4249 <parameters>
4250 <param id="class_tag">
4251 <jlong/>
4252 <description>
4253 The tag of the class of the String class (zero if the class is not tagged).
4254 <issue>Is this needed?</issue>
4255 </description>
4256 </param>
4257 <param id="size">
4258 <jlong/>
4259 <description>
4260 Size of the string (in bytes).
4261 See <functionlink id="GetObjectSize"/>.
4262 </description>
4263 </param>
4264 <param id="tag_ptr">
4265 <outptr><jlong/></outptr>
4266 <description>
4267 Points to the tag of the String object, or zero if the object is not
4268 tagged.
4269 To set the tag value to be associated with the object
4270 the agent sets the <code>jlong</code> pointed to by the parameter.
4271 </description>
4272 </param>
4273 <param id="value">
4274 <vmbuf><jchar/></vmbuf>
4275 <description>
4276 The value of the String, encoded as a Unicode string.
4277 </description>
4278 </param>
4279 <param id="value_length">
4280 <jint/>
4281 <description>
4282 The length of the string.
4283 The length is equal to the number of 16-bit Unicode
4284 characters in the string.
4285 </description>
4286 </param>
4287 <param id="user_data">
4288 <outptr><void/></outptr>
4289 <description>
4290 The user supplied data that was passed into the iteration function.
4291 </description>
4292 </param>
4293 </parameters>
4294 </callback>
4295
4296
4297 <callback id="jvmtiReservedCallback" since="1.1">
4298 <jint/>
4299 <synopsis>reserved for future use Callback</synopsis>
4300 <description>
4301 Placeholder -- reserved for future use.
4302 </description>
4303 <parameters>
4304 </parameters>
4305 </callback>
4306
4307 <function id="FollowReferences" num="115" since="1.1">
4308 <synopsis>Follow References</synopsis>
4309 <description>
4310 This function initiates a traversal over the objects that are
4311 directly and indirectly reachable from the specified object or,
4312 if <code>initial_object</code> is not specified, all objects
4313 reachable from the heap roots.
4314 The heap root are the set of system classes,
4315 JNI globals, references from thread stacks, and other objects used as roots
4316 for the purposes of garbage collection.
4317 <p/>
4318 This function operates by traversing the reference graph.
4319 Let <i>A</i>, <i>B</i>, ... represent objects.
4320 When a reference from <i>A</i> to <i>B</i> is traversed,
4321 when a reference from a heap root to <i>B</i> is traversed,
4322 or when <i>B</i> is specified as the <paramlink id="initial_object"/>,
4323 then <i>B</i> is said to be <i>visited</i>.
4324 A reference from <i>A</i> to <i>B</i> is not traversed until <i>A</i>
4325 is visited.
4326 References are reported in the same order that the references are traversed.
4327 Object references are reported by invoking the agent supplied
4328 callback function <functionlink id="jvmtiHeapReferenceCallback"/>.
4329 In a reference from <i>A</i> to <i>B</i>, <i>A</i> is known
4330 as the <i>referrer</i> and <i>B</i> as the <i>referree</i>.
4331 The callback is invoked exactly once for each reference from a referrer;
4332 this is true even if there are reference cycles or multiple paths to
4333 the referrer.
4334 There may be more than one reference between a referrer and a referree,
4335 each reference is reported.
4336 These references may be distinguished by examining the
4337 <datalink
4338 id="jvmtiHeapReferenceCallback.reference_kind"><code>reference_kind</code></datalink>
4339 and
4340 <datalink
4341 id="jvmtiHeapReferenceCallback.reference_info"><code>reference_info</code></datalink>
4342 parameters of the <functionlink id="jvmtiHeapReferenceCallback"/> callback.
4343 <p/>
4344 This function reports a Java programming language view of object references,
4345 not a virtual machine implementation view. The following object references
4346 are reported when they are non-null:
4347 <ul>
4348 <li>Instance objects report references to each non-primitive instance fields
4349 (including inherited fields).</li>
4350 <li>Instance objects report a reference to the object type (class).</li>
4351 <li>Classes report a reference to the superclass and directly
4352 implemented/extended interfaces.</li>
4353 <li>Classes report a reference to the class loader, protection domain,
4354 signers, and resolved entries in the constant pool.</li>
4355 <li>Classes report a reference to each directly declared non-primitive
4356 static field.</li>
4357 <li>Arrays report a reference to the array type (class) and each
4358 array element.</li>
4359 <li>Primitive arrays report a reference to the array type.</li>
4360 </ul>
4361 <p/>
4362 This function can also be used to examine primitive (non-object) values.
4363 The primitive value of an array or String
4364 is reported after the object has been visited;
4365 it is reported by invoking the agent supplied callback function
4366 <functionlink id="jvmtiArrayPrimitiveValueCallback"/> or
4367 <functionlink id="jvmtiStringPrimitiveValueCallback"/>.
4368 A primitive field
4369 is reported after the object with that field is visited;
4370 it is reported by invoking the agent supplied callback function
4371 <functionlink id="jvmtiPrimitiveFieldCallback"/>.
4372 <p/>
4373 Whether a callback is provided or is <code>NULL</code> only determines
4374 whether the callback will be invoked, it does not influence
4375 which objects are visited nor does it influence whether other callbacks
4376 will be invoked.
4377 However, the
4378 <datalink id="jvmtiHeapVisitControl">visit control flags</datalink>
4379 returned by <functionlink id="jvmtiHeapReferenceCallback"/>
4380 do determine if the objects referenced by the
4381 current object as visited.
4382 The <datalink id="jvmtiHeapFilter">heap filter flags</datalink>
4383 and <paramlink id="klass"/> provided as parameters to this function
4384 do not control which objects are visited but they do control which
4385 objects and primitive values are reported by the callbacks.
4386 For example, if the only callback that was set is
4387 <paramlink id="array_primitive_value_callback"/> and <code>klass</code>
4388 is set to the array of bytes class, then only arrays of byte will be
4389 reported.
4390 The table below summarizes this:
4391 <p/>
4392 <table>
4393 <tr>
4394 <th/>
4395 <th>
4396 Controls objects visited
4397 </th>
4398 <th>
4399 Controls objects reported
4400 </th>
4401 <th>
4402 Controls primitives reported
4403 </th>
4404 </tr>
4405 <tr>
4406 <th align="left">
4407 the
4408 <datalink id="jvmtiHeapVisitControl">Heap Visit Control Flags</datalink>
4409 returned by <functionlink id="jvmtiHeapReferenceCallback"/>
4410 </th>
4411 <td>
4412 <b>Yes</b>
4413 </td>
4414 <td>
4415 <b>Yes</b>, since visits are controlled
4416 </td>
4417 <td>
4418 <b>Yes</b>, since visits are controlled
4419 </td>
4420 </tr>
4421 <tr>
4422 <th align="left">
4423 <fieldlink id="object_reference_callback" struct="jvmtiHeapCallbacks"/>
4424 in <paramlink id="callbacks"/> set
4425 </th>
4426 <td>
4427 No
4428 </td>
4429 <td>
4430 <b>Yes</b>
4431 </td>
4432 <td>
4433 No
4434 </td>
4435 </tr>
4436 <tr>
4437 <th align="left">
4438 <paramlink id="heap_filter"/>
4439 </th>
4440 <td>
4441 No
4442 </td>
4443 <td>
4444 <b>Yes</b>
4445 </td>
4446 <td>
4447 <b>Yes</b>
4448 </td>
4449 </tr>
4450 <tr>
4451 <th align="left">
4452 <paramlink id="klass"/>
4453 </th>
4454 <td>
4455 No
4456 </td>
4457 <td>
4458 <b>Yes</b>
4459 </td>
4460 <td>
4461 <b>Yes</b>
4462 </td>
4463 </tr>
4464 </table>
4465 <p/>
4466 During the execution of this function the state of the heap
4467 does not change: no objects are allocated, no objects are
4468 garbage collected, and the state of objects (including
4469 held values) does not change.
4470 As a result, threads executing Java
4471 programming language code, threads attempting to resume the
4472 execution of Java programming language code, and threads
4473 attempting to execute JNI functions are typically stalled.
4474 </description>
4475 <origin>new</origin>
4476 <capabilities>
4477 <required id="can_tag_objects"></required>
4478 </capabilities>
4479 <parameters>
4480 <param id="heap_filter">
4481 <jint/>
4482 <description>
4483 This bit vector of
4484 <datalink id="jvmtiHeapFilter">heap filter flags</datalink>.
4485 restricts the objects for which the callback function is called.
4486 This applies to both the object and primitive callbacks.
4487 </description>
4488 </param>
4489 <param id="klass">
4490 <ptrtype>
4491 <jclass/>
4492 <nullok>callbacks are not limited to instances of a particular
4493 class</nullok>
4494 </ptrtype>
4495 <description>
4496 Callbacks are only reported when the object is an instance of
4497 this class.
4498 Objects which are instances of a subclass of <code>klass</code>
4499 are not reported.
4500 If <code>klass</code> is an interface, no objects are reported.
4501 This applies to both the object and primitive callbacks.
4502 </description>
4503 </param>
4504 <param id="initial_object">
4505 <ptrtype>
4506 <jobject/>
4507 <nullok>references are followed from the heap roots</nullok>
4508 </ptrtype>
4509 <description>
4510 The object to follow
4511 </description>
4512 </param>
4513 <param id="callbacks">
4514 <inptr>
4515 <struct>jvmtiHeapCallbacks</struct>
4516 </inptr>
4517 <description>
4518 Structure defining the set of callback functions.
4519 </description>
4520 </param>
4521 <param id="user_data">
4522 <inbuf>
4523 <void/>
4524 <nullok><code>NULL</code> is passed as the user supplied data</nullok>
4525 </inbuf>
4526 <description>
4527 User supplied data to be passed to the callback.
4528 </description>
4529 </param>
4530 </parameters>
4531 <errors>
4532 <error id="JVMTI_ERROR_INVALID_CLASS">
4533 <paramlink id="klass"/> is not a valid class.
4534 </error>
4535 <error id="JVMTI_ERROR_INVALID_OBJECT">
4536 <paramlink id="initial_object"/> is not a valid object.
4537 </error>
4538 </errors>
4539 </function>
4540
4541
4542 <function id="IterateThroughHeap" num="116" since="1.1">
4543 <synopsis>Iterate Through Heap</synopsis>
4544 <description>
4545 Initiate an iteration over all objects in the heap.
4546 This includes both reachable and
4547 unreachable objects. Objects are visited in no particular order.
4548 <p/>
4549 Heap objects are reported by invoking the agent supplied
4550 callback function <functionlink id="jvmtiHeapIterationCallback"/>.
4551 References between objects are not reported.
4552 If only reachable objects are desired, or if object reference information
4553 is needed, use <functionlink id="FollowReferences"/>.
4554 <p/>
4555 This function can also be used to examine primitive (non-object) values.
4556 The primitive value of an array or String
4557 is reported after the object has been visited;
4558 it is reported by invoking the agent supplied callback function
4559 <functionlink id="jvmtiArrayPrimitiveValueCallback"/> or
4560 <functionlink id="jvmtiStringPrimitiveValueCallback"/>.
4561 A primitive field
4562 is reported after the object with that field is visited;
4563 it is reported by invoking the agent supplied
4564 callback function
4565 <functionlink id="jvmtiPrimitiveFieldCallback"/>.
4566 <p/>
4567 Unless the iteration is aborted by the
4568 <datalink id="jvmtiHeapVisitControl">Heap Visit Control Flags</datalink>
4569 returned by a callback, all objects in the heap are visited.
4570 Whether a callback is provided or is <code>NULL</code> only determines
4571 whether the callback will be invoked, it does not influence
4572 which objects are visited nor does it influence whether other callbacks
4573 will be invoked.
4574 The <datalink id="jvmtiHeapFilter">heap filter flags</datalink>
4575 and <paramlink id="klass"/> provided as parameters to this function
4576 do not control which objects are visited but they do control which
4577 objects and primitive values are reported by the callbacks.
4578 For example, if the only callback that was set is
4579 <paramlink id="array_primitive_value_callback"/> and <code>klass</code>
4580 is set to the array of bytes class, then only arrays of byte will be
4581 reported. The table below summarizes this (contrast this with
4582 <functionlink id="FollowReferences"/>):
4583 <p/>
4584 <table>
4585 <tr>
4586 <th/>
4587 <th>
4588 Controls objects visited
4589 </th>
4590 <th>
4591 Controls objects reported
4592 </th>
4593 <th>
4594 Controls primitives reported
4595 </th>
4596 </tr>
4597 <tr>
4598 <th align="left">
4599 the
4600 <datalink id="jvmtiHeapVisitControl">Heap Visit Control Flags</datalink>
4601 returned by <functionlink id="jvmtiHeapIterationCallback"/>
4602 </th>
4603 <td>
4604 No<br/>(unless they abort the iteration)
4605 </td>
4606 <td>
4607 No<br/>(unless they abort the iteration)
4608 </td>
4609 <td>
4610 No<br/>(unless they abort the iteration)
4611 </td>
4612 </tr>
4613 <tr>
4614 <th align="left">
4615 <fieldlink id="object_callback" struct="jvmtiHeapCallbacks"/>
4616 in <paramlink id="callbacks"/> set
4617 </th>
4618 <td>
4619 No
4620 </td>
4621 <td>
4622 <b>Yes</b>
4623 </td>
4624 <td>
4625 No
4626 </td>
4627 </tr>
4628 <tr>
4629 <th align="left">
4630 <paramlink id="heap_filter"/>
4631 </th>
4632 <td>
4633 No
4634 </td>
4635 <td>
4636 <b>Yes</b>
4637 </td>
4638 <td>
4639 <b>Yes</b>
4640 </td>
4641 </tr>
4642 <tr>
4643 <th align="left">
4644 <paramlink id="klass"/>
4645 </th>
4646 <td>
4647 No
4648 </td>
4649 <td>
4650 <b>Yes</b>
4651 </td>
4652 <td>
4653 <b>Yes</b>
4654 </td>
4655 </tr>
4656 </table>
4657 <p/>
4658 During the execution of this function the state of the heap
4659 does not change: no objects are allocated, no objects are
4660 garbage collected, and the state of objects (including
4661 held values) does not change.
4662 As a result, threads executing Java
4663 programming language code, threads attempting to resume the
4664 execution of Java programming language code, and threads
4665 attempting to execute JNI functions are typically stalled.
4666 </description>
4667 <origin>new</origin>
4668 <capabilities>
4669 <required id="can_tag_objects"></required>
4670 </capabilities>
4671 <parameters>
4672 <param id="heap_filter">
4673 <jint/>
4674 <description>
4675 This bit vector of
4676 <datalink id="jvmtiHeapFilter">heap filter flags</datalink>.
4677 restricts the objects for which the callback function is called.
4678 This applies to both the object and primitive callbacks.
4679 </description>
4680 </param>
4681 <param id="klass">
4682 <ptrtype>
4683 <jclass/>
4684 <nullok>callbacks are not limited to instances of a particular class</nullok>
4685 </ptrtype>
4686 <description>
4687 Callbacks are only reported when the object is an instance of
4688 this class.
4689 Objects which are instances of a subclass of <code>klass</code>
4690 are not reported.
4691 If <code>klass</code> is an interface, no objects are reported.
4692 This applies to both the object and primitive callbacks.
4693 </description>
4694 </param>
4695 <param id="callbacks">
4696 <inptr>
4697 <struct>jvmtiHeapCallbacks</struct>
4698 </inptr>
4699 <description>
4700 Structure defining the set callback functions.
4701 </description>
4702 </param>
4703 <param id="user_data">
4704 <inbuf>
4705 <void/>
4706 <nullok><code>NULL</code> is passed as the user supplied data</nullok>
4707 </inbuf>
4708 <description>
4709 User supplied data to be passed to the callback.
4710 </description>
4711 </param>
4712 </parameters>
4713 <errors>
4714 <error id="JVMTI_ERROR_INVALID_CLASS">
4715 <paramlink id="klass"/> is not a valid class.
4716 </error>
4717 </errors>
4718 </function>
4719
4720 <function id="GetTag" phase="start" num="106">
4721 <synopsis>Get Tag</synopsis>
4722 <description>
4723 Retrieve the tag associated with an object.
4724 The tag is a long value typically used to store a
4725 unique identifier or pointer to object information.
4726 The tag is set with
4727 <functionlink id="SetTag"></functionlink>.
4728 Objects for which no tags have been set return a
4729 tag value of zero.
4730 </description>
4731 <origin>new</origin>
4732 <capabilities>
4733 <required id="can_tag_objects"></required>
4734 </capabilities>
4735 <parameters>
4736 <param id="object">
4737 <jobject/>
4738 <description>
4739 The object whose tag is to be retrieved.
4740 </description>
4741 </param>
4742 <param id="tag_ptr">
4743 <outptr><jlong/></outptr>
4744 <description>
4745 On return, the referenced long is set to the value
4746 of the tag.
4747 </description>
4748 </param>
4749 </parameters>
4750 <errors>
4751 </errors>
4752 </function>
4753
4754 <function id="SetTag" phase="start" num="107">
4755 <synopsis>Set Tag</synopsis>
4756 <description>
4757 Set the tag associated with an object.
4758 The tag is a long value typically used to store a
4759 unique identifier or pointer to object information.
4760 The tag is visible with
4761 <functionlink id="GetTag"></functionlink>.
4762 </description>
4763 <origin>new</origin>
4764 <capabilities>
4765 <required id="can_tag_objects"></required>
4766 </capabilities>
4767 <parameters>
4768 <param id="object">
4769 <jobject/>
4770 <description>
4771 The object whose tag is to be set.
4772 </description>
4773 </param>
4774 <param id="tag">
4775 <jlong/>
4776 <description>
4777 The new value of the tag.
4778 </description>
4779 </param>
4780 </parameters>
4781 <errors>
4782 </errors>
4783 </function>
4784
4785 <function id="GetObjectsWithTags" num="114">
4786 <synopsis>Get Objects With Tags</synopsis>
4787 <description>
4788 Return objects in the heap with the specified tags.
4789 The format is parallel arrays of objects and tags.
4790 </description>
4791 <origin>new</origin>
4792 <capabilities>
4793 <required id="can_tag_objects"></required>
4794 </capabilities>
4795 <parameters>
4796 <param id="tag_count">
4797 <jint min="0"/>
4798 <description>
4799 Number of tags to scan for.
4800 </description>
4801 </param>
4802 <param id="tags">
4803 <inbuf incount="tag_count">
4804 <jlong/>
4805 </inbuf>
4806 <description>
4807 Scan for objects with these tags.
4808 Zero is not permitted in this array.
4809 </description>
4810 </param>
4811 <param id="count_ptr">
4812 <outptr>
4813 <jint/>
4814 </outptr>
4815 <description>
4816 Return the number of objects with any of the tags
4817 in <paramlink id="tags"/>.
4818 </description>
4819 </param>
4820 <param id="object_result_ptr">
4821 <allocbuf outcount="count_ptr">
4822 <jobject/>
4823 <nullok>this information is not returned</nullok>
4824 </allocbuf>
4825 <description>
4826 Returns the array of objects with any of the tags
4827 in <paramlink id="tags"/>.
4828 </description>
4829 </param>
4830 <param id="tag_result_ptr">
4831 <allocbuf outcount="count_ptr">
4832 <jlong/>
4833 <nullok>this information is not returned</nullok>
4834 </allocbuf>
4835 <description>
4836 For each object in <paramlink id="object_result_ptr"/>,
4837 return the tag at the corresponding index.
4838 </description>
4839 </param>
4840 </parameters>
4841 <errors>
4842 <error id="JVMTI_ERROR_ILLEGAL_ARGUMENT">
4843 Zero is present in <paramlink id="tags"></paramlink>.
4844 </error>
4845 </errors>
4846 </function>
4847
4848 <function id="ForceGarbageCollection" num="108">
4849 <synopsis>Force Garbage Collection</synopsis>
4850 <description>
4851 Force the VM to perform a garbage collection.
4852 The garbage collection is as complete as possible.
4853 This function does not cause finalizers to be run.
4854 This function does not return until the garbage collection
4855 is finished.
4856 <p/>
4857 Although garbage collection is as complete
4858 as possible there is no guarantee that all
4859 <eventlink id="ObjectFree"/>
4860 events will have been
4861 sent by the time that this function
4862 returns. In particular, an object may be
4863 prevented from being freed because it
4864 is awaiting finalization.
4865 </description>
4866 <origin>new</origin>
4867 <capabilities>
4868 </capabilities>
4869 <parameters>
4870 </parameters>
4871 <errors>
4872 </errors>
4873 </function>
4874
4875
4876 </category>
4877
4878 <category id="Heap_1_0" label="Heap (1.0)">
4879 <intro>
4880 <b>
4881 These functions and data types were introduced in the original
4882 <jvmti/> version 1.0 and have been superseded by more
4883 </b>
4884 <internallink id="Heap"><b>powerful and flexible versions</b></internallink>
4885 <b>
4886 which:
4887 </b>
4888 <ul>
4889 <li>
4890 <b>
4891 Allow access to primitive values (the value of Strings, arrays,
4892 and primitive fields)
4893 </b>
4894 </li>
4895 <li>
4896 <b>
4897 Allow the tag of the referrer to be set, thus enabling more
4898 efficient localized reference graph building
4899 </b>
4900 </li>
4901 <li>
4902 <b>
4903 Provide more extensive filtering abilities
4904 </b>
4905 </li>
4906 <li>
4907 <b>
4908 Are extensible, allowing their abilities to grow in future versions of <jvmti/>
4909 </b>
4910 </li>
4911 </ul>
4912 <p/>
4913 <b>Please use the </b>
4914 <internallink id="Heap"><b>current Heap functions</b></internallink>.
4915 <p/>
4916 <constants id="jvmtiHeapObjectFilter" label="Heap Object Filter Enumeration" kind="enum">
4917 <constant id="JVMTI_HEAP_OBJECT_TAGGED" num="1">
4918 Tagged objects only.
4919 </constant>
4920 <constant id="JVMTI_HEAP_OBJECT_UNTAGGED" num="2">
4921 Untagged objects only.
4922 </constant>
4923 <constant id="JVMTI_HEAP_OBJECT_EITHER" num="3">
4924 Either tagged or untagged objects.
4925 </constant>
4926 </constants>
4927
4928 <constants id="jvmtiHeapRootKind" label="Heap Root Kind Enumeration" kind="enum">
4929 <constant id="JVMTI_HEAP_ROOT_JNI_GLOBAL" num="1">
4930 JNI global reference.
4931 </constant>
4932 <constant id="JVMTI_HEAP_ROOT_SYSTEM_CLASS" num="2">
4933 System class.
4934 </constant>
4935 <constant id="JVMTI_HEAP_ROOT_MONITOR" num="3">
4936 Monitor.
4937 </constant>
4938 <constant id="JVMTI_HEAP_ROOT_STACK_LOCAL" num="4">
4939 Stack local.
4940 </constant>
4941 <constant id="JVMTI_HEAP_ROOT_JNI_LOCAL" num="5">
4942 JNI local reference.
4943 </constant>
4944 <constant id="JVMTI_HEAP_ROOT_THREAD" num="6">
4945 Thread.
4946 </constant>
4947 <constant id="JVMTI_HEAP_ROOT_OTHER" num="7">
4948 Other.
4949 </constant>
4950 </constants>
4951
4952 <constants id="jvmtiObjectReferenceKind" label="Object Reference Enumeration" kind="enum">
4953 <constant id="JVMTI_REFERENCE_CLASS" num="1">
4954 Reference from an object to its class.
4955 </constant>
4956 <constant id="JVMTI_REFERENCE_FIELD" num="2">
4957 Reference from an object to the value of one of its instance fields.
4958 For references of this kind the <code>referrer_index</code>
4959 parameter to the <internallink id="jvmtiObjectReferenceCallback">
4960 jvmtiObjectReferenceCallback</internallink> is the index of the
4961 the instance field. The index is based on the order of all the
4962 object's fields. This includes all fields of the directly declared
4963 static and instance fields in the class, and includes all fields (both
4964 public and private) fields declared in superclasses and superinterfaces.
4965 The index is thus calculated by summing the index of the field in the directly
4966 declared class (see <functionlink id="GetClassFields"/>), with the total
4967 number of fields (both public and private) declared in all superclasses
4968 and superinterfaces. The index starts at zero.
4969 </constant>
4970 <constant id="JVMTI_REFERENCE_ARRAY_ELEMENT" num="3">
4971 Reference from an array to one of its elements.
4972 For references of this kind the <code>referrer_index</code>
4973 parameter to the <internallink id="jvmtiObjectReferenceCallback">
4974 jvmtiObjectReferenceCallback</internallink> is the array index.
4975 </constant>
4976 <constant id="JVMTI_REFERENCE_CLASS_LOADER" num="4">
4977 Reference from a class to its class loader.
4978 </constant>
4979 <constant id="JVMTI_REFERENCE_SIGNERS" num="5">
4980 Reference from a class to its signers array.
4981 </constant>
4982 <constant id="JVMTI_REFERENCE_PROTECTION_DOMAIN" num="6">
4983 Reference from a class to its protection domain.
4984 </constant>
4985 <constant id="JVMTI_REFERENCE_INTERFACE" num="7">
4986 Reference from a class to one of its interfaces.
4987 </constant>
4988 <constant id="JVMTI_REFERENCE_STATIC_FIELD" num="8">
4989 Reference from a class to the value of one of its static fields.
4990 For references of this kind the <code>referrer_index</code>
4991 parameter to the <internallink id="jvmtiObjectReferenceCallback">
4992 jvmtiObjectReferenceCallback</internallink> is the index of the
4993 the static field. The index is based on the order of all the
4994 object's fields. This includes all fields of the directly declared
4995 static and instance fields in the class, and includes all fields (both
4996 public and private) fields declared in superclasses and superinterfaces.
4997 The index is thus calculated by summing the index of the field in the directly
4998 declared class (see <functionlink id="GetClassFields"/>), with the total
4999 number of fields (both public and private) declared in all superclasses
5000 and superinterfaces. The index starts at zero.
5001 Note: this definition differs from that in the <jvmti/> 1.0 Specification.
5002 <rationale>No known implementations used the 1.0 definition.</rationale>
5003 </constant>
5004 <constant id="JVMTI_REFERENCE_CONSTANT_POOL" num="9">
5005 Reference from a class to a resolved entry in the constant pool.
5006 For references of this kind the <code>referrer_index</code>
5007 parameter to the <internallink id="jvmtiObjectReferenceCallback">
5008 jvmtiObjectReferenceCallback</internallink> is the index into
5009 constant pool table of the class, starting at 1. See the
5010 <vmspeclink id="ClassFile.doc.html#20080"
5011 name="Constant Pool section"/>
5012 </constant>
5013 </constants>
5014
5015 <constants id="jvmtiIterationControl" label="Iteration Control Enumeration" kind="enum">
5016 <constant id="JVMTI_ITERATION_CONTINUE" num="1">
5017 Continue the iteration.
5018 If this is a reference iteration, follow the references of this object.
5019 </constant>
5020 <constant id="JVMTI_ITERATION_IGNORE" num="2">
5021 Continue the iteration.
5022 If this is a reference iteration, ignore the references of this object.
5023 </constant>
5024 <constant id="JVMTI_ITERATION_ABORT" num="0">
5025 Abort the iteration.
5026 </constant>
5027 </constants>
5028 </intro>
5029
5030 <callback id="jvmtiHeapObjectCallback">
5031 <enum>jvmtiIterationControl</enum>
5032 <synopsis>Heap Object Callback</synopsis>
5033 <description>
5034 Agent supplied callback function.
5035 Describes (but does not pass in) an object in the heap.
5036 <p/>
5037 Return value should be <code>JVMTI_ITERATION_CONTINUE</code> to continue iteration,
5038 or <code>JVMTI_ITERATION_ABORT</code> to stop iteration.
5039 <p/>
5040 See the <internallink id="heapCallbacks">heap callback
5041 function restrictions</internallink>.
5042 </description>
5043 <parameters>
5044 <param id="class_tag">
5045 <jlong/>
5046 <description>
5047 The tag of the class of object (zero if the class is not tagged).
5048 If the object represents a runtime class,
5049 the <code>class_tag</code> is the tag
5050 associated with <code>java.lang.Class</code>
5051 (zero if <code>java.lang.Class</code> is not tagged).
5052 </description>
5053 </param>
5054 <param id="size">
5055 <jlong/>
5056 <description>
5057 Size of the object (in bytes). See <functionlink id="GetObjectSize"/>.
5058 </description>
5059 </param>
5060 <param id="tag_ptr">
5061 <outptr><jlong/></outptr>
5062 <description>
5063 The object tag value, or zero if the object is not tagged.
5064 To set the tag value to be associated with the object
5065 the agent sets the <code>jlong</code> pointed to by the parameter.
5066 </description>
5067 </param>
5068 <param id="user_data">
5069 <outptr><void/></outptr>
5070 <description>
5071 The user supplied data that was passed into the iteration function.
5072 </description>
5073 </param>
5074 </parameters>
5075 </callback>
5076
5077 <callback id="jvmtiHeapRootCallback">
5078 <enum>jvmtiIterationControl</enum>
5079 <synopsis>Heap Root Object Callback</synopsis>
5080 <description>
5081 Agent supplied callback function.
5082 Describes (but does not pass in) an object that is a root for the purposes
5083 of garbage collection.
5084 <p/>
5085 Return value should be <code>JVMTI_ITERATION_CONTINUE</code> to continue iteration,
5086 <code>JVMTI_ITERATION_IGNORE</code> to continue iteration without pursuing
5087 references from referree object or <code>JVMTI_ITERATION_ABORT</code> to stop iteration.
5088 <p/>
5089 See the <internallink id="heapCallbacks">heap callback
5090 function restrictions</internallink>.
5091 </description>
5092 <parameters>
5093 <param id="root_kind">
5094 <enum>jvmtiHeapRootKind</enum>
5095 <description>
5096 The kind of heap root.
5097 </description>
5098 </param>
5099 <param id="class_tag">
5100 <jlong/>
5101 <description>
5102 The tag of the class of object (zero if the class is not tagged).
5103 If the object represents a runtime class, the <code>class_tag</code> is the tag
5104 associated with <code>java.lang.Class</code>
5105 (zero if <code>java.lang.Class</code> is not tagged).
5106 </description>
5107 </param>
5108 <param id="size">
5109 <jlong/>
5110 <description>
5111 Size of the object (in bytes). See <functionlink id="GetObjectSize"/>.
5112 </description>
5113 </param>
5114 <param id="tag_ptr">
5115 <outptr><jlong/></outptr>
5116 <description>
5117 The object tag value, or zero if the object is not tagged.
5118 To set the tag value to be associated with the object
5119 the agent sets the <code>jlong</code> pointed to by the parameter.
5120 </description>
5121 </param>
5122 <param id="user_data">
5123 <outptr><void/></outptr>
5124 <description>
5125 The user supplied data that was passed into the iteration function.
5126 </description>
5127 </param>
5128 </parameters>
5129 </callback>
5130
5131 <callback id="jvmtiStackReferenceCallback">
5132 <enum>jvmtiIterationControl</enum>
5133 <synopsis>Stack Reference Object Callback</synopsis>
5134 <description>
5135 Agent supplied callback function.
5136 Describes (but does not pass in) an object on the stack that is a root for
5137 the purposes of garbage collection.
5138 <p/>
5139 Return value should be <code>JVMTI_ITERATION_CONTINUE</code> to continue iteration,
5140 <code>JVMTI_ITERATION_IGNORE</code> to continue iteration without pursuing
5141 references from referree object or <code>JVMTI_ITERATION_ABORT</code> to stop iteration.
5142 <p/>
5143 See the <internallink id="heapCallbacks">heap callback
5144 function restrictions</internallink>.
5145 </description>
5146 <parameters>
5147 <param id="root_kind">
5148 <enum>jvmtiHeapRootKind</enum>
5149 <description>
5150 The kind of root (either <code>JVMTI_HEAP_ROOT_STACK_LOCAL</code> or
5151 <code>JVMTI_HEAP_ROOT_JNI_LOCAL</code>).
5152 </description>
5153 </param>
5154 <param id="class_tag">
5155 <jlong/>
5156 <description>
5157 The tag of the class of object (zero if the class is not tagged).
5158 If the object represents a runtime class, the <code>class_tag</code> is the tag
5159 associated with <code>java.lang.Class</code>
5160 (zero if <code>java.lang.Class</code> is not tagged).
5161 </description>
5162 </param>
5163 <param id="size">
5164 <jlong/>
5165 <description>
5166 Size of the object (in bytes). See <functionlink id="GetObjectSize"/>.
5167 </description>
5168 </param>
5169 <param id="tag_ptr">
5170 <outptr><jlong/></outptr>
5171 <description>
5172 The object tag value, or zero if the object is not tagged.
5173 To set the tag value to be associated with the object
5174 the agent sets the <code>jlong</code> pointed to by the parameter.
5175 </description>
5176 </param>
5177 <param id="thread_tag">
5178 <jlong/>
5179 <description>
5180 The tag of the thread corresponding to this stack, zero if not tagged.
5181 </description>
5182 </param>
5183 <param id="depth">
5184 <jint/>
5185 <description>
5186 The depth of the frame.
5187 </description>
5188 </param>
5189 <param id="method">
5190 <jmethodID/>
5191 <description>
5192 The method executing in this frame.
5193 </description>
5194 </param>
5195 <param id="slot">
5196 <jint/>
5197 <description>
5198 The slot number.
5199 </description>
5200 </param>
5201 <param id="user_data">
5202 <outptr><void/></outptr>
5203 <description>
5204 The user supplied data that was passed into the iteration function.
5205 </description>
5206 </param>
5207 </parameters>
5208 </callback>
5209
5210 <callback id="jvmtiObjectReferenceCallback">
5211 <enum>jvmtiIterationControl</enum>
5212 <synopsis>Object Reference Callback</synopsis>
5213 <description>
5214 Agent supplied callback function.
5215 Describes a reference from an object (the referrer) to another object
5216 (the referree).
5217 <p/>
5218 Return value should be <code>JVMTI_ITERATION_CONTINUE</code> to continue iteration,
5219 <code>JVMTI_ITERATION_IGNORE</code> to continue iteration without pursuing
5220 references from referree object or <code>JVMTI_ITERATION_ABORT</code> to stop iteration.
5221 <p/>
5222 See the <internallink id="heapCallbacks">heap callback
5223 function restrictions</internallink>.
5224 </description>
5225 <parameters>
5226 <param id="reference_kind">
5227 <enum>jvmtiObjectReferenceKind</enum>
5228 <description>
5229 The type of reference.
5230 </description>
5231 </param>
5232 <param id="class_tag">
5233 <jlong/>
5234 <description>
5235 The tag of the class of referree object (zero if the class is not tagged).
5236 If the referree object represents a runtime class,
5237 the <code>class_tag</code> is the tag
5238 associated with <code>java.lang.Class</code>
5239 (zero if <code>java.lang.Class</code> is not tagged).
5240 </description>
5241 </param>
5242 <param id="size">
5243 <jlong/>
5244 <description>
5245 Size of the referree object (in bytes).
5246 See <functionlink id="GetObjectSize"/>.
5247 </description>
5248 </param>
5249 <param id="tag_ptr">
5250 <outptr><jlong/></outptr>
5251 <description>
5252 The referree object tag value, or zero if the object is not
5253 tagged.
5254 To set the tag value to be associated with the object
5255 the agent sets the <code>jlong</code> pointed to by the parameter.
5256 </description>
5257 </param>
5258 <param id="referrer_tag">
5259 <jlong/>
5260 <description>
5261 The tag of the referrer object, or zero if the referrer
5262 object is not tagged.
5263 </description>
5264 </param>
5265 <param id="referrer_index">
5266 <jint/>
5267 <description>
5268 For references of type <code>JVMTI_REFERENCE_FIELD</code> or
5269 <code>JVMTI_REFERENCE_STATIC_FIELD</code> the index
5270 of the field in the referrer object. The index is based on the
5271 order of all the object's fields - see <internallink
5272 id="JVMTI_REFERENCE_FIELD">JVMTI_REFERENCE_FIELD</internallink>
5273 or <internallink
5274 id="JVMTI_REFERENCE_STATIC_FIELD">JVMTI_REFERENCE_STATIC_FIELD
5275 </internallink> for further description.
5276 <p/>
5277 For references of type <code>JVMTI_REFERENCE_ARRAY_ELEMENT</code>
5278 the array index - see <internallink id="JVMTI_REFERENCE_ARRAY_ELEMENT">
5279 JVMTI_REFERENCE_ARRAY_ELEMENT</internallink> for further description.
5280 <p/>
5281 For references of type <code>JVMTI_REFERENCE_CONSTANT_POOL</code>
5282 the index into the constant pool of the class - see
5283 <internallink id="JVMTI_REFERENCE_CONSTANT_POOL">
5284 JVMTI_REFERENCE_CONSTANT_POOL</internallink> for further
5285 description.
5286 <p/>
5287 For references of other kinds the <code>referrer_index</code> is
5288 <code>-1</code>.
5289 </description>
5290 </param>
5291 <param id="user_data">
5292 <outptr><void/></outptr>
5293 <description>
5294 The user supplied data that was passed into the iteration function.
5295 </description>
5296 </param>
5297 </parameters>
5298 </callback>
5299
5300 <function id="IterateOverObjectsReachableFromObject" num="109">
5301 <synopsis>Iterate Over Objects Reachable From Object</synopsis>
5302 <description>
5303 This function iterates over all objects that are directly
5304 and indirectly reachable from the specified object.
5305 For each object <i>A</i> (known
5306 as the referrer) with a reference to object <i>B</i> the specified
5307 callback function is called to describe the object reference.
5308 The callback is called exactly once for each reference from a referrer;
5309 this is true even if there are reference cycles or multiple paths to
5310 the referrer.
5311 There may be more than one reference between a referrer and a referree,
5312 These may be distinguished by the
5313 <datalink id="jvmtiObjectReferenceCallback.reference_kind"></datalink> and
5314 <datalink id="jvmtiObjectReferenceCallback.referrer_index"></datalink>.
5315 The callback for an object will always occur after the callback for
5316 its referrer.
5317 <p/>
5318 See <functionlink id="FollowReferences"/> for the object
5319 references which are reported.
5320 <p/>
5321 During the execution of this function the state of the heap
5322 does not change: no objects are allocated, no objects are
5323 garbage collected, and the state of objects (including
5324 held values) does not change.
5325 As a result, threads executing Java
5326 programming language code, threads attempting to resume the
5327 execution of Java programming language code, and threads
5328 attempting to execute JNI functions are typically stalled.
5329 </description>
5330 <origin>new</origin>
5331 <capabilities>
5332 <required id="can_tag_objects"></required>
5333 </capabilities>
5334 <parameters>
5335 <param id="object">
5336 <jobject/>
5337 <description>
5338 The object
5339 </description>
5340 </param>
5341 <param id="object_reference_callback">
5342 <ptrtype>
5343 <struct>jvmtiObjectReferenceCallback</struct>
5344 </ptrtype>
5345 <description>
5346 The callback to be called to describe each
5347 object reference.
5348 </description>
5349 </param>
5350 <param id="user_data">
5351 <inbuf>
5352 <void/>
5353 <nullok><code>NULL</code> is passed as the user supplied data</nullok>
5354 </inbuf>
5355 <description>
5356 User supplied data to be passed to the callback.
5357 </description>
5358 </param>
5359 </parameters>
5360 <errors>
5361 </errors>
5362 </function>
5363
5364 <function id="IterateOverReachableObjects" num="110">
5365 <synopsis>Iterate Over Reachable Objects</synopsis>
5366 <description>
5367 This function iterates over the root objects and all objects that
5368 are directly and indirectly reachable from the root objects.
5369 The root objects comprise the set of system classes,
5370 JNI globals, references from thread stacks, and other objects used as roots
5371 for the purposes of garbage collection.
5372 <p/>
5373 For each root the <paramlink id="heap_root_callback"></paramlink>
5374 or <paramlink id="stack_ref_callback"></paramlink> callback is called.
5375 An object can be a root object for more than one reason and in that case
5376 the appropriate callback is called for each reason.
5377 <p/>
5378 For each object reference the <paramlink id="object_ref_callback"></paramlink>
5379 callback function is called to describe the object reference.
5380 The callback is called exactly once for each reference from a referrer;
5381 this is true even if there are reference cycles or multiple paths to
5382 the referrer.
5383 There may be more than one reference between a referrer and a referree,
5384 These may be distinguished by the
5385 <datalink id="jvmtiObjectReferenceCallback.reference_kind"></datalink> and
5386 <datalink id="jvmtiObjectReferenceCallback.referrer_index"></datalink>.
5387 The callback for an object will always occur after the callback for
5388 its referrer.
5389 <p/>
5390 See <functionlink id="FollowReferences"/> for the object
5391 references which are reported.
5392 <p/>
5393 Roots are always reported to the profiler before any object references
5394 are reported. In other words, the <paramlink id="object_ref_callback"></paramlink>
5395 callback will not be called until the appropriate callback has been called
5396 for all roots. If the <paramlink id="object_ref_callback"></paramlink> callback is
5397 specified as <code>NULL</code> then this function returns after
5398 reporting the root objects to the profiler.
5399 <p/>
5400 During the execution of this function the state of the heap
5401 does not change: no objects are allocated, no objects are
5402 garbage collected, and the state of objects (including
5403 held values) does not change.
5404 As a result, threads executing Java
5405 programming language code, threads attempting to resume the
5406 execution of Java programming language code, and threads
5407 attempting to execute JNI functions are typically stalled.
5408 </description>
5409 <origin>new</origin>
5410 <capabilities>
5411 <required id="can_tag_objects"></required>
5412 </capabilities>
5413 <parameters>
5414 <param id="heap_root_callback">
5415 <ptrtype>
5416 <struct>jvmtiHeapRootCallback</struct>
5417 <nullok>do not report heap roots</nullok>
5418 </ptrtype>
5419 <description>
5420 The callback function to be called for each heap root of type
5421 <code>JVMTI_HEAP_ROOT_JNI_GLOBAL</code>,
5422 <code>JVMTI_HEAP_ROOT_SYSTEM_CLASS</code>,
5423 <code>JVMTI_HEAP_ROOT_MONITOR</code>,
5424 <code>JVMTI_HEAP_ROOT_THREAD</code>, or
5425 <code>JVMTI_HEAP_ROOT_OTHER</code>.
5426 </description>
5427 </param>
5428 <param id="stack_ref_callback">
5429 <ptrtype>
5430 <struct>jvmtiStackReferenceCallback</struct>
5431 <nullok>do not report stack references</nullok>
5432 </ptrtype>
5433 <description>
5434 The callback function to be called for each heap root of
5435 <code>JVMTI_HEAP_ROOT_STACK_LOCAL</code> or
5436 <code>JVMTI_HEAP_ROOT_JNI_LOCAL</code>.
5437 </description>
5438 </param>
5439 <param id="object_ref_callback">
5440 <ptrtype>
5441 <struct>jvmtiObjectReferenceCallback</struct>
5442 <nullok>do not follow references from the root objects</nullok>
5443 </ptrtype>
5444 <description>
5445 The callback function to be called for each object reference.
5446 </description>
5447 </param>
5448 <param id="user_data">
5449 <inbuf>
5450 <void/>
5451 <nullok><code>NULL</code> is passed as the user supplied data</nullok>
5452 </inbuf>
5453 <description>
5454 User supplied data to be passed to the callback.
5455 </description>
5456 </param>
5457 </parameters>
5458 <errors>
5459 </errors>
5460 </function>
5461
5462 <function id="IterateOverHeap" num="111">
5463 <synopsis>Iterate Over Heap</synopsis>
5464 <description>
5465 Iterate over all objects in the heap. This includes both reachable and
5466 unreachable objects.
5467 <p/>
5468 The <paramlink id="object_filter"></paramlink> parameter indicates the
5469 objects for which the callback function is called. If this parameter
5470 is <code>JVMTI_HEAP_OBJECT_TAGGED</code> then the callback will only be
5471 called for every object that is tagged. If the parameter is
5472 <code>JVMTI_HEAP_OBJECT_UNTAGGED</code> then the callback will only be
5473 for objects that are not tagged. If the parameter
5474 is <code>JVMTI_HEAP_OBJECT_EITHER</code> then the callback will be
5475 called for every object in the heap, irrespective of whether it is
5476 tagged or not.
5477 <p/>
5478 During the execution of this function the state of the heap
5479 does not change: no objects are allocated, no objects are
5480 garbage collected, and the state of objects (including
5481 held values) does not change.
5482 As a result, threads executing Java
5483 programming language code, threads attempting to resume the
5484 execution of Java programming language code, and threads
5485 attempting to execute JNI functions are typically stalled.
5486 </description>
5487 <origin>new</origin>
5488 <capabilities>
5489 <required id="can_tag_objects"></required>
5490 </capabilities>
5491 <parameters>
5492 <param id="object_filter">
5493 <enum>jvmtiHeapObjectFilter</enum>
5494 <description>
5495 Indicates the objects for which the callback function is called.
5496 </description>
5497 </param>
5498 <param id="heap_object_callback">
5499 <ptrtype>
5500 <struct>jvmtiHeapObjectCallback</struct>
5501 </ptrtype>
5502 <description>
5503 The iterator function to be called for each
5504 object matching the <paramlink id="object_filter"/>.
5505 </description>
5506 </param>
5507 <param id="user_data">
5508 <inbuf>
5509 <void/>
5510 <nullok><code>NULL</code> is passed as the user supplied data</nullok>
5511 </inbuf>
5512 <description>
5513 User supplied data to be passed to the callback.
5514 </description>
5515 </param>
5516 </parameters>
5517 <errors>
5518 </errors>
5519 </function>
5520
5521 <function id="IterateOverInstancesOfClass" num="112">
5522 <synopsis>Iterate Over Instances Of Class</synopsis>
5523 <description>
5524 Iterate over all objects in the heap that are instances of the specified class.
5525 This includes direct instances of the specified class and
5526 instances of all subclasses of the specified class.
5527 This includes both reachable and unreachable objects.
5528 <p/>
5529 The <paramlink id="object_filter"></paramlink> parameter indicates the
5530 objects for which the callback function is called. If this parameter
5531 is <code>JVMTI_HEAP_OBJECT_TAGGED</code> then the callback will only be
5532 called for every object that is tagged. If the parameter is
5533 <code>JVMTI_HEAP_OBJECT_UNTAGGED</code> then the callback will only be
5534 called for objects that are not tagged. If the parameter
5535 is <code>JVMTI_HEAP_OBJECT_EITHER</code> then the callback will be
5536 called for every object in the heap, irrespective of whether it is
5537 tagged or not.
5538 <p/>
5539 During the execution of this function the state of the heap
5540 does not change: no objects are allocated, no objects are
5541 garbage collected, and the state of objects (including
5542 held values) does not change.
5543 As a result, threads executing Java
5544 programming language code, threads attempting to resume the
5545 execution of Java programming language code, and threads
5546 attempting to execute JNI functions are typically stalled.
5547 </description>
5548 <origin>new</origin>
5549 <capabilities>
5550 <required id="can_tag_objects"></required>
5551 </capabilities>
5552 <parameters>
5553 <param id="klass">
5554 <jclass/>
5555 <description>
5556 Iterate over objects of this class only.
5557 </description>
5558 </param>
5559 <param id="object_filter">
5560 <enum>jvmtiHeapObjectFilter</enum>
5561 <description>
5562 Indicates the objects for which the callback function is called.
5563 </description>
5564 </param>
5565 <param id="heap_object_callback">
5566 <ptrtype>
5567 <struct>jvmtiHeapObjectCallback</struct>
5568 </ptrtype>
5569 <description>
5570 The iterator function to be called for each
5571 <paramlink id="klass"/> instance matching
5572 the <paramlink id="object_filter"/>.
5573 </description>
5574 </param>
5575 <param id="user_data">
5576 <inbuf>
5577 <void/>
5578 <nullok><code>NULL</code> is passed as the user supplied data</nullok>
5579 </inbuf>
5580 <description>
5581 User supplied data to be passed to the callback.
5582 </description>
5583 </param>
5584 </parameters>
5585 <errors>
5586 </errors>
5587 </function>
5588
5589 </category>
5590
5591 <category id="local" label="Local Variable">
5592
5593 <intro>
5594 These functions are used to retrieve or set the value of a local variable.
5595 The variable is identified by the depth of the frame containing its
5596 value and the variable's slot number within that frame.
5597 The mapping of variables to
5598 slot numbers can be obtained with the function
5599 <functionlink id="GetLocalVariableTable"></functionlink>.
5600 </intro>
5601
5602 <function id="GetLocalObject" num="21">
5603 <synopsis>Get Local Variable - Object</synopsis>
5604 <description>
5605 This function can be used to retrieve the value of a local
5606 variable whose type is <code>Object</code> or a subclass of <code>Object</code>.
5607 </description>
5608 <origin>jvmdi</origin>
5609 <capabilities>
5610 <required id="can_access_local_variables"></required>
5611 </capabilities>
5612 <parameters>
5613 <param id="thread">
5614 <jthread null="current" frame="frame"/>
5615 <description>
5616 The thread of the frame containing the variable's value.
5617 </description>
5618 </param>
5619 <param id="depth">
5620 <jframeID thread="thread"/>
5621 <description>
5622 The depth of the frame containing the variable's value.
5623 </description>
5624 </param>
5625 <param id="slot">
5626 <jint/>
5627 <description>
5628 The variable's slot number.
5629 </description>
5630 </param>
5631 <param id="value_ptr">
5632 <outptr><jobject/></outptr>
5633 <description>
5634 On return, points to the variable's value.
5635 </description>
5636 </param>
5637 </parameters>
5638 <errors>
5639 <error id="JVMTI_ERROR_INVALID_SLOT">
5640 Invalid <code>slot</code>.
5641 </error>
5642 <error id="JVMTI_ERROR_TYPE_MISMATCH">
5643 The variable type is not
5644 <code>Object</code> or a subclass of <code>Object</code>.
5645 </error>
5646 <error id="JVMTI_ERROR_OPAQUE_FRAME">
5647 Not a visible frame
5648 </error>
5649 </errors>
5650 </function>
5651
5652 <function id="GetLocalInt" num="22">
5653 <synopsis>Get Local Variable - Int</synopsis>
5654 <description>
5655 This function can be used to retrieve the value of a local
5656 variable whose type is <code>int</code>,
5657 <code>short</code>, <code>char</code>, <code>byte</code>, or
5658 <code>boolean</code>.
5659 </description>
5660 <origin>jvmdi</origin>
5661 <capabilities>
5662 <required id="can_access_local_variables"></required>
5663 </capabilities>
5664 <parameters>
5665 <param id="thread">
5666 <jthread null="current" frame="frame"/>
5667 <description>
5668 The thread of the frame containing the variable's value.
5669 </description>
5670 </param>
5671 <param id="depth">
5672 <jframeID thread="thread"/>
5673 <description>
5674 The depth of the frame containing the variable's value.
5675 </description>
5676 </param>
5677 <param id="slot">
5678 <jint/>
5679 <description>
5680 The variable's slot number.
5681 </description>
5682 </param>
5683 <param id="value_ptr">
5684 <outptr><jint/></outptr>
5685 <description>
5686 On return, points to the variable's value.
5687 </description>
5688 </param>
5689 </parameters>
5690 <errors>
5691 <error id="JVMTI_ERROR_INVALID_SLOT">
5692 Invalid <code>slot</code>.
5693 </error>
5694 <error id="JVMTI_ERROR_TYPE_MISMATCH">
5695 The variable type is not
5696 <code>int</code>, <code>short</code>,
5697 <code>char</code>, <code>byte</code>, or
5698 <code>boolean</code>.
5699 </error>
5700 <error id="JVMTI_ERROR_OPAQUE_FRAME">
5701 Not a visible frame
5702 </error>
5703 </errors>
5704 </function>
5705
5706 <function id="GetLocalLong" num="23">
5707 <synopsis>Get Local Variable - Long</synopsis>
5708 <description>
5709 This function can be used to retrieve the value of a local
5710 variable whose type is <code>long</code>.
5711 </description>
5712 <origin>jvmdi</origin>
5713 <capabilities>
5714 <required id="can_access_local_variables"></required>
5715 </capabilities>
5716 <parameters>
5717 <param id="thread">
5718 <jthread null="current" frame="frame"/>
5719 <description>
5720 The thread of the frame containing the variable's value.
5721 </description>
5722 </param>
5723 <param id="depth">
5724 <jframeID thread="thread"/>
5725 <description>
5726 The depth of the frame containing the variable's value.
5727 </description>
5728 </param>
5729 <param id="slot">
5730 <jint/>
5731 <description>
5732 The variable's slot number.
5733 </description>
5734 </param>
5735 <param id="value_ptr">
5736 <outptr><jlong/></outptr>
5737 <description>
5738 On return, points to the variable's value.
5739 </description>
5740 </param>
5741 </parameters>
5742 <errors>
5743 <error id="JVMTI_ERROR_INVALID_SLOT">
5744 Invalid <code>slot</code>.
5745 </error>
5746 <error id="JVMTI_ERROR_TYPE_MISMATCH">
5747 The variable type is not <code>long</code>.
5748 </error>
5749 <error id="JVMTI_ERROR_OPAQUE_FRAME">
5750 Not a visible frame
5751 </error>
5752 </errors>
5753 </function>
5754
5755 <function id="GetLocalFloat" num="24">
5756 <synopsis>Get Local Variable - Float</synopsis>
5757 <description>
5758 This function can be used to retrieve the value of a local
5759 variable whose type is <code>float</code>.
5760 </description>
5761 <origin>jvmdi</origin>
5762 <capabilities>
5763 <required id="can_access_local_variables"></required>
5764 </capabilities>
5765 <parameters>
5766 <param id="thread">
5767 <jthread null="current" frame="frame"/>
5768 <description>
5769 The thread of the frame containing the variable's value.
5770 </description>
5771 </param>
5772 <param id="depth">
5773 <jframeID thread="thread"/>
5774 <description>
5775 The depth of the frame containing the variable's value.
5776 </description>
5777 </param>
5778 <param id="slot">
5779 <jint/>
5780 <description>
5781 The variable's slot number.
5782 </description>
5783 </param>
5784 <param id="value_ptr">
5785 <outptr><jfloat/></outptr>
5786 <description>
5787 On return, points to the variable's value.
5788 </description>
5789 </param>
5790 </parameters>
5791 <errors>
5792 <error id="JVMTI_ERROR_INVALID_SLOT">
5793 Invalid <code>slot</code>.
5794 </error>
5795 <error id="JVMTI_ERROR_TYPE_MISMATCH">
5796 The variable type is not <code>float</code>.
5797 </error>
5798 <error id="JVMTI_ERROR_OPAQUE_FRAME">
5799 Not a visible frame
5800 </error>
5801 </errors>
5802 </function>
5803
5804 <function id="GetLocalDouble" num="25">
5805 <synopsis>Get Local Variable - Double</synopsis>
5806 <description>
5807 This function can be used to retrieve the value of a local
5808 variable whose type is <code>long</code>.
5809 </description>
5810 <origin>jvmdi</origin>
5811 <capabilities>
5812 <required id="can_access_local_variables"></required>
5813 </capabilities>
5814 <parameters>
5815 <param id="thread">
5816 <jthread null="current" frame="frame"/>
5817 <description>
5818 The thread of the frame containing the variable's value.
5819 </description>
5820 </param>
5821 <param id="depth">
5822 <jframeID thread="thread"/>
5823 <description>
5824 The depth of the frame containing the variable's value.
5825 </description>
5826 </param>
5827 <param id="slot">
5828 <jint/>
5829 <description>
5830 The variable's slot number.
5831 </description>
5832 </param>
5833 <param id="value_ptr">
5834 <outptr><jdouble/></outptr>
5835 <description>
5836 On return, points to the variable's value.
5837 </description>
5838 </param>
5839 </parameters>
5840 <errors>
5841 <error id="JVMTI_ERROR_INVALID_SLOT">
5842 Invalid <code>slot</code>.
5843 </error>
5844 <error id="JVMTI_ERROR_TYPE_MISMATCH">
5845 The variable type is not <code>double</code>.
5846 </error>
5847 <error id="JVMTI_ERROR_OPAQUE_FRAME">
5848 Not a visible frame
5849 </error>
5850 </errors>
5851 </function>
5852
5853 <function id="SetLocalObject" num="26">
5854 <synopsis>Set Local Variable - Object</synopsis>
5855 <description>
5856 This function can be used to set the value of a local
5857 variable whose type is <code>Object</code> or a subclass of <code>Object</code>.
5858 </description>
5859 <origin>jvmdi</origin>
5860 <capabilities>
5861 <required id="can_access_local_variables"></required>
5862 </capabilities>
5863 <parameters>
5864 <param id="thread">
5865 <jthread null="current" frame="frame"/>
5866 <description>
5867 The thread of the frame containing the variable's value.
5868 </description>
5869 </param>
5870 <param id="depth">
5871 <jframeID thread="thread"/>
5872 <description>
5873 The depth of the frame containing the variable's value.
5874 </description>
5875 </param>
5876 <param id="slot">
5877 <jint/>
5878 <description>
5879 The variable's slot number.
5880 </description>
5881 </param>
5882 <param id="value">
5883 <jobject/>
5884 <description>
5885 The new value for the variable.
5886 </description>
5887 </param>
5888 </parameters>
5889 <errors>
5890 <error id="JVMTI_ERROR_INVALID_SLOT">
5891 Invalid <code>slot</code>.
5892 </error>
5893 <error id="JVMTI_ERROR_TYPE_MISMATCH">
5894 The variable type is not
5895 <code>Object</code> or a subclass of <code>Object</code>.
5896 </error>
5897 <error id="JVMTI_ERROR_TYPE_MISMATCH">
5898 The supplied <paramlink id="value"/> is not compatible
5899 with the variable type.
5900 </error>
5901 <error id="JVMTI_ERROR_OPAQUE_FRAME">
5902 Not a visible frame
5903 </error>
5904 </errors>
5905 </function>
5906
5907 <function id="SetLocalInt" num="27">
5908 <synopsis>Set Local Variable - Int</synopsis>
5909 <description>
5910 This function can be used to set the value of a local
5911 variable whose type is <code>int</code>,
5912 <code>short</code>, <code>char</code>, <code>byte</code>, or
5913 <code>boolean</code>.
5914 </description>
5915 <origin>jvmdi</origin>
5916 <capabilities>
5917 <required id="can_access_local_variables"></required>
5918 </capabilities>
5919 <parameters>
5920 <param id="thread">
5921 <jthread null="current" frame="frame"/>
5922 <description>
5923 The thread of the frame containing the variable's value.
5924 </description>
5925 </param>
5926 <param id="depth">
5927 <jframeID thread="thread"/>
5928 <description>
5929 The depth of the frame containing the variable's value.
5930 </description>
5931 </param>
5932 <param id="slot">
5933 <jint/>
5934 <description>
5935 The variable's slot number.
5936 </description>
5937 </param>
5938 <param id="value">
5939 <jint/>
5940 <description>
5941 The new value for the variable.
5942 </description>
5943 </param>
5944 </parameters>
5945 <errors>
5946 <error id="JVMTI_ERROR_INVALID_SLOT">
5947 Invalid <code>slot</code>.
5948 </error>
5949 <error id="JVMTI_ERROR_TYPE_MISMATCH">
5950 The variable type is not
5951 <code>int</code>, <code>short</code>,
5952 <code>char</code>, <code>byte</code>, or
5953 <code>boolean</code>.
5954 </error>
5955 <error id="JVMTI_ERROR_OPAQUE_FRAME">
5956 Not a visible frame
5957 </error>
5958 </errors>
5959 </function>
5960
5961 <function id="SetLocalLong" num="28">
5962 <synopsis>Set Local Variable - Long</synopsis>
5963 <description>
5964 This function can be used to set the value of a local
5965 variable whose type is <code>long</code>.
5966 </description>
5967 <origin>jvmdi</origin>
5968 <capabilities>
5969 <required id="can_access_local_variables"></required>
5970 </capabilities>
5971 <parameters>
5972 <param id="thread">
5973 <jthread null="current" frame="frame"/>
5974 <description>
5975 The thread of the frame containing the variable's value.
5976 </description>
5977 </param>
5978 <param id="depth">
5979 <jframeID thread="thread"/>
5980 <description>
5981 The depth of the frame containing the variable's value.
5982 </description>
5983 </param>
5984 <param id="slot">
5985 <jint/>
5986 <description>
5987 The variable's slot number.
5988 </description>
5989 </param>
5990 <param id="value">
5991 <jlong/>
5992 <description>
5993 The new value for the variable.
5994 </description>
5995 </param>
5996 </parameters>
5997 <errors>
5998 <error id="JVMTI_ERROR_INVALID_SLOT">
5999 Invalid <code>slot</code>.
6000 </error>
6001 <error id="JVMTI_ERROR_TYPE_MISMATCH">
6002 The variable type is not <code>long</code>.
6003 </error>
6004 <error id="JVMTI_ERROR_OPAQUE_FRAME">
6005 Not a visible frame
6006 </error>
6007 </errors>
6008 </function>
6009
6010 <function id="SetLocalFloat" num="29">
6011 <synopsis>Set Local Variable - Float</synopsis>
6012 <description>
6013 This function can be used to set the value of a local
6014 variable whose type is <code>float</code>.
6015 </description>
6016 <origin>jvmdi</origin>
6017 <capabilities>
6018 <required id="can_access_local_variables"></required>
6019 </capabilities>
6020 <parameters>
6021 <param id="thread">
6022 <jthread null="current" frame="frame"/>
6023 <description>
6024 The thread of the frame containing the variable's value.
6025 </description>
6026 </param>
6027 <param id="depth">
6028 <jframeID thread="thread"/>
6029 <description>
6030 The depth of the frame containing the variable's value.
6031 </description>
6032 </param>
6033 <param id="slot">
6034 <jint/>
6035 <description>
6036 The variable's slot number.
6037 </description>
6038 </param>
6039 <param id="value">
6040 <jfloat/>
6041 <description>
6042 The new value for the variable.
6043 </description>
6044 </param>
6045 </parameters>
6046 <errors>
6047 <error id="JVMTI_ERROR_INVALID_SLOT">
6048 Invalid <code>slot</code>.
6049 </error>
6050 <error id="JVMTI_ERROR_TYPE_MISMATCH">
6051 The variable type is not <code>float</code>.
6052 </error>
6053 <error id="JVMTI_ERROR_OPAQUE_FRAME">
6054 Not a visible frame
6055 </error>
6056 </errors>
6057 </function>
6058
6059 <function id="SetLocalDouble" num="30">
6060 <synopsis>Set Local Variable - Double</synopsis>
6061 <description>
6062 This function can be used to set the value of a local
6063 variable whose type is <code>double</code>.
6064 </description>
6065 <origin>jvmdi</origin>
6066 <capabilities>
6067 <required id="can_access_local_variables"></required>
6068 </capabilities>
6069 <parameters>
6070 <param id="thread">
6071 <jthread null="current" frame="frame"/>
6072 <description>
6073 The thread of the frame containing the variable's value.
6074 </description>
6075 </param>
6076 <param id="depth">
6077 <jframeID thread="thread"/>
6078 <description>
6079 The depth of the frame containing the variable's value.
6080 </description>
6081 </param>
6082 <param id="slot">
6083 <jint/>
6084 <description>
6085 The variable's slot number.
6086 </description>
6087 </param>
6088 <param id="value">
6089 <jdouble/>
6090 <description>
6091 The new value for the variable.
6092 </description>
6093 </param>
6094 </parameters>
6095 <errors>
6096 <error id="JVMTI_ERROR_INVALID_SLOT">
6097 Invalid <code>slot</code>.
6098 </error>
6099 <error id="JVMTI_ERROR_TYPE_MISMATCH">
6100 The variable type is not <code>double</code>.
6101 </error>
6102 <error id="JVMTI_ERROR_OPAQUE_FRAME">
6103 Not a visible frame
6104 </error>
6105 </errors>
6106 </function>
6107 </category>
6108
6109 <category id="breakpointCategory" label="Breakpoint">
6110
6111 <intro>
6112 </intro>
6113
6114 <function id="SetBreakpoint" num="38">
6115 <synopsis>Set Breakpoint</synopsis>
6116 <description>
6117 Set a breakpoint at the instruction indicated by
6118 <code>method</code> and <code>location</code>.
6119 An instruction can only have one breakpoint.
6120 <p/>
6121 Whenever the designated instruction is about to be executed, a
6122 <eventlink id="Breakpoint"></eventlink> event is generated.
6123 </description>
6124 <origin>jvmdi</origin>
6125 <capabilities>
6126 <required id="can_generate_breakpoint_events"></required>
6127 </capabilities>
6128 <parameters>
6129 <param id="klass">
6130 <jclass method="method"/>
6131 <description>
6132 The class in which to set the breakpoint
6133 </description>
6134 </param>
6135 <param id="method">
6136 <jmethodID class="klass"/>
6137 <description>
6138 The method in which to set the breakpoint
6139 </description>
6140 </param>
6141 <param id="location">
6142 <jlocation/>
6143 <description>
6144 the index of the instruction at which to set the breakpoint
6145
6146 </description>
6147 </param>
6148 </parameters>
6149 <errors>
6150 <error id="JVMTI_ERROR_DUPLICATE">
6151 The designated bytecode already has a breakpoint.
6152 </error>
6153 </errors>
6154 </function>
6155
6156 <function id="ClearBreakpoint" num="39">
6157 <synopsis>Clear Breakpoint</synopsis>
6158 <description>
6159 Clear the breakpoint at the bytecode indicated by
6160 <code>method</code> and <code>location</code>.
6161 </description>
6162 <origin>jvmdi</origin>
6163 <capabilities>
6164 <required id="can_generate_breakpoint_events"></required>
6165 </capabilities>
6166 <parameters>
6167 <param id="klass">
6168 <jclass method="method"/>
6169 <description>
6170 The class in which to clear the breakpoint
6171 </description>
6172 </param>
6173 <param id="method">
6174 <jmethodID class="klass"/>
6175 <description>
6176 The method in which to clear the breakpoint
6177 </description>
6178 </param>
6179 <param id="location">
6180 <jlocation/>
6181 <description>
6182 the index of the instruction at which to clear the breakpoint
6183 </description>
6184 </param>
6185 </parameters>
6186 <errors>
6187 <error id="JVMTI_ERROR_NOT_FOUND">
6188 There's no breakpoint at the designated bytecode.
6189 </error>
6190 </errors>
6191 </function>
6192
6193 </category>
6194
6195 <category id="fieldWatch" label="Watched Field">
6196
6197 <intro>
6198 </intro>
6199
6200 <function id="SetFieldAccessWatch" num="41">
6201 <synopsis>Set Field Access Watch</synopsis>
6202 <description>
6203 Generate a <eventlink id="FieldAccess"></eventlink> event
6204 when the field specified
6205 by <code>klass</code> and
6206 <code>field</code> is about to be accessed.
6207 An event will be generated for each access of the field
6208 until it is canceled with
6209 <functionlink id="ClearFieldAccessWatch"></functionlink>.
6210 Field accesses from Java programming language code or from JNI code are watched,
6211 fields modified by other means are not watched.
6212 Note that <jvmti/> users should be aware that their own field accesses
6213 will trigger the watch.
6214 A field can only have one field access watch set.
6215 Modification of a field is not considered an access--use
6216 <functionlink id="SetFieldModificationWatch"></functionlink>
6217 to monitor modifications.
6218 </description>
6219 <origin>jvmdi</origin>
6220 <capabilities>
6221 <required id="can_generate_field_access_events"></required>
6222 </capabilities>
6223 <parameters>
6224 <param id="klass">
6225 <jclass field="field"/>
6226 <description>
6227 The class containing the field to watch
6228 </description>
6229 </param>
6230 <param id="field">
6231 <jfieldID class="klass"/>
6232 <description>
6233 The field to watch
6234
6235 </description>
6236 </param>
6237 </parameters>
6238 <errors>
6239 <error id="JVMTI_ERROR_DUPLICATE">
6240 The designated field is already being watched for accesses.
6241 </error>
6242 </errors>
6243 </function>
6244
6245 <function id="ClearFieldAccessWatch" num="42">
6246 <synopsis>Clear Field Access Watch</synopsis>
6247 <description>
6248 Cancel a field access watch previously set by
6249 <functionlink id="SetFieldAccessWatch"></functionlink>, on the
6250 field specified
6251 by <code>klass</code> and
6252 <code>field</code>.
6253 </description>
6254 <origin>jvmdi</origin>
6255 <capabilities>
6256 <required id="can_generate_field_access_events"></required>
6257 </capabilities>
6258 <parameters>
6259 <param id="klass">
6260 <jclass field="field"/>
6261 <description>
6262 The class containing the field to watch
6263 </description>
6264 </param>
6265 <param id="field">
6266 <jfieldID class="klass"/>
6267 <description>
6268 The field to watch
6269
6270 </description>
6271 </param>
6272 </parameters>
6273 <errors>
6274 <error id="JVMTI_ERROR_NOT_FOUND">
6275 The designated field is not being watched for accesses.
6276 </error>
6277 </errors>
6278 </function>
6279
6280 <function id="SetFieldModificationWatch" num="43">
6281 <synopsis>Set Field Modification Watch</synopsis>
6282 <description>
6283 Generate a <eventlink id="FieldModification"></eventlink> event
6284 when the field specified
6285 by <code>klass</code> and
6286 <code>field</code> is about to be modified.
6287 An event will be generated for each modification of the field
6288 until it is canceled with
6289 <functionlink id="ClearFieldModificationWatch"></functionlink>.
6290 Field modifications from Java programming language code or from JNI code are watched,
6291 fields modified by other means are not watched.
6292 Note that <jvmti/> users should be aware that their own field modifications
6293 will trigger the watch.
6294 A field can only have one field modification watch set.
6295 </description>
6296 <origin>jvmdi</origin>
6297 <capabilities>
6298 <required id="can_generate_field_modification_events"></required>
6299 </capabilities>
6300 <parameters>
6301 <param id="klass">
6302 <jclass field="field"/>
6303 <description>
6304 The class containing the field to watch
6305 </description>
6306 </param>
6307 <param id="field">
6308 <jfieldID class="klass"/>
6309 <description>
6310 The field to watch
6311
6312 </description>
6313 </param>
6314 </parameters>
6315 <errors>
6316 <error id="JVMTI_ERROR_DUPLICATE">
6317 The designated field is already being watched for modifications.
6318 </error>
6319 </errors>
6320 </function>
6321
6322 <function id="ClearFieldModificationWatch" num="44">
6323 <synopsis>Clear Field Modification Watch</synopsis>
6324 <description>
6325
6326 Cancel a field modification watch previously set by
6327 <functionlink id="SetFieldModificationWatch"></functionlink>, on the
6328 field specified
6329 by <code>klass</code> and
6330 <code>field</code>.
6331 </description>
6332 <origin>jvmdi</origin>
6333 <capabilities>
6334 <required id="can_generate_field_modification_events"></required>
6335 </capabilities>
6336 <parameters>
6337 <param id="klass">
6338 <jclass field="field"/>
6339 <description>
6340 The class containing the field to watch
6341 </description>
6342 </param>
6343 <param id="field">
6344 <jfieldID class="klass"/>
6345 <description>
6346 The field to watch
6347
6348 </description>
6349 </param>
6350 </parameters>
6351 <errors>
6352 <error id="JVMTI_ERROR_NOT_FOUND">
6353 The designated field is not being watched for modifications.
6354 </error>
6355 </errors>
6356 </function>
6357 </category>
6358
6359 <category id="class" label="Class">
6360
6361 <intro>
6362 </intro>
6363
6364 <function id="GetLoadedClasses" jkernel="yes" num="78">
6365 <synopsis>Get Loaded Classes</synopsis>
6366 <description>
6367 Return an array of all classes loaded in the virtual machine.
6368 The number of classes in the array is returned via
6369 <code>class_count_ptr</code>, and the array itself via
6370 <code>classes_ptr</code>.
6371 <p/>
6372 Array classes of all types (including arrays of primitive types) are
6373 included in the returned list. Primitive classes (for example,
6374 <code>java.lang.Integer.TYPE</code>) are <i>not</i> included in this list.
6375 </description>
6376 <origin>jvmdi</origin>
6377 <capabilities>
6378 </capabilities>
6379 <parameters>
6380 <param id="class_count_ptr">
6381 <outptr><jint/></outptr>
6382 <description>
6383 On return, points to the number of classes.
6384 </description>
6385 </param>
6386 <param id="classes_ptr">
6387 <allocbuf outcount="class_count_ptr"><jclass/></allocbuf>
6388 <description>
6389 On return, points to an array of references, one
6390 for each class.
6391 </description>
6392 </param>
6393 </parameters>
6394 <errors>
6395 </errors>
6396 </function>
6397
6398 <function id="GetClassLoaderClasses" jkernel="yes" num="79">
6399 <synopsis>Get Classloader Classes</synopsis>
6400 <description>
6401 Returns an array of those classes for which this class loader has
6402 been recorded as an initiating loader. Each
6403 class in the returned array was created by this class loader,
6404 either by defining it directly or by delegation to another class loader.
6405 See the
6406 <vmspeclink id="ConstantPool.doc.html#72007"
6407 name="Creation and Loading section"/>.
6408 <p/>
6409 For JDK version 1.1 implementations that don't
6410 recognize the distinction between initiating and defining class loaders,
6411 this function should return all classes loaded in the virtual machine.
6412 The number of classes in the array is returned via
6413 <code>class_count_ptr</code>, and the array itself via
6414 <code>classes_ptr</code>.
6415 </description>
6416 <origin>jvmdi</origin>
6417 <capabilities>
6418 </capabilities>
6419 <parameters>
6420 <param id="initiating_loader">
6421 <ptrtype>
6422 <jobject/>
6423 <nullok>the classes initiated by the bootstrap loader will be returned</nullok>
6424 </ptrtype>
6425 <description>
6426 An initiating class loader.
6427 </description>
6428 </param>
6429 <param id="class_count_ptr">
6430 <outptr><jint/></outptr>
6431 <description>
6432 On return, points to the number of classes.
6433 </description>
6434 </param>
6435 <param id="classes_ptr">
6436 <allocbuf outcount="class_count_ptr"><jclass/></allocbuf>
6437 <description>
6438 On return, points to an array of references, one
6439 for each class.
6440 </description>
6441 </param>
6442 </parameters>
6443 <errors>
6444 </errors>
6445 </function>
6446
6447 <function id="GetClassSignature" phase="start" num="48">
6448 <synopsis>Get Class Signature</synopsis>
6449 <description>
6450 For the class indicated by <code>klass</code>, return the
6451 <externallink id="http://java.sun.com/javase/6/docs/guide/jni/spec/types.html#wp16432">JNI
6452 type signature</externallink>
6453 and the generic signature of the class.
6454 For example, <code>java.util.List</code> is <code>"Ljava/util/List;"</code>
6455 and <code>int[]</code> is <code>"[I"</code>
6456 The returned name for primitive classes
6457 is the type signature character of the corresponding primitive type.
6458 For example, <code>java.lang.Integer.TYPE</code> is <code>"I"</code>.
6459 </description>
6460 <origin>jvmdiClone</origin>
6461 <capabilities>
6462 </capabilities>
6463 <parameters>
6464 <param id="klass">
6465 <jclass/>
6466 <description>
6467 The class to query.
6468 </description>
6469 </param>
6470 <param id="signature_ptr">
6471 <allocbuf>
6472 <char/>
6473 <nullok>the signature is not returned</nullok>
6474 </allocbuf>
6475 <description>
6476 On return, points to the JNI type signature of the class, encoded as a
6477 <internallink id="mUTF">modified UTF-8</internallink> string.
6478 </description>
6479 </param>
6480 <param id="generic_ptr">
6481 <allocbuf>
6482 <char/>
6483 <nullok>the generic signature is not returned</nullok>
6484 </allocbuf>
6485 <description>
6486 On return, points to the generic signature of the class, encoded as a
6487 <internallink id="mUTF">modified UTF-8</internallink> string.
6488 If there is no generic signature attribute for the class, then,
6489 on return, points to <code>NULL</code>.
6490 </description>
6491 </param>
6492 </parameters>
6493 <errors>
6494 </errors>
6495 </function>
6496
6497 <function id="GetClassStatus" phase="start" num="49">
6498 <synopsis>Get Class Status</synopsis>
6499 <description>
6500 Get the status of the class. Zero or more of the following bits can be
6501 set.
6502 <constants id="jvmtiClassStatus" label="Class Status Flags" kind="bits">
6503 <constant id="JVMTI_CLASS_STATUS_VERIFIED" num="1">
6504 Class bytecodes have been verified
6505 </constant>
6506 <constant id="JVMTI_CLASS_STATUS_PREPARED" num="2">
6507 Class preparation is complete
6508 </constant>
6509 <constant id="JVMTI_CLASS_STATUS_INITIALIZED" num="4">
6510 Class initialization is complete. Static initializer has been run.
6511 </constant>
6512 <constant id="JVMTI_CLASS_STATUS_ERROR" num="8">
6513 Error during initialization makes class unusable
6514 </constant>
6515 <constant id="JVMTI_CLASS_STATUS_ARRAY" num="16">
6516 Class is an array. If set, all other bits are zero.
6517 </constant>
6518 <constant id="JVMTI_CLASS_STATUS_PRIMITIVE" num="32">
6519 Class is a primitive class (for example, <code>java.lang.Integer.TYPE</code>).
6520 If set, all other bits are zero.
6521 </constant>
6522 </constants>
6523 </description>
6524 <origin>jvmdi</origin>
6525 <capabilities>
6526 </capabilities>
6527 <parameters>
6528 <param id="klass">
6529 <jclass/>
6530 <description>
6531 The class to query.
6532 </description>
6533 </param>
6534 <param id="status_ptr">
6535 <outptr><jint/></outptr>
6536 <description>
6537 On return, points to the current state of this class as one or
6538 more of the <internallink id="jvmtiClassStatus">class status flags</internallink>.
6539 </description>
6540 </param>
6541 </parameters>
6542 <errors>
6543 </errors>
6544 </function>
6545
6546 <function id="GetSourceFileName" phase="start" num="50">
6547 <synopsis>Get Source File Name</synopsis>
6548 <description>
6549 For the class indicated by <code>klass</code>, return the source file
6550 name via <code>source_name_ptr</code>. The returned string
6551 is a file name only and never contains a directory name.
6552 <p/>
6553 For primitive classes (for example, <code>java.lang.Integer.TYPE</code>)
6554 and for arrays this function returns
6555 <errorlink id="JVMTI_ERROR_ABSENT_INFORMATION"></errorlink>.
6556 </description>
6557 <origin>jvmdi</origin>
6558 <capabilities>
6559 <required id="can_get_source_file_name"></required>
6560 </capabilities>
6561 <parameters>
6562 <param id="klass">
6563 <jclass/>
6564 <description>
6565 The class to query.
6566 </description>
6567 </param>
6568 <param id="source_name_ptr">
6569 <allocbuf><char/></allocbuf>
6570 <description>
6571 On return, points to the class's source file name, encoded as a
6572 <internallink id="mUTF">modified UTF-8</internallink> string.
6573 </description>
6574 </param>
6575 </parameters>
6576 <errors>
6577 <error id="JVMTI_ERROR_ABSENT_INFORMATION">
6578 Class information does not include a source file name. This includes
6579 cases where the class is an array class or primitive class.
6580 </error>
6581 </errors>
6582 </function>
6583
6584 <function id="GetClassModifiers" phase="start" num="51">
6585 <synopsis>Get Class Modifiers</synopsis>
6586 <description>
6587 For the class indicated by <code>klass</code>, return the access
6588 flags
6589 via <code>modifiers_ptr</code>.
6590 Access flags are defined in the
6591 <vmspeclink id="ClassFile.doc.html"
6592 name="Class File Format chapter"/>.
6593 <p/>
6594 If the class is an array class, then its public, private, and protected
6595 modifiers are the same as those of its component type. For arrays of
6596 primitives, this component type is represented by one of the primitive
6597 classes (for example, <code>java.lang.Integer.TYPE</code>).
6598 <p/>
6599 If the class is a primitive class, its public modifier is always true,
6600 and its protected and private modifiers are always false.
6601 <p/>
6602 If the class is an array class or a primitive class then its final
6603 modifier is always true and its interface modifier is always false.
6604 The values of its other modifiers are not determined by this specification.
6605
6606 </description>
6607 <origin>jvmdi</origin>
6608 <capabilities>
6609 </capabilities>
6610 <parameters>
6611 <param id="klass">
6612 <jclass/>
6613 <description>
6614 The class to query.
6615 </description>
6616 </param>
6617 <param id="modifiers_ptr">
6618 <outptr><jint/></outptr>
6619 <description>
6620 On return, points to the current access flags of this class.
6621
6622 </description>
6623 </param>
6624 </parameters>
6625 <errors>
6626 </errors>
6627 </function>
6628
6629 <function id="GetClassMethods" phase="start" num="52">
6630 <synopsis>Get Class Methods</synopsis>
6631 <description>
6632 For the class indicated by <code>klass</code>, return a count of
6633 methods via <code>method_count_ptr</code> and a list of
6634 method IDs via <code>methods_ptr</code>. The method list contains
6635 constructors and static initializers as well as true methods.
6636 Only directly declared methods are returned (not inherited methods).
6637 An empty method list is returned for array classes and primitive classes
6638 (for example, <code>java.lang.Integer.TYPE</code>).
6639 </description>
6640 <origin>jvmdi</origin>
6641 <capabilities>
6642 <capability id="can_maintain_original_method_order"/>
6643 </capabilities>
6644 <parameters>
6645 <param id="klass">
6646 <jclass/>
6647 <description>
6648 The class to query.
6649 </description>
6650 </param>
6651 <param id="method_count_ptr">
6652 <outptr><jint/></outptr>
6653 <description>
6654 On return, points to the number of methods declared in this class.
6655 </description>
6656 </param>
6657 <param id="methods_ptr">
6658 <allocbuf outcount="method_count_ptr"><jmethodID class="klass"/></allocbuf>
6659 <description>
6660 On return, points to the method ID array.
6661 </description>
6662 </param>
6663 </parameters>
6664 <errors>
6665 <error id="JVMTI_ERROR_CLASS_NOT_PREPARED">
6666 <paramlink id="klass"></paramlink> is not prepared.
6667 </error>
6668 </errors>
6669 </function>
6670
6671 <function id="GetClassFields" phase="start" num="53">
6672 <synopsis>Get Class Fields</synopsis>
6673 <description>
6674 For the class indicated by <code>klass</code>, return a count of fields
6675 via <code>field_count_ptr</code> and a list of field IDs via
6676 <code>fields_ptr</code>.
6677 Only directly declared fields are returned (not inherited fields).
6678 Fields are returned in the order they occur in the class file.
6679 An empty field list is returned for array classes and primitive classes
6680 (for example, <code>java.lang.Integer.TYPE</code>).
6681 Use JNI to determine the length of an array.
6682 </description>
6683 <origin>jvmdi</origin>
6684 <capabilities>
6685 </capabilities>
6686 <parameters>
6687 <param id="klass">
6688 <jclass/>
6689 <description>
6690 The class to query.
6691 </description>
6692 </param>
6693 <param id="field_count_ptr">
6694 <outptr><jint/></outptr>
6695 <description>
6696 On return, points to the number of fields declared in this class.
6697 </description>
6698 </param>
6699 <param id="fields_ptr">
6700 <allocbuf outcount="field_count_ptr"><jfieldID/></allocbuf>
6701 <description>
6702 On return, points to the field ID array.
6703 </description>
6704 </param>
6705 </parameters>
6706 <errors>
6707 <error id="JVMTI_ERROR_CLASS_NOT_PREPARED">
6708 <paramlink id="klass"></paramlink> is not prepared.
6709 </error>
6710 </errors>
6711 </function>
6712
6713 <function id="GetImplementedInterfaces" phase="start" num="54">
6714 <synopsis>Get Implemented Interfaces</synopsis>
6715 <description>
6716 Return the direct super-interfaces of this class. For a class, this
6717 function returns the interfaces declared in its <code>implements</code>
6718 clause. For an interface, this function returns the interfaces declared in
6719 its <code>extends</code> clause.
6720 An empty interface list is returned for array classes and primitive classes
6721 (for example, <code>java.lang.Integer.TYPE</code>).
6722 </description>
6723 <origin>jvmdi</origin>
6724 <capabilities>
6725 </capabilities>
6726 <parameters>
6727 <param id="klass">
6728 <jclass/>
6729 <description>
6730 The class to query.
6731 </description>
6732 </param>
6733 <param id="interface_count_ptr">
6734 <outptr><jint/></outptr>
6735 <description>
6736 On return, points to the number of interfaces.
6737 </description>
6738 </param>
6739 <param id="interfaces_ptr">
6740 <allocbuf outcount="interface_count_ptr"><jclass/></allocbuf>
6741 <description>
6742 On return, points to the interface array.
6743 </description>
6744 </param>
6745 </parameters>
6746 <errors>
6747 <error id="JVMTI_ERROR_CLASS_NOT_PREPARED">
6748 <paramlink id="klass"></paramlink> is not prepared.
6749 </error>
6750 </errors>
6751 </function>
6752
6753 <function id="GetClassVersionNumbers" phase="start" num="145" since="1.1">
6754 <synopsis>Get Class Version Numbers</synopsis>
6755 <description>
6756 For the class indicated by <code>klass</code>,
6757 return the minor and major version numbers,
6758 as defined in the
6759 <vmspeclink id="ClassFile.doc.html"
6760 name="Class File Format chapter"/>.
6761 </description>
6762 <origin>new</origin>
6763 <capabilities>
6764 </capabilities>
6765 <parameters>
6766 <param id="klass">
6767 <jclass/>
6768 <description>
6769 The class to query.
6770 </description>
6771 </param>
6772 <param id="minor_version_ptr">
6773 <outptr><jint/></outptr>
6774 <description>
6775 On return, points to the value of the
6776 <code>minor_version</code> item of the
6777 Class File Format.
6778 Note: to be consistent with the Class File Format,
6779 the minor version number is the first parameter.
6780 </description>
6781 </param>
6782 <param id="major_version_ptr">
6783 <outptr><jint/></outptr>
6784 <description>
6785 On return, points to the value of the
6786 <code>major_version</code> item of the
6787 Class File Format.
6788 </description>
6789 </param>
6790 </parameters>
6791 <errors>
6792 <error id="JVMTI_ERROR_ABSENT_INFORMATION">
6793 The class is a primitive or array class.
6794 </error>
6795 </errors>
6796 </function>
6797
6798 <function id="GetConstantPool" phase="start" num="146" since="1.1">
6799 <synopsis>Get Constant Pool</synopsis>
6800 <description>
6801 For the class indicated by <code>klass</code>,
6802 return the raw bytes of the constant pool in the format of the
6803 <code>constant_pool</code> item of the
6804 <vmspeclink id="ClassFile.doc.html"
6805 name="Class File Format"
6806 preposition="in"/>.
6807 The format of the constant pool may differ between versions
6808 of the Class File Format, so, the
6809 <functionlink id="GetClassVersionNumbers">minor and major
6810 class version numbers</functionlink> should be checked for
6811 compatibility.
6812 <p/>
6813 The returned constant pool might not have the same layout or
6814 contents as the constant pool in the defining class file.
6815 The constant pool returned by GetConstantPool() may have
6816 more or fewer entries than the defining constant pool.
6817 Entries may be in a different order.
6818 The constant pool returned by GetConstantPool() will match the
6819 constant pool used by
6820 <functionlink id="GetBytecodes">GetBytecodes()</functionlink>.
6821 That is, the bytecodes returned by GetBytecodes() will have
6822 constant pool indices which refer to constant pool entries returned
6823 by GetConstantPool().
6824 Note that since <functionlink id="RetransformClasses"/>
6825 and <functionlink id="RedefineClasses"/> can change
6826 the constant pool, the constant pool returned by this function
6827 can change accordingly. Thus, the correspondence between
6828 GetConstantPool() and GetBytecodes() does not hold if there
6829 is an intervening class retransformation or redefinition.
6830 The value of a constant pool entry used by a given bytecode will
6831 match that of the defining class file (even if the indices don't match).
6832 Constant pool entries which are not used directly or indirectly by
6833 bytecodes (for example, UTF-8 strings associated with annotations) are
6834 not required to exist in the returned constant pool.
6835 </description>
6836 <origin>new</origin>
6837 <capabilities>
6838 <required id="can_get_constant_pool"></required>
6839 </capabilities>
6840 <parameters>
6841 <param id="klass">
6842 <jclass/>
6843 <description>
6844 The class to query.
6845 </description>
6846 </param>
6847 <param id="constant_pool_count_ptr">
6848 <outptr><jint/></outptr>
6849 <description>
6850 On return, points to the number of entries
6851 in the constant pool table plus one.
6852 This corresponds to the <code>constant_pool_count</code>
6853 item of the Class File Format.
6854 </description>
6855 </param>
6856 <param id="constant_pool_byte_count_ptr">
6857 <outptr><jint/></outptr>
6858 <description>
6859 On return, points to the number of bytes
6860 in the returned raw constant pool.
6861 </description>
6862 </param>
6863 <param id="constant_pool_bytes_ptr">
6864 <allocbuf outcount="constant_pool_byte_count_ptr"><uchar/></allocbuf>
6865 <description>
6866 On return, points to the raw constant pool, that is the bytes
6867 defined by the <code>constant_pool</code> item of the
6868 Class File Format
6869 </description>
6870 </param>
6871 </parameters>
6872 <errors>
6873 <error id="JVMTI_ERROR_ABSENT_INFORMATION">
6874 The class is a primitive or array class.
6875 </error>
6876 </errors>
6877 </function>
6878
6879 <function id="IsInterface" phase="start" num="55">
6880 <synopsis>Is Interface</synopsis>
6881 <description>
6882 Determines whether a class object reference represents an interface.
6883 The <code>jboolean</code> result is
6884 <code>JNI_TRUE</code> if the "class" is actually an interface,
6885 <code>JNI_FALSE</code> otherwise.
6886 </description>
6887 <origin>jvmdi</origin>
6888 <capabilities>
6889 </capabilities>
6890 <parameters>
6891 <param id="klass">
6892 <jclass/>
6893 <description>
6894 The class to query.
6895 </description>
6896 </param>
6897 <param id="is_interface_ptr">
6898 <outptr><jboolean/></outptr>
6899 <description>
6900 On return, points to the boolean result of this function.
6901
6902 </description>
6903 </param>
6904 </parameters>
6905 <errors>
6906 </errors>
6907 </function>
6908
6909 <function id="IsArrayClass" phase="start" num="56">
6910 <synopsis>Is Array Class</synopsis>
6911 <description>
6912 Determines whether a class object reference represents an array.
6913 The <code>jboolean</code> result is
6914 <code>JNI_TRUE</code> if the class is an array,
6915 <code>JNI_FALSE</code> otherwise.
6916 </description>
6917 <origin>jvmdi</origin>
6918 <capabilities>
6919 </capabilities>
6920 <parameters>
6921 <param id="klass">
6922 <jclass/>
6923 <description>
6924 The class to query.
6925 </description>
6926 </param>
6927 <param id="is_array_class_ptr">
6928 <outptr><jboolean/></outptr>
6929 <description>
6930 On return, points to the boolean result of this function.
6931
6932 </description>
6933 </param>
6934 </parameters>
6935 <errors>
6936 </errors>
6937 </function>
6938
6939 <function id="IsModifiableClass" jkernel="yes" phase="start" num="45" since="1.1">
6940 <synopsis>Is Modifiable Class</synopsis>
6941 <description>
6942 Determines whether a class is modifiable.
6943 If a class is modifiable (<paramlink id="is_modifiable_class_ptr"/>
6944 returns <code>JNI_TRUE</code>) the class can be
6945 redefined with <functionlink id="RedefineClasses"/> (assuming
6946 the agent possesses the
6947 <fieldlink id="can_redefine_classes" struct="jvmtiCapabilities"/>
6948 capability) or
6949 retransformed with <functionlink id="RetransformClasses"/> (assuming
6950 the agent possesses the
6951 <fieldlink id="can_retransform_classes" struct="jvmtiCapabilities"/>
6952 capability).
6953 If a class is not modifiable (<paramlink id="is_modifiable_class_ptr"/>
6954 returns <code>JNI_FALSE</code>) the class can be neither
6955 redefined nor retransformed.
6956 <p/>
6957 Primitive classes (for example, <code>java.lang.Integer.TYPE</code>)
6958 and array classes are never modifiable.
6959 <p/>
6960 </description>
6961 <origin>new</origin>
6962 <capabilities>
6963 <capability id="can_redefine_any_class">
6964 If possessed then all classes (except primitive and array classes)
6965 are modifiable.
6966 </capability>
6967 <capability id="can_redefine_classes">
6968 No effect on the result of the function.
6969 But must additionally be possessed to modify the class with
6970 <functionlink id="RedefineClasses"/>.
6971 </capability>
6972 <capability id="can_retransform_classes">
6973 No effect on the result of the function.
6974 But must additionally be possessed to modify the class with
6975 <functionlink id="RetransformClasses"/>.
6976 </capability>
6977 </capabilities>
6978 <parameters>
6979 <param id="klass">
6980 <jclass/>
6981 <description>
6982 The class to query.
6983 </description>
6984 </param>
6985 <param id="is_modifiable_class_ptr">
6986 <outptr><jboolean/></outptr>
6987 <description>
6988 On return, points to the boolean result of this function.
6989 </description>
6990 </param>
6991 </parameters>
6992 <errors>
6993 </errors>
6994 </function>
6995
6996 <function id="GetClassLoader" phase="start" num="57">
6997 <synopsis>Get Class Loader</synopsis>
6998 <description>
6999 For the class indicated by <code>klass</code>, return via
7000 <code>classloader_ptr</code> a reference to the class loader for the
7001 class.
7002 </description>
7003 <origin>jvmdi</origin>
7004 <capabilities>
7005 </capabilities>
7006 <parameters>
7007 <param id="klass">
7008 <jclass/>
7009 <description>
7010 The class to query.
7011 </description>
7012 </param>
7013 <param id="classloader_ptr">
7014 <outptr><jobject/></outptr>
7015 <description>
7016 On return, points to the class loader that loaded
7017 this class.
7018 If the class was not created by a class loader
7019 or if the class loader is the bootstrap class loader,
7020 points to <code>NULL</code>.
7021 </description>
7022 </param>
7023 </parameters>
7024 <errors>
7025 </errors>
7026
7027 </function>
7028
7029 <function id="GetSourceDebugExtension" phase="start" num="90">
7030 <synopsis>Get Source Debug Extension</synopsis>
7031 <description>
7032 For the class indicated by <code>klass</code>, return the debug
7033 extension via <code>source_debug_extension_ptr</code>.
7034 The returned string
7035 contains exactly the debug extension information present in the
7036 class file of <code>klass</code>.
7037 </description>
7038 <origin>jvmdi</origin>
7039 <capabilities>
7040 <required id="can_get_source_debug_extension"></required>
7041 </capabilities>
7042 <parameters>
7043 <param id="klass">
7044 <jclass/>
7045 <description>
7046 The class to query.
7047 </description>
7048 </param>
7049 <param id="source_debug_extension_ptr">
7050 <allocbuf><char/></allocbuf>
7051 <description>
7052 On return, points to the class's debug extension, encoded as a
7053 <internallink id="mUTF">modified UTF-8</internallink> string.
7054 </description>
7055 </param>
7056 </parameters>
7057 <errors>
7058 <error id="JVMTI_ERROR_ABSENT_INFORMATION">
7059 Class information does not include a debug extension.
7060 </error>
7061 </errors>
7062 </function>
7063
7064 <function id="RetransformClasses" jkernel="yes" num="152" since="1.1">
7065 <synopsis>Retransform Classes</synopsis>
7066 <description>
7067 This function facilitates the
7068 <internallink id="bci">bytecode instrumentation</internallink>
7069 of already loaded classes.
7070 To replace the class definition without reference to the existing
7071 bytecodes, as one might do when recompiling from source for
7072 fix-and-continue debugging, <functionlink id="RedefineClasses"/>
7073 function should be used instead.
7074 <p/>
7075 When classes are initially loaded or when they are
7076 <functionlink id="RedefineClasses">redefined</functionlink>,
7077 the initial class file bytes can be transformed with the
7078 <eventlink id="ClassFileLoadHook"/> event.
7079 This function reruns the transformation process
7080 (whether or not a transformation has previously occurred).
7081 This retransformation follows these steps:
7082 <ul>
7083 <li>starting from the initial class file bytes
7084 </li>
7085 <li>for each <fieldlink id="can_retransform_classes"
7086 struct="jvmtiCapabilities">retransformation
7087 incapable</fieldlink>
7088 agent which received a
7089 <code>ClassFileLoadHook</code> event during the previous
7090 load or redefine, the bytes it returned
7091 (via the <code>new_class_data</code> parameter)
7092 are reused as the output of the transformation;
7093 note that this is equivalent to reapplying
7094 the previous transformation, unaltered. except that
7095 the <code>ClassFileLoadHook</code> event
7096 is <b>not</b> sent to these agents
7097 </li>
7098 <li>for each <fieldlink id="can_retransform_classes"
7099 struct="jvmtiCapabilities">retransformation
7100 capable</fieldlink>
7101 agent, the <code>ClassFileLoadHook</code> event is sent,
7102 allowing a new transformation to be applied
7103 </li>
7104 <li>the transformed class file bytes are installed as the new
7105 definition of the class
7106 </li>
7107 </ul>
7108 See the <eventlink id="ClassFileLoadHook"/> event for more details.
7109 <p/>
7110 The initial class file bytes represent the bytes passed to
7111 <code>ClassLoader.defineClass</code>
7112 or <code>RedefineClasses</code> (before any transformations
7113 were applied), however they may not exactly match them.
7114 The constant pool may differ in ways described in
7115 <functionlink id="GetConstantPool"/>.
7116 Constant pool indices in the bytecodes of methods will correspond.
7117 Some attributes may not be present.
7118 Where order is not meaningful, for example the order of methods,
7119 order may not be preserved.
7120 <p/>
7121 Retransformation can cause new versions of methods to be installed.
7122 Old method versions may become
7123 <internallink id="obsoleteMethods">obsolete</internallink>
7124 The new method version will be used on new invokes.
7125 If a method has active stack frames, those active frames continue to
7126 run the bytecodes of the original method version.
7127 <p/>
7128 This function does not cause any initialization except that which
7129 would occur under the customary JVM semantics.
7130 In other words, retransforming a class does not cause its initializers to be
7131 run. The values of static fields will remain as they were
7132 prior to the call.
7133 <p/>
7134 Threads need not be suspended.
7135 <p/>
7136 All breakpoints in the class are cleared.
7137 <p/>
7138 All attributes are updated.
7139 <p/>
7140 Instances of the retransformed class are not affected -- fields retain their
7141 previous values.
7142 <functionlink id="GetTag">Tags</functionlink> on the instances are
7143 also unaffected.
7144 <p/>
7145 In response to this call, no events other than the
7146 <eventlink id="ClassFileLoadHook"/> event
7147 will be sent.
7148 <p/>
7149 The retransformation may change method bodies, the constant pool and attributes.
7150 The retransformation must not add, remove or rename fields or methods, change the
7151 signatures of methods, change modifiers, or change inheritance.
7152 These restrictions may be lifted in future versions.
7153 See the error return description below for information on error codes
7154 returned if an unsupported retransformation is attempted.
7155 The class file bytes are not verified or installed until they have passed
7156 through the chain of <eventlink id="ClassFileLoadHook"/> events, thus the
7157 returned error code reflects the result of the transformations.
7158 If any error code is returned other than <code>JVMTI_ERROR_NONE</code>,
7159 none of the classes to be retransformed will have a new definition installed.
7160 When this function returns (with the error code of <code>JVMTI_ERROR_NONE</code>)
7161 all of the classes to be retransformed will have their new definitions installed.
7162 </description>
7163 <origin>new</origin>
7164 <capabilities>
7165 <required id="can_retransform_classes"></required>
7166 <capability id="can_retransform_any_class"></capability>
7167 </capabilities>
7168 <parameters>
7169 <param id="class_count">
7170 <jint min="0"/>
7171 <description>
7172 The number of classes to be retransformed.
7173 </description>
7174 </param>
7175 <param id="classes">
7176 <inbuf incount="class_count"><jclass/></inbuf>
7177 <description>
7178 The array of classes to be retransformed.
7179 </description>
7180 </param>
7181 </parameters>
7182 <errors>
7183 <error id="JVMTI_ERROR_UNMODIFIABLE_CLASS">
7184 One of the <paramlink id="classes"/> cannot be modified.
7185 See <functionlink id="IsModifiableClass"/>.
7186 </error>
7187 <error id="JVMTI_ERROR_INVALID_CLASS">
7188 One of the <paramlink id="classes"/> is not a valid class.
7189 </error>
7190 <error id="JVMTI_ERROR_UNSUPPORTED_VERSION">
7191 A retransformed class file has a version number not supported by this VM.
7192 </error>
7193 <error id="JVMTI_ERROR_INVALID_CLASS_FORMAT">
7194 A retransformed class file is malformed (The VM would return a <code>ClassFormatError</code>).
7195 </error>
7196 <error id="JVMTI_ERROR_CIRCULAR_CLASS_DEFINITION">
7197 The retransformed class file definitions would lead to a circular definition
7198 (the VM would return a <code>ClassCircularityError</code>).
7199 </error>
7200 <error id="JVMTI_ERROR_FAILS_VERIFICATION">
7201 The retransformed class file bytes fail verification.
7202 </error>
7203 <error id="JVMTI_ERROR_NAMES_DONT_MATCH">
7204 The class name defined in a retransformed class file is
7205 different from the name in the old class object.
7206 </error>
7207 <error id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_ADDED">
7208 A retransformed class file would require adding a method.
7209 </error>
7210 <error id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_SCHEMA_CHANGED">
7211 A retransformed class file changes a field.
7212 </error>
7213 <error id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_HIERARCHY_CHANGED">
7214 A direct superclass is different for a retransformed class file,
7215 or the set of directly implemented
7216 interfaces is different.
7217 </error>
7218 <error id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_DELETED">
7219 A retransformed class file does not declare a method
7220 declared in the old class version.
7221 </error>
7222 <error id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_CLASS_MODIFIERS_CHANGED">
7223 A retransformed class file has different class modifiers.
7224 </error>
7225 <error id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_MODIFIERS_CHANGED">
7226 A method in the retransformed class file has different modifiers
7227 than its counterpart in the old class version.
7228 </error>
7229 </errors>
7230 </function>
7231
7232 <function id="RedefineClasses" jkernel="yes" num="87">
7233 <synopsis>Redefine Classes</synopsis>
7234 <typedef id="jvmtiClassDefinition" label="Class redefinition description">
7235 <field id="klass">
7236 <jclass/>
7237 <description>
7238 Class object for this class
7239 </description>
7240 </field>
7241 <field id="class_byte_count">
7242 <jint/>
7243 <description>
7244 Number of bytes defining class (below)
7245 </description>
7246 </field>
7247 <field id="class_bytes">
7248 <inbuf incount="class_byte_count"><uchar/></inbuf>
7249 <description>
7250 Bytes defining class (in the
7251 <vmspeclink id="ClassFile.doc.html"
7252 name="Class File Format"/>)
7253 </description>
7254 </field>
7255 </typedef>
7256 <description>
7257 All classes given are redefined according to the definitions
7258 supplied.
7259 This function is used to replace the definition of a class
7260 with a new definition, as might be needed in fix-and-continue
7261 debugging.
7262 Where the existing class file bytes are to be transformed, for
7263 example in
7264 <internallink id="bci">bytecode instrumentation</internallink>,
7265 <functionlink id="RetransformClasses"/> should be used.
7266 <p/>
7267 Redefinition can cause new versions of methods to be installed.
7268 Old method versions may become
7269 <internallink id="obsoleteMethods">obsolete</internallink>
7270 The new method version will be used on new invokes.
7271 If a method has active stack frames, those active frames continue to
7272 run the bytecodes of the original method version.
7273 If resetting of stack frames is desired, use
7274 <functionlink id="PopFrame"></functionlink>
7275 to pop frames with obsolete method versions.
7276 <p/>
7277 This function does not cause any initialization except that which
7278 would occur under the customary JVM semantics.
7279 In other words, redefining a class does not cause its initializers to be
7280 run. The values of static fields will remain as they were
7281 prior to the call.
7282 <p/>
7283 Threads need not be suspended.
7284 <p/>
7285 All breakpoints in the class are cleared.
7286 <p/>
7287 All attributes are updated.
7288 <p/>
7289 Instances of the redefined class are not affected -- fields retain their
7290 previous values.
7291 <functionlink id="GetTag">Tags</functionlink> on the instances are
7292 also unaffected.
7293 <p/>
7294 In response to this call, the <jvmti/> event
7295 <eventlink id="ClassFileLoadHook">Class File Load Hook</eventlink>
7296 will be sent (if enabled), but no other <jvmti/> events will be sent.
7297 <p/>
7298 The redefinition may change method bodies, the constant pool and attributes.
7299 The redefinition must not add, remove or rename fields or methods, change the
7300 signatures of methods, change modifiers, or change inheritance.
7301 These restrictions may be lifted in future versions.
7302 See the error return description below for information on error codes
7303 returned if an unsupported redefinition is attempted.
7304 The class file bytes are not verified or installed until they have passed
7305 through the chain of <eventlink id="ClassFileLoadHook"/> events, thus the
7306 returned error code reflects the result of the transformations applied
7307 to the bytes passed into <paramlink id="class_definitions"/>.
7308 If any error code is returned other than <code>JVMTI_ERROR_NONE</code>,
7309 none of the classes to be redefined will have a new definition installed.
7310 When this function returns (with the error code of <code>JVMTI_ERROR_NONE</code>)
7311 all of the classes to be redefined will have their new definitions installed.
7312 </description>
7313 <origin>jvmdi</origin>
7314 <capabilities>
7315 <required id="can_redefine_classes"></required>
7316 <capability id="can_redefine_any_class"></capability>
7317 </capabilities>
7318 <parameters>
7319 <param id="class_count">
7320 <jint min="0"/>
7321 <description>
7322 The number of classes specified in <code>class_definitions</code>
7323 </description>
7324 </param>
7325 <param id="class_definitions">
7326 <inbuf incount="class_count"><struct>jvmtiClassDefinition</struct></inbuf>
7327 <description>
7328 The array of new class definitions
7329 </description>
7330 </param>
7331 </parameters>
7332 <errors>
7333 <error id="JVMTI_ERROR_NULL_POINTER">
7334 One of <code>class_bytes</code> is <code>NULL</code>.
7335 </error>
7336 <error id="JVMTI_ERROR_UNMODIFIABLE_CLASS">
7337 An element of <code>class_definitions</code> cannot be modified.
7338 See <functionlink id="IsModifiableClass"/>.
7339 </error>
7340 <error id="JVMTI_ERROR_INVALID_CLASS">
7341 An element of <code>class_definitions</code> is not a valid class.
7342 </error>
7343 <error id="JVMTI_ERROR_UNSUPPORTED_VERSION">
7344 A new class file has a version number not supported by this VM.
7345 </error>
7346 <error id="JVMTI_ERROR_INVALID_CLASS_FORMAT">
7347 A new class file is malformed (The VM would return a <code>ClassFormatError</code>).
7348 </error>
7349 <error id="JVMTI_ERROR_CIRCULAR_CLASS_DEFINITION">
7350 The new class file definitions would lead to a circular definition
7351 (the VM would return a <code>ClassCircularityError</code>).
7352 </error>
7353 <error id="JVMTI_ERROR_FAILS_VERIFICATION">
7354 The class bytes fail verification.
7355 </error>
7356 <error id="JVMTI_ERROR_NAMES_DONT_MATCH">
7357 The class name defined in a new class file is
7358 different from the name in the old class object.
7359 </error>
7360 <error id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_ADDED">
7361 A new class file would require adding a method.
7362 </error>
7363 <error id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_SCHEMA_CHANGED">
7364 A new class version changes a field.
7365 </error>
7366 <error id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_HIERARCHY_CHANGED">
7367 A direct superclass is different for a new class
7368 version, or the set of directly implemented
7369 interfaces is different.
7370 </error>
7371 <error id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_DELETED">
7372 A new class version does not declare a method
7373 declared in the old class version.
7374 </error>
7375 <error id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_CLASS_MODIFIERS_CHANGED">
7376 A new class version has different modifiers.
7377 </error>
7378 <error id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_MODIFIERS_CHANGED">
7379 A method in the new class version has different modifiers
7380 than its counterpart in the old class version.
7381 </error>
7382 </errors>
7383 </function>
7384
7385 </category>
7386
7387 <category id="object" label="Object">
7388
7389 <function id="GetObjectSize" jkernel="yes" phase="start" num="154">
7390 <synopsis>Get Object Size</synopsis>
7391 <description>
7392 For the object indicated by <code>object</code>,
7393 return via <code>size_ptr</code> the size of the object.
7394 This size is an implementation-specific approximation of
7395 the amount of storage consumed by this object.
7396 It may include some or all of the object's overhead, and thus
7397 is useful for comparison within an implementation but not
7398 between implementations.
7399 The estimate may change during a single invocation of the JVM.
7400 </description>
7401 <origin>new</origin>
7402 <capabilities>
7403 </capabilities>
7404 <parameters>
7405 <param id="object">
7406 <jobject/>
7407 <description>
7408 The object to query.
7409 </description>
7410 </param>
7411 <param id="size_ptr">
7412 <outptr><jlong/></outptr>
7413 <description>
7414 On return, points to the object's size in bytes.
7415 </description>
7416 </param>
7417 </parameters>
7418 <errors>
7419 </errors>
7420 </function>
7421
7422 <function id="GetObjectHashCode" phase="start" num="58">
7423 <synopsis>Get Object Hash Code</synopsis>
7424 <description>
7425 For the object indicated by <code>object</code>,
7426 return via <code>hash_code_ptr</code> a hash code.
7427 This hash code could be used to maintain a hash table of object references,
7428 however, on some implementations this can cause significant performance
7429 impacts--in most cases
7430 <internallink id="Heap">tags</internallink>
7431 will be a more efficient means of associating information with objects.
7432 This function guarantees
7433 the same hash code value for a particular object throughout its life
7434 </description>
7435 <origin>jvmdi</origin>
7436 <capabilities>
7437 </capabilities>
7438 <parameters>
7439 <param id="object">
7440 <jobject/>
7441 <description>
7442 The object to query.
7443 </description>
7444 </param>
7445 <param id="hash_code_ptr">
7446 <outptr><jint/></outptr>
7447 <description>
7448 On return, points to the object's hash code.
7449 </description>
7450 </param>
7451 </parameters>
7452 <errors>
7453 </errors>
7454 </function>
7455
7456 <function id="GetObjectMonitorUsage" num="59">
7457 <synopsis>Get Object Monitor Usage</synopsis>
7458 <typedef id="jvmtiMonitorUsage" label="Object monitor usage information">
7459 <field id="owner">
7460 <jthread/>
7461 <description>
7462 The thread owning this monitor, or <code>NULL</code> if unused
7463 </description>
7464 </field>
7465 <field id="entry_count">
7466 <jint/>
7467 <description>
7468 The number of times the owning thread has entered the monitor
7469 </description>
7470 </field>
7471 <field id="waiter_count">
7472 <jint/>
7473 <description>
7474 The number of threads waiting to own this monitor
7475 </description>
7476 </field>
7477 <field id="waiters">
7478 <allocfieldbuf><jthread/></allocfieldbuf>
7479 <description>
7480 The <code>waiter_count</code> waiting threads
7481 </description>
7482 </field>
7483 <field id="notify_waiter_count">
7484 <jint/>
7485 <description>
7486 The number of threads waiting to be notified by this monitor
7487 </description>
7488 </field>
7489 <field id="notify_waiters">
7490 <allocfieldbuf><jthread/></allocfieldbuf>
7491 <description>
7492 The <code>notify_waiter_count</code> threads waiting to be notified
7493 </description>
7494 </field>
7495 </typedef>
7496 <description>
7497 Get information about the object's monitor.
7498 The fields of the <functionlink id="jvmtiMonitorUsage"></functionlink> structure
7499 are filled in with information about usage of the monitor.
7500 <todo>
7501 Decide and then clarify suspend requirements.
7502 </todo>
7503 </description>
7504 <origin>jvmdi</origin>
7505 <capabilities>
7506 <required id="can_get_monitor_info"></required>
7507 </capabilities>
7508 <parameters>
7509 <param id="object">
7510 <jobject/>
7511 <description>
7512 The object to query.
7513 </description>
7514 </param>
7515 <param id="info_ptr">
7516 <outptr><struct>jvmtiMonitorUsage</struct></outptr>
7517 <description>
7518 On return, filled with monitor information for the
7519 specified object.
7520 </description>
7521 </param>
7522 </parameters>
7523 <errors>
7524 </errors>
7525 </function>
7526
7527 <elide>
7528 <function id="GetObjectMonitors" num="116">
7529 <synopsis>Get Object Monitors</synopsis>
7530 <description>
7531 Return the list of object monitors.
7532 <p/>
7533 Note: details about each monitor can be examined with
7534 <functionlink id="GetObjectMonitorUsage"></functionlink>.
7535 </description>
7536 <origin>new</origin>
7537 <capabilities>
7538 <required id="can_get_monitor_info"></required>
7539 </capabilities>
7540 <parameters>
7541 <param id="monitorCnt">
7542 <outptr><jint/></outptr>
7543 <description>
7544 On return, pointer to the number
7545 of monitors returned in <code>monitors_ptr</code>.
7546 </description>
7547 </param>
7548 <param id="monitors_ptr">
7549 <allocbuf outcount="monitorCnt"><jobject/></allocbuf>
7550 <description>
7551 On return, pointer to the monitor list.
7552 </description>
7553 </param>
7554 </parameters>
7555 <errors>
7556 </errors>
7557 </function>
7558 </elide>
7559
7560 </category>
7561
7562 <category id="fieldCategory" label="Field">
7563
7564 <intro>
7565 </intro>
7566
7567 <function id="GetFieldName" phase="start" num="60">
7568 <synopsis>Get Field Name (and Signature)</synopsis>
7569 <description>
7570 For the field indicated by <paramlink id="klass"/> and <paramlink id="field"/>,
7571 return the field name via <paramlink id="name_ptr"/> and field signature via
7572 <paramlink id="signature_ptr"/>.
7573 <p/>
7574 Field signatures are defined in the JNI Specification and
7575 are referred to as
7576 <vmspeclink id="ClassFile.doc.html#14152"
7577 name="field descriptors"
7578 preposition="in"/>.
7579 </description>
7580 <origin>jvmdiClone</origin>
7581 <capabilities>
7582 </capabilities>
7583 <parameters>
7584 <param id="klass">
7585 <jclass field="field"/>
7586 <description>
7587 The class of the field to query.
7588 </description>
7589 </param>
7590 <param id="field">
7591 <jfieldID class="klass"/>
7592 <description>
7593 The field to query.
7594 </description>
7595 </param>
7596 <param id="name_ptr">
7597 <allocbuf>
7598 <char/>
7599 <nullok>the name is not returned</nullok>
7600 </allocbuf>
7601 <description>
7602 On return, points to the field name, encoded as a
7603 <internallink id="mUTF">modified UTF-8</internallink> string.
7604 </description>
7605 </param>
7606 <param id="signature_ptr">
7607 <allocbuf>
7608 <char/>
7609 <nullok>the signature is not returned</nullok>
7610 </allocbuf>
7611 <description>
7612 On return, points to the field signature, encoded as a
7613 <internallink id="mUTF">modified UTF-8</internallink> string.
7614 </description>
7615 </param>
7616 <param id="generic_ptr">
7617 <allocbuf>
7618 <char/>
7619 <nullok>the generic signature is not returned</nullok>
7620 </allocbuf>
7621 <description>
7622 On return, points to the generic signature of the field, encoded as a
7623 <internallink id="mUTF">modified UTF-8</internallink> string.
7624 If there is no generic signature attribute for the field, then,
7625 on return, points to <code>NULL</code>.
7626 </description>
7627 </param>
7628 </parameters>
7629 <errors>
7630 </errors>
7631 </function>
7632
7633 <function id="GetFieldDeclaringClass" phase="start" num="61">
7634 <synopsis>Get Field Declaring Class</synopsis>
7635 <description>
7636 For the field indicated by <code>klass</code> and <code>field</code>
7637 return the class that defined it via <code>declaring_class_ptr</code>.
7638 The declaring class will either be <code>klass</code>, a superclass, or
7639 an implemented interface.
7640 </description>
7641 <origin>jvmdi</origin>
7642 <capabilities>
7643 </capabilities>
7644 <parameters>
7645 <param id="klass">
7646 <jclass field="field"/>
7647 <description>
7648 The class to query.
7649 </description>
7650 </param>
7651 <param id="field">
7652 <jfieldID class="klass"/>
7653 <description>
7654 The field to query.
7655 </description>
7656 </param>
7657 <param id="declaring_class_ptr">
7658 <outptr><jclass/></outptr>
7659 <description>
7660 On return, points to the declaring class
7661 </description>
7662 </param>
7663 </parameters>
7664 <errors>
7665 </errors>
7666 </function>
7667
7668 <function id="GetFieldModifiers" phase="start" num="62">
7669 <synopsis>Get Field Modifiers</synopsis>
7670 <description>
7671 For the field indicated by <code>klass</code> and <code>field</code>
7672 return the access flags via <code>modifiers_ptr</code>.
7673 Access flags are defined in the
7674 <vmspeclink id="ClassFile.doc.html"
7675 name="Class File Format chapter"/>.
7676 </description>
7677 <origin>jvmdi</origin>
7678 <capabilities>
7679 </capabilities>
7680 <parameters>
7681 <param id="klass">
7682 <jclass field="field"/>
7683 <description>
7684 The class to query.
7685 </description>
7686 </param>
7687 <param id="field">
7688 <jfieldID class="klass"/>
7689 <description>
7690 The field to query.
7691 </description>
7692 </param>
7693 <param id="modifiers_ptr">
7694 <outptr><jint/></outptr>
7695 <description>
7696 On return, points to the access flags.
7697 </description>
7698 </param>
7699 </parameters>
7700 <errors>
7701 </errors>
7702 </function>
7703
7704 <function id="IsFieldSynthetic" phase="start" num="63">
7705 <synopsis>Is Field Synthetic</synopsis>
7706 <description>
7707 For the field indicated by <code>klass</code> and <code>field</code>, return a
7708 value indicating whether the field is synthetic via <code>is_synthetic_ptr</code>.
7709 Synthetic fields are generated by the compiler but not present in the
7710 original source code.
7711 </description>
7712 <origin>jvmdi</origin>
7713 <capabilities>
7714 <required id="can_get_synthetic_attribute"></required>
7715 </capabilities>
7716 <parameters>
7717 <param id="klass">
7718 <jclass field="field"/>
7719 <description>
7720 The class of the field to query.
7721 </description>
7722 </param>
7723 <param id="field">
7724 <jfieldID class="klass"/>
7725 <description>
7726 The field to query.
7727 </description>
7728 </param>
7729 <param id="is_synthetic_ptr">
7730 <outptr><jboolean/></outptr>
7731 <description>
7732 On return, points to the boolean result of this function.
7733 </description>
7734 </param>
7735 </parameters>
7736 <errors>
7737 </errors>
7738 </function>
7739
7740 </category>
7741
7742 <category id="method" label="Method">
7743
7744 <intro>
7745 These functions provide information about a method (represented as a
7746 <typelink id="jmethodID"/>) and set how methods are processed.
7747 </intro>
7748
7749 <intro id="obsoleteMethods" label="Obsolete Methods">
7750 The functions <functionlink id="RetransformClasses"/> and
7751 <functionlink id="RedefineClasses"/> can cause new versions
7752 of methods to be installed.
7753 An original version of a method is considered equivalent
7754 to the new version if:
7755 <ul>
7756 <li>their bytecodes are the same except for indices into the
7757 constant pool and </li>
7758 <li>the referenced constants are equal.</li>
7759 </ul>
7760 An original method version which is not equivalent to the
7761 new method version is called obsolete and is assigned a new method ID;
7762 the original method ID now refers to the new method version.
7763 A method ID can be tested for obsolescence with
7764 <functionlink id="IsMethodObsolete"/>.
7765 </intro>
7766
7767 <function id="GetMethodName" phase="start" num="64">
7768 <synopsis>Get Method Name (and Signature)</synopsis>
7769 <description>
7770 For the method indicated by <code>method</code>,
7771 return the method name via <code>name_ptr</code> and method signature via
7772 <code>signature_ptr</code>.
7773 <p/>
7774 Method signatures are defined in the JNI Specification and are referred to as
7775 <vmspeclink id="ClassFile.doc.html#7035"
7776 name="method descriptors"
7777 preposition="in"/>.
7778 Note this is different
7779 than method signatures as defined in the <i>Java Language Specification</i>.
7780 </description>
7781 <origin>jvmdiClone</origin>
7782 <capabilities>
7783 </capabilities>
7784 <parameters>
7785 <param id="method">
7786 <jmethodID/>
7787 <description>
7788 The method to query.
7789 </description>
7790 </param>
7791 <param id="name_ptr">
7792 <allocbuf>
7793 <char/>
7794 <nullok>the name is not returned</nullok>
7795 </allocbuf>
7796 <description>
7797 On return, points to the method name, encoded as a
7798 <internallink id="mUTF">modified UTF-8</internallink> string.
7799 </description>
7800 </param>
7801 <param id="signature_ptr">
7802 <allocbuf>
7803 <char/>
7804 <nullok>the signature is not returned</nullok>
7805 </allocbuf>
7806 <description>
7807 On return, points to the method signature, encoded as a
7808 <internallink id="mUTF">modified UTF-8</internallink> string.
7809 </description>
7810 </param>
7811 <param id="generic_ptr">
7812 <allocbuf>
7813 <char/>
7814 <nullok>the generic signature is not returned</nullok>
7815 </allocbuf>
7816 <description>
7817 On return, points to the generic signature of the method, encoded as a
7818 <internallink id="mUTF">modified UTF-8</internallink> string.
7819 If there is no generic signature attribute for the method, then,
7820 on return, points to <code>NULL</code>.
7821 </description>
7822 </param>
7823 </parameters>
7824 <errors>
7825 </errors>
7826 </function>
7827
7828 <function id="GetMethodDeclaringClass" phase="start" num="65">
7829 <synopsis>Get Method Declaring Class</synopsis>
7830 <description>
7831 For the method indicated by <code>method</code>,
7832 return the class that defined it via <code>declaring_class_ptr</code>.
7833 </description>
7834 <origin>jvmdi</origin>
7835 <capabilities>
7836 </capabilities>
7837 <parameters>
7838 <param id="klass">
7839 <jclass method="method"/>
7840 <description>
7841 The class to query.
7842 </description>
7843 </param>
7844 <param id="method">
7845 <jmethodID class="klass"/>
7846 <description>
7847 The method to query.
7848 </description>
7849 </param>
7850 <param id="declaring_class_ptr">
7851 <outptr><jclass/></outptr>
7852 <description>
7853 On return, points to the declaring class
7854 </description>
7855 </param>
7856 </parameters>
7857 <errors>
7858 </errors>
7859 </function>
7860
7861 <function id="GetMethodModifiers" phase="start" num="66">
7862 <synopsis>Get Method Modifiers</synopsis>
7863 <description>
7864 For the method indicated by <code>method</code>,
7865 return the access flags via <code>modifiers_ptr</code>.
7866 Access flags are defined in the
7867 <vmspeclink id="ClassFile.doc.html"
7868 name="Class File Format chapter"/>.
7869 </description>
7870 <origin>jvmdi</origin>
7871 <capabilities>
7872 </capabilities>
7873 <parameters>
7874 <param id="klass">
7875 <jclass method="method"/>
7876 <description>
7877 The class to query.
7878 </description>
7879 </param>
7880 <param id="method">
7881 <jmethodID class="klass"/>
7882 <description>
7883 The method to query.
7884 </description>
7885 </param>
7886 <param id="modifiers_ptr">
7887 <outptr><jint/></outptr>
7888 <description>
7889 On return, points to the access flags.
7890 </description>
7891 </param>
7892 </parameters>
7893 <errors>
7894 </errors>
7895 </function>
7896
7897 <function id="GetMaxLocals" phase="start" num="68">
7898 <synopsis>Get Max Locals</synopsis>
7899 <description>
7900 For the method indicated by <code>method</code>,
7901 return the number of local variable slots used by the method,
7902 including the local variables used to pass parameters to the
7903 method on its invocation.
7904 <p/>
7905 See <code>max_locals</code> in the
7906 <vmspeclink id="ClassFile.doc.html#1546"
7907 name="Code Attribute section"/>.
7908 </description>
7909 <origin>jvmdi</origin>
7910 <capabilities>
7911 </capabilities>
7912 <parameters>
7913 <param id="klass">
7914 <jclass method="method"/>
7915 <description>
7916 The class to query.
7917 </description>
7918 </param>
7919 <param id="method">
7920 <jmethodID class="klass" native="error"/>
7921 <description>
7922 The method to query.
7923 </description>
7924 </param>
7925 <param id="max_ptr">
7926 <outptr><jint/></outptr>
7927 <description>
7928 On return, points to the maximum number of local slots
7929 </description>
7930 </param>
7931 </parameters>
7932 <errors>
7933 </errors>
7934 </function>
7935
7936 <function id="GetArgumentsSize" phase="start" num="69">
7937 <synopsis>Get Arguments Size</synopsis>
7938 <description>
7939 For the method indicated by <code>method</code>,
7940 return via <code>max_ptr</code> the number of local variable slots used
7941 by the method's arguments.
7942 Note that two-word arguments use two slots.
7943 </description>
7944 <origin>jvmdi</origin>
7945 <capabilities>
7946 </capabilities>
7947 <parameters>
7948 <param id="klass">
7949 <jclass method="method"/>
7950 <description>
7951 The class to query.
7952 </description>
7953 </param>
7954 <param id="method">
7955 <jmethodID class="klass" native="error"/>
7956 <description>
7957 The method to query.
7958 </description>
7959 </param>
7960 <param id="size_ptr">
7961 <outptr><jint/></outptr>
7962 <description>
7963 On return, points to the number of argument slots
7964 </description>
7965 </param>
7966 </parameters>
7967 <errors>
7968 </errors>
7969 </function>
7970
7971 <function id="GetLineNumberTable" phase="start" num="70">
7972 <synopsis>Get Line Number Table</synopsis>
7973 <typedef id="jvmtiLineNumberEntry" label="Line number table entry">
7974 <field id="start_location">
7975 <jlocation/>
7976 <description>
7977 the <datalink id="jlocation"></datalink> where the line begins
7978 </description>
7979 </field>
7980 <field id="line_number">
7981 <jint/>
7982 <description>
7983 the line number
7984 </description>
7985 </field>
7986 </typedef>
7987 <description>
7988 For the method indicated by <code>method</code>,
7989 return a table of source line number entries. The size of the table is
7990 returned via <code>entry_count_ptr</code> and the table itself is
7991 returned via <code>table_ptr</code>.
7992 </description>
7993 <origin>jvmdi</origin>
7994 <capabilities>
7995 <required id="can_get_line_numbers"></required>
7996 </capabilities>
7997 <parameters>
7998 <param id="klass">
7999 <jclass method="method"/>
8000 <description>
8001 The class to query.
8002 </description>
8003 </param>
8004 <param id="method">
8005 <jmethodID class="klass" native="error"/>
8006 <description>
8007 The method to query.
8008 </description>
8009 </param>
8010 <param id="entry_count_ptr">
8011 <outptr><jint/></outptr>
8012 <description>
8013 On return, points to the number of entries in the table
8014 </description>
8015 </param>
8016 <param id="table_ptr">
8017 <allocbuf outcount="entry_count_ptr"><struct>jvmtiLineNumberEntry</struct></allocbuf>
8018 <description>
8019 On return, points to the line number table pointer.
8020 </description>
8021 </param>
8022 </parameters>
8023 <errors>
8024 <error id="JVMTI_ERROR_ABSENT_INFORMATION">
8025 Class information does not include line numbers.
8026 </error>
8027 </errors>
8028 </function>
8029
8030 <function id="GetMethodLocation" phase="start" num="71">
8031 <synopsis>Get Method Location</synopsis>
8032 <description>
8033 For the method indicated by <code>method</code>,
8034 return the beginning and ending addresses through
8035 <code>start_location_ptr</code> and <code>end_location_ptr</code>. In a
8036 conventional byte code indexing scheme,
8037 <code>start_location_ptr</code> will always point to zero
8038 and <code>end_location_ptr</code>
8039 will always point to the byte code count minus one.
8040 </description>
8041 <origin>jvmdi</origin>
8042 <capabilities>
8043 </capabilities>
8044 <parameters>
8045 <param id="klass">
8046 <jclass method="method"/>
8047 <description>
8048 The class to query.
8049 </description>
8050 </param>
8051 <param id="method">
8052 <jmethodID class="klass" native="error"/>
8053 <description>
8054 The method to query.
8055 </description>
8056 </param>
8057 <param id="start_location_ptr">
8058 <outptr><jlocation/></outptr>
8059 <description>
8060 On return, points to the first location, or
8061 <code>-1</code> if location information is not available.
8062 If the information is available and
8063 <functionlink id="GetJLocationFormat"></functionlink>
8064 returns <datalink id="JVMTI_JLOCATION_JVMBCI"></datalink>
8065 then this will always be zero.
8066 </description>
8067 </param>
8068 <param id="end_location_ptr">
8069 <outptr><jlocation/></outptr>
8070 <description>
8071 On return, points to the last location,
8072 or <code>-1</code> if location information is not available.
8073 </description>
8074 </param>
8075 </parameters>
8076 <errors>
8077 <error id="JVMTI_ERROR_ABSENT_INFORMATION">
8078 Class information does not include method sizes.
8079 </error>
8080 </errors>
8081 </function>
8082
8083 <function id="GetLocalVariableTable" num="72">
8084 <synopsis>Get Local Variable Table</synopsis>
8085 <typedef id="jvmtiLocalVariableEntry" label="Local variable table entry">
8086 <field id="start_location">
8087 <jlocation/>
8088 <description>
8089 The code array index where the local variable is first valid
8090 (that is, where it must have a value).
8091 </description>
8092 </field>
8093 <field id="length">
8094 <jint/>
8095 <description>
8096 The length of the valid section for this local variable.
8097 The last code array index where the local variable is valid
8098 is <code>start_location + length</code>.
8099 </description>
8100 </field>
8101 <field id="name">
8102 <allocfieldbuf><char/></allocfieldbuf>
8103 <description>
8104 The local variable name, encoded as a
8105 <internallink id="mUTF">modified UTF-8</internallink> string.
8106 </description>
8107 </field>
8108 <field id="signature">
8109 <allocfieldbuf><char/></allocfieldbuf>
8110 <description>
8111 The local variable's type signature, encoded as a
8112 <internallink id="mUTF">modified UTF-8</internallink> string.
8113 The signature format is the same as that defined in
8114 <vmspeclink id="ClassFile.doc.html#14152"
8115 name="Field Descriptors section"/>
8116 </description>
8117 </field>
8118 <field id="generic_signature">
8119 <allocfieldbuf><char/></allocfieldbuf>
8120 <description>
8121 The local variable's generic signature, encoded as a
8122 <internallink id="mUTF">modified UTF-8</internallink> string.
8123 The value of this field will be <code>NULL</code> for any local
8124 variable which does not have a generic type.
8125 </description>
8126 </field>
8127 <field id="slot">
8128 <jint/>
8129 <description>
8130 The local variable's slot. See <internallink id="local">Local Variables</internallink>.
8131 </description>
8132 </field>
8133 </typedef>
8134 <description>
8135 Return local variable information.
8136 </description>
8137 <origin>jvmdiClone</origin>
8138 <capabilities>
8139 <required id="can_access_local_variables"></required>
8140 </capabilities>
8141 <parameters>
8142 <param id="method">
8143 <jmethodID native="error"/>
8144 <description>
8145 The method to query.
8146 </description>
8147 </param>
8148 <param id="entry_count_ptr">
8149 <outptr><jint/></outptr>
8150 <description>
8151 On return, points to the number of entries in the table
8152 </description>
8153 </param>
8154 <param id="table_ptr">
8155 <allocbuf outcount="entry_count_ptr"><struct>jvmtiLocalVariableEntry</struct></allocbuf>
8156 <description>
8157 On return, points to an array of local variable table entries.
8158 </description>
8159 </param>
8160 </parameters>
8161 <errors>
8162 <error id="JVMTI_ERROR_ABSENT_INFORMATION">
8163 Class information does not include local variable
8164 information.
8165 </error>
8166 </errors>
8167 </function>
8168
8169 <function id="GetBytecodes" phase="start" num="75">
8170 <synopsis>Get Bytecodes</synopsis>
8171 <description>
8172 For the method indicated by <code>method</code>,
8173 return the byte codes that implement the method. The number of
8174 bytecodes is returned via <code>bytecode_count_ptr</code>. The byte codes
8175 themselves are returned via <code>bytecodes_ptr</code>.
8176 </description>
8177 <origin>jvmdi</origin>
8178 <capabilities>
8179 <required id="can_get_bytecodes"></required>
8180 </capabilities>
8181 <parameters>
8182 <param id="klass">
8183 <jclass method="method"/>
8184 <description>
8185 The class to query.
8186 </description>
8187 </param>
8188 <param id="method">
8189 <jmethodID class="klass" native="error"/>
8190 <description>
8191 The method to query.
8192 </description>
8193 </param>
8194 <param id="bytecode_count_ptr">
8195 <outptr><jint/></outptr>
8196 <description>
8197 On return, points to the length of the byte code array
8198 </description>
8199 </param>
8200 <param id="bytecodes_ptr">
8201 <allocbuf outcount="bytecode_count_ptr"><uchar/></allocbuf>
8202 <description>
8203 On return, points to the pointer to the byte code array
8204 </description>
8205 </param>
8206 </parameters>
8207 <errors>
8208 </errors>
8209 </function>
8210
8211 <function id="IsMethodNative" phase="start" num="76">
8212 <synopsis>Is Method Native</synopsis>
8213 <description>
8214 For the method indicated by <code>method</code>, return a
8215 value indicating whether the method is native via <code>is_native_ptr</code>
8216 </description>
8217 <origin>jvmdi</origin>
8218 <capabilities>
8219 </capabilities>
8220 <parameters>
8221 <param id="klass">
8222 <jclass method="method"/>
8223 <description>
8224 The class to query.
8225 </description>
8226 </param>
8227 <param id="method">
8228 <jmethodID class="klass"/>
8229 <description>
8230 The method to query.
8231 </description>
8232 </param>
8233 <param id="is_native_ptr">
8234 <outptr><jboolean/></outptr>
8235 <description>
8236 On return, points to the boolean result of this function.
8237 </description>
8238 </param>
8239 </parameters>
8240 <errors>
8241 </errors>
8242 </function>
8243
8244 <function id="IsMethodSynthetic" phase="start" num="77">
8245 <synopsis>Is Method Synthetic</synopsis>
8246 <description>
8247 For the method indicated by <code>method</code>, return a
8248 value indicating whether the method is synthetic via <code>is_synthetic_ptr</code>.
8249 Synthetic methods are generated by the compiler but not present in the
8250 original source code.
8251 </description>
8252 <origin>jvmdi</origin>
8253 <capabilities>
8254 <required id="can_get_synthetic_attribute"></required>
8255 </capabilities>
8256 <parameters>
8257 <param id="klass">
8258 <jclass method="method"/>
8259 <description>
8260 The class to query.
8261 </description>
8262 </param>
8263 <param id="method">
8264 <jmethodID class="klass"/>
8265 <description>
8266 The method to query.
8267 </description>
8268 </param>
8269 <param id="is_synthetic_ptr">
8270 <outptr><jboolean/></outptr>
8271 <description>
8272 On return, points to the boolean result of this function.
8273 </description>
8274 </param>
8275 </parameters>
8276 <errors>
8277 </errors>
8278 </function>
8279
8280 <function id="IsMethodObsolete" phase="start" num="91">
8281 <synopsis>Is Method Obsolete</synopsis>
8282 <description>
8283 Determine if a method ID refers to an
8284 <internallink id="obsoleteMethods">obsolete</internallink>
8285 method version.
8286 </description>
8287 <origin>jvmdi</origin>
8288 <capabilities>
8289 </capabilities>
8290 <parameters>
8291 <param id="klass">
8292 <jclass method="method"/>
8293 <description>
8294 The class to query.
8295 </description>
8296 </param>
8297 <param id="method">
8298 <jmethodID class="klass"/>
8299 <description>
8300 The method ID to query.
8301 </description>
8302 </param>
8303 <param id="is_obsolete_ptr">
8304 <outptr><jboolean/></outptr>
8305 <description>
8306 On return, points to the boolean result of this function.
8307 </description>
8308 </param>
8309 </parameters>
8310 <errors>
8311 </errors>
8312 </function>
8313
8314 <function id="SetNativeMethodPrefix" jkernel="yes" phase="any" num="73" since="1.1">
8315 <synopsis>Set Native Method Prefix</synopsis>
8316 <description>
8317 This function modifies the failure handling of
8318 native method resolution by allowing retry
8319 with a prefix applied to the name.
8320 When used with the
8321 <eventlink id="ClassFileLoadHook">ClassFileLoadHook
8322 event</eventlink>, it enables native methods to be
8323 <internallink id="bci">instrumented</internallink>.
8324 <p/>
8325 Since native methods cannot be directly instrumented
8326 (they have no bytecodes), they must be wrapped with
8327 a non-native method which can be instrumented.
8328 For example, if we had:
8329 <example>
8330 native boolean foo(int x);</example>
8331 <p/>
8332 We could transform the class file (with the
8333 ClassFileLoadHook event) so that this becomes:
8334 <example>
8335 boolean foo(int x) {
8336 <i>... record entry to foo ...</i>
8337 return wrapped_foo(x);
8338 }
8339
8340 native boolean wrapped_foo(int x);</example>
8341 <p/>
8342 Where foo becomes a wrapper for the actual native method
8343 with the appended prefix "wrapped_". Note that
8344 "wrapped_" would be a poor choice of prefix since it
8345 might conceivably form the name of an existing method
8346 thus something like "$$$MyAgentWrapped$$$_" would be
8347 better but would make these examples less readable.
8348 <p/>
8349 The wrapper will allow data to be collected on the native
8350 method call, but now the problem becomes linking up the
8351 wrapped method with the native implementation.
8352 That is, the method <code>wrapped_foo</code> needs to be
8353 resolved to the native implementation of <code>foo</code>,
8354 which might be:
8355 <example>
8356 Java_somePackage_someClass_foo(JNIEnv* env, jint x)</example>
8357 <p/>
8358 This function allows the prefix to be specified and the
8359 proper resolution to occur.
8360 Specifically, when the standard resolution fails, the
8361 resolution is retried taking the prefix into consideration.
8362 There are two ways that resolution occurs, explicit
8363 resolution with the JNI function <code>RegisterNatives</code>
8364 and the normal automatic resolution. For
8365 <code>RegisterNatives</code>, the VM will attempt this
8366 association:
8367 <example>
8368 method(foo) -> nativeImplementation(foo)</example>
8369 <p/>
8370 When this fails, the resolution will be retried with
8371 the specified prefix prepended to the method name,
8372 yielding the correct resolution:
8373 <example>
8374 method(wrapped_foo) -> nativeImplementation(foo)</example>
8375 <p/>
8376 For automatic resolution, the VM will attempt:
8377 <example>
8378 method(wrapped_foo) -> nativeImplementation(wrapped_foo)</example>
8379 <p/>
8380 When this fails, the resolution will be retried with
8381 the specified prefix deleted from the implementation name,
8382 yielding the correct resolution:
8383 <example>
8384 method(wrapped_foo) -> nativeImplementation(foo)</example>
8385 <p/>
8386 Note that since the prefix is only used when standard
8387 resolution fails, native methods can be wrapped selectively.
8388 <p/>
8389 Since each <jvmti/> environment is independent and
8390 can do its own transformation of the bytecodes, more
8391 than one layer of wrappers may be applied. Thus each
8392 environment needs its own prefix. Since transformations
8393 are applied in order, the prefixes, if applied, will
8394 be applied in the same order.
8395 The order of transformation application is described in
8396 the <eventlink id="ClassFileLoadHook"/> event.
8397 Thus if three environments applied
8398 wrappers, <code>foo</code> might become
8399 <code>$env3_$env2_$env1_foo</code>. But if, say,
8400 the second environment did not apply a wrapper to
8401 <code>foo</code> it would be just
8402 <code>$env3_$env1_foo</code>. To be able to
8403 efficiently determine the sequence of prefixes,
8404 an intermediate prefix is only applied if its non-native
8405 wrapper exists. Thus, in the last example, even though
8406 <code>$env1_foo</code> is not a native method, the
8407 <code>$env1_</code> prefix is applied since
8408 <code>$env1_foo</code> exists.
8409 <p/>
8410 Since the prefixes are used at resolution time
8411 and since resolution may be arbitrarily delayed, a
8412 native method prefix must remain set as long as there
8413 are corresponding prefixed native methods.
8414 </description>
8415 <origin>new</origin>
8416 <capabilities>
8417 <required id="can_set_native_method_prefix"></required>
8418 </capabilities>
8419 <parameters>
8420 <param id="prefix">
8421 <inbuf>
8422 <char/>
8423 <nullok>
8424 any existing prefix in this environment is cancelled
8425 </nullok>
8426 </inbuf>
8427 <description>
8428 The prefix to apply, encoded as a
8429 <internallink id="mUTF">modified UTF-8</internallink> string.
8430 </description>
8431 </param>
8432 </parameters>
8433 <errors>
8434 </errors>
8435 </function>
8436
8437 <function id="SetNativeMethodPrefixes" jkernel="yes" phase="any" num="74" since="1.1">
8438 <synopsis>Set Native Method Prefixes</synopsis>
8439 <description>
8440 For a normal agent, <functionlink id="SetNativeMethodPrefix"/>
8441 will provide all needed native method prefixing.
8442 For a meta-agent that performs multiple independent class
8443 file transformations (for example as a proxy for another
8444 layer of agents) this function allows each transformation
8445 to have its own prefix.
8446 The prefixes are applied in the order supplied and are
8447 processed in the same manor as described for the
8448 application of prefixes from multiple <jvmti/> environments
8449 in <functionlink id="SetNativeMethodPrefix"/>.
8450 <p/>
8451 Any previous prefixes are replaced. Thus, calling this
8452 function with a <paramlink id="prefix_count"/> of <code>0</code>
8453 disables prefixing in this environment.
8454 <p/>
8455 <functionlink id="SetNativeMethodPrefix"/> and this function
8456 are the two ways to set the prefixes.
8457 Calling <code>SetNativeMethodPrefix</code> with
8458 a prefix is the same as calling this function with
8459 <paramlink id="prefix_count"/> of <code>1</code>.
8460 Calling <code>SetNativeMethodPrefix</code> with
8461 <code>NULL</code> is the same as calling this function with
8462 <paramlink id="prefix_count"/> of <code>0</code>.
8463 </description>
8464 <origin>new</origin>
8465 <capabilities>
8466 <required id="can_set_native_method_prefix"></required>
8467 </capabilities>
8468 <parameters>
8469 <param id="prefix_count">
8470 <jint min="0"/>
8471 <description>
8472 The number of prefixes to apply.
8473 </description>
8474 </param>
8475 <param id="prefixes">
8476 <agentbuf>
8477 <char/>
8478 </agentbuf>
8479 <description>
8480 The prefixes to apply for this environment, each encoded as a
8481 <internallink id="mUTF">modified UTF-8</internallink> string.
8482 </description>
8483 </param>
8484 </parameters>
8485 <errors>
8486 </errors>
8487 </function>
8488
8489 </category>
8490
8491 <category id="RawMonitors" label="Raw Monitor">
8492
8493 <function id="CreateRawMonitor" phase="onload" callbacksafe="safe" num="31">
8494 <synopsis>Create Raw Monitor</synopsis>
8495 <description>
8496 Create a raw monitor.
8497 </description>
8498 <origin>jvmdi</origin>
8499 <capabilities>
8500 </capabilities>
8501 <parameters>
8502 <param id="name">
8503 <inbuf><char/></inbuf>
8504 <description>
8505 A name to identify the monitor, encoded as a
8506 <internallink id="mUTF">modified UTF-8</internallink> string.
8507 </description>
8508 </param>
8509 <param id="monitor_ptr">
8510 <outptr><jrawMonitorID/></outptr>
8511 <description>
8512 On return, points to the created monitor.
8513 </description>
8514 </param>
8515 </parameters>
8516 <errors>
8517 </errors>
8518 </function>
8519
8520 <function id="DestroyRawMonitor" phase="onload" callbacksafe="safe" num="32">
8521 <synopsis>Destroy Raw Monitor</synopsis>
8522 <description>
8523 Destroy the raw monitor.
8524 If the monitor being destroyed has been entered by this thread, it will be
8525 exited before it is destroyed.
8526 If the monitor being destroyed has been entered by another thread,
8527 an error will be returned and the monitor will not be destroyed.
8528 </description>
8529 <origin>jvmdi</origin>
8530 <capabilities>
8531 </capabilities>
8532 <parameters>
8533 <param id="monitor">
8534 <jrawMonitorID/>
8535 <description>
8536 The monitor
8537 </description>
8538 </param>
8539 </parameters>
8540 <errors>
8541 <error id="JVMTI_ERROR_NOT_MONITOR_OWNER">
8542 Not monitor owner
8543 </error>
8544 </errors>
8545 </function>
8546
8547 <function id="RawMonitorEnter" phase="any" callbacksafe="safe" impl="innative notrace" num="33">
8548 <synopsis>Raw Monitor Enter</synopsis>
8549 <description>
8550 Gain exclusive ownership of a raw monitor.
8551 The same thread may enter a monitor more then once.
8552 The thread must
8553 <functionlink id="RawMonitorExit">exit</functionlink>
8554 the monitor the same number of times as it is entered.
8555 If a monitor is entered during <code>OnLoad</code> (before attached threads exist)
8556 and has not exited when attached threads come into existence, the enter
8557 is considered to have occurred on the main thread.
8558 </description>
8559 <origin>jvmdi</origin>
8560 <capabilities>
8561 </capabilities>
8562 <parameters>
8563 <param id="monitor">
8564 <jrawMonitorID/>
8565 <description>
8566 The monitor
8567 </description>
8568 </param>
8569 </parameters>
8570 <errors>
8571 </errors>
8572 </function>
8573
8574 <function id="RawMonitorExit" phase="any" callbacksafe="safe" impl="innative notrace" num="34">
8575 <synopsis>Raw Monitor Exit</synopsis>
8576 <description>
8577 Release exclusive ownership of a raw monitor.
8578 </description>
8579 <origin>jvmdi</origin>
8580 <capabilities>
8581 </capabilities>
8582 <parameters>
8583 <param id="monitor">
8584 <jrawMonitorID/>
8585 <description>
8586 The monitor
8587 </description>
8588 </param>
8589 </parameters>
8590 <errors>
8591 <error id="JVMTI_ERROR_NOT_MONITOR_OWNER">
8592 Not monitor owner
8593 </error>
8594 </errors>
8595 </function>
8596
8597 <function id="RawMonitorWait" phase="any" callbacksafe="safe" impl="innative notrace" num="35">
8598 <synopsis>Raw Monitor Wait</synopsis>
8599 <description>
8600 Wait for notification of the raw monitor.
8601 <p/>
8602 Causes the current thread to wait until either another thread calls
8603 <functionlink id="RawMonitorNotify"/> or
8604 <functionlink id="RawMonitorNotifyAll"/>
8605 for the specified raw monitor, or the specified
8606 <paramlink id="millis">timeout</paramlink>
8607 has elapsed.
8608 </description>
8609 <origin>jvmdi</origin>
8610 <capabilities>
8611 </capabilities>
8612 <parameters>
8613 <param id="monitor">
8614 <jrawMonitorID/>
8615 <description>
8616 The monitor
8617 </description>
8618 </param>
8619 <param id="millis">
8620 <jlong/>
8621 <description>
8622 The timeout, in milliseconds. If the timeout is
8623 zero, then real time is not taken into consideration
8624 and the thread simply waits until notified.
8625 </description>
8626 </param>
8627 </parameters>
8628 <errors>
8629 <error id="JVMTI_ERROR_NOT_MONITOR_OWNER">
8630 Not monitor owner
8631 </error>
8632 <error id="JVMTI_ERROR_INTERRUPT">
8633 Wait was interrupted, try again
8634 </error>
8635 </errors>
8636 </function>
8637
8638 <function id="RawMonitorNotify" phase="any" callbacksafe="safe" impl="notrace" num="36">
8639 <synopsis>Raw Monitor Notify</synopsis>
8640 <description>
8641 Notify a single thread waiting on the raw monitor.
8642 </description>
8643 <origin>jvmdi</origin>
8644 <capabilities>
8645 </capabilities>
8646 <parameters>
8647 <param id="monitor">
8648 <jrawMonitorID/>
8649 <description>
8650 The monitor
8651 </description>
8652 </param>
8653 </parameters>
8654 <errors>
8655 <error id="JVMTI_ERROR_NOT_MONITOR_OWNER">
8656 Not monitor owner
8657 </error>
8658 </errors>
8659 </function>
8660
8661 <function id="RawMonitorNotifyAll" phase="any" callbacksafe="safe" impl="notrace" num="37">
8662 <synopsis>Raw Monitor Notify All</synopsis>
8663 <description>
8664 Notify all threads waiting on the raw monitor.
8665 </description>
8666 <origin>jvmdi</origin>
8667 <capabilities>
8668 </capabilities>
8669 <parameters>
8670 <param id="monitor">
8671 <jrawMonitorID/>
8672 <description>
8673 The monitor
8674 </description>
8675 </param>
8676 </parameters>
8677 <errors>
8678 <error id="JVMTI_ERROR_NOT_MONITOR_OWNER">
8679 Not monitor owner
8680 </error>
8681 </errors>
8682 </function>
8683
8684 <elide>
8685 <function id="GetRawMonitorUse" num="118">
8686 <synopsis>Get Raw Monitor Use</synopsis>
8687 <description>
8688 The fields of the <functionlink id="jvmtiMonitorUsage"></functionlink> structure
8689 are filled in with information about usage of the raw monitor.
8690 </description>
8691 <origin>new</origin>
8692 <capabilities>
8693 <required id="can_get_raw_monitor_usage"></required>
8694 </capabilities>
8695 <parameters>
8696 <param id="monitor">
8697 <jrawMonitorID/>
8698 <description>
8699 the raw monitor to query.
8700 </description>
8701 </param>
8702 <param id="info_ptr">
8703 <outptr><struct>jvmtiMonitorUsage</struct></outptr>
8704 <description>
8705 On return, filled with monitor information for the
8706 specified raw monitor.
8707 </description>
8708 </param>
8709 </parameters>
8710 <errors>
8711 </errors>
8712 </function>
8713
8714 <function id="GetRawMonitors" num="119">
8715 <synopsis>Get Raw Monitors</synopsis>
8716 <description>
8717 Return the list of raw monitors.
8718 <p/>
8719 Note: details about each monitor can be examined with
8720 <functionlink id="GetRawMonitorUse"></functionlink>.
8721 </description>
8722 <origin>new</origin>
8723 <capabilities>
8724 <required id="can_get_raw_monitor_usage"></required>
8725 </capabilities>
8726 <parameters>
8727 <param id="monitorCnt">
8728 <outptr><jint/></outptr>
8729 <description>
8730 On return, pointer to the number
8731 of monitors returned in <code>monitors_ptr</code>.
8732 </description>
8733 </param>
8734 <param id="monitors_ptr">
8735 <allocbuf outcount="monitorCnt"><jrawMonitorID/></allocbuf>
8736 <description>
8737 On return, pointer to the monitor list.
8738 </description>
8739 </param>
8740 </parameters>
8741 <errors>
8742 </errors>
8743 </function>
8744 </elide>
8745 </category>
8746
8747 <category id="jniIntercept" label="JNI Function Interception">
8748
8749 <intro>
8750 Provides the ability to intercept and resend
8751 Java Native Interface (JNI) function calls
8752 by manipulating the JNI function table.
8753 See <externallink id="http://java.sun.com/javase/6/docs/guide/jni/spec/functions.html">JNI
8754 Functions</externallink> in the <i>Java Native Interface Specification</i>.
8755 <p/>
8756 The following example illustrates intercepting the
8757 <code>NewGlobalRef</code> JNI call in order to count reference
8758 creation.
8759 <example>
8760 JNIEnv original_jni_Functions;
8761 JNIEnv redirected_jni_Functions;
8762 int my_global_ref_count = 0;
8763
8764 jobject
8765 MyNewGlobalRef(JNIEnv *jni_env, jobject lobj) {
8766 ++my_global_ref_count;
8767 return originalJNIFunctions-&gt;NewGlobalRef(env, lobj);
8768 }
8769
8770 void
8771 myInit() {
8772 jvmtiError err;
8773
8774 err = (*jvmti_env)-&gt;GetJNIFunctionTable(jvmti_env, &amp;original_jni_Functions);
8775 if (err != JVMTI_ERROR_NONE) {
8776 die();
8777 }
8778 err = (*jvmti_env)-&gt;GetJNIFunctionTable(jvmti_env, &amp;redirected_jni_Functions);
8779 if (err != JVMTI_ERROR_NONE) {
8780 die();
8781 }
8782 redirectedJNIFunctions-&gt;NewGlobalRef = MyNewGlobalRef;
8783 err = (*jvmti_env)-&gt;SetJNIFunctionTable(jvmti_env, redirected_jni_Functions);
8784 if (err != JVMTI_ERROR_NONE) {
8785 die();
8786 }
8787 }
8788 </example>
8789 Sometime after <code>myInit</code> is called the user's JNI
8790 code is executed which makes the call to create a new global
8791 reference. Instead of going to the normal JNI implementation
8792 the call goes to <code>myNewGlobalRef</code>. Note that a
8793 copy of the original function table is kept so that the normal
8794 JNI function can be called after the data is collected.
8795 Note also that any JNI functions which are not overwritten
8796 will behave normally.
8797 <todo>
8798 check that the example compiles and executes.
8799 </todo>
8800 </intro>
8801
8802 <function id="SetJNIFunctionTable" phase="start" num="120">
8803 <synopsis>Set JNI Function Table</synopsis>
8804 <description>
8805 Set the JNI function table
8806 in all current and future JNI environments.
8807 As a result, all future JNI calls are directed to the specified functions.
8808 Use <functionlink id="GetJNIFunctionTable"></functionlink> to get the
8809 function table to pass to this function.
8810 For this function to take effect the the updated table entries must be
8811 used by the JNI clients.
8812 Since the table is defined <code>const</code> some compilers may optimize
8813 away the access to the table, thus preventing this function from taking
8814 effect.
8815 The table is copied--changes to the local copy of the
8816 table have no effect.
8817 This function affects only the function table, all other aspects of the environment are
8818 unaffected.
8819 See the examples <internallink id="jniIntercept">above</internallink>.
8820 </description>
8821 <origin>new</origin>
8822 <capabilities>
8823 </capabilities>
8824 <parameters>
8825 <param id="function_table">
8826 <inptr>
8827 <struct>jniNativeInterface</struct>
8828 </inptr>
8829 <description>
8830 Points to the new JNI function table.
8831 </description>
8832 </param>
8833 </parameters>
8834 <errors>
8835 </errors>
8836 </function>
8837
8838 <function id="GetJNIFunctionTable" phase="start" num="121">
8839 <synopsis>Get JNI Function Table</synopsis>
8840 <description>
8841 Get the JNI function table.
8842 The JNI function table is copied into allocated memory.
8843 If <functionlink id="SetJNIFunctionTable"></functionlink>
8844 has been called, the modified (not the original) function
8845 table is returned.
8846 Only the function table is copied, no other aspects of the environment
8847 are copied.
8848 See the examples <internallink id="jniIntercept">above</internallink>.
8849 </description>
8850 <origin>new</origin>
8851 <capabilities>
8852 </capabilities>
8853 <parameters>
8854 <param id="function_table">
8855 <allocbuf>
8856 <struct>jniNativeInterface</struct>
8857 </allocbuf>
8858 <description>
8859 On return, <code>*function_table</code>
8860 points a newly allocated copy of the JNI function table.
8861 </description>
8862 </param>
8863 </parameters>
8864 <errors>
8865 </errors>
8866 </function>
8867
8868 </category>
8869
8870 <category id="eventManagement" label="Event Management">
8871
8872 <function id="SetEventCallbacks" jkernel="yes" phase="onload" num="122">
8873 <synopsis>Set Event Callbacks</synopsis>
8874 <description>
8875 Set the functions to be called for each event.
8876 The callbacks are specified by supplying a replacement function table.
8877 The function table is copied--changes to the local copy of the
8878 table have no effect.
8879 This is an atomic action, all callbacks are set at once.
8880 No events are sent before this function is called.
8881 When an entry is <code>NULL</code> or when the event is beyond
8882 <paramlink id="size_of_callbacks"></paramlink> no event is sent.
8883 Details on events are
8884 described <internallink id="EventSection">later</internallink> in this document.
8885 An event must be enabled and have a callback in order to be
8886 sent--the order in which this function and
8887 <functionlink id="SetEventNotificationMode"></functionlink>
8888 are called does not affect the result.
8889 </description>
8890 <origin>new</origin>
8891 <capabilities>
8892 </capabilities>
8893 <parameters>
8894 <param id="callbacks">
8895 <inptr>
8896 <struct>jvmtiEventCallbacks</struct>
8897 <nullok>remove the existing callbacks</nullok>
8898 </inptr>
8899 <description>
8900 The new event callbacks.
8901 </description>
8902 </param>
8903 <param id="size_of_callbacks">
8904 <jint min="0"/>
8905 <description>
8906 <code>sizeof(jvmtiEventCallbacks)</code>--for version
8907 compatibility.
8908 </description>
8909 </param>
8910 </parameters>
8911 <errors>
8912 </errors>
8913 </function>
8914
8915 <function id="SetEventNotificationMode" jkernel="yes" phase="onload" num="2">
8916 <synopsis>Set Event Notification Mode</synopsis>
8917 <description>
8918 Control the generation of events.
8919 <constants id="jvmtiEventMode" label="Event Enable/Disable" kind="enum">
8920 <constant id="JVMTI_ENABLE" num="1">
8921 If <paramlink id="mode"></paramlink> is <code>JVMTI_ENABLE</code>,
8922 the event <paramlink id="event_type"></paramlink> will be enabled
8923 </constant>
8924 <constant id="JVMTI_DISABLE" num="0">
8925 If <paramlink id="mode"></paramlink> is <code>JVMTI_DISABLE</code>,
8926 the event <paramlink id="event_type"></paramlink> will be disabled
8927 </constant>
8928 </constants>
8929 If <code>thread</code> is <code>NULL</code>,
8930 the event is enabled or disabled globally; otherwise, it is
8931 enabled or disabled for a particular thread.
8932 An event is generated for
8933 a particular thread if it is enabled either at the thread or global
8934 levels.
8935 <p/>
8936 See <internallink id="EventIndex">below</internallink> for information on specific events.
8937 <p/>
8938 The following events cannot be controlled at the thread
8939 level through this function.
8940 <ul>
8941 <li><eventlink id="VMInit"></eventlink></li>
8942 <li><eventlink id="VMStart"></eventlink></li>
8943 <li><eventlink id="VMDeath"></eventlink></li>
8944 <li><eventlink id="ThreadStart"></eventlink></li>
8945 <li><eventlink id="CompiledMethodLoad"></eventlink></li>
8946 <li><eventlink id="CompiledMethodUnload"></eventlink></li>
8947 <li><eventlink id="DynamicCodeGenerated"></eventlink></li>
8948 <li><eventlink id="DataDumpRequest"></eventlink></li>
8949 </ul>
8950 <p/>
8951 Initially, no events are enabled at either the thread level
8952 or the global level.
8953 <p/>
8954 Any needed capabilities (see Event Enabling Capabilities below) must be possessed
8955 before calling this function.
8956 <p/>
8957 Details on events are
8958 described <internallink id="EventSection">below</internallink>.
8959 </description>
8960 <origin>jvmdiClone</origin>
8961 <eventcapabilities></eventcapabilities>
8962 <parameters>
8963 <param id="mode">
8964 <enum>jvmtiEventMode</enum>
8965 <description>
8966 <code>JVMTI_ENABLE</code> or <code>JVMTI_DISABLE</code>
8967 </description>
8968 </param>
8969 <param id="event_type">
8970 <enum>jvmtiEvent</enum>
8971 <description>
8972 the event to control
8973 </description>
8974 </param>
8975 <param id="event_thread">
8976 <ptrtype>
8977 <jthread impl="noconvert"/>
8978 <nullok>event is controlled at the global level</nullok>
8979 </ptrtype>
8980 <description>
8981 The thread to control
8982 </description>
8983 </param>
8984 <param id="...">
8985 <varargs/>
8986 <description>
8987 for future expansion
8988 </description>
8989 </param>
8990 </parameters>
8991 <errors>
8992 <error id="JVMTI_ERROR_INVALID_THREAD">
8993 <paramlink id="event_thread"/> is non-<code>NULL</code> and is not a valid thread.
8994 </error>
8995 <error id="JVMTI_ERROR_THREAD_NOT_ALIVE">
8996 <paramlink id="event_thread"/> is non-<code>NULL</code> and is not live (has not been started or is now dead).
8997 </error>
8998 <error id="JVMTI_ERROR_ILLEGAL_ARGUMENT">
8999 thread level control was attempted on events which do not
9000 permit thread level control.
9001 </error>
9002 <error id="JVMTI_ERROR_MUST_POSSESS_CAPABILITY">
9003 The Required Event Enabling Capability is not possessed.
9004 </error>
9005 </errors>
9006 </function>
9007
9008 <function id="GenerateEvents" num="123">
9009 <synopsis>Generate Events</synopsis>
9010 <description>
9011 Generate events to represent the current state of the VM.
9012 For example, if <paramlink id="event_type"/> is
9013 <code>JVMTI_EVENT_COMPILED_METHOD_LOAD</code>,
9014 a <eventlink id="CompiledMethodLoad"></eventlink> event will be
9015 sent for each currently compiled method.
9016 Methods that were loaded and now have been unloaded are not sent.
9017 The history of what events have previously been sent does not
9018 effect what events are sent by this function--for example,
9019 all currently compiled methods
9020 will be sent each time this function is called.
9021 <p/>
9022 This function is useful when
9023 events may have been missed due to the agent attaching after program
9024 execution begins; this function generates the missed events.
9025 <p/>
9026 Attempts to execute Java programming language code or
9027 JNI functions may be paused until this function returns -
9028 so neither should be called from the thread sending the event.
9029 This function returns only after the missed events have been
9030 sent, processed and have returned.
9031 The event may be sent on a different thread than the thread
9032 on which the event occurred.
9033 The callback for the event must be set with
9034 <functionlink id="SetEventCallbacks"></functionlink>
9035 and the event must be enabled with
9036 <functionlink id="SetEventNotificationMode"></functionlink>
9037 or the events will not occur.
9038 If the VM no longer has the information to generate some or
9039 all of the requested events, the events are simply not sent -
9040 no error is returned.
9041 <p/>
9042 Only the following events are supported:
9043 <ul>
9044 <li><eventlink id="CompiledMethodLoad"></eventlink></li>
9045 <li><eventlink id="DynamicCodeGenerated"></eventlink></li>
9046 </ul>
9047 </description>
9048 <origin>new</origin>
9049 <capabilities>
9050 <capability id="can_generate_compiled_method_load_events"></capability>
9051 </capabilities>
9052 <parameters>
9053 <param id="event_type">
9054 <enum>jvmtiEvent</enum>
9055 <description>
9056 The type of event to generate. Must be one of these:
9057 <ul>
9058 <li><eventlink id="CompiledMethodLoad"><code>JVMTI_EVENT_COMPILED_METHOD_LOAD</code></eventlink></li>
9059 <li><eventlink id="DynamicCodeGenerated"><code>JVMTI_EVENT_DYNAMIC_CODE_GENERATED</code></eventlink></li>
9060 </ul>
9061 </description>
9062 </param>
9063 </parameters>
9064 <errors>
9065 <error id="JVMTI_ERROR_MUST_POSSESS_CAPABILITY">
9066 <paramlink id="event_type"/> is
9067 <eventlink id="CompiledMethodLoad"><code>JVMTI_EVENT_COMPILED_METHOD_LOAD</code></eventlink>
9068 and <fieldlink id="can_generate_compiled_method_load_events" struct="jvmtiCapabilities"></fieldlink>
9069 is <code>false</code>.
9070 </error>
9071 <error id="JVMTI_ERROR_ILLEGAL_ARGUMENT">
9072 <paramlink id="event_type"/> is other than
9073 <eventlink id="CompiledMethodLoad"><code>JVMTI_EVENT_COMPILED_METHOD_LOAD</code></eventlink>
9074 or <eventlink id="DynamicCodeGenerated"><code>JVMTI_EVENT_DYNAMIC_CODE_GENERATED</code></eventlink>.
9075 </error>
9076 </errors>
9077 </function>
9078
9079 </category>
9080
9081 <category id="extension" label="Extension Mechanism">
9082
9083 <intro>
9084 These functions
9085 allow a <jvmti/> implementation to provide functions and events
9086 beyond those defined in this specification.
9087 <p/>
9088 Both extension functions and extension events have parameters
9089 each of which has a 'type' and 'kind' chosen from the following tables:
9090
9091 <constants id="jvmtiParamTypes" label="Extension Function/Event Parameter Types" kind="enum">
9092 <constant id="JVMTI_TYPE_JBYTE" num="101">
9093 Java programming language primitive type - <code>byte</code>.
9094 JNI type <code>jbyte</code>.
9095 </constant>
9096 <constant id="JVMTI_TYPE_JCHAR" num="102">
9097 Java programming language primitive type - <code>char</code>.
9098 JNI type <code>jchar</code>.
9099 </constant>
9100 <constant id="JVMTI_TYPE_JSHORT" num="103">
9101 Java programming language primitive type - <code>short</code>.
9102 JNI type <code>jshort</code>.
9103 </constant>
9104 <constant id="JVMTI_TYPE_JINT" num="104">
9105 Java programming language primitive type - <code>int</code>.
9106 JNI type <datalink id="jint"></datalink>.
9107 </constant>
9108 <constant id="JVMTI_TYPE_JLONG" num="105">
9109 Java programming language primitive type - <code>long</code>.
9110 JNI type <datalink id="jlong"></datalink>.
9111 </constant>
9112 <constant id="JVMTI_TYPE_JFLOAT" num="106">
9113 Java programming language primitive type - <code>float</code>.
9114 JNI type <datalink id="jfloat"></datalink>.
9115 </constant>
9116 <constant id="JVMTI_TYPE_JDOUBLE" num="107">
9117 Java programming language primitive type - <code>double</code>.
9118 JNI type <datalink id="jdouble"></datalink>.
9119 </constant>
9120 <constant id="JVMTI_TYPE_JBOOLEAN" num="108">
9121 Java programming language primitive type - <code>boolean</code>.
9122 JNI type <datalink id="jboolean"></datalink>.
9123 </constant>
9124 <constant id="JVMTI_TYPE_JOBJECT" num="109">
9125 Java programming language object type - <code>java.lang.Object</code>.
9126 JNI type <datalink id="jobject"></datalink>.
9127 Returned values are JNI local references and must be managed.
9128 </constant>
9129 <constant id="JVMTI_TYPE_JTHREAD" num="110">
9130 Java programming language object type - <code>java.lang.Thread</code>.
9131 <jvmti/> type <datalink id="jthread"></datalink>.
9132 Returned values are JNI local references and must be managed.
9133 </constant>
9134 <constant id="JVMTI_TYPE_JCLASS" num="111">
9135 Java programming language object type - <code>java.lang.Class</code>.
9136 JNI type <datalink id="jclass"></datalink>.
9137 Returned values are JNI local references and must be managed.
9138 </constant>
9139 <constant id="JVMTI_TYPE_JVALUE" num="112">
9140 Union of all Java programming language primitive and object types -
9141 JNI type <datalink id="jvalue"></datalink>.
9142 Returned values which represent object types are JNI local references and must be managed.
9143 </constant>
9144 <constant id="JVMTI_TYPE_JFIELDID" num="113">
9145 Java programming language field identifier -
9146 JNI type <datalink id="jfieldID"></datalink>.
9147 </constant>
9148 <constant id="JVMTI_TYPE_JMETHODID" num="114">
9149 Java programming language method identifier -
9150 JNI type <datalink id="jmethodID"></datalink>.
9151 </constant>
9152 <constant id="JVMTI_TYPE_CCHAR" num="115">
9153 C programming language type - <code>char</code>.
9154 </constant>
9155 <constant id="JVMTI_TYPE_CVOID" num="116">
9156 C programming language type - <code>void</code>.
9157 </constant>
9158 <constant id="JVMTI_TYPE_JNIENV" num="117">
9159 JNI environment - <code>JNIEnv</code>.
9160 Should be used with the correct <datalink id="jvmtiParamKind"/> to make it a pointer type.
9161 </constant>
9162 </constants>
9163
9164 <constants id="jvmtiParamKind" label="Extension Function/Event Parameter Kinds" kind="enum">
9165 <constant id="JVMTI_KIND_IN" num="91">
9166 Ingoing argument - <code>foo</code>.
9167 </constant>
9168 <constant id="JVMTI_KIND_IN_PTR" num="92">
9169 Ingoing pointer argument - <code>const foo*</code>.
9170 </constant>
9171 <constant id="JVMTI_KIND_IN_BUF" num="93">
9172 Ingoing array argument - <code>const foo*</code>.
9173 </constant>
9174 <constant id="JVMTI_KIND_ALLOC_BUF" num="94">
9175 Outgoing allocated array argument - <code>foo**</code>.
9176 Free with <code>Deallocate</code>.
9177 </constant>
9178 <constant id="JVMTI_KIND_ALLOC_ALLOC_BUF" num="95">
9179 Outgoing allocated array of allocated arrays argument - <code>foo***</code>.
9180 Free with <code>Deallocate</code>.
9181 </constant>
9182 <constant id="JVMTI_KIND_OUT" num="96">
9183 Outgoing argument - <code>foo*</code>.
9184 </constant>
9185 <constant id="JVMTI_KIND_OUT_BUF" num="97">
9186 Outgoing array argument (pre-allocated by agent) - <code>foo*</code>.
9187 Do not <code>Deallocate</code>.
9188 </constant>
9189 </constants>
9190
9191 </intro>
9192
9193 <typedef id="jvmtiParamInfo" label="Extension Function/Event Parameter Info">
9194 <field id="name">
9195 <allocfieldbuf><char/></allocfieldbuf>
9196 <description>
9197 The parameter name, encoded as a
9198 <internallink id="mUTF">modified UTF-8</internallink> string
9199 </description>
9200 </field>
9201 <field id="kind">
9202 <enum>jvmtiParamKind</enum>
9203 <description>
9204 The kind of the parameter - type modifiers
9205 </description>
9206 </field>
9207 <field id="base_type">
9208 <enum>jvmtiParamTypes</enum>
9209 <description>
9210 The base type of the parameter - modified by <code>kind</code>
9211 </description>
9212 </field>
9213 <field id="null_ok">
9214 <jboolean/>
9215 <description>
9216 Is a <code>NULL</code> argument permitted? Applies only to pointer and object types.
9217 </description>
9218 </field>
9219 </typedef>
9220
9221 <callback id="jvmtiExtensionFunction">
9222 <enum>jvmtiError</enum>
9223 <synopsis>Extension Function</synopsis>
9224 <description>
9225 This is the implementation-specific extension function.
9226 </description>
9227 <parameters>
9228 <param id="jvmti_env">
9229 <outptr>
9230 <struct>jvmtiEnv</struct>
9231 </outptr>
9232 <description>
9233 The <jvmti/> environment is the only fixed parameter for extension functions.
9234 </description>
9235 </param>
9236 <param id="...">
9237 <varargs/>
9238 <description>
9239 The extension function-specific parameters
9240 </description>
9241 </param>
9242 </parameters>
9243 </callback>
9244
9245 <function id="GetExtensionFunctions" phase="onload" num="124">
9246 <synopsis>Get Extension Functions</synopsis>
9247
9248 <typedef id="jvmtiExtensionFunctionInfo" label="Extension Function Info">
9249 <field id="func">
9250 <ptrtype>
9251 <struct>jvmtiExtensionFunction</struct>
9252 </ptrtype>
9253 <description>
9254 The actual function to call
9255 </description>
9256 </field>
9257 <field id="id">
9258 <allocfieldbuf><char/></allocfieldbuf>
9259 <description>
9260 The identifier for the extension function, encoded as a
9261 <internallink id="mUTF">modified UTF-8</internallink> string.
9262 Uses package name conventions.
9263 For example, <code>com.sun.hotspot.bar</code>
9264 </description>
9265 </field>
9266 <field id="short_description">
9267 <allocfieldbuf><char/></allocfieldbuf>
9268 <description>
9269 A one sentence description of the function, encoded as a
9270 <internallink id="mUTF">modified UTF-8</internallink> string.
9271 </description>
9272 </field>
9273 <field id="param_count">
9274 <jint/>
9275 <description>
9276 The number of parameters excluding <code>jvmtiEnv *jvmti_env</code>
9277 </description>
9278 </field>
9279 <field id="params">
9280 <allocfieldbuf outcount="param_count">
9281 <struct>jvmtiParamInfo</struct>
9282 </allocfieldbuf>
9283 <description>
9284 Array of
9285 <fieldlink id="param_count" struct="jvmtiExtensionFunctionInfo"></fieldlink>
9286 parameters (<code>jvmtiEnv *jvmti_env</code> excluded)
9287 </description>
9288 </field>
9289 <field id="error_count">
9290 <jint/>
9291 <description>
9292 The number of possible error returns (excluding universal errors)
9293 </description>
9294 </field>
9295 <field id="errors">
9296 <allocfieldbuf outcount="error_count">
9297 <enum>jvmtiError</enum>
9298 </allocfieldbuf>
9299 <description>
9300 Array of <fieldlink id="error_count" struct="jvmtiExtensionFunctionInfo"></fieldlink>
9301 possible errors
9302 </description>
9303 </field>
9304 </typedef>
9305
9306 <description>
9307 Returns the set of extension functions.
9308 </description>
9309 <origin>new</origin>
9310 <capabilities>
9311 </capabilities>
9312 <parameters>
9313 <param id="extension_count_ptr">
9314 <outptr><jint/></outptr>
9315 <description>
9316 On return, points to the number of extension functions
9317 </description>
9318 </param>
9319 <param id="extensions">
9320 <allocbuf outcount="extension_count_ptr"><struct>jvmtiExtensionFunctionInfo</struct></allocbuf>
9321 <description>
9322 Returns an array of extension function info, one per function
9323 </description>
9324 </param>
9325 </parameters>
9326 <errors>
9327 </errors>
9328 </function>
9329
9330 <function id="GetExtensionEvents" phase="onload" num="125">
9331 <synopsis>Get Extension Events</synopsis>
9332
9333 <typedef id="jvmtiExtensionEventInfo" label="Extension Event Info">
9334 <field id="extension_event_index">
9335 <jint/>
9336 <description>
9337 The identifying index of the event
9338 </description>
9339 </field>
9340 <field id="id">
9341 <allocfieldbuf><char/></allocfieldbuf>
9342 <description>
9343 The identifier for the extension event, encoded as a
9344 <internallink id="mUTF">modified UTF-8</internallink> string.
9345 Uses package name conventions.
9346 For example, <code>com.sun.hotspot.bar</code>
9347 </description>
9348 </field>
9349 <field id="short_description">
9350 <allocfieldbuf><char/></allocfieldbuf>
9351 <description>
9352 A one sentence description of the event, encoded as a
9353 <internallink id="mUTF">modified UTF-8</internallink> string.
9354 </description>
9355 </field>
9356 <field id="param_count">
9357 <jint/>
9358 <description>
9359 The number of parameters excluding <code>jvmtiEnv *jvmti_env</code>
9360 </description>
9361 </field>
9362 <field id="params">
9363 <allocfieldbuf outcount="param_count">
9364 <struct>jvmtiParamInfo</struct>
9365 </allocfieldbuf>
9366 <description>
9367 Array of
9368 <fieldlink id="param_count" struct="jvmtiExtensionEventInfo"></fieldlink>
9369 parameters (<code>jvmtiEnv *jvmti_env</code> excluded)
9370 </description>
9371 </field>
9372 </typedef>
9373
9374 <description>
9375 Returns the set of extension events.
9376 </description>
9377 <origin>new</origin>
9378 <capabilities>
9379 </capabilities>
9380 <parameters>
9381 <param id="extension_count_ptr">
9382 <outptr><jint/></outptr>
9383 <description>
9384 On return, points to the number of extension events
9385 </description>
9386 </param>
9387 <param id="extensions">
9388 <allocbuf outcount="extension_count_ptr"><struct>jvmtiExtensionEventInfo</struct></allocbuf>
9389 <description>
9390 Returns an array of extension event info, one per event
9391 </description>
9392 </param>
9393 </parameters>
9394 <errors>
9395 </errors>
9396 </function>
9397
9398 <callback id="jvmtiExtensionEvent">
9399 <void/>
9400 <synopsis>Extension Event</synopsis>
9401 <description>
9402 This is the implementation-specific event.
9403 The event handler is set with
9404 <functionlink id="SetExtensionEventCallback"/>.
9405 <p/>
9406 Event handlers for extension events must be declared varargs to match this definition.
9407 Failure to do so could result in calling convention mismatch and undefined behavior
9408 on some platforms.
9409 <p/>
9410 For example, if the <code>jvmtiParamInfo</code>
9411 returned by <functionlink id="GetExtensionEvents"/> indicates that
9412 there is a <code>jint</code> parameter, the event handler should be
9413 declared:
9414 <example>
9415 void JNICALL myHandler(jvmtiEnv* jvmti_env, jint myInt, ...)
9416 </example>
9417 Note the terminal "<code>...</code>" which indicates varargs.
9418 </description>
9419 <parameters>
9420 <param id="jvmti_env">
9421 <outptr>
9422 <struct>jvmtiEnv</struct>
9423 </outptr>
9424 <description>
9425 The <jvmti/> environment is the only fixed parameter for extension events.
9426 </description>
9427 </param>
9428 <param id="...">
9429 <varargs/>
9430 <description>
9431 The extension event-specific parameters
9432 </description>
9433 </param>
9434 </parameters>
9435 </callback>
9436
9437 <function id="SetExtensionEventCallback" phase="onload" num="126">
9438 <synopsis>Set Extension Event Callback</synopsis>
9439
9440 <description>
9441 Sets the callback function for an extension event and
9442 enables the event. Or, if the callback is <code>NULL</code>, disables
9443 the event. Note that unlike standard events, setting
9444 the callback and enabling the event are a single operation.
9445 </description>
9446 <origin>new</origin>
9447 <capabilities>
9448 </capabilities>
9449 <parameters>
9450 <param id="extension_event_index">
9451 <jint/>
9452 <description>
9453 Identifies which callback to set.
9454 This index is the
9455 <fieldlink id="extension_event_index" struct="jvmtiExtensionEventInfo"></fieldlink>
9456 field of
9457 <datalink id="jvmtiExtensionEventInfo"/>.
9458 </description>
9459 </param>
9460 <param id="callback">
9461 <ptrtype>
9462 <struct>jvmtiExtensionEvent</struct>
9463 <nullok>disable the event</nullok>
9464 </ptrtype>
9465 <description>
9466 If <code>callback</code> is non-<code>NULL</code>,
9467 set <code>callback</code> to be the event callback function
9468 and enable the event.
9469 </description>
9470 </param>
9471 </parameters>
9472 <errors>
9473 <error id="JVMTI_ERROR_ILLEGAL_ARGUMENT">
9474 <paramlink id="extension_event_index"/> is not an
9475 <fieldlink id="extension_event_index"
9476 struct="jvmtiExtensionEventInfo"/>
9477 returned by
9478 <functionlink id="GetExtensionEvents"/>
9479 </error>
9480 </errors>
9481 </function>
9482
9483 </category>
9484
9485 <category id="capability" label="Capability">
9486
9487 <intro>
9488 The capabilities functions allow you to change the
9489 functionality available to <jvmti/>--that is,
9490 which <jvmti/>
9491 functions can be called, what events can be generated,
9492 and what functionality these events and functions can
9493 provide.
9494 <p/>
9495 The "Capabilities" section of each function and event describe which
9496 capabilities, if any, they are associated with. "Required Functionality"
9497 means it is available for use and no capabilities must be added to use it.
9498 "Optional Functionality" means the agent must possess the capability
9499 before it can be used.
9500 To possess a capability, the agent must
9501 <functionlink id="AddCapabilities">add the capability</functionlink>.
9502 "Optional Features" describe capabilities which,
9503 if added, extend the feature set.
9504 <p/>
9505 The potentially available capabilities of each <jvmti/> implementation are different.
9506 Depending on the implementation, a capability:
9507 <ul>
9508 <li>may never be added</li>
9509 <li>may be added in either the <code>OnLoad</code> or live phase in any environment</li>
9510 <li>may be added only during the <code>OnLoad</code> phase</li>
9511 <li>may be possessed by only one environment at a time</li>
9512 <li>may be possessed by only one environment at a time,
9513 and only during the <code>OnLoad</code> phase</li>
9514 <li>and so on ...</li>
9515 </ul>
9516 Frequently, the addition of a capability may incur a cost in execution speed, start up
9517 time, and/or memory footprint. Note that the overhead of using a capability
9518 is completely different than the overhead of possessing a capability.
9519 Take single stepping as an example. When single stepping is on (that
9520 is, when the event is enabled and thus actively sending events)
9521 the overhead of sending and processing an event
9522 on each instruction is huge in any implementation.
9523 However, the overhead of possessing the capability may be small or large,
9524 depending on the implementation. Also, when and if a capability is potentially
9525 available depends on the implementation. Some examples:
9526 <ul>
9527 <li>One VM might perform all execution by compiling bytecodes into
9528 native code and be unable to generate single step instructions.
9529 In this implementation the capability can not be added.</li>
9530 <li>Another VM may be able to switch execution to a single stepping
9531 interpreter at any time. In this implementation, having the capability has no
9532 overhead and could be added at any time.</li>
9533 <li>Yet another VM might be able to choose a bytecode compiling or single stepping capable interpreted
9534 execution engine at start up, but be unable to switch between them.
9535 In this implementation the capability would need to be added
9536 during the <code>OnLoad</code> phase (before bytecode
9537 execution begins) and would have a large impact on execution speed
9538 even if single stepping was never used.</li>
9539 <li>Still another VM might be able to add an "is single stepping on" check
9540 into compiled bytecodes or a generated interpreter. Again in this implementation
9541 the capability would need to be added during the <code>OnLoad</code> phase but the overhead (a test
9542 and branch on each instruction) would be considerably less.</li>
9543 </ul>
9544 <p/>
9545 Each <jvmti/> <internallink id="environments">environment</internallink>
9546 has its own set of capabilities.
9547 Initially, that set is empty.
9548 Any desired capability must be added.
9549 If possible, capabilities should be added during the <code>OnLoad</code> phase. For most
9550 virtual machines certain capabilities require special set up for
9551 the virtual machine and this set up must happen
9552 during the <code>OnLoad</code> phase, before the virtual machine begins execution.
9553 Once a capability is added, it can
9554 only be removed if explicitly relinquished by the environment.
9555 <p/>
9556 The agent can,
9557 <functionlink id="GetPotentialCapabilities">determine what
9558 capabilities this VM can potentially provide</functionlink>,
9559 <functionlink id="AddCapabilities">add the capabilities
9560 to be used</functionlink>,
9561 <functionlink id="RelinquishCapabilities">release capabilities
9562 which are no longer needed</functionlink>, and
9563 <functionlink id="GetCapabilities">examine the currently available
9564 capabilities</functionlink>.
9565 </intro>
9566
9567 <intro id="capabilityExamples" label="Capability Examples">
9568 For example, a freshly started agent (in the <code>OnLoad</code> function)
9569 wants to enable all possible capabilities.
9570 Note that, in general, this is not advisable as the agent may suffer
9571 a performance penalty for functionality it is not using.
9572 The code might look like this in C:
9573 <example>
9574 jvmtiCapabilities capa;
9575 jvmtiError err;
9576
9577 err = (*jvmti)-&gt;GetPotentialCapabilities(jvmti, &amp;capa);
9578 if (err == JVMTI_ERROR_NONE) {
9579 err = (*jvmti)-&gt;AddCapabilities(jvmti, &amp;capa);
9580 </example>
9581 For example, if an agent wants to check if it can get
9582 the bytecodes of a method (that is, it wants to check
9583 if it previously added this capability and has not
9584 relinquished it), the code might
9585 look like this in C:
9586 <example>
9587 jvmtiCapabilities capa;
9588 jvmtiError err;
9589
9590 err = (*jvmti)-&gt;GetCapabilities(jvmti, &amp;capa);
9591 if (err == JVMTI_ERROR_NONE) {
9592 if (capa.can_get_bytecodes) { ... } }
9593 </example>
9594 </intro>
9595
9596 <capabilitiestypedef id="jvmtiCapabilities" label="The Capabilities Structure">
9597 <description>
9598 The functions in this category use this capabilities structure
9599 which contains boolean flags corresponding to each capability:
9600 </description>
9601 <capabilityfield id="can_tag_objects">
9602 <description>
9603 Can set and get tags, as described in the
9604 <internallink id="Heap">Heap category</internallink>.
9605 </description>
9606 </capabilityfield>
9607 <capabilityfield id="can_generate_field_modification_events">
9608 <description>
9609 Can set watchpoints on field modification -
9610 <functionlink id="SetFieldModificationWatch"></functionlink>
9611 </description>
9612 </capabilityfield>
9613 <capabilityfield id="can_generate_field_access_events">
9614 <description>
9615 Can set watchpoints on field access -
9616 <functionlink id="SetFieldAccessWatch"></functionlink>
9617 </description>
9618 </capabilityfield>
9619 <capabilityfield id="can_get_bytecodes">
9620 <description>
9621 Can get bytecodes of a method <functionlink id="GetBytecodes"></functionlink>
9622 </description>
9623 </capabilityfield>
9624 <capabilityfield id="can_get_synthetic_attribute">
9625 <description>
9626 Can test if a field or method is synthetic -
9627 <functionlink id="IsFieldSynthetic"></functionlink> and
9628 <functionlink id="IsMethodSynthetic"></functionlink>
9629 </description>
9630 </capabilityfield>
9631 <capabilityfield id="can_get_owned_monitor_info">
9632 <description>
9633 Can get information about ownership of monitors -
9634 <functionlink id="GetOwnedMonitorInfo"></functionlink>
9635 </description>
9636 </capabilityfield>
9637 <capabilityfield id="can_get_current_contended_monitor">
9638 <description>
9639 Can <functionlink id="GetCurrentContendedMonitor"></functionlink>
9640 </description>
9641 </capabilityfield>
9642 <capabilityfield id="can_get_monitor_info">
9643 <description>
9644 Can <functionlink id="GetObjectMonitorUsage"></functionlink>
9645 </description>
9646 </capabilityfield>
9647 <capabilityfield id="can_pop_frame">
9648 <description>
9649 Can pop frames off the stack - <functionlink id="PopFrame"></functionlink>
9650 </description>
9651 </capabilityfield>
9652 <capabilityfield id="can_redefine_classes">
9653 <description>
9654 Can redefine classes with <functionlink id="RedefineClasses"/>.
9655 </description>
9656 </capabilityfield>
9657 <capabilityfield id="can_signal_thread">
9658 <description>
9659 Can send stop or interrupt to threads
9660 </description>
9661 </capabilityfield>
9662 <capabilityfield id="can_get_source_file_name">
9663 <description>
9664 Can get the source file name of a class
9665 </description>
9666 </capabilityfield>
9667 <capabilityfield id="can_get_line_numbers">
9668 <description>
9669 Can get the line number table of a method
9670 </description>
9671 </capabilityfield>
9672 <capabilityfield id="can_get_source_debug_extension">
9673 <description>
9674 Can get the source debug extension of a class
9675 </description>
9676 </capabilityfield>
9677 <capabilityfield id="can_access_local_variables">
9678 <description>
9679 Can set and get local variables
9680 </description>
9681 </capabilityfield>
9682 <capabilityfield id="can_maintain_original_method_order">
9683 <description>
9684 Can return methods in the order they occur in the class file
9685 </description>
9686 </capabilityfield>
9687 <capabilityfield id="can_generate_single_step_events">
9688 <description>
9689 Can get <eventlink id="SingleStep">single step</eventlink> events
9690 </description>
9691 </capabilityfield>
9692 <capabilityfield id="can_generate_exception_events">
9693 <description>
9694 Can get <eventlink id="Exception">exception thrown</eventlink> and
9695 <eventlink id="ExceptionCatch">exception catch</eventlink> events
9696 </description>
9697 </capabilityfield>
9698 <capabilityfield id="can_generate_frame_pop_events">
9699 <description>
9700 Can <functionlink id="NotifyFramePop">set</functionlink> and thus get
9701 <eventlink id="FramePop"></eventlink> events
9702 </description>
9703 </capabilityfield>
9704 <capabilityfield id="can_generate_breakpoint_events">
9705 <description>
9706 Can <functionlink id="SetBreakpoint">set</functionlink> and thus get
9707 <eventlink id="Breakpoint"></eventlink> events
9708 </description>
9709 </capabilityfield>
9710 <capabilityfield id="can_suspend">
9711 <description>
9712 Can suspend and resume threads
9713 </description>
9714 </capabilityfield>
9715 <capabilityfield id="can_redefine_any_class">
9716 <description>
9717 Can modify (retransform or redefine) any non-primitive non-array class.
9718 See <functionlink id="IsModifiableClass"/>.
9719 </description>
9720 </capabilityfield>
9721 <capabilityfield id="can_get_current_thread_cpu_time">
9722 <description>
9723 Can <functionlink id="GetCurrentThreadCpuTime">get</functionlink>
9724 current thread CPU time
9725 </description>
9726 </capabilityfield>
9727 <capabilityfield id="can_get_thread_cpu_time">
9728 <description>
9729 Can <functionlink id="GetThreadCpuTime">get</functionlink>
9730 thread CPU time
9731 </description>
9732 </capabilityfield>
9733 <capabilityfield id="can_generate_method_entry_events"
9734 disp1="can_generate" disp2="_method_entry_events"
9735 >
9736 <description>
9737 Can generate method entry events on entering a method
9738 </description>
9739 </capabilityfield>
9740 <capabilityfield id="can_generate_method_exit_events"
9741 disp1="can_generate" disp2="_method_exit_events"
9742 >
9743 <description>
9744 Can generate method exit events on leaving a method
9745 </description>
9746 </capabilityfield>
9747 <capabilityfield id="can_generate_all_class_hook_events"
9748 disp1="can_generate" disp2="_all_class_hook_events"
9749 >
9750 <description>
9751 Can generate ClassFileLoadHook events for every loaded class.
9752 </description>
9753 </capabilityfield>
9754 <capabilityfield id="can_generate_compiled_method_load_events"
9755 disp1="can_generate" disp2="_compiled_method_load_events"
9756 >
9757 <description>
9758 Can generate events when a method is compiled or unloaded
9759 </description>
9760 </capabilityfield>
9761 <capabilityfield id="can_generate_monitor_events"
9762 disp1="can_generate" disp2="_monitor_events"
9763 >
9764 <description>
9765 Can generate events on monitor activity
9766 </description>
9767 </capabilityfield>
9768 <capabilityfield id="can_generate_vm_object_alloc_events"
9769 disp1="can_generate" disp2="_vm_object_alloc_events"
9770 >
9771 <description>
9772 Can generate events on VM allocation of an object
9773 </description>
9774 </capabilityfield>
9775 <capabilityfield id="can_generate_native_method_bind_events"
9776 disp1="can_generate" disp2="_native_method_bind_events"
9777 >
9778 <description>
9779 Can generate events when a native method is bound to its
9780 implementation
9781 </description>
9782 </capabilityfield>
9783 <capabilityfield id="can_generate_garbage_collection_events"
9784 disp1="can_generate" disp2="_garbage_collection_events"
9785 >
9786 <description>
9787 Can generate events when garbage collection begins or ends
9788 </description>
9789 </capabilityfield>
9790 <capabilityfield id="can_generate_object_free_events"
9791 disp1="can_generate" disp2="_object_free_events"
9792 >
9793 <description>
9794 Can generate events when the garbage collector frees an object
9795 </description>
9796 </capabilityfield>
9797 <capabilityfield id="can_force_early_return" since="1.1">
9798 <description>
9799 Can return early from a method, as described in the
9800 <internallink id="ForceEarlyReturn">Force Early Return category</internallink>.
9801 </description>
9802 </capabilityfield>
9803 <capabilityfield id="can_get_owned_monitor_stack_depth_info" since="1.1">
9804 <description>
9805 Can get information about owned monitors with stack depth -
9806 <functionlink id="GetOwnedMonitorStackDepthInfo"></functionlink>
9807 </description>
9808 </capabilityfield>
9809 <capabilityfield id="can_get_constant_pool" since="1.1">
9810 <description>
9811 Can get the constant pool of a class -
9812 <functionlink id="GetConstantPool"></functionlink>
9813 </description>
9814 </capabilityfield>
9815 <capabilityfield id="can_set_native_method_prefix" since="1.1">
9816 <description>
9817 Can set prefix to be applied when native method cannot be resolved -
9818 <functionlink id="SetNativeMethodPrefix"/> and
9819 <functionlink id="SetNativeMethodPrefixes"/>
9820 </description>
9821 </capabilityfield>
9822 <capabilityfield id="can_retransform_classes" since="1.1">
9823 <description>
9824 Can retransform classes with <functionlink id="RetransformClasses"/>.
9825 In addition to the restrictions imposed by the specific
9826 implementation on this capability (see the
9827 <internallink id="capability">Capability</internallink> section),
9828 this capability must be set before the
9829 <eventlink id="ClassFileLoadHook"/> event is enabled for the
9830 first time in this environment.
9831 An environment that possesses this capability at the time that
9832 <code>ClassFileLoadHook</code> is enabled for the first time is
9833 said to be <i>retransformation capable</i>.
9834 An environment that does not possess this capability at the time that
9835 <code>ClassFileLoadHook</code> is enabled for the first time is
9836 said to be <i>retransformation incapable</i>.
9837 </description>
9838 </capabilityfield>
9839 <capabilityfield id="can_retransform_any_class" since="1.1">
9840 <description>
9841 <functionlink id="RetransformClasses"/> can be called on any class
9842 (<fieldlink id="can_retransform_classes" struct="jvmtiCapabilities"/>
9843 must also be set)
9844 </description>
9845 </capabilityfield>
9846 <capabilityfield id="can_generate_resource_exhaustion_heap_events" since="1.1">
9847 <description>
9848 Can generate events when the VM is unable to allocate memory from
9849 the <tm>Java</tm> platform heap.
9850 See <eventlink id="ResourceExhausted"/>.
9851 </description>
9852 </capabilityfield>
9853 <capabilityfield id="can_generate_resource_exhaustion_threads_events" since="1.1">
9854 <description>
9855 Can generate events when the VM is unable to create a thread.
9856 See <eventlink id="ResourceExhausted"/>.
9857 </description>
9858 </capabilityfield>
9859 </capabilitiestypedef>
9860
9861 <function id="GetPotentialCapabilities" jkernel="yes" phase="onload" num="140">
9862 <synopsis>Get Potential Capabilities</synopsis>
9863 <description>
9864 Returns via <paramlink id="capabilities_ptr"></paramlink> the <jvmti/>
9865 features that can potentially be possessed by this environment
9866 at this time.
9867 The returned capabilities differ from the complete set of capabilities
9868 implemented by the VM in two cases: another environment possesses
9869 capabilities that can only be possessed by one environment, or the
9870 current <functionlink id="GetPhase">phase</functionlink> is live,
9871 and certain capabilities can only be added during the <code>OnLoad</code> phase.
9872 The <functionlink id="AddCapabilities"></functionlink> function
9873 may be used to set any or all or these capabilities.
9874 Currently possessed capabilities are included.
9875 <p/>
9876 Typically this function is used in the <code>OnLoad</code> function.
9877 Some virtual machines may allow a limited set of capabilities to be
9878 added in the live phase.
9879 In this case, the set of potentially available capabilities
9880 will likely differ from the <code>OnLoad</code> phase set.
9881 <p/>
9882 See the
9883 <internallink id="capabilityExamples">Capability Examples</internallink>.
9884 </description>
9885 <origin>new</origin>
9886 <capabilities>
9887 </capabilities>
9888 <parameters>
9889 <param id="capabilities_ptr">
9890 <outptr><struct>jvmtiCapabilities</struct></outptr>
9891 <description>
9892 On return, points to the <jvmti/> capabilities that may be added.
9893 </description>
9894 </param>
9895 </parameters>
9896 <errors>
9897 </errors>
9898 </function>
9899
9900 <elide>
9901 <function id="EstimateCostOfCapabilities" phase="onload" num="141">
9902 <synopsis>Estimate Cost Of Capabilities</synopsis>
9903 <description>
9904 <issue>There is strong opposition to this function. The concern is
9905 that it would be difficult or impossible to provide meaningful
9906 numbers, as the amount of impact is conditional on many factors
9907 that a single number could not represent. There is doubt that
9908 conditional implementations would be used or are even a good idea.
9909 The thought is that release documentation for the implementation
9910 would be the best means of exposing this information.
9911 Unless new arguments are presented, I intend to remove this
9912 function in the next revision.
9913 </issue>
9914 <p/>
9915 Return via the <paramlink id="time_impact_ptr"></paramlink> and
9916 <paramlink id="space_impact_ptr"></paramlink> an estimate of the impact
9917 of adding the capabilities pointed to by
9918 <paramlink id="capabilities_ptr"></paramlink>.
9919 The returned estimates are in percentage of additional overhead, thus
9920 a time impact of 100 mean the application might run
9921 at half the speed.
9922 The estimates are very rough approximations and are not guaranteed.
9923 Note also, that the estimates are of the impact of having the
9924 capability available--when and if it is used the impact may be
9925 much greater.
9926 Estimates can be for a single capability or for a set of
9927 capabilities. Note that the costs are not necessarily additive,
9928 adding support for one capability might make another available
9929 for free or conversely having two capabilities at once may
9930 have multiplicative impact.
9931 Estimates are relative to the current set of capabilities -
9932 that is, how much more impact given the currently possessed capabilities.
9933 <p/>
9934 Typically this function is used in the OnLoad function,
9935 some virtual machines may allow a limited set of capabilities to be
9936 added in the live phase.
9937 In this case, the set of potentially available capabilities
9938 will likely differ from the OnLoad phase set.
9939 <p/>
9940 See the
9941 <internallink id="capabilityExamples">Capability Examples</internallink>.
9942 </description>
9943 <origin>new</origin>
9944 <capabilities>
9945 </capabilities>
9946 <parameters>
9947 <param id="capabilities_ptr">
9948 <inptr><struct>jvmtiCapabilities</struct></inptr>
9949 <description>
9950 points to the <jvmti/> capabilities to evaluate.
9951 </description>
9952 </param>
9953 <param id="time_impact_ptr">
9954 <outptr><jint/></outptr>
9955 <description>
9956 On return, points to the estimated percentage increase in
9957 run time if this capability was added.
9958 </description>
9959 </param>
9960 <param id="space_impact_ptr">
9961 <outptr><jint/></outptr>
9962 <description>
9963 On return, points to the estimated percentage increase in
9964 memory space used if this capability was added.
9965 </description>
9966 </param>
9967 </parameters>
9968 <errors>
9969 <error id="JVMTI_ERROR_NOT_AVAILABLE">
9970 The desired capabilities are not even potentially available.
9971 </error>
9972 </errors>
9973 </function>
9974 </elide>
9975
9976 <function id="AddCapabilities" jkernel="yes" phase="onload" num="142">
9977 <synopsis>Add Capabilities</synopsis>
9978 <description>
9979 Set new capabilities by adding the capabilities
9980 whose values are set to one (<code>1</code>) in
9981 <code>*</code><paramlink id="capabilities_ptr"></paramlink>.
9982 All previous capabilities are retained.
9983 Typically this function is used in the <code>OnLoad</code> function.
9984 Some virtual machines may allow a limited set of capabilities to be
9985 added in the live phase.
9986 <p/>
9987 See the
9988 <internallink id="capabilityExamples">Capability Examples</internallink>.
9989 </description>
9990 <origin>new</origin>
9991 <capabilities>
9992 </capabilities>
9993 <parameters>
9994 <param id="capabilities_ptr">
9995 <inptr><struct>jvmtiCapabilities</struct></inptr>
9996 <description>
9997 Points to the <jvmti/> capabilities to add.
9998 </description>
9999 </param>
10000 </parameters>
10001 <errors>
10002 <error id="JVMTI_ERROR_NOT_AVAILABLE">
10003 The desired capabilities are not even potentially available.
10004 </error>
10005 </errors>
10006 </function>
10007
10008
10009 <function id="RelinquishCapabilities" phase="onload" num="143">
10010 <synopsis>Relinquish Capabilities</synopsis>
10011 <description>
10012 Relinquish the capabilities
10013 whose values are set to one (<code>1</code>) in
10014 <code>*</code><paramlink id="capabilities_ptr"></paramlink>.
10015 Some implementations may allow only one environment to have a capability
10016 (see the <internallink id="capability">capability introduction</internallink>).
10017 This function releases capabilities
10018 so that they may be used by other agents.
10019 All other capabilities are retained.
10020 The capability will no longer be present in <functionlink id="GetCapabilities"></functionlink>.
10021 Attempting to relinquish a capability that the agent does not possess is not an error.
10022 <issue>
10023 It is possible for the agent to be actively using capabilities
10024 which are being relinquished. For example, a thread is currently
10025 suspended and can_suspend is being relinquished or an event is currently
10026 enabled and can_generate_whatever is being relinquished.
10027 There are three possible ways we could spec this:
10028 <ul>
10029 <li>relinquish automatically releases them</li>
10030 <li>relinquish checks and returns some error code if held</li>
10031 <li>it is the agent's responsibility and it is not checked</li>
10032 </ul>
10033 One of these should be chosen.
10034 </issue>
10035 </description>
10036 <origin>new</origin>
10037 <capabilities>
10038 </capabilities>
10039 <parameters>
10040 <param id="capabilities_ptr">
10041 <inptr><struct>jvmtiCapabilities</struct></inptr>
10042 <description>
10043 Points to the <jvmti/> capabilities to relinquish.
10044 </description>
10045 </param>
10046 </parameters>
10047 <errors>
10048 </errors>
10049 </function>
10050
10051
10052
10053 <function id="GetCapabilities" jkernel="yes" phase="any" num="89">
10054 <synopsis>Get Capabilities</synopsis>
10055 <description>
10056 Returns via <paramlink id="capabilities_ptr"></paramlink> the optional <jvmti/>
10057 features which this environment currently possesses.
10058 Each possessed capability is indicated by a one (<code>1</code>) in the
10059 corresponding field of the <internallink id="jvmtiCapabilities">capabilities
10060 structure</internallink>.
10061 An environment does not possess a capability unless it has been successfully added with
10062 <functionlink id="AddCapabilities"/>.
10063 An environment only loses possession of a capability if it has been relinquished with
10064 <functionlink id="RelinquishCapabilities"/>. Thus, this function returns the net result
10065 of the <code>AddCapabilities</code> and <code>RelinquishCapabilities</code> calls which
10066 have been made.
10067 <p/>
10068 See the
10069 <internallink id="capabilityExamples">Capability Examples</internallink>.
10070 </description>
10071 <origin>jvmdiClone</origin>
10072 <capabilities>
10073 </capabilities>
10074 <parameters>
10075 <param id="capabilities_ptr">
10076 <outptr><struct>jvmtiCapabilities</struct></outptr>
10077 <description>
10078 On return, points to the <jvmti/> capabilities.
10079 </description>
10080 </param>
10081 </parameters>
10082 <errors>
10083 </errors>
10084 </function>
10085
10086 </category>
10087
10088
10089 <category id="timers" label="Timers">
10090
10091 <intro>
10092 These functions provide timing information.
10093 The resolution at which the time is updated is not specified.
10094 They provides nanosecond precision, but not necessarily nanosecond accuracy.
10095 Details about the timers, such as their maximum values, can be accessed with
10096 the timer information functions.
10097 </intro>
10098
10099 <typedef id="jvmtiTimerInfo" label="Timer Info">
10100 <description>
10101 The information function for each timer returns this data structure.
10102 </description>
10103 <field id="max_value">
10104 <jlong/>
10105 <description>
10106 The maximum value the timer can reach.
10107 After this value is reached the timer wraps back to zero.
10108 This is an unsigned value. If tested or printed as a jlong (signed value)
10109 it may appear to be a negative number.
10110 </description>
10111 </field>
10112 <field id="may_skip_forward">
10113 <jboolean/>
10114 <description>
10115 If true, the timer can be externally adjusted and as a result skip forward.
10116 If false, the timer value will never increase faster than real time.
10117 </description>
10118 </field>
10119 <field id="may_skip_backward">
10120 <jboolean/>
10121 <description>
10122 If true, the timer can be externally adjusted and as a result skip backward.
10123 If false, the timer value will be monotonically increasing.
10124 </description>
10125 </field>
10126 <field id="kind">
10127 <enum>jvmtiTimerKind</enum>
10128 <description>
10129 The kind of timer.
10130 On a platform that does not distinguish between user and system time, <datalink
10131 id="JVMTI_TIMER_TOTAL_CPU"><code>JVMTI_TIMER_TOTAL_CPU</code></datalink>
10132 is returned.
10133 </description>
10134 </field>
10135 <field id="reserved1">
10136 <jlong/>
10137 <description>
10138 Reserved for future use.
10139 </description>
10140 </field>
10141 <field id="reserved2">
10142 <jlong/>
10143 <description>
10144 Reserved for future use.
10145 </description>
10146 </field>
10147 </typedef>
10148
10149 <intro>
10150 Where the timer kind is --
10151
10152 <constants id="jvmtiTimerKind" label="Timer Kinds" kind="enum">
10153 <constant id="JVMTI_TIMER_USER_CPU" num="30">
10154 CPU time that a thread is in user mode.
10155 </constant>
10156 <constant id="JVMTI_TIMER_TOTAL_CPU" num="31">
10157 CPU time that a thread is in user or system mode.
10158 </constant>
10159 <constant id="JVMTI_TIMER_ELAPSED" num="32">
10160 Elapsed time.
10161 </constant>
10162 </constants>
10163 </intro>
10164
10165 <function id="GetCurrentThreadCpuTimerInfo" callbacksafe="safe" impl="innative notrace" phase="start" num="134">
10166 <synopsis>Get Current Thread CPU Timer Information</synopsis>
10167 <description>
10168 Get information about the
10169 <functionlink id="GetCurrentThreadCpuTime"/> timer.
10170 The fields of the <datalink id="jvmtiTimerInfo"/> structure
10171 are filled in with details about the timer.
10172 This information is specific to the platform and the implementation of
10173 <functionlink id="GetCurrentThreadCpuTime"/> and thus
10174 does not vary by thread nor does it vary
10175 during a particular invocation of the VM.
10176 <p/>
10177 Note that the implementations of <functionlink id="GetCurrentThreadCpuTime"/>
10178 and <functionlink id="GetThreadCpuTime"/> may differ, and thus the values
10179 returned by <code>GetCurrentThreadCpuTimerInfo</code>
10180 and <functionlink id="GetThreadCpuTimerInfo"/>
10181 may differ -- see <functionlink id="GetCurrentThreadCpuTime"/> for more information.
10182 </description>
10183 <origin>new</origin>
10184 <capabilities>
10185 <required id="can_get_current_thread_cpu_time">
10186 Can get current thread CPU time.
10187 </required>
10188 </capabilities>
10189 <parameters>
10190 <param id="info_ptr">
10191 <outptr><struct>jvmtiTimerInfo</struct></outptr>
10192 <description>
10193 On return, filled with information describing the time
10194 returned by <functionlink id="GetCurrentThreadCpuTime"/>.
10195 </description>
10196 </param>
10197 </parameters>
10198 <errors>
10199 </errors>
10200 </function>
10201
10202 <function id="GetCurrentThreadCpuTime" callbacksafe="safe" impl="innative notrace" phase="start" num="135">
10203 <synopsis>Get Current Thread CPU Time</synopsis>
10204 <description>
10205 Return the CPU time utilized by the current thread.
10206 <p/>
10207 Note that the <functionlink id="GetThreadCpuTime"/>
10208 function provides CPU time for any thread, including
10209 the current thread. <code>GetCurrentThreadCpuTime</code>
10210 exists to support platforms which cannot
10211 supply CPU time for threads other than the current
10212 thread or which have more accurate information for
10213 the current thread (see
10214 <functionlink id="GetCurrentThreadCpuTimerInfo"/> vs
10215 <functionlink id="GetThreadCpuTimerInfo"/>).
10216 On many platforms this call will be equivalent to:
10217 <example>
10218 GetThreadCpuTime(env, NULL, nanos_ptr)
10219 </example>
10220 </description>
10221 <origin>new</origin>
10222 <capabilities>
10223 <required id="can_get_current_thread_cpu_time">
10224 Can get current thread CPU time.
10225 <p/>
10226 If this capability is enabled after threads have started,
10227 the implementation may choose any time up
10228 to and including the time that the capability is enabled
10229 as the point where CPU time collection starts.
10230 <p/>
10231 This capability must be potentially available on any
10232 platform where
10233 <internallink id="jvmtiCapabilities.can_get_thread_cpu_time"><code>can_get_thread_cpu_time</code></internallink>
10234 is potentially available.
10235 </required>
10236 </capabilities>
10237 <parameters>
10238 <param id="nanos_ptr">
10239 <outptr><jlong/></outptr>
10240 <description>
10241 On return, points to the CPU time used by this thread
10242 in nanoseconds.
10243 This is an unsigned value. If tested or printed as a jlong (signed value)
10244 it may appear to be a negative number.
10245 </description>
10246 </param>
10247 </parameters>
10248 <errors>
10249 </errors>
10250 </function>
10251
10252 <function id="GetThreadCpuTimerInfo" num="136">
10253 <synopsis>Get Thread CPU Timer Information</synopsis>
10254 <description>
10255 Get information about the
10256 <functionlink id="GetThreadCpuTime"/> timer.
10257 The fields of the <datalink id="jvmtiTimerInfo"/> structure
10258 are filled in with details about the timer.
10259 This information is specific to the platform and the implementation of
10260 <functionlink id="GetThreadCpuTime"/> and thus
10261 does not vary by thread nor does it vary
10262 during a particular invocation of the VM.
10263 <p/>
10264 Note that the implementations of <functionlink id="GetCurrentThreadCpuTime"/>
10265 and <functionlink id="GetThreadCpuTime"/> may differ, and thus the values
10266 returned by <functionlink id="GetCurrentThreadCpuTimerInfo"/>
10267 and <code>GetThreadCpuTimerInfo</code>
10268 may differ -- see <functionlink id="GetCurrentThreadCpuTime"/> for more information.
10269 </description>
10270 <origin>new</origin>
10271 <capabilities>
10272 <required id="can_get_thread_cpu_time">
10273 Can get thread CPU time.
10274 </required>
10275 </capabilities>
10276 <parameters>
10277 <param id="info_ptr">
10278 <outptr><struct>jvmtiTimerInfo</struct></outptr>
10279 <description>
10280 On return, filled with information describing the time
10281 returned by <functionlink id="GetThreadCpuTime"/>.
10282 </description>
10283 </param>
10284 </parameters>
10285 <errors>
10286 </errors>
10287 </function>
10288
10289 <function id="GetThreadCpuTime" num="137">
10290 <synopsis>Get Thread CPU Time</synopsis>
10291 <description>
10292 Return the CPU time utilized by the specified thread.
10293 <p/>
10294 Get information about this timer with
10295 <functionlink id="GetThreadCpuTimerInfo"/>.
10296 </description>
10297 <origin>new</origin>
10298 <capabilities>
10299 <required id="can_get_thread_cpu_time">
10300 Can get thread CPU time.
10301 <p/>
10302 If this capability is enabled after threads have started,
10303 the implementation may choose any time up
10304 to and including the time that the capability is enabled
10305 as the point where CPU time collection starts.
10306 </required>
10307 </capabilities>
10308 <parameters>
10309 <param id="thread">
10310 <jthread null="current"/>
10311 <description>
10312 The thread to query.
10313 </description>
10314 </param>
10315 <param id="nanos_ptr">
10316 <outptr><jlong/></outptr>
10317 <description>
10318 On return, points to the CPU time used by the specified thread
10319 in nanoseconds.
10320 This is an unsigned value. If tested or printed as a jlong (signed value)
10321 it may appear to be a negative number.
10322 </description>
10323 </param>
10324 </parameters>
10325 <errors>
10326 </errors>
10327 </function>
10328
10329 <function id="GetTimerInfo" phase="any" callbacksafe="safe" num="138">
10330 <synopsis>Get Timer Information</synopsis>
10331 <description>
10332 Get information about the
10333 <functionlink id="GetTime"/> timer.
10334 The fields of the <datalink id="jvmtiTimerInfo"/> structure
10335 are filled in with details about the timer.
10336 This information will not change during a particular invocation of the VM.
10337 </description>
10338 <origin>new</origin>
10339 <capabilities>
10340 </capabilities>
10341 <parameters>
10342 <param id="info_ptr">
10343 <outptr><struct>jvmtiTimerInfo</struct></outptr>
10344 <description>
10345 On return, filled with information describing the time
10346 returned by <functionlink id="GetTime"/>.
10347 </description>
10348 </param>
10349 </parameters>
10350 <errors>
10351 </errors>
10352 </function>
10353
10354 <function id="GetTime" phase="any" callbacksafe="safe" num="139">
10355 <synopsis>Get Time</synopsis>
10356 <description>
10357 Return the current value of the system timer, in nanoseconds.
10358 <p/>
10359 The value returned represents nanoseconds since some fixed but
10360 arbitrary time (perhaps in the future, so values may be
10361 negative). This function provides nanosecond precision, but not
10362 necessarily nanosecond accuracy. No guarantees are made about
10363 how frequently values change.
10364 <p/>
10365 Get information about this timer with
10366 <functionlink id="GetTimerInfo"/>.
10367 </description>
10368 <origin>new</origin>
10369 <capabilities>
10370 </capabilities>
10371 <parameters>
10372 <param id="nanos_ptr">
10373 <outptr><jlong/></outptr>
10374 <description>
10375 On return, points to the time in nanoseconds.
10376 This is an unsigned value. If tested or printed as a jlong (signed value)
10377 it may appear to be a negative number.
10378 </description>
10379 </param>
10380 </parameters>
10381 <errors>
10382 </errors>
10383 </function>
10384
10385 <function id="GetAvailableProcessors" phase="any" num="144">
10386 <synopsis>Get Available Processors</synopsis>
10387 <description>
10388 Returns the number of processors available to the Java virtual machine.
10389 <p/>
10390 This value may change during a particular invocation of the virtual machine.
10391 Applications that are sensitive to the number of available processors should
10392 therefore occasionally poll this property.
10393 </description>
10394 <origin>new</origin>
10395 <capabilities>
10396 </capabilities>
10397 <parameters>
10398 <param id="processor_count_ptr">
10399 <outptr><jint/></outptr>
10400 <description>
10401 On return, points to the maximum number of processors available to the
10402 virtual machine; never smaller than one.
10403 </description>
10404 </param>
10405 </parameters>
10406 <errors>
10407 </errors>
10408 </function>
10409
10410 </category>
10411
10412
10413 <category id="classLoaderSearch" label="Class Loader Search">
10414
10415 <intro>
10416 These functions allow the agent to add to the locations that a class loader searches for a class.
10417 This is useful for installing instrumentation under the correct class loader.
10418 </intro>
10419
10420 <function id="AddToBootstrapClassLoaderSearch" jkernel="yes" phase="onload" num="149">
10421 <synopsis>Add To Bootstrap Class Loader Search</synopsis>
10422 <description>
10423 This function can be used to cause instrumentation classes to be defined by the
10424 bootstrap class loader. See
10425 <vmspeclink id="ConstantPool.doc.html#79383"
10426 name="Loading Using the Bootstrap Class Loader"
10427 preposition="in"/>.
10428 After the bootstrap
10429 class loader unsuccessfully searches for a class, the specified platform-dependent
10430 search path <paramlink id="segment"/> will be searched as well. Only one segment may be specified in
10431 the <paramlink id="segment"/>. This function may be called multiple times to add multiple segments,
10432 the segments will be searched in the order that this function was called.
10433 <p/>
10434 In the <code>OnLoad</code> phase the function may be used to specify any platform-dependent
10435 search path segment to be searched after the bootstrap class loader unsuccessfully searches
10436 for a class. The segment is typically a directory or JAR file.
10437 <p/>
10438 In the live phase the <paramlink id="segment"/> may be used to specify any platform-dependent
10439 path to a <externallink id="http://java.sun.com/javase/6/docs/guide/jar/jar.html">
10440 JAR file</externallink>. The agent should take care that the JAR file does not
10441 contain any classes or resources other than those to be defined by the bootstrap
10442 class loader for the purposes of instrumentation.
10443 <p/>
10444 The <vmspeclink/> specifies that a subsequent attempt to resolve a symbolic
10445 reference that the Java virtual machine has previously unsuccessfully attempted
10446 to resolve always fails with the same error that was thrown as a result of the
10447 initial resolution attempt. Consequently, if the JAR file contains an entry
10448 that corresponds to a class for which the Java virtual machine has
10449 unsuccessfully attempted to resolve a reference, then subsequent attempts to
10450 resolve that reference will fail with the same error as the initial attempt.
10451 </description>
10452 <origin>new</origin>
10453 <capabilities>
10454 </capabilities>
10455 <parameters>
10456 <param id="segment">
10457 <inbuf><char/></inbuf>
10458 <description>
10459 The platform-dependent search path segment, encoded as a
10460 <internallink id="mUTF">modified UTF-8</internallink> string.
10461 </description>
10462 </param>
10463 </parameters>
10464 <errors>
10465 <error id="JVMTI_ERROR_ILLEGAL_ARGUMENT">
10466 <paramlink id="segment"/> is an invalid path. In the live phase, anything other than an
10467 existing JAR file is an invalid path.
10468 </error>
10469 </errors>
10470 </function>
10471
10472 <function id="AddToSystemClassLoaderSearch" jkernel="yes" phase="onload" num="151" since="1.1">
10473 <synopsis>Add To System Class Loader Search</synopsis>
10474 <description>
10475 This function can be used to cause instrumentation classes to be
10476 defined by the system class loader. See
10477 <vmspeclink id="ConstantPool.doc.html#79441"
10478 name="Loading Using a User-defined Class Loader"
10479 preposition="in"/>.
10480 After the class loader unsuccessfully searches for a class, the specified platform-dependent search
10481 path <paramlink id="segment"/> will be searched as well. Only one segment may be specified in the
10482 <paramlink id="segment"/>. This function may be called multiple times to add multiple segments, the
10483 segments will be searched in the order that this function was called.
10484 <p/>
10485 In the <code>OnLoad</code> phase the function may be used to specify any platform-dependent
10486 search path segment to be searched after the system class loader unsuccessfully searches
10487 for a class. The segment is typically a directory or JAR file.
10488 <p/>
10489 In the live phase the <paramlink id="segment"/> is a platform-dependent path to a <externallink
10490 id="http://java.sun.com/javase/6/docs/guide/jar/jar.html">JAR file</externallink> to be
10491 searched after the system class loader unsuccessfully searches for a class. The agent should
10492 take care that the JAR file does not contain any classes or resources other than those to be
10493 defined by the system class loader for the purposes of instrumentation.
10494 <p/>
10495 In the live phase the system class loader supports adding a JAR file to be searched if
10496 the system class loader implements a method name <code>appendToClassPathForInstrumentation</code>
10497 which takes a single parameter of type <code>java.lang.String</code>. The method is not required
10498 to have <code>public</code> access.
10499 <p/>
10500 The <vmspeclink/> specifies that a subsequent attempt to resolve a symbolic
10501 reference that the Java virtual machine has previously unsuccessfully attempted
10502 to resolve always fails with the same error that was thrown as a result of the
10503 initial resolution attempt. Consequently, if the JAR file contains an entry
10504 that corresponds to a class for which the Java virtual machine has
10505 unsuccessfully attempted to resolve a reference, then subsequent attempts to
10506 resolve that reference will fail with the same error as the initial attempt.
10507 </description>
10508 <origin>new</origin>
10509 <capabilities>
10510 </capabilities>
10511 <parameters>
10512 <param id="segment">
10513 <inbuf><char/></inbuf>
10514 <description>
10515 The platform-dependent search path segment, encoded as a
10516 <internallink id="mUTF">modified UTF-8</internallink> string.
10517 </description>
10518 </param>
10519 </parameters>
10520 <errors>
10521 <error id="JVMTI_ERROR_ILLEGAL_ARGUMENT">
10522 <paramlink id="segment"/> is an invalid path. In the live phase, anything other than an
10523 existing JAR file is an invalid path.
10524 </error>
10525 <error id="JVMTI_ERROR_CLASS_LOADER_UNSUPPORTED">
10526 Operation not supported by the system class loader.
10527 </error>
10528 </errors>
10529 </function>
10530
10531 </category>
10532
10533
10534 <category id="props" label="System Properties">
10535
10536 <intro>
10537 These functions get and set system properties.
10538 </intro>
10539
10540 <function id="GetSystemProperties" phase="onload" num="130">
10541 <synopsis>Get System Properties</synopsis>
10542 <description>
10543 The list of VM system property keys which may be used with
10544 <functionlink id="GetSystemProperty"/> is returned.
10545 It is strongly recommended that virtual machines provide the
10546 following property keys:
10547 <ul>
10548 <li><code>java.vm.vendor</code></li>
10549 <li><code>java.vm.version</code></li>
10550 <li><code>java.vm.name</code></li>
10551 <li><code>java.vm.info</code></li>
10552 <li><code>java.library.path</code></li>
10553 <li><code>java.class.path</code></li>
10554 </ul>
10555 Provides access to system properties defined by and used
10556 by the VM.
10557 Properties set on the command-line are included.
10558 This allows getting and setting of these properties
10559 before the VM even begins executing bytecodes.
10560 Since this is a VM view of system properties, the set of available
10561 properties will usually be different than that
10562 in <code>java.lang.System.getProperties</code>.
10563 JNI method invocation may be used to access
10564 <code>java.lang.System.getProperties</code>.
10565 <p/>
10566 The set of properties may grow during execution.
10567 </description>
10568 <origin>new</origin>
10569 <capabilities>
10570 </capabilities>
10571 <parameters>
10572 <param id="count_ptr">
10573 <outptr><jint/></outptr>
10574 <description>
10575 On return, points to the number of property keys returned.
10576 </description>
10577 </param>
10578 <param id="property_ptr">
10579 <allocallocbuf outcount="count_ptr"><char/></allocallocbuf>
10580 <description>
10581 On return, points to an array of property keys, encoded as
10582 <internallink id="mUTF">modified UTF-8</internallink> strings.
10583 </description>
10584 </param>
10585 </parameters>
10586 <errors>
10587 </errors>
10588 </function>
10589
10590 <function id="GetSystemProperty" phase="onload" num="131">
10591 <synopsis>Get System Property</synopsis>
10592 <description>
10593 Return a VM system property value given the property key.
10594 <p/>
10595 The function <functionlink id="GetSystemProperties"/>
10596 returns the set of property keys which may be used.
10597 The properties which can be retrieved may grow during
10598 execution.
10599 <p/>
10600 Since this is a VM view of system properties, the values
10601 of properties may differ from that returned by
10602 <code>java.lang.System.getProperty(String)</code>.
10603 A typical VM might copy the values of the VM system
10604 properties into the <code>Properties</code> held by
10605 <code>java.lang.System</code> during the initialization
10606 of that class. Thereafter any changes to the VM system
10607 properties (with <functionlink id="SetSystemProperty"/>)
10608 or the <code>java.lang.System</code> system properties
10609 (with <code>java.lang.System.setProperty(String,String)</code>)
10610 would cause the values to diverge.
10611 JNI method invocation may be used to access
10612 <code>java.lang.System.getProperty(String)</code>.
10613 </description>
10614 <origin>new</origin>
10615 <capabilities>
10616 </capabilities>
10617 <parameters>
10618 <param id="property">
10619 <inbuf><char/></inbuf>
10620 <description>
10621 The key of the property to retrieve, encoded as a
10622 <internallink id="mUTF">modified UTF-8</internallink> string.
10623 </description>
10624 </param>
10625 <param id="value_ptr">
10626 <allocbuf><char/></allocbuf>
10627 <description>
10628 On return, points to the property value, encoded as a
10629 <internallink id="mUTF">modified UTF-8</internallink> string.
10630 </description>
10631 </param>
10632 </parameters>
10633 <errors>
10634 <error id="JVMTI_ERROR_NOT_AVAILABLE">
10635 This property is not available.
10636 Use <functionlink id="GetSystemProperties"/> to find available properties.
10637 </error>
10638 </errors>
10639 </function>
10640
10641 <function id="SetSystemProperty" phase="onloadOnly" num="132">
10642 <synopsis>Set System Property</synopsis>
10643 <description>
10644 Set a VM system property value.
10645 <p/>
10646 The function <functionlink id="GetSystemProperties"/>
10647 returns the set of property keys, some of these may be settable.
10648 See <functionlink id="GetSystemProperty"/>.
10649 </description>
10650 <origin>new</origin>
10651 <capabilities>
10652 </capabilities>
10653 <parameters>
10654 <param id="property">
10655 <inbuf><char/></inbuf>
10656 <description>
10657 The key of the property, encoded as a
10658 <internallink id="mUTF">modified UTF-8</internallink> string.
10659 </description>
10660 </param>
10661 <param id="value">
10662 <inbuf>
10663 <char/>
10664 <nullok>
10665 do not set the value, but return <errorlink id="JVMTI_ERROR_NOT_AVAILABLE"/>
10666 if the property is not writeable
10667 </nullok>
10668 </inbuf>
10669 <description>
10670 The property value to set, encoded as a
10671 <internallink id="mUTF">modified UTF-8</internallink> string.
10672 </description>
10673 </param>
10674 </parameters>
10675 <errors>
10676 <error id="JVMTI_ERROR_NOT_AVAILABLE">
10677 This property is not available or is not writeable.
10678 </error>
10679 </errors>
10680 </function>
10681
10682 </category>
10683
10684 <category id="general" label="General">
10685
10686 <intro>
10687 </intro>
10688
10689 <function id="GetPhase" jkernel="yes" phase="any" num="133">
10690 <synopsis>Get Phase</synopsis>
10691 <description>
10692 Return the current phase of VM execution.
10693 The phases proceed in sequence:
10694 <constants id="jvmtiPhase" label="Phases of execution" kind="enum">
10695 <constant id="JVMTI_PHASE_ONLOAD" num="1">
10696 <code>OnLoad</code> phase: while in the
10697 <internallink id="onload"><code>Agent_OnLoad</code></internallink> function.
10698 </constant>
10699 <constant id="JVMTI_PHASE_PRIMORDIAL" num="2">
10700 Primordial phase: between return from <code>Agent_OnLoad</code> and the
10701 <code>VMStart</code> event.
10702 </constant>
10703 <constant id="JVMTI_PHASE_START" num="6">
10704 Start phase: when the <eventlink id="VMStart"><code>VMStart</code></eventlink> event
10705 is sent and until the <code>VMInit</code> event is sent.
10706 </constant>
10707 <constant id="JVMTI_PHASE_LIVE" num="4">
10708 Live phase: when the <eventlink id="VMInit"><code>VMInit</code></eventlink> event is sent
10709 and until the <eventlink id="VMDeath"></eventlink> event returns.
10710 </constant>
10711 <constant id="JVMTI_PHASE_DEAD" num="8">
10712 Dead phase: after the <eventlink id="VMDeath"></eventlink> event returns or after
10713 start-up failure.
10714 </constant>
10715 </constants>
10716 In the case of start-up failure the VM will proceed directly to the dead
10717 phase skipping intermediate phases and neither a <code>VMInit</code> nor
10718 <code>VMDeath</code> event will be sent.
10719 <p/>
10720 Most <jvmti/> functions operate only in the live phase.
10721 The following functions operate in either the <code>OnLoad</code> or live phases:
10722 <functionphaselist phase="onload"/>
10723 The following functions operate in only the <code>OnLoad</code> phase:
10724 <functionphaselist phase="onloadOnly"/>
10725 The following functions operate in the start or live phases:
10726 <functionphaselist phase="start"/>
10727 The following functions operate in any phase:
10728 <functionphaselist phase="any"/>
10729 JNI functions (except the Invocation API) must only be used in the start or live phases.
10730 <p/>
10731 Most <jvmti/> events are sent only in the live phase.
10732 The following events operate in others phases:
10733 <eventphaselist phase="start"/>
10734 <eventphaselist phase="any"/>
10735 </description>
10736 <origin>new</origin>
10737 <capabilities>
10738 </capabilities>
10739 <parameters>
10740 <param id="phase_ptr">
10741 <outptr><enum>jvmtiPhase</enum></outptr>
10742 <description>
10743 On return, points to the phase.
10744 </description>
10745 </param>
10746 </parameters>
10747 <errors>
10748 </errors>
10749 </function>
10750
10751 <function id="DisposeEnvironment" jkernel="yes" phase="any" num="127">
10752 <synopsis>Dispose Environment</synopsis>
10753 <description>
10754 Shutdown a <jvmti/> connection created with JNI <code>GetEnv</code>
10755 (see <internallink id="environments"><jvmti/> Environments</internallink>).
10756 Dispose of any resources held by the environment.
10757 <issue>
10758 What resources are reclaimed? What is undone?
10759 Breakpoints,watchpoints removed?
10760 </issue>
10761 Threads suspended by this environment are not resumed by this call,
10762 this must be done explicitly by the agent.
10763 Memory allocated by this environment via calls to <jvmti/> functions
10764 is not released, this can be done explicitly by the agent
10765 by calling <functionlink id="Deallocate"/>.
10766 Raw monitors created by this environment are not destroyed,
10767 this can be done explicitly by the agent
10768 by calling <functionlink id="DestroyRawMonitor"/>.
10769 The state of threads waiting on raw monitors created by this environment
10770 are not affected.
10771 <p/>
10772 Any <functionlink id="SetNativeMethodPrefix">native method
10773 prefixes</functionlink> for this environment will be unset;
10774 the agent must remove any prefixed native methods before
10775 dispose is called.
10776 <p/>
10777 Any <internallink id="capability">capabilities</internallink>
10778 held by this environment are relinquished.
10779 <p/>
10780 Events enabled by this environment will no longer be sent, however
10781 event handlers currently running will continue to run. Caution must
10782 be exercised in the design of event handlers whose environment may
10783 be disposed and thus become invalid during their execution.
10784 <p/>
10785 This environment may not be used after this call.
10786 This call returns to the caller.
10787 </description>
10788 <origin>new</origin>
10789 <capabilities>
10790 </capabilities>
10791 <parameters>
10792 </parameters>
10793 <errors>
10794 </errors>
10795 </function>
10796
10797 <function id="SetEnvironmentLocalStorage" jkernel="yes" phase="any" callbacksafe="safe" impl="innative notrace" num="148">
10798 <synopsis>Set Environment Local Storage</synopsis>
10799 <description>
10800 The VM stores a pointer value associated with each environment.
10801 This pointer value is called <i>environment-local storage</i>.
10802 This value is <code>NULL</code> unless set with this function.
10803 Agents can allocate memory in which they store environment specific
10804 information. By setting environment-local storage it can then be
10805 accessed with
10806 <functionlink id="GetEnvironmentLocalStorage"></functionlink>.
10807 <p/>
10808 Called by the agent to set the value of the <jvmti/>
10809 environment-local storage. <jvmti/> supplies to the agent a pointer-size
10810 environment-local storage that can be used to record per-environment
10811 information.
10812 </description>
10813 <origin>new</origin>
10814 <capabilities>
10815 </capabilities>
10816 <parameters>
10817 <param id="data">
10818 <inbuf>
10819 <void/>
10820 <nullok>value is set to <code>NULL</code></nullok>
10821 </inbuf>
10822 <description>
10823 The value to be entered into the environment-local storage.
10824 </description>
10825 </param>
10826 </parameters>
10827 <errors>
10828 </errors>
10829 </function>
10830
10831 <function id="GetEnvironmentLocalStorage" jkernel="yes" phase="any" callbacksafe="safe" impl="innative notrace" num="147">
10832 <synopsis>Get Environment Local Storage</synopsis>
10833 <description>
10834 Called by the agent to get the value of the <jvmti/> environment-local
10835 storage.
10836 </description>
10837 <origin>new</origin>
10838 <capabilities>
10839 </capabilities>
10840 <parameters>
10841 <param id="data_ptr">
10842 <agentbuf><void/></agentbuf>
10843 <description>
10844 Pointer through which the value of the environment local
10845 storage is returned.
10846 If environment-local storage has not been set with
10847 <functionlink id="SetEnvironmentLocalStorage"></functionlink> returned
10848 pointer is <code>NULL</code>.
10849 </description>
10850 </param>
10851 </parameters>
10852 <errors>
10853 </errors>
10854 </function>
10855
10856 <function id="GetVersionNumber" jkernel="yes" phase="any" num="88">
10857 <synopsis>Get Version Number</synopsis>
10858 <description>
10859 Return the <jvmti/> version via <code>version_ptr</code>.
10860 The return value is the version identifier.
10861 The version identifier includes major, minor and micro
10862 version as well as the interface type.
10863 <constants id="jvmtiVersionInterfaceTypes" label="Version Interface Types" kind="bits">
10864 <constant id="JVMTI_VERSION_INTERFACE_JNI" num="0x00000000">
10865 Value of <code>JVMTI_VERSION_MASK_INTERFACE_TYPE</code> for JNI.
10866 </constant>
10867 <constant id="JVMTI_VERSION_INTERFACE_JVMTI" num="0x30000000">
10868 Value of <code>JVMTI_VERSION_MASK_INTERFACE_TYPE</code> for <jvmti/>.
10869 </constant>
10870 </constants>
10871 <constants id="jvmtiVersionMasks" label="Version Masks" kind="bits">
10872 <constant id="JVMTI_VERSION_MASK_INTERFACE_TYPE" num="0x70000000">
10873 Mask to extract interface type.
10874 The value of the version returned by this function masked with
10875 <code>JVMTI_VERSION_MASK_INTERFACE_TYPE</code> is always
10876 <code>JVMTI_VERSION_INTERFACE_JVMTI</code>
10877 since this is a <jvmti/> function.
10878 </constant>
10879 <constant id="JVMTI_VERSION_MASK_MAJOR" num="0x0FFF0000">
10880 Mask to extract major version number.
10881 </constant>
10882 <constant id="JVMTI_VERSION_MASK_MINOR" num="0x0000FF00">
10883 Mask to extract minor version number.
10884 </constant>
10885 <constant id="JVMTI_VERSION_MASK_MICRO" num="0x000000FF">
10886 Mask to extract micro version number.
10887 </constant>
10888 </constants>
10889 <constants id="jvmtiVersionShifts" label="Version Shifts" kind="bits">
10890 <constant id="JVMTI_VERSION_SHIFT_MAJOR" num="16">
10891 Shift to extract major version number.
10892 </constant>
10893 <constant id="JVMTI_VERSION_SHIFT_MINOR" num="8">
10894 Shift to extract minor version number.
10895 </constant>
10896 <constant id="JVMTI_VERSION_SHIFT_MICRO" num="0">
10897 Shift to extract micro version number.
10898 </constant>
10899 </constants>
10900 </description>
10901 <origin>jvmdi</origin>
10902 <capabilities>
10903 </capabilities>
10904 <parameters>
10905 <param id="version_ptr">
10906 <outptr><jint/></outptr>
10907 <description>
10908 On return, points to the <jvmti/> version.
10909 </description>
10910 </param>
10911 </parameters>
10912 <errors>
10913 </errors>
10914 </function>
10915
10916
10917 <function id="GetErrorName" phase="any" num="128">
10918 <synopsis>Get Error Name</synopsis>
10919 <description>
10920 Return the symbolic name for an
10921 <internallink id="ErrorSection">error code</internallink>.
10922 <p/>
10923 For example
10924 <code>GetErrorName(env, JVMTI_ERROR_NONE, &amp;err_name)</code>
10925 would return in <code>err_name</code> the string
10926 <code>"JVMTI_ERROR_NONE"</code>.
10927 </description>
10928 <origin>new</origin>
10929 <capabilities>
10930 </capabilities>
10931 <parameters>
10932 <param id="error">
10933 <enum>jvmtiError</enum>
10934 <description>
10935 The error code.
10936 </description>
10937 </param>
10938 <param id="name_ptr">
10939 <allocbuf><char/></allocbuf>
10940 <description>
10941 On return, points to the error name.
10942 The name is encoded as a
10943 <internallink id="mUTF">modified UTF-8</internallink> string,
10944 but is restricted to the ASCII subset.
10945 </description>
10946 </param>
10947 </parameters>
10948 <errors>
10949 </errors>
10950 </function>
10951
10952 <function id="SetVerboseFlag" phase="any" num="150">
10953 <synopsis>Set Verbose Flag</synopsis>
10954 <description>
10955 <constants id="jvmtiVerboseFlag" label="Verbose Flag Enumeration" kind="enum">
10956 <constant id="JVMTI_VERBOSE_OTHER" num="0">
10957 Verbose output other than the below.
10958 </constant>
10959 <constant id="JVMTI_VERBOSE_GC" num="1">
10960 Verbose garbage collector output, like that specified with <code>-verbose:gc</code>.
10961 </constant>
10962 <constant id="JVMTI_VERBOSE_CLASS" num="2">
10963 Verbose class loading output, like that specified with <code>-verbose:class</code>.
10964 </constant>
10965 <constant id="JVMTI_VERBOSE_JNI" num="4">
10966 Verbose JNI output, like that specified with <code>-verbose:jni</code>.
10967 </constant>
10968 </constants>
10969 Control verbose output.
10970 This is the output which typically is sent to <code>stderr</code>.
10971 </description>
10972 <origin>new</origin>
10973 <capabilities>
10974 </capabilities>
10975 <parameters>
10976 <param id="flag">
10977 <enum>jvmtiVerboseFlag</enum>
10978 <description>
10979 Which verbose flag to set.
10980 </description>
10981 </param>
10982 <param id="value">
10983 <jboolean/>
10984 <description>
10985 New value of the flag.
10986 </description>
10987 </param>
10988 </parameters>
10989 <errors>
10990 </errors>
10991 </function>
10992
10993
10994 <function id="GetJLocationFormat" phase="any" num="129">
10995 <synopsis>Get JLocation Format</synopsis>
10996 <description>
10997 Although the greatest functionality is achieved with location information
10998 referencing the virtual machine bytecode index, the definition of
10999 <code>jlocation</code> has intentionally been left unconstrained to allow VM
11000 implementations that do not have this information.
11001 <p/>
11002 This function describes the representation of <code>jlocation</code> used in this VM.
11003 If the returned format is <datalink id="JVMTI_JLOCATION_JVMBCI"></datalink>,
11004 <code>jlocation</code>s can
11005 be used as in indices into the array returned by
11006 <functionlink id="GetBytecodes"></functionlink>.
11007 <constants id="jvmtiJlocationFormat" label="JLocation Format Enumeration" kind="enum">
11008 <constant id="JVMTI_JLOCATION_JVMBCI" num="1">
11009 <code>jlocation</code> values represent virtual machine
11010 bytecode indices--that is, offsets into the
11011 virtual machine code for a method.
11012 </constant>
11013 <constant id="JVMTI_JLOCATION_MACHINEPC" num="2">
11014 <code>jlocation</code> values represent native machine
11015 program counter values.
11016 </constant>
11017 <constant id="JVMTI_JLOCATION_OTHER" num="0">
11018 <code>jlocation</code> values have some other representation.
11019 </constant>
11020 </constants>
11021 </description>
11022 <origin>new</origin>
11023 <capabilities>
11024 </capabilities>
11025 <parameters>
11026 <param id="format_ptr">
11027 <outptr><enum>jvmtiJlocationFormat</enum></outptr>
11028 <description>
11029 On return, points to the format identifier for <code>jlocation</code> values.
11030 </description>
11031 </param>
11032 </parameters>
11033 <errors>
11034 </errors>
11035 </function>
11036
11037 </category>
11038
11039 </functionsection>
11040
11041 <errorsection label="Error Reference">
11042 <intro>
11043 Every <jvmti/> function returns a <b><code>jvmtiError</code></b> error code.
11044 <p/>
11045 It is the responsibility of the agent to call <jvmti/> functions with
11046 valid parameters and in the proper context (calling thread is attached,
11047 phase is correct, etc.).
11048 Detecting some error conditions may be difficult, inefficient, or
11049 impossible for an implementation.
11050 The errors listed in
11051 <internallink id="reqerrors">Function Specific Required Errors</internallink>
11052 must be detected by the implementation.
11053 All other errors represent the recommended response to the error
11054 condition.
11055 </intro>
11056
11057 <errorcategory id="universal-error" label="Universal Errors">
11058 <intro>
11059 The following errors may be returned by any function
11060 </intro>
11061
11062 <errorid id="JVMTI_ERROR_NONE" num="0">
11063 No error has occurred. This is the error code that is returned
11064 on successful completion of the function.
11065 </errorid>
11066 <errorid id="JVMTI_ERROR_NULL_POINTER" num="100">
11067 Pointer is unexpectedly <code>NULL</code>.
11068 </errorid>
11069 <errorid id="JVMTI_ERROR_OUT_OF_MEMORY" num="110">
11070 The function attempted to allocate memory and no more memory was
11071 available for allocation.
11072 </errorid>
11073 <errorid id="JVMTI_ERROR_ACCESS_DENIED" num="111">
11074 The desired functionality has not been enabled in this virtual machine.
11075 </errorid>
11076 <errorid id="JVMTI_ERROR_UNATTACHED_THREAD" num="115">
11077 The thread being used to call this function is not attached
11078 to the virtual machine. Calls must be made from attached threads.
11079 See <code>AttachCurrentThread</code> in the JNI invocation API.
11080 </errorid>
11081 <errorid id="JVMTI_ERROR_INVALID_ENVIRONMENT" num="116">
11082 The <jvmti/> environment provided is no longer connected or is
11083 not an environment.
11084 </errorid>
11085 <errorid id="JVMTI_ERROR_WRONG_PHASE" num="112">
11086 The desired functionality is not available in the current
11087 <functionlink id="GetPhase">phase</functionlink>.
11088 Always returned if the virtual machine has completed running.
11089 </errorid>
11090 <errorid id="JVMTI_ERROR_INTERNAL" num="113">
11091 An unexpected internal error has occurred.
11092 </errorid>
11093 </errorcategory>
11094
11095 <errorcategory id="reqerrors" label="Function Specific Required Errors">
11096 <intro>
11097 The following errors are returned by some <jvmti/> functions and must
11098 be returned by the implementation when the condition occurs.
11099 </intro>
11100
11101 <errorid id="JVMTI_ERROR_INVALID_PRIORITY" num="12">
11102 Invalid priority.
11103 </errorid>
11104 <errorid id="JVMTI_ERROR_THREAD_NOT_SUSPENDED" num="13">
11105 Thread was not suspended.
11106 </errorid>
11107 <errorid id="JVMTI_ERROR_THREAD_SUSPENDED" num="14">
11108 Thread already suspended.
11109 </errorid>
11110 <errorid id="JVMTI_ERROR_THREAD_NOT_ALIVE" num="15">
11111 This operation requires the thread to be alive--that is,
11112 it must be started and not yet have died.
11113 </errorid>
11114 <errorid id="JVMTI_ERROR_CLASS_NOT_PREPARED" num="22">
11115 The class has been loaded but not yet prepared.
11116 </errorid>
11117 <errorid id="JVMTI_ERROR_NO_MORE_FRAMES" num="31">
11118 There are no Java programming language or JNI stack frames at the specified depth.
11119 </errorid>
11120 <errorid id="JVMTI_ERROR_OPAQUE_FRAME" num="32">
11121 Information about the frame is not available (e.g. for native frames).
11122 </errorid>
11123 <errorid id="JVMTI_ERROR_DUPLICATE" num="40">
11124 Item already set.
11125 </errorid>
11126 <errorid id="JVMTI_ERROR_NOT_FOUND" num="41">
11127 Desired element (e.g. field or breakpoint) not found
11128 </errorid>
11129 <errorid id="JVMTI_ERROR_NOT_MONITOR_OWNER" num="51">
11130 This thread doesn't own the raw monitor.
11131 </errorid>
11132 <errorid id="JVMTI_ERROR_INTERRUPT" num="52">
11133 The call has been interrupted before completion.
11134 </errorid>
11135 <errorid id="JVMTI_ERROR_UNMODIFIABLE_CLASS" num="79">
11136 The class cannot be modified.
11137 </errorid>
11138 <errorid id="JVMTI_ERROR_NOT_AVAILABLE" num="98">
11139 The functionality is not available in this virtual machine.
11140 </errorid>
11141 <errorid id="JVMTI_ERROR_ABSENT_INFORMATION" num="101">
11142 The requested information is not available.
11143 </errorid>
11144 <errorid id="JVMTI_ERROR_INVALID_EVENT_TYPE" num="102">
11145 The specified event type ID is not recognized.
11146 </errorid>
11147 <errorid id="JVMTI_ERROR_NATIVE_METHOD" num="104">
11148 The requested information is not available for native method.
11149 </errorid>
11150 <errorid id="JVMTI_ERROR_CLASS_LOADER_UNSUPPORTED" num="106">
11151 The class loader does not support this operation.
11152 </errorid>
11153 </errorcategory>
11154
11155 <errorcategory id="function-specific-errors" label="Function Specific Agent Errors">
11156 <intro>
11157 The following errors are returned by some <jvmti/> functions.
11158 They are returned in the event of invalid parameters passed by the
11159 agent or usage in an invalid context.
11160 An implementation is not required to detect these errors.
11161 </intro>
11162
11163 <errorid id="JVMTI_ERROR_INVALID_THREAD" num="10">
11164 The passed thread is not a valid thread.
11165 </errorid>
11166 <errorid id="JVMTI_ERROR_INVALID_FIELDID" num="25">
11167 Invalid field.
11168 </errorid>
11169 <errorid id="JVMTI_ERROR_INVALID_METHODID" num="23">
11170 Invalid method.
11171 </errorid>
11172 <errorid id="JVMTI_ERROR_INVALID_LOCATION" num="24">
11173 Invalid location.
11174 </errorid>
11175 <errorid id="JVMTI_ERROR_INVALID_OBJECT" num="20">
11176 Invalid object.
11177 </errorid>
11178 <errorid id="JVMTI_ERROR_INVALID_CLASS" num="21">
11179 Invalid class.
11180 </errorid>
11181 <errorid id="JVMTI_ERROR_TYPE_MISMATCH" num="34">
11182 The variable is not an appropriate type for the function used.
11183 </errorid>
11184 <errorid id="JVMTI_ERROR_INVALID_SLOT" num="35">
11185 Invalid slot.
11186 </errorid>
11187 <errorid id="JVMTI_ERROR_MUST_POSSESS_CAPABILITY" num="99">
11188 The capability being used is false in this environment.
11189 </errorid>
11190 <errorid id="JVMTI_ERROR_INVALID_THREAD_GROUP" num="11">
11191 Thread group invalid.
11192 </errorid>
11193 <errorid id="JVMTI_ERROR_INVALID_MONITOR" num="50">
11194 Invalid raw monitor.
11195 </errorid>
11196 <errorid id="JVMTI_ERROR_ILLEGAL_ARGUMENT" num="103">
11197 Illegal argument.
11198 </errorid>
11199 <errorid id="JVMTI_ERROR_INVALID_TYPESTATE" num="65">
11200 The state of the thread has been modified, and is now inconsistent.
11201 </errorid>
11202 <errorid id="JVMTI_ERROR_UNSUPPORTED_VERSION" num="68">
11203 A new class file has a version number not supported by this VM.
11204 </errorid>
11205 <errorid id="JVMTI_ERROR_INVALID_CLASS_FORMAT" num="60">
11206 A new class file is malformed (the VM would return a <code>ClassFormatError</code>).
11207 </errorid>
11208 <errorid id="JVMTI_ERROR_CIRCULAR_CLASS_DEFINITION" num="61">
11209 The new class file definitions would lead to a circular
11210 definition (the VM would return a <code>ClassCircularityError</code>).
11211 </errorid>
11212 <errorid id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_ADDED" num="63">
11213 A new class file would require adding a method.
11214 </errorid>
11215 <errorid id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_SCHEMA_CHANGED" num="64">
11216 A new class version changes a field.
11217 </errorid>
11218 <errorid id="JVMTI_ERROR_FAILS_VERIFICATION" num="62">
11219 The class bytes fail verification.
11220 </errorid>
11221 <errorid id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_HIERARCHY_CHANGED" num="66">
11222 A direct superclass is different for the new class
11223 version, or the set of directly implemented
11224 interfaces is different.
11225 </errorid>
11226 <errorid id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_DELETED" num="67">
11227 A new class version does not declare a method
11228 declared in the old class version.
11229 </errorid>
11230 <errorid id="JVMTI_ERROR_NAMES_DONT_MATCH" num="69">
11231 The class name defined in the new class file is
11232 different from the name in the old class object.
11233 </errorid>
11234 <errorid id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_CLASS_MODIFIERS_CHANGED" num="70">
11235 A new class version has different modifiers.
11236 </errorid>
11237 <errorid id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_MODIFIERS_CHANGED" num="71">
11238 A method in the new class version has different modifiers
11239 than its counterpart in the old class version.
11240 </errorid>
11241 </errorcategory>
11242 </errorsection>
11243
11244 <eventsection label="Events">
11245 <intro label="Handling Events" id="eventIntro">
11246 Agents can be informed of many events that occur in application
11247 programs.
11248 <p/>
11249 To handle events, designate a set of callback functions with
11250 <functionlink id="SetEventCallbacks"></functionlink>.
11251 For each event the corresponding callback function will be
11252 called.
11253 Arguments to the callback function provide additional
11254 information about the event.
11255 <p/>
11256 The callback function is usually called from within an application
11257 thread. The <jvmti/> implementation does not
11258 queue events in any way. This means
11259 that event callback functions must be written
11260 carefully. Here are some general guidelines. See
11261 the individual event descriptions for further
11262 suggestions.
11263 <p/>
11264 <ul>
11265 <li>Any exception thrown during the execution of an event callback can
11266 overwrite any current pending exception in the current application thread.
11267 Care must be taken to preserve a pending exception
11268 when an event callback makes a JNI call that might generate an exception.
11269 </li>
11270 <li>Event callback functions must be re-entrant. The <jvmti/> implementation does
11271 not queue events. If an agent needs to process events one at a time, it
11272 can use a raw monitor inside the
11273 event callback functions to serialize event processing.
11274 </li>
11275 <li>Event callback functions that execute JNI's FindClass function to load
11276 classes need to note that FindClass locates the class loader associated
11277 with the current native method. For the purposes of class loading, an
11278 event callback that includes a JNI environment as a parameter to the
11279 callback will treated as if it is a native call, where the native method
11280 is in the class of the event thread's current frame.
11281 </li>
11282 </ul>
11283 <p/>
11284 Some <jvmti/> events identify objects with JNI references.
11285 All references
11286 in <jvmti/> events are JNI local references and will become invalid
11287 after the event callback returns.
11288 Unless stated otherwise, memory referenced by pointers sent in event
11289 callbacks may not be referenced after the event callback returns.
11290 <p/>
11291 Except where stated otherwise, events are delivered on the thread
11292 that caused the event.
11293 Events are sent at the time they occur.
11294 The specification for each event includes the set of
11295 <functionlink id="GetPhase">phases</functionlink> in which it can be sent;
11296 if an event triggering activity occurs during another phase, no event
11297 is sent.
11298 <p/>
11299 A thread that generates an event does not change its execution status
11300 (for example, the event does not cause the thread to be suspended).
11301 If an agent wishes the event to result in suspension, then the agent
11302 is responsible for explicitly suspending the thread with
11303 <functionlink id="SuspendThread"></functionlink>.
11304 <p/>
11305 If an event is enabled in multiple environments, the event will be sent
11306 to each agent in the order that the environments were created.
11307 </intro>
11308
11309 <intro label="Enabling Events" id="enablingevents">
11310 All events are initially disabled. In order to receive any
11311 event:
11312 <ul>
11313 <li>
11314 If the event requires a capability, that capability must
11315 be added with
11316 <functionlink id="AddCapabilities"></functionlink>.
11317 </li>
11318 <li>
11319 A callback for the event must be set with
11320 <functionlink id="SetEventCallbacks"></functionlink>.
11321 </li>
11322 <li>
11323 The event must be enabled with
11324 <functionlink id="SetEventNotificationMode"></functionlink>.
11325 </li>
11326 </ul>
11327 </intro>
11328
11329 <intro label="Multiple Co-located Events" id="eventorder">
11330 In many situations it is possible for multiple events to occur
11331 at the same location in one thread. When this happens, all the events
11332 are reported through the event callbacks in the order specified in this section.
11333 <p/>
11334 If the current location is at the entry point of a method, the
11335 <eventlink id="MethodEntry"></eventlink> event is reported before
11336 any other event at the current location in the same thread.
11337 <p/>
11338 If an exception catch has been detected at the current location,
11339 either because it is the beginning of a catch clause or a native method
11340 that cleared a pending exception has returned, the
11341 <code>exceptionCatch</code> event is reported before
11342 any other event at the current location in the same thread.
11343 <p/>
11344 If a <code>singleStep</code> event or
11345 <code>breakpoint</code> event is triggered at the
11346 current location, the event is defined to occur
11347 immediately before the code at the current location is executed.
11348 These events are reported before any events which are triggered
11349 by the execution of code at the current location in the same
11350 thread (specifically:
11351 <code>exception</code>,
11352 <code>fieldAccess</code>, and
11353 <code>fieldModification</code>).
11354 If both a step and breakpoint event are triggered for the same thread and
11355 location, the step event is reported before the breakpoint event.
11356 <p/>
11357 If the current location is the exit point of a method (that is, the last
11358 location before returning to the caller), the
11359 <eventlink id="MethodExit"></eventlink> event and
11360 the <eventlink id="FramePop"></eventlink> event (if requested)
11361 are reported after all other events at the current location in the same
11362 thread. There is no specified ordering of these two events
11363 with respect to each other.
11364 <p/>
11365 Co-located events can be triggered during the processing of some other
11366 event by the agent at the same location in the same thread.
11367 If such an event, of type <i>y</i>, is triggered during the processing of
11368 an event of type <i>x</i>, and if <i>x</i>
11369 precedes <i>y</i> in the ordering specified above, the co-located event
11370 <i>y</i> is reported for the current thread and location. If <i>x</i> does not precede
11371 <i>y</i>, <i>y</i> is not reported for the current thread and location.
11372 For example, if a breakpoint is set at the current location
11373 during the processing of <eventlink id="SingleStep"></eventlink>,
11374 that breakpoint will be reported before the thread moves off the current
11375 location.
11376 <p/>The following events are never considered to be co-located with
11377 other events.
11378 <ul>
11379 <li><eventlink id="VMStart"></eventlink></li>
11380 <li><eventlink id="VMInit"></eventlink></li>
11381 <li><eventlink id="VMDeath"></eventlink></li>
11382 <li><eventlink id="ThreadStart"></eventlink></li>
11383 <li><eventlink id="ThreadEnd"></eventlink></li>
11384 <li><eventlink id="ClassLoad"></eventlink></li>
11385 <li><eventlink id="ClassPrepare"></eventlink></li>
11386 </ul>
11387 </intro>
11388
11389 <intro label="Event Callbacks" id="jvmtiEventCallbacks">
11390 The event callback structure below is used to specify the handler function
11391 for events. It is set with the
11392 <functionlink id="SetEventCallbacks"></functionlink> function.
11393 </intro>
11394
11395 <event label="Single Step"
11396 id="SingleStep" const="JVMTI_EVENT_SINGLE_STEP" filtered="thread" num="60">
11397 <description>
11398 Single step events allow the agent to trace thread execution
11399 at the finest granularity allowed by the VM. A single step event is
11400 generated whenever a thread reaches a new location.
11401 Typically, single step events represent the completion of one VM
11402 instruction as defined in the <vmspeclink/>. However, some implementations
11403 may define locations differently. In any case the
11404 <code>method</code> and <code>location</code>
11405 parameters uniquely identify the current location and allow
11406 the mapping to source file and line number when that information is
11407 available.
11408 <p/>
11409 No single step events are generated from within native methods.
11410 </description>
11411 <origin>jvmdi</origin>
11412 <capabilities>
11413 <required id="can_generate_single_step_events"></required>
11414 </capabilities>
11415 <parameters>
11416 <param id="jni_env">
11417 <outptr>
11418 <struct>JNIEnv</struct>
11419 </outptr>
11420 <description>
11421 The JNI environment of the event (current) thread
11422 </description>
11423 </param>
11424 <param id="thread">
11425 <jthread/>
11426 <description>
11427 Thread about to execution a new instruction
11428 </description>
11429 </param>
11430 <param id="klass">
11431 <jclass method="method"/>
11432 <description>
11433 Class of the method about to execute a new instruction
11434 </description>
11435 </param>
11436 <param id="method">
11437 <jmethodID class="klass"/>
11438 <description>
11439 Method about to execute a new instruction
11440 </description>
11441 </param>
11442 <param id="location">
11443 <jlocation/>
11444 <description>
11445 Location of the new instruction
11446 </description>
11447 </param>
11448 </parameters>
11449 </event>
11450
11451 <event label="Breakpoint"
11452 id="Breakpoint" const="JVMTI_EVENT_BREAKPOINT" filtered="thread" num="62">
11453 <description>
11454 Breakpoint events are generated whenever a thread reaches a location
11455 designated as a breakpoint with <functionlink id="SetBreakpoint"></functionlink>.
11456 The <code>method</code> and <code>location</code>
11457 parameters uniquely identify the current location and allow
11458 the mapping to source file and line number when that information is
11459 available.
11460 </description>
11461 <origin>jvmdi</origin>
11462 <capabilities>
11463 <required id="can_generate_breakpoint_events"></required>
11464 </capabilities>
11465 <parameters>
11466 <param id="jni_env">
11467 <outptr>
11468 <struct>JNIEnv</struct>
11469 </outptr>
11470 <description>
11471 The JNI environment of the event (current) thread.
11472 </description>
11473 </param>
11474 <param id="thread">
11475 <jthread/>
11476 <description>
11477 Thread that hit the breakpoint
11478 </description>
11479 </param>
11480 <param id="klass">
11481 <jclass method="method"/>
11482 <description>
11483 Class of the method that hit the breakpoint
11484 </description>
11485 </param>
11486 <param id="method">
11487 <jmethodID class="klass"/>
11488 <description>
11489 Method that hit the breakpoint
11490 </description>
11491 </param>
11492 <param id="location">
11493 <jlocation/>
11494 <description>
11495 location of the breakpoint
11496 </description>
11497 </param>
11498 </parameters>
11499 </event>
11500
11501 <event label="Field Access"
11502 id="FieldAccess" const="JVMTI_EVENT_FIELD_ACCESS" filtered="thread" num="63">
11503 <description>
11504 Field access events are generated whenever a thread accesses
11505 a field that was designated as a watchpoint
11506 with <functionlink id="SetFieldAccessWatch"></functionlink>.
11507 The <code>method</code> and <code>location</code>
11508 parameters uniquely identify the current location and allow
11509 the mapping to source file and line number when that information is
11510 available.
11511 </description>
11512 <origin>jvmdi</origin>
11513 <capabilities>
11514 <required id="can_generate_field_access_events"></required>
11515 </capabilities>
11516 <parameters>
11517 <param id="jni_env">
11518 <outptr>
11519 <struct>JNIEnv</struct>
11520 </outptr>
11521 <description>
11522 The JNI environment of the event (current) thread
11523 </description>
11524 </param>
11525 <param id="thread">
11526 <jthread/>
11527 <description>
11528 Thread accessing the field
11529 </description>
11530 </param>
11531 <param id="klass">
11532 <jclass method="method"/>
11533 <description>
11534 Class of the method where the access is occurring
11535 </description>
11536 </param>
11537 <param id="method">
11538 <jmethodID class="klass"/>
11539 <description>
11540 Method where the access is occurring
11541 </description>
11542 </param>
11543 <param id="location">
11544 <jlocation/>
11545 <description>
11546 Location where the access is occurring
11547 </description>
11548 </param>
11549 <param id="field_klass">
11550 <jclass field="field"/>
11551 <description>
11552 Class of the field being accessed
11553 </description>
11554 </param>
11555 <param id="object">
11556 <jobject/>
11557 <description>
11558 Object with the field being accessed if the field is an
11559 instance field; <code>NULL</code> otherwise
11560 </description>
11561 </param>
11562 <param id="field">
11563 <jfieldID class="field_klass"/>
11564 <description>
11565 Field being accessed
11566 </description>
11567 </param>
11568 </parameters>
11569 </event>
11570
11571 <event label="Field Modification"
11572 id="FieldModification" const="JVMTI_EVENT_FIELD_MODIFICATION" filtered="thread" num="64">
11573 <description>
11574 Field modification events are generated whenever a thread modifies
11575 a field that was designated as a watchpoint
11576 with <functionlink id="SetFieldModificationWatch"></functionlink>.
11577 The <code>method</code> and <code>location</code>
11578 parameters uniquely identify the current location and allow
11579 the mapping to source file and line number when that information is
11580 available.
11581 </description>
11582 <origin>jvmdi</origin>
11583 <capabilities>
11584 <required id="can_generate_field_modification_events"></required>
11585 </capabilities>
11586 <parameters>
11587 <param id="jni_env">
11588 <outptr>
11589 <struct>JNIEnv</struct>
11590 </outptr>
11591 <description>
11592 The JNI environment of the event (current) thread
11593 </description>
11594 </param>
11595 <param id="thread">
11596 <jthread/>
11597 <description>
11598 Thread modifying the field
11599 </description>
11600 </param>
11601 <param id="klass">
11602 <jclass method="method"/>
11603 <description>
11604 Class of the method where the modification is occurring
11605 </description>
11606 </param>
11607 <param id="method">
11608 <jmethodID class="klass"/>
11609 <description>
11610 Method where the modification is occurring
11611 </description>
11612 </param>
11613 <param id="location">
11614 <jlocation/>
11615 <description>
11616 Location where the modification is occurring
11617 </description>
11618 </param>
11619 <param id="field_klass">
11620 <jclass field="field"/>
11621 <description>
11622 Class of the field being modified
11623 </description>
11624 </param>
11625 <param id="object">
11626 <jobject/>
11627 <description>
11628 Object with the field being modified if the field is an
11629 instance field; <code>NULL</code> otherwise
11630 </description>
11631 </param>
11632 <param id="field">
11633 <jfieldID class="field_klass"/>
11634 <description>
11635 Field being modified
11636 </description>
11637 </param>
11638 <param id="signature_type">
11639 <char/>
11640 <description>
11641 Signature type of the new value
11642 </description>
11643 </param>
11644 <param id="new_value">
11645 <jvalue/>
11646 <description>
11647 The new value
11648 </description>
11649 </param>
11650 </parameters>
11651 </event>
11652
11653 <event label="Frame Pop"
11654 id="FramePop" const="JVMTI_EVENT_FRAME_POP" filtered="thread" num="61">
11655 <description>
11656 Frame pop events are generated upon exit from a single method
11657 in a single frame as specified
11658 in a call to <functionlink id="NotifyFramePop"></functionlink>.
11659 This is true whether termination is caused by
11660 executing its return instruction
11661 or by throwing an exception to its caller
11662 (see <paramlink id="was_popped_by_exception"></paramlink>).
11663 However, frame pops caused by the <functionlink id="PopFrame"/>
11664 function are not reported.
11665 <p/>
11666 The location reported by <functionlink id="GetFrameLocation"></functionlink>
11667 identifies the executable location in the returning method,
11668 immediately prior to the return.
11669 </description>
11670 <origin>jvmdi</origin>
11671 <capabilities>
11672 <required id="can_generate_frame_pop_events"></required>
11673 </capabilities>
11674 <parameters>
11675 <param id="jni_env">
11676 <outptr>
11677 <struct>JNIEnv</struct>
11678 </outptr>
11679 <description>
11680 The JNI environment of the event (current) thread
11681 </description>
11682 </param>
11683 <param id="thread">
11684 <jthread/>
11685 <description>
11686 Thread that is popping the frame
11687 </description>
11688 </param>
11689 <param id="klass">
11690 <jclass method="method"/>
11691 <description>
11692 Class of the method being popped
11693 </description>
11694 </param>
11695 <param id="method">
11696 <jmethodID class="klass"/>
11697 <description>
11698 Method being popped
11699 </description>
11700 </param>
11701 <param id="was_popped_by_exception">
11702 <jboolean/>
11703 <description>
11704 True if frame was popped by a thrown exception.
11705 False if method exited through its return instruction.
11706 </description>
11707 </param>
11708 </parameters>
11709 </event>
11710
11711 <event label="Method Entry"
11712 id="MethodEntry" const="JVMTI_EVENT_METHOD_ENTRY" filtered="thread" num="65">
11713 <description>
11714 Method entry events are generated upon entry of Java
11715 programming language methods (including native methods).
11716 <p/>
11717 The location reported by <functionlink id="GetFrameLocation"></functionlink>
11718 identifies the initial executable location in
11719 the method.
11720 <p/>
11721 Enabling method
11722 entry or exit events will significantly degrade performance on many platforms and is thus
11723 not advised for performance critical usage (such as profiling).
11724 <internallink id="bci">Bytecode instrumentation</internallink> should be
11725 used in these cases.
11726 </description>
11727 <origin>jvmdi</origin>
11728 <capabilities>
11729 <required id="can_generate_method_entry_events"></required>
11730 </capabilities>
11731 <parameters>
11732 <param id="jni_env">
11733 <outptr>
11734 <struct>JNIEnv</struct>
11735 </outptr>
11736 <description>
11737 The JNI environment of the event (current) thread
11738 </description>
11739 </param>
11740 <param id="thread">
11741 <jthread/>
11742 <description>
11743 Thread entering the method
11744 </description>
11745 </param>
11746 <param id="klass">
11747 <jclass method="method"/>
11748 <description>
11749 Class of the method being entered
11750 </description>
11751 </param>
11752 <param id="method">
11753 <jmethodID class="klass"/>
11754 <description>
11755 Method being entered
11756 </description>
11757 </param>
11758 </parameters>
11759 </event>
11760
11761 <event label="Method Exit"
11762 id="MethodExit" const="JVMTI_EVENT_METHOD_EXIT" filtered="thread" num="66">
11763 <description>
11764 Method exit events are generated upon exit from Java
11765 programming language methods (including native methods).
11766 This is true whether termination is caused by
11767 executing its return instruction
11768 or by throwing an exception to its caller
11769 (see <paramlink id="was_popped_by_exception"></paramlink>).
11770 <p/>
11771 The <code>method</code> field uniquely identifies the
11772 method being entered or exited. The <code>frame</code> field provides
11773 access to the stack frame for the method.
11774 <p/>
11775 The location reported by <functionlink id="GetFrameLocation"></functionlink>
11776 identifies the executable location in the returning method
11777 immediately prior to the return.
11778 <p/>
11779 Enabling method
11780 entry or exit events will significantly degrade performance on many platforms and is thus
11781 not advised for performance critical usage (such as profiling).
11782 <internallink id="bci">Bytecode instrumentation</internallink> should be
11783 used in these cases.
11784 </description>
11785 <origin>jvmdi</origin>
11786 <capabilities>
11787 <required id="can_generate_method_exit_events"></required>
11788 </capabilities>
11789 <parameters>
11790 <param id="jni_env">
11791 <outptr>
11792 <struct>JNIEnv</struct>
11793 </outptr>
11794 <description>
11795 The JNI environment of the event (current) thread
11796 </description>
11797 </param>
11798 <param id="thread">
11799 <jthread/>
11800 <description>
11801 Thread exiting the method
11802 </description>
11803 </param>
11804 <param id="klass">
11805 <jclass method="method"/>
11806 <description>
11807 Class of the method being exited
11808 </description>
11809 </param>
11810 <param id="method">
11811 <jmethodID class="klass"/>
11812 <description>
11813 Method being exited
11814 </description>
11815 </param>
11816 <param id="was_popped_by_exception">
11817 <jboolean/>
11818 <description>
11819 True if frame was popped by a thrown exception.
11820 False if method exited through its return instruction.
11821 </description>
11822 </param>
11823 <param id="return_value">
11824 <jvalue/>
11825 <description>
11826 The return value of the method being exited.
11827 Undefined and should not be used if
11828 <paramlink id="was_popped_by_exception"></paramlink>
11829 is true.
11830 </description>
11831 </param>
11832 </parameters>
11833 </event>
11834
11835 <event label="Native Method Bind" phase="any"
11836 id="NativeMethodBind" const="JVMTI_EVENT_NATIVE_METHOD_BIND" num="67">
11837 <description>
11838 A Native Method Bind event is sent when a VM binds a
11839 Java programming language native method
11840 to the address of a function that implements the native method.
11841 This will occur when the native method is called for the first time
11842 and also occurs when the JNI function <code>RegisterNatives</code> is called.
11843 This event allows the bind to be redirected to an agent-specified
11844 proxy function.
11845 This event is not sent when the native method is unbound.
11846 Typically, this proxy function will need to be specific to a
11847 particular method or, to handle the general case, automatically
11848 generated assembly code, since after instrumentation code is
11849 executed the function at the original binding
11850 address will usually be invoked.
11851 The original binding can be restored or the redirection changed
11852 by use of the JNI function <code>RegisterNatives</code>.
11853 Some events may be sent during the primordial phase, JNI and
11854 most of <jvmti/> cannot be used at this time but the method and
11855 address can be saved for use later.
11856 </description>
11857 <origin>new</origin>
11858 <capabilities>
11859 <required id="can_generate_native_method_bind_events"></required>
11860 </capabilities>
11861 <parameters>
11862 <param id="jni_env">
11863 <outptr>
11864 <struct>JNIEnv</struct>
11865 </outptr>
11866 <description>
11867 The JNI environment of the event (current) thread
11868 Will be <code>NULL</code> if sent during the primordial
11869 <functionlink id="GetPhase">phase</functionlink>.
11870 </description>
11871 </param>
11872 <param id="thread">
11873 <jthread/>
11874 <description>
11875 Thread requesting the bind
11876 </description>
11877 </param>
11878 <param id="klass">
11879 <jclass method="method"/>
11880 <description>
11881 Class of the method being bound
11882 </description>
11883 </param>
11884 <param id="method">
11885 <jmethodID class="klass"/>
11886 <description>
11887 Native method being bound
11888 </description>
11889 </param>
11890 <param id="address">
11891 <outptr><void/></outptr>
11892 <description>
11893 The address the VM is about to bind to--that is, the
11894 address of the implementation of the native method
11895 </description>
11896 </param>
11897 <param id="new_address_ptr">
11898 <agentbuf><void/></agentbuf>
11899 <description>
11900 if the referenced address is changed (that is, if
11901 <code>*new_address_ptr</code> is set), the binding
11902 will instead be made to the supplied address.
11903 </description>
11904 </param>
11905 </parameters>
11906 </event>
11907
11908 <event label="Exception"
11909 id="Exception" const="JVMTI_EVENT_EXCEPTION" filtered="thread" num="58">
11910 <description>
11911 Exception events are generated whenever an exception is first detected
11912 in a Java programming language method.
11913 Where "exception" means any <code>java.lang.Throwable</code>.
11914 The exception may have been thrown by a Java programming language or native
11915 method, but in the case of native methods, the event is not generated
11916 until the exception is first seen by a Java programming language method. If an exception is
11917 set and cleared in a native method (and thus is never visible to Java programming language code),
11918 no exception event is generated.
11919 <p/>
11920 The <code>method</code> and <code>location</code>
11921 parameters uniquely identify the current location
11922 (where the exception was detected) and allow
11923 the mapping to source file and line number when that information is
11924 available. The <code>exception</code> field identifies the thrown
11925 exception object. The <code>catch_method</code>
11926 and <code>catch_location</code> identify the location of the catch clause,
11927 if any, that handles the thrown exception. If there is no such catch clause,
11928 each field is set to 0. There is no guarantee that the thread will ever
11929 reach this catch clause. If there are native methods on the call stack
11930 between the throw location and the catch clause, the exception may
11931 be reset by one of those native methods.
11932 Similarly, exceptions that are reported as uncaught (<code>catch_klass</code>
11933 et al. set to 0) may in fact be caught by native code.
11934 Agents can check for these occurrences by monitoring
11935 <eventlink id="ExceptionCatch"></eventlink> events.
11936 Note that finally clauses are implemented as catch and re-throw. Therefore they
11937 will be reported in the catch location.
11938 </description>
11939 <origin>jvmdi</origin>
11940 <capabilities>
11941 <required id="can_generate_exception_events"></required>
11942 </capabilities>
11943 <parameters>
11944 <param id="jni_env">
11945 <outptr>
11946 <struct>JNIEnv</struct>
11947 </outptr>
11948 <description>
11949 The JNI environment of the event (current) thread
11950 </description>
11951 </param>
11952 <param id="thread">
11953 <jthread/>
11954 <description>
11955 Thread generating the exception
11956 </description>
11957 </param>
11958 <param id="klass">
11959 <jclass method="method"/>
11960 <description>
11961 Class generating the exception
11962 </description>
11963 </param>
11964 <param id="method">
11965 <jmethodID class="klass"/>
11966 <description>
11967 Method generating the exception
11968 </description>
11969 </param>
11970 <param id="location">
11971 <jlocation/>
11972 <description>
11973 Location where exception occurred
11974 </description>
11975 </param>
11976 <param id="exception">
11977 <jobject/>
11978 <description>
11979 The exception being thrown
11980 </description>
11981 </param>
11982 <param id="catch_klass">
11983 <jclass method="catch_method"/>
11984 <description>
11985 Class that will catch the exception, or <code>NULL</code> if no known catch
11986 </description>
11987 </param>
11988 <param id="catch_method">
11989 <jmethodID class="catch_klass"/>
11990 <description>
11991 Method that will catch the exception, or <code>NULL</code> if no known catch
11992 </description>
11993 </param>
11994 <param id="catch_location">
11995 <jlocation/>
11996 <description>
11997 location which will catch the exception or zero if no known catch
11998 </description>
11999 </param>
12000 </parameters>
12001 </event>
12002
12003 <event label="Exception Catch"
12004 id="ExceptionCatch" const="JVMTI_EVENT_EXCEPTION_CATCH" filtered="thread" num="59">
12005 <description>
12006 Exception catch events are generated whenever a thrown exception is caught.
12007 Where "exception" means any <code>java.lang.Throwable</code>.
12008 If the exception is caught in a Java programming language method, the event is generated
12009 when the catch clause is reached. If the exception is caught in a native
12010 method, the event is generated as soon as control is returned to a Java programming language
12011 method. Exception catch events are generated for any exception for which
12012 a throw was detected in a Java programming language method.
12013 Note that finally clauses are implemented as catch and re-throw. Therefore they
12014 will generate exception catch events.
12015 <p/>
12016 The <code>method</code> and <code>location</code>
12017 parameters uniquely identify the current location
12018 and allow the mapping to source file and line number when that information is
12019 available. For exceptions caught in a Java programming language method, the
12020 <code>exception</code> object identifies the exception object. Exceptions
12021 caught in native methods are not necessarily available by the time the
12022 exception catch is reported, so the <code>exception</code> field is set
12023 to <code>NULL</code>.
12024 </description>
12025 <origin>jvmdi</origin>
12026 <capabilities>
12027 <required id="can_generate_exception_events"></required>
12028 </capabilities>
12029 <parameters>
12030 <param id="jni_env">
12031 <outptr>
12032 <struct>JNIEnv</struct>
12033 </outptr>
12034 <description>
12035 The JNI environment of the event (current) thread
12036 </description>
12037 </param>
12038 <param id="thread">
12039 <jthread/>
12040 <description>
12041 Thread catching the exception
12042 </description>
12043 </param>
12044 <param id="klass">
12045 <jclass method="method"/>
12046 <description>
12047 Class catching the exception
12048 </description>
12049 </param>
12050 <param id="method">
12051 <jmethodID class="klass"/>
12052 <description>
12053 Method catching the exception
12054 </description>
12055 </param>
12056 <param id="location">
12057 <jlocation/>
12058 <description>
12059 Location where exception is being caught
12060 </description>
12061 </param>
12062 <param id="exception">
12063 <jobject/>
12064 <description>
12065 Exception being caught
12066 </description>
12067 </param>
12068 </parameters>
12069 </event>
12070
12071 <event label="Thread Start"
12072 id="ThreadStart" const="JVMTI_EVENT_THREAD_START" num="52" phase="start">
12073 <description>
12074 Thread start events are generated by a new thread before its initial
12075 method executes.
12076 <p/>
12077 A thread may be listed in the array returned by
12078 <functionlink id="GetAllThreads"></functionlink>
12079 before its thread start event is generated.
12080 It is possible for other events to be generated
12081 on a thread before its thread start event.
12082 <p/>
12083 The event is sent on the newly started <paramlink id="thread"></paramlink>.
12084 </description>
12085 <origin>jvmdi</origin>
12086 <capabilities>
12087 </capabilities>
12088 <parameters>
12089 <param id="jni_env">
12090 <outptr>
12091 <struct>JNIEnv</struct>
12092 </outptr>
12093 <description>
12094 The JNI environment of the event (current) thread.
12095 </description>
12096 </param>
12097 <param id="thread">
12098 <jthread/>
12099 <description>
12100 Thread starting
12101 </description>
12102 </param>
12103 </parameters>
12104 </event>
12105
12106 <event label="Thread End"
12107 id="ThreadEnd" const="JVMTI_EVENT_THREAD_END" filtered="thread" num="53" phase="start">
12108 <description>
12109 Thread end events are generated by a terminating thread
12110 after its initial method has finished execution.
12111 <p/>
12112 A thread may be listed in the array returned by
12113 <functionlink id="GetAllThreads"></functionlink>
12114 after its thread end event is generated.
12115 No events are generated on a thread
12116 after its thread end event.
12117 <p/>
12118 The event is sent on the dying <paramlink id="thread"></paramlink>.
12119 </description>
12120 <origin>jvmdi</origin>
12121 <capabilities>
12122 </capabilities>
12123 <parameters>
12124 <param id="jni_env">
12125 <outptr>
12126 <struct>JNIEnv</struct>
12127 </outptr>
12128 <description>
12129 The JNI environment of the event (current) thread.
12130 </description>
12131 </param>
12132 <param id="thread">
12133 <jthread/>
12134 <description>
12135 Thread ending
12136 </description>
12137 </param>
12138 </parameters>
12139 </event>
12140
12141 <event label="Class Load"
12142 id="ClassLoad" const="JVMTI_EVENT_CLASS_LOAD" filtered="thread" phase="start" num="55">
12143 <description>
12144 A class load event is generated when a class is first loaded. The order
12145 of class load events generated by a particular thread are guaranteed
12146 to match the order of class loading within that thread.
12147 Array class creation does not generate a class load event.
12148 The creation of a primitive class (for example, java.lang.Integer.TYPE)
12149 does not generate a class load event.
12150 <p/>
12151 This event is sent at an early stage in loading the class. As
12152 a result the class should be used carefully. Note, for example,
12153 that methods and fields are not yet loaded, so queries for methods,
12154 fields, subclasses, and so on will not give correct results.
12155 See "Loading of Classes and Interfaces" in the <i>Java Language
12156 Specification</i>. For most
12157 purposes the <eventlink id="ClassPrepare"></eventlink> event will
12158 be more useful.
12159 </description>
12160 <origin>jvmdi</origin>
12161 <capabilities>
12162 </capabilities>
12163 <parameters>
12164 <param id="jni_env">
12165 <outptr>
12166 <struct>JNIEnv</struct>
12167 </outptr>
12168 <description>
12169 The JNI environment of the event (current) thread
12170 </description>
12171 </param>
12172 <param id="thread">
12173 <jthread/>
12174 <description>
12175 Thread loading the class
12176 </description>
12177 </param>
12178 <param id="klass">
12179 <jclass/>
12180 <description>
12181 Class being loaded
12182 </description>
12183 </param>
12184 </parameters>
12185 </event>
12186
12187 <elide>
12188 <event label="Class Unload"
12189 id="ClassUnload" const="JVMTI_EVENT_CLASS_UNLOAD" num="57">
12190 <description>
12191 A class unload event is generated when the class is about to be unloaded.
12192 Class unload events take place during garbage collection and must be
12193 handled extremely carefully. The garbage collector holds many locks
12194 and has suspended all other threads, so the event handler cannot depend
12195 on the ability to acquire any locks. The class unload event handler should
12196 do as little as possible, perhaps by queuing information to be processed
12197 later. In particular, the <code>jclass</code> should be used only in
12198 the JNI function <code>isSameObject</code> or in the following <jvmti/> functions:
12199 <ul>
12200 <li><functionlink id="GetClassSignature"></functionlink></li>
12201 <li><functionlink id="GetSourceFileName"></functionlink></li>
12202 <li><functionlink id="IsInterface"></functionlink></li>
12203 <li><functionlink id="IsArrayClass"></functionlink></li>
12204 </ul>
12205 </description>
12206 <origin>jvmdi</origin>
12207 <capabilities>
12208 </capabilities>
12209 <parameters>
12210 <param id="jni_env">
12211 <outptr>
12212 <struct>JNIEnv</struct>
12213 </outptr>
12214 <description>
12215 The JNI environment of the event (current) thread
12216 </description>
12217 </param>
12218 <param id="thread">
12219 <jthread/>
12220 <description>
12221 Thread generating the class unload
12222 </description>
12223 </param>
12224 <param id="klass">
12225 <jclass/>
12226 <description>
12227 Class being unloaded
12228 </description>
12229 </param>
12230 </parameters>
12231 </event>
12232 </elide>
12233
12234 <event label="Class Prepare"
12235 id="ClassPrepare" const="JVMTI_EVENT_CLASS_PREPARE" filtered="thread" phase="start" num="56">
12236 <description>
12237 A class prepare event is generated when class preparation is complete.
12238 At this point, class fields, methods, and implemented interfaces are
12239 available, and no code from the class has been executed. Since array
12240 classes never have fields or methods, class prepare events are not
12241 generated for them. Class prepare events are not generated for
12242 primitive classes (for example, <code>java.lang.Integer.TYPE</code>).
12243 </description>
12244 <origin>jvmdi</origin>
12245 <capabilities>
12246 </capabilities>
12247 <parameters>
12248 <param id="jni_env">
12249 <outptr>
12250 <struct>JNIEnv</struct>
12251 </outptr>
12252 <description>
12253 The JNI environment of the event (current) thread
12254 </description>
12255 </param>
12256 <param id="thread">
12257 <jthread/>
12258 <description>
12259 Thread generating the class prepare
12260 </description>
12261 </param>
12262 <param id="klass">
12263 <jclass/>
12264 <description>
12265 Class being prepared
12266 </description>
12267 </param>
12268 </parameters>
12269 </event>
12270
12271 <event label="Class File Load Hook" phase="any"
12272 id="ClassFileLoadHook" const="JVMTI_EVENT_CLASS_FILE_LOAD_HOOK" num="54">
12273 <description>
12274 This event is sent when the VM obtains class file data,
12275 but before it constructs
12276 the in-memory representation for that class.
12277 This event is also sent when the class is being modified by the
12278 <functionlink id="RetransformClasses"/> function or
12279 the <functionlink id="RedefineClasses"/> function,
12280 called in any <jvmti/> environment.
12281 The agent can instrument
12282 the existing class file data sent by the VM to include profiling/debugging hooks.
12283 See the description of
12284 <internallink id="bci">bytecode instrumentation</internallink>
12285 for usage information.
12286 <p/>
12287 This event may be sent before the VM is initialized (the primordial
12288 <functionlink id="GetPhase">phase</functionlink>). During this time
12289 no VM resources should be created. Some classes might not be compatible
12290 with the function (eg. ROMized classes) and this event will not be
12291 generated for these classes.
12292 <p/>
12293 The agent must allocate the space for the modified
12294 class file data buffer
12295 using the memory allocation function
12296 <functionlink id="Allocate"></functionlink> because the
12297 VM is responsible for freeing the new class file data buffer
12298 using <functionlink id="Deallocate"></functionlink>.
12299 Note that <functionlink id="Allocate"></functionlink>
12300 is permitted during the primordial phase.
12301 <p/>
12302 If the agent wishes to modify the class file, it must set
12303 <code>new_class_data</code> to point
12304 to the newly instrumented class file data buffer and set
12305 <code>new_class_data_len</code> to the length of that
12306 buffer before returning
12307 from this call. If no modification is desired, the agent simply
12308 does not set <code>new_class_data</code>. If multiple agents
12309 have enabled this event the results are chained. That is, if
12310 <code>new_class_data</code> has been set, it becomes the
12311 <code>class_data</code> for the next agent.
12312 <p/>
12313 The order that this event is sent to each environment differs
12314 from other events.
12315 This event is sent to environments in the following order:
12316 <ul>
12317 <li><fieldlink id="can_retransform_classes"
12318 struct="jvmtiCapabilities">retransformation
12319 incapable</fieldlink>
12320 environments, in the
12321 order in which they were created
12322 </li>
12323 <li><fieldlink id="can_retransform_classes"
12324 struct="jvmtiCapabilities">retransformation
12325 capable</fieldlink>
12326 environments, in the
12327 order in which they were created
12328 </li>
12329 </ul>
12330 When triggered by <functionlink id="RetransformClasses"/>,
12331 this event is sent only to <fieldlink id="can_retransform_classes"
12332 struct="jvmtiCapabilities">retransformation
12333 capable</fieldlink>
12334 environments.
12335 </description>
12336 <origin>jvmpi</origin>
12337 <capabilities>
12338 <capability id="can_generate_all_class_hook_events"></capability>
12339 </capabilities>
12340 <parameters>
12341 <param id="jni_env">
12342 <outptr>
12343 <struct>JNIEnv</struct>
12344 </outptr>
12345 <description>
12346 The JNI environment of the event (current) thread.
12347 Will be <code>NULL</code> if sent during the primordial
12348 <functionlink id="GetPhase">phase</functionlink>.
12349 </description>
12350 </param>
12351 <param id="class_being_redefined">
12352 <jclass/>
12353 <description>
12354 The class being
12355 <functionlink id="RedefineClasses">redefined</functionlink> or
12356 <functionlink id="RetransformClasses">retransformed</functionlink>.
12357 <code>NULL</code> if sent by class load.
12358 </description>
12359 </param>
12360 <param id="loader">
12361 <jobject/>
12362 <description>
12363 The class loader loading the class.
12364 <code>NULL</code> if the bootstrap class loader.
12365 </description>
12366 </param>
12367 <param id="name">
12368 <vmbuf><char/></vmbuf>
12369 <description>
12370 Name of class being loaded as a VM internal qualified name
12371 (for example, "java/util/List"), encoded as a
12372 <internallink id="mUTF">modified UTF-8</internallink> string.
12373 Note: if the class is defined with a <code>NULL</code> name or
12374 without a name specified, <code>name</code> will be <code>NULL</code>.
12375 </description>
12376 </param>
12377 <param id="protection_domain">
12378 <jobject/>
12379 <description>
12380 The <code>ProtectionDomain</code> of the class.
12381 </description>
12382 </param>
12383 <param id="class_data_len">
12384 <jint/>
12385 <description>
12386 Length of current class file data buffer.
12387 </description>
12388 </param>
12389 <param id="class_data">
12390 <vmbuf><uchar/></vmbuf>
12391 <description>
12392 Pointer to the current class file data buffer.
12393 </description>
12394 </param>
12395 <param id="new_class_data_len">
12396 <outptr><jint/></outptr>
12397 <description>
12398 Pointer to the length of the new class file data buffer.
12399 </description>
12400 </param>
12401 <param id="new_class_data">
12402 <agentbuf incount="new_class_data_len"><uchar/></agentbuf>
12403 <description>
12404 Pointer to the pointer to the instrumented class file data buffer.
12405 </description>
12406 </param>
12407 </parameters>
12408 </event>
12409
12410 <event label="VM Start Event"
12411 id="VMStart" const="JVMTI_EVENT_VM_START" num="57" phase="start">
12412 <description>
12413 The VM initialization event signals the start of the VM.
12414 At this time JNI is live but the VM is not yet fully initialized.
12415 Once this event is generated, the agent is free to call any JNI function.
12416 This event signals the beginning of the start phase,
12417 <jvmti/> functions permitted in the start phase may be called.
12418 <p/>
12419 In the case of VM start-up failure, this event will not be sent.
12420 </description>
12421 <origin>jvmdi</origin>
12422 <capabilities>
12423 </capabilities>
12424 <parameters>
12425 <param id="jni_env">
12426 <outptr>
12427 <struct>JNIEnv</struct>
12428 </outptr>
12429 <description>
12430 The JNI environment of the event (current) thread.
12431 </description>
12432 </param>
12433 </parameters>
12434 </event>
12435
12436 <event label="VM Initialization Event"
12437 id="VMInit" const="JVMTI_EVENT_VM_INIT" num="50">
12438 <description>
12439 The VM initialization event signals the completion of VM initialization. Once
12440 this event is generated, the agent is free to call any JNI or <jvmti/>
12441 function. The VM initialization event can be preceded by or can be concurrent
12442 with other events, but
12443 the preceding events should be handled carefully, if at all, because the
12444 VM has not completed its initialization. The thread start event for the
12445 main application thread is guaranteed not to occur until after the
12446 handler for the VM initialization event returns.
12447 <p/>
12448 In the case of VM start-up failure, this event will not be sent.
12449 </description>
12450 <origin>jvmdi</origin>
12451 <capabilities>
12452 </capabilities>
12453 <parameters>
12454 <param id="jni_env">
12455 <outptr>
12456 <struct>JNIEnv</struct>
12457 </outptr>
12458 <description>
12459 The JNI environment of the event (current) thread.
12460 </description>
12461 </param>
12462 <param id="thread">
12463 <jthread/>
12464 <description>
12465 The initial thread
12466 </description>
12467 </param>
12468 </parameters>
12469 </event>
12470
12471 <event label="VM Death Event"
12472 id="VMDeath" const="JVMTI_EVENT_VM_DEATH" num="51">
12473 <description>
12474 The VM death event notifies the agent of the termination of the VM.
12475 No events will occur after the VMDeath event.
12476 <p/>
12477 In the case of VM start-up failure, this event will not be sent.
12478 Note that <internallink id="onunload">Agent_OnUnload</internallink>
12479 will still be called in these cases.
12480 </description>
12481 <origin>jvmdi</origin>
12482 <capabilities>
12483 </capabilities>
12484 <parameters>
12485 <param id="jni_env">
12486 <outptr>
12487 <struct>JNIEnv</struct>
12488 </outptr>
12489 <description>
12490 The JNI environment of the event (current) thread
12491 </description>
12492 </param>
12493 </parameters>
12494 </event>
12495
12496 <event label="Compiled Method Load"
12497 id="CompiledMethodLoad" const="JVMTI_EVENT_COMPILED_METHOD_LOAD" num="68">
12498 <description>
12499 Sent when a method is compiled and loaded into memory by the VM.
12500 If it is unloaded, the <eventlink id="CompiledMethodUnload"/> event is sent.
12501 If it is moved, the <eventlink id="CompiledMethodUnload"/> event is sent,
12502 followed by a new <code>CompiledMethodLoad</code> event.
12503 Note that a single method may have multiple compiled forms, and that
12504 this event will be sent for each form.
12505 Note also that several methods may be inlined into a single
12506 address range, and that this event will be sent for each method.
12507 <p/>
12508 These events can be sent after their initial occurrence with
12509 <functionlink id="GenerateEvents"></functionlink>.
12510 </description>
12511 <origin>jvmpi</origin>
12512 <typedef id="jvmtiAddrLocationMap" label="Native address to location entry">
12513 <field id="start_address">
12514 <vmbuf><void/></vmbuf>
12515 <description>
12516 Starting native address of code corresponding to a location
12517 </description>
12518 </field>
12519 <field id="location">
12520 <jlocation/>
12521 <description>
12522 Corresponding location. See
12523 <functionlink id="GetJLocationFormat"></functionlink>
12524 for the meaning of location.
12525 </description>
12526 </field>
12527 </typedef>
12528 <capabilities>
12529 <required id="can_generate_compiled_method_load_events"></required>
12530 </capabilities>
12531 <parameters>
12532 <param id="klass">
12533 <jclass method="method"/>
12534 <description>
12535 Class of the method being compiled and loaded
12536 </description>
12537 </param>
12538 <param id="method">
12539 <jmethodID class="klass"/>
12540 <description>
12541 Method being compiled and loaded
12542 </description>
12543 </param>
12544 <param id="code_size">
12545 <jint/>
12546 <description>
12547 Size of compiled code
12548 </description>
12549 </param>
12550 <param id="code_addr">
12551 <vmbuf><void/></vmbuf>
12552 <description>
12553 Address where compiled method code is loaded
12554 </description>
12555 </param>
12556 <param id="map_length">
12557 <jint/>
12558 <description>
12559 Number of <typelink id="jvmtiAddrLocationMap"></typelink>
12560 entries in the address map.
12561 Zero if mapping information cannot be supplied.
12562 </description>
12563 </param>
12564 <param id="map">
12565 <vmbuf><struct>jvmtiAddrLocationMap</struct></vmbuf>
12566 <description>
12567 Map from native addresses to location.
12568 The native address range of each entry is from
12569 <fieldlink id="start_address" struct="jvmtiAddrLocationMap"></fieldlink>
12570 to <code>start_address-1</code> of the next entry.
12571 <code>NULL</code> if mapping information cannot be supplied.
12572 </description>
12573 </param>
12574 <param id="compile_info">
12575 <vmbuf><void/></vmbuf>
12576 <description>
12577 VM-specific compilation information.
12578 The referenced compile information is managed by the VM
12579 and must not depend on the agent for collection.
12580 A VM implementation defines the content and lifetime
12581 of the information.
12582 </description>
12583 </param>
12584 </parameters>
12585 </event>
12586
12587 <event label="Compiled Method Unload"
12588 id="CompiledMethodUnload" const="JVMTI_EVENT_COMPILED_METHOD_UNLOAD" num="69">
12589 <description>
12590 Sent when a compiled method is unloaded from memory.
12591 This event might not be sent on the thread which performed the unload.
12592 This event may be sent sometime after the unload occurs, but
12593 will be sent before the memory is reused
12594 by a newly generated compiled method. This event may be sent after
12595 the class is unloaded.
12596 </description>
12597 <origin>jvmpi</origin>
12598 <capabilities>
12599 <required id="can_generate_compiled_method_load_events"></required>
12600 </capabilities>
12601 <parameters>
12602 <param id="klass">
12603 <jclass method="method"/>
12604 <description>
12605 Class of the compiled method being unloaded.
12606 </description>
12607 </param>
12608 <param id="method">
12609 <jmethodID class="klass"/>
12610 <description>
12611 Compiled method being unloaded.
12612 For identification of the compiled method only -- the class
12613 may be unloaded and therefore the method should not be used
12614 as an argument to further JNI or <jvmti/> functions.
12615 </description>
12616 </param>
12617 <param id="code_addr">
12618 <vmbuf><void/></vmbuf>
12619 <description>
12620 Address where compiled method code was loaded.
12621 For identification of the compiled method only --
12622 the space may have been reclaimed.
12623 </description>
12624 </param>
12625 </parameters>
12626 </event>
12627
12628 <event label="Dynamic Code Generated" phase="any"
12629 id="DynamicCodeGenerated" const="JVMTI_EVENT_DYNAMIC_CODE_GENERATED" num="70">
12630 <description>
12631 Sent when a component of the virtual machine is generated dynamically.
12632 This does not correspond to Java programming language code that is
12633 compiled--see <eventlink id="CompiledMethodLoad"></eventlink>.
12634 This is for native code--for example, an interpreter that is generated
12635 differently depending on command-line options.
12636 <p/>
12637 Note that this event has no controlling capability.
12638 If a VM cannot generate these events, it simply does not send any.
12639 <p/>
12640 These events can be sent after their initial occurrence with
12641 <functionlink id="GenerateEvents"></functionlink>.
12642 </description>
12643 <origin>jvmpi</origin>
12644 <capabilities>
12645 </capabilities>
12646 <parameters>
12647 <param id="name">
12648 <vmbuf><char/></vmbuf>
12649 <description>
12650 Name of the code, encoded as a
12651 <internallink id="mUTF">modified UTF-8</internallink> string.
12652 Intended for display to an end-user.
12653 The name might not be unique.
12654 </description>
12655 </param>
12656 <param id="address">
12657 <vmbuf><void/></vmbuf>
12658 <description>
12659 Native address of the code
12660 </description>
12661 </param>
12662 <param id="length">
12663 <jint/>
12664 <description>
12665 Length in bytes of the code
12666 </description>
12667 </param>
12668 </parameters>
12669 </event>
12670
12671 <event label="Data Dump Request"
12672 id="DataDumpRequest" const="JVMTI_EVENT_DATA_DUMP_REQUEST" num="71">
12673 <description>
12674 Sent by the VM to request the agent to dump its data. This
12675 is just a hint and the agent need not react to this event.
12676 This is useful for processing command-line signals from users. For
12677 example, in the Java 2 SDK a CTRL-Break on Win32 and a CTRL-\ on Solaris
12678 causes the VM to send this event to the agent.
12679 </description>
12680 <origin>jvmpi</origin>
12681 <capabilities>
12682 </capabilities>
12683 <parameters>
12684 </parameters>
12685 </event>
12686
12687 <event label="Monitor Contended Enter"
12688 id="MonitorContendedEnter" const="JVMTI_EVENT_MONITOR_CONTENDED_ENTER" filtered="thread" num="75">
12689 <description>
12690 Sent when a thread is attempting to enter a Java programming language
12691 monitor already acquired by another thread.
12692 </description>
12693 <origin>jvmpi</origin>
12694 <capabilities>
12695 <required id="can_generate_monitor_events"></required>
12696 </capabilities>
12697 <parameters>
12698 <param id="jni_env">
12699 <outptr>
12700 <struct>JNIEnv</struct>
12701 </outptr>
12702 <description>
12703 The JNI environment of the event (current) thread
12704 </description>
12705 </param>
12706 <param id="thread">
12707 <jthread/>
12708 <description>
12709 JNI local reference to the thread
12710 attempting to enter the monitor
12711 </description>
12712 </param>
12713 <param id="object">
12714 <jobject/>
12715 <description>
12716 JNI local reference to the monitor
12717 </description>
12718 </param>
12719 </parameters>
12720 </event>
12721
12722 <event label="Monitor Contended Entered"
12723 id="MonitorContendedEntered" const="JVMTI_EVENT_MONITOR_CONTENDED_ENTERED" filtered="thread" num="76">
12724 <description>
12725 Sent when a thread enters a Java programming language
12726 monitor after waiting for it to be released by another thread.
12727 </description>
12728 <origin>jvmpi</origin>
12729 <capabilities>
12730 <required id="can_generate_monitor_events"></required>
12731 </capabilities>
12732 <parameters>
12733 <param id="jni_env">
12734 <outptr>
12735 <struct>JNIEnv</struct>
12736 </outptr>
12737 <description>
12738 The JNI environment of the event (current) thread
12739 </description>
12740 </param>
12741 <param id="thread">
12742 <jthread/>
12743 <description>
12744 JNI local reference to the thread entering
12745 the monitor
12746 </description>
12747 </param>
12748 <param id="object">
12749 <jobject/>
12750 <description>
12751 JNI local reference to the monitor
12752 </description>
12753 </param>
12754 </parameters>
12755 </event>
12756
12757 <event label="Monitor Wait"
12758 id="MonitorWait" const="JVMTI_EVENT_MONITOR_WAIT" filtered="thread" num="73">
12759 <description>
12760 Sent when a thread is about to wait on an object.
12761 </description>
12762 <origin>jvmpi</origin>
12763 <capabilities>
12764 <required id="can_generate_monitor_events"></required>
12765 </capabilities>
12766 <parameters>
12767 <param id="jni_env">
12768 <outptr>
12769 <struct>JNIEnv</struct>
12770 </outptr>
12771 <description>
12772 The JNI environment of the event (current) thread
12773 </description>
12774 </param>
12775 <param id="thread">
12776 <jthread/>
12777 <description>
12778 JNI local reference to the thread about to wait
12779 </description>
12780 </param>
12781 <param id="object">
12782 <jobject/>
12783 <description>
12784 JNI local reference to the monitor
12785 </description>
12786 </param>
12787 <param id="timeout">
12788 <jlong/>
12789 <description>
12790 The number of milliseconds the thread will wait
12791 </description>
12792 </param>
12793 </parameters>
12794 </event>
12795
12796 <event label="Monitor Waited"
12797 id="MonitorWaited" const="JVMTI_EVENT_MONITOR_WAITED" filtered="thread" num="74">
12798 <description>
12799 Sent when a thread finishes waiting on an object.
12800 </description>
12801 <origin>jvmpi</origin>
12802 <capabilities>
12803 <required id="can_generate_monitor_events"></required>
12804 </capabilities>
12805 <parameters>
12806 <param id="jni_env">
12807 <outptr>
12808 <struct>JNIEnv</struct>
12809 </outptr>
12810 <description>
12811 The JNI environment of the event (current) thread
12812 </description>
12813 </param>
12814 <param id="thread">
12815 <jthread/>
12816 <description>
12817 JNI local reference to the thread that was finished waiting
12818 </description>
12819 </param>
12820 <param id="object">
12821 <jobject/>
12822 <description>
12823 JNI local reference to the monitor.
12824 </description>
12825 </param>
12826 <param id="timed_out">
12827 <jboolean/>
12828 <description>
12829 True if the monitor timed out
12830 </description>
12831 </param>
12832 </parameters>
12833 </event>
12834
12835 <event label="Resource Exhausted"
12836 id="ResourceExhausted" const="JVMTI_EVENT_RESOURCE_EXHAUSTED" num="80"
12837 since="1.1">
12838 <description>
12839 Sent when a VM resource needed by a running application has been exhausted.
12840 Except as required by the optional capabilities, the set of resources
12841 which report exhaustion is implementation dependent.
12842 <p/>
12843 The following bit flags define the properties of the resource exhaustion:
12844 <constants id="jvmtiResourceExhaustionFlags"
12845 label="Resource Exhaustion Flags"
12846 kind="bits"
12847 since="1.1">
12848 <constant id="JVMTI_RESOURCE_EXHAUSTED_OOM_ERROR" num="0x0001">
12849 After this event returns, the VM will throw a
12850 <code>java.lang.OutOfMemoryError</code>.
12851 </constant>
12852 <constant id="JVMTI_RESOURCE_EXHAUSTED_JAVA_HEAP" num="0x0002">
12853 The VM was unable to allocate memory from the <tm>Java</tm>
12854 platform <i>heap</i>.
12855 The <i>heap</i> is the runtime
12856 data area from which memory for all class instances and
12857 arrays are allocated.
12858 </constant>
12859 <constant id="JVMTI_RESOURCE_EXHAUSTED_THREADS" num="0x0004">
12860 The VM was unable to create a thread.
12861 </constant>
12862 </constants>
12863 </description>
12864 <origin>new</origin>
12865 <capabilities>
12866 <capability id="can_generate_resource_exhaustion_heap_events">
12867 Can generate events when the VM is unable to allocate memory from the
12868 <internallink id="JVMTI_RESOURCE_EXHAUSTED_JAVA_HEAP">heap</internallink>.
12869 </capability>
12870 <capability id="can_generate_resource_exhaustion_threads_events">
12871 Can generate events when the VM is unable to
12872 <internallink id="JVMTI_RESOURCE_EXHAUSTED_THREADS">create
12873 a thread</internallink>.
12874 </capability>
12875 </capabilities>
12876 <parameters>
12877 <param id="jni_env">
12878 <outptr>
12879 <struct>JNIEnv</struct>
12880 </outptr>
12881 <description>
12882 The JNI environment of the event (current) thread
12883 </description>
12884 </param>
12885 <param id="flags">
12886 <jint/>
12887 <description>
12888 Flags defining the properties of the of resource exhaustion
12889 as specified by the
12890 <internallink id="jvmtiResourceExhaustionFlags">Resource
12891 Exhaustion Flags</internallink>.
12892 </description>
12893 </param>
12894 <param id="reserved">
12895 <vmbuf><void/></vmbuf>
12896 <description>
12897 Reserved.
12898 </description>
12899 </param>
12900 <param id="description">
12901 <vmbuf><char/></vmbuf>
12902 <description>
12903 Description of the resource exhaustion, encoded as a
12904 <internallink id="mUTF">modified UTF-8</internallink> string.
12905 </description>
12906 </param>
12907 </parameters>
12908 </event>
12909
12910 <event label="VM Object Allocation"
12911 id="VMObjectAlloc" const="JVMTI_EVENT_VM_OBJECT_ALLOC" num="84">
12912 <description>
12913 Sent when a method causes the virtual machine to allocate an
12914 Object visible to Java programming language code and the
12915 allocation is not detectable by other intrumentation mechanisms.
12916 Generally object allocation should be detected by instrumenting
12917 the bytecodes of allocating methods.
12918 Object allocation generated in native code by JNI function
12919 calls should be detected using
12920 <internallink id="jniIntercept">JNI function interception</internallink>.
12921 Some methods might not have associated bytecodes and are not
12922 native methods, they instead are executed directly by the
12923 VM. These methods should send this event.
12924 Virtual machines which are incapable of bytecode instrumentation
12925 for some or all of their methods can send this event.
12926 <p/>
12927 Typical examples where this event might be sent:
12928 <ul>
12929 <li>Reflection -- for example, <code>java.lang.Class.newInstance()</code></li>
12930 <li>Methods not represented by bytecodes -- for example, VM intrinsics and
12931 J2ME preloaded classes</li>
12932 </ul>
12933 Cases where this event would not be generated:
12934 <ul>
12935 <li>Allocation due to bytecodes -- for example, the <code>new</code>
12936 and <code>newarray</code> VM instructions</li>
12937 <li>Allocation due to JNI function calls -- for example,
12938 <code>AllocObject</code></li>
12939 <li>Allocations during VM initialization</li>
12940 <li>VM internal objects</li>
12941 </ul>
12942 </description>
12943 <origin>new</origin>
12944 <capabilities>
12945 <required id="can_generate_vm_object_alloc_events"></required>
12946 </capabilities>
12947 <parameters>
12948 <param id="jni_env">
12949 <outptr>
12950 <struct>JNIEnv</struct>
12951 </outptr>
12952 <description>
12953 The JNI environment of the event (current) thread
12954 </description>
12955 </param>
12956 <param id="thread">
12957 <jthread/>
12958 <description>
12959 Thread allocating the object.
12960 </description>
12961 </param>
12962 <param id="object">
12963 <jobject/>
12964 <description>
12965 JNI local reference to the object that was allocated
12966 </description>
12967 </param>
12968 <param id="object_klass">
12969 <jclass/>
12970 <description>
12971 JNI local reference to the class of the object
12972 </description>
12973 </param>
12974 <param id="size">
12975 <jlong/>
12976 <description>
12977 Size of the object (in bytes). See <functionlink id="GetObjectSize"/>.
12978 </description>
12979 </param>
12980 </parameters>
12981 </event>
12982
12983 <event label="Object Free"
12984 id="ObjectFree" const="JVMTI_EVENT_OBJECT_FREE" num="83">
12985 <description>
12986 An Object Free event is sent when the garbage collector frees an object.
12987 Events are only sent for tagged objects--see
12988 <internallink id="Heap">heap functions</internallink>.
12989 <p/>
12990 The event handler must not use JNI functions and
12991 must not use <jvmti/> functions except those which
12992 specifically allow such use (see the raw monitor, memory management,
12993 and environment local storage functions).
12994 </description>
12995 <origin>new</origin>
12996 <capabilities>
12997 <required id="can_generate_object_free_events"></required>
12998 </capabilities>
12999 <parameters>
13000 <param id="tag">
13001 <jlong/>
13002 <description>
13003 The freed object's tag
13004 </description>
13005 </param>
13006 </parameters>
13007 </event>
13008
13009 <event label="Garbage Collection Start"
13010 id="GarbageCollectionStart" const="JVMTI_EVENT_GARBAGE_COLLECTION_START" num="81">
13011 <description>
13012 A Garbage Collection Start event is sent when a full cycle
13013 garbage collection begins.
13014 Only stop-the-world collections are reported--that is, collections during
13015 which all threads cease to modify the state of the Java virtual machine.
13016 This means that some collectors will never generate these events.
13017 This event is sent while the VM is still stopped, thus
13018 the event handler must not use JNI functions and
13019 must not use <jvmti/> functions except those which
13020 specifically allow such use (see the raw monitor, memory management,
13021 and environment local storage functions).
13022 <p/>
13023 This event is always sent as a matched pair with
13024 <eventlink id="GarbageCollectionFinish"/>
13025 (assuming both events are enabled) and no garbage collection
13026 events will occur between them.
13027 </description>
13028 <origin>new</origin>
13029 <capabilities>
13030 <required id="can_generate_garbage_collection_events"></required>
13031 </capabilities>
13032 <parameters>
13033 </parameters>
13034 </event>
13035
13036 <event label="Garbage Collection Finish"
13037 id="GarbageCollectionFinish" const="JVMTI_EVENT_GARBAGE_COLLECTION_FINISH" num="82">
13038 <description>
13039 A Garbage Collection Finish event is sent when a full
13040 garbage collection cycle ends.
13041 This event is sent while the VM is still stopped, thus
13042 the event handler must not use JNI functions and
13043 must not use <jvmti/> functions except those which
13044 specifically allow such use (see the raw monitor, memory management,
13045 and environment local storage functions).
13046 <p/>
13047 Some agents may need to do post garbage collection operations that
13048 require the use of the disallowed <jvmti/> or JNI functions. For these
13049 cases an agent thread can be created which waits on a raw monitor,
13050 and the handler for the Garbage Collection Finish event simply
13051 notifies the raw monitor
13052 <p/>
13053 This event is always sent as a matched pair with
13054 <eventlink id="GarbageCollectionStart"/> (assuming both events are enabled).
13055 <issue>
13056 The most important use of this event is to provide timing information,
13057 and thus additional information is not required. However,
13058 information about the collection which is "free" should be included -
13059 what that information is needs to be determined.
13060 </issue>
13061 </description>
13062 <origin>new</origin>
13063 <capabilities>
13064 <required id="can_generate_garbage_collection_events"></required>
13065 </capabilities>
13066 <parameters>
13067 </parameters>
13068 </event>
13069
13070 <elide>
13071 <event label="Verbose Output" phase="any"
13072 id="VerboseOutput" const="JVMTI_EVENT_VERBOSE_OUTPUT" num="85">
13073 <description>
13074 Send verbose messages as strings.
13075 <issue>
13076 This format is extremely fragile, as it can change with each
13077 platform, collector and version. Alternatives include:
13078 <ul>
13079 <li>building off Java programming language M and M APIs</li>
13080 <li>XML</li>
13081 <li>key/value pairs</li>
13082 <li>removing it</li>
13083 </ul>
13084 </issue>
13085 <issue>
13086 Though this seemed trivial to implement.
13087 In the RI it appears this will be quite complex.
13088 </issue>
13089 </description>
13090 <origin>new</origin>
13091 <capabilities>
13092 </capabilities>
13093 <parameters>
13094 <param id="flag">
13095 <enum>jvmtiVerboseFlag</enum>
13096 <description>
13097 Which verbose output is being sent.
13098 </description>
13099 </param>
13100 <param id="message">
13101 <vmbuf><char/></vmbuf>
13102 <description>
13103 Message text, encoded as a
13104 <internallink id="mUTF">modified UTF-8</internallink> string.
13105 </description>
13106 </param>
13107 </parameters>
13108 </event>
13109 </elide>
13110
13111 </eventsection>
13112
13113 <datasection>
13114 <intro>
13115 <jvmti/> extends the data types defined by JNI.
13116 </intro>
13117 <basetypes id="jniTypes" label="JNI Types Used in the JVM Tool Interface">
13118 <basetype id="jboolean">
13119 <description>
13120 Holds a Java programming language <code>boolean</code>.
13121 Unsigned 8 bits.
13122 </description>
13123 </basetype>
13124 <basetype id="jint">
13125 <description>
13126 Holds a Java programming language <code>int</code>.
13127 Signed 32 bits.
13128 </description>
13129 </basetype>
13130 <basetype id="jlong">
13131 <description>
13132 Holds a Java programming language <code>long</code>.
13133 Signed 64 bits.
13134 </description>
13135 </basetype>
13136 <basetype id="jfloat">
13137 <description>
13138 Holds a Java programming language <code>float</code>.
13139 32 bits.
13140 </description>
13141 </basetype>
13142 <basetype id="jdouble">
13143 <description>
13144 Holds a Java programming language <code>double</code>.
13145 64 bits.
13146 </description>
13147 </basetype>
13148 <basetype id="jobject">
13149 <description>
13150 Holds a Java programming language object.
13151 </description>
13152 </basetype>
13153 <basetype id="jclass">
13154 <description>
13155 Holds a Java programming language class.
13156 </description>
13157 </basetype>
13158 <basetype id="jvalue">
13159 <description>
13160 Is a union of all primitive types and <code>jobject</code>. Thus, holds any Java
13161 programming language value.
13162 </description>
13163 </basetype>
13164 <basetype id="jfieldID">
13165 <description>
13166 Identifies a Java programming language field.
13167 <code>jfieldID</code>s returned by <jvmti/> functions and events may be
13168 safely stored.
13169 </description>
13170 </basetype>
13171 <basetype id="jmethodID">
13172 <description>
13173 Identifies a Java programming language method, initializer, or constructor.
13174 <code>jmethodID</code>s returned by <jvmti/> functions and events may be
13175 safely stored. However, if the class is unloaded, they become invalid
13176 and must not be used.
13177 </description>
13178 </basetype>
13179 <basetype id="JNIEnv">
13180 <description>
13181 Pointer to the JNI function table. Pointer to this (<code>JNIEnv *</code>)
13182 is a JNI environment.
13183 </description>
13184 </basetype>
13185 </basetypes>
13186
13187 <basetypes id="jvmtiTypes" label="JVM Tool Interface Base Types">
13188 <basetype id="jvmtiEnv">
13189 <description>
13190 The <jvmti/> <internallink id="environments">environment</internallink> pointer.
13191 See the <internallink id="FunctionSection">Function Section</internallink>.
13192 <code>jvmtiEnv</code> points to the
13193 <internallink id="FunctionTable">function table</internallink> pointer.
13194 </description>
13195 </basetype>
13196 <basetype id="jthread">
13197 <definition>typedef jobject jthread;</definition>
13198 <description>
13199 Subtype of <datalink id="jobject"></datalink> that holds a thread.
13200 </description>
13201 </basetype>
13202 <basetype id="jthreadGroup">
13203 <definition>typedef jobject jthreadGroup;</definition>
13204 <description>
13205 Subtype of <datalink id="jobject"></datalink> that holds a thread group.
13206 </description>
13207 </basetype>
13208 <basetype id="jlocation">
13209 <definition>typedef jlong jlocation;</definition>
13210 <description>
13211 A 64 bit value, representing a monotonically increasing
13212 executable position within a method.
13213 <code>-1</code> indicates a native method.
13214 See <functionlink id="GetJLocationFormat"></functionlink> for the format on a
13215 given VM.
13216 </description>
13217 </basetype>
13218 <basetype id="jrawMonitorID">
13219 <definition>struct _jrawMonitorID;
13220 typedef struct _jrawMonitorID *jrawMonitorID;</definition>
13221 <description>
13222 A raw monitor.
13223 </description>
13224 </basetype>
13225 <basetype id="jvmtiError">
13226 <description>
13227 Holds an error return code.
13228 See the <internallink id="ErrorSection">Error section</internallink> for possible values.
13229 <example>
13230 typedef enum {
13231 JVMTI_ERROR_NONE = 0,
13232 JVMTI_ERROR_INVALID_THREAD = 10,
13233 ...
13234 } jvmtiError;
13235 </example>
13236 </description>
13237 </basetype>
13238 <basetype id="jvmtiEvent">
13239 <description>
13240 An identifier for an event type.
13241 See the <internallink id="EventSection">Event section</internallink> for possible values.
13242 It is guaranteed that future versions of this specification will
13243 never assign zero as an event type identifier.
13244 <example>
13245 typedef enum {
13246 JVMTI_EVENT_SINGLE_STEP = 1,
13247 JVMTI_EVENT_BREAKPOINT = 2,
13248 ...
13249 } jvmtiEvent;
13250 </example>
13251 </description>
13252 </basetype>
13253 <basetype id="jvmtiEventCallbacks">
13254 <description>
13255 The callbacks used for events.
13256 <example>
13257 typedef struct {
13258 jvmtiEventVMInit VMInit;
13259 jvmtiEventVMDeath VMDeath;
13260 ...
13261 } jvmtiEventCallbacks;
13262 </example>
13263 See <internallink id="jvmtiEventCallbacks">event callbacks</internallink>
13264 for the complete structure.
13265 <p/>
13266 Where, for example, the VM initialization callback is defined:
13267 <example>
13268 typedef void (JNICALL *jvmtiEventVMInit)
13269 (jvmtiEnv *jvmti_env,
13270 JNIEnv* jni_env,
13271 jthread thread);
13272 </example>
13273 See the individual events for the callback function definition.
13274 </description>
13275 </basetype>
13276 <basetype id="jniNativeInterface">
13277 <definition>typedef struct JNINativeInterface_ jniNativeInterface;</definition>
13278 <description>
13279 Typedef for the JNI function table <code>JNINativeInterface</code>
13280 defined in the
13281 <externallink id="http://java.sun.com/javase/6/docs/guide/jni/spec/functions.html#wp23720">JNI Specification</externallink>.
13282 The JNI reference implementation defines this with an underscore.
13283 </description>
13284 </basetype>
13285 </basetypes>
13286
13287 </datasection>
13288
13289 <issuessection label="Issues">
13290 <intro id="suspendRequired" label="Resolved Issue: Suspend - Required or Automatic">
13291 JVMDI requires that the agent suspend threads before calling
13292 certain sensitive functions. JVMPI requires garbage collection to be
13293 disabled before calling certain sensitive functions.
13294 It was suggested that rather than have this requirement, that
13295 VM place itself in a suitable state before performing an
13296 operation. This makes considerable sense since each VM
13297 knows its requirements and can most easily arrange a
13298 safe state.
13299 <p/>
13300 The ability to externally suspend/resume threads will, of
13301 course, remain. The ability to enable/disable garbage collection will not.
13302 <p/>
13303 This issue is resolved--suspend will not
13304 be required. The spec has been updated to reflect this.
13305 </intro>
13306
13307 <intro id="stackSampling" label="Resolved Issue: Call Stack Sampling">
13308 There are a variety of approaches to sampling call stacks.
13309 The biggest bifurcation is between VM controlled and agent
13310 controlled.
13311 <p/>
13312 This issue is resolved--agent controlled
13313 sampling will be the approach.
13314 </intro>
13315
13316 <intro id="threadRepresentation" label="Resolved Issue: Thread Representation">
13317 JVMDI represents threads as jthread. JVMPI primarily
13318 uses JNIEnv* to represent threads.
13319 <p/>
13320 The Expert Group has chosen jthread as the representation
13321 for threads in <jvmti/>.
13322 JNIEnv* is sent by
13323 events since it is needed to JNI functions. JNIEnv, per the
13324 JNI spec, are not supposed to be used outside their thread.
13325 </intro>
13326
13327 <intro id="design" label="Resolved Issue: Method Representation">
13328 The JNI spec allows an implementation to depend on jclass/jmethodID
13329 pairs, rather than simply a jmethodID, to reference a method.
13330 JVMDI, for consistency, choose the same representation.
13331 JVMPI, however, specifies that a jmethodID alone maps to a
13332 method. Both of the Sun <tm>J2SE</tm> virtual machines (Classic and <tm>HotSpot</tm>) store
13333 pointers in jmethodIDs, and as a result, a jmethodID is sufficient.
13334 In fact, any JVM implementation that supports JVMPI must have
13335 such a representation.
13336 <jvmti/> will use jmethodID as a unique representation of a method
13337 (no jclass is used).
13338 There should be efficiency gains, particularly in
13339 functionality like stack dumping, to this representation.
13340 <p/>
13341 Note that fields were not used in JVMPI and that the access profile
13342 of fields differs from methods--for implementation efficiency
13343 reasons, a jclass/jfieldID pair will still be needed for field
13344 reference.
13345 </intro>
13346
13347 <intro id="localReferenceIssue" label="Resolved Issue: Local References">
13348 Functions return local references.
13349 </intro>
13350
13351 <intro id="frameRep" label="Resolved Issue: Representation of frames">
13352 In JVMDI, a frame ID is used to represent a frame. Problem with this
13353 is that a VM must track when a frame becomes invalid, a far better
13354 approach, and the one used in <jvmti/>, is to reference frames by depth.
13355 </intro>
13356
13357 <intro id="requiredCapabilities" label="Issue: Required Capabilities">
13358 Currently, having a required capabilities means that the functionality
13359 is optional. Capabilities are useful even for required functionality
13360 since they can inform the VM is needed set-up. Thus, there should be
13361 a set of capabilities that a conformant implementation must provide
13362 (if requested during Agent_OnLoad).
13363 </intro>
13364
13365 <intro id="taghint" label="Proposal: add tag hint function">
13366 A hint of the percentage of objects that will be tagged would
13367 help the VM pick a good implementation.
13368 </intro>
13369
13370 <intro id="moreMonitorQueries" label="Request: More Monitor Quires">
13371 How difficult or easy would be to extend the monitor_info category to include
13372 <pre>
13373 - current number of monitors
13374 - enumeration of monitors
13375 - enumeration of threads waiting on a given monitor
13376 </pre>
13377 The reason for my question is the fact that current get_monitor_info support
13378 requires the agent to specify a given thread to get the info which is probably
13379 OK in the profiling/debugging space, while in the monitoring space the agent
13380 could be watching the monitor list and then decide which thread to ask for
13381 the info. You might ask why is this important for monitoring .... I think it
13382 can aid in the detection/prediction of application contention caused by hot-locks.
13383 </intro>
13384 </issuessection>
13385
13386 <changehistory id="ChangeHistory" update="09/05/07">
13387 <intro>
13388 The <jvmti/> specification is an evolving document with major, minor,
13389 and micro version numbers.
13390 A released version of the specification is uniquely identified
13391 by its major and minor version.
13392 The functions, events, and capabilities in this specification
13393 indicate a "Since" value which is the major and minor version in
13394 which it was introduced.
13395 The version of the specification implemented by the VM can
13396 be retrieved at runtime with the <functionlink id="GetVersionNumber"/>
13397 function.
13398 </intro>
13399 <change date="14 Nov 2002">
13400 Converted to XML document.
13401 </change>
13402 <change date="14 Nov 2002">
13403 Elided heap dump functions (for now) since what was there
13404 was wrong.
13405 </change>
13406 <change date="18 Nov 2002">
13407 Added detail throughout.
13408 </change>
13409 <change date="18 Nov 2002">
13410 Changed JVMTI_THREAD_STATUS_RUNNING to JVMTI_THREAD_STATUS_RUNNABLE.
13411 </change>
13412 <change date="19 Nov 2002">
13413 Added AsyncGetStackTrace.
13414 </change>
13415 <change date="19 Nov 2002">
13416 Added jframeID return to GetStackTrace.
13417 </change>
13418 <change date="19 Nov 2002">
13419 Elided GetCurrentFrame and GetCallingFrame functions (for now) since what was there
13420 since they are redundant with GetStackTrace.
13421 </change>
13422 <change date="19 Nov 2002">
13423 Elided ClearAllBreakpoints since it has always been redundant.
13424 </change>
13425 <change date="19 Nov 2002">
13426 Added GetSystemProperties.
13427 </change>
13428 <change date="19 Nov 2002">
13429 Changed the thread local storage functions to use jthread.
13430 </change>
13431 <change date="20 Nov 2002">
13432 Added GetJLocationFormat.
13433 </change>
13434 <change date="22 Nov 2002">
13435 Added events and introductory text.
13436 </change>
13437 <change date="22 Nov 2002">
13438 Cross reference type and constant definitions.
13439 </change>
13440 <change date="24 Nov 2002">
13441 Added DTD.
13442 </change>
13443 <change date="24 Nov 2002">
13444 Added capabilities function section.
13445 </change>
13446 <change date="29 Nov 2002">
13447 Assign capabilities to each function and event.
13448 </change>
13449 <change date="29 Nov 2002">
13450 Add <internallink id="jniIntercept">JNI interception functions</internallink>.
13451 </change>
13452 <change date="30 Nov 2002">
13453 Auto generate SetEventNotificationMode capabilities.
13454 </change>
13455 <change date="30 Nov 2002">
13456 Add <eventlink id="VMObjectAlloc"></eventlink> event.
13457 </change>
13458 <change date="30 Nov 2002">
13459 Add <eventlink id="DynamicCodeGenerated"></eventlink> event.
13460 </change>
13461 <change date="30 Nov 2002">
13462 Add const to declarations.
13463 </change>
13464 <change date="30 Nov 2002">
13465 Change method exit and frame pop to send on exception.
13466 </change>
13467 <change date="1 Dec 2002">
13468 Add ForceGarbageCollection.
13469 </change>
13470 <change date="2 Dec 2002">
13471 Redo Xrun section; clarify GetStackTrace and add example;
13472 Fix width problems; use "agent" consistently.
13473 </change>
13474 <change date="8 Dec 2002">
13475 Remove previous start-up intro.
13476 Add <internallink id="environments"><jvmti/> Environments</internallink>
13477 section.
13478 </change>
13479 <change date="8 Dec 2002">
13480 Add <functionlink id="DisposeEnvironment"></functionlink>.
13481 </change>
13482 <change date="9 Dec 2002">
13483 Numerous minor updates.
13484 </change>
13485 <change date="15 Dec 2002">
13486 Add heap profiling functions added:
13487 get/set annotation, iterate live objects/heap.
13488 Add heap profiling functions place holder added:
13489 heap roots.
13490 Heap profiling event added: object free.
13491 Heap profiling event redesigned: vm object allocation.
13492 Heap profiling event placeholders added: garbage collection start/finish.
13493 Native method bind event added.
13494 </change>
13495 <change date="19 Dec 2002">
13496 Revamp suspend/resume functions.
13497 Add origin information with jvmdi tag.
13498 Misc fixes.
13499 </change>
13500 <change date="24 Dec 2002">
13501 Add semantics to types.
13502 </change>
13503 <change date="27 Dec 2002">
13504 Add local reference section.
13505 Autogenerate parameter descriptions from types.
13506 </change>
13507 <change date="28 Dec 2002">
13508 Document that RunAgentThread sends threadStart.
13509 </change>
13510 <change date="29 Dec 2002">
13511 Remove redundant local ref and dealloc warning.
13512 Convert GetRawMonitorName to allocated buffer.
13513 Add GenerateEvents.
13514 </change>
13515 <change date="30 Dec 2002">
13516 Make raw monitors a type and rename to "jrawMonitorID".
13517 </change>
13518 <change date="1 Jan 2003">
13519 Include origin information.
13520 Clean-up JVMDI issue references.
13521 Remove Deallocate warnings which are now automatically generated.
13522 </change>
13523 <change date="2 Jan 2003">
13524 Fix representation issues for jthread.
13525 </change>
13526 <change date="3 Jan 2003">
13527 Make capabilities buffered out to 64 bits - and do it automatically.
13528 </change>
13529 <change date="4 Jan 2003">
13530 Make constants which are enumeration into enum types.
13531 Parameters now of enum type.
13532 Clean-up and index type section.
13533 Replace remaining datadef entities with callback.
13534 </change>
13535 <change date="7 Jan 2003">
13536 Correct GenerateEvents description.
13537 More internal semantics work.
13538 </change>
13539 <change date="9 Jan 2003">
13540 Replace previous GetSystemProperties with two functions
13541 which use allocated information instead fixed.
13542 Add SetSystemProperty.
13543 More internal semantics work.
13544 </change>
13545 <change date="12 Jan 2003">
13546 Add varargs to end of SetEventNotificationMode.
13547 </change>
13548 <change date="20 Jan 2003">
13549 Finish fixing spec to reflect that alloc sizes are jlong.
13550 </change>
13551 <change date="22 Jan 2003">
13552 Allow NULL as RunAgentThread arg.
13553 </change>
13554 <change date="22 Jan 2003">
13555 Fixed names to standardized naming convention
13556 Removed AsyncGetStackTrace.
13557 </change>
13558 <change date="29 Jan 2003">
13559 Since we are using jthread, removed GetThread.
13560 </change>
13561 <change date="31 Jan 2003">
13562 Change GetFieldName to allow NULLs like GetMethodName.
13563 </change>
13564 <change date="29 Feb 2003" version="v40">
13565 Rewrite the introductory text, adding sections on
13566 start-up, environments and bytecode instrumentation.
13567 Change the command line arguments per EG discussions.
13568 Add an introduction to the capabilities section.
13569 Add the extension mechanism category and functions.
13570 Mark for deletion, but clarified anyhow, SuspendAllThreads.
13571 Rename IterateOverLiveObjects to IterateOverReachableObjects and
13572 change the text accordingly.
13573 Clarify IterateOverHeap.
13574 Clarify CompiledMethodLoad.
13575 Discuss prerequisite state for Calling Functions.
13576 Clarify SetAllocationHooks.
13577 Added issues ("To be resolved:") through-out.
13578 And so on...
13579 </change>
13580 <change date="6 Mar 2003" version="v41">
13581 Remove struct from the call to GetOwnedMonitorInfo.
13582 Automatically generate most error documentation, remove
13583 (rather broken) hand written error doc.
13584 Better describe capability use (empty initial set).
13585 Add min value to jint params.
13586 Remove the capability can_access_thread_local_storage.
13587 Rename error JVMTI_ERROR_NOT_IMPLEMENTED to JVMTI_ERROR_MUST_POSSESS_CAPABILITY;
13588 same for *NOT_IMPLEMENTED.
13589 Description fixes.
13590 </change>
13591 <change date="8 Mar 2003" version="v42">
13592 Rename GetClassSignature to GetClassName.
13593 Rename IterateOverClassObjects to IterateOverInstancesOfClass.
13594 Remove GetMaxStack (operand stack isn't used in <jvmti/>).
13595 Description fixes: define launch-time, remove native frame pop
13596 from PopFrame, and assorted clarifications.
13597 </change>
13598 <change date="8 Mar 2003" version="v43">
13599 Fix minor editing problem.
13600 </change>
13601 <change date="10 Mar 2003" version="v44">
13602 Add phase information.
13603 Remap (compact) event numbers.
13604 </change>
13605 <change date="11 Mar 2003" version="v45">
13606 More phase information - allow "any".
13607 Elide raw monitor queries and events.
13608 Minor description fixes.
13609 </change>
13610 <change date="12 Mar 2003" version="v46">
13611 Add GetPhase.
13612 Use "phase" through document.
13613 Elide GetRawMonitorName.
13614 Elide GetObjectMonitors.
13615 </change>
13616 <change date="12 Mar 2003" version="v47">
13617 Fixes from link, XML, and spell checking.
13618 Auto-generate the callback structure.
13619 </change>
13620 <change date="13 Mar 2003" version="v48">
13621 One character XML fix.
13622 </change>
13623 <change date="13 Mar 2003" version="v49">
13624 Change function parameter names to be consistent with
13625 event parameters (fooBarBaz becomes foo_bar_baz).
13626 </change>
13627 <change date="14 Mar 2003" version="v50">
13628 Fix broken link. Fix thread markers.
13629 </change>
13630 <change date="14 Mar 2003" version="v51">
13631 Change constants so they are under 128 to workaround
13632 compiler problems.
13633 </change>
13634 <change date="23 Mar 2003" version="v52">
13635 Overhaul capabilities. Separate GetStackTrace into
13636 GetStackTrace and GetStackFrames.
13637 </change>
13638 <change date="8 Apr 2003" version="v54">
13639 Use depth instead of jframeID to reference frames.
13640 Remove the now irrelevant GetCurrentFrame, GetCallerFrame and GetStackFrames.
13641 Remove frame arg from events.
13642 </change>
13643 <change date="9 Apr 2003" version="v55">
13644 Remove GetObjectWithAnnotation since tests show bufferred approach more efficient.
13645 Add missing annotation_count to GetObjectsWithAnnotations
13646 </change>
13647 <change date="10 Apr 2003" version="v56">
13648 Remove confusing parenthetical statement in GetObjectsWithAnnotations
13649 </change>
13650 <change date="13 Apr 2003" version="v58">
13651 Replace jclass/jmethodID representation of method with simply jmethodID;
13652 Pass JvmtiEnv* as first arg of every event; remove JNIEnv* where inappropriate.
13653 Replace can_access_frames with can_access_local_variables; remove from purely stack access.
13654 Use can_get_synthetic_attribute; fix description.
13655 Clarify that zero length arrays must be deallocated.
13656 Clarify RelinquishCapabilities.
13657 Generalize JVMTI_ERROR_VM_DEAD to JVMTI_ERROR_WRONG_PHASE.
13658 </change>
13659 <change date="27 Apr 2003" version="v59">
13660 Remove lingering indirect references to OBSOLETE_METHOD_ID.
13661 </change>
13662 <change date="4 May 2003" version="v60">
13663 Allow DestroyRawMonitor during OnLoad.
13664 </change>
13665 <change date="7 May 2003" version="v61">
13666 Added not monitor owner error return to DestroyRawMonitor.
13667 </change>
13668 <change date="13 May 2003" version="v62">
13669 Clarify semantics of raw monitors.
13670 Change flags on <code>GetThreadStatus</code>.
13671 <code>GetClassLoader</code> return NULL for the bootstrap class loader.
13672 Add <code>GetClassName</code> issue.
13673 Define local variable signature.
13674 Disallow zero in annotations array of <code>GetObjectsWithAnnotations</code>.
13675 Remove over specification in <code>GetObjectsWithAnnotations</code>.
13676 Elide <code>SetAllocationHooks</code>.
13677 Elide <code>SuspendAllThreads</code>.
13678 </change>
13679 <change date="14 May 2003" version="v63">
13680 Define the data type <code>jvmtiEventCallbacks</code>.
13681 Zero length allocations return NULL.
13682 Keep SetAllocationHooks in JVMDI, but remove from <jvmti/>.
13683 Add JVMTI_THREAD_STATUS_FLAG_INTERRUPTED.
13684 </change>
13685 <change date="15 May 2003" version="v64">
13686 Better wording, per review.
13687 </change>
13688 <change date="15 May 2003" version="v65">
13689 First Alpha.
13690 Make jmethodID and jfieldID unique, jclass not used.
13691 </change>
13692 <change date="27 May 2003" version="v66">
13693 Fix minor XSLT errors.
13694 </change>
13695 <change date="13 June 2003" version="v67">
13696 Undo making jfieldID unique (jmethodID still is).
13697 </change>
13698 <change date="17 June 2003" version="v68">
13699 Changes per June 11th Expert Group meeting --
13700 Overhaul Heap functionality: single callback,
13701 remove GetHeapRoots, add reachable iterators,
13702 and rename "annotation" to "tag".
13703 NULL thread parameter on most functions is current
13704 thread.
13705 Add timers.
13706 Remove ForceExit.
13707 Add GetEnvironmentLocalStorage.
13708 Add verbose flag and event.
13709 Add AddToBootstrapClassLoaderSearch.
13710 Update ClassFileLoadHook.
13711 </change>
13712 <change date="18 June 2003" version="v69">
13713 Clean up issues sections.
13714 Rename GetClassName back to GetClassSignature and
13715 fix description.
13716 Add generic signature to GetClassSignature,
13717 GetFieldSignature, GetMethodSignature, and
13718 GetLocalVariableTable.
13719 Elide EstimateCostOfCapabilities.
13720 Clarify that the system property functions operate
13721 on the VM view of system properties.
13722 Clarify Agent_OnLoad.
13723 Remove "const" from JNIEnv* in events.
13724 Add metadata accessors.
13725 </change>
13726 <change date="18 June 2003" version="v70">
13727 Add start_depth to GetStackTrace.
13728 Move system properties to a new category.
13729 Add GetObjectSize.
13730 Remove "X" from command line flags.
13731 XML, HTML, and spell check corrections.
13732 </change>
13733 <change date="19 June 2003" version="v71">
13734 Fix JVMTI_HEAP_ROOT_THREAD to be 6.
13735 Make each synopsis match the function name.
13736 Fix unclear wording.
13737 </change>
13738 <change date="26 June 2003" version="v72">
13739 SetThreadLocalStorage and SetEnvironmentLocalStorage should allow value
13740 to be set to NULL.
13741 NotifyFramePop, GetFrameLocationm and all the local variable operations
13742 needed to have their wording about frames fixed.
13743 Grammar and clarity need to be fixed throughout.
13744 Capitalization and puntuation need to be consistent.
13745 Need micro version number and masks for accessing major, minor, and micro.
13746 The error code lists should indicate which must be returned by
13747 an implementation.
13748 The command line properties should be visible in the properties functions.
13749 Disallow popping from the current thread.
13750 Allow implementations to return opaque frame error when they cannot pop.
13751 The NativeMethodBind event should be sent during any phase.
13752 The DynamicCodeGenerated event should be sent during any phase.
13753 The following functions should be allowed to operate before VMInit:
13754 Set/GetEnvironmentLocalStorage
13755 GetMethodDeclaringClass
13756 GetClassSignature
13757 GetClassModifiers
13758 IsInterface
13759 IsArrayClass
13760 GetMethodName
13761 GetMethodModifiers
13762 GetMaxLocals
13763 GetArgumentsSize
13764 GetLineNumberTable
13765 GetMethodLocation
13766 IsMethodNative
13767 IsMethodSynthetic.
13768 Other changes (to XSL):
13769 Argument description should show asterisk after not before pointers.
13770 NotifyFramePop, GetFrameLocationm and all the local variable operations
13771 should hsve the NO_MORE_FRAMES error added.
13772 Not alive threads should have a different error return than invalid thread.
13773 </change>
13774 <change date="7 July 2003" version="v73">
13775 VerboseOutput event was missing message parameter.
13776 Minor fix-ups.
13777 </change>
13778 <change date="14 July 2003" version="v74">
13779 Technical Publications Department corrections.
13780 Allow thread and environment local storage to be set to NULL.
13781 </change>
13782 <change date="23 July 2003" version="v75">
13783 Use new Agent_OnLoad rather than overloaded JVM_OnLoad.
13784 Add JNICALL to callbacks (XSL).
13785 Document JNICALL requirement for both events and callbacks (XSL).
13786 Restrict RedefineClasses to methods and attributes.
13787 Elide the VerboseOutput event.
13788 VMObjectAlloc: restrict when event is sent and remove method parameter.
13789 Finish loose ends from Tech Pubs edit.
13790 </change>
13791 <change date="24 July 2003" version="v76">
13792 Change ClassFileLoadHook event to send the class instead of a boolean of redefine.
13793 </change>
13794 <change date="24 July 2003" version="v77">
13795 XML fixes.
13796 Minor text clarifications and corrections.
13797 </change>
13798 <change date="24 July 2003" version="v78">
13799 Remove GetExceptionHandlerTable and GetThrownExceptions from <jvmti/>.
13800 Clarify that stack frames are JVM Spec frames.
13801 Split can_get_source_info into can_get_source_file_name, can_get_line_numbers,
13802 and can_get_source_debug_extension.
13803 PopFrame cannot have a native calling method.
13804 Removed incorrect statement in GetClassloaderClasses
13805 (see http://java.sun.com/docs/books/vmspec/2nd-edition/html/ConstantPool.doc.html#79383).
13806 </change>
13807 <change date="24 July 2003" version="v79">
13808 XML and text fixes.
13809 Move stack frame description into Stack Frame category.
13810 </change>
13811 <change date="26 July 2003" version="v80">
13812 Allow NULL (means bootstrap loader) for GetClassloaderClasses.
13813 Add new heap reference kinds for references from classes.
13814 Add timer information struct and query functions.
13815 Add AvailableProcessors.
13816 Rename GetOtherThreadCpuTime to GetThreadCpuTime.
13817 Explicitly add JVMTI_ERROR_INVALID_THREAD and JVMTI_ERROR_THREAD_NOT_ALIVE
13818 to SetEventNotification mode.
13819 Add initial thread to the VM_INIT event.
13820 Remove platform assumptions from AddToBootstrapClassLoaderSearch.
13821 </change>
13822 <change date="26 July 2003" version="v81">
13823 Grammar and clarity changes per review.
13824 </change>
13825 <change date="27 July 2003" version="v82">
13826 More grammar and clarity changes per review.
13827 Add Agent_OnUnload.
13828 </change>
13829 <change date="28 July 2003" version="v83">
13830 Change return type of Agent_OnUnload to void.
13831 </change>
13832 <change date="28 July 2003" version="v84">
13833 Rename JVMTI_REFERENCE_ARRAY to JVMTI_REFERENCE_ARRAY_ELEMENT.
13834 </change>
13835 <change date="28 July 2003" version="v85">
13836 Steal java.lang.Runtime.availableProcessors() wording for
13837 AvailableProcessors().
13838 Guarantee that zero will never be an event ID.
13839 Remove some issues which are no longer issues.
13840 Per review, rename and more completely document the timer
13841 information functions.
13842 </change>
13843 <change date="29 July 2003" version="v86">
13844 Non-spec visible change to XML controlled implementation:
13845 SetThreadLocalStorage must run in VM mode.
13846 </change>
13847 <change date="5 August 2003" version="0.1.87">
13848 Add GetErrorName.
13849 Add varargs warning to jvmtiExtensionEvent.
13850 Remove "const" on the jvmtiEnv* of jvmtiExtensionEvent.
13851 Remove unused can_get_exception_info capability.
13852 Pass jvmtiEnv* and JNIEnv* to the jvmtiStartFunction.
13853 Fix jvmtiExtensionFunctionInfo.func declared type.
13854 Extension function returns error code.
13855 Use new version numbering.
13856 </change>
13857 <change date="5 August 2003" version="0.2.88">
13858 Remove the ClassUnload event.
13859 </change>
13860 <change date="8 August 2003" version="0.2.89">
13861 Heap reference iterator callbacks return an enum that
13862 allows outgoing object references to be ignored.
13863 Allow JNIEnv as a param type to extension events/functions.
13864 </change>
13865 <change date="15 August 2003" version="0.2.90">
13866 Fix a typo.
13867 </change>
13868 <change date="2 September 2003" version="0.2.91">
13869 Remove all metadata functions: GetClassMetadata,
13870 GetFieldMetadata, and GetMethodMetadata.
13871 </change>
13872 <change date="1 October 2003" version="0.2.92">
13873 Mark the functions Allocate. Deallocate, RawMonitor*,
13874 SetEnvironmentLocalStorage, and GetEnvironmentLocalStorage
13875 as safe for use in heap callbacks and GC events.
13876 </change>
13877 <change date="24 November 2003" version="0.2.93">
13878 Add pass through opaque user data pointer to heap iterate
13879 functions and callbacks.
13880 In the CompiledMethodUnload event, send the code address.
13881 Add GarbageCollectionOccurred event.
13882 Add constant pool reference kind.
13883 Mark the functions CreateRawMonitor and DestroyRawMonitor
13884 as safe for use in heap callbacks and GC events.
13885 Clarify: VMDeath, GetCurrentThreadCpuTimerInfo,
13886 GetThreadCpuTimerInfo, IterateOverReachableObjects,
13887 IterateOverObjectsReachableFromObject, GetTime and
13888 JVMTI_ERROR_NULL_POINTER.
13889 Add missing errors to: GenerateEvents and
13890 AddToBootstrapClassLoaderSearch.
13891 Fix description of ClassFileLoadHook name parameter.
13892 In heap callbacks and GC/ObjectFree events, specify
13893 that only explicitly allowed functions can be called.
13894 Allow GetCurrentThreadCpuTimerInfo, GetCurrentThreadCpuTime,
13895 GetTimerInfo, and GetTime during callback.
13896 Allow calling SetTag/GetTag during the onload phase.
13897 SetEventNotificationMode, add: error attempted inappropriate
13898 thread level control.
13899 Remove jvmtiExceptionHandlerEntry.
13900 Fix handling of native methods on the stack --
13901 location_ptr param of GetFrameLocation, remove
13902 JVMTI_ERROR_OPAQUE_FRAME from GetFrameLocation,
13903 jvmtiFrameInfo.location, and jlocation.
13904 Remove typo (from JVMPI) implying that the MonitorWaited
13905 event is sent on sleep.
13906 </change>
13907 <change date="25 November 2003" version="0.2.94">
13908 Clarifications and typos.
13909 </change>
13910 <change date="3 December 2003" version="0.2.95">
13911 Allow NULL user_data in heap iterators.
13912 </change>
13913 <change date="28 January 2004" version="0.2.97">
13914 Add GetThreadState, deprecate GetThreadStatus.
13915 </change>
13916 <change date="29 January 2004" version="0.2.98">
13917 INVALID_SLOT and TYPE_MISMATCH errors should be optional.
13918 </change>
13919 <change date="12 February 2004" version="0.2.102">
13920 Remove MonitorContendedExit.
13921 Added JNIEnv parameter to VMObjectAlloc.
13922 Clarified definition of class_tag and referrer_index
13923 parameters to heap callbacks.
13924 </change>
13925 <change date="16 Febuary 2004" version="0.2.103">
13926 Document JAVA_TOOL_OPTIONS.
13927 </change>
13928 <change date="17 Febuary 2004" version="0.2.105">
13929 Divide start phase into primordial and start.
13930 Add VMStart event
13931 Change phase associations of functions and events.
13932 </change>
13933 <change date="18 Febuary 2004" version="0.3.6">
13934 Elide deprecated GetThreadStatus.
13935 Bump minor version, subtract 100 from micro version
13936 </change>
13937 <change date="18 Febuary 2004" version="0.3.7">
13938 Document that timer nanosecond values are unsigned.
13939 Clarify text having to do with native methods.
13940 </change>
13941 <change date="19 Febuary 2004" version="0.3.8">
13942 Fix typos.
13943 Remove elided deprecated GetThreadStatus.
13944 </change>
13945 <change date="23 Febuary 2004" version="0.3.9">
13946 Require NotifyFramePop to act on suspended threads.
13947 </change>
13948 <change date="24 Febuary 2004" version="0.3.10">
13949 Add capabilities
13950 (<internallink id="jvmtiCapabilities.can_redefine_any_class"
13951 ><code>can_redefine_any_class</code></internallink>
13952 and
13953 <internallink id="jvmtiCapabilities.can_generate_all_class_hook_events"
13954 ><code>can_generate_all_class_hook_events</code></internallink>)
13955 and an error (<errorlink id="JVMTI_ERROR_UNMODIFIABLE_CLASS"></errorlink>)
13956 which allow some classes to be unmodifiable.
13957 </change>
13958 <change date="28 Febuary 2004" version="0.3.11">
13959 Add JVMTI_ERROR_MUST_POSSESS_CAPABILITY to SetEventNotificationMode.
13960 </change>
13961 <change date="8 March 2004" version="0.3.12">
13962 Clarified CompiledMethodUnload so that it is clear the event
13963 may be posted after the class has been unloaded.
13964 </change>
13965 <change date="5 March 2004" version="0.3.13">
13966 Change the size parameter of VMObjectAlloc to jlong to match GetObjectSize.
13967 </change>
13968 <change date="13 March 2004" version="0.3.14">
13969 Added guideline for the use of the JNI FindClass function in event
13970 callback functions.
13971 </change>
13972 <change date="15 March 2004" version="0.3.15">
13973 Add GetAllStackTraces and GetThreadListStackTraces.
13974 </change>
13975 <change date="19 March 2004" version="0.3.16">
13976 ClassLoad and ClassPrepare events can be posted during start phase.
13977 </change>
13978 <change date="25 March 2004" version="0.3.17">
13979 Add JVMTI_ERROR_NATIVE_METHOD to GetLineNumberTable, GetLocalVariableTable,
13980 GetMaxLocals, GetArgumentsSize, GetMethodLocation, GetBytecodes.
13981 </change>
13982 <change date="29 March 2004" version="0.3.18">
13983 Return the timer kind in the timer information structure.
13984 </change>
13985 <change date="31 March 2004" version="0.3.19">
13986 Spec clarifications:
13987 JVMTI_THREAD_STATE_IN_NATIVE might not include JNI or <jvmti/>.
13988 ForceGarbageCollection does not run finalizers.
13989 The context of the specification is the Java platform.
13990 Warn about early instrumentation.
13991 </change>
13992 <change date="1 April 2004" version="0.3.20">
13993 Refinements to the above clarifications and
13994 Clarify that an error returned by Agent_OnLoad terminates the VM.
13995 </change>
13996 <change date="1 April 2004" version="0.3.21">
13997 Array class creation does not generate a class load event.
13998 </change>
13999 <change date="7 April 2004" version="0.3.22">
14000 Align thread state hierarchy more closely with java.lang.Thread.State.
14001 </change>
14002 <change date="12 April 2004" version="0.3.23">
14003 Clarify the documentation of thread state.
14004 </change>
14005 <change date="19 April 2004" version="0.3.24">
14006 Remove GarbageCollectionOccurred event -- can be done by agent.
14007 </change>
14008 <change date="22 April 2004" version="0.3.25">
14009 Define "command-line option".
14010 </change>
14011 <change date="29 April 2004" version="0.3.26">
14012 Describe the intended use of bytecode instrumentation.
14013 Fix description of extension event first parameter.
14014 </change>
14015 <change date="30 April 2004" version="0.3.27">
14016 Clarification and typos.
14017 </change>
14018 <change date="18 May 2004" version="0.3.28">
14019 Remove DataDumpRequest event.
14020 </change>
14021 <change date="18 May 2004" version="0.3.29">
14022 Clarify RawMonitorWait with zero timeout.
14023 Clarify thread state after RunAgentThread.
14024 </change>
14025 <change date="24 May 2004" version="0.3.30">
14026 Clean-up: fix bad/old links, etc.
14027 </change>
14028 <change date="30 May 2004" version="0.3.31">
14029 Clarifications including:
14030 All character strings are modified UTF-8.
14031 Agent thread visibiity.
14032 Meaning of obsolete method version.
14033 Thread invoking heap callbacks,
14034 </change>
14035 <change date="1 June 2004" version="1.0.32">
14036 Bump major.minor version numbers to "1.0".
14037 </change>
14038 <change date="2 June 2004" version="1.0.33">
14039 Clarify interaction between ForceGarbageCollection
14040 and ObjectFree.
14041 </change>
14042 <change date="6 June 2004" version="1.0.34">
14043 Restrict AddToBootstrapClassLoaderSearch and
14044 SetSystemProperty to the OnLoad phase only.
14045 </change>
14046 <change date="11 June 2004" version="1.0.35">
14047 Fix typo in SetTag.
14048 </change>
14049 <change date="18 June 2004" version="1.0.36">
14050 Fix trademarks.
14051 Add missing parameter in example GetThreadState usage.
14052 </change>
14053 <change date="4 August 2004" version="1.0.37">
14054 Copyright updates.
14055 </change>
14056 <change date="5 November 2004" version="1.0.38">
14057 Add missing function table layout.
14058 Add missing description of C++ member function format of functions.
14059 Clarify that name in CFLH can be NULL.
14060 Released as part of <tm>J2SE</tm> 5.0.
14061 </change>
14062 <change date="24 April 2005" version="1.1.47">
14063 Bump major.minor version numbers to "1.1".
14064 Add ForceEarlyReturn* functions.
14065 Add GetOwnedMonitorStackDepthInfo function.
14066 Add GetCurrentThread function.
14067 Add "since" version marker.
14068 Add AddToSystemClassLoaderSearch.
14069 Allow AddToBootstrapClassLoaderSearch be used in live phase.
14070 Fix historic rubbish in the descriptions of the heap_object_callback
14071 parameter of IterateOverHeap and IterateOverInstancesOfClass functions;
14072 disallow NULL for this parameter.
14073 Clarify, correct and make consistent: wording about current thread,
14074 opaque frames and insufficient number of frames in PopFrame.
14075 Consistently use "current frame" rather than "topmost".
14076 Clarify the JVMTI_ERROR_TYPE_MISMATCH errors in GetLocal* and SetLocal*
14077 by making them compatible with those in ForceEarlyReturn*.
14078 Many other clarifications and wording clean ups.
14079 </change>
14080 <change date="25 April 2005" version="1.1.48">
14081 Add GetConstantPool.
14082 Switch references to the first edition of the VM Spec, to the seconds edition.
14083 </change>
14084 <change date="26 April 2005" version="1.1.49">
14085 Clarify minor/major version order in GetConstantPool.
14086 </change>
14087 <change date="26 April 2005" version="1.1.50">
14088 Add SetNativeMethodPrefix and SetNativeMethodPrefixes.
14089 Reassign GetOwnedMonitorStackDepthInfo to position 153.
14090 Break out Class Loader Search in its own documentation category.
14091 Deal with overly long lines in XML source.
14092 </change>
14093 <change date="29 April 2005" version="1.1.51">
14094 Allow agents be started in the live phase.
14095 Added paragraph about deploying agents.
14096 </change>
14097 <change date="30 April 2005" version="1.1.52">
14098 Add specification description to SetNativeMethodPrefix(es).
14099 Better define the conditions on GetConstantPool.
14100 </change>
14101 <change date="30 April 2005" version="1.1.53">
14102 Break out the GetClassVersionNumber function from GetConstantPool.
14103 Clean-up the references to the VM Spec.
14104 </change>
14105 <change date="1 May 2005" version="1.1.54">
14106 Allow SetNativeMethodPrefix(es) in any phase.
14107 Add clarifications about the impact of redefinition on GetConstantPool.
14108 </change>
14109 <change date="2 May 2005" version="1.1.56">
14110 Various clarifications to SetNativeMethodPrefix(es).
14111 </change>
14112 <change date="2 May 2005" version="1.1.57">
14113 Add missing performance warning to the method entry event.
14114 </change>
14115 <change date="5 May 2005" version="1.1.58">
14116 Remove internal JVMDI support.
14117 </change>
14118 <change date="8 May 2005" version="1.1.59">
14119 Add <functionlink id="RetransformClasses"/>.
14120 Revamp the bytecode instrumentation documentation.
14121 Change <functionlink id="IsMethodObsolete"/> to no longer
14122 require the can_redefine_classes capability.
14123 </change>
14124 <change date="11 May 2005" version="1.1.63">
14125 Clarifications for retransformation.
14126 </change>
14127 <change date="11 May 2005" version="1.1.64">
14128 Clarifications for retransformation, per review.
14129 Lock "retransformation (in)capable" at class load enable time.
14130 </change>
14131 <change date="4 June 2005" version="1.1.67">
14132 Add new heap functionity which supports reporting primitive values,
14133 allows setting the referrer tag, and has more powerful filtering:
14134 FollowReferences, IterateThroughHeap, and their associated
14135 callbacks, structs, enums, and constants.
14136 </change>
14137 <change date="4 June 2005" version="1.1.68">
14138 Clarification.
14139 </change>
14140 <change date="6 June 2005" version="1.1.69">
14141 FollowReferences, IterateThroughHeap: Put callbacks in a struct;
14142 Add missing error codes; reduce bits in the visit control flags.
14143 </change>
14144 <change date="14 June 2005" version="1.1.70">
14145 More on new heap functionity: spec clean-up per review.
14146 </change>
14147 <change date="15 June 2005" version="1.1.71">
14148 More on new heap functionity: Rename old heap section to Heap (1.0).
14149 </change>
14150 <change date="21 June 2005" version="1.1.72">
14151 Fix typos.
14152 </change>
14153 <change date="27 June 2005" version="1.1.73">
14154 Make referrer info structure a union.
14155 </change>
14156 <change date="9 September 2005" version="1.1.74">
14157 In new heap functions:
14158 Add missing superclass reference kind.
14159 Use a single scheme for computing field indexes.
14160 Remove outdated references to struct based referrer info.
14161 </change>
14162 <change date="12 September 2005" version="1.1.75">
14163 Don't callback during FollowReferences on frivolous java.lang.Object superclass.
14164 </change>
14165 <change date="13 September 2005" version="1.1.76">
14166 In string primitive callback, length now Unicode length.
14167 In array and string primitive callbacks, value now "const".
14168 Note possible compiler impacts on setting JNI function table.
14169 </change>
14170 <change date="13 September 2005" version="1.1.77">
14171 GetClassVersionNumbers() and GetConstantPool() should return
14172 error on array or primitive class.
14173 </change>
14174 <change date="14 September 2005" version="1.1.78">
14175 Grammar fixes.
14176 </change>
14177 <change date="26 September 2005" version="1.1.79">
14178 Add IsModifiableClass query.
14179 </change>
14180 <change date="9 February 2006" version="1.1.81">
14181 Add referrer_class_tag parameter to jvmtiHeapReferenceCallback.
14182 </change>
14183 <change date="13 February 2006" version="1.1.82">
14184 Doc fixes: update can_redefine_any_class to include retransform.
14185 Clarify that exception events cover all Throwables.
14186 In GetStackTrace, no test is done for start_depth too big if start_depth is zero,
14187 Clarify fields reported in Primitive Field Callback -- static vs instance.
14188 Repair confusing names of heap types, including callback names.
14189 Require consistent usage of stack depth in the face of thread launch methods.
14190 Note incompatibility of <jvmti/> memory management with other systems.
14191 </change>
14192 <change date="14 February 2006" version="1.1.85">
14193 Fix typos and missing renames.
14194 </change>
14195 <change date="13 March 2006" version="1.1.86">
14196 Clarify that jmethodIDs and jfieldIDs can be saved.
14197 Clarify that Iterate Over Instances Of Class includes subclasses.
14198 </change>
14199 <change date="14 March 2006" version="1.1.87">
14200 Better phrasing.
14201 </change>
14202 <change date="16 March 2006" version="1.1.88">
14203 Match the referrer_index for static fields in Object Reference Callback
14204 with the Reference Implementation (and all other known implementations);
14205 that is, make it match the definition for instance fields.
14206 In GetThreadListStackTraces, add JVMTI_ERROR_INVALID_THREAD to cover
14207 an invalid thread in the list; and specify that not started threads
14208 return empty stacks.
14209 </change>
14210 <change date="17 March 2006" version="1.1.89">
14211 Typo.
14212 </change>
14213 <change date="25 March 2006" version="1.1.90">
14214 Typo.
14215 </change>
14216 <change date="6 April 2006" version="1.1.91">
14217 Remove restrictions on AddToBootstrapClassLoaderSearch and
14218 AddToSystemClassLoaderSearch.
14219 </change>
14220 <change date="1 May 2006" version="1.1.93">
14221 Changed spec to return -1 for monitor stack depth for the
14222 implementation which can not determine stack depth.
14223 </change>
14224 <change date="3 May 2006" version="1.1.94">
14225 Corrections for readability and accuracy courtesy of Alan Pratt of IBM.
14226 List the object relationships reported in FollowReferences.
14227 </change>
14228 <change date="5 May 2006" version="1.1.95">
14229 Clarify the object relationships reported in FollowReferences.
14230 </change>
14231 <change date="28 June 2006" version="1.1.98">
14232 Clarify DisposeEnvironment; add warning.
14233 Fix typos in SetLocalXXX "retrieve" => "set".
14234 Clarify that native method prefixes must remain set while used.
14235 Clarify that exactly one Agent_OnXXX is called per agent.
14236 Clarify that library loading is independent from start-up.
14237 Remove ambiguous reference to Agent_OnLoad in the Agent_OnUnload spec.
14238 </change>
14239 <change date="31 July 2006" version="1.1.99">
14240 Clarify the interaction between functions and exceptions.
14241 Clarify and give examples of field indices.
14242 Remove confusing "That is" sentence from MonitorWait and MonitorWaited events.
14243 Update links to point to Java 6.
14244 </change>
14245 <change date="6 August 2006" version="1.1.102">
14246 Add ResourceExhaustedEvent.
14247 </change>
14248 </changehistory>
14249
14250 </specification>
14251 <!-- Keep this comment at the end of the file
14252 Local variables:
14253 mode: sgml
14254 sgml-omittag:t
14255 sgml-shorttag:t
14256 sgml-namecase-general:t
14257 sgml-general-insert-case:lower
14258 sgml-minimize-attributes:nil
14259 sgml-always-quote-attributes:t
14260 sgml-indent-step:2
14261 sgml-indent-data:t
14262 sgml-parent-document:nil
14263 sgml-exposed-tags:nil
14264 sgml-local-catalogs:nil
14265 sgml-local-ecat-files:nil
14266 End:
14267 -->