Mercurial > hg > graal-compiler
comparison src/share/vm/prims/jvmtiRedefineClasses.cpp @ 0:a61af66fc99e jdk7-b24
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author | duke |
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date | Sat, 01 Dec 2007 00:00:00 +0000 |
parents | |
children | 0af8b0718fc9 ea20d7ce26b0 |
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-1:000000000000 | 0:a61af66fc99e |
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1 /* | |
2 * Copyright 2003-2007 Sun Microsystems, Inc. All Rights Reserved. | |
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. | |
4 * | |
5 * This code is free software; you can redistribute it and/or modify it | |
6 * under the terms of the GNU General Public License version 2 only, as | |
7 * published by the Free Software Foundation. | |
8 * | |
9 * This code is distributed in the hope that it will be useful, but WITHOUT | |
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
12 * version 2 for more details (a copy is included in the LICENSE file that | |
13 * accompanied this code). | |
14 * | |
15 * You should have received a copy of the GNU General Public License version | |
16 * 2 along with this work; if not, write to the Free Software Foundation, | |
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. | |
18 * | |
19 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, | |
20 * CA 95054 USA or visit www.sun.com if you need additional information or | |
21 * have any questions. | |
22 * | |
23 */ | |
24 | |
25 # include "incls/_precompiled.incl" | |
26 # include "incls/_jvmtiRedefineClasses.cpp.incl" | |
27 | |
28 | |
29 objArrayOop VM_RedefineClasses::_old_methods = NULL; | |
30 objArrayOop VM_RedefineClasses::_new_methods = NULL; | |
31 methodOop* VM_RedefineClasses::_matching_old_methods = NULL; | |
32 methodOop* VM_RedefineClasses::_matching_new_methods = NULL; | |
33 methodOop* VM_RedefineClasses::_deleted_methods = NULL; | |
34 methodOop* VM_RedefineClasses::_added_methods = NULL; | |
35 int VM_RedefineClasses::_matching_methods_length = 0; | |
36 int VM_RedefineClasses::_deleted_methods_length = 0; | |
37 int VM_RedefineClasses::_added_methods_length = 0; | |
38 klassOop VM_RedefineClasses::_the_class_oop = NULL; | |
39 | |
40 | |
41 VM_RedefineClasses::VM_RedefineClasses(jint class_count, | |
42 const jvmtiClassDefinition *class_defs, | |
43 JvmtiClassLoadKind class_load_kind) { | |
44 _class_count = class_count; | |
45 _class_defs = class_defs; | |
46 _class_load_kind = class_load_kind; | |
47 _res = JVMTI_ERROR_NONE; | |
48 } | |
49 | |
50 bool VM_RedefineClasses::doit_prologue() { | |
51 if (_class_count == 0) { | |
52 _res = JVMTI_ERROR_NONE; | |
53 return false; | |
54 } | |
55 if (_class_defs == NULL) { | |
56 _res = JVMTI_ERROR_NULL_POINTER; | |
57 return false; | |
58 } | |
59 for (int i = 0; i < _class_count; i++) { | |
60 if (_class_defs[i].klass == NULL) { | |
61 _res = JVMTI_ERROR_INVALID_CLASS; | |
62 return false; | |
63 } | |
64 if (_class_defs[i].class_byte_count == 0) { | |
65 _res = JVMTI_ERROR_INVALID_CLASS_FORMAT; | |
66 return false; | |
67 } | |
68 if (_class_defs[i].class_bytes == NULL) { | |
69 _res = JVMTI_ERROR_NULL_POINTER; | |
70 return false; | |
71 } | |
72 } | |
73 | |
74 // Start timer after all the sanity checks; not quite accurate, but | |
75 // better than adding a bunch of stop() calls. | |
76 RC_TIMER_START(_timer_vm_op_prologue); | |
77 | |
78 // We first load new class versions in the prologue, because somewhere down the | |
79 // call chain it is required that the current thread is a Java thread. | |
80 _res = load_new_class_versions(Thread::current()); | |
81 if (_res != JVMTI_ERROR_NONE) { | |
82 // Free os::malloc allocated memory in load_new_class_version. | |
83 os::free(_scratch_classes); | |
84 RC_TIMER_STOP(_timer_vm_op_prologue); | |
85 return false; | |
86 } | |
87 | |
88 RC_TIMER_STOP(_timer_vm_op_prologue); | |
89 return true; | |
90 } | |
91 | |
92 void VM_RedefineClasses::doit() { | |
93 Thread *thread = Thread::current(); | |
94 | |
95 if (UseSharedSpaces) { | |
96 // Sharing is enabled so we remap the shared readonly space to | |
97 // shared readwrite, private just in case we need to redefine | |
98 // a shared class. We do the remap during the doit() phase of | |
99 // the safepoint to be safer. | |
100 if (!CompactingPermGenGen::remap_shared_readonly_as_readwrite()) { | |
101 RC_TRACE_WITH_THREAD(0x00000001, thread, | |
102 ("failed to remap shared readonly space to readwrite, private")); | |
103 _res = JVMTI_ERROR_INTERNAL; | |
104 return; | |
105 } | |
106 } | |
107 | |
108 for (int i = 0; i < _class_count; i++) { | |
109 redefine_single_class(_class_defs[i].klass, _scratch_classes[i], thread); | |
110 } | |
111 // Disable any dependent concurrent compilations | |
112 SystemDictionary::notice_modification(); | |
113 | |
114 // Set flag indicating that some invariants are no longer true. | |
115 // See jvmtiExport.hpp for detailed explanation. | |
116 JvmtiExport::set_has_redefined_a_class(); | |
117 | |
118 #ifdef ASSERT | |
119 SystemDictionary::classes_do(check_class, thread); | |
120 #endif | |
121 } | |
122 | |
123 void VM_RedefineClasses::doit_epilogue() { | |
124 // Free os::malloc allocated memory. | |
125 // The memory allocated in redefine will be free'ed in next VM operation. | |
126 os::free(_scratch_classes); | |
127 | |
128 if (RC_TRACE_ENABLED(0x00000004)) { | |
129 // Used to have separate timers for "doit" and "all", but the timer | |
130 // overhead skewed the measurements. | |
131 jlong doit_time = _timer_rsc_phase1.milliseconds() + | |
132 _timer_rsc_phase2.milliseconds(); | |
133 jlong all_time = _timer_vm_op_prologue.milliseconds() + doit_time; | |
134 | |
135 RC_TRACE(0x00000004, ("vm_op: all=" UINT64_FORMAT | |
136 " prologue=" UINT64_FORMAT " doit=" UINT64_FORMAT, all_time, | |
137 _timer_vm_op_prologue.milliseconds(), doit_time)); | |
138 RC_TRACE(0x00000004, | |
139 ("redefine_single_class: phase1=" UINT64_FORMAT " phase2=" UINT64_FORMAT, | |
140 _timer_rsc_phase1.milliseconds(), _timer_rsc_phase2.milliseconds())); | |
141 } | |
142 } | |
143 | |
144 bool VM_RedefineClasses::is_modifiable_class(oop klass_mirror) { | |
145 // classes for primitives cannot be redefined | |
146 if (java_lang_Class::is_primitive(klass_mirror)) { | |
147 return false; | |
148 } | |
149 klassOop the_class_oop = java_lang_Class::as_klassOop(klass_mirror); | |
150 // classes for arrays cannot be redefined | |
151 if (the_class_oop == NULL || !Klass::cast(the_class_oop)->oop_is_instance()) { | |
152 return false; | |
153 } | |
154 return true; | |
155 } | |
156 | |
157 // Append the current entry at scratch_i in scratch_cp to *merge_cp_p | |
158 // where the end of *merge_cp_p is specified by *merge_cp_length_p. For | |
159 // direct CP entries, there is just the current entry to append. For | |
160 // indirect and double-indirect CP entries, there are zero or more | |
161 // referenced CP entries along with the current entry to append. | |
162 // Indirect and double-indirect CP entries are handled by recursive | |
163 // calls to append_entry() as needed. The referenced CP entries are | |
164 // always appended to *merge_cp_p before the referee CP entry. These | |
165 // referenced CP entries may already exist in *merge_cp_p in which case | |
166 // there is nothing extra to append and only the current entry is | |
167 // appended. | |
168 void VM_RedefineClasses::append_entry(constantPoolHandle scratch_cp, | |
169 int scratch_i, constantPoolHandle *merge_cp_p, int *merge_cp_length_p, | |
170 TRAPS) { | |
171 | |
172 // append is different depending on entry tag type | |
173 switch (scratch_cp->tag_at(scratch_i).value()) { | |
174 | |
175 // The old verifier is implemented outside the VM. It loads classes, | |
176 // but does not resolve constant pool entries directly so we never | |
177 // see Class entries here with the old verifier. Similarly the old | |
178 // verifier does not like Class entries in the input constant pool. | |
179 // The split-verifier is implemented in the VM so it can optionally | |
180 // and directly resolve constant pool entries to load classes. The | |
181 // split-verifier can accept either Class entries or UnresolvedClass | |
182 // entries in the input constant pool. We revert the appended copy | |
183 // back to UnresolvedClass so that either verifier will be happy | |
184 // with the constant pool entry. | |
185 case JVM_CONSTANT_Class: | |
186 { | |
187 // revert the copy to JVM_CONSTANT_UnresolvedClass | |
188 (*merge_cp_p)->unresolved_klass_at_put(*merge_cp_length_p, | |
189 scratch_cp->klass_name_at(scratch_i)); | |
190 | |
191 if (scratch_i != *merge_cp_length_p) { | |
192 // The new entry in *merge_cp_p is at a different index than | |
193 // the new entry in scratch_cp so we need to map the index values. | |
194 map_index(scratch_cp, scratch_i, *merge_cp_length_p); | |
195 } | |
196 (*merge_cp_length_p)++; | |
197 } break; | |
198 | |
199 // these are direct CP entries so they can be directly appended, | |
200 // but double and long take two constant pool entries | |
201 case JVM_CONSTANT_Double: // fall through | |
202 case JVM_CONSTANT_Long: | |
203 { | |
204 scratch_cp->copy_entry_to(scratch_i, *merge_cp_p, *merge_cp_length_p, | |
205 THREAD); | |
206 | |
207 if (scratch_i != *merge_cp_length_p) { | |
208 // The new entry in *merge_cp_p is at a different index than | |
209 // the new entry in scratch_cp so we need to map the index values. | |
210 map_index(scratch_cp, scratch_i, *merge_cp_length_p); | |
211 } | |
212 (*merge_cp_length_p) += 2; | |
213 } break; | |
214 | |
215 // these are direct CP entries so they can be directly appended | |
216 case JVM_CONSTANT_Float: // fall through | |
217 case JVM_CONSTANT_Integer: // fall through | |
218 case JVM_CONSTANT_Utf8: // fall through | |
219 | |
220 // This was an indirect CP entry, but it has been changed into | |
221 // an interned string so this entry can be directly appended. | |
222 case JVM_CONSTANT_String: // fall through | |
223 | |
224 // These were indirect CP entries, but they have been changed into | |
225 // symbolOops so these entries can be directly appended. | |
226 case JVM_CONSTANT_UnresolvedClass: // fall through | |
227 case JVM_CONSTANT_UnresolvedString: | |
228 { | |
229 scratch_cp->copy_entry_to(scratch_i, *merge_cp_p, *merge_cp_length_p, | |
230 THREAD); | |
231 | |
232 if (scratch_i != *merge_cp_length_p) { | |
233 // The new entry in *merge_cp_p is at a different index than | |
234 // the new entry in scratch_cp so we need to map the index values. | |
235 map_index(scratch_cp, scratch_i, *merge_cp_length_p); | |
236 } | |
237 (*merge_cp_length_p)++; | |
238 } break; | |
239 | |
240 // this is an indirect CP entry so it needs special handling | |
241 case JVM_CONSTANT_NameAndType: | |
242 { | |
243 int name_ref_i = scratch_cp->name_ref_index_at(scratch_i); | |
244 int new_name_ref_i = 0; | |
245 bool match = (name_ref_i < *merge_cp_length_p) && | |
246 scratch_cp->compare_entry_to(name_ref_i, *merge_cp_p, name_ref_i, | |
247 THREAD); | |
248 if (!match) { | |
249 // forward reference in *merge_cp_p or not a direct match | |
250 | |
251 int found_i = scratch_cp->find_matching_entry(name_ref_i, *merge_cp_p, | |
252 THREAD); | |
253 if (found_i != 0) { | |
254 guarantee(found_i != name_ref_i, | |
255 "compare_entry_to() and find_matching_entry() do not agree"); | |
256 | |
257 // Found a matching entry somewhere else in *merge_cp_p so | |
258 // just need a mapping entry. | |
259 new_name_ref_i = found_i; | |
260 map_index(scratch_cp, name_ref_i, found_i); | |
261 } else { | |
262 // no match found so we have to append this entry to *merge_cp_p | |
263 append_entry(scratch_cp, name_ref_i, merge_cp_p, merge_cp_length_p, | |
264 THREAD); | |
265 // The above call to append_entry() can only append one entry | |
266 // so the post call query of *merge_cp_length_p is only for | |
267 // the sake of consistency. | |
268 new_name_ref_i = *merge_cp_length_p - 1; | |
269 } | |
270 } | |
271 | |
272 int signature_ref_i = scratch_cp->signature_ref_index_at(scratch_i); | |
273 int new_signature_ref_i = 0; | |
274 match = (signature_ref_i < *merge_cp_length_p) && | |
275 scratch_cp->compare_entry_to(signature_ref_i, *merge_cp_p, | |
276 signature_ref_i, THREAD); | |
277 if (!match) { | |
278 // forward reference in *merge_cp_p or not a direct match | |
279 | |
280 int found_i = scratch_cp->find_matching_entry(signature_ref_i, | |
281 *merge_cp_p, THREAD); | |
282 if (found_i != 0) { | |
283 guarantee(found_i != signature_ref_i, | |
284 "compare_entry_to() and find_matching_entry() do not agree"); | |
285 | |
286 // Found a matching entry somewhere else in *merge_cp_p so | |
287 // just need a mapping entry. | |
288 new_signature_ref_i = found_i; | |
289 map_index(scratch_cp, signature_ref_i, found_i); | |
290 } else { | |
291 // no match found so we have to append this entry to *merge_cp_p | |
292 append_entry(scratch_cp, signature_ref_i, merge_cp_p, | |
293 merge_cp_length_p, THREAD); | |
294 // The above call to append_entry() can only append one entry | |
295 // so the post call query of *merge_cp_length_p is only for | |
296 // the sake of consistency. | |
297 new_signature_ref_i = *merge_cp_length_p - 1; | |
298 } | |
299 } | |
300 | |
301 // If the referenced entries already exist in *merge_cp_p, then | |
302 // both new_name_ref_i and new_signature_ref_i will both be 0. | |
303 // In that case, all we are appending is the current entry. | |
304 if (new_name_ref_i == 0) { | |
305 new_name_ref_i = name_ref_i; | |
306 } else { | |
307 RC_TRACE(0x00080000, | |
308 ("NameAndType entry@%d name_ref_index change: %d to %d", | |
309 *merge_cp_length_p, name_ref_i, new_name_ref_i)); | |
310 } | |
311 if (new_signature_ref_i == 0) { | |
312 new_signature_ref_i = signature_ref_i; | |
313 } else { | |
314 RC_TRACE(0x00080000, | |
315 ("NameAndType entry@%d signature_ref_index change: %d to %d", | |
316 *merge_cp_length_p, signature_ref_i, new_signature_ref_i)); | |
317 } | |
318 | |
319 (*merge_cp_p)->name_and_type_at_put(*merge_cp_length_p, | |
320 new_name_ref_i, new_signature_ref_i); | |
321 if (scratch_i != *merge_cp_length_p) { | |
322 // The new entry in *merge_cp_p is at a different index than | |
323 // the new entry in scratch_cp so we need to map the index values. | |
324 map_index(scratch_cp, scratch_i, *merge_cp_length_p); | |
325 } | |
326 (*merge_cp_length_p)++; | |
327 } break; | |
328 | |
329 // this is a double-indirect CP entry so it needs special handling | |
330 case JVM_CONSTANT_Fieldref: // fall through | |
331 case JVM_CONSTANT_InterfaceMethodref: // fall through | |
332 case JVM_CONSTANT_Methodref: | |
333 { | |
334 int klass_ref_i = scratch_cp->uncached_klass_ref_index_at(scratch_i); | |
335 int new_klass_ref_i = 0; | |
336 bool match = (klass_ref_i < *merge_cp_length_p) && | |
337 scratch_cp->compare_entry_to(klass_ref_i, *merge_cp_p, klass_ref_i, | |
338 THREAD); | |
339 if (!match) { | |
340 // forward reference in *merge_cp_p or not a direct match | |
341 | |
342 int found_i = scratch_cp->find_matching_entry(klass_ref_i, *merge_cp_p, | |
343 THREAD); | |
344 if (found_i != 0) { | |
345 guarantee(found_i != klass_ref_i, | |
346 "compare_entry_to() and find_matching_entry() do not agree"); | |
347 | |
348 // Found a matching entry somewhere else in *merge_cp_p so | |
349 // just need a mapping entry. | |
350 new_klass_ref_i = found_i; | |
351 map_index(scratch_cp, klass_ref_i, found_i); | |
352 } else { | |
353 // no match found so we have to append this entry to *merge_cp_p | |
354 append_entry(scratch_cp, klass_ref_i, merge_cp_p, merge_cp_length_p, | |
355 THREAD); | |
356 // The above call to append_entry() can only append one entry | |
357 // so the post call query of *merge_cp_length_p is only for | |
358 // the sake of consistency. Without the optimization where we | |
359 // use JVM_CONSTANT_UnresolvedClass, then up to two entries | |
360 // could be appended. | |
361 new_klass_ref_i = *merge_cp_length_p - 1; | |
362 } | |
363 } | |
364 | |
365 int name_and_type_ref_i = | |
366 scratch_cp->uncached_name_and_type_ref_index_at(scratch_i); | |
367 int new_name_and_type_ref_i = 0; | |
368 match = (name_and_type_ref_i < *merge_cp_length_p) && | |
369 scratch_cp->compare_entry_to(name_and_type_ref_i, *merge_cp_p, | |
370 name_and_type_ref_i, THREAD); | |
371 if (!match) { | |
372 // forward reference in *merge_cp_p or not a direct match | |
373 | |
374 int found_i = scratch_cp->find_matching_entry(name_and_type_ref_i, | |
375 *merge_cp_p, THREAD); | |
376 if (found_i != 0) { | |
377 guarantee(found_i != name_and_type_ref_i, | |
378 "compare_entry_to() and find_matching_entry() do not agree"); | |
379 | |
380 // Found a matching entry somewhere else in *merge_cp_p so | |
381 // just need a mapping entry. | |
382 new_name_and_type_ref_i = found_i; | |
383 map_index(scratch_cp, name_and_type_ref_i, found_i); | |
384 } else { | |
385 // no match found so we have to append this entry to *merge_cp_p | |
386 append_entry(scratch_cp, name_and_type_ref_i, merge_cp_p, | |
387 merge_cp_length_p, THREAD); | |
388 // The above call to append_entry() can append more than | |
389 // one entry so the post call query of *merge_cp_length_p | |
390 // is required in order to get the right index for the | |
391 // JVM_CONSTANT_NameAndType entry. | |
392 new_name_and_type_ref_i = *merge_cp_length_p - 1; | |
393 } | |
394 } | |
395 | |
396 // If the referenced entries already exist in *merge_cp_p, then | |
397 // both new_klass_ref_i and new_name_and_type_ref_i will both be | |
398 // 0. In that case, all we are appending is the current entry. | |
399 if (new_klass_ref_i == 0) { | |
400 new_klass_ref_i = klass_ref_i; | |
401 } | |
402 if (new_name_and_type_ref_i == 0) { | |
403 new_name_and_type_ref_i = name_and_type_ref_i; | |
404 } | |
405 | |
406 const char *entry_name; | |
407 switch (scratch_cp->tag_at(scratch_i).value()) { | |
408 case JVM_CONSTANT_Fieldref: | |
409 entry_name = "Fieldref"; | |
410 (*merge_cp_p)->field_at_put(*merge_cp_length_p, new_klass_ref_i, | |
411 new_name_and_type_ref_i); | |
412 break; | |
413 case JVM_CONSTANT_InterfaceMethodref: | |
414 entry_name = "IFMethodref"; | |
415 (*merge_cp_p)->interface_method_at_put(*merge_cp_length_p, | |
416 new_klass_ref_i, new_name_and_type_ref_i); | |
417 break; | |
418 case JVM_CONSTANT_Methodref: | |
419 entry_name = "Methodref"; | |
420 (*merge_cp_p)->method_at_put(*merge_cp_length_p, new_klass_ref_i, | |
421 new_name_and_type_ref_i); | |
422 break; | |
423 default: | |
424 guarantee(false, "bad switch"); | |
425 break; | |
426 } | |
427 | |
428 if (klass_ref_i != new_klass_ref_i) { | |
429 RC_TRACE(0x00080000, ("%s entry@%d class_index changed: %d to %d", | |
430 entry_name, *merge_cp_length_p, klass_ref_i, new_klass_ref_i)); | |
431 } | |
432 if (name_and_type_ref_i != new_name_and_type_ref_i) { | |
433 RC_TRACE(0x00080000, | |
434 ("%s entry@%d name_and_type_index changed: %d to %d", | |
435 entry_name, *merge_cp_length_p, name_and_type_ref_i, | |
436 new_name_and_type_ref_i)); | |
437 } | |
438 | |
439 if (scratch_i != *merge_cp_length_p) { | |
440 // The new entry in *merge_cp_p is at a different index than | |
441 // the new entry in scratch_cp so we need to map the index values. | |
442 map_index(scratch_cp, scratch_i, *merge_cp_length_p); | |
443 } | |
444 (*merge_cp_length_p)++; | |
445 } break; | |
446 | |
447 // At this stage, Class or UnresolvedClass could be here, but not | |
448 // ClassIndex | |
449 case JVM_CONSTANT_ClassIndex: // fall through | |
450 | |
451 // Invalid is used as the tag for the second constant pool entry | |
452 // occupied by JVM_CONSTANT_Double or JVM_CONSTANT_Long. It should | |
453 // not be seen by itself. | |
454 case JVM_CONSTANT_Invalid: // fall through | |
455 | |
456 // At this stage, String or UnresolvedString could be here, but not | |
457 // StringIndex | |
458 case JVM_CONSTANT_StringIndex: // fall through | |
459 | |
460 // At this stage JVM_CONSTANT_UnresolvedClassInError should not be | |
461 // here | |
462 case JVM_CONSTANT_UnresolvedClassInError: // fall through | |
463 | |
464 default: | |
465 { | |
466 // leave a breadcrumb | |
467 jbyte bad_value = scratch_cp->tag_at(scratch_i).value(); | |
468 ShouldNotReachHere(); | |
469 } break; | |
470 } // end switch tag value | |
471 } // end append_entry() | |
472 | |
473 | |
474 void VM_RedefineClasses::swap_all_method_annotations(int i, int j, instanceKlassHandle scratch_class) { | |
475 typeArrayOop save; | |
476 | |
477 save = scratch_class->get_method_annotations_of(i); | |
478 scratch_class->set_method_annotations_of(i, scratch_class->get_method_annotations_of(j)); | |
479 scratch_class->set_method_annotations_of(j, save); | |
480 | |
481 save = scratch_class->get_method_parameter_annotations_of(i); | |
482 scratch_class->set_method_parameter_annotations_of(i, scratch_class->get_method_parameter_annotations_of(j)); | |
483 scratch_class->set_method_parameter_annotations_of(j, save); | |
484 | |
485 save = scratch_class->get_method_default_annotations_of(i); | |
486 scratch_class->set_method_default_annotations_of(i, scratch_class->get_method_default_annotations_of(j)); | |
487 scratch_class->set_method_default_annotations_of(j, save); | |
488 } | |
489 | |
490 | |
491 jvmtiError VM_RedefineClasses::compare_and_normalize_class_versions( | |
492 instanceKlassHandle the_class, | |
493 instanceKlassHandle scratch_class) { | |
494 int i; | |
495 | |
496 // Check superclasses, or rather their names, since superclasses themselves can be | |
497 // requested to replace. | |
498 // Check for NULL superclass first since this might be java.lang.Object | |
499 if (the_class->super() != scratch_class->super() && | |
500 (the_class->super() == NULL || scratch_class->super() == NULL || | |
501 Klass::cast(the_class->super())->name() != | |
502 Klass::cast(scratch_class->super())->name())) { | |
503 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_HIERARCHY_CHANGED; | |
504 } | |
505 | |
506 // Check if the number, names and order of directly implemented interfaces are the same. | |
507 // I think in principle we should just check if the sets of names of directly implemented | |
508 // interfaces are the same, i.e. the order of declaration (which, however, if changed in the | |
509 // .java file, also changes in .class file) should not matter. However, comparing sets is | |
510 // technically a bit more difficult, and, more importantly, I am not sure at present that the | |
511 // order of interfaces does not matter on the implementation level, i.e. that the VM does not | |
512 // rely on it somewhere. | |
513 objArrayOop k_interfaces = the_class->local_interfaces(); | |
514 objArrayOop k_new_interfaces = scratch_class->local_interfaces(); | |
515 int n_intfs = k_interfaces->length(); | |
516 if (n_intfs != k_new_interfaces->length()) { | |
517 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_HIERARCHY_CHANGED; | |
518 } | |
519 for (i = 0; i < n_intfs; i++) { | |
520 if (Klass::cast((klassOop) k_interfaces->obj_at(i))->name() != | |
521 Klass::cast((klassOop) k_new_interfaces->obj_at(i))->name()) { | |
522 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_HIERARCHY_CHANGED; | |
523 } | |
524 } | |
525 | |
526 // Check whether class is in the error init state. | |
527 if (the_class->is_in_error_state()) { | |
528 // TBD #5057930: special error code is needed in 1.6 | |
529 return JVMTI_ERROR_INVALID_CLASS; | |
530 } | |
531 | |
532 // Check whether class modifiers are the same. | |
533 jushort old_flags = (jushort) the_class->access_flags().get_flags(); | |
534 jushort new_flags = (jushort) scratch_class->access_flags().get_flags(); | |
535 if (old_flags != new_flags) { | |
536 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_CLASS_MODIFIERS_CHANGED; | |
537 } | |
538 | |
539 // Check if the number, names, types and order of fields declared in these classes | |
540 // are the same. | |
541 typeArrayOop k_old_fields = the_class->fields(); | |
542 typeArrayOop k_new_fields = scratch_class->fields(); | |
543 int n_fields = k_old_fields->length(); | |
544 if (n_fields != k_new_fields->length()) { | |
545 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_SCHEMA_CHANGED; | |
546 } | |
547 | |
548 for (i = 0; i < n_fields; i += instanceKlass::next_offset) { | |
549 // access | |
550 old_flags = k_old_fields->ushort_at(i + instanceKlass::access_flags_offset); | |
551 new_flags = k_new_fields->ushort_at(i + instanceKlass::access_flags_offset); | |
552 if ((old_flags ^ new_flags) & JVM_RECOGNIZED_FIELD_MODIFIERS) { | |
553 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_SCHEMA_CHANGED; | |
554 } | |
555 // offset | |
556 if (k_old_fields->short_at(i + instanceKlass::low_offset) != | |
557 k_new_fields->short_at(i + instanceKlass::low_offset) || | |
558 k_old_fields->short_at(i + instanceKlass::high_offset) != | |
559 k_new_fields->short_at(i + instanceKlass::high_offset)) { | |
560 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_SCHEMA_CHANGED; | |
561 } | |
562 // name and signature | |
563 jshort name_index = k_old_fields->short_at(i + instanceKlass::name_index_offset); | |
564 jshort sig_index = k_old_fields->short_at(i +instanceKlass::signature_index_offset); | |
565 symbolOop name_sym1 = the_class->constants()->symbol_at(name_index); | |
566 symbolOop sig_sym1 = the_class->constants()->symbol_at(sig_index); | |
567 name_index = k_new_fields->short_at(i + instanceKlass::name_index_offset); | |
568 sig_index = k_new_fields->short_at(i + instanceKlass::signature_index_offset); | |
569 symbolOop name_sym2 = scratch_class->constants()->symbol_at(name_index); | |
570 symbolOop sig_sym2 = scratch_class->constants()->symbol_at(sig_index); | |
571 if (name_sym1 != name_sym2 || sig_sym1 != sig_sym2) { | |
572 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_SCHEMA_CHANGED; | |
573 } | |
574 } | |
575 | |
576 // Do a parallel walk through the old and new methods. Detect | |
577 // cases where they match (exist in both), have been added in | |
578 // the new methods, or have been deleted (exist only in the | |
579 // old methods). The class file parser places methods in order | |
580 // by method name, but does not order overloaded methods by | |
581 // signature. In order to determine what fate befell the methods, | |
582 // this code places the overloaded new methods that have matching | |
583 // old methods in the same order as the old methods and places | |
584 // new overloaded methods at the end of overloaded methods of | |
585 // that name. The code for this order normalization is adapted | |
586 // from the algorithm used in instanceKlass::find_method(). | |
587 // Since we are swapping out of order entries as we find them, | |
588 // we only have to search forward through the overloaded methods. | |
589 // Methods which are added and have the same name as an existing | |
590 // method (but different signature) will be put at the end of | |
591 // the methods with that name, and the name mismatch code will | |
592 // handle them. | |
593 objArrayHandle k_old_methods(the_class->methods()); | |
594 objArrayHandle k_new_methods(scratch_class->methods()); | |
595 int n_old_methods = k_old_methods->length(); | |
596 int n_new_methods = k_new_methods->length(); | |
597 | |
598 int ni = 0; | |
599 int oi = 0; | |
600 while (true) { | |
601 methodOop k_old_method; | |
602 methodOop k_new_method; | |
603 enum { matched, added, deleted, undetermined } method_was = undetermined; | |
604 | |
605 if (oi >= n_old_methods) { | |
606 if (ni >= n_new_methods) { | |
607 break; // we've looked at everything, done | |
608 } | |
609 // New method at the end | |
610 k_new_method = (methodOop) k_new_methods->obj_at(ni); | |
611 method_was = added; | |
612 } else if (ni >= n_new_methods) { | |
613 // Old method, at the end, is deleted | |
614 k_old_method = (methodOop) k_old_methods->obj_at(oi); | |
615 method_was = deleted; | |
616 } else { | |
617 // There are more methods in both the old and new lists | |
618 k_old_method = (methodOop) k_old_methods->obj_at(oi); | |
619 k_new_method = (methodOop) k_new_methods->obj_at(ni); | |
620 if (k_old_method->name() != k_new_method->name()) { | |
621 // Methods are sorted by method name, so a mismatch means added | |
622 // or deleted | |
623 if (k_old_method->name()->fast_compare(k_new_method->name()) > 0) { | |
624 method_was = added; | |
625 } else { | |
626 method_was = deleted; | |
627 } | |
628 } else if (k_old_method->signature() == k_new_method->signature()) { | |
629 // Both the name and signature match | |
630 method_was = matched; | |
631 } else { | |
632 // The name matches, but the signature doesn't, which means we have to | |
633 // search forward through the new overloaded methods. | |
634 int nj; // outside the loop for post-loop check | |
635 for (nj = ni + 1; nj < n_new_methods; nj++) { | |
636 methodOop m = (methodOop)k_new_methods->obj_at(nj); | |
637 if (k_old_method->name() != m->name()) { | |
638 // reached another method name so no more overloaded methods | |
639 method_was = deleted; | |
640 break; | |
641 } | |
642 if (k_old_method->signature() == m->signature()) { | |
643 // found a match so swap the methods | |
644 k_new_methods->obj_at_put(ni, m); | |
645 k_new_methods->obj_at_put(nj, k_new_method); | |
646 k_new_method = m; | |
647 method_was = matched; | |
648 break; | |
649 } | |
650 } | |
651 | |
652 if (nj >= n_new_methods) { | |
653 // reached the end without a match; so method was deleted | |
654 method_was = deleted; | |
655 } | |
656 } | |
657 } | |
658 | |
659 switch (method_was) { | |
660 case matched: | |
661 // methods match, be sure modifiers do too | |
662 old_flags = (jushort) k_old_method->access_flags().get_flags(); | |
663 new_flags = (jushort) k_new_method->access_flags().get_flags(); | |
664 if ((old_flags ^ new_flags) & ~(JVM_ACC_NATIVE)) { | |
665 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_MODIFIERS_CHANGED; | |
666 } | |
667 { | |
668 u2 new_num = k_new_method->method_idnum(); | |
669 u2 old_num = k_old_method->method_idnum(); | |
670 if (new_num != old_num) { | |
671 methodOop idnum_owner = scratch_class->method_with_idnum(old_num); | |
672 if (idnum_owner != NULL) { | |
673 // There is already a method assigned this idnum -- switch them | |
674 idnum_owner->set_method_idnum(new_num); | |
675 } | |
676 k_new_method->set_method_idnum(old_num); | |
677 swap_all_method_annotations(old_num, new_num, scratch_class); | |
678 } | |
679 } | |
680 RC_TRACE(0x00008000, ("Method matched: new: %s [%d] == old: %s [%d]", | |
681 k_new_method->name_and_sig_as_C_string(), ni, | |
682 k_old_method->name_and_sig_as_C_string(), oi)); | |
683 // advance to next pair of methods | |
684 ++oi; | |
685 ++ni; | |
686 break; | |
687 case added: | |
688 // method added, see if it is OK | |
689 new_flags = (jushort) k_new_method->access_flags().get_flags(); | |
690 if ((new_flags & JVM_ACC_PRIVATE) == 0 | |
691 // hack: private should be treated as final, but alas | |
692 || (new_flags & (JVM_ACC_FINAL|JVM_ACC_STATIC)) == 0 | |
693 ) { | |
694 // new methods must be private | |
695 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_ADDED; | |
696 } | |
697 { | |
698 u2 num = the_class->next_method_idnum(); | |
699 if (num == constMethodOopDesc::UNSET_IDNUM) { | |
700 // cannot add any more methods | |
701 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_ADDED; | |
702 } | |
703 u2 new_num = k_new_method->method_idnum(); | |
704 methodOop idnum_owner = scratch_class->method_with_idnum(num); | |
705 if (idnum_owner != NULL) { | |
706 // There is already a method assigned this idnum -- switch them | |
707 idnum_owner->set_method_idnum(new_num); | |
708 } | |
709 k_new_method->set_method_idnum(num); | |
710 swap_all_method_annotations(new_num, num, scratch_class); | |
711 } | |
712 RC_TRACE(0x00008000, ("Method added: new: %s [%d]", | |
713 k_new_method->name_and_sig_as_C_string(), ni)); | |
714 ++ni; // advance to next new method | |
715 break; | |
716 case deleted: | |
717 // method deleted, see if it is OK | |
718 old_flags = (jushort) k_old_method->access_flags().get_flags(); | |
719 if ((old_flags & JVM_ACC_PRIVATE) == 0 | |
720 // hack: private should be treated as final, but alas | |
721 || (old_flags & (JVM_ACC_FINAL|JVM_ACC_STATIC)) == 0 | |
722 ) { | |
723 // deleted methods must be private | |
724 return JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_DELETED; | |
725 } | |
726 RC_TRACE(0x00008000, ("Method deleted: old: %s [%d]", | |
727 k_old_method->name_and_sig_as_C_string(), oi)); | |
728 ++oi; // advance to next old method | |
729 break; | |
730 default: | |
731 ShouldNotReachHere(); | |
732 } | |
733 } | |
734 | |
735 return JVMTI_ERROR_NONE; | |
736 } | |
737 | |
738 | |
739 // Find new constant pool index value for old constant pool index value | |
740 // by seaching the index map. Returns zero (0) if there is no mapped | |
741 // value for the old constant pool index. | |
742 int VM_RedefineClasses::find_new_index(int old_index) { | |
743 if (_index_map_count == 0) { | |
744 // map is empty so nothing can be found | |
745 return 0; | |
746 } | |
747 | |
748 if (old_index < 1 || old_index >= _index_map_p->length()) { | |
749 // The old_index is out of range so it is not mapped. This should | |
750 // not happen in regular constant pool merging use, but it can | |
751 // happen if a corrupt annotation is processed. | |
752 return 0; | |
753 } | |
754 | |
755 int value = _index_map_p->at(old_index); | |
756 if (value == -1) { | |
757 // the old_index is not mapped | |
758 return 0; | |
759 } | |
760 | |
761 return value; | |
762 } // end find_new_index() | |
763 | |
764 | |
765 // Returns true if the current mismatch is due to a resolved/unresolved | |
766 // class pair. Otherwise, returns false. | |
767 bool VM_RedefineClasses::is_unresolved_class_mismatch(constantPoolHandle cp1, | |
768 int index1, constantPoolHandle cp2, int index2) { | |
769 | |
770 jbyte t1 = cp1->tag_at(index1).value(); | |
771 if (t1 != JVM_CONSTANT_Class && t1 != JVM_CONSTANT_UnresolvedClass) { | |
772 return false; // wrong entry type; not our special case | |
773 } | |
774 | |
775 jbyte t2 = cp2->tag_at(index2).value(); | |
776 if (t2 != JVM_CONSTANT_Class && t2 != JVM_CONSTANT_UnresolvedClass) { | |
777 return false; // wrong entry type; not our special case | |
778 } | |
779 | |
780 if (t1 == t2) { | |
781 return false; // not a mismatch; not our special case | |
782 } | |
783 | |
784 char *s1 = cp1->klass_name_at(index1)->as_C_string(); | |
785 char *s2 = cp2->klass_name_at(index2)->as_C_string(); | |
786 if (strcmp(s1, s2) != 0) { | |
787 return false; // strings don't match; not our special case | |
788 } | |
789 | |
790 return true; // made it through the gauntlet; this is our special case | |
791 } // end is_unresolved_class_mismatch() | |
792 | |
793 | |
794 // Returns true if the current mismatch is due to a resolved/unresolved | |
795 // string pair. Otherwise, returns false. | |
796 bool VM_RedefineClasses::is_unresolved_string_mismatch(constantPoolHandle cp1, | |
797 int index1, constantPoolHandle cp2, int index2) { | |
798 | |
799 jbyte t1 = cp1->tag_at(index1).value(); | |
800 if (t1 != JVM_CONSTANT_String && t1 != JVM_CONSTANT_UnresolvedString) { | |
801 return false; // wrong entry type; not our special case | |
802 } | |
803 | |
804 jbyte t2 = cp2->tag_at(index2).value(); | |
805 if (t2 != JVM_CONSTANT_String && t2 != JVM_CONSTANT_UnresolvedString) { | |
806 return false; // wrong entry type; not our special case | |
807 } | |
808 | |
809 if (t1 == t2) { | |
810 return false; // not a mismatch; not our special case | |
811 } | |
812 | |
813 char *s1 = cp1->string_at_noresolve(index1); | |
814 char *s2 = cp2->string_at_noresolve(index2); | |
815 if (strcmp(s1, s2) != 0) { | |
816 return false; // strings don't match; not our special case | |
817 } | |
818 | |
819 return true; // made it through the gauntlet; this is our special case | |
820 } // end is_unresolved_string_mismatch() | |
821 | |
822 | |
823 jvmtiError VM_RedefineClasses::load_new_class_versions(TRAPS) { | |
824 // For consistency allocate memory using os::malloc wrapper. | |
825 _scratch_classes = (instanceKlassHandle *) | |
826 os::malloc(sizeof(instanceKlassHandle) * _class_count); | |
827 if (_scratch_classes == NULL) { | |
828 return JVMTI_ERROR_OUT_OF_MEMORY; | |
829 } | |
830 | |
831 ResourceMark rm(THREAD); | |
832 | |
833 JvmtiThreadState *state = JvmtiThreadState::state_for(JavaThread::current()); | |
834 for (int i = 0; i < _class_count; i++) { | |
835 oop mirror = JNIHandles::resolve_non_null(_class_defs[i].klass); | |
836 // classes for primitives cannot be redefined | |
837 if (!is_modifiable_class(mirror)) { | |
838 return JVMTI_ERROR_UNMODIFIABLE_CLASS; | |
839 } | |
840 klassOop the_class_oop = java_lang_Class::as_klassOop(mirror); | |
841 instanceKlassHandle the_class = instanceKlassHandle(THREAD, the_class_oop); | |
842 symbolHandle the_class_sym = symbolHandle(THREAD, the_class->name()); | |
843 | |
844 // RC_TRACE_WITH_THREAD macro has an embedded ResourceMark | |
845 RC_TRACE_WITH_THREAD(0x00000001, THREAD, | |
846 ("loading name=%s (avail_mem=" UINT64_FORMAT "K)", | |
847 the_class->external_name(), os::available_memory() >> 10)); | |
848 | |
849 ClassFileStream st((u1*) _class_defs[i].class_bytes, | |
850 _class_defs[i].class_byte_count, (char *)"__VM_RedefineClasses__"); | |
851 | |
852 // Parse the stream. | |
853 Handle the_class_loader(THREAD, the_class->class_loader()); | |
854 Handle protection_domain(THREAD, the_class->protection_domain()); | |
855 // Set redefined class handle in JvmtiThreadState class. | |
856 // This redefined class is sent to agent event handler for class file | |
857 // load hook event. | |
858 state->set_class_being_redefined(&the_class, _class_load_kind); | |
859 | |
860 klassOop k = SystemDictionary::parse_stream(the_class_sym, | |
861 the_class_loader, | |
862 protection_domain, | |
863 &st, | |
864 THREAD); | |
865 // Clear class_being_redefined just to be sure. | |
866 state->clear_class_being_redefined(); | |
867 | |
868 // TODO: if this is retransform, and nothing changed we can skip it | |
869 | |
870 instanceKlassHandle scratch_class (THREAD, k); | |
871 | |
872 if (HAS_PENDING_EXCEPTION) { | |
873 symbolOop ex_name = PENDING_EXCEPTION->klass()->klass_part()->name(); | |
874 // RC_TRACE_WITH_THREAD macro has an embedded ResourceMark | |
875 RC_TRACE_WITH_THREAD(0x00000002, THREAD, ("parse_stream exception: '%s'", | |
876 ex_name->as_C_string())); | |
877 CLEAR_PENDING_EXCEPTION; | |
878 | |
879 if (ex_name == vmSymbols::java_lang_UnsupportedClassVersionError()) { | |
880 return JVMTI_ERROR_UNSUPPORTED_VERSION; | |
881 } else if (ex_name == vmSymbols::java_lang_ClassFormatError()) { | |
882 return JVMTI_ERROR_INVALID_CLASS_FORMAT; | |
883 } else if (ex_name == vmSymbols::java_lang_ClassCircularityError()) { | |
884 return JVMTI_ERROR_CIRCULAR_CLASS_DEFINITION; | |
885 } else if (ex_name == vmSymbols::java_lang_NoClassDefFoundError()) { | |
886 // The message will be "XXX (wrong name: YYY)" | |
887 return JVMTI_ERROR_NAMES_DONT_MATCH; | |
888 } else if (ex_name == vmSymbols::java_lang_OutOfMemoryError()) { | |
889 return JVMTI_ERROR_OUT_OF_MEMORY; | |
890 } else { // Just in case more exceptions can be thrown.. | |
891 return JVMTI_ERROR_FAILS_VERIFICATION; | |
892 } | |
893 } | |
894 | |
895 // Ensure class is linked before redefine | |
896 if (!the_class->is_linked()) { | |
897 the_class->link_class(THREAD); | |
898 if (HAS_PENDING_EXCEPTION) { | |
899 symbolOop ex_name = PENDING_EXCEPTION->klass()->klass_part()->name(); | |
900 // RC_TRACE_WITH_THREAD macro has an embedded ResourceMark | |
901 RC_TRACE_WITH_THREAD(0x00000002, THREAD, ("link_class exception: '%s'", | |
902 ex_name->as_C_string())); | |
903 CLEAR_PENDING_EXCEPTION; | |
904 if (ex_name == vmSymbols::java_lang_OutOfMemoryError()) { | |
905 return JVMTI_ERROR_OUT_OF_MEMORY; | |
906 } else { | |
907 return JVMTI_ERROR_INTERNAL; | |
908 } | |
909 } | |
910 } | |
911 | |
912 // Do the validity checks in compare_and_normalize_class_versions() | |
913 // before verifying the byte codes. By doing these checks first, we | |
914 // limit the number of functions that require redirection from | |
915 // the_class to scratch_class. In particular, we don't have to | |
916 // modify JNI GetSuperclass() and thus won't change its performance. | |
917 jvmtiError res = compare_and_normalize_class_versions(the_class, | |
918 scratch_class); | |
919 if (res != JVMTI_ERROR_NONE) { | |
920 return res; | |
921 } | |
922 | |
923 // verify what the caller passed us | |
924 { | |
925 // The bug 6214132 caused the verification to fail. | |
926 // Information about the_class and scratch_class is temporarily | |
927 // recorded into jvmtiThreadState. This data is used to redirect | |
928 // the_class to scratch_class in the JVM_* functions called by the | |
929 // verifier. Please, refer to jvmtiThreadState.hpp for the detailed | |
930 // description. | |
931 RedefineVerifyMark rvm(&the_class, &scratch_class, state); | |
932 Verifier::verify( | |
933 scratch_class, Verifier::ThrowException, THREAD); | |
934 } | |
935 | |
936 if (HAS_PENDING_EXCEPTION) { | |
937 symbolOop ex_name = PENDING_EXCEPTION->klass()->klass_part()->name(); | |
938 // RC_TRACE_WITH_THREAD macro has an embedded ResourceMark | |
939 RC_TRACE_WITH_THREAD(0x00000002, THREAD, | |
940 ("verify_byte_codes exception: '%s'", ex_name->as_C_string())); | |
941 CLEAR_PENDING_EXCEPTION; | |
942 if (ex_name == vmSymbols::java_lang_OutOfMemoryError()) { | |
943 return JVMTI_ERROR_OUT_OF_MEMORY; | |
944 } else { | |
945 // tell the caller the bytecodes are bad | |
946 return JVMTI_ERROR_FAILS_VERIFICATION; | |
947 } | |
948 } | |
949 | |
950 res = merge_cp_and_rewrite(the_class, scratch_class, THREAD); | |
951 if (res != JVMTI_ERROR_NONE) { | |
952 return res; | |
953 } | |
954 | |
955 if (VerifyMergedCPBytecodes) { | |
956 // verify what we have done during constant pool merging | |
957 { | |
958 RedefineVerifyMark rvm(&the_class, &scratch_class, state); | |
959 Verifier::verify(scratch_class, Verifier::ThrowException, THREAD); | |
960 } | |
961 | |
962 if (HAS_PENDING_EXCEPTION) { | |
963 symbolOop ex_name = PENDING_EXCEPTION->klass()->klass_part()->name(); | |
964 // RC_TRACE_WITH_THREAD macro has an embedded ResourceMark | |
965 RC_TRACE_WITH_THREAD(0x00000002, THREAD, | |
966 ("verify_byte_codes post merge-CP exception: '%s'", | |
967 ex_name->as_C_string())); | |
968 CLEAR_PENDING_EXCEPTION; | |
969 if (ex_name == vmSymbols::java_lang_OutOfMemoryError()) { | |
970 return JVMTI_ERROR_OUT_OF_MEMORY; | |
971 } else { | |
972 // tell the caller that constant pool merging screwed up | |
973 return JVMTI_ERROR_INTERNAL; | |
974 } | |
975 } | |
976 } | |
977 | |
978 Rewriter::rewrite(scratch_class, THREAD); | |
979 if (HAS_PENDING_EXCEPTION) { | |
980 symbolOop ex_name = PENDING_EXCEPTION->klass()->klass_part()->name(); | |
981 CLEAR_PENDING_EXCEPTION; | |
982 if (ex_name == vmSymbols::java_lang_OutOfMemoryError()) { | |
983 return JVMTI_ERROR_OUT_OF_MEMORY; | |
984 } else { | |
985 return JVMTI_ERROR_INTERNAL; | |
986 } | |
987 } | |
988 | |
989 _scratch_classes[i] = scratch_class; | |
990 | |
991 // RC_TRACE_WITH_THREAD macro has an embedded ResourceMark | |
992 RC_TRACE_WITH_THREAD(0x00000001, THREAD, | |
993 ("loaded name=%s (avail_mem=" UINT64_FORMAT "K)", | |
994 the_class->external_name(), os::available_memory() >> 10)); | |
995 } | |
996 | |
997 return JVMTI_ERROR_NONE; | |
998 } | |
999 | |
1000 | |
1001 // Map old_index to new_index as needed. scratch_cp is only needed | |
1002 // for RC_TRACE() calls. | |
1003 void VM_RedefineClasses::map_index(constantPoolHandle scratch_cp, | |
1004 int old_index, int new_index) { | |
1005 if (find_new_index(old_index) != 0) { | |
1006 // old_index is already mapped | |
1007 return; | |
1008 } | |
1009 | |
1010 if (old_index == new_index) { | |
1011 // no mapping is needed | |
1012 return; | |
1013 } | |
1014 | |
1015 _index_map_p->at_put(old_index, new_index); | |
1016 _index_map_count++; | |
1017 | |
1018 RC_TRACE(0x00040000, ("mapped tag %d at index %d to %d", | |
1019 scratch_cp->tag_at(old_index).value(), old_index, new_index)); | |
1020 } // end map_index() | |
1021 | |
1022 | |
1023 // Merge old_cp and scratch_cp and return the results of the merge via | |
1024 // merge_cp_p. The number of entries in *merge_cp_p is returned via | |
1025 // merge_cp_length_p. The entries in old_cp occupy the same locations | |
1026 // in *merge_cp_p. Also creates a map of indices from entries in | |
1027 // scratch_cp to the corresponding entry in *merge_cp_p. Index map | |
1028 // entries are only created for entries in scratch_cp that occupy a | |
1029 // different location in *merged_cp_p. | |
1030 bool VM_RedefineClasses::merge_constant_pools(constantPoolHandle old_cp, | |
1031 constantPoolHandle scratch_cp, constantPoolHandle *merge_cp_p, | |
1032 int *merge_cp_length_p, TRAPS) { | |
1033 | |
1034 if (merge_cp_p == NULL) { | |
1035 assert(false, "caller must provide scatch constantPool"); | |
1036 return false; // robustness | |
1037 } | |
1038 if (merge_cp_length_p == NULL) { | |
1039 assert(false, "caller must provide scatch CP length"); | |
1040 return false; // robustness | |
1041 } | |
1042 // Worst case we need old_cp->length() + scratch_cp()->length(), | |
1043 // but the caller might be smart so make sure we have at least | |
1044 // the minimum. | |
1045 if ((*merge_cp_p)->length() < old_cp->length()) { | |
1046 assert(false, "merge area too small"); | |
1047 return false; // robustness | |
1048 } | |
1049 | |
1050 RC_TRACE_WITH_THREAD(0x00010000, THREAD, | |
1051 ("old_cp_len=%d, scratch_cp_len=%d", old_cp->length(), | |
1052 scratch_cp->length())); | |
1053 | |
1054 { | |
1055 // Pass 0: | |
1056 // The old_cp is copied to *merge_cp_p; this means that any code | |
1057 // using old_cp does not have to change. This work looks like a | |
1058 // perfect fit for constantPoolOop::copy_cp_to(), but we need to | |
1059 // handle one special case: | |
1060 // - revert JVM_CONSTANT_Class to JVM_CONSTANT_UnresolvedClass | |
1061 // This will make verification happy. | |
1062 | |
1063 int old_i; // index into old_cp | |
1064 | |
1065 // index zero (0) is not used in constantPools | |
1066 for (old_i = 1; old_i < old_cp->length(); old_i++) { | |
1067 // leave debugging crumb | |
1068 jbyte old_tag = old_cp->tag_at(old_i).value(); | |
1069 switch (old_tag) { | |
1070 case JVM_CONSTANT_Class: | |
1071 // revert the copy to JVM_CONSTANT_UnresolvedClass | |
1072 (*merge_cp_p)->unresolved_klass_at_put(old_i, | |
1073 old_cp->klass_name_at(old_i)); | |
1074 break; | |
1075 | |
1076 case JVM_CONSTANT_Double: | |
1077 case JVM_CONSTANT_Long: | |
1078 // just copy the entry to *merge_cp_p, but double and long take | |
1079 // two constant pool entries | |
1080 old_cp->copy_entry_to(old_i, *merge_cp_p, old_i, CHECK_0); | |
1081 old_i++; | |
1082 break; | |
1083 | |
1084 default: | |
1085 // just copy the entry to *merge_cp_p | |
1086 old_cp->copy_entry_to(old_i, *merge_cp_p, old_i, CHECK_0); | |
1087 break; | |
1088 } | |
1089 } // end for each old_cp entry | |
1090 | |
1091 // We don't need to sanity check that *merge_cp_length_p is within | |
1092 // *merge_cp_p bounds since we have the minimum on-entry check above. | |
1093 (*merge_cp_length_p) = old_i; | |
1094 } | |
1095 | |
1096 // merge_cp_len should be the same as old_cp->length() at this point | |
1097 // so this trace message is really a "warm-and-breathing" message. | |
1098 RC_TRACE_WITH_THREAD(0x00020000, THREAD, | |
1099 ("after pass 0: merge_cp_len=%d", *merge_cp_length_p)); | |
1100 | |
1101 int scratch_i; // index into scratch_cp | |
1102 { | |
1103 // Pass 1a: | |
1104 // Compare scratch_cp entries to the old_cp entries that we have | |
1105 // already copied to *merge_cp_p. In this pass, we are eliminating | |
1106 // exact duplicates (matching entry at same index) so we only | |
1107 // compare entries in the common indice range. | |
1108 int increment = 1; | |
1109 int pass1a_length = MIN2(old_cp->length(), scratch_cp->length()); | |
1110 for (scratch_i = 1; scratch_i < pass1a_length; scratch_i += increment) { | |
1111 switch (scratch_cp->tag_at(scratch_i).value()) { | |
1112 case JVM_CONSTANT_Double: | |
1113 case JVM_CONSTANT_Long: | |
1114 // double and long take two constant pool entries | |
1115 increment = 2; | |
1116 break; | |
1117 | |
1118 default: | |
1119 increment = 1; | |
1120 break; | |
1121 } | |
1122 | |
1123 bool match = scratch_cp->compare_entry_to(scratch_i, *merge_cp_p, | |
1124 scratch_i, CHECK_0); | |
1125 if (match) { | |
1126 // found a match at the same index so nothing more to do | |
1127 continue; | |
1128 } else if (is_unresolved_class_mismatch(scratch_cp, scratch_i, | |
1129 *merge_cp_p, scratch_i)) { | |
1130 // The mismatch in compare_entry_to() above is because of a | |
1131 // resolved versus unresolved class entry at the same index | |
1132 // with the same string value. Since Pass 0 reverted any | |
1133 // class entries to unresolved class entries in *merge_cp_p, | |
1134 // we go with the unresolved class entry. | |
1135 continue; | |
1136 } else if (is_unresolved_string_mismatch(scratch_cp, scratch_i, | |
1137 *merge_cp_p, scratch_i)) { | |
1138 // The mismatch in compare_entry_to() above is because of a | |
1139 // resolved versus unresolved string entry at the same index | |
1140 // with the same string value. We can live with whichever | |
1141 // happens to be at scratch_i in *merge_cp_p. | |
1142 continue; | |
1143 } | |
1144 | |
1145 int found_i = scratch_cp->find_matching_entry(scratch_i, *merge_cp_p, | |
1146 CHECK_0); | |
1147 if (found_i != 0) { | |
1148 guarantee(found_i != scratch_i, | |
1149 "compare_entry_to() and find_matching_entry() do not agree"); | |
1150 | |
1151 // Found a matching entry somewhere else in *merge_cp_p so | |
1152 // just need a mapping entry. | |
1153 map_index(scratch_cp, scratch_i, found_i); | |
1154 continue; | |
1155 } | |
1156 | |
1157 // The find_matching_entry() call above could fail to find a match | |
1158 // due to a resolved versus unresolved class or string entry situation | |
1159 // like we solved above with the is_unresolved_*_mismatch() calls. | |
1160 // However, we would have to call is_unresolved_*_mismatch() over | |
1161 // all of *merge_cp_p (potentially) and that doesn't seem to be | |
1162 // worth the time. | |
1163 | |
1164 // No match found so we have to append this entry and any unique | |
1165 // referenced entries to *merge_cp_p. | |
1166 append_entry(scratch_cp, scratch_i, merge_cp_p, merge_cp_length_p, | |
1167 CHECK_0); | |
1168 } | |
1169 } | |
1170 | |
1171 RC_TRACE_WITH_THREAD(0x00020000, THREAD, | |
1172 ("after pass 1a: merge_cp_len=%d, scratch_i=%d, index_map_len=%d", | |
1173 *merge_cp_length_p, scratch_i, _index_map_count)); | |
1174 | |
1175 if (scratch_i < scratch_cp->length()) { | |
1176 // Pass 1b: | |
1177 // old_cp is smaller than scratch_cp so there are entries in | |
1178 // scratch_cp that we have not yet processed. We take care of | |
1179 // those now. | |
1180 int increment = 1; | |
1181 for (; scratch_i < scratch_cp->length(); scratch_i += increment) { | |
1182 switch (scratch_cp->tag_at(scratch_i).value()) { | |
1183 case JVM_CONSTANT_Double: | |
1184 case JVM_CONSTANT_Long: | |
1185 // double and long take two constant pool entries | |
1186 increment = 2; | |
1187 break; | |
1188 | |
1189 default: | |
1190 increment = 1; | |
1191 break; | |
1192 } | |
1193 | |
1194 int found_i = | |
1195 scratch_cp->find_matching_entry(scratch_i, *merge_cp_p, CHECK_0); | |
1196 if (found_i != 0) { | |
1197 // Found a matching entry somewhere else in *merge_cp_p so | |
1198 // just need a mapping entry. | |
1199 map_index(scratch_cp, scratch_i, found_i); | |
1200 continue; | |
1201 } | |
1202 | |
1203 // No match found so we have to append this entry and any unique | |
1204 // referenced entries to *merge_cp_p. | |
1205 append_entry(scratch_cp, scratch_i, merge_cp_p, merge_cp_length_p, | |
1206 CHECK_0); | |
1207 } | |
1208 | |
1209 RC_TRACE_WITH_THREAD(0x00020000, THREAD, | |
1210 ("after pass 1b: merge_cp_len=%d, scratch_i=%d, index_map_len=%d", | |
1211 *merge_cp_length_p, scratch_i, _index_map_count)); | |
1212 } | |
1213 | |
1214 return true; | |
1215 } // end merge_constant_pools() | |
1216 | |
1217 | |
1218 // Merge constant pools between the_class and scratch_class and | |
1219 // potentially rewrite bytecodes in scratch_class to use the merged | |
1220 // constant pool. | |
1221 jvmtiError VM_RedefineClasses::merge_cp_and_rewrite( | |
1222 instanceKlassHandle the_class, instanceKlassHandle scratch_class, | |
1223 TRAPS) { | |
1224 // worst case merged constant pool length is old and new combined | |
1225 int merge_cp_length = the_class->constants()->length() | |
1226 + scratch_class->constants()->length(); | |
1227 | |
1228 constantPoolHandle old_cp(THREAD, the_class->constants()); | |
1229 constantPoolHandle scratch_cp(THREAD, scratch_class->constants()); | |
1230 | |
1231 // Constant pools are not easily reused so we allocate a new one | |
1232 // each time. | |
1233 constantPoolHandle merge_cp(THREAD, | |
1234 oopFactory::new_constantPool(merge_cp_length, THREAD)); | |
1235 int orig_length = old_cp->orig_length(); | |
1236 if (orig_length == 0) { | |
1237 // This old_cp is an actual original constant pool. We save | |
1238 // the original length in the merged constant pool so that | |
1239 // merge_constant_pools() can be more efficient. If a constant | |
1240 // pool has a non-zero orig_length() value, then that constant | |
1241 // pool was created by a merge operation in RedefineClasses. | |
1242 merge_cp->set_orig_length(old_cp->length()); | |
1243 } else { | |
1244 // This old_cp is a merged constant pool from a previous | |
1245 // RedefineClasses() calls so just copy the orig_length() | |
1246 // value. | |
1247 merge_cp->set_orig_length(old_cp->orig_length()); | |
1248 } | |
1249 | |
1250 ResourceMark rm(THREAD); | |
1251 _index_map_count = 0; | |
1252 _index_map_p = new intArray(scratch_cp->length(), -1); | |
1253 | |
1254 bool result = merge_constant_pools(old_cp, scratch_cp, &merge_cp, | |
1255 &merge_cp_length, THREAD); | |
1256 if (!result) { | |
1257 // The merge can fail due to memory allocation failure or due | |
1258 // to robustness checks. | |
1259 return JVMTI_ERROR_INTERNAL; | |
1260 } | |
1261 | |
1262 RC_TRACE_WITH_THREAD(0x00010000, THREAD, | |
1263 ("merge_cp_len=%d, index_map_len=%d", merge_cp_length, _index_map_count)); | |
1264 | |
1265 if (_index_map_count == 0) { | |
1266 // there is nothing to map between the new and merged constant pools | |
1267 | |
1268 if (old_cp->length() == scratch_cp->length()) { | |
1269 // The old and new constant pools are the same length and the | |
1270 // index map is empty. This means that the three constant pools | |
1271 // are equivalent (but not the same). Unfortunately, the new | |
1272 // constant pool has not gone through link resolution nor have | |
1273 // the new class bytecodes gone through constant pool cache | |
1274 // rewriting so we can't use the old constant pool with the new | |
1275 // class. | |
1276 | |
1277 merge_cp = constantPoolHandle(); // toss the merged constant pool | |
1278 } else if (old_cp->length() < scratch_cp->length()) { | |
1279 // The old constant pool has fewer entries than the new constant | |
1280 // pool and the index map is empty. This means the new constant | |
1281 // pool is a superset of the old constant pool. However, the old | |
1282 // class bytecodes have already gone through constant pool cache | |
1283 // rewriting so we can't use the new constant pool with the old | |
1284 // class. | |
1285 | |
1286 merge_cp = constantPoolHandle(); // toss the merged constant pool | |
1287 } else { | |
1288 // The old constant pool has more entries than the new constant | |
1289 // pool and the index map is empty. This means that both the old | |
1290 // and merged constant pools are supersets of the new constant | |
1291 // pool. | |
1292 | |
1293 // Replace the new constant pool with a shrunken copy of the | |
1294 // merged constant pool; the previous new constant pool will | |
1295 // get GCed. | |
1296 set_new_constant_pool(scratch_class, merge_cp, merge_cp_length, true, | |
1297 THREAD); | |
1298 // drop local ref to the merged constant pool | |
1299 merge_cp = constantPoolHandle(); | |
1300 } | |
1301 } else { | |
1302 if (RC_TRACE_ENABLED(0x00040000)) { | |
1303 // don't want to loop unless we are tracing | |
1304 int count = 0; | |
1305 for (int i = 1; i < _index_map_p->length(); i++) { | |
1306 int value = _index_map_p->at(i); | |
1307 | |
1308 if (value != -1) { | |
1309 RC_TRACE_WITH_THREAD(0x00040000, THREAD, | |
1310 ("index_map[%d]: old=%d new=%d", count, i, value)); | |
1311 count++; | |
1312 } | |
1313 } | |
1314 } | |
1315 | |
1316 // We have entries mapped between the new and merged constant pools | |
1317 // so we have to rewrite some constant pool references. | |
1318 if (!rewrite_cp_refs(scratch_class, THREAD)) { | |
1319 return JVMTI_ERROR_INTERNAL; | |
1320 } | |
1321 | |
1322 // Replace the new constant pool with a shrunken copy of the | |
1323 // merged constant pool so now the rewritten bytecodes have | |
1324 // valid references; the previous new constant pool will get | |
1325 // GCed. | |
1326 set_new_constant_pool(scratch_class, merge_cp, merge_cp_length, true, | |
1327 THREAD); | |
1328 } | |
1329 | |
1330 return JVMTI_ERROR_NONE; | |
1331 } // end merge_cp_and_rewrite() | |
1332 | |
1333 | |
1334 // Rewrite constant pool references in klass scratch_class. | |
1335 bool VM_RedefineClasses::rewrite_cp_refs(instanceKlassHandle scratch_class, | |
1336 TRAPS) { | |
1337 | |
1338 // rewrite constant pool references in the methods: | |
1339 if (!rewrite_cp_refs_in_methods(scratch_class, THREAD)) { | |
1340 // propogate failure back to caller | |
1341 return false; | |
1342 } | |
1343 | |
1344 // rewrite constant pool references in the class_annotations: | |
1345 if (!rewrite_cp_refs_in_class_annotations(scratch_class, THREAD)) { | |
1346 // propogate failure back to caller | |
1347 return false; | |
1348 } | |
1349 | |
1350 // rewrite constant pool references in the fields_annotations: | |
1351 if (!rewrite_cp_refs_in_fields_annotations(scratch_class, THREAD)) { | |
1352 // propogate failure back to caller | |
1353 return false; | |
1354 } | |
1355 | |
1356 // rewrite constant pool references in the methods_annotations: | |
1357 if (!rewrite_cp_refs_in_methods_annotations(scratch_class, THREAD)) { | |
1358 // propogate failure back to caller | |
1359 return false; | |
1360 } | |
1361 | |
1362 // rewrite constant pool references in the methods_parameter_annotations: | |
1363 if (!rewrite_cp_refs_in_methods_parameter_annotations(scratch_class, | |
1364 THREAD)) { | |
1365 // propogate failure back to caller | |
1366 return false; | |
1367 } | |
1368 | |
1369 // rewrite constant pool references in the methods_default_annotations: | |
1370 if (!rewrite_cp_refs_in_methods_default_annotations(scratch_class, | |
1371 THREAD)) { | |
1372 // propogate failure back to caller | |
1373 return false; | |
1374 } | |
1375 | |
1376 return true; | |
1377 } // end rewrite_cp_refs() | |
1378 | |
1379 | |
1380 // Rewrite constant pool references in the methods. | |
1381 bool VM_RedefineClasses::rewrite_cp_refs_in_methods( | |
1382 instanceKlassHandle scratch_class, TRAPS) { | |
1383 | |
1384 objArrayHandle methods(THREAD, scratch_class->methods()); | |
1385 | |
1386 if (methods.is_null() || methods->length() == 0) { | |
1387 // no methods so nothing to do | |
1388 return true; | |
1389 } | |
1390 | |
1391 // rewrite constant pool references in the methods: | |
1392 for (int i = methods->length() - 1; i >= 0; i--) { | |
1393 methodHandle method(THREAD, (methodOop)methods->obj_at(i)); | |
1394 methodHandle new_method; | |
1395 rewrite_cp_refs_in_method(method, &new_method, CHECK_false); | |
1396 if (!new_method.is_null()) { | |
1397 // the method has been replaced so save the new method version | |
1398 methods->obj_at_put(i, new_method()); | |
1399 } | |
1400 } | |
1401 | |
1402 return true; | |
1403 } | |
1404 | |
1405 | |
1406 // Rewrite constant pool references in the specific method. This code | |
1407 // was adapted from Rewriter::rewrite_method(). | |
1408 void VM_RedefineClasses::rewrite_cp_refs_in_method(methodHandle method, | |
1409 methodHandle *new_method_p, TRAPS) { | |
1410 | |
1411 *new_method_p = methodHandle(); // default is no new method | |
1412 | |
1413 // We cache a pointer to the bytecodes here in code_base. If GC | |
1414 // moves the methodOop, then the bytecodes will also move which | |
1415 // will likely cause a crash. We create a No_Safepoint_Verifier | |
1416 // object to detect whether we pass a possible safepoint in this | |
1417 // code block. | |
1418 No_Safepoint_Verifier nsv; | |
1419 | |
1420 // Bytecodes and their length | |
1421 address code_base = method->code_base(); | |
1422 int code_length = method->code_size(); | |
1423 | |
1424 int bc_length; | |
1425 for (int bci = 0; bci < code_length; bci += bc_length) { | |
1426 address bcp = code_base + bci; | |
1427 Bytecodes::Code c = (Bytecodes::Code)(*bcp); | |
1428 | |
1429 bc_length = Bytecodes::length_for(c); | |
1430 if (bc_length == 0) { | |
1431 // More complicated bytecodes report a length of zero so | |
1432 // we have to try again a slightly different way. | |
1433 bc_length = Bytecodes::length_at(bcp); | |
1434 } | |
1435 | |
1436 assert(bc_length != 0, "impossible bytecode length"); | |
1437 | |
1438 switch (c) { | |
1439 case Bytecodes::_ldc: | |
1440 { | |
1441 int cp_index = *(bcp + 1); | |
1442 int new_index = find_new_index(cp_index); | |
1443 | |
1444 if (StressLdcRewrite && new_index == 0) { | |
1445 // If we are stressing ldc -> ldc_w rewriting, then we | |
1446 // always need a new_index value. | |
1447 new_index = cp_index; | |
1448 } | |
1449 if (new_index != 0) { | |
1450 // the original index is mapped so we have more work to do | |
1451 if (!StressLdcRewrite && new_index <= max_jubyte) { | |
1452 // The new value can still use ldc instead of ldc_w | |
1453 // unless we are trying to stress ldc -> ldc_w rewriting | |
1454 RC_TRACE_WITH_THREAD(0x00080000, THREAD, | |
1455 ("%s@" INTPTR_FORMAT " old=%d, new=%d", Bytecodes::name(c), | |
1456 bcp, cp_index, new_index)); | |
1457 *(bcp + 1) = new_index; | |
1458 } else { | |
1459 RC_TRACE_WITH_THREAD(0x00080000, THREAD, | |
1460 ("%s->ldc_w@" INTPTR_FORMAT " old=%d, new=%d", | |
1461 Bytecodes::name(c), bcp, cp_index, new_index)); | |
1462 // the new value needs ldc_w instead of ldc | |
1463 u_char inst_buffer[4]; // max instruction size is 4 bytes | |
1464 bcp = (address)inst_buffer; | |
1465 // construct new instruction sequence | |
1466 *bcp = Bytecodes::_ldc_w; | |
1467 bcp++; | |
1468 // Rewriter::rewrite_method() does not rewrite ldc -> ldc_w. | |
1469 // See comment below for difference between put_Java_u2() | |
1470 // and put_native_u2(). | |
1471 Bytes::put_Java_u2(bcp, new_index); | |
1472 | |
1473 Relocator rc(method, NULL /* no RelocatorListener needed */); | |
1474 methodHandle m; | |
1475 { | |
1476 Pause_No_Safepoint_Verifier pnsv(&nsv); | |
1477 | |
1478 // ldc is 2 bytes and ldc_w is 3 bytes | |
1479 m = rc.insert_space_at(bci, 3, inst_buffer, THREAD); | |
1480 if (m.is_null() || HAS_PENDING_EXCEPTION) { | |
1481 guarantee(false, "insert_space_at() failed"); | |
1482 } | |
1483 } | |
1484 | |
1485 // return the new method so that the caller can update | |
1486 // the containing class | |
1487 *new_method_p = method = m; | |
1488 // switch our bytecode processing loop from the old method | |
1489 // to the new method | |
1490 code_base = method->code_base(); | |
1491 code_length = method->code_size(); | |
1492 bcp = code_base + bci; | |
1493 c = (Bytecodes::Code)(*bcp); | |
1494 bc_length = Bytecodes::length_for(c); | |
1495 assert(bc_length != 0, "sanity check"); | |
1496 } // end we need ldc_w instead of ldc | |
1497 } // end if there is a mapped index | |
1498 } break; | |
1499 | |
1500 // these bytecodes have a two-byte constant pool index | |
1501 case Bytecodes::_anewarray : // fall through | |
1502 case Bytecodes::_checkcast : // fall through | |
1503 case Bytecodes::_getfield : // fall through | |
1504 case Bytecodes::_getstatic : // fall through | |
1505 case Bytecodes::_instanceof : // fall through | |
1506 case Bytecodes::_invokeinterface: // fall through | |
1507 case Bytecodes::_invokespecial : // fall through | |
1508 case Bytecodes::_invokestatic : // fall through | |
1509 case Bytecodes::_invokevirtual : // fall through | |
1510 case Bytecodes::_ldc_w : // fall through | |
1511 case Bytecodes::_ldc2_w : // fall through | |
1512 case Bytecodes::_multianewarray : // fall through | |
1513 case Bytecodes::_new : // fall through | |
1514 case Bytecodes::_putfield : // fall through | |
1515 case Bytecodes::_putstatic : | |
1516 { | |
1517 address p = bcp + 1; | |
1518 int cp_index = Bytes::get_Java_u2(p); | |
1519 int new_index = find_new_index(cp_index); | |
1520 if (new_index != 0) { | |
1521 // the original index is mapped so update w/ new value | |
1522 RC_TRACE_WITH_THREAD(0x00080000, THREAD, | |
1523 ("%s@" INTPTR_FORMAT " old=%d, new=%d", Bytecodes::name(c), | |
1524 bcp, cp_index, new_index)); | |
1525 // Rewriter::rewrite_method() uses put_native_u2() in this | |
1526 // situation because it is reusing the constant pool index | |
1527 // location for a native index into the constantPoolCache. | |
1528 // Since we are updating the constant pool index prior to | |
1529 // verification and constantPoolCache initialization, we | |
1530 // need to keep the new index in Java byte order. | |
1531 Bytes::put_Java_u2(p, new_index); | |
1532 } | |
1533 } break; | |
1534 } | |
1535 } // end for each bytecode | |
1536 } // end rewrite_cp_refs_in_method() | |
1537 | |
1538 | |
1539 // Rewrite constant pool references in the class_annotations field. | |
1540 bool VM_RedefineClasses::rewrite_cp_refs_in_class_annotations( | |
1541 instanceKlassHandle scratch_class, TRAPS) { | |
1542 | |
1543 typeArrayHandle class_annotations(THREAD, | |
1544 scratch_class->class_annotations()); | |
1545 if (class_annotations.is_null() || class_annotations->length() == 0) { | |
1546 // no class_annotations so nothing to do | |
1547 return true; | |
1548 } | |
1549 | |
1550 RC_TRACE_WITH_THREAD(0x02000000, THREAD, | |
1551 ("class_annotations length=%d", class_annotations->length())); | |
1552 | |
1553 int byte_i = 0; // byte index into class_annotations | |
1554 return rewrite_cp_refs_in_annotations_typeArray(class_annotations, byte_i, | |
1555 THREAD); | |
1556 } | |
1557 | |
1558 | |
1559 // Rewrite constant pool references in an annotations typeArray. This | |
1560 // "structure" is adapted from the RuntimeVisibleAnnotations_attribute | |
1561 // that is described in section 4.8.15 of the 2nd-edition of the VM spec: | |
1562 // | |
1563 // annotations_typeArray { | |
1564 // u2 num_annotations; | |
1565 // annotation annotations[num_annotations]; | |
1566 // } | |
1567 // | |
1568 bool VM_RedefineClasses::rewrite_cp_refs_in_annotations_typeArray( | |
1569 typeArrayHandle annotations_typeArray, int &byte_i_ref, TRAPS) { | |
1570 | |
1571 if ((byte_i_ref + 2) > annotations_typeArray->length()) { | |
1572 // not enough room for num_annotations field | |
1573 RC_TRACE_WITH_THREAD(0x02000000, THREAD, | |
1574 ("length() is too small for num_annotations field")); | |
1575 return false; | |
1576 } | |
1577 | |
1578 u2 num_annotations = Bytes::get_Java_u2((address) | |
1579 annotations_typeArray->byte_at_addr(byte_i_ref)); | |
1580 byte_i_ref += 2; | |
1581 | |
1582 RC_TRACE_WITH_THREAD(0x02000000, THREAD, | |
1583 ("num_annotations=%d", num_annotations)); | |
1584 | |
1585 int calc_num_annotations = 0; | |
1586 for (; calc_num_annotations < num_annotations; calc_num_annotations++) { | |
1587 if (!rewrite_cp_refs_in_annotation_struct(annotations_typeArray, | |
1588 byte_i_ref, THREAD)) { | |
1589 RC_TRACE_WITH_THREAD(0x02000000, THREAD, | |
1590 ("bad annotation_struct at %d", calc_num_annotations)); | |
1591 // propogate failure back to caller | |
1592 return false; | |
1593 } | |
1594 } | |
1595 assert(num_annotations == calc_num_annotations, "sanity check"); | |
1596 | |
1597 return true; | |
1598 } // end rewrite_cp_refs_in_annotations_typeArray() | |
1599 | |
1600 | |
1601 // Rewrite constant pool references in the annotation struct portion of | |
1602 // an annotations_typeArray. This "structure" is from section 4.8.15 of | |
1603 // the 2nd-edition of the VM spec: | |
1604 // | |
1605 // struct annotation { | |
1606 // u2 type_index; | |
1607 // u2 num_element_value_pairs; | |
1608 // { | |
1609 // u2 element_name_index; | |
1610 // element_value value; | |
1611 // } element_value_pairs[num_element_value_pairs]; | |
1612 // } | |
1613 // | |
1614 bool VM_RedefineClasses::rewrite_cp_refs_in_annotation_struct( | |
1615 typeArrayHandle annotations_typeArray, int &byte_i_ref, TRAPS) { | |
1616 if ((byte_i_ref + 2 + 2) > annotations_typeArray->length()) { | |
1617 // not enough room for smallest annotation_struct | |
1618 RC_TRACE_WITH_THREAD(0x02000000, THREAD, | |
1619 ("length() is too small for annotation_struct")); | |
1620 return false; | |
1621 } | |
1622 | |
1623 u2 type_index = rewrite_cp_ref_in_annotation_data(annotations_typeArray, | |
1624 byte_i_ref, "mapped old type_index=%d", THREAD); | |
1625 | |
1626 u2 num_element_value_pairs = Bytes::get_Java_u2((address) | |
1627 annotations_typeArray->byte_at_addr( | |
1628 byte_i_ref)); | |
1629 byte_i_ref += 2; | |
1630 | |
1631 RC_TRACE_WITH_THREAD(0x02000000, THREAD, | |
1632 ("type_index=%d num_element_value_pairs=%d", type_index, | |
1633 num_element_value_pairs)); | |
1634 | |
1635 int calc_num_element_value_pairs = 0; | |
1636 for (; calc_num_element_value_pairs < num_element_value_pairs; | |
1637 calc_num_element_value_pairs++) { | |
1638 if ((byte_i_ref + 2) > annotations_typeArray->length()) { | |
1639 // not enough room for another element_name_index, let alone | |
1640 // the rest of another component | |
1641 RC_TRACE_WITH_THREAD(0x02000000, THREAD, | |
1642 ("length() is too small for element_name_index")); | |
1643 return false; | |
1644 } | |
1645 | |
1646 u2 element_name_index = rewrite_cp_ref_in_annotation_data( | |
1647 annotations_typeArray, byte_i_ref, | |
1648 "mapped old element_name_index=%d", THREAD); | |
1649 | |
1650 RC_TRACE_WITH_THREAD(0x02000000, THREAD, | |
1651 ("element_name_index=%d", element_name_index)); | |
1652 | |
1653 if (!rewrite_cp_refs_in_element_value(annotations_typeArray, | |
1654 byte_i_ref, THREAD)) { | |
1655 RC_TRACE_WITH_THREAD(0x02000000, THREAD, | |
1656 ("bad element_value at %d", calc_num_element_value_pairs)); | |
1657 // propogate failure back to caller | |
1658 return false; | |
1659 } | |
1660 } // end for each component | |
1661 assert(num_element_value_pairs == calc_num_element_value_pairs, | |
1662 "sanity check"); | |
1663 | |
1664 return true; | |
1665 } // end rewrite_cp_refs_in_annotation_struct() | |
1666 | |
1667 | |
1668 // Rewrite a constant pool reference at the current position in | |
1669 // annotations_typeArray if needed. Returns the original constant | |
1670 // pool reference if a rewrite was not needed or the new constant | |
1671 // pool reference if a rewrite was needed. | |
1672 u2 VM_RedefineClasses::rewrite_cp_ref_in_annotation_data( | |
1673 typeArrayHandle annotations_typeArray, int &byte_i_ref, | |
1674 const char * trace_mesg, TRAPS) { | |
1675 | |
1676 address cp_index_addr = (address) | |
1677 annotations_typeArray->byte_at_addr(byte_i_ref); | |
1678 u2 old_cp_index = Bytes::get_Java_u2(cp_index_addr); | |
1679 u2 new_cp_index = find_new_index(old_cp_index); | |
1680 if (new_cp_index != 0) { | |
1681 RC_TRACE_WITH_THREAD(0x02000000, THREAD, (trace_mesg, old_cp_index)); | |
1682 Bytes::put_Java_u2(cp_index_addr, new_cp_index); | |
1683 old_cp_index = new_cp_index; | |
1684 } | |
1685 byte_i_ref += 2; | |
1686 return old_cp_index; | |
1687 } | |
1688 | |
1689 | |
1690 // Rewrite constant pool references in the element_value portion of an | |
1691 // annotations_typeArray. This "structure" is from section 4.8.15.1 of | |
1692 // the 2nd-edition of the VM spec: | |
1693 // | |
1694 // struct element_value { | |
1695 // u1 tag; | |
1696 // union { | |
1697 // u2 const_value_index; | |
1698 // { | |
1699 // u2 type_name_index; | |
1700 // u2 const_name_index; | |
1701 // } enum_const_value; | |
1702 // u2 class_info_index; | |
1703 // annotation annotation_value; | |
1704 // struct { | |
1705 // u2 num_values; | |
1706 // element_value values[num_values]; | |
1707 // } array_value; | |
1708 // } value; | |
1709 // } | |
1710 // | |
1711 bool VM_RedefineClasses::rewrite_cp_refs_in_element_value( | |
1712 typeArrayHandle annotations_typeArray, int &byte_i_ref, TRAPS) { | |
1713 | |
1714 if ((byte_i_ref + 1) > annotations_typeArray->length()) { | |
1715 // not enough room for a tag let alone the rest of an element_value | |
1716 RC_TRACE_WITH_THREAD(0x02000000, THREAD, | |
1717 ("length() is too small for a tag")); | |
1718 return false; | |
1719 } | |
1720 | |
1721 u1 tag = annotations_typeArray->byte_at(byte_i_ref); | |
1722 byte_i_ref++; | |
1723 RC_TRACE_WITH_THREAD(0x02000000, THREAD, ("tag='%c'", tag)); | |
1724 | |
1725 switch (tag) { | |
1726 // These BaseType tag values are from Table 4.2 in VM spec: | |
1727 case 'B': // byte | |
1728 case 'C': // char | |
1729 case 'D': // double | |
1730 case 'F': // float | |
1731 case 'I': // int | |
1732 case 'J': // long | |
1733 case 'S': // short | |
1734 case 'Z': // boolean | |
1735 | |
1736 // The remaining tag values are from Table 4.8 in the 2nd-edition of | |
1737 // the VM spec: | |
1738 case 's': | |
1739 { | |
1740 // For the above tag values (including the BaseType values), | |
1741 // value.const_value_index is right union field. | |
1742 | |
1743 if ((byte_i_ref + 2) > annotations_typeArray->length()) { | |
1744 // not enough room for a const_value_index | |
1745 RC_TRACE_WITH_THREAD(0x02000000, THREAD, | |
1746 ("length() is too small for a const_value_index")); | |
1747 return false; | |
1748 } | |
1749 | |
1750 u2 const_value_index = rewrite_cp_ref_in_annotation_data( | |
1751 annotations_typeArray, byte_i_ref, | |
1752 "mapped old const_value_index=%d", THREAD); | |
1753 | |
1754 RC_TRACE_WITH_THREAD(0x02000000, THREAD, | |
1755 ("const_value_index=%d", const_value_index)); | |
1756 } break; | |
1757 | |
1758 case 'e': | |
1759 { | |
1760 // for the above tag value, value.enum_const_value is right union field | |
1761 | |
1762 if ((byte_i_ref + 4) > annotations_typeArray->length()) { | |
1763 // not enough room for a enum_const_value | |
1764 RC_TRACE_WITH_THREAD(0x02000000, THREAD, | |
1765 ("length() is too small for a enum_const_value")); | |
1766 return false; | |
1767 } | |
1768 | |
1769 u2 type_name_index = rewrite_cp_ref_in_annotation_data( | |
1770 annotations_typeArray, byte_i_ref, | |
1771 "mapped old type_name_index=%d", THREAD); | |
1772 | |
1773 u2 const_name_index = rewrite_cp_ref_in_annotation_data( | |
1774 annotations_typeArray, byte_i_ref, | |
1775 "mapped old const_name_index=%d", THREAD); | |
1776 | |
1777 RC_TRACE_WITH_THREAD(0x02000000, THREAD, | |
1778 ("type_name_index=%d const_name_index=%d", type_name_index, | |
1779 const_name_index)); | |
1780 } break; | |
1781 | |
1782 case 'c': | |
1783 { | |
1784 // for the above tag value, value.class_info_index is right union field | |
1785 | |
1786 if ((byte_i_ref + 2) > annotations_typeArray->length()) { | |
1787 // not enough room for a class_info_index | |
1788 RC_TRACE_WITH_THREAD(0x02000000, THREAD, | |
1789 ("length() is too small for a class_info_index")); | |
1790 return false; | |
1791 } | |
1792 | |
1793 u2 class_info_index = rewrite_cp_ref_in_annotation_data( | |
1794 annotations_typeArray, byte_i_ref, | |
1795 "mapped old class_info_index=%d", THREAD); | |
1796 | |
1797 RC_TRACE_WITH_THREAD(0x02000000, THREAD, | |
1798 ("class_info_index=%d", class_info_index)); | |
1799 } break; | |
1800 | |
1801 case '@': | |
1802 // For the above tag value, value.attr_value is the right union | |
1803 // field. This is a nested annotation. | |
1804 if (!rewrite_cp_refs_in_annotation_struct(annotations_typeArray, | |
1805 byte_i_ref, THREAD)) { | |
1806 // propogate failure back to caller | |
1807 return false; | |
1808 } | |
1809 break; | |
1810 | |
1811 case '[': | |
1812 { | |
1813 if ((byte_i_ref + 2) > annotations_typeArray->length()) { | |
1814 // not enough room for a num_values field | |
1815 RC_TRACE_WITH_THREAD(0x02000000, THREAD, | |
1816 ("length() is too small for a num_values field")); | |
1817 return false; | |
1818 } | |
1819 | |
1820 // For the above tag value, value.array_value is the right union | |
1821 // field. This is an array of nested element_value. | |
1822 u2 num_values = Bytes::get_Java_u2((address) | |
1823 annotations_typeArray->byte_at_addr(byte_i_ref)); | |
1824 byte_i_ref += 2; | |
1825 RC_TRACE_WITH_THREAD(0x02000000, THREAD, ("num_values=%d", num_values)); | |
1826 | |
1827 int calc_num_values = 0; | |
1828 for (; calc_num_values < num_values; calc_num_values++) { | |
1829 if (!rewrite_cp_refs_in_element_value( | |
1830 annotations_typeArray, byte_i_ref, THREAD)) { | |
1831 RC_TRACE_WITH_THREAD(0x02000000, THREAD, | |
1832 ("bad nested element_value at %d", calc_num_values)); | |
1833 // propogate failure back to caller | |
1834 return false; | |
1835 } | |
1836 } | |
1837 assert(num_values == calc_num_values, "sanity check"); | |
1838 } break; | |
1839 | |
1840 default: | |
1841 RC_TRACE_WITH_THREAD(0x02000000, THREAD, ("bad tag=0x%x", tag)); | |
1842 return false; | |
1843 } // end decode tag field | |
1844 | |
1845 return true; | |
1846 } // end rewrite_cp_refs_in_element_value() | |
1847 | |
1848 | |
1849 // Rewrite constant pool references in a fields_annotations field. | |
1850 bool VM_RedefineClasses::rewrite_cp_refs_in_fields_annotations( | |
1851 instanceKlassHandle scratch_class, TRAPS) { | |
1852 | |
1853 objArrayHandle fields_annotations(THREAD, | |
1854 scratch_class->fields_annotations()); | |
1855 | |
1856 if (fields_annotations.is_null() || fields_annotations->length() == 0) { | |
1857 // no fields_annotations so nothing to do | |
1858 return true; | |
1859 } | |
1860 | |
1861 RC_TRACE_WITH_THREAD(0x02000000, THREAD, | |
1862 ("fields_annotations length=%d", fields_annotations->length())); | |
1863 | |
1864 for (int i = 0; i < fields_annotations->length(); i++) { | |
1865 typeArrayHandle field_annotations(THREAD, | |
1866 (typeArrayOop)fields_annotations->obj_at(i)); | |
1867 if (field_annotations.is_null() || field_annotations->length() == 0) { | |
1868 // this field does not have any annotations so skip it | |
1869 continue; | |
1870 } | |
1871 | |
1872 int byte_i = 0; // byte index into field_annotations | |
1873 if (!rewrite_cp_refs_in_annotations_typeArray(field_annotations, byte_i, | |
1874 THREAD)) { | |
1875 RC_TRACE_WITH_THREAD(0x02000000, THREAD, | |
1876 ("bad field_annotations at %d", i)); | |
1877 // propogate failure back to caller | |
1878 return false; | |
1879 } | |
1880 } | |
1881 | |
1882 return true; | |
1883 } // end rewrite_cp_refs_in_fields_annotations() | |
1884 | |
1885 | |
1886 // Rewrite constant pool references in a methods_annotations field. | |
1887 bool VM_RedefineClasses::rewrite_cp_refs_in_methods_annotations( | |
1888 instanceKlassHandle scratch_class, TRAPS) { | |
1889 | |
1890 objArrayHandle methods_annotations(THREAD, | |
1891 scratch_class->methods_annotations()); | |
1892 | |
1893 if (methods_annotations.is_null() || methods_annotations->length() == 0) { | |
1894 // no methods_annotations so nothing to do | |
1895 return true; | |
1896 } | |
1897 | |
1898 RC_TRACE_WITH_THREAD(0x02000000, THREAD, | |
1899 ("methods_annotations length=%d", methods_annotations->length())); | |
1900 | |
1901 for (int i = 0; i < methods_annotations->length(); i++) { | |
1902 typeArrayHandle method_annotations(THREAD, | |
1903 (typeArrayOop)methods_annotations->obj_at(i)); | |
1904 if (method_annotations.is_null() || method_annotations->length() == 0) { | |
1905 // this method does not have any annotations so skip it | |
1906 continue; | |
1907 } | |
1908 | |
1909 int byte_i = 0; // byte index into method_annotations | |
1910 if (!rewrite_cp_refs_in_annotations_typeArray(method_annotations, byte_i, | |
1911 THREAD)) { | |
1912 RC_TRACE_WITH_THREAD(0x02000000, THREAD, | |
1913 ("bad method_annotations at %d", i)); | |
1914 // propogate failure back to caller | |
1915 return false; | |
1916 } | |
1917 } | |
1918 | |
1919 return true; | |
1920 } // end rewrite_cp_refs_in_methods_annotations() | |
1921 | |
1922 | |
1923 // Rewrite constant pool references in a methods_parameter_annotations | |
1924 // field. This "structure" is adapted from the | |
1925 // RuntimeVisibleParameterAnnotations_attribute described in section | |
1926 // 4.8.17 of the 2nd-edition of the VM spec: | |
1927 // | |
1928 // methods_parameter_annotations_typeArray { | |
1929 // u1 num_parameters; | |
1930 // { | |
1931 // u2 num_annotations; | |
1932 // annotation annotations[num_annotations]; | |
1933 // } parameter_annotations[num_parameters]; | |
1934 // } | |
1935 // | |
1936 bool VM_RedefineClasses::rewrite_cp_refs_in_methods_parameter_annotations( | |
1937 instanceKlassHandle scratch_class, TRAPS) { | |
1938 | |
1939 objArrayHandle methods_parameter_annotations(THREAD, | |
1940 scratch_class->methods_parameter_annotations()); | |
1941 | |
1942 if (methods_parameter_annotations.is_null() | |
1943 || methods_parameter_annotations->length() == 0) { | |
1944 // no methods_parameter_annotations so nothing to do | |
1945 return true; | |
1946 } | |
1947 | |
1948 RC_TRACE_WITH_THREAD(0x02000000, THREAD, | |
1949 ("methods_parameter_annotations length=%d", | |
1950 methods_parameter_annotations->length())); | |
1951 | |
1952 for (int i = 0; i < methods_parameter_annotations->length(); i++) { | |
1953 typeArrayHandle method_parameter_annotations(THREAD, | |
1954 (typeArrayOop)methods_parameter_annotations->obj_at(i)); | |
1955 if (method_parameter_annotations.is_null() | |
1956 || method_parameter_annotations->length() == 0) { | |
1957 // this method does not have any parameter annotations so skip it | |
1958 continue; | |
1959 } | |
1960 | |
1961 if (method_parameter_annotations->length() < 1) { | |
1962 // not enough room for a num_parameters field | |
1963 RC_TRACE_WITH_THREAD(0x02000000, THREAD, | |
1964 ("length() is too small for a num_parameters field at %d", i)); | |
1965 return false; | |
1966 } | |
1967 | |
1968 int byte_i = 0; // byte index into method_parameter_annotations | |
1969 | |
1970 u1 num_parameters = method_parameter_annotations->byte_at(byte_i); | |
1971 byte_i++; | |
1972 | |
1973 RC_TRACE_WITH_THREAD(0x02000000, THREAD, | |
1974 ("num_parameters=%d", num_parameters)); | |
1975 | |
1976 int calc_num_parameters = 0; | |
1977 for (; calc_num_parameters < num_parameters; calc_num_parameters++) { | |
1978 if (!rewrite_cp_refs_in_annotations_typeArray( | |
1979 method_parameter_annotations, byte_i, THREAD)) { | |
1980 RC_TRACE_WITH_THREAD(0x02000000, THREAD, | |
1981 ("bad method_parameter_annotations at %d", calc_num_parameters)); | |
1982 // propogate failure back to caller | |
1983 return false; | |
1984 } | |
1985 } | |
1986 assert(num_parameters == calc_num_parameters, "sanity check"); | |
1987 } | |
1988 | |
1989 return true; | |
1990 } // end rewrite_cp_refs_in_methods_parameter_annotations() | |
1991 | |
1992 | |
1993 // Rewrite constant pool references in a methods_default_annotations | |
1994 // field. This "structure" is adapted from the AnnotationDefault_attribute | |
1995 // that is described in section 4.8.19 of the 2nd-edition of the VM spec: | |
1996 // | |
1997 // methods_default_annotations_typeArray { | |
1998 // element_value default_value; | |
1999 // } | |
2000 // | |
2001 bool VM_RedefineClasses::rewrite_cp_refs_in_methods_default_annotations( | |
2002 instanceKlassHandle scratch_class, TRAPS) { | |
2003 | |
2004 objArrayHandle methods_default_annotations(THREAD, | |
2005 scratch_class->methods_default_annotations()); | |
2006 | |
2007 if (methods_default_annotations.is_null() | |
2008 || methods_default_annotations->length() == 0) { | |
2009 // no methods_default_annotations so nothing to do | |
2010 return true; | |
2011 } | |
2012 | |
2013 RC_TRACE_WITH_THREAD(0x02000000, THREAD, | |
2014 ("methods_default_annotations length=%d", | |
2015 methods_default_annotations->length())); | |
2016 | |
2017 for (int i = 0; i < methods_default_annotations->length(); i++) { | |
2018 typeArrayHandle method_default_annotations(THREAD, | |
2019 (typeArrayOop)methods_default_annotations->obj_at(i)); | |
2020 if (method_default_annotations.is_null() | |
2021 || method_default_annotations->length() == 0) { | |
2022 // this method does not have any default annotations so skip it | |
2023 continue; | |
2024 } | |
2025 | |
2026 int byte_i = 0; // byte index into method_default_annotations | |
2027 | |
2028 if (!rewrite_cp_refs_in_element_value( | |
2029 method_default_annotations, byte_i, THREAD)) { | |
2030 RC_TRACE_WITH_THREAD(0x02000000, THREAD, | |
2031 ("bad default element_value at %d", i)); | |
2032 // propogate failure back to caller | |
2033 return false; | |
2034 } | |
2035 } | |
2036 | |
2037 return true; | |
2038 } // end rewrite_cp_refs_in_methods_default_annotations() | |
2039 | |
2040 | |
2041 // Rewrite constant pool references in the method's stackmap table. | |
2042 // These "structures" are adapted from the StackMapTable_attribute that | |
2043 // is described in section 4.8.4 of the 6.0 version of the VM spec | |
2044 // (dated 2005.10.26): | |
2045 // file:///net/quincunx.sfbay/export/gbracha/ClassFile-Java6.pdf | |
2046 // | |
2047 // stack_map { | |
2048 // u2 number_of_entries; | |
2049 // stack_map_frame entries[number_of_entries]; | |
2050 // } | |
2051 // | |
2052 void VM_RedefineClasses::rewrite_cp_refs_in_stack_map_table( | |
2053 methodHandle method, TRAPS) { | |
2054 | |
2055 if (!method->has_stackmap_table()) { | |
2056 return; | |
2057 } | |
2058 | |
2059 typeArrayOop stackmap_data = method->stackmap_data(); | |
2060 address stackmap_p = (address)stackmap_data->byte_at_addr(0); | |
2061 address stackmap_end = stackmap_p + stackmap_data->length(); | |
2062 | |
2063 assert(stackmap_p + 2 <= stackmap_end, "no room for number_of_entries"); | |
2064 u2 number_of_entries = Bytes::get_Java_u2(stackmap_p); | |
2065 stackmap_p += 2; | |
2066 | |
2067 RC_TRACE_WITH_THREAD(0x04000000, THREAD, | |
2068 ("number_of_entries=%u", number_of_entries)); | |
2069 | |
2070 // walk through each stack_map_frame | |
2071 u2 calc_number_of_entries = 0; | |
2072 for (; calc_number_of_entries < number_of_entries; calc_number_of_entries++) { | |
2073 // The stack_map_frame structure is a u1 frame_type followed by | |
2074 // 0 or more bytes of data: | |
2075 // | |
2076 // union stack_map_frame { | |
2077 // same_frame; | |
2078 // same_locals_1_stack_item_frame; | |
2079 // same_locals_1_stack_item_frame_extended; | |
2080 // chop_frame; | |
2081 // same_frame_extended; | |
2082 // append_frame; | |
2083 // full_frame; | |
2084 // } | |
2085 | |
2086 assert(stackmap_p + 1 <= stackmap_end, "no room for frame_type"); | |
2087 // The Linux compiler does not like frame_type to be u1 or u2. It | |
2088 // issues the following warning for the first if-statement below: | |
2089 // | |
2090 // "warning: comparison is always true due to limited range of data type" | |
2091 // | |
2092 u4 frame_type = *stackmap_p; | |
2093 stackmap_p++; | |
2094 | |
2095 // same_frame { | |
2096 // u1 frame_type = SAME; /* 0-63 */ | |
2097 // } | |
2098 if (frame_type >= 0 && frame_type <= 63) { | |
2099 // nothing more to do for same_frame | |
2100 } | |
2101 | |
2102 // same_locals_1_stack_item_frame { | |
2103 // u1 frame_type = SAME_LOCALS_1_STACK_ITEM; /* 64-127 */ | |
2104 // verification_type_info stack[1]; | |
2105 // } | |
2106 else if (frame_type >= 64 && frame_type <= 127) { | |
2107 rewrite_cp_refs_in_verification_type_info(stackmap_p, stackmap_end, | |
2108 calc_number_of_entries, frame_type, THREAD); | |
2109 } | |
2110 | |
2111 // reserved for future use | |
2112 else if (frame_type >= 128 && frame_type <= 246) { | |
2113 // nothing more to do for reserved frame_types | |
2114 } | |
2115 | |
2116 // same_locals_1_stack_item_frame_extended { | |
2117 // u1 frame_type = SAME_LOCALS_1_STACK_ITEM_EXTENDED; /* 247 */ | |
2118 // u2 offset_delta; | |
2119 // verification_type_info stack[1]; | |
2120 // } | |
2121 else if (frame_type == 247) { | |
2122 stackmap_p += 2; | |
2123 rewrite_cp_refs_in_verification_type_info(stackmap_p, stackmap_end, | |
2124 calc_number_of_entries, frame_type, THREAD); | |
2125 } | |
2126 | |
2127 // chop_frame { | |
2128 // u1 frame_type = CHOP; /* 248-250 */ | |
2129 // u2 offset_delta; | |
2130 // } | |
2131 else if (frame_type >= 248 && frame_type <= 250) { | |
2132 stackmap_p += 2; | |
2133 } | |
2134 | |
2135 // same_frame_extended { | |
2136 // u1 frame_type = SAME_FRAME_EXTENDED; /* 251*/ | |
2137 // u2 offset_delta; | |
2138 // } | |
2139 else if (frame_type == 251) { | |
2140 stackmap_p += 2; | |
2141 } | |
2142 | |
2143 // append_frame { | |
2144 // u1 frame_type = APPEND; /* 252-254 */ | |
2145 // u2 offset_delta; | |
2146 // verification_type_info locals[frame_type - 251]; | |
2147 // } | |
2148 else if (frame_type >= 252 && frame_type <= 254) { | |
2149 assert(stackmap_p + 2 <= stackmap_end, | |
2150 "no room for offset_delta"); | |
2151 stackmap_p += 2; | |
2152 u1 len = frame_type - 251; | |
2153 for (u1 i = 0; i < len; i++) { | |
2154 rewrite_cp_refs_in_verification_type_info(stackmap_p, stackmap_end, | |
2155 calc_number_of_entries, frame_type, THREAD); | |
2156 } | |
2157 } | |
2158 | |
2159 // full_frame { | |
2160 // u1 frame_type = FULL_FRAME; /* 255 */ | |
2161 // u2 offset_delta; | |
2162 // u2 number_of_locals; | |
2163 // verification_type_info locals[number_of_locals]; | |
2164 // u2 number_of_stack_items; | |
2165 // verification_type_info stack[number_of_stack_items]; | |
2166 // } | |
2167 else if (frame_type == 255) { | |
2168 assert(stackmap_p + 2 + 2 <= stackmap_end, | |
2169 "no room for smallest full_frame"); | |
2170 stackmap_p += 2; | |
2171 | |
2172 u2 number_of_locals = Bytes::get_Java_u2(stackmap_p); | |
2173 stackmap_p += 2; | |
2174 | |
2175 for (u2 locals_i = 0; locals_i < number_of_locals; locals_i++) { | |
2176 rewrite_cp_refs_in_verification_type_info(stackmap_p, stackmap_end, | |
2177 calc_number_of_entries, frame_type, THREAD); | |
2178 } | |
2179 | |
2180 // Use the largest size for the number_of_stack_items, but only get | |
2181 // the right number of bytes. | |
2182 u2 number_of_stack_items = Bytes::get_Java_u2(stackmap_p); | |
2183 stackmap_p += 2; | |
2184 | |
2185 for (u2 stack_i = 0; stack_i < number_of_stack_items; stack_i++) { | |
2186 rewrite_cp_refs_in_verification_type_info(stackmap_p, stackmap_end, | |
2187 calc_number_of_entries, frame_type, THREAD); | |
2188 } | |
2189 } | |
2190 } // end while there is a stack_map_frame | |
2191 assert(number_of_entries == calc_number_of_entries, "sanity check"); | |
2192 } // end rewrite_cp_refs_in_stack_map_table() | |
2193 | |
2194 | |
2195 // Rewrite constant pool references in the verification type info | |
2196 // portion of the method's stackmap table. These "structures" are | |
2197 // adapted from the StackMapTable_attribute that is described in | |
2198 // section 4.8.4 of the 6.0 version of the VM spec (dated 2005.10.26): | |
2199 // file:///net/quincunx.sfbay/export/gbracha/ClassFile-Java6.pdf | |
2200 // | |
2201 // The verification_type_info structure is a u1 tag followed by 0 or | |
2202 // more bytes of data: | |
2203 // | |
2204 // union verification_type_info { | |
2205 // Top_variable_info; | |
2206 // Integer_variable_info; | |
2207 // Float_variable_info; | |
2208 // Long_variable_info; | |
2209 // Double_variable_info; | |
2210 // Null_variable_info; | |
2211 // UninitializedThis_variable_info; | |
2212 // Object_variable_info; | |
2213 // Uninitialized_variable_info; | |
2214 // } | |
2215 // | |
2216 void VM_RedefineClasses::rewrite_cp_refs_in_verification_type_info( | |
2217 address& stackmap_p_ref, address stackmap_end, u2 frame_i, | |
2218 u1 frame_type, TRAPS) { | |
2219 | |
2220 assert(stackmap_p_ref + 1 <= stackmap_end, "no room for tag"); | |
2221 u1 tag = *stackmap_p_ref; | |
2222 stackmap_p_ref++; | |
2223 | |
2224 switch (tag) { | |
2225 // Top_variable_info { | |
2226 // u1 tag = ITEM_Top; /* 0 */ | |
2227 // } | |
2228 // verificationType.hpp has zero as ITEM_Bogus instead of ITEM_Top | |
2229 case 0: // fall through | |
2230 | |
2231 // Integer_variable_info { | |
2232 // u1 tag = ITEM_Integer; /* 1 */ | |
2233 // } | |
2234 case ITEM_Integer: // fall through | |
2235 | |
2236 // Float_variable_info { | |
2237 // u1 tag = ITEM_Float; /* 2 */ | |
2238 // } | |
2239 case ITEM_Float: // fall through | |
2240 | |
2241 // Double_variable_info { | |
2242 // u1 tag = ITEM_Double; /* 3 */ | |
2243 // } | |
2244 case ITEM_Double: // fall through | |
2245 | |
2246 // Long_variable_info { | |
2247 // u1 tag = ITEM_Long; /* 4 */ | |
2248 // } | |
2249 case ITEM_Long: // fall through | |
2250 | |
2251 // Null_variable_info { | |
2252 // u1 tag = ITEM_Null; /* 5 */ | |
2253 // } | |
2254 case ITEM_Null: // fall through | |
2255 | |
2256 // UninitializedThis_variable_info { | |
2257 // u1 tag = ITEM_UninitializedThis; /* 6 */ | |
2258 // } | |
2259 case ITEM_UninitializedThis: | |
2260 // nothing more to do for the above tag types | |
2261 break; | |
2262 | |
2263 // Object_variable_info { | |
2264 // u1 tag = ITEM_Object; /* 7 */ | |
2265 // u2 cpool_index; | |
2266 // } | |
2267 case ITEM_Object: | |
2268 { | |
2269 assert(stackmap_p_ref + 2 <= stackmap_end, "no room for cpool_index"); | |
2270 u2 cpool_index = Bytes::get_Java_u2(stackmap_p_ref); | |
2271 u2 new_cp_index = find_new_index(cpool_index); | |
2272 if (new_cp_index != 0) { | |
2273 RC_TRACE_WITH_THREAD(0x04000000, THREAD, | |
2274 ("mapped old cpool_index=%d", cpool_index)); | |
2275 Bytes::put_Java_u2(stackmap_p_ref, new_cp_index); | |
2276 cpool_index = new_cp_index; | |
2277 } | |
2278 stackmap_p_ref += 2; | |
2279 | |
2280 RC_TRACE_WITH_THREAD(0x04000000, THREAD, | |
2281 ("frame_i=%u, frame_type=%u, cpool_index=%d", frame_i, | |
2282 frame_type, cpool_index)); | |
2283 } break; | |
2284 | |
2285 // Uninitialized_variable_info { | |
2286 // u1 tag = ITEM_Uninitialized; /* 8 */ | |
2287 // u2 offset; | |
2288 // } | |
2289 case ITEM_Uninitialized: | |
2290 assert(stackmap_p_ref + 2 <= stackmap_end, "no room for offset"); | |
2291 stackmap_p_ref += 2; | |
2292 break; | |
2293 | |
2294 default: | |
2295 RC_TRACE_WITH_THREAD(0x04000000, THREAD, | |
2296 ("frame_i=%u, frame_type=%u, bad tag=0x%x", frame_i, frame_type, tag)); | |
2297 ShouldNotReachHere(); | |
2298 break; | |
2299 } // end switch (tag) | |
2300 } // end rewrite_cp_refs_in_verification_type_info() | |
2301 | |
2302 | |
2303 // Change the constant pool associated with klass scratch_class to | |
2304 // scratch_cp. If shrink is true, then scratch_cp_length elements | |
2305 // are copied from scratch_cp to a smaller constant pool and the | |
2306 // smaller constant pool is associated with scratch_class. | |
2307 void VM_RedefineClasses::set_new_constant_pool( | |
2308 instanceKlassHandle scratch_class, constantPoolHandle scratch_cp, | |
2309 int scratch_cp_length, bool shrink, TRAPS) { | |
2310 assert(!shrink || scratch_cp->length() >= scratch_cp_length, "sanity check"); | |
2311 | |
2312 if (shrink) { | |
2313 // scratch_cp is a merged constant pool and has enough space for a | |
2314 // worst case merge situation. We want to associate the minimum | |
2315 // sized constant pool with the klass to save space. | |
2316 constantPoolHandle smaller_cp(THREAD, | |
2317 oopFactory::new_constantPool(scratch_cp_length, THREAD)); | |
2318 // preserve orig_length() value in the smaller copy | |
2319 int orig_length = scratch_cp->orig_length(); | |
2320 assert(orig_length != 0, "sanity check"); | |
2321 smaller_cp->set_orig_length(orig_length); | |
2322 scratch_cp->copy_cp_to(1, scratch_cp_length - 1, smaller_cp, 1, THREAD); | |
2323 scratch_cp = smaller_cp; | |
2324 } | |
2325 | |
2326 // attach new constant pool to klass | |
2327 scratch_cp->set_pool_holder(scratch_class()); | |
2328 | |
2329 // attach klass to new constant pool | |
2330 scratch_class->set_constants(scratch_cp()); | |
2331 | |
2332 int i; // for portability | |
2333 | |
2334 // update each field in klass to use new constant pool indices as needed | |
2335 typeArrayHandle fields(THREAD, scratch_class->fields()); | |
2336 int n_fields = fields->length(); | |
2337 for (i = 0; i < n_fields; i += instanceKlass::next_offset) { | |
2338 jshort cur_index = fields->short_at(i + instanceKlass::name_index_offset); | |
2339 jshort new_index = find_new_index(cur_index); | |
2340 if (new_index != 0) { | |
2341 RC_TRACE_WITH_THREAD(0x00080000, THREAD, | |
2342 ("field-name_index change: %d to %d", cur_index, new_index)); | |
2343 fields->short_at_put(i + instanceKlass::name_index_offset, new_index); | |
2344 } | |
2345 cur_index = fields->short_at(i + instanceKlass::signature_index_offset); | |
2346 new_index = find_new_index(cur_index); | |
2347 if (new_index != 0) { | |
2348 RC_TRACE_WITH_THREAD(0x00080000, THREAD, | |
2349 ("field-signature_index change: %d to %d", cur_index, new_index)); | |
2350 fields->short_at_put(i + instanceKlass::signature_index_offset, | |
2351 new_index); | |
2352 } | |
2353 cur_index = fields->short_at(i + instanceKlass::initval_index_offset); | |
2354 new_index = find_new_index(cur_index); | |
2355 if (new_index != 0) { | |
2356 RC_TRACE_WITH_THREAD(0x00080000, THREAD, | |
2357 ("field-initval_index change: %d to %d", cur_index, new_index)); | |
2358 fields->short_at_put(i + instanceKlass::initval_index_offset, new_index); | |
2359 } | |
2360 cur_index = fields->short_at(i + instanceKlass::generic_signature_offset); | |
2361 new_index = find_new_index(cur_index); | |
2362 if (new_index != 0) { | |
2363 RC_TRACE_WITH_THREAD(0x00080000, THREAD, | |
2364 ("field-generic_signature change: %d to %d", cur_index, new_index)); | |
2365 fields->short_at_put(i + instanceKlass::generic_signature_offset, | |
2366 new_index); | |
2367 } | |
2368 } // end for each field | |
2369 | |
2370 // Update constant pool indices in the inner classes info to use | |
2371 // new constant indices as needed. The inner classes info is a | |
2372 // quadruple: | |
2373 // (inner_class_info, outer_class_info, inner_name, inner_access_flags) | |
2374 typeArrayOop inner_class_list = scratch_class->inner_classes(); | |
2375 int icl_length = (inner_class_list == NULL) ? 0 : inner_class_list->length(); | |
2376 if (icl_length > 0) { | |
2377 typeArrayHandle inner_class_list_h(THREAD, inner_class_list); | |
2378 for (int i = 0; i < icl_length; | |
2379 i += instanceKlass::inner_class_next_offset) { | |
2380 int cur_index = inner_class_list_h->ushort_at(i | |
2381 + instanceKlass::inner_class_inner_class_info_offset); | |
2382 if (cur_index == 0) { | |
2383 continue; // JVM spec. allows null inner class refs so skip it | |
2384 } | |
2385 int new_index = find_new_index(cur_index); | |
2386 if (new_index != 0) { | |
2387 RC_TRACE_WITH_THREAD(0x00080000, THREAD, | |
2388 ("inner_class_info change: %d to %d", cur_index, new_index)); | |
2389 inner_class_list_h->ushort_at_put(i | |
2390 + instanceKlass::inner_class_inner_class_info_offset, new_index); | |
2391 } | |
2392 cur_index = inner_class_list_h->ushort_at(i | |
2393 + instanceKlass::inner_class_outer_class_info_offset); | |
2394 new_index = find_new_index(cur_index); | |
2395 if (new_index != 0) { | |
2396 RC_TRACE_WITH_THREAD(0x00080000, THREAD, | |
2397 ("outer_class_info change: %d to %d", cur_index, new_index)); | |
2398 inner_class_list_h->ushort_at_put(i | |
2399 + instanceKlass::inner_class_outer_class_info_offset, new_index); | |
2400 } | |
2401 cur_index = inner_class_list_h->ushort_at(i | |
2402 + instanceKlass::inner_class_inner_name_offset); | |
2403 new_index = find_new_index(cur_index); | |
2404 if (new_index != 0) { | |
2405 RC_TRACE_WITH_THREAD(0x00080000, THREAD, | |
2406 ("inner_name change: %d to %d", cur_index, new_index)); | |
2407 inner_class_list_h->ushort_at_put(i | |
2408 + instanceKlass::inner_class_inner_name_offset, new_index); | |
2409 } | |
2410 } // end for each inner class | |
2411 } // end if we have inner classes | |
2412 | |
2413 // Attach each method in klass to the new constant pool and update | |
2414 // to use new constant pool indices as needed: | |
2415 objArrayHandle methods(THREAD, scratch_class->methods()); | |
2416 for (i = methods->length() - 1; i >= 0; i--) { | |
2417 methodHandle method(THREAD, (methodOop)methods->obj_at(i)); | |
2418 method->set_constants(scratch_cp()); | |
2419 | |
2420 int new_index = find_new_index(method->name_index()); | |
2421 if (new_index != 0) { | |
2422 RC_TRACE_WITH_THREAD(0x00080000, THREAD, | |
2423 ("method-name_index change: %d to %d", method->name_index(), | |
2424 new_index)); | |
2425 method->set_name_index(new_index); | |
2426 } | |
2427 new_index = find_new_index(method->signature_index()); | |
2428 if (new_index != 0) { | |
2429 RC_TRACE_WITH_THREAD(0x00080000, THREAD, | |
2430 ("method-signature_index change: %d to %d", | |
2431 method->signature_index(), new_index)); | |
2432 method->set_signature_index(new_index); | |
2433 } | |
2434 new_index = find_new_index(method->generic_signature_index()); | |
2435 if (new_index != 0) { | |
2436 RC_TRACE_WITH_THREAD(0x00080000, THREAD, | |
2437 ("method-generic_signature_index change: %d to %d", | |
2438 method->generic_signature_index(), new_index)); | |
2439 method->set_generic_signature_index(new_index); | |
2440 } | |
2441 | |
2442 // Update constant pool indices in the method's checked exception | |
2443 // table to use new constant indices as needed. | |
2444 int cext_length = method->checked_exceptions_length(); | |
2445 if (cext_length > 0) { | |
2446 CheckedExceptionElement * cext_table = | |
2447 method->checked_exceptions_start(); | |
2448 for (int j = 0; j < cext_length; j++) { | |
2449 int cur_index = cext_table[j].class_cp_index; | |
2450 int new_index = find_new_index(cur_index); | |
2451 if (new_index != 0) { | |
2452 RC_TRACE_WITH_THREAD(0x00080000, THREAD, | |
2453 ("cext-class_cp_index change: %d to %d", cur_index, new_index)); | |
2454 cext_table[j].class_cp_index = (u2)new_index; | |
2455 } | |
2456 } // end for each checked exception table entry | |
2457 } // end if there are checked exception table entries | |
2458 | |
2459 // Update each catch type index in the method's exception table | |
2460 // to use new constant pool indices as needed. The exception table | |
2461 // holds quadruple entries of the form: | |
2462 // (beg_bci, end_bci, handler_bci, klass_index) | |
2463 const int beg_bci_offset = 0; | |
2464 const int end_bci_offset = 1; | |
2465 const int handler_bci_offset = 2; | |
2466 const int klass_index_offset = 3; | |
2467 const int entry_size = 4; | |
2468 | |
2469 typeArrayHandle ex_table (THREAD, method->exception_table()); | |
2470 int ext_length = ex_table->length(); | |
2471 assert(ext_length % entry_size == 0, "exception table format has changed"); | |
2472 | |
2473 for (int j = 0; j < ext_length; j += entry_size) { | |
2474 int cur_index = ex_table->int_at(j + klass_index_offset); | |
2475 int new_index = find_new_index(cur_index); | |
2476 if (new_index != 0) { | |
2477 RC_TRACE_WITH_THREAD(0x00080000, THREAD, | |
2478 ("ext-klass_index change: %d to %d", cur_index, new_index)); | |
2479 ex_table->int_at_put(j + klass_index_offset, new_index); | |
2480 } | |
2481 } // end for each exception table entry | |
2482 | |
2483 // Update constant pool indices in the method's local variable | |
2484 // table to use new constant indices as needed. The local variable | |
2485 // table hold sextuple entries of the form: | |
2486 // (start_pc, length, name_index, descriptor_index, signature_index, slot) | |
2487 int lvt_length = method->localvariable_table_length(); | |
2488 if (lvt_length > 0) { | |
2489 LocalVariableTableElement * lv_table = | |
2490 method->localvariable_table_start(); | |
2491 for (int j = 0; j < lvt_length; j++) { | |
2492 int cur_index = lv_table[j].name_cp_index; | |
2493 int new_index = find_new_index(cur_index); | |
2494 if (new_index != 0) { | |
2495 RC_TRACE_WITH_THREAD(0x00080000, THREAD, | |
2496 ("lvt-name_cp_index change: %d to %d", cur_index, new_index)); | |
2497 lv_table[j].name_cp_index = (u2)new_index; | |
2498 } | |
2499 cur_index = lv_table[j].descriptor_cp_index; | |
2500 new_index = find_new_index(cur_index); | |
2501 if (new_index != 0) { | |
2502 RC_TRACE_WITH_THREAD(0x00080000, THREAD, | |
2503 ("lvt-descriptor_cp_index change: %d to %d", cur_index, | |
2504 new_index)); | |
2505 lv_table[j].descriptor_cp_index = (u2)new_index; | |
2506 } | |
2507 cur_index = lv_table[j].signature_cp_index; | |
2508 new_index = find_new_index(cur_index); | |
2509 if (new_index != 0) { | |
2510 RC_TRACE_WITH_THREAD(0x00080000, THREAD, | |
2511 ("lvt-signature_cp_index change: %d to %d", cur_index, new_index)); | |
2512 lv_table[j].signature_cp_index = (u2)new_index; | |
2513 } | |
2514 } // end for each local variable table entry | |
2515 } // end if there are local variable table entries | |
2516 | |
2517 rewrite_cp_refs_in_stack_map_table(method, THREAD); | |
2518 } // end for each method | |
2519 } // end set_new_constant_pool() | |
2520 | |
2521 | |
2522 // Unevolving classes may point to methods of the_class directly | |
2523 // from their constant pool caches, itables, and/or vtables. We | |
2524 // use the SystemDictionary::classes_do() facility and this helper | |
2525 // to fix up these pointers. | |
2526 // | |
2527 // Note: We currently don't support updating the vtable in | |
2528 // arrayKlassOops. See Open Issues in jvmtiRedefineClasses.hpp. | |
2529 void VM_RedefineClasses::adjust_cpool_cache_and_vtable(klassOop k_oop, | |
2530 oop initiating_loader, TRAPS) { | |
2531 Klass *k = k_oop->klass_part(); | |
2532 if (k->oop_is_instance()) { | |
2533 HandleMark hm(THREAD); | |
2534 instanceKlass *ik = (instanceKlass *) k; | |
2535 | |
2536 // HotSpot specific optimization! HotSpot does not currently | |
2537 // support delegation from the bootstrap class loader to a | |
2538 // user-defined class loader. This means that if the bootstrap | |
2539 // class loader is the initiating class loader, then it will also | |
2540 // be the defining class loader. This also means that classes | |
2541 // loaded by the bootstrap class loader cannot refer to classes | |
2542 // loaded by a user-defined class loader. Note: a user-defined | |
2543 // class loader can delegate to the bootstrap class loader. | |
2544 // | |
2545 // If the current class being redefined has a user-defined class | |
2546 // loader as its defining class loader, then we can skip all | |
2547 // classes loaded by the bootstrap class loader. | |
2548 bool is_user_defined = | |
2549 instanceKlass::cast(_the_class_oop)->class_loader() != NULL; | |
2550 if (is_user_defined && ik->class_loader() == NULL) { | |
2551 return; | |
2552 } | |
2553 | |
2554 // This is a very busy routine. We don't want too much tracing | |
2555 // printed out. | |
2556 bool trace_name_printed = false; | |
2557 | |
2558 // Very noisy: only enable this call if you are trying to determine | |
2559 // that a specific class gets found by this routine. | |
2560 // RC_TRACE macro has an embedded ResourceMark | |
2561 // RC_TRACE_WITH_THREAD(0x00100000, THREAD, | |
2562 // ("adjust check: name=%s", ik->external_name())); | |
2563 // trace_name_printed = true; | |
2564 | |
2565 // Fix the vtable embedded in the_class and subclasses of the_class, | |
2566 // if one exists. We discard scratch_class and we don't keep an | |
2567 // instanceKlass around to hold obsolete methods so we don't have | |
2568 // any other instanceKlass embedded vtables to update. The vtable | |
2569 // holds the methodOops for virtual (but not final) methods. | |
2570 if (ik->vtable_length() > 0 && ik->is_subtype_of(_the_class_oop)) { | |
2571 // ik->vtable() creates a wrapper object; rm cleans it up | |
2572 ResourceMark rm(THREAD); | |
2573 ik->vtable()->adjust_method_entries(_matching_old_methods, | |
2574 _matching_new_methods, | |
2575 _matching_methods_length, | |
2576 &trace_name_printed); | |
2577 } | |
2578 | |
2579 // If the current class has an itable and we are either redefining an | |
2580 // interface or if the current class is a subclass of the_class, then | |
2581 // we potentially have to fix the itable. If we are redefining an | |
2582 // interface, then we have to call adjust_method_entries() for | |
2583 // every instanceKlass that has an itable since there isn't a | |
2584 // subclass relationship between an interface and an instanceKlass. | |
2585 if (ik->itable_length() > 0 && (Klass::cast(_the_class_oop)->is_interface() | |
2586 || ik->is_subclass_of(_the_class_oop))) { | |
2587 // ik->itable() creates a wrapper object; rm cleans it up | |
2588 ResourceMark rm(THREAD); | |
2589 ik->itable()->adjust_method_entries(_matching_old_methods, | |
2590 _matching_new_methods, | |
2591 _matching_methods_length, | |
2592 &trace_name_printed); | |
2593 } | |
2594 | |
2595 // The constant pools in other classes (other_cp) can refer to | |
2596 // methods in the_class. We have to update method information in | |
2597 // other_cp's cache. If other_cp has a previous version, then we | |
2598 // have to repeat the process for each previous version. The | |
2599 // constant pool cache holds the methodOops for non-virtual | |
2600 // methods and for virtual, final methods. | |
2601 // | |
2602 // Special case: if the current class is the_class, then new_cp | |
2603 // has already been attached to the_class and old_cp has already | |
2604 // been added as a previous version. The new_cp doesn't have any | |
2605 // cached references to old methods so it doesn't need to be | |
2606 // updated. We can simply start with the previous version(s) in | |
2607 // that case. | |
2608 constantPoolHandle other_cp; | |
2609 constantPoolCacheOop cp_cache; | |
2610 | |
2611 if (k_oop != _the_class_oop) { | |
2612 // this klass' constant pool cache may need adjustment | |
2613 other_cp = constantPoolHandle(ik->constants()); | |
2614 cp_cache = other_cp->cache(); | |
2615 if (cp_cache != NULL) { | |
2616 cp_cache->adjust_method_entries(_matching_old_methods, | |
2617 _matching_new_methods, | |
2618 _matching_methods_length, | |
2619 &trace_name_printed); | |
2620 } | |
2621 } | |
2622 { | |
2623 ResourceMark rm(THREAD); | |
2624 // PreviousVersionInfo objects returned via PreviousVersionWalker | |
2625 // contain a GrowableArray of handles. We have to clean up the | |
2626 // GrowableArray _after_ the PreviousVersionWalker destructor | |
2627 // has destroyed the handles. | |
2628 { | |
2629 // the previous versions' constant pool caches may need adjustment | |
2630 PreviousVersionWalker pvw(ik); | |
2631 for (PreviousVersionInfo * pv_info = pvw.next_previous_version(); | |
2632 pv_info != NULL; pv_info = pvw.next_previous_version()) { | |
2633 other_cp = pv_info->prev_constant_pool_handle(); | |
2634 cp_cache = other_cp->cache(); | |
2635 if (cp_cache != NULL) { | |
2636 cp_cache->adjust_method_entries(_matching_old_methods, | |
2637 _matching_new_methods, | |
2638 _matching_methods_length, | |
2639 &trace_name_printed); | |
2640 } | |
2641 } | |
2642 } // pvw is cleaned up | |
2643 } // rm is cleaned up | |
2644 } | |
2645 } | |
2646 | |
2647 void VM_RedefineClasses::update_jmethod_ids() { | |
2648 for (int j = 0; j < _matching_methods_length; ++j) { | |
2649 methodOop old_method = _matching_old_methods[j]; | |
2650 jmethodID jmid = old_method->find_jmethod_id_or_null(); | |
2651 if (jmid != NULL) { | |
2652 // There is a jmethodID, change it to point to the new method | |
2653 methodHandle new_method_h(_matching_new_methods[j]); | |
2654 JNIHandles::change_method_associated_with_jmethod_id(jmid, new_method_h); | |
2655 assert(JNIHandles::resolve_jmethod_id(jmid) == _matching_new_methods[j], | |
2656 "should be replaced"); | |
2657 } | |
2658 } | |
2659 } | |
2660 | |
2661 void VM_RedefineClasses::check_methods_and_mark_as_obsolete( | |
2662 BitMap *emcp_methods, int * emcp_method_count_p) { | |
2663 *emcp_method_count_p = 0; | |
2664 int obsolete_count = 0; | |
2665 int old_index = 0; | |
2666 for (int j = 0; j < _matching_methods_length; ++j, ++old_index) { | |
2667 methodOop old_method = _matching_old_methods[j]; | |
2668 methodOop new_method = _matching_new_methods[j]; | |
2669 methodOop old_array_method; | |
2670 | |
2671 // Maintain an old_index into the _old_methods array by skipping | |
2672 // deleted methods | |
2673 while ((old_array_method = (methodOop) _old_methods->obj_at(old_index)) | |
2674 != old_method) { | |
2675 ++old_index; | |
2676 } | |
2677 | |
2678 if (MethodComparator::methods_EMCP(old_method, new_method)) { | |
2679 // The EMCP definition from JSR-163 requires the bytecodes to be | |
2680 // the same with the exception of constant pool indices which may | |
2681 // differ. However, the constants referred to by those indices | |
2682 // must be the same. | |
2683 // | |
2684 // We use methods_EMCP() for comparison since constant pool | |
2685 // merging can remove duplicate constant pool entries that were | |
2686 // present in the old method and removed from the rewritten new | |
2687 // method. A faster binary comparison function would consider the | |
2688 // old and new methods to be different when they are actually | |
2689 // EMCP. | |
2690 // | |
2691 // The old and new methods are EMCP and you would think that we | |
2692 // could get rid of one of them here and now and save some space. | |
2693 // However, the concept of EMCP only considers the bytecodes and | |
2694 // the constant pool entries in the comparison. Other things, | |
2695 // e.g., the line number table (LNT) or the local variable table | |
2696 // (LVT) don't count in the comparison. So the new (and EMCP) | |
2697 // method can have a new LNT that we need so we can't just | |
2698 // overwrite the new method with the old method. | |
2699 // | |
2700 // When this routine is called, we have already attached the new | |
2701 // methods to the_class so the old methods are effectively | |
2702 // overwritten. However, if an old method is still executing, | |
2703 // then the old method cannot be collected until sometime after | |
2704 // the old method call has returned. So the overwriting of old | |
2705 // methods by new methods will save us space except for those | |
2706 // (hopefully few) old methods that are still executing. | |
2707 // | |
2708 // A method refers to a constMethodOop and this presents another | |
2709 // possible avenue to space savings. The constMethodOop in the | |
2710 // new method contains possibly new attributes (LNT, LVT, etc). | |
2711 // At first glance, it seems possible to save space by replacing | |
2712 // the constMethodOop in the old method with the constMethodOop | |
2713 // from the new method. The old and new methods would share the | |
2714 // same constMethodOop and we would save the space occupied by | |
2715 // the old constMethodOop. However, the constMethodOop contains | |
2716 // a back reference to the containing method. Sharing the | |
2717 // constMethodOop between two methods could lead to confusion in | |
2718 // the code that uses the back reference. This would lead to | |
2719 // brittle code that could be broken in non-obvious ways now or | |
2720 // in the future. | |
2721 // | |
2722 // Another possibility is to copy the constMethodOop from the new | |
2723 // method to the old method and then overwrite the new method with | |
2724 // the old method. Since the constMethodOop contains the bytecodes | |
2725 // for the method embedded in the oop, this option would change | |
2726 // the bytecodes out from under any threads executing the old | |
2727 // method and make the thread's bcp invalid. Since EMCP requires | |
2728 // that the bytecodes be the same modulo constant pool indices, it | |
2729 // is straight forward to compute the correct new bcp in the new | |
2730 // constMethodOop from the old bcp in the old constMethodOop. The | |
2731 // time consuming part would be searching all the frames in all | |
2732 // of the threads to find all of the calls to the old method. | |
2733 // | |
2734 // It looks like we will have to live with the limited savings | |
2735 // that we get from effectively overwriting the old methods | |
2736 // when the new methods are attached to the_class. | |
2737 | |
2738 // track which methods are EMCP for add_previous_version() call | |
2739 emcp_methods->set_bit(old_index); | |
2740 (*emcp_method_count_p)++; | |
2741 | |
2742 // An EMCP method is _not_ obsolete. An obsolete method has a | |
2743 // different jmethodID than the current method. An EMCP method | |
2744 // has the same jmethodID as the current method. Having the | |
2745 // same jmethodID for all EMCP versions of a method allows for | |
2746 // a consistent view of the EMCP methods regardless of which | |
2747 // EMCP method you happen to have in hand. For example, a | |
2748 // breakpoint set in one EMCP method will work for all EMCP | |
2749 // versions of the method including the current one. | |
2750 } else { | |
2751 // mark obsolete methods as such | |
2752 old_method->set_is_obsolete(); | |
2753 obsolete_count++; | |
2754 | |
2755 // obsolete methods need a unique idnum | |
2756 u2 num = instanceKlass::cast(_the_class_oop)->next_method_idnum(); | |
2757 if (num != constMethodOopDesc::UNSET_IDNUM) { | |
2758 // u2 old_num = old_method->method_idnum(); | |
2759 old_method->set_method_idnum(num); | |
2760 // TO DO: attach obsolete annotations to obsolete method's new idnum | |
2761 } | |
2762 // With tracing we try not to "yack" too much. The position of | |
2763 // this trace assumes there are fewer obsolete methods than | |
2764 // EMCP methods. | |
2765 RC_TRACE(0x00000100, ("mark %s(%s) as obsolete", | |
2766 old_method->name()->as_C_string(), | |
2767 old_method->signature()->as_C_string())); | |
2768 } | |
2769 old_method->set_is_old(); | |
2770 } | |
2771 for (int i = 0; i < _deleted_methods_length; ++i) { | |
2772 methodOop old_method = _deleted_methods[i]; | |
2773 | |
2774 assert(old_method->vtable_index() < 0, | |
2775 "cannot delete methods with vtable entries");; | |
2776 | |
2777 // Mark all deleted methods as old and obsolete | |
2778 old_method->set_is_old(); | |
2779 old_method->set_is_obsolete(); | |
2780 ++obsolete_count; | |
2781 // With tracing we try not to "yack" too much. The position of | |
2782 // this trace assumes there are fewer obsolete methods than | |
2783 // EMCP methods. | |
2784 RC_TRACE(0x00000100, ("mark deleted %s(%s) as obsolete", | |
2785 old_method->name()->as_C_string(), | |
2786 old_method->signature()->as_C_string())); | |
2787 } | |
2788 assert((*emcp_method_count_p + obsolete_count) == _old_methods->length(), | |
2789 "sanity check"); | |
2790 RC_TRACE(0x00000100, ("EMCP_cnt=%d, obsolete_cnt=%d", *emcp_method_count_p, | |
2791 obsolete_count)); | |
2792 } | |
2793 | |
2794 // This internal class transfers the native function registration from old methods | |
2795 // to new methods. It is designed to handle both the simple case of unchanged | |
2796 // native methods and the complex cases of native method prefixes being added and/or | |
2797 // removed. | |
2798 // It expects only to be used during the VM_RedefineClasses op (a safepoint). | |
2799 // | |
2800 // This class is used after the new methods have been installed in "the_class". | |
2801 // | |
2802 // So, for example, the following must be handled. Where 'm' is a method and | |
2803 // a number followed by an underscore is a prefix. | |
2804 // | |
2805 // Old Name New Name | |
2806 // Simple transfer to new method m -> m | |
2807 // Add prefix m -> 1_m | |
2808 // Remove prefix 1_m -> m | |
2809 // Simultaneous add of prefixes m -> 3_2_1_m | |
2810 // Simultaneous removal of prefixes 3_2_1_m -> m | |
2811 // Simultaneous add and remove 1_m -> 2_m | |
2812 // Same, caused by prefix removal only 3_2_1_m -> 3_2_m | |
2813 // | |
2814 class TransferNativeFunctionRegistration { | |
2815 private: | |
2816 instanceKlassHandle the_class; | |
2817 int prefix_count; | |
2818 char** prefixes; | |
2819 | |
2820 // Recursively search the binary tree of possibly prefixed method names. | |
2821 // Iteration could be used if all agents were well behaved. Full tree walk is | |
2822 // more resilent to agents not cleaning up intermediate methods. | |
2823 // Branch at each depth in the binary tree is: | |
2824 // (1) without the prefix. | |
2825 // (2) with the prefix. | |
2826 // where 'prefix' is the prefix at that 'depth' (first prefix, second prefix,...) | |
2827 methodOop search_prefix_name_space(int depth, char* name_str, size_t name_len, | |
2828 symbolOop signature) { | |
2829 symbolOop name_symbol = SymbolTable::probe(name_str, (int)name_len); | |
2830 if (name_symbol != NULL) { | |
2831 methodOop method = Klass::cast(the_class())->lookup_method(name_symbol, signature); | |
2832 if (method != NULL) { | |
2833 // Even if prefixed, intermediate methods must exist. | |
2834 if (method->is_native()) { | |
2835 // Wahoo, we found a (possibly prefixed) version of the method, return it. | |
2836 return method; | |
2837 } | |
2838 if (depth < prefix_count) { | |
2839 // Try applying further prefixes (other than this one). | |
2840 method = search_prefix_name_space(depth+1, name_str, name_len, signature); | |
2841 if (method != NULL) { | |
2842 return method; // found | |
2843 } | |
2844 | |
2845 // Try adding this prefix to the method name and see if it matches | |
2846 // another method name. | |
2847 char* prefix = prefixes[depth]; | |
2848 size_t prefix_len = strlen(prefix); | |
2849 size_t trial_len = name_len + prefix_len; | |
2850 char* trial_name_str = NEW_RESOURCE_ARRAY(char, trial_len + 1); | |
2851 strcpy(trial_name_str, prefix); | |
2852 strcat(trial_name_str, name_str); | |
2853 method = search_prefix_name_space(depth+1, trial_name_str, trial_len, | |
2854 signature); | |
2855 if (method != NULL) { | |
2856 // If found along this branch, it was prefixed, mark as such | |
2857 method->set_is_prefixed_native(); | |
2858 return method; // found | |
2859 } | |
2860 } | |
2861 } | |
2862 } | |
2863 return NULL; // This whole branch bore nothing | |
2864 } | |
2865 | |
2866 // Return the method name with old prefixes stripped away. | |
2867 char* method_name_without_prefixes(methodOop method) { | |
2868 symbolOop name = method->name(); | |
2869 char* name_str = name->as_utf8(); | |
2870 | |
2871 // Old prefixing may be defunct, strip prefixes, if any. | |
2872 for (int i = prefix_count-1; i >= 0; i--) { | |
2873 char* prefix = prefixes[i]; | |
2874 size_t prefix_len = strlen(prefix); | |
2875 if (strncmp(prefix, name_str, prefix_len) == 0) { | |
2876 name_str += prefix_len; | |
2877 } | |
2878 } | |
2879 return name_str; | |
2880 } | |
2881 | |
2882 // Strip any prefixes off the old native method, then try to find a | |
2883 // (possibly prefixed) new native that matches it. | |
2884 methodOop strip_and_search_for_new_native(methodOop method) { | |
2885 ResourceMark rm; | |
2886 char* name_str = method_name_without_prefixes(method); | |
2887 return search_prefix_name_space(0, name_str, strlen(name_str), | |
2888 method->signature()); | |
2889 } | |
2890 | |
2891 public: | |
2892 | |
2893 // Construct a native method transfer processor for this class. | |
2894 TransferNativeFunctionRegistration(instanceKlassHandle _the_class) { | |
2895 assert(SafepointSynchronize::is_at_safepoint(), "sanity check"); | |
2896 | |
2897 the_class = _the_class; | |
2898 prefixes = JvmtiExport::get_all_native_method_prefixes(&prefix_count); | |
2899 } | |
2900 | |
2901 // Attempt to transfer any of the old or deleted methods that are native | |
2902 void transfer_registrations(methodOop* old_methods, int methods_length) { | |
2903 for (int j = 0; j < methods_length; j++) { | |
2904 methodOop old_method = old_methods[j]; | |
2905 | |
2906 if (old_method->is_native() && old_method->has_native_function()) { | |
2907 methodOop new_method = strip_and_search_for_new_native(old_method); | |
2908 if (new_method != NULL) { | |
2909 // Actually set the native function in the new method. | |
2910 // Redefine does not send events (except CFLH), certainly not this | |
2911 // behind the scenes re-registration. | |
2912 new_method->set_native_function(old_method->native_function(), | |
2913 !methodOopDesc::native_bind_event_is_interesting); | |
2914 } | |
2915 } | |
2916 } | |
2917 } | |
2918 }; | |
2919 | |
2920 // Don't lose the association between a native method and its JNI function. | |
2921 void VM_RedefineClasses::transfer_old_native_function_registrations(instanceKlassHandle the_class) { | |
2922 TransferNativeFunctionRegistration transfer(the_class); | |
2923 transfer.transfer_registrations(_deleted_methods, _deleted_methods_length); | |
2924 transfer.transfer_registrations(_matching_old_methods, _matching_methods_length); | |
2925 } | |
2926 | |
2927 // Deoptimize all compiled code that depends on this class. | |
2928 // | |
2929 // If the can_redefine_classes capability is obtained in the onload | |
2930 // phase then the compiler has recorded all dependencies from startup. | |
2931 // In that case we need only deoptimize and throw away all compiled code | |
2932 // that depends on the class. | |
2933 // | |
2934 // If can_redefine_classes is obtained sometime after the onload | |
2935 // phase then the dependency information may be incomplete. In that case | |
2936 // the first call to RedefineClasses causes all compiled code to be | |
2937 // thrown away. As can_redefine_classes has been obtained then | |
2938 // all future compilations will record dependencies so second and | |
2939 // subsequent calls to RedefineClasses need only throw away code | |
2940 // that depends on the class. | |
2941 // | |
2942 void VM_RedefineClasses::flush_dependent_code(instanceKlassHandle k_h, TRAPS) { | |
2943 assert_locked_or_safepoint(Compile_lock); | |
2944 | |
2945 // All dependencies have been recorded from startup or this is a second or | |
2946 // subsequent use of RedefineClasses | |
2947 if (JvmtiExport::all_dependencies_are_recorded()) { | |
2948 Universe::flush_evol_dependents_on(k_h); | |
2949 } else { | |
2950 CodeCache::mark_all_nmethods_for_deoptimization(); | |
2951 | |
2952 ResourceMark rm(THREAD); | |
2953 DeoptimizationMarker dm; | |
2954 | |
2955 // Deoptimize all activations depending on marked nmethods | |
2956 Deoptimization::deoptimize_dependents(); | |
2957 | |
2958 // Make the dependent methods not entrant (in VM_Deoptimize they are made zombies) | |
2959 CodeCache::make_marked_nmethods_not_entrant(); | |
2960 | |
2961 // From now on we know that the dependency information is complete | |
2962 JvmtiExport::set_all_dependencies_are_recorded(true); | |
2963 } | |
2964 } | |
2965 | |
2966 void VM_RedefineClasses::compute_added_deleted_matching_methods() { | |
2967 methodOop old_method; | |
2968 methodOop new_method; | |
2969 | |
2970 _matching_old_methods = NEW_RESOURCE_ARRAY(methodOop, _old_methods->length()); | |
2971 _matching_new_methods = NEW_RESOURCE_ARRAY(methodOop, _old_methods->length()); | |
2972 _added_methods = NEW_RESOURCE_ARRAY(methodOop, _new_methods->length()); | |
2973 _deleted_methods = NEW_RESOURCE_ARRAY(methodOop, _old_methods->length()); | |
2974 | |
2975 _matching_methods_length = 0; | |
2976 _deleted_methods_length = 0; | |
2977 _added_methods_length = 0; | |
2978 | |
2979 int nj = 0; | |
2980 int oj = 0; | |
2981 while (true) { | |
2982 if (oj >= _old_methods->length()) { | |
2983 if (nj >= _new_methods->length()) { | |
2984 break; // we've looked at everything, done | |
2985 } | |
2986 // New method at the end | |
2987 new_method = (methodOop) _new_methods->obj_at(nj); | |
2988 _added_methods[_added_methods_length++] = new_method; | |
2989 ++nj; | |
2990 } else if (nj >= _new_methods->length()) { | |
2991 // Old method, at the end, is deleted | |
2992 old_method = (methodOop) _old_methods->obj_at(oj); | |
2993 _deleted_methods[_deleted_methods_length++] = old_method; | |
2994 ++oj; | |
2995 } else { | |
2996 old_method = (methodOop) _old_methods->obj_at(oj); | |
2997 new_method = (methodOop) _new_methods->obj_at(nj); | |
2998 if (old_method->name() == new_method->name()) { | |
2999 if (old_method->signature() == new_method->signature()) { | |
3000 _matching_old_methods[_matching_methods_length ] = old_method; | |
3001 _matching_new_methods[_matching_methods_length++] = new_method; | |
3002 ++nj; | |
3003 ++oj; | |
3004 } else { | |
3005 // added overloaded have already been moved to the end, | |
3006 // so this is a deleted overloaded method | |
3007 _deleted_methods[_deleted_methods_length++] = old_method; | |
3008 ++oj; | |
3009 } | |
3010 } else { // names don't match | |
3011 if (old_method->name()->fast_compare(new_method->name()) > 0) { | |
3012 // new method | |
3013 _added_methods[_added_methods_length++] = new_method; | |
3014 ++nj; | |
3015 } else { | |
3016 // deleted method | |
3017 _deleted_methods[_deleted_methods_length++] = old_method; | |
3018 ++oj; | |
3019 } | |
3020 } | |
3021 } | |
3022 } | |
3023 assert(_matching_methods_length + _deleted_methods_length == _old_methods->length(), "sanity"); | |
3024 assert(_matching_methods_length + _added_methods_length == _new_methods->length(), "sanity"); | |
3025 } | |
3026 | |
3027 | |
3028 | |
3029 // Install the redefinition of a class: | |
3030 // - house keeping (flushing breakpoints and caches, deoptimizing | |
3031 // dependent compiled code) | |
3032 // - replacing parts in the_class with parts from scratch_class | |
3033 // - adding a weak reference to track the obsolete but interesting | |
3034 // parts of the_class | |
3035 // - adjusting constant pool caches and vtables in other classes | |
3036 // that refer to methods in the_class. These adjustments use the | |
3037 // SystemDictionary::classes_do() facility which only allows | |
3038 // a helper method to be specified. The interesting parameters | |
3039 // that we would like to pass to the helper method are saved in | |
3040 // static global fields in the VM operation. | |
3041 void VM_RedefineClasses::redefine_single_class(jclass the_jclass, | |
3042 instanceKlassHandle scratch_class, TRAPS) { | |
3043 | |
3044 RC_TIMER_START(_timer_rsc_phase1); | |
3045 | |
3046 oop the_class_mirror = JNIHandles::resolve_non_null(the_jclass); | |
3047 klassOop the_class_oop = java_lang_Class::as_klassOop(the_class_mirror); | |
3048 instanceKlassHandle the_class = instanceKlassHandle(THREAD, the_class_oop); | |
3049 | |
3050 #ifndef JVMTI_KERNEL | |
3051 // Remove all breakpoints in methods of this class | |
3052 JvmtiBreakpoints& jvmti_breakpoints = JvmtiCurrentBreakpoints::get_jvmti_breakpoints(); | |
3053 jvmti_breakpoints.clearall_in_class_at_safepoint(the_class_oop); | |
3054 #endif // !JVMTI_KERNEL | |
3055 | |
3056 if (the_class_oop == Universe::reflect_invoke_cache()->klass()) { | |
3057 // We are redefining java.lang.reflect.Method. Method.invoke() is | |
3058 // cached and users of the cache care about each active version of | |
3059 // the method so we have to track this previous version. | |
3060 // Do this before methods get switched | |
3061 Universe::reflect_invoke_cache()->add_previous_version( | |
3062 the_class->method_with_idnum(Universe::reflect_invoke_cache()->method_idnum())); | |
3063 } | |
3064 | |
3065 // Deoptimize all compiled code that depends on this class | |
3066 flush_dependent_code(the_class, THREAD); | |
3067 | |
3068 _old_methods = the_class->methods(); | |
3069 _new_methods = scratch_class->methods(); | |
3070 _the_class_oop = the_class_oop; | |
3071 compute_added_deleted_matching_methods(); | |
3072 update_jmethod_ids(); | |
3073 | |
3074 // Attach new constant pool to the original klass. The original | |
3075 // klass still refers to the old constant pool (for now). | |
3076 scratch_class->constants()->set_pool_holder(the_class()); | |
3077 | |
3078 #if 0 | |
3079 // In theory, with constant pool merging in place we should be able | |
3080 // to save space by using the new, merged constant pool in place of | |
3081 // the old constant pool(s). By "pool(s)" I mean the constant pool in | |
3082 // the klass version we are replacing now and any constant pool(s) in | |
3083 // previous versions of klass. Nice theory, doesn't work in practice. | |
3084 // When this code is enabled, even simple programs throw NullPointer | |
3085 // exceptions. I'm guessing that this is caused by some constant pool | |
3086 // cache difference between the new, merged constant pool and the | |
3087 // constant pool that was just being used by the klass. I'm keeping | |
3088 // this code around to archive the idea, but the code has to remain | |
3089 // disabled for now. | |
3090 | |
3091 // Attach each old method to the new constant pool. This can be | |
3092 // done here since we are past the bytecode verification and | |
3093 // constant pool optimization phases. | |
3094 for (int i = _old_methods->length() - 1; i >= 0; i--) { | |
3095 methodOop method = (methodOop)_old_methods->obj_at(i); | |
3096 method->set_constants(scratch_class->constants()); | |
3097 } | |
3098 | |
3099 { | |
3100 // walk all previous versions of the klass | |
3101 instanceKlass *ik = (instanceKlass *)the_class()->klass_part(); | |
3102 PreviousVersionWalker pvw(ik); | |
3103 instanceKlassHandle ikh; | |
3104 do { | |
3105 ikh = pvw.next_previous_version(); | |
3106 if (!ikh.is_null()) { | |
3107 ik = ikh(); | |
3108 | |
3109 // attach previous version of klass to the new constant pool | |
3110 ik->set_constants(scratch_class->constants()); | |
3111 | |
3112 // Attach each method in the previous version of klass to the | |
3113 // new constant pool | |
3114 objArrayOop prev_methods = ik->methods(); | |
3115 for (int i = prev_methods->length() - 1; i >= 0; i--) { | |
3116 methodOop method = (methodOop)prev_methods->obj_at(i); | |
3117 method->set_constants(scratch_class->constants()); | |
3118 } | |
3119 } | |
3120 } while (!ikh.is_null()); | |
3121 } | |
3122 #endif | |
3123 | |
3124 // Replace methods and constantpool | |
3125 the_class->set_methods(_new_methods); | |
3126 scratch_class->set_methods(_old_methods); // To prevent potential GCing of the old methods, | |
3127 // and to be able to undo operation easily. | |
3128 | |
3129 constantPoolOop old_constants = the_class->constants(); | |
3130 the_class->set_constants(scratch_class->constants()); | |
3131 scratch_class->set_constants(old_constants); // See the previous comment. | |
3132 #if 0 | |
3133 // We are swapping the guts of "the new class" with the guts of "the | |
3134 // class". Since the old constant pool has just been attached to "the | |
3135 // new class", it seems logical to set the pool holder in the old | |
3136 // constant pool also. However, doing this will change the observable | |
3137 // class hierarchy for any old methods that are still executing. A | |
3138 // method can query the identity of its "holder" and this query uses | |
3139 // the method's constant pool link to find the holder. The change in | |
3140 // holding class from "the class" to "the new class" can confuse | |
3141 // things. | |
3142 // | |
3143 // Setting the old constant pool's holder will also cause | |
3144 // verification done during vtable initialization below to fail. | |
3145 // During vtable initialization, the vtable's class is verified to be | |
3146 // a subtype of the method's holder. The vtable's class is "the | |
3147 // class" and the method's holder is gotten from the constant pool | |
3148 // link in the method itself. For "the class"'s directly implemented | |
3149 // methods, the method holder is "the class" itself (as gotten from | |
3150 // the new constant pool). The check works fine in this case. The | |
3151 // check also works fine for methods inherited from super classes. | |
3152 // | |
3153 // Miranda methods are a little more complicated. A miranda method is | |
3154 // provided by an interface when the class implementing the interface | |
3155 // does not provide its own method. These interfaces are implemented | |
3156 // internally as an instanceKlass. These special instanceKlasses | |
3157 // share the constant pool of the class that "implements" the | |
3158 // interface. By sharing the constant pool, the method holder of a | |
3159 // miranda method is the class that "implements" the interface. In a | |
3160 // non-redefine situation, the subtype check works fine. However, if | |
3161 // the old constant pool's pool holder is modified, then the check | |
3162 // fails because there is no class hierarchy relationship between the | |
3163 // vtable's class and "the new class". | |
3164 | |
3165 old_constants->set_pool_holder(scratch_class()); | |
3166 #endif | |
3167 | |
3168 // track which methods are EMCP for add_previous_version() call below | |
3169 BitMap emcp_methods(_old_methods->length()); | |
3170 int emcp_method_count = 0; | |
3171 emcp_methods.clear(); // clears 0..(length() - 1) | |
3172 check_methods_and_mark_as_obsolete(&emcp_methods, &emcp_method_count); | |
3173 transfer_old_native_function_registrations(the_class); | |
3174 | |
3175 // The class file bytes from before any retransformable agents mucked | |
3176 // with them was cached on the scratch class, move to the_class. | |
3177 // Note: we still want to do this if nothing needed caching since it | |
3178 // should get cleared in the_class too. | |
3179 the_class->set_cached_class_file(scratch_class->get_cached_class_file_bytes(), | |
3180 scratch_class->get_cached_class_file_len()); | |
3181 | |
3182 // Replace inner_classes | |
3183 typeArrayOop old_inner_classes = the_class->inner_classes(); | |
3184 the_class->set_inner_classes(scratch_class->inner_classes()); | |
3185 scratch_class->set_inner_classes(old_inner_classes); | |
3186 | |
3187 // Initialize the vtable and interface table after | |
3188 // methods have been rewritten | |
3189 { | |
3190 ResourceMark rm(THREAD); | |
3191 // no exception should happen here since we explicitly | |
3192 // do not check loader constraints. | |
3193 // compare_and_normalize_class_versions has already checked: | |
3194 // - classloaders unchanged, signatures unchanged | |
3195 // - all instanceKlasses for redefined classes reused & contents updated | |
3196 the_class->vtable()->initialize_vtable(false, THREAD); | |
3197 the_class->itable()->initialize_itable(false, THREAD); | |
3198 assert(!HAS_PENDING_EXCEPTION || (THREAD->pending_exception()->is_a(SystemDictionary::threaddeath_klass())), "redefine exception"); | |
3199 } | |
3200 | |
3201 // Leave arrays of jmethodIDs and itable index cache unchanged | |
3202 | |
3203 // Copy the "source file name" attribute from new class version | |
3204 the_class->set_source_file_name(scratch_class->source_file_name()); | |
3205 | |
3206 // Copy the "source debug extension" attribute from new class version | |
3207 the_class->set_source_debug_extension( | |
3208 scratch_class->source_debug_extension()); | |
3209 | |
3210 // Use of javac -g could be different in the old and the new | |
3211 if (scratch_class->access_flags().has_localvariable_table() != | |
3212 the_class->access_flags().has_localvariable_table()) { | |
3213 | |
3214 AccessFlags flags = the_class->access_flags(); | |
3215 if (scratch_class->access_flags().has_localvariable_table()) { | |
3216 flags.set_has_localvariable_table(); | |
3217 } else { | |
3218 flags.clear_has_localvariable_table(); | |
3219 } | |
3220 the_class->set_access_flags(flags); | |
3221 } | |
3222 | |
3223 // Replace class annotation fields values | |
3224 typeArrayOop old_class_annotations = the_class->class_annotations(); | |
3225 the_class->set_class_annotations(scratch_class->class_annotations()); | |
3226 scratch_class->set_class_annotations(old_class_annotations); | |
3227 | |
3228 // Replace fields annotation fields values | |
3229 objArrayOop old_fields_annotations = the_class->fields_annotations(); | |
3230 the_class->set_fields_annotations(scratch_class->fields_annotations()); | |
3231 scratch_class->set_fields_annotations(old_fields_annotations); | |
3232 | |
3233 // Replace methods annotation fields values | |
3234 objArrayOop old_methods_annotations = the_class->methods_annotations(); | |
3235 the_class->set_methods_annotations(scratch_class->methods_annotations()); | |
3236 scratch_class->set_methods_annotations(old_methods_annotations); | |
3237 | |
3238 // Replace methods parameter annotation fields values | |
3239 objArrayOop old_methods_parameter_annotations = | |
3240 the_class->methods_parameter_annotations(); | |
3241 the_class->set_methods_parameter_annotations( | |
3242 scratch_class->methods_parameter_annotations()); | |
3243 scratch_class->set_methods_parameter_annotations(old_methods_parameter_annotations); | |
3244 | |
3245 // Replace methods default annotation fields values | |
3246 objArrayOop old_methods_default_annotations = | |
3247 the_class->methods_default_annotations(); | |
3248 the_class->set_methods_default_annotations( | |
3249 scratch_class->methods_default_annotations()); | |
3250 scratch_class->set_methods_default_annotations(old_methods_default_annotations); | |
3251 | |
3252 // Replace minor version number of class file | |
3253 u2 old_minor_version = the_class->minor_version(); | |
3254 the_class->set_minor_version(scratch_class->minor_version()); | |
3255 scratch_class->set_minor_version(old_minor_version); | |
3256 | |
3257 // Replace major version number of class file | |
3258 u2 old_major_version = the_class->major_version(); | |
3259 the_class->set_major_version(scratch_class->major_version()); | |
3260 scratch_class->set_major_version(old_major_version); | |
3261 | |
3262 // Replace CP indexes for class and name+type of enclosing method | |
3263 u2 old_class_idx = the_class->enclosing_method_class_index(); | |
3264 u2 old_method_idx = the_class->enclosing_method_method_index(); | |
3265 the_class->set_enclosing_method_indices( | |
3266 scratch_class->enclosing_method_class_index(), | |
3267 scratch_class->enclosing_method_method_index()); | |
3268 scratch_class->set_enclosing_method_indices(old_class_idx, old_method_idx); | |
3269 | |
3270 // keep track of previous versions of this class | |
3271 the_class->add_previous_version(scratch_class, &emcp_methods, | |
3272 emcp_method_count); | |
3273 | |
3274 RC_TIMER_STOP(_timer_rsc_phase1); | |
3275 RC_TIMER_START(_timer_rsc_phase2); | |
3276 | |
3277 // Adjust constantpool caches and vtables for all classes | |
3278 // that reference methods of the evolved class. | |
3279 SystemDictionary::classes_do(adjust_cpool_cache_and_vtable, THREAD); | |
3280 | |
3281 if (the_class->oop_map_cache() != NULL) { | |
3282 // Flush references to any obsolete methods from the oop map cache | |
3283 // so that obsolete methods are not pinned. | |
3284 the_class->oop_map_cache()->flush_obsolete_entries(); | |
3285 } | |
3286 | |
3287 // increment the classRedefinedCount field in the_class and in any | |
3288 // direct and indirect subclasses of the_class | |
3289 increment_class_counter((instanceKlass *)the_class()->klass_part(), THREAD); | |
3290 | |
3291 // RC_TRACE macro has an embedded ResourceMark | |
3292 RC_TRACE_WITH_THREAD(0x00000001, THREAD, | |
3293 ("redefined name=%s, count=%d (avail_mem=" UINT64_FORMAT "K)", | |
3294 the_class->external_name(), | |
3295 java_lang_Class::classRedefinedCount(the_class_mirror), | |
3296 os::available_memory() >> 10)); | |
3297 | |
3298 RC_TIMER_STOP(_timer_rsc_phase2); | |
3299 } // end redefine_single_class() | |
3300 | |
3301 | |
3302 // Increment the classRedefinedCount field in the specific instanceKlass | |
3303 // and in all direct and indirect subclasses. | |
3304 void VM_RedefineClasses::increment_class_counter(instanceKlass *ik, TRAPS) { | |
3305 oop class_mirror = ik->java_mirror(); | |
3306 klassOop class_oop = java_lang_Class::as_klassOop(class_mirror); | |
3307 int new_count = java_lang_Class::classRedefinedCount(class_mirror) + 1; | |
3308 java_lang_Class::set_classRedefinedCount(class_mirror, new_count); | |
3309 | |
3310 if (class_oop != _the_class_oop) { | |
3311 // _the_class_oop count is printed at end of redefine_single_class() | |
3312 RC_TRACE_WITH_THREAD(0x00000008, THREAD, | |
3313 ("updated count in subclass=%s to %d", ik->external_name(), new_count)); | |
3314 } | |
3315 | |
3316 for (Klass *subk = ik->subklass(); subk != NULL; | |
3317 subk = subk->next_sibling()) { | |
3318 klassOop sub = subk->as_klassOop(); | |
3319 instanceKlass *subik = (instanceKlass *)sub->klass_part(); | |
3320 | |
3321 // recursively do subclasses of the current subclass | |
3322 increment_class_counter(subik, THREAD); | |
3323 } | |
3324 } | |
3325 | |
3326 #ifndef PRODUCT | |
3327 void VM_RedefineClasses::check_class(klassOop k_oop, | |
3328 oop initiating_loader, TRAPS) { | |
3329 Klass *k = k_oop->klass_part(); | |
3330 if (k->oop_is_instance()) { | |
3331 HandleMark hm(THREAD); | |
3332 instanceKlass *ik = (instanceKlass *) k; | |
3333 | |
3334 if (ik->vtable_length() > 0) { | |
3335 ResourceMark rm(THREAD); | |
3336 if (!ik->vtable()->check_no_old_entries()) { | |
3337 tty->print_cr("klassVtable::check_no_old_entries failure -- OLD method found -- class: %s", ik->signature_name()); | |
3338 ik->vtable()->dump_vtable(); | |
3339 dump_methods(); | |
3340 assert(false, "OLD method found"); | |
3341 } | |
3342 } | |
3343 } | |
3344 } | |
3345 | |
3346 void VM_RedefineClasses::dump_methods() { | |
3347 int j; | |
3348 tty->print_cr("_old_methods --"); | |
3349 for (j = 0; j < _old_methods->length(); ++j) { | |
3350 methodOop m = (methodOop) _old_methods->obj_at(j); | |
3351 tty->print("%4d (%5d) ", j, m->vtable_index()); | |
3352 m->access_flags().print_on(tty); | |
3353 tty->print(" -- "); | |
3354 m->print_name(tty); | |
3355 tty->cr(); | |
3356 } | |
3357 tty->print_cr("_new_methods --"); | |
3358 for (j = 0; j < _new_methods->length(); ++j) { | |
3359 methodOop m = (methodOop) _new_methods->obj_at(j); | |
3360 tty->print("%4d (%5d) ", j, m->vtable_index()); | |
3361 m->access_flags().print_on(tty); | |
3362 tty->print(" -- "); | |
3363 m->print_name(tty); | |
3364 tty->cr(); | |
3365 } | |
3366 tty->print_cr("_matching_(old/new)_methods --"); | |
3367 for (j = 0; j < _matching_methods_length; ++j) { | |
3368 methodOop m = _matching_old_methods[j]; | |
3369 tty->print("%4d (%5d) ", j, m->vtable_index()); | |
3370 m->access_flags().print_on(tty); | |
3371 tty->print(" -- "); | |
3372 m->print_name(tty); | |
3373 tty->cr(); | |
3374 m = _matching_new_methods[j]; | |
3375 tty->print(" (%5d) ", m->vtable_index()); | |
3376 m->access_flags().print_on(tty); | |
3377 tty->cr(); | |
3378 } | |
3379 tty->print_cr("_deleted_methods --"); | |
3380 for (j = 0; j < _deleted_methods_length; ++j) { | |
3381 methodOop m = _deleted_methods[j]; | |
3382 tty->print("%4d (%5d) ", j, m->vtable_index()); | |
3383 m->access_flags().print_on(tty); | |
3384 tty->print(" -- "); | |
3385 m->print_name(tty); | |
3386 tty->cr(); | |
3387 } | |
3388 tty->print_cr("_added_methods --"); | |
3389 for (j = 0; j < _added_methods_length; ++j) { | |
3390 methodOop m = _added_methods[j]; | |
3391 tty->print("%4d (%5d) ", j, m->vtable_index()); | |
3392 m->access_flags().print_on(tty); | |
3393 tty->print(" -- "); | |
3394 m->print_name(tty); | |
3395 tty->cr(); | |
3396 } | |
3397 } | |
3398 #endif |