Mercurial > hg > truffle
annotate src/share/vm/prims/jvmtiTagMap.cpp @ 909:b32a809aab08
6866585: debug code in ciObjectFactory too slow for large objects
Reviewed-by: ysr, never, kvn
author | jcoomes |
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date | Tue, 11 Aug 2009 23:24:41 -0700 |
parents | 0fbdb4381b99 |
children | 148e5441d916 |
rev | line source |
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0 | 1 /* |
579 | 2 * Copyright 2003-2009 Sun Microsystems, Inc. All Rights Reserved. |
0 | 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/_jvmtiTagMap.cpp.incl" | |
27 | |
28 // JvmtiTagHashmapEntry | |
29 // | |
30 // Each entry encapsulates a JNI weak reference to the tagged object | |
31 // and the tag value. In addition an entry includes a next pointer which | |
32 // is used to chain entries together. | |
33 | |
34 class JvmtiTagHashmapEntry : public CHeapObj { | |
35 private: | |
36 friend class JvmtiTagMap; | |
37 | |
38 jweak _object; // JNI weak ref to tagged object | |
39 jlong _tag; // the tag | |
40 JvmtiTagHashmapEntry* _next; // next on the list | |
41 | |
42 inline void init(jweak object, jlong tag) { | |
43 _object = object; | |
44 _tag = tag; | |
45 _next = NULL; | |
46 } | |
47 | |
48 // constructor | |
49 JvmtiTagHashmapEntry(jweak object, jlong tag) { init(object, tag); } | |
50 | |
51 public: | |
52 | |
53 // accessor methods | |
54 inline jweak object() const { return _object; } | |
55 inline jlong tag() const { return _tag; } | |
56 | |
57 inline void set_tag(jlong tag) { | |
58 assert(tag != 0, "can't be zero"); | |
59 _tag = tag; | |
60 } | |
61 | |
62 inline JvmtiTagHashmapEntry* next() const { return _next; } | |
63 inline void set_next(JvmtiTagHashmapEntry* next) { _next = next; } | |
64 }; | |
65 | |
66 | |
67 // JvmtiTagHashmap | |
68 // | |
69 // A hashmap is essentially a table of pointers to entries. Entries | |
70 // are hashed to a location, or position in the table, and then | |
71 // chained from that location. The "key" for hashing is address of | |
72 // the object, or oop. The "value" is the JNI weak reference to the | |
73 // object and the tag value. Keys are not stored with the entry. | |
74 // Instead the weak reference is resolved to obtain the key. | |
75 // | |
76 // A hashmap maintains a count of the number entries in the hashmap | |
77 // and resizes if the number of entries exceeds a given threshold. | |
78 // The threshold is specified as a percentage of the size - for | |
79 // example a threshold of 0.75 will trigger the hashmap to resize | |
80 // if the number of entries is >75% of table size. | |
81 // | |
82 // A hashmap provides functions for adding, removing, and finding | |
83 // entries. It also provides a function to iterate over all entries | |
84 // in the hashmap. | |
85 | |
86 class JvmtiTagHashmap : public CHeapObj { | |
87 private: | |
88 friend class JvmtiTagMap; | |
89 | |
90 enum { | |
91 small_trace_threshold = 10000, // threshold for tracing | |
92 medium_trace_threshold = 100000, | |
93 large_trace_threshold = 1000000, | |
94 initial_trace_threshold = small_trace_threshold | |
95 }; | |
96 | |
97 static int _sizes[]; // array of possible hashmap sizes | |
98 int _size; // actual size of the table | |
99 int _size_index; // index into size table | |
100 | |
101 int _entry_count; // number of entries in the hashmap | |
102 | |
103 float _load_factor; // load factor as a % of the size | |
104 int _resize_threshold; // computed threshold to trigger resizing. | |
105 bool _resizing_enabled; // indicates if hashmap can resize | |
106 | |
107 int _trace_threshold; // threshold for trace messages | |
108 | |
109 JvmtiTagHashmapEntry** _table; // the table of entries. | |
110 | |
111 // private accessors | |
112 int resize_threshold() const { return _resize_threshold; } | |
113 int trace_threshold() const { return _trace_threshold; } | |
114 | |
115 // initialize the hashmap | |
116 void init(int size_index=0, float load_factor=4.0f) { | |
117 int initial_size = _sizes[size_index]; | |
118 _size_index = size_index; | |
119 _size = initial_size; | |
120 _entry_count = 0; | |
121 if (TraceJVMTIObjectTagging) { | |
122 _trace_threshold = initial_trace_threshold; | |
123 } else { | |
124 _trace_threshold = -1; | |
125 } | |
126 _load_factor = load_factor; | |
127 _resize_threshold = (int)(_load_factor * _size); | |
128 _resizing_enabled = true; | |
129 size_t s = initial_size * sizeof(JvmtiTagHashmapEntry*); | |
130 _table = (JvmtiTagHashmapEntry**)os::malloc(s); | |
131 if (_table == NULL) { | |
132 vm_exit_out_of_memory(s, "unable to allocate initial hashtable for jvmti object tags"); | |
133 } | |
134 for (int i=0; i<initial_size; i++) { | |
135 _table[i] = NULL; | |
136 } | |
137 } | |
138 | |
139 // hash a given key (oop) with the specified size | |
140 static unsigned int hash(oop key, int size) { | |
141 // shift right to get better distribution (as these bits will be zero | |
142 // with aligned addresses) | |
143 unsigned int addr = (unsigned int)((intptr_t)key); | |
144 #ifdef _LP64 | |
145 return (addr >> 3) % size; | |
146 #else | |
147 return (addr >> 2) % size; | |
148 #endif | |
149 } | |
150 | |
151 // hash a given key (oop) | |
152 unsigned int hash(oop key) { | |
153 return hash(key, _size); | |
154 } | |
155 | |
156 // resize the hashmap - allocates a large table and re-hashes | |
157 // all entries into the new table. | |
158 void resize() { | |
159 int new_size_index = _size_index+1; | |
160 int new_size = _sizes[new_size_index]; | |
161 if (new_size < 0) { | |
162 // hashmap already at maximum capacity | |
163 return; | |
164 } | |
165 | |
166 // allocate new table | |
167 size_t s = new_size * sizeof(JvmtiTagHashmapEntry*); | |
168 JvmtiTagHashmapEntry** new_table = (JvmtiTagHashmapEntry**)os::malloc(s); | |
169 if (new_table == NULL) { | |
170 warning("unable to allocate larger hashtable for jvmti object tags"); | |
171 set_resizing_enabled(false); | |
172 return; | |
173 } | |
174 | |
175 // initialize new table | |
176 int i; | |
177 for (i=0; i<new_size; i++) { | |
178 new_table[i] = NULL; | |
179 } | |
180 | |
181 // rehash all entries into the new table | |
182 for (i=0; i<_size; i++) { | |
183 JvmtiTagHashmapEntry* entry = _table[i]; | |
184 while (entry != NULL) { | |
185 JvmtiTagHashmapEntry* next = entry->next(); | |
186 oop key = JNIHandles::resolve(entry->object()); | |
187 assert(key != NULL, "jni weak reference cleared!!"); | |
188 unsigned int h = hash(key, new_size); | |
189 JvmtiTagHashmapEntry* anchor = new_table[h]; | |
190 if (anchor == NULL) { | |
191 new_table[h] = entry; | |
192 entry->set_next(NULL); | |
193 } else { | |
194 entry->set_next(anchor); | |
195 new_table[h] = entry; | |
196 } | |
197 entry = next; | |
198 } | |
199 } | |
200 | |
201 // free old table and update settings. | |
202 os::free((void*)_table); | |
203 _table = new_table; | |
204 _size_index = new_size_index; | |
205 _size = new_size; | |
206 | |
207 // compute new resize threshold | |
208 _resize_threshold = (int)(_load_factor * _size); | |
209 } | |
210 | |
211 | |
212 // internal remove function - remove an entry at a given position in the | |
213 // table. | |
214 inline void remove(JvmtiTagHashmapEntry* prev, int pos, JvmtiTagHashmapEntry* entry) { | |
215 assert(pos >= 0 && pos < _size, "out of range"); | |
216 if (prev == NULL) { | |
217 _table[pos] = entry->next(); | |
218 } else { | |
219 prev->set_next(entry->next()); | |
220 } | |
221 assert(_entry_count > 0, "checking"); | |
222 _entry_count--; | |
223 } | |
224 | |
225 // resizing switch | |
226 bool is_resizing_enabled() const { return _resizing_enabled; } | |
227 void set_resizing_enabled(bool enable) { _resizing_enabled = enable; } | |
228 | |
229 // debugging | |
230 void print_memory_usage(); | |
231 void compute_next_trace_threshold(); | |
232 | |
233 public: | |
234 | |
235 // create a JvmtiTagHashmap of a preferred size and optionally a load factor. | |
236 // The preferred size is rounded down to an actual size. | |
237 JvmtiTagHashmap(int size, float load_factor=0.0f) { | |
238 int i=0; | |
239 while (_sizes[i] < size) { | |
240 if (_sizes[i] < 0) { | |
241 assert(i > 0, "sanity check"); | |
242 i--; | |
243 break; | |
244 } | |
245 i++; | |
246 } | |
247 | |
248 // if a load factor is specified then use it, otherwise use default | |
249 if (load_factor > 0.01f) { | |
250 init(i, load_factor); | |
251 } else { | |
252 init(i); | |
253 } | |
254 } | |
255 | |
256 // create a JvmtiTagHashmap with default settings | |
257 JvmtiTagHashmap() { | |
258 init(); | |
259 } | |
260 | |
261 // release table when JvmtiTagHashmap destroyed | |
262 ~JvmtiTagHashmap() { | |
263 if (_table != NULL) { | |
264 os::free((void*)_table); | |
265 _table = NULL; | |
266 } | |
267 } | |
268 | |
269 // accessors | |
270 int size() const { return _size; } | |
271 JvmtiTagHashmapEntry** table() const { return _table; } | |
272 int entry_count() const { return _entry_count; } | |
273 | |
274 // find an entry in the hashmap, returns NULL if not found. | |
275 inline JvmtiTagHashmapEntry* find(oop key) { | |
276 unsigned int h = hash(key); | |
277 JvmtiTagHashmapEntry* entry = _table[h]; | |
278 while (entry != NULL) { | |
279 oop orig_key = JNIHandles::resolve(entry->object()); | |
280 assert(orig_key != NULL, "jni weak reference cleared!!"); | |
281 if (key == orig_key) { | |
282 break; | |
283 } | |
284 entry = entry->next(); | |
285 } | |
286 return entry; | |
287 } | |
288 | |
289 | |
290 // add a new entry to hashmap | |
291 inline void add(oop key, JvmtiTagHashmapEntry* entry) { | |
292 assert(key != NULL, "checking"); | |
293 assert(find(key) == NULL, "duplicate detected"); | |
294 unsigned int h = hash(key); | |
295 JvmtiTagHashmapEntry* anchor = _table[h]; | |
296 if (anchor == NULL) { | |
297 _table[h] = entry; | |
298 entry->set_next(NULL); | |
299 } else { | |
300 entry->set_next(anchor); | |
301 _table[h] = entry; | |
302 } | |
303 | |
304 _entry_count++; | |
305 if (trace_threshold() > 0 && entry_count() >= trace_threshold()) { | |
306 assert(TraceJVMTIObjectTagging, "should only get here when tracing"); | |
307 print_memory_usage(); | |
308 compute_next_trace_threshold(); | |
309 } | |
310 | |
311 // if the number of entries exceed the threshold then resize | |
312 if (entry_count() > resize_threshold() && is_resizing_enabled()) { | |
313 resize(); | |
314 } | |
315 } | |
316 | |
317 // remove an entry with the given key. | |
318 inline JvmtiTagHashmapEntry* remove(oop key) { | |
319 unsigned int h = hash(key); | |
320 JvmtiTagHashmapEntry* entry = _table[h]; | |
321 JvmtiTagHashmapEntry* prev = NULL; | |
322 while (entry != NULL) { | |
323 oop orig_key = JNIHandles::resolve(entry->object()); | |
324 assert(orig_key != NULL, "jni weak reference cleared!!"); | |
325 if (key == orig_key) { | |
326 break; | |
327 } | |
328 prev = entry; | |
329 entry = entry->next(); | |
330 } | |
331 if (entry != NULL) { | |
332 remove(prev, h, entry); | |
333 } | |
334 return entry; | |
335 } | |
336 | |
337 // iterate over all entries in the hashmap | |
338 void entry_iterate(JvmtiTagHashmapEntryClosure* closure); | |
339 }; | |
340 | |
341 // possible hashmap sizes - odd primes that roughly double in size. | |
342 // To avoid excessive resizing the odd primes from 4801-76831 and | |
343 // 76831-307261 have been removed. The list must be terminated by -1. | |
344 int JvmtiTagHashmap::_sizes[] = { 4801, 76831, 307261, 614563, 1228891, | |
345 2457733, 4915219, 9830479, 19660831, 39321619, 78643219, -1 }; | |
346 | |
347 | |
348 // A supporting class for iterating over all entries in Hashmap | |
349 class JvmtiTagHashmapEntryClosure { | |
350 public: | |
351 virtual void do_entry(JvmtiTagHashmapEntry* entry) = 0; | |
352 }; | |
353 | |
354 | |
355 // iterate over all entries in the hashmap | |
356 void JvmtiTagHashmap::entry_iterate(JvmtiTagHashmapEntryClosure* closure) { | |
357 for (int i=0; i<_size; i++) { | |
358 JvmtiTagHashmapEntry* entry = _table[i]; | |
359 JvmtiTagHashmapEntry* prev = NULL; | |
360 while (entry != NULL) { | |
361 // obtain the next entry before invoking do_entry - this is | |
362 // necessary because do_entry may remove the entry from the | |
363 // hashmap. | |
364 JvmtiTagHashmapEntry* next = entry->next(); | |
365 closure->do_entry(entry); | |
366 entry = next; | |
367 } | |
368 } | |
369 } | |
370 | |
371 // debugging | |
372 void JvmtiTagHashmap::print_memory_usage() { | |
373 intptr_t p = (intptr_t)this; | |
374 tty->print("[JvmtiTagHashmap @ " INTPTR_FORMAT, p); | |
375 | |
376 // table + entries in KB | |
377 int hashmap_usage = (size()*sizeof(JvmtiTagHashmapEntry*) + | |
378 entry_count()*sizeof(JvmtiTagHashmapEntry))/K; | |
379 | |
380 int weak_globals_usage = (int)(JNIHandles::weak_global_handle_memory_usage()/K); | |
381 tty->print_cr(", %d entries (%d KB) <JNI weak globals: %d KB>]", | |
382 entry_count(), hashmap_usage, weak_globals_usage); | |
383 } | |
384 | |
385 // compute threshold for the next trace message | |
386 void JvmtiTagHashmap::compute_next_trace_threshold() { | |
387 if (trace_threshold() < medium_trace_threshold) { | |
388 _trace_threshold += small_trace_threshold; | |
389 } else { | |
390 if (trace_threshold() < large_trace_threshold) { | |
391 _trace_threshold += medium_trace_threshold; | |
392 } else { | |
393 _trace_threshold += large_trace_threshold; | |
394 } | |
395 } | |
396 } | |
397 | |
398 // memory region for young generation | |
399 MemRegion JvmtiTagMap::_young_gen; | |
400 | |
401 // get the memory region used for the young generation | |
402 void JvmtiTagMap::get_young_generation() { | |
342
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403 CollectedHeap* ch = Universe::heap(); |
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404 switch (ch->kind()) { |
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405 case (CollectedHeap::GenCollectedHeap): { |
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406 _young_gen = ((GenCollectedHeap*)ch)->get_gen(0)->reserved(); |
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407 break; |
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408 } |
0 | 409 #ifndef SERIALGC |
342
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410 case (CollectedHeap::ParallelScavengeHeap): { |
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411 _young_gen = ((ParallelScavengeHeap*)ch)->young_gen()->reserved(); |
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412 break; |
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413 } |
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414 case (CollectedHeap::G1CollectedHeap): { |
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415 // Until a more satisfactory solution is implemented, all |
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416 // oops in the tag map will require rehash at each gc. |
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417 // This is a correct, if extremely inefficient solution. |
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418 // See RFE 6621729 for related commentary. |
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419 _young_gen = ch->reserved_region(); |
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420 break; |
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421 } |
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422 #endif // !SERIALGC |
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423 default: |
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424 ShouldNotReachHere(); |
0 | 425 } |
426 } | |
427 | |
428 // returns true if oop is in the young generation | |
429 inline bool JvmtiTagMap::is_in_young(oop o) { | |
430 assert(_young_gen.start() != NULL, "checking"); | |
431 void* p = (void*)o; | |
432 bool in_young = _young_gen.contains(p); | |
433 return in_young; | |
434 } | |
435 | |
436 // returns the appropriate hashmap for a given object | |
437 inline JvmtiTagHashmap* JvmtiTagMap::hashmap_for(oop o) { | |
438 if (is_in_young(o)) { | |
439 return _hashmap[0]; | |
440 } else { | |
441 return _hashmap[1]; | |
442 } | |
443 } | |
444 | |
445 | |
446 // create a JvmtiTagMap | |
447 JvmtiTagMap::JvmtiTagMap(JvmtiEnv* env) : | |
448 _env(env), | |
449 _lock(Mutex::nonleaf+2, "JvmtiTagMap._lock", false), | |
450 _free_entries(NULL), | |
451 _free_entries_count(0) | |
452 { | |
453 assert(JvmtiThreadState_lock->is_locked(), "sanity check"); | |
454 assert(((JvmtiEnvBase *)env)->tag_map() == NULL, "tag map already exists for environment"); | |
455 | |
456 // create the hashmaps | |
457 for (int i=0; i<n_hashmaps; i++) { | |
458 _hashmap[i] = new JvmtiTagHashmap(); | |
459 } | |
460 | |
461 // get the memory region used by the young generation | |
462 get_young_generation(); | |
463 | |
464 // finally add us to the environment | |
465 ((JvmtiEnvBase *)env)->set_tag_map(this); | |
466 } | |
467 | |
468 | |
469 // destroy a JvmtiTagMap | |
470 JvmtiTagMap::~JvmtiTagMap() { | |
471 | |
472 // no lock acquired as we assume the enclosing environment is | |
473 // also being destroryed. | |
474 ((JvmtiEnvBase *)_env)->set_tag_map(NULL); | |
475 | |
476 // iterate over the hashmaps and destroy each of the entries | |
477 for (int i=0; i<n_hashmaps; i++) { | |
478 JvmtiTagHashmap* hashmap = _hashmap[i]; | |
479 JvmtiTagHashmapEntry** table = hashmap->table(); | |
480 for (int j=0; j<hashmap->size(); j++) { | |
481 JvmtiTagHashmapEntry *entry = table[j]; | |
482 while (entry != NULL) { | |
483 JvmtiTagHashmapEntry* next = entry->next(); | |
484 jweak ref = entry->object(); | |
485 JNIHandles::destroy_weak_global(ref); | |
486 delete entry; | |
487 entry = next; | |
488 } | |
489 } | |
490 | |
491 // finally destroy the hashmap | |
492 delete hashmap; | |
493 } | |
494 | |
495 // remove any entries on the free list | |
496 JvmtiTagHashmapEntry* entry = _free_entries; | |
497 while (entry != NULL) { | |
498 JvmtiTagHashmapEntry* next = entry->next(); | |
499 delete entry; | |
500 entry = next; | |
501 } | |
502 } | |
503 | |
504 // create a hashmap entry | |
505 // - if there's an entry on the (per-environment) free list then this | |
506 // is returned. Otherwise an new entry is allocated. | |
507 JvmtiTagHashmapEntry* JvmtiTagMap::create_entry(jweak ref, jlong tag) { | |
508 assert(Thread::current()->is_VM_thread() || is_locked(), "checking"); | |
509 JvmtiTagHashmapEntry* entry; | |
510 if (_free_entries == NULL) { | |
511 entry = new JvmtiTagHashmapEntry(ref, tag); | |
512 } else { | |
513 assert(_free_entries_count > 0, "mismatched _free_entries_count"); | |
514 _free_entries_count--; | |
515 entry = _free_entries; | |
516 _free_entries = entry->next(); | |
517 entry->init(ref, tag); | |
518 } | |
519 return entry; | |
520 } | |
521 | |
522 // destroy an entry by returning it to the free list | |
523 void JvmtiTagMap::destroy_entry(JvmtiTagHashmapEntry* entry) { | |
524 assert(SafepointSynchronize::is_at_safepoint() || is_locked(), "checking"); | |
525 // limit the size of the free list | |
526 if (_free_entries_count >= max_free_entries) { | |
527 delete entry; | |
528 } else { | |
529 entry->set_next(_free_entries); | |
530 _free_entries = entry; | |
531 _free_entries_count++; | |
532 } | |
533 } | |
534 | |
535 // returns the tag map for the given environments. If the tag map | |
536 // doesn't exist then it is created. | |
537 JvmtiTagMap* JvmtiTagMap::tag_map_for(JvmtiEnv* env) { | |
538 JvmtiTagMap* tag_map = ((JvmtiEnvBase *)env)->tag_map(); | |
539 if (tag_map == NULL) { | |
540 MutexLocker mu(JvmtiThreadState_lock); | |
541 tag_map = ((JvmtiEnvBase *)env)->tag_map(); | |
542 if (tag_map == NULL) { | |
543 tag_map = new JvmtiTagMap(env); | |
544 } | |
545 } else { | |
546 CHECK_UNHANDLED_OOPS_ONLY(Thread::current()->clear_unhandled_oops()); | |
547 } | |
548 return tag_map; | |
549 } | |
550 | |
551 // iterate over all entries in the tag map. | |
552 void JvmtiTagMap::entry_iterate(JvmtiTagHashmapEntryClosure* closure) { | |
553 for (int i=0; i<n_hashmaps; i++) { | |
554 JvmtiTagHashmap* hashmap = _hashmap[i]; | |
555 hashmap->entry_iterate(closure); | |
556 } | |
557 } | |
558 | |
559 // returns true if the hashmaps are empty | |
560 bool JvmtiTagMap::is_empty() { | |
561 assert(SafepointSynchronize::is_at_safepoint() || is_locked(), "checking"); | |
562 assert(n_hashmaps == 2, "not implemented"); | |
563 return ((_hashmap[0]->entry_count() == 0) && (_hashmap[1]->entry_count() == 0)); | |
564 } | |
565 | |
566 | |
567 // Return the tag value for an object, or 0 if the object is | |
568 // not tagged | |
569 // | |
570 static inline jlong tag_for(JvmtiTagMap* tag_map, oop o) { | |
571 JvmtiTagHashmapEntry* entry = tag_map->hashmap_for(o)->find(o); | |
572 if (entry == NULL) { | |
573 return 0; | |
574 } else { | |
575 return entry->tag(); | |
576 } | |
577 } | |
578 | |
579 // If the object is a java.lang.Class then return the klassOop, | |
580 // otherwise return the original object | |
581 static inline oop klassOop_if_java_lang_Class(oop o) { | |
582 if (o->klass() == SystemDictionary::class_klass()) { | |
583 if (!java_lang_Class::is_primitive(o)) { | |
584 o = (oop)java_lang_Class::as_klassOop(o); | |
585 assert(o != NULL, "class for non-primitive mirror must exist"); | |
586 } | |
587 } | |
588 return o; | |
589 } | |
590 | |
591 // A CallbackWrapper is a support class for querying and tagging an object | |
592 // around a callback to a profiler. The constructor does pre-callback | |
593 // work to get the tag value, klass tag value, ... and the destructor | |
594 // does the post-callback work of tagging or untagging the object. | |
595 // | |
596 // { | |
597 // CallbackWrapper wrapper(tag_map, o); | |
598 // | |
599 // (*callback)(wrapper.klass_tag(), wrapper.obj_size(), wrapper.obj_tag_p(), ...) | |
600 // | |
601 // } // wrapper goes out of scope here which results in the destructor | |
602 // checking to see if the object has been tagged, untagged, or the | |
603 // tag value has changed. | |
604 // | |
605 class CallbackWrapper : public StackObj { | |
606 private: | |
607 JvmtiTagMap* _tag_map; | |
608 JvmtiTagHashmap* _hashmap; | |
609 JvmtiTagHashmapEntry* _entry; | |
610 oop _o; | |
611 jlong _obj_size; | |
612 jlong _obj_tag; | |
613 klassOop _klass; // the object's class | |
614 jlong _klass_tag; | |
615 | |
616 protected: | |
617 JvmtiTagMap* tag_map() const { return _tag_map; } | |
618 | |
619 // invoked post-callback to tag, untag, or update the tag of an object | |
620 void inline post_callback_tag_update(oop o, JvmtiTagHashmap* hashmap, | |
621 JvmtiTagHashmapEntry* entry, jlong obj_tag); | |
622 public: | |
623 CallbackWrapper(JvmtiTagMap* tag_map, oop o) { | |
624 assert(Thread::current()->is_VM_thread() || tag_map->is_locked(), | |
625 "MT unsafe or must be VM thread"); | |
626 | |
627 // for Classes the klassOop is tagged | |
628 _o = klassOop_if_java_lang_Class(o); | |
629 | |
630 // object size | |
631 _obj_size = _o->size() * wordSize; | |
632 | |
633 // record the context | |
634 _tag_map = tag_map; | |
635 _hashmap = tag_map->hashmap_for(_o); | |
636 _entry = _hashmap->find(_o); | |
637 | |
638 // get object tag | |
639 _obj_tag = (_entry == NULL) ? 0 : _entry->tag(); | |
640 | |
641 // get the class and the class's tag value | |
642 if (_o == o) { | |
643 _klass = _o->klass(); | |
644 } else { | |
645 // if the object represents a runtime class then use the | |
646 // tag for java.lang.Class | |
647 _klass = SystemDictionary::class_klass(); | |
648 } | |
649 _klass_tag = tag_for(tag_map, _klass); | |
650 } | |
651 | |
652 ~CallbackWrapper() { | |
653 post_callback_tag_update(_o, _hashmap, _entry, _obj_tag); | |
654 } | |
655 | |
656 inline jlong* obj_tag_p() { return &_obj_tag; } | |
657 inline jlong obj_size() const { return _obj_size; } | |
658 inline jlong obj_tag() const { return _obj_tag; } | |
659 inline klassOop klass() const { return _klass; } | |
660 inline jlong klass_tag() const { return _klass_tag; } | |
661 }; | |
662 | |
663 | |
664 | |
665 // callback post-callback to tag, untag, or update the tag of an object | |
666 void inline CallbackWrapper::post_callback_tag_update(oop o, | |
667 JvmtiTagHashmap* hashmap, | |
668 JvmtiTagHashmapEntry* entry, | |
669 jlong obj_tag) { | |
670 if (entry == NULL) { | |
671 if (obj_tag != 0) { | |
672 // callback has tagged the object | |
673 assert(Thread::current()->is_VM_thread(), "must be VMThread"); | |
674 HandleMark hm; | |
675 Handle h(o); | |
676 jweak ref = JNIHandles::make_weak_global(h); | |
677 entry = tag_map()->create_entry(ref, obj_tag); | |
678 hashmap->add(o, entry); | |
679 } | |
680 } else { | |
681 // object was previously tagged - the callback may have untagged | |
682 // the object or changed the tag value | |
683 if (obj_tag == 0) { | |
684 jweak ref = entry->object(); | |
685 | |
686 JvmtiTagHashmapEntry* entry_removed = hashmap->remove(o); | |
687 assert(entry_removed == entry, "checking"); | |
688 tag_map()->destroy_entry(entry); | |
689 | |
690 JNIHandles::destroy_weak_global(ref); | |
691 } else { | |
692 if (obj_tag != entry->tag()) { | |
693 entry->set_tag(obj_tag); | |
694 } | |
695 } | |
696 } | |
697 } | |
698 | |
699 // An extended CallbackWrapper used when reporting an object reference | |
700 // to the agent. | |
701 // | |
702 // { | |
703 // TwoOopCallbackWrapper wrapper(tag_map, referrer, o); | |
704 // | |
705 // (*callback)(wrapper.klass_tag(), | |
706 // wrapper.obj_size(), | |
707 // wrapper.obj_tag_p() | |
708 // wrapper.referrer_tag_p(), ...) | |
709 // | |
710 // } // wrapper goes out of scope here which results in the destructor | |
711 // checking to see if the referrer object has been tagged, untagged, | |
712 // or the tag value has changed. | |
713 // | |
714 class TwoOopCallbackWrapper : public CallbackWrapper { | |
715 private: | |
716 bool _is_reference_to_self; | |
717 JvmtiTagHashmap* _referrer_hashmap; | |
718 JvmtiTagHashmapEntry* _referrer_entry; | |
719 oop _referrer; | |
720 jlong _referrer_obj_tag; | |
721 jlong _referrer_klass_tag; | |
722 jlong* _referrer_tag_p; | |
723 | |
724 bool is_reference_to_self() const { return _is_reference_to_self; } | |
725 | |
726 public: | |
727 TwoOopCallbackWrapper(JvmtiTagMap* tag_map, oop referrer, oop o) : | |
728 CallbackWrapper(tag_map, o) | |
729 { | |
730 // self reference needs to be handled in a special way | |
731 _is_reference_to_self = (referrer == o); | |
732 | |
733 if (_is_reference_to_self) { | |
734 _referrer_klass_tag = klass_tag(); | |
735 _referrer_tag_p = obj_tag_p(); | |
736 } else { | |
737 // for Classes the klassOop is tagged | |
738 _referrer = klassOop_if_java_lang_Class(referrer); | |
739 // record the context | |
740 _referrer_hashmap = tag_map->hashmap_for(_referrer); | |
741 _referrer_entry = _referrer_hashmap->find(_referrer); | |
742 | |
743 // get object tag | |
744 _referrer_obj_tag = (_referrer_entry == NULL) ? 0 : _referrer_entry->tag(); | |
745 _referrer_tag_p = &_referrer_obj_tag; | |
746 | |
747 // get referrer class tag. | |
748 klassOop k = (_referrer == referrer) ? // Check if referrer is a class... | |
749 _referrer->klass() // No, just get its class | |
750 : SystemDictionary::class_klass(); // Yes, its class is Class | |
751 _referrer_klass_tag = tag_for(tag_map, k); | |
752 } | |
753 } | |
754 | |
755 ~TwoOopCallbackWrapper() { | |
756 if (!is_reference_to_self()){ | |
757 post_callback_tag_update(_referrer, | |
758 _referrer_hashmap, | |
759 _referrer_entry, | |
760 _referrer_obj_tag); | |
761 } | |
762 } | |
763 | |
764 // address of referrer tag | |
765 // (for a self reference this will return the same thing as obj_tag_p()) | |
766 inline jlong* referrer_tag_p() { return _referrer_tag_p; } | |
767 | |
768 // referrer's class tag | |
769 inline jlong referrer_klass_tag() { return _referrer_klass_tag; } | |
770 }; | |
771 | |
772 // tag an object | |
773 // | |
774 // This function is performance critical. If many threads attempt to tag objects | |
775 // around the same time then it's possible that the Mutex associated with the | |
776 // tag map will be a hot lock. Eliminating this lock will not eliminate the issue | |
777 // because creating a JNI weak reference requires acquiring a global lock also. | |
778 void JvmtiTagMap::set_tag(jobject object, jlong tag) { | |
779 MutexLocker ml(lock()); | |
780 | |
781 // resolve the object | |
782 oop o = JNIHandles::resolve_non_null(object); | |
783 | |
784 // for Classes we tag the klassOop | |
785 o = klassOop_if_java_lang_Class(o); | |
786 | |
787 // see if the object is already tagged | |
788 JvmtiTagHashmap* hashmap = hashmap_for(o); | |
789 JvmtiTagHashmapEntry* entry = hashmap->find(o); | |
790 | |
791 // if the object is not already tagged then we tag it | |
792 if (entry == NULL) { | |
793 if (tag != 0) { | |
794 HandleMark hm; | |
795 Handle h(o); | |
796 jweak ref = JNIHandles::make_weak_global(h); | |
797 | |
798 // the object may have moved because make_weak_global may | |
799 // have blocked - thus it is necessary resolve the handle | |
800 // and re-hash the object. | |
801 o = h(); | |
802 entry = create_entry(ref, tag); | |
803 hashmap_for(o)->add(o, entry); | |
804 } else { | |
805 // no-op | |
806 } | |
807 } else { | |
808 // if the object is already tagged then we either update | |
809 // the tag (if a new tag value has been provided) | |
810 // or remove the object if the new tag value is 0. | |
811 // Removing the object requires that we also delete the JNI | |
812 // weak ref to the object. | |
813 if (tag == 0) { | |
814 jweak ref = entry->object(); | |
815 hashmap->remove(o); | |
816 destroy_entry(entry); | |
817 JNIHandles::destroy_weak_global(ref); | |
818 } else { | |
819 entry->set_tag(tag); | |
820 } | |
821 } | |
822 } | |
823 | |
824 // get the tag for an object | |
825 jlong JvmtiTagMap::get_tag(jobject object) { | |
826 MutexLocker ml(lock()); | |
827 | |
828 // resolve the object | |
829 oop o = JNIHandles::resolve_non_null(object); | |
830 | |
831 // for Classes get the tag from the klassOop | |
832 return tag_for(this, klassOop_if_java_lang_Class(o)); | |
833 } | |
834 | |
835 | |
836 // Helper class used to describe the static or instance fields of a class. | |
837 // For each field it holds the field index (as defined by the JVMTI specification), | |
838 // the field type, and the offset. | |
839 | |
840 class ClassFieldDescriptor: public CHeapObj { | |
841 private: | |
842 int _field_index; | |
843 int _field_offset; | |
844 char _field_type; | |
845 public: | |
846 ClassFieldDescriptor(int index, char type, int offset) : | |
847 _field_index(index), _field_type(type), _field_offset(offset) { | |
848 } | |
849 int field_index() const { return _field_index; } | |
850 char field_type() const { return _field_type; } | |
851 int field_offset() const { return _field_offset; } | |
852 }; | |
853 | |
854 class ClassFieldMap: public CHeapObj { | |
855 private: | |
856 enum { | |
857 initial_field_count = 5 | |
858 }; | |
859 | |
860 // list of field descriptors | |
861 GrowableArray<ClassFieldDescriptor*>* _fields; | |
862 | |
863 // constructor | |
864 ClassFieldMap(); | |
865 | |
866 // add a field | |
867 void add(int index, char type, int offset); | |
868 | |
869 // returns the field count for the given class | |
870 static int compute_field_count(instanceKlassHandle ikh); | |
871 | |
872 public: | |
873 ~ClassFieldMap(); | |
874 | |
875 // access | |
876 int field_count() { return _fields->length(); } | |
877 ClassFieldDescriptor* field_at(int i) { return _fields->at(i); } | |
878 | |
879 // functions to create maps of static or instance fields | |
880 static ClassFieldMap* create_map_of_static_fields(klassOop k); | |
881 static ClassFieldMap* create_map_of_instance_fields(oop obj); | |
882 }; | |
883 | |
884 ClassFieldMap::ClassFieldMap() { | |
885 _fields = new (ResourceObj::C_HEAP) GrowableArray<ClassFieldDescriptor*>(initial_field_count, true); | |
886 } | |
887 | |
888 ClassFieldMap::~ClassFieldMap() { | |
889 for (int i=0; i<_fields->length(); i++) { | |
890 delete _fields->at(i); | |
891 } | |
892 delete _fields; | |
893 } | |
894 | |
895 void ClassFieldMap::add(int index, char type, int offset) { | |
896 ClassFieldDescriptor* field = new ClassFieldDescriptor(index, type, offset); | |
897 _fields->append(field); | |
898 } | |
899 | |
900 // Returns a heap allocated ClassFieldMap to describe the static fields | |
901 // of the given class. | |
902 // | |
903 ClassFieldMap* ClassFieldMap::create_map_of_static_fields(klassOop k) { | |
904 HandleMark hm; | |
905 instanceKlassHandle ikh = instanceKlassHandle(Thread::current(), k); | |
906 | |
907 // create the field map | |
908 ClassFieldMap* field_map = new ClassFieldMap(); | |
909 | |
910 FilteredFieldStream f(ikh, false, false); | |
911 int max_field_index = f.field_count()-1; | |
912 | |
913 int index = 0; | |
914 for (FilteredFieldStream fld(ikh, true, true); !fld.eos(); fld.next(), index++) { | |
915 // ignore instance fields | |
916 if (!fld.access_flags().is_static()) { | |
917 continue; | |
918 } | |
919 field_map->add(max_field_index - index, fld.signature()->byte_at(0), fld.offset()); | |
920 } | |
921 return field_map; | |
922 } | |
923 | |
924 // Returns a heap allocated ClassFieldMap to describe the instance fields | |
925 // of the given class. All instance fields are included (this means public | |
926 // and private fields declared in superclasses and superinterfaces too). | |
927 // | |
928 ClassFieldMap* ClassFieldMap::create_map_of_instance_fields(oop obj) { | |
929 HandleMark hm; | |
930 instanceKlassHandle ikh = instanceKlassHandle(Thread::current(), obj->klass()); | |
931 | |
932 // create the field map | |
933 ClassFieldMap* field_map = new ClassFieldMap(); | |
934 | |
935 FilteredFieldStream f(ikh, false, false); | |
936 | |
937 int max_field_index = f.field_count()-1; | |
938 | |
939 int index = 0; | |
940 for (FilteredFieldStream fld(ikh, false, false); !fld.eos(); fld.next(), index++) { | |
941 // ignore static fields | |
942 if (fld.access_flags().is_static()) { | |
943 continue; | |
944 } | |
945 field_map->add(max_field_index - index, fld.signature()->byte_at(0), fld.offset()); | |
946 } | |
947 | |
948 return field_map; | |
949 } | |
950 | |
951 // Helper class used to cache a ClassFileMap for the instance fields of | |
952 // a cache. A JvmtiCachedClassFieldMap can be cached by an instanceKlass during | |
953 // heap iteration and avoid creating a field map for each object in the heap | |
954 // (only need to create the map when the first instance of a class is encountered). | |
955 // | |
956 class JvmtiCachedClassFieldMap : public CHeapObj { | |
957 private: | |
958 enum { | |
959 initial_class_count = 200 | |
960 }; | |
961 ClassFieldMap* _field_map; | |
962 | |
963 ClassFieldMap* field_map() const { return _field_map; } | |
964 | |
965 JvmtiCachedClassFieldMap(ClassFieldMap* field_map); | |
966 ~JvmtiCachedClassFieldMap(); | |
967 | |
968 static GrowableArray<instanceKlass*>* _class_list; | |
969 static void add_to_class_list(instanceKlass* ik); | |
970 | |
971 public: | |
972 // returns the field map for a given object (returning map cached | |
973 // by instanceKlass if possible | |
974 static ClassFieldMap* get_map_of_instance_fields(oop obj); | |
975 | |
976 // removes the field map from all instanceKlasses - should be | |
977 // called before VM operation completes | |
978 static void clear_cache(); | |
979 | |
980 // returns the number of ClassFieldMap cached by instanceKlasses | |
981 static int cached_field_map_count(); | |
982 }; | |
983 | |
984 GrowableArray<instanceKlass*>* JvmtiCachedClassFieldMap::_class_list; | |
985 | |
986 JvmtiCachedClassFieldMap::JvmtiCachedClassFieldMap(ClassFieldMap* field_map) { | |
987 _field_map = field_map; | |
988 } | |
989 | |
990 JvmtiCachedClassFieldMap::~JvmtiCachedClassFieldMap() { | |
991 if (_field_map != NULL) { | |
992 delete _field_map; | |
993 } | |
994 } | |
995 | |
996 // Marker class to ensure that the class file map cache is only used in a defined | |
997 // scope. | |
998 class ClassFieldMapCacheMark : public StackObj { | |
999 private: | |
1000 static bool _is_active; | |
1001 public: | |
1002 ClassFieldMapCacheMark() { | |
1003 assert(Thread::current()->is_VM_thread(), "must be VMThread"); | |
1004 assert(JvmtiCachedClassFieldMap::cached_field_map_count() == 0, "cache not empty"); | |
1005 assert(!_is_active, "ClassFieldMapCacheMark cannot be nested"); | |
1006 _is_active = true; | |
1007 } | |
1008 ~ClassFieldMapCacheMark() { | |
1009 JvmtiCachedClassFieldMap::clear_cache(); | |
1010 _is_active = false; | |
1011 } | |
1012 static bool is_active() { return _is_active; } | |
1013 }; | |
1014 | |
1015 bool ClassFieldMapCacheMark::_is_active; | |
1016 | |
1017 | |
1018 // record that the given instanceKlass is caching a field map | |
1019 void JvmtiCachedClassFieldMap::add_to_class_list(instanceKlass* ik) { | |
1020 if (_class_list == NULL) { | |
1021 _class_list = new (ResourceObj::C_HEAP) GrowableArray<instanceKlass*>(initial_class_count, true); | |
1022 } | |
1023 _class_list->push(ik); | |
1024 } | |
1025 | |
1026 // returns the instance field map for the given object | |
1027 // (returns field map cached by the instanceKlass if possible) | |
1028 ClassFieldMap* JvmtiCachedClassFieldMap::get_map_of_instance_fields(oop obj) { | |
1029 assert(Thread::current()->is_VM_thread(), "must be VMThread"); | |
1030 assert(ClassFieldMapCacheMark::is_active(), "ClassFieldMapCacheMark not active"); | |
1031 | |
1032 klassOop k = obj->klass(); | |
1033 instanceKlass* ik = instanceKlass::cast(k); | |
1034 | |
1035 // return cached map if possible | |
1036 JvmtiCachedClassFieldMap* cached_map = ik->jvmti_cached_class_field_map(); | |
1037 if (cached_map != NULL) { | |
1038 assert(cached_map->field_map() != NULL, "missing field list"); | |
1039 return cached_map->field_map(); | |
1040 } else { | |
1041 ClassFieldMap* field_map = ClassFieldMap::create_map_of_instance_fields(obj); | |
1042 cached_map = new JvmtiCachedClassFieldMap(field_map); | |
1043 ik->set_jvmti_cached_class_field_map(cached_map); | |
1044 add_to_class_list(ik); | |
1045 return field_map; | |
1046 } | |
1047 } | |
1048 | |
1049 // remove the fields maps cached from all instanceKlasses | |
1050 void JvmtiCachedClassFieldMap::clear_cache() { | |
1051 assert(Thread::current()->is_VM_thread(), "must be VMThread"); | |
1052 if (_class_list != NULL) { | |
1053 for (int i = 0; i < _class_list->length(); i++) { | |
1054 instanceKlass* ik = _class_list->at(i); | |
1055 JvmtiCachedClassFieldMap* cached_map = ik->jvmti_cached_class_field_map(); | |
1056 assert(cached_map != NULL, "should not be NULL"); | |
1057 ik->set_jvmti_cached_class_field_map(NULL); | |
1058 delete cached_map; // deletes the encapsulated field map | |
1059 } | |
1060 delete _class_list; | |
1061 _class_list = NULL; | |
1062 } | |
1063 } | |
1064 | |
1065 // returns the number of ClassFieldMap cached by instanceKlasses | |
1066 int JvmtiCachedClassFieldMap::cached_field_map_count() { | |
1067 return (_class_list == NULL) ? 0 : _class_list->length(); | |
1068 } | |
1069 | |
1070 // helper function to indicate if an object is filtered by its tag or class tag | |
1071 static inline bool is_filtered_by_heap_filter(jlong obj_tag, | |
1072 jlong klass_tag, | |
1073 int heap_filter) { | |
1074 // apply the heap filter | |
1075 if (obj_tag != 0) { | |
1076 // filter out tagged objects | |
1077 if (heap_filter & JVMTI_HEAP_FILTER_TAGGED) return true; | |
1078 } else { | |
1079 // filter out untagged objects | |
1080 if (heap_filter & JVMTI_HEAP_FILTER_UNTAGGED) return true; | |
1081 } | |
1082 if (klass_tag != 0) { | |
1083 // filter out objects with tagged classes | |
1084 if (heap_filter & JVMTI_HEAP_FILTER_CLASS_TAGGED) return true; | |
1085 } else { | |
1086 // filter out objects with untagged classes. | |
1087 if (heap_filter & JVMTI_HEAP_FILTER_CLASS_UNTAGGED) return true; | |
1088 } | |
1089 return false; | |
1090 } | |
1091 | |
1092 // helper function to indicate if an object is filtered by a klass filter | |
1093 static inline bool is_filtered_by_klass_filter(oop obj, KlassHandle klass_filter) { | |
1094 if (!klass_filter.is_null()) { | |
1095 if (obj->klass() != klass_filter()) { | |
1096 return true; | |
1097 } | |
1098 } | |
1099 return false; | |
1100 } | |
1101 | |
1102 // helper function to tell if a field is a primitive field or not | |
1103 static inline bool is_primitive_field_type(char type) { | |
1104 return (type != 'L' && type != '['); | |
1105 } | |
1106 | |
1107 // helper function to copy the value from location addr to jvalue. | |
1108 static inline void copy_to_jvalue(jvalue *v, address addr, jvmtiPrimitiveType value_type) { | |
1109 switch (value_type) { | |
1110 case JVMTI_PRIMITIVE_TYPE_BOOLEAN : { v->z = *(jboolean*)addr; break; } | |
1111 case JVMTI_PRIMITIVE_TYPE_BYTE : { v->b = *(jbyte*)addr; break; } | |
1112 case JVMTI_PRIMITIVE_TYPE_CHAR : { v->c = *(jchar*)addr; break; } | |
1113 case JVMTI_PRIMITIVE_TYPE_SHORT : { v->s = *(jshort*)addr; break; } | |
1114 case JVMTI_PRIMITIVE_TYPE_INT : { v->i = *(jint*)addr; break; } | |
1115 case JVMTI_PRIMITIVE_TYPE_LONG : { v->j = *(jlong*)addr; break; } | |
1116 case JVMTI_PRIMITIVE_TYPE_FLOAT : { v->f = *(jfloat*)addr; break; } | |
1117 case JVMTI_PRIMITIVE_TYPE_DOUBLE : { v->d = *(jdouble*)addr; break; } | |
1118 default: ShouldNotReachHere(); | |
1119 } | |
1120 } | |
1121 | |
1122 // helper function to invoke string primitive value callback | |
1123 // returns visit control flags | |
1124 static jint invoke_string_value_callback(jvmtiStringPrimitiveValueCallback cb, | |
1125 CallbackWrapper* wrapper, | |
1126 oop str, | |
1127 void* user_data) | |
1128 { | |
1129 assert(str->klass() == SystemDictionary::string_klass(), "not a string"); | |
1130 | |
1131 // get the string value and length | |
1132 // (string value may be offset from the base) | |
1133 int s_len = java_lang_String::length(str); | |
1134 typeArrayOop s_value = java_lang_String::value(str); | |
1135 int s_offset = java_lang_String::offset(str); | |
1136 jchar* value; | |
1137 if (s_len > 0) { | |
1138 value = s_value->char_at_addr(s_offset); | |
1139 } else { | |
1140 value = (jchar*) s_value->base(T_CHAR); | |
1141 } | |
1142 | |
1143 // invoke the callback | |
1144 return (*cb)(wrapper->klass_tag(), | |
1145 wrapper->obj_size(), | |
1146 wrapper->obj_tag_p(), | |
1147 value, | |
1148 (jint)s_len, | |
1149 user_data); | |
1150 } | |
1151 | |
1152 // helper function to invoke string primitive value callback | |
1153 // returns visit control flags | |
1154 static jint invoke_array_primitive_value_callback(jvmtiArrayPrimitiveValueCallback cb, | |
1155 CallbackWrapper* wrapper, | |
1156 oop obj, | |
1157 void* user_data) | |
1158 { | |
1159 assert(obj->is_typeArray(), "not a primitive array"); | |
1160 | |
1161 // get base address of first element | |
1162 typeArrayOop array = typeArrayOop(obj); | |
1163 BasicType type = typeArrayKlass::cast(array->klass())->element_type(); | |
1164 void* elements = array->base(type); | |
1165 | |
1166 // jvmtiPrimitiveType is defined so this mapping is always correct | |
1167 jvmtiPrimitiveType elem_type = (jvmtiPrimitiveType)type2char(type); | |
1168 | |
1169 return (*cb)(wrapper->klass_tag(), | |
1170 wrapper->obj_size(), | |
1171 wrapper->obj_tag_p(), | |
1172 (jint)array->length(), | |
1173 elem_type, | |
1174 elements, | |
1175 user_data); | |
1176 } | |
1177 | |
1178 // helper function to invoke the primitive field callback for all static fields | |
1179 // of a given class | |
1180 static jint invoke_primitive_field_callback_for_static_fields | |
1181 (CallbackWrapper* wrapper, | |
1182 oop obj, | |
1183 jvmtiPrimitiveFieldCallback cb, | |
1184 void* user_data) | |
1185 { | |
1186 // for static fields only the index will be set | |
1187 static jvmtiHeapReferenceInfo reference_info = { 0 }; | |
1188 | |
1189 assert(obj->klass() == SystemDictionary::class_klass(), "not a class"); | |
1190 if (java_lang_Class::is_primitive(obj)) { | |
1191 return 0; | |
1192 } | |
1193 klassOop k = java_lang_Class::as_klassOop(obj); | |
1194 Klass* klass = k->klass_part(); | |
1195 | |
1196 // ignore classes for object and type arrays | |
1197 if (!klass->oop_is_instance()) { | |
1198 return 0; | |
1199 } | |
1200 | |
1201 // ignore classes which aren't linked yet | |
1202 instanceKlass* ik = instanceKlass::cast(k); | |
1203 if (!ik->is_linked()) { | |
1204 return 0; | |
1205 } | |
1206 | |
1207 // get the field map | |
1208 ClassFieldMap* field_map = ClassFieldMap::create_map_of_static_fields(k); | |
1209 | |
1210 // invoke the callback for each static primitive field | |
1211 for (int i=0; i<field_map->field_count(); i++) { | |
1212 ClassFieldDescriptor* field = field_map->field_at(i); | |
1213 | |
1214 // ignore non-primitive fields | |
1215 char type = field->field_type(); | |
1216 if (!is_primitive_field_type(type)) { | |
1217 continue; | |
1218 } | |
1219 // one-to-one mapping | |
1220 jvmtiPrimitiveType value_type = (jvmtiPrimitiveType)type; | |
1221 | |
1222 // get offset and field value | |
1223 int offset = field->field_offset(); | |
1224 address addr = (address)k + offset; | |
1225 jvalue value; | |
1226 copy_to_jvalue(&value, addr, value_type); | |
1227 | |
1228 // field index | |
1229 reference_info.field.index = field->field_index(); | |
1230 | |
1231 // invoke the callback | |
1232 jint res = (*cb)(JVMTI_HEAP_REFERENCE_STATIC_FIELD, | |
1233 &reference_info, | |
1234 wrapper->klass_tag(), | |
1235 wrapper->obj_tag_p(), | |
1236 value, | |
1237 value_type, | |
1238 user_data); | |
1239 if (res & JVMTI_VISIT_ABORT) { | |
1240 delete field_map; | |
1241 return res; | |
1242 } | |
1243 } | |
1244 | |
1245 delete field_map; | |
1246 return 0; | |
1247 } | |
1248 | |
1249 // helper function to invoke the primitive field callback for all instance fields | |
1250 // of a given object | |
1251 static jint invoke_primitive_field_callback_for_instance_fields( | |
1252 CallbackWrapper* wrapper, | |
1253 oop obj, | |
1254 jvmtiPrimitiveFieldCallback cb, | |
1255 void* user_data) | |
1256 { | |
1257 // for instance fields only the index will be set | |
1258 static jvmtiHeapReferenceInfo reference_info = { 0 }; | |
1259 | |
1260 // get the map of the instance fields | |
1261 ClassFieldMap* fields = JvmtiCachedClassFieldMap::get_map_of_instance_fields(obj); | |
1262 | |
1263 // invoke the callback for each instance primitive field | |
1264 for (int i=0; i<fields->field_count(); i++) { | |
1265 ClassFieldDescriptor* field = fields->field_at(i); | |
1266 | |
1267 // ignore non-primitive fields | |
1268 char type = field->field_type(); | |
1269 if (!is_primitive_field_type(type)) { | |
1270 continue; | |
1271 } | |
1272 // one-to-one mapping | |
1273 jvmtiPrimitiveType value_type = (jvmtiPrimitiveType)type; | |
1274 | |
1275 // get offset and field value | |
1276 int offset = field->field_offset(); | |
1277 address addr = (address)obj + offset; | |
1278 jvalue value; | |
1279 copy_to_jvalue(&value, addr, value_type); | |
1280 | |
1281 // field index | |
1282 reference_info.field.index = field->field_index(); | |
1283 | |
1284 // invoke the callback | |
1285 jint res = (*cb)(JVMTI_HEAP_REFERENCE_FIELD, | |
1286 &reference_info, | |
1287 wrapper->klass_tag(), | |
1288 wrapper->obj_tag_p(), | |
1289 value, | |
1290 value_type, | |
1291 user_data); | |
1292 if (res & JVMTI_VISIT_ABORT) { | |
1293 return res; | |
1294 } | |
1295 } | |
1296 return 0; | |
1297 } | |
1298 | |
1299 | |
1300 // VM operation to iterate over all objects in the heap (both reachable | |
1301 // and unreachable) | |
1302 class VM_HeapIterateOperation: public VM_Operation { | |
1303 private: | |
1304 ObjectClosure* _blk; | |
1305 public: | |
1306 VM_HeapIterateOperation(ObjectClosure* blk) { _blk = blk; } | |
1307 | |
1308 VMOp_Type type() const { return VMOp_HeapIterateOperation; } | |
1309 void doit() { | |
1310 // allows class files maps to be cached during iteration | |
1311 ClassFieldMapCacheMark cm; | |
1312 | |
1313 // make sure that heap is parsable (fills TLABs with filler objects) | |
1314 Universe::heap()->ensure_parsability(false); // no need to retire TLABs | |
1315 | |
1316 // Verify heap before iteration - if the heap gets corrupted then | |
1317 // JVMTI's IterateOverHeap will crash. | |
1318 if (VerifyBeforeIteration) { | |
1319 Universe::verify(); | |
1320 } | |
1321 | |
1322 // do the iteration | |
517
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1323 // If this operation encounters a bad object when using CMS, |
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1324 // consider using safe_object_iterate() which avoids perm gen |
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1325 // objects that may contain bad references. |
0 | 1326 Universe::heap()->object_iterate(_blk); |
1327 | |
1328 // when sharing is enabled we must iterate over the shared spaces | |
1329 if (UseSharedSpaces) { | |
1330 GenCollectedHeap* gch = GenCollectedHeap::heap(); | |
1331 CompactingPermGenGen* gen = (CompactingPermGenGen*)gch->perm_gen(); | |
1332 gen->ro_space()->object_iterate(_blk); | |
1333 gen->rw_space()->object_iterate(_blk); | |
1334 } | |
1335 } | |
1336 | |
1337 }; | |
1338 | |
1339 | |
1340 // An ObjectClosure used to support the deprecated IterateOverHeap and | |
1341 // IterateOverInstancesOfClass functions | |
1342 class IterateOverHeapObjectClosure: public ObjectClosure { | |
1343 private: | |
1344 JvmtiTagMap* _tag_map; | |
1345 KlassHandle _klass; | |
1346 jvmtiHeapObjectFilter _object_filter; | |
1347 jvmtiHeapObjectCallback _heap_object_callback; | |
1348 const void* _user_data; | |
1349 | |
1350 // accessors | |
1351 JvmtiTagMap* tag_map() const { return _tag_map; } | |
1352 jvmtiHeapObjectFilter object_filter() const { return _object_filter; } | |
1353 jvmtiHeapObjectCallback object_callback() const { return _heap_object_callback; } | |
1354 KlassHandle klass() const { return _klass; } | |
1355 const void* user_data() const { return _user_data; } | |
1356 | |
1357 // indicates if iteration has been aborted | |
1358 bool _iteration_aborted; | |
1359 bool is_iteration_aborted() const { return _iteration_aborted; } | |
1360 void set_iteration_aborted(bool aborted) { _iteration_aborted = aborted; } | |
1361 | |
1362 public: | |
1363 IterateOverHeapObjectClosure(JvmtiTagMap* tag_map, | |
1364 KlassHandle klass, | |
1365 jvmtiHeapObjectFilter object_filter, | |
1366 jvmtiHeapObjectCallback heap_object_callback, | |
1367 const void* user_data) : | |
1368 _tag_map(tag_map), | |
1369 _klass(klass), | |
1370 _object_filter(object_filter), | |
1371 _heap_object_callback(heap_object_callback), | |
1372 _user_data(user_data), | |
1373 _iteration_aborted(false) | |
1374 { | |
1375 } | |
1376 | |
1377 void do_object(oop o); | |
1378 }; | |
1379 | |
1380 // invoked for each object in the heap | |
1381 void IterateOverHeapObjectClosure::do_object(oop o) { | |
1382 // check if iteration has been halted | |
1383 if (is_iteration_aborted()) return; | |
1384 | |
1385 // ignore any objects that aren't visible to profiler | |
1386 if (!ServiceUtil::visible_oop(o)) return; | |
1387 | |
1388 // instanceof check when filtering by klass | |
1389 if (!klass().is_null() && !o->is_a(klass()())) { | |
1390 return; | |
1391 } | |
1392 // prepare for the calllback | |
1393 CallbackWrapper wrapper(tag_map(), o); | |
1394 | |
1395 // if the object is tagged and we're only interested in untagged objects | |
1396 // then don't invoke the callback. Similiarly, if the object is untagged | |
1397 // and we're only interested in tagged objects we skip the callback. | |
1398 if (wrapper.obj_tag() != 0) { | |
1399 if (object_filter() == JVMTI_HEAP_OBJECT_UNTAGGED) return; | |
1400 } else { | |
1401 if (object_filter() == JVMTI_HEAP_OBJECT_TAGGED) return; | |
1402 } | |
1403 | |
1404 // invoke the agent's callback | |
1405 jvmtiIterationControl control = (*object_callback())(wrapper.klass_tag(), | |
1406 wrapper.obj_size(), | |
1407 wrapper.obj_tag_p(), | |
1408 (void*)user_data()); | |
1409 if (control == JVMTI_ITERATION_ABORT) { | |
1410 set_iteration_aborted(true); | |
1411 } | |
1412 } | |
1413 | |
1414 // An ObjectClosure used to support the IterateThroughHeap function | |
1415 class IterateThroughHeapObjectClosure: public ObjectClosure { | |
1416 private: | |
1417 JvmtiTagMap* _tag_map; | |
1418 KlassHandle _klass; | |
1419 int _heap_filter; | |
1420 const jvmtiHeapCallbacks* _callbacks; | |
1421 const void* _user_data; | |
1422 | |
1423 // accessor functions | |
1424 JvmtiTagMap* tag_map() const { return _tag_map; } | |
1425 int heap_filter() const { return _heap_filter; } | |
1426 const jvmtiHeapCallbacks* callbacks() const { return _callbacks; } | |
1427 KlassHandle klass() const { return _klass; } | |
1428 const void* user_data() const { return _user_data; } | |
1429 | |
1430 // indicates if the iteration has been aborted | |
1431 bool _iteration_aborted; | |
1432 bool is_iteration_aborted() const { return _iteration_aborted; } | |
1433 | |
1434 // used to check the visit control flags. If the abort flag is set | |
1435 // then we set the iteration aborted flag so that the iteration completes | |
1436 // without processing any further objects | |
1437 bool check_flags_for_abort(jint flags) { | |
1438 bool is_abort = (flags & JVMTI_VISIT_ABORT) != 0; | |
1439 if (is_abort) { | |
1440 _iteration_aborted = true; | |
1441 } | |
1442 return is_abort; | |
1443 } | |
1444 | |
1445 public: | |
1446 IterateThroughHeapObjectClosure(JvmtiTagMap* tag_map, | |
1447 KlassHandle klass, | |
1448 int heap_filter, | |
1449 const jvmtiHeapCallbacks* heap_callbacks, | |
1450 const void* user_data) : | |
1451 _tag_map(tag_map), | |
1452 _klass(klass), | |
1453 _heap_filter(heap_filter), | |
1454 _callbacks(heap_callbacks), | |
1455 _user_data(user_data), | |
1456 _iteration_aborted(false) | |
1457 { | |
1458 } | |
1459 | |
1460 void do_object(oop o); | |
1461 }; | |
1462 | |
1463 // invoked for each object in the heap | |
1464 void IterateThroughHeapObjectClosure::do_object(oop obj) { | |
1465 // check if iteration has been halted | |
1466 if (is_iteration_aborted()) return; | |
1467 | |
1468 // ignore any objects that aren't visible to profiler | |
1469 if (!ServiceUtil::visible_oop(obj)) return; | |
1470 | |
1471 // apply class filter | |
1472 if (is_filtered_by_klass_filter(obj, klass())) return; | |
1473 | |
1474 // prepare for callback | |
1475 CallbackWrapper wrapper(tag_map(), obj); | |
1476 | |
1477 // check if filtered by the heap filter | |
1478 if (is_filtered_by_heap_filter(wrapper.obj_tag(), wrapper.klass_tag(), heap_filter())) { | |
1479 return; | |
1480 } | |
1481 | |
1482 // for arrays we need the length, otherwise -1 | |
1483 bool is_array = obj->is_array(); | |
1484 int len = is_array ? arrayOop(obj)->length() : -1; | |
1485 | |
1486 // invoke the object callback (if callback is provided) | |
1487 if (callbacks()->heap_iteration_callback != NULL) { | |
1488 jvmtiHeapIterationCallback cb = callbacks()->heap_iteration_callback; | |
1489 jint res = (*cb)(wrapper.klass_tag(), | |
1490 wrapper.obj_size(), | |
1491 wrapper.obj_tag_p(), | |
1492 (jint)len, | |
1493 (void*)user_data()); | |
1494 if (check_flags_for_abort(res)) return; | |
1495 } | |
1496 | |
1497 // for objects and classes we report primitive fields if callback provided | |
1498 if (callbacks()->primitive_field_callback != NULL && obj->is_instance()) { | |
1499 jint res; | |
1500 jvmtiPrimitiveFieldCallback cb = callbacks()->primitive_field_callback; | |
1501 if (obj->klass() == SystemDictionary::class_klass()) { | |
1502 res = invoke_primitive_field_callback_for_static_fields(&wrapper, | |
1503 obj, | |
1504 cb, | |
1505 (void*)user_data()); | |
1506 } else { | |
1507 res = invoke_primitive_field_callback_for_instance_fields(&wrapper, | |
1508 obj, | |
1509 cb, | |
1510 (void*)user_data()); | |
1511 } | |
1512 if (check_flags_for_abort(res)) return; | |
1513 } | |
1514 | |
1515 // string callback | |
1516 if (!is_array && | |
1517 callbacks()->string_primitive_value_callback != NULL && | |
1518 obj->klass() == SystemDictionary::string_klass()) { | |
1519 jint res = invoke_string_value_callback( | |
1520 callbacks()->string_primitive_value_callback, | |
1521 &wrapper, | |
1522 obj, | |
1523 (void*)user_data() ); | |
1524 if (check_flags_for_abort(res)) return; | |
1525 } | |
1526 | |
1527 // array callback | |
1528 if (is_array && | |
1529 callbacks()->array_primitive_value_callback != NULL && | |
1530 obj->is_typeArray()) { | |
1531 jint res = invoke_array_primitive_value_callback( | |
1532 callbacks()->array_primitive_value_callback, | |
1533 &wrapper, | |
1534 obj, | |
1535 (void*)user_data() ); | |
1536 if (check_flags_for_abort(res)) return; | |
1537 } | |
1538 }; | |
1539 | |
1540 | |
1541 // Deprecated function to iterate over all objects in the heap | |
1542 void JvmtiTagMap::iterate_over_heap(jvmtiHeapObjectFilter object_filter, | |
1543 KlassHandle klass, | |
1544 jvmtiHeapObjectCallback heap_object_callback, | |
1545 const void* user_data) | |
1546 { | |
1547 MutexLocker ml(Heap_lock); | |
1548 IterateOverHeapObjectClosure blk(this, | |
1549 klass, | |
1550 object_filter, | |
1551 heap_object_callback, | |
1552 user_data); | |
1553 VM_HeapIterateOperation op(&blk); | |
1554 VMThread::execute(&op); | |
1555 } | |
1556 | |
1557 | |
1558 // Iterates over all objects in the heap | |
1559 void JvmtiTagMap::iterate_through_heap(jint heap_filter, | |
1560 KlassHandle klass, | |
1561 const jvmtiHeapCallbacks* callbacks, | |
1562 const void* user_data) | |
1563 { | |
1564 MutexLocker ml(Heap_lock); | |
1565 IterateThroughHeapObjectClosure blk(this, | |
1566 klass, | |
1567 heap_filter, | |
1568 callbacks, | |
1569 user_data); | |
1570 VM_HeapIterateOperation op(&blk); | |
1571 VMThread::execute(&op); | |
1572 } | |
1573 | |
1574 // support class for get_objects_with_tags | |
1575 | |
1576 class TagObjectCollector : public JvmtiTagHashmapEntryClosure { | |
1577 private: | |
1578 JvmtiEnv* _env; | |
1579 jlong* _tags; | |
1580 jint _tag_count; | |
1581 | |
1582 GrowableArray<jobject>* _object_results; // collected objects (JNI weak refs) | |
1583 GrowableArray<uint64_t>* _tag_results; // collected tags | |
1584 | |
1585 public: | |
1586 TagObjectCollector(JvmtiEnv* env, const jlong* tags, jint tag_count) { | |
1587 _env = env; | |
1588 _tags = (jlong*)tags; | |
1589 _tag_count = tag_count; | |
1590 _object_results = new (ResourceObj::C_HEAP) GrowableArray<jobject>(1,true); | |
1591 _tag_results = new (ResourceObj::C_HEAP) GrowableArray<uint64_t>(1,true); | |
1592 } | |
1593 | |
1594 ~TagObjectCollector() { | |
1595 delete _object_results; | |
1596 delete _tag_results; | |
1597 } | |
1598 | |
1599 // for each tagged object check if the tag value matches | |
1600 // - if it matches then we create a JNI local reference to the object | |
1601 // and record the reference and tag value. | |
1602 // | |
1603 void do_entry(JvmtiTagHashmapEntry* entry) { | |
1604 for (int i=0; i<_tag_count; i++) { | |
1605 if (_tags[i] == entry->tag()) { | |
1606 oop o = JNIHandles::resolve(entry->object()); | |
1607 assert(o != NULL && o != JNIHandles::deleted_handle(), "sanity check"); | |
1608 | |
1609 // the mirror is tagged | |
1610 if (o->is_klass()) { | |
1611 klassOop k = (klassOop)o; | |
1612 o = Klass::cast(k)->java_mirror(); | |
1613 } | |
1614 | |
1615 jobject ref = JNIHandles::make_local(JavaThread::current(), o); | |
1616 _object_results->append(ref); | |
1617 _tag_results->append((uint64_t)entry->tag()); | |
1618 } | |
1619 } | |
1620 } | |
1621 | |
1622 // return the results from the collection | |
1623 // | |
1624 jvmtiError result(jint* count_ptr, jobject** object_result_ptr, jlong** tag_result_ptr) { | |
1625 jvmtiError error; | |
1626 int count = _object_results->length(); | |
1627 assert(count >= 0, "sanity check"); | |
1628 | |
1629 // if object_result_ptr is not NULL then allocate the result and copy | |
1630 // in the object references. | |
1631 if (object_result_ptr != NULL) { | |
1632 error = _env->Allocate(count * sizeof(jobject), (unsigned char**)object_result_ptr); | |
1633 if (error != JVMTI_ERROR_NONE) { | |
1634 return error; | |
1635 } | |
1636 for (int i=0; i<count; i++) { | |
1637 (*object_result_ptr)[i] = _object_results->at(i); | |
1638 } | |
1639 } | |
1640 | |
1641 // if tag_result_ptr is not NULL then allocate the result and copy | |
1642 // in the tag values. | |
1643 if (tag_result_ptr != NULL) { | |
1644 error = _env->Allocate(count * sizeof(jlong), (unsigned char**)tag_result_ptr); | |
1645 if (error != JVMTI_ERROR_NONE) { | |
1646 if (object_result_ptr != NULL) { | |
1647 _env->Deallocate((unsigned char*)object_result_ptr); | |
1648 } | |
1649 return error; | |
1650 } | |
1651 for (int i=0; i<count; i++) { | |
1652 (*tag_result_ptr)[i] = (jlong)_tag_results->at(i); | |
1653 } | |
1654 } | |
1655 | |
1656 *count_ptr = count; | |
1657 return JVMTI_ERROR_NONE; | |
1658 } | |
1659 }; | |
1660 | |
1661 // return the list of objects with the specified tags | |
1662 jvmtiError JvmtiTagMap::get_objects_with_tags(const jlong* tags, | |
1663 jint count, jint* count_ptr, jobject** object_result_ptr, jlong** tag_result_ptr) { | |
1664 | |
1665 TagObjectCollector collector(env(), tags, count); | |
1666 { | |
1667 // iterate over all tagged objects | |
1668 MutexLocker ml(lock()); | |
1669 entry_iterate(&collector); | |
1670 } | |
1671 return collector.result(count_ptr, object_result_ptr, tag_result_ptr); | |
1672 } | |
1673 | |
1674 | |
1675 // ObjectMarker is used to support the marking objects when walking the | |
1676 // heap. | |
1677 // | |
1678 // This implementation uses the existing mark bits in an object for | |
1679 // marking. Objects that are marked must later have their headers restored. | |
1680 // As most objects are unlocked and don't have their identity hash computed | |
1681 // we don't have to save their headers. Instead we save the headers that | |
1682 // are "interesting". Later when the headers are restored this implementation | |
1683 // restores all headers to their initial value and then restores the few | |
1684 // objects that had interesting headers. | |
1685 // | |
1686 // Future work: This implementation currently uses growable arrays to save | |
1687 // the oop and header of interesting objects. As an optimization we could | |
1688 // use the same technique as the GC and make use of the unused area | |
1689 // between top() and end(). | |
1690 // | |
1691 | |
1692 // An ObjectClosure used to restore the mark bits of an object | |
1693 class RestoreMarksClosure : public ObjectClosure { | |
1694 public: | |
1695 void do_object(oop o) { | |
1696 if (o != NULL) { | |
1697 markOop mark = o->mark(); | |
1698 if (mark->is_marked()) { | |
1699 o->init_mark(); | |
1700 } | |
1701 } | |
1702 } | |
1703 }; | |
1704 | |
1705 // ObjectMarker provides the mark and visited functions | |
1706 class ObjectMarker : AllStatic { | |
1707 private: | |
1708 // saved headers | |
1709 static GrowableArray<oop>* _saved_oop_stack; | |
1710 static GrowableArray<markOop>* _saved_mark_stack; | |
1711 | |
1712 public: | |
1713 static void init(); // initialize | |
1714 static void done(); // clean-up | |
1715 | |
1716 static inline void mark(oop o); // mark an object | |
1717 static inline bool visited(oop o); // check if object has been visited | |
1718 }; | |
1719 | |
1720 GrowableArray<oop>* ObjectMarker::_saved_oop_stack = NULL; | |
1721 GrowableArray<markOop>* ObjectMarker::_saved_mark_stack = NULL; | |
1722 | |
1723 // initialize ObjectMarker - prepares for object marking | |
1724 void ObjectMarker::init() { | |
1725 assert(Thread::current()->is_VM_thread(), "must be VMThread"); | |
1726 | |
1727 // prepare heap for iteration | |
1728 Universe::heap()->ensure_parsability(false); // no need to retire TLABs | |
1729 | |
1730 // create stacks for interesting headers | |
1731 _saved_mark_stack = new (ResourceObj::C_HEAP) GrowableArray<markOop>(4000, true); | |
1732 _saved_oop_stack = new (ResourceObj::C_HEAP) GrowableArray<oop>(4000, true); | |
1733 | |
1734 if (UseBiasedLocking) { | |
1735 BiasedLocking::preserve_marks(); | |
1736 } | |
1737 } | |
1738 | |
1739 // Object marking is done so restore object headers | |
1740 void ObjectMarker::done() { | |
1741 // iterate over all objects and restore the mark bits to | |
1742 // their initial value | |
1743 RestoreMarksClosure blk; | |
1744 Universe::heap()->object_iterate(&blk); | |
1745 | |
1746 // When sharing is enabled we need to restore the headers of the objects | |
1747 // in the readwrite space too. | |
1748 if (UseSharedSpaces) { | |
1749 GenCollectedHeap* gch = GenCollectedHeap::heap(); | |
1750 CompactingPermGenGen* gen = (CompactingPermGenGen*)gch->perm_gen(); | |
1751 gen->rw_space()->object_iterate(&blk); | |
1752 } | |
1753 | |
1754 // now restore the interesting headers | |
1755 for (int i = 0; i < _saved_oop_stack->length(); i++) { | |
1756 oop o = _saved_oop_stack->at(i); | |
1757 markOop mark = _saved_mark_stack->at(i); | |
1758 o->set_mark(mark); | |
1759 } | |
1760 | |
1761 if (UseBiasedLocking) { | |
1762 BiasedLocking::restore_marks(); | |
1763 } | |
1764 | |
1765 // free the stacks | |
1766 delete _saved_oop_stack; | |
1767 delete _saved_mark_stack; | |
1768 } | |
1769 | |
1770 // mark an object | |
1771 inline void ObjectMarker::mark(oop o) { | |
1772 assert(Universe::heap()->is_in(o), "sanity check"); | |
1773 assert(!o->mark()->is_marked(), "should only mark an object once"); | |
1774 | |
1775 // object's mark word | |
1776 markOop mark = o->mark(); | |
1777 | |
1778 if (mark->must_be_preserved(o)) { | |
1779 _saved_mark_stack->push(mark); | |
1780 _saved_oop_stack->push(o); | |
1781 } | |
1782 | |
1783 // mark the object | |
1784 o->set_mark(markOopDesc::prototype()->set_marked()); | |
1785 } | |
1786 | |
1787 // return true if object is marked | |
1788 inline bool ObjectMarker::visited(oop o) { | |
1789 return o->mark()->is_marked(); | |
1790 } | |
1791 | |
1792 // Stack allocated class to help ensure that ObjectMarker is used | |
1793 // correctly. Constructor initializes ObjectMarker, destructor calls | |
1794 // ObjectMarker's done() function to restore object headers. | |
1795 class ObjectMarkerController : public StackObj { | |
1796 public: | |
1797 ObjectMarkerController() { | |
1798 ObjectMarker::init(); | |
1799 } | |
1800 ~ObjectMarkerController() { | |
1801 ObjectMarker::done(); | |
1802 } | |
1803 }; | |
1804 | |
1805 | |
1806 // helper to map a jvmtiHeapReferenceKind to an old style jvmtiHeapRootKind | |
1807 // (not performance critical as only used for roots) | |
1808 static jvmtiHeapRootKind toJvmtiHeapRootKind(jvmtiHeapReferenceKind kind) { | |
1809 switch (kind) { | |
1810 case JVMTI_HEAP_REFERENCE_JNI_GLOBAL: return JVMTI_HEAP_ROOT_JNI_GLOBAL; | |
1811 case JVMTI_HEAP_REFERENCE_SYSTEM_CLASS: return JVMTI_HEAP_ROOT_SYSTEM_CLASS; | |
1812 case JVMTI_HEAP_REFERENCE_MONITOR: return JVMTI_HEAP_ROOT_MONITOR; | |
1813 case JVMTI_HEAP_REFERENCE_STACK_LOCAL: return JVMTI_HEAP_ROOT_STACK_LOCAL; | |
1814 case JVMTI_HEAP_REFERENCE_JNI_LOCAL: return JVMTI_HEAP_ROOT_JNI_LOCAL; | |
1815 case JVMTI_HEAP_REFERENCE_THREAD: return JVMTI_HEAP_ROOT_THREAD; | |
1816 case JVMTI_HEAP_REFERENCE_OTHER: return JVMTI_HEAP_ROOT_OTHER; | |
1817 default: ShouldNotReachHere(); return JVMTI_HEAP_ROOT_OTHER; | |
1818 } | |
1819 } | |
1820 | |
1821 // Base class for all heap walk contexts. The base class maintains a flag | |
1822 // to indicate if the context is valid or not. | |
1823 class HeapWalkContext VALUE_OBJ_CLASS_SPEC { | |
1824 private: | |
1825 bool _valid; | |
1826 public: | |
1827 HeapWalkContext(bool valid) { _valid = valid; } | |
1828 void invalidate() { _valid = false; } | |
1829 bool is_valid() const { return _valid; } | |
1830 }; | |
1831 | |
1832 // A basic heap walk context for the deprecated heap walking functions. | |
1833 // The context for a basic heap walk are the callbacks and fields used by | |
1834 // the referrer caching scheme. | |
1835 class BasicHeapWalkContext: public HeapWalkContext { | |
1836 private: | |
1837 jvmtiHeapRootCallback _heap_root_callback; | |
1838 jvmtiStackReferenceCallback _stack_ref_callback; | |
1839 jvmtiObjectReferenceCallback _object_ref_callback; | |
1840 | |
1841 // used for caching | |
1842 oop _last_referrer; | |
1843 jlong _last_referrer_tag; | |
1844 | |
1845 public: | |
1846 BasicHeapWalkContext() : HeapWalkContext(false) { } | |
1847 | |
1848 BasicHeapWalkContext(jvmtiHeapRootCallback heap_root_callback, | |
1849 jvmtiStackReferenceCallback stack_ref_callback, | |
1850 jvmtiObjectReferenceCallback object_ref_callback) : | |
1851 HeapWalkContext(true), | |
1852 _heap_root_callback(heap_root_callback), | |
1853 _stack_ref_callback(stack_ref_callback), | |
1854 _object_ref_callback(object_ref_callback), | |
1855 _last_referrer(NULL), | |
1856 _last_referrer_tag(0) { | |
1857 } | |
1858 | |
1859 // accessors | |
1860 jvmtiHeapRootCallback heap_root_callback() const { return _heap_root_callback; } | |
1861 jvmtiStackReferenceCallback stack_ref_callback() const { return _stack_ref_callback; } | |
1862 jvmtiObjectReferenceCallback object_ref_callback() const { return _object_ref_callback; } | |
1863 | |
1864 oop last_referrer() const { return _last_referrer; } | |
1865 void set_last_referrer(oop referrer) { _last_referrer = referrer; } | |
1866 jlong last_referrer_tag() const { return _last_referrer_tag; } | |
1867 void set_last_referrer_tag(jlong value) { _last_referrer_tag = value; } | |
1868 }; | |
1869 | |
1870 // The advanced heap walk context for the FollowReferences functions. | |
1871 // The context is the callbacks, and the fields used for filtering. | |
1872 class AdvancedHeapWalkContext: public HeapWalkContext { | |
1873 private: | |
1874 jint _heap_filter; | |
1875 KlassHandle _klass_filter; | |
1876 const jvmtiHeapCallbacks* _heap_callbacks; | |
1877 | |
1878 public: | |
1879 AdvancedHeapWalkContext() : HeapWalkContext(false) { } | |
1880 | |
1881 AdvancedHeapWalkContext(jint heap_filter, | |
1882 KlassHandle klass_filter, | |
1883 const jvmtiHeapCallbacks* heap_callbacks) : | |
1884 HeapWalkContext(true), | |
1885 _heap_filter(heap_filter), | |
1886 _klass_filter(klass_filter), | |
1887 _heap_callbacks(heap_callbacks) { | |
1888 } | |
1889 | |
1890 // accessors | |
1891 jint heap_filter() const { return _heap_filter; } | |
1892 KlassHandle klass_filter() const { return _klass_filter; } | |
1893 | |
1894 const jvmtiHeapReferenceCallback heap_reference_callback() const { | |
1895 return _heap_callbacks->heap_reference_callback; | |
1896 }; | |
1897 const jvmtiPrimitiveFieldCallback primitive_field_callback() const { | |
1898 return _heap_callbacks->primitive_field_callback; | |
1899 } | |
1900 const jvmtiArrayPrimitiveValueCallback array_primitive_value_callback() const { | |
1901 return _heap_callbacks->array_primitive_value_callback; | |
1902 } | |
1903 const jvmtiStringPrimitiveValueCallback string_primitive_value_callback() const { | |
1904 return _heap_callbacks->string_primitive_value_callback; | |
1905 } | |
1906 }; | |
1907 | |
1908 // The CallbackInvoker is a class with static functions that the heap walk can call | |
1909 // into to invoke callbacks. It works in one of two modes. The "basic" mode is | |
1910 // used for the deprecated IterateOverReachableObjects functions. The "advanced" | |
1911 // mode is for the newer FollowReferences function which supports a lot of | |
1912 // additional callbacks. | |
1913 class CallbackInvoker : AllStatic { | |
1914 private: | |
1915 // heap walk styles | |
1916 enum { basic, advanced }; | |
1917 static int _heap_walk_type; | |
1918 static bool is_basic_heap_walk() { return _heap_walk_type == basic; } | |
1919 static bool is_advanced_heap_walk() { return _heap_walk_type == advanced; } | |
1920 | |
1921 // context for basic style heap walk | |
1922 static BasicHeapWalkContext _basic_context; | |
1923 static BasicHeapWalkContext* basic_context() { | |
1924 assert(_basic_context.is_valid(), "invalid"); | |
1925 return &_basic_context; | |
1926 } | |
1927 | |
1928 // context for advanced style heap walk | |
1929 static AdvancedHeapWalkContext _advanced_context; | |
1930 static AdvancedHeapWalkContext* advanced_context() { | |
1931 assert(_advanced_context.is_valid(), "invalid"); | |
1932 return &_advanced_context; | |
1933 } | |
1934 | |
1935 // context needed for all heap walks | |
1936 static JvmtiTagMap* _tag_map; | |
1937 static const void* _user_data; | |
1938 static GrowableArray<oop>* _visit_stack; | |
1939 | |
1940 // accessors | |
1941 static JvmtiTagMap* tag_map() { return _tag_map; } | |
1942 static const void* user_data() { return _user_data; } | |
1943 static GrowableArray<oop>* visit_stack() { return _visit_stack; } | |
1944 | |
1945 // if the object hasn't been visited then push it onto the visit stack | |
1946 // so that it will be visited later | |
1947 static inline bool check_for_visit(oop obj) { | |
1948 if (!ObjectMarker::visited(obj)) visit_stack()->push(obj); | |
1949 return true; | |
1950 } | |
1951 | |
1952 // invoke basic style callbacks | |
1953 static inline bool invoke_basic_heap_root_callback | |
1954 (jvmtiHeapRootKind root_kind, oop obj); | |
1955 static inline bool invoke_basic_stack_ref_callback | |
1956 (jvmtiHeapRootKind root_kind, jlong thread_tag, jint depth, jmethodID method, | |
1957 int slot, oop obj); | |
1958 static inline bool invoke_basic_object_reference_callback | |
1959 (jvmtiObjectReferenceKind ref_kind, oop referrer, oop referree, jint index); | |
1960 | |
1961 // invoke advanced style callbacks | |
1962 static inline bool invoke_advanced_heap_root_callback | |
1963 (jvmtiHeapReferenceKind ref_kind, oop obj); | |
1964 static inline bool invoke_advanced_stack_ref_callback | |
1965 (jvmtiHeapReferenceKind ref_kind, jlong thread_tag, jlong tid, int depth, | |
1966 jmethodID method, jlocation bci, jint slot, oop obj); | |
1967 static inline bool invoke_advanced_object_reference_callback | |
1968 (jvmtiHeapReferenceKind ref_kind, oop referrer, oop referree, jint index); | |
1969 | |
1970 // used to report the value of primitive fields | |
1971 static inline bool report_primitive_field | |
1972 (jvmtiHeapReferenceKind ref_kind, oop obj, jint index, address addr, char type); | |
1973 | |
1974 public: | |
1975 // initialize for basic mode | |
1976 static void initialize_for_basic_heap_walk(JvmtiTagMap* tag_map, | |
1977 GrowableArray<oop>* visit_stack, | |
1978 const void* user_data, | |
1979 BasicHeapWalkContext context); | |
1980 | |
1981 // initialize for advanced mode | |
1982 static void initialize_for_advanced_heap_walk(JvmtiTagMap* tag_map, | |
1983 GrowableArray<oop>* visit_stack, | |
1984 const void* user_data, | |
1985 AdvancedHeapWalkContext context); | |
1986 | |
1987 // functions to report roots | |
1988 static inline bool report_simple_root(jvmtiHeapReferenceKind kind, oop o); | |
1989 static inline bool report_jni_local_root(jlong thread_tag, jlong tid, jint depth, | |
1990 jmethodID m, oop o); | |
1991 static inline bool report_stack_ref_root(jlong thread_tag, jlong tid, jint depth, | |
1992 jmethodID method, jlocation bci, jint slot, oop o); | |
1993 | |
1994 // functions to report references | |
1995 static inline bool report_array_element_reference(oop referrer, oop referree, jint index); | |
1996 static inline bool report_class_reference(oop referrer, oop referree); | |
1997 static inline bool report_class_loader_reference(oop referrer, oop referree); | |
1998 static inline bool report_signers_reference(oop referrer, oop referree); | |
1999 static inline bool report_protection_domain_reference(oop referrer, oop referree); | |
2000 static inline bool report_superclass_reference(oop referrer, oop referree); | |
2001 static inline bool report_interface_reference(oop referrer, oop referree); | |
2002 static inline bool report_static_field_reference(oop referrer, oop referree, jint slot); | |
2003 static inline bool report_field_reference(oop referrer, oop referree, jint slot); | |
2004 static inline bool report_constant_pool_reference(oop referrer, oop referree, jint index); | |
2005 static inline bool report_primitive_array_values(oop array); | |
2006 static inline bool report_string_value(oop str); | |
2007 static inline bool report_primitive_instance_field(oop o, jint index, address value, char type); | |
2008 static inline bool report_primitive_static_field(oop o, jint index, address value, char type); | |
2009 }; | |
2010 | |
2011 // statics | |
2012 int CallbackInvoker::_heap_walk_type; | |
2013 BasicHeapWalkContext CallbackInvoker::_basic_context; | |
2014 AdvancedHeapWalkContext CallbackInvoker::_advanced_context; | |
2015 JvmtiTagMap* CallbackInvoker::_tag_map; | |
2016 const void* CallbackInvoker::_user_data; | |
2017 GrowableArray<oop>* CallbackInvoker::_visit_stack; | |
2018 | |
2019 // initialize for basic heap walk (IterateOverReachableObjects et al) | |
2020 void CallbackInvoker::initialize_for_basic_heap_walk(JvmtiTagMap* tag_map, | |
2021 GrowableArray<oop>* visit_stack, | |
2022 const void* user_data, | |
2023 BasicHeapWalkContext context) { | |
2024 _tag_map = tag_map; | |
2025 _visit_stack = visit_stack; | |
2026 _user_data = user_data; | |
2027 _basic_context = context; | |
2028 _advanced_context.invalidate(); // will trigger assertion if used | |
2029 _heap_walk_type = basic; | |
2030 } | |
2031 | |
2032 // initialize for advanced heap walk (FollowReferences) | |
2033 void CallbackInvoker::initialize_for_advanced_heap_walk(JvmtiTagMap* tag_map, | |
2034 GrowableArray<oop>* visit_stack, | |
2035 const void* user_data, | |
2036 AdvancedHeapWalkContext context) { | |
2037 _tag_map = tag_map; | |
2038 _visit_stack = visit_stack; | |
2039 _user_data = user_data; | |
2040 _advanced_context = context; | |
2041 _basic_context.invalidate(); // will trigger assertion if used | |
2042 _heap_walk_type = advanced; | |
2043 } | |
2044 | |
2045 | |
2046 // invoke basic style heap root callback | |
2047 inline bool CallbackInvoker::invoke_basic_heap_root_callback(jvmtiHeapRootKind root_kind, oop obj) { | |
2048 assert(ServiceUtil::visible_oop(obj), "checking"); | |
2049 | |
2050 // if we heap roots should be reported | |
2051 jvmtiHeapRootCallback cb = basic_context()->heap_root_callback(); | |
2052 if (cb == NULL) { | |
2053 return check_for_visit(obj); | |
2054 } | |
2055 | |
2056 CallbackWrapper wrapper(tag_map(), obj); | |
2057 jvmtiIterationControl control = (*cb)(root_kind, | |
2058 wrapper.klass_tag(), | |
2059 wrapper.obj_size(), | |
2060 wrapper.obj_tag_p(), | |
2061 (void*)user_data()); | |
2062 // push root to visit stack when following references | |
2063 if (control == JVMTI_ITERATION_CONTINUE && | |
2064 basic_context()->object_ref_callback() != NULL) { | |
2065 visit_stack()->push(obj); | |
2066 } | |
2067 return control != JVMTI_ITERATION_ABORT; | |
2068 } | |
2069 | |
2070 // invoke basic style stack ref callback | |
2071 inline bool CallbackInvoker::invoke_basic_stack_ref_callback(jvmtiHeapRootKind root_kind, | |
2072 jlong thread_tag, | |
2073 jint depth, | |
2074 jmethodID method, | |
2075 jint slot, | |
2076 oop obj) { | |
2077 assert(ServiceUtil::visible_oop(obj), "checking"); | |
2078 | |
2079 // if we stack refs should be reported | |
2080 jvmtiStackReferenceCallback cb = basic_context()->stack_ref_callback(); | |
2081 if (cb == NULL) { | |
2082 return check_for_visit(obj); | |
2083 } | |
2084 | |
2085 CallbackWrapper wrapper(tag_map(), obj); | |
2086 jvmtiIterationControl control = (*cb)(root_kind, | |
2087 wrapper.klass_tag(), | |
2088 wrapper.obj_size(), | |
2089 wrapper.obj_tag_p(), | |
2090 thread_tag, | |
2091 depth, | |
2092 method, | |
2093 slot, | |
2094 (void*)user_data()); | |
2095 // push root to visit stack when following references | |
2096 if (control == JVMTI_ITERATION_CONTINUE && | |
2097 basic_context()->object_ref_callback() != NULL) { | |
2098 visit_stack()->push(obj); | |
2099 } | |
2100 return control != JVMTI_ITERATION_ABORT; | |
2101 } | |
2102 | |
2103 // invoke basic style object reference callback | |
2104 inline bool CallbackInvoker::invoke_basic_object_reference_callback(jvmtiObjectReferenceKind ref_kind, | |
2105 oop referrer, | |
2106 oop referree, | |
2107 jint index) { | |
2108 | |
2109 assert(ServiceUtil::visible_oop(referrer), "checking"); | |
2110 assert(ServiceUtil::visible_oop(referree), "checking"); | |
2111 | |
2112 BasicHeapWalkContext* context = basic_context(); | |
2113 | |
2114 // callback requires the referrer's tag. If it's the same referrer | |
2115 // as the last call then we use the cached value. | |
2116 jlong referrer_tag; | |
2117 if (referrer == context->last_referrer()) { | |
2118 referrer_tag = context->last_referrer_tag(); | |
2119 } else { | |
2120 referrer_tag = tag_for(tag_map(), klassOop_if_java_lang_Class(referrer)); | |
2121 } | |
2122 | |
2123 // do the callback | |
2124 CallbackWrapper wrapper(tag_map(), referree); | |
2125 jvmtiObjectReferenceCallback cb = context->object_ref_callback(); | |
2126 jvmtiIterationControl control = (*cb)(ref_kind, | |
2127 wrapper.klass_tag(), | |
2128 wrapper.obj_size(), | |
2129 wrapper.obj_tag_p(), | |
2130 referrer_tag, | |
2131 index, | |
2132 (void*)user_data()); | |
2133 | |
2134 // record referrer and referrer tag. For self-references record the | |
2135 // tag value from the callback as this might differ from referrer_tag. | |
2136 context->set_last_referrer(referrer); | |
2137 if (referrer == referree) { | |
2138 context->set_last_referrer_tag(*wrapper.obj_tag_p()); | |
2139 } else { | |
2140 context->set_last_referrer_tag(referrer_tag); | |
2141 } | |
2142 | |
2143 if (control == JVMTI_ITERATION_CONTINUE) { | |
2144 return check_for_visit(referree); | |
2145 } else { | |
2146 return control != JVMTI_ITERATION_ABORT; | |
2147 } | |
2148 } | |
2149 | |
2150 // invoke advanced style heap root callback | |
2151 inline bool CallbackInvoker::invoke_advanced_heap_root_callback(jvmtiHeapReferenceKind ref_kind, | |
2152 oop obj) { | |
2153 assert(ServiceUtil::visible_oop(obj), "checking"); | |
2154 | |
2155 AdvancedHeapWalkContext* context = advanced_context(); | |
2156 | |
2157 // check that callback is provided | |
2158 jvmtiHeapReferenceCallback cb = context->heap_reference_callback(); | |
2159 if (cb == NULL) { | |
2160 return check_for_visit(obj); | |
2161 } | |
2162 | |
2163 // apply class filter | |
2164 if (is_filtered_by_klass_filter(obj, context->klass_filter())) { | |
2165 return check_for_visit(obj); | |
2166 } | |
2167 | |
2168 // setup the callback wrapper | |
2169 CallbackWrapper wrapper(tag_map(), obj); | |
2170 | |
2171 // apply tag filter | |
2172 if (is_filtered_by_heap_filter(wrapper.obj_tag(), | |
2173 wrapper.klass_tag(), | |
2174 context->heap_filter())) { | |
2175 return check_for_visit(obj); | |
2176 } | |
2177 | |
2178 // for arrays we need the length, otherwise -1 | |
2179 jint len = (jint)(obj->is_array() ? arrayOop(obj)->length() : -1); | |
2180 | |
2181 // invoke the callback | |
2182 jint res = (*cb)(ref_kind, | |
2183 NULL, // referrer info | |
2184 wrapper.klass_tag(), | |
2185 0, // referrer_class_tag is 0 for heap root | |
2186 wrapper.obj_size(), | |
2187 wrapper.obj_tag_p(), | |
2188 NULL, // referrer_tag_p | |
2189 len, | |
2190 (void*)user_data()); | |
2191 if (res & JVMTI_VISIT_ABORT) { | |
2192 return false;// referrer class tag | |
2193 } | |
2194 if (res & JVMTI_VISIT_OBJECTS) { | |
2195 check_for_visit(obj); | |
2196 } | |
2197 return true; | |
2198 } | |
2199 | |
2200 // report a reference from a thread stack to an object | |
2201 inline bool CallbackInvoker::invoke_advanced_stack_ref_callback(jvmtiHeapReferenceKind ref_kind, | |
2202 jlong thread_tag, | |
2203 jlong tid, | |
2204 int depth, | |
2205 jmethodID method, | |
2206 jlocation bci, | |
2207 jint slot, | |
2208 oop obj) { | |
2209 assert(ServiceUtil::visible_oop(obj), "checking"); | |
2210 | |
2211 AdvancedHeapWalkContext* context = advanced_context(); | |
2212 | |
2213 // check that callback is provider | |
2214 jvmtiHeapReferenceCallback cb = context->heap_reference_callback(); | |
2215 if (cb == NULL) { | |
2216 return check_for_visit(obj); | |
2217 } | |
2218 | |
2219 // apply class filter | |
2220 if (is_filtered_by_klass_filter(obj, context->klass_filter())) { | |
2221 return check_for_visit(obj); | |
2222 } | |
2223 | |
2224 // setup the callback wrapper | |
2225 CallbackWrapper wrapper(tag_map(), obj); | |
2226 | |
2227 // apply tag filter | |
2228 if (is_filtered_by_heap_filter(wrapper.obj_tag(), | |
2229 wrapper.klass_tag(), | |
2230 context->heap_filter())) { | |
2231 return check_for_visit(obj); | |
2232 } | |
2233 | |
2234 // setup the referrer info | |
2235 jvmtiHeapReferenceInfo reference_info; | |
2236 reference_info.stack_local.thread_tag = thread_tag; | |
2237 reference_info.stack_local.thread_id = tid; | |
2238 reference_info.stack_local.depth = depth; | |
2239 reference_info.stack_local.method = method; | |
2240 reference_info.stack_local.location = bci; | |
2241 reference_info.stack_local.slot = slot; | |
2242 | |
2243 // for arrays we need the length, otherwise -1 | |
2244 jint len = (jint)(obj->is_array() ? arrayOop(obj)->length() : -1); | |
2245 | |
2246 // call into the agent | |
2247 int res = (*cb)(ref_kind, | |
2248 &reference_info, | |
2249 wrapper.klass_tag(), | |
2250 0, // referrer_class_tag is 0 for heap root (stack) | |
2251 wrapper.obj_size(), | |
2252 wrapper.obj_tag_p(), | |
2253 NULL, // referrer_tag is 0 for root | |
2254 len, | |
2255 (void*)user_data()); | |
2256 | |
2257 if (res & JVMTI_VISIT_ABORT) { | |
2258 return false; | |
2259 } | |
2260 if (res & JVMTI_VISIT_OBJECTS) { | |
2261 check_for_visit(obj); | |
2262 } | |
2263 return true; | |
2264 } | |
2265 | |
2266 // This mask is used to pass reference_info to a jvmtiHeapReferenceCallback | |
2267 // only for ref_kinds defined by the JVM TI spec. Otherwise, NULL is passed. | |
2268 #define REF_INFO_MASK ((1 << JVMTI_HEAP_REFERENCE_FIELD) \ | |
2269 | (1 << JVMTI_HEAP_REFERENCE_STATIC_FIELD) \ | |
2270 | (1 << JVMTI_HEAP_REFERENCE_ARRAY_ELEMENT) \ | |
2271 | (1 << JVMTI_HEAP_REFERENCE_CONSTANT_POOL) \ | |
2272 | (1 << JVMTI_HEAP_REFERENCE_STACK_LOCAL) \ | |
2273 | (1 << JVMTI_HEAP_REFERENCE_JNI_LOCAL)) | |
2274 | |
2275 // invoke the object reference callback to report a reference | |
2276 inline bool CallbackInvoker::invoke_advanced_object_reference_callback(jvmtiHeapReferenceKind ref_kind, | |
2277 oop referrer, | |
2278 oop obj, | |
2279 jint index) | |
2280 { | |
2281 // field index is only valid field in reference_info | |
2282 static jvmtiHeapReferenceInfo reference_info = { 0 }; | |
2283 | |
2284 assert(ServiceUtil::visible_oop(referrer), "checking"); | |
2285 assert(ServiceUtil::visible_oop(obj), "checking"); | |
2286 | |
2287 AdvancedHeapWalkContext* context = advanced_context(); | |
2288 | |
2289 // check that callback is provider | |
2290 jvmtiHeapReferenceCallback cb = context->heap_reference_callback(); | |
2291 if (cb == NULL) { | |
2292 return check_for_visit(obj); | |
2293 } | |
2294 | |
2295 // apply class filter | |
2296 if (is_filtered_by_klass_filter(obj, context->klass_filter())) { | |
2297 return check_for_visit(obj); | |
2298 } | |
2299 | |
2300 // setup the callback wrapper | |
2301 TwoOopCallbackWrapper wrapper(tag_map(), referrer, obj); | |
2302 | |
2303 // apply tag filter | |
2304 if (is_filtered_by_heap_filter(wrapper.obj_tag(), | |
2305 wrapper.klass_tag(), | |
2306 context->heap_filter())) { | |
2307 return check_for_visit(obj); | |
2308 } | |
2309 | |
2310 // field index is only valid field in reference_info | |
2311 reference_info.field.index = index; | |
2312 | |
2313 // for arrays we need the length, otherwise -1 | |
2314 jint len = (jint)(obj->is_array() ? arrayOop(obj)->length() : -1); | |
2315 | |
2316 // invoke the callback | |
2317 int res = (*cb)(ref_kind, | |
2318 (REF_INFO_MASK & (1 << ref_kind)) ? &reference_info : NULL, | |
2319 wrapper.klass_tag(), | |
2320 wrapper.referrer_klass_tag(), | |
2321 wrapper.obj_size(), | |
2322 wrapper.obj_tag_p(), | |
2323 wrapper.referrer_tag_p(), | |
2324 len, | |
2325 (void*)user_data()); | |
2326 | |
2327 if (res & JVMTI_VISIT_ABORT) { | |
2328 return false; | |
2329 } | |
2330 if (res & JVMTI_VISIT_OBJECTS) { | |
2331 check_for_visit(obj); | |
2332 } | |
2333 return true; | |
2334 } | |
2335 | |
2336 // report a "simple root" | |
2337 inline bool CallbackInvoker::report_simple_root(jvmtiHeapReferenceKind kind, oop obj) { | |
2338 assert(kind != JVMTI_HEAP_REFERENCE_STACK_LOCAL && | |
2339 kind != JVMTI_HEAP_REFERENCE_JNI_LOCAL, "not a simple root"); | |
2340 assert(ServiceUtil::visible_oop(obj), "checking"); | |
2341 | |
2342 if (is_basic_heap_walk()) { | |
2343 // map to old style root kind | |
2344 jvmtiHeapRootKind root_kind = toJvmtiHeapRootKind(kind); | |
2345 return invoke_basic_heap_root_callback(root_kind, obj); | |
2346 } else { | |
2347 assert(is_advanced_heap_walk(), "wrong heap walk type"); | |
2348 return invoke_advanced_heap_root_callback(kind, obj); | |
2349 } | |
2350 } | |
2351 | |
2352 | |
2353 // invoke the primitive array values | |
2354 inline bool CallbackInvoker::report_primitive_array_values(oop obj) { | |
2355 assert(obj->is_typeArray(), "not a primitive array"); | |
2356 | |
2357 AdvancedHeapWalkContext* context = advanced_context(); | |
2358 assert(context->array_primitive_value_callback() != NULL, "no callback"); | |
2359 | |
2360 // apply class filter | |
2361 if (is_filtered_by_klass_filter(obj, context->klass_filter())) { | |
2362 return true; | |
2363 } | |
2364 | |
2365 CallbackWrapper wrapper(tag_map(), obj); | |
2366 | |
2367 // apply tag filter | |
2368 if (is_filtered_by_heap_filter(wrapper.obj_tag(), | |
2369 wrapper.klass_tag(), | |
2370 context->heap_filter())) { | |
2371 return true; | |
2372 } | |
2373 | |
2374 // invoke the callback | |
2375 int res = invoke_array_primitive_value_callback(context->array_primitive_value_callback(), | |
2376 &wrapper, | |
2377 obj, | |
2378 (void*)user_data()); | |
2379 return (!(res & JVMTI_VISIT_ABORT)); | |
2380 } | |
2381 | |
2382 // invoke the string value callback | |
2383 inline bool CallbackInvoker::report_string_value(oop str) { | |
2384 assert(str->klass() == SystemDictionary::string_klass(), "not a string"); | |
2385 | |
2386 AdvancedHeapWalkContext* context = advanced_context(); | |
2387 assert(context->string_primitive_value_callback() != NULL, "no callback"); | |
2388 | |
2389 // apply class filter | |
2390 if (is_filtered_by_klass_filter(str, context->klass_filter())) { | |
2391 return true; | |
2392 } | |
2393 | |
2394 CallbackWrapper wrapper(tag_map(), str); | |
2395 | |
2396 // apply tag filter | |
2397 if (is_filtered_by_heap_filter(wrapper.obj_tag(), | |
2398 wrapper.klass_tag(), | |
2399 context->heap_filter())) { | |
2400 return true; | |
2401 } | |
2402 | |
2403 // invoke the callback | |
2404 int res = invoke_string_value_callback(context->string_primitive_value_callback(), | |
2405 &wrapper, | |
2406 str, | |
2407 (void*)user_data()); | |
2408 return (!(res & JVMTI_VISIT_ABORT)); | |
2409 } | |
2410 | |
2411 // invoke the primitive field callback | |
2412 inline bool CallbackInvoker::report_primitive_field(jvmtiHeapReferenceKind ref_kind, | |
2413 oop obj, | |
2414 jint index, | |
2415 address addr, | |
2416 char type) | |
2417 { | |
2418 // for primitive fields only the index will be set | |
2419 static jvmtiHeapReferenceInfo reference_info = { 0 }; | |
2420 | |
2421 AdvancedHeapWalkContext* context = advanced_context(); | |
2422 assert(context->primitive_field_callback() != NULL, "no callback"); | |
2423 | |
2424 // apply class filter | |
2425 if (is_filtered_by_klass_filter(obj, context->klass_filter())) { | |
2426 return true; | |
2427 } | |
2428 | |
2429 CallbackWrapper wrapper(tag_map(), obj); | |
2430 | |
2431 // apply tag filter | |
2432 if (is_filtered_by_heap_filter(wrapper.obj_tag(), | |
2433 wrapper.klass_tag(), | |
2434 context->heap_filter())) { | |
2435 return true; | |
2436 } | |
2437 | |
2438 // the field index in the referrer | |
2439 reference_info.field.index = index; | |
2440 | |
2441 // map the type | |
2442 jvmtiPrimitiveType value_type = (jvmtiPrimitiveType)type; | |
2443 | |
2444 // setup the jvalue | |
2445 jvalue value; | |
2446 copy_to_jvalue(&value, addr, value_type); | |
2447 | |
2448 jvmtiPrimitiveFieldCallback cb = context->primitive_field_callback(); | |
2449 int res = (*cb)(ref_kind, | |
2450 &reference_info, | |
2451 wrapper.klass_tag(), | |
2452 wrapper.obj_tag_p(), | |
2453 value, | |
2454 value_type, | |
2455 (void*)user_data()); | |
2456 return (!(res & JVMTI_VISIT_ABORT)); | |
2457 } | |
2458 | |
2459 | |
2460 // instance field | |
2461 inline bool CallbackInvoker::report_primitive_instance_field(oop obj, | |
2462 jint index, | |
2463 address value, | |
2464 char type) { | |
2465 return report_primitive_field(JVMTI_HEAP_REFERENCE_FIELD, | |
2466 obj, | |
2467 index, | |
2468 value, | |
2469 type); | |
2470 } | |
2471 | |
2472 // static field | |
2473 inline bool CallbackInvoker::report_primitive_static_field(oop obj, | |
2474 jint index, | |
2475 address value, | |
2476 char type) { | |
2477 return report_primitive_field(JVMTI_HEAP_REFERENCE_STATIC_FIELD, | |
2478 obj, | |
2479 index, | |
2480 value, | |
2481 type); | |
2482 } | |
2483 | |
2484 // report a JNI local (root object) to the profiler | |
2485 inline bool CallbackInvoker::report_jni_local_root(jlong thread_tag, jlong tid, jint depth, jmethodID m, oop obj) { | |
2486 if (is_basic_heap_walk()) { | |
2487 return invoke_basic_stack_ref_callback(JVMTI_HEAP_ROOT_JNI_LOCAL, | |
2488 thread_tag, | |
2489 depth, | |
2490 m, | |
2491 -1, | |
2492 obj); | |
2493 } else { | |
2494 return invoke_advanced_stack_ref_callback(JVMTI_HEAP_REFERENCE_JNI_LOCAL, | |
2495 thread_tag, tid, | |
2496 depth, | |
2497 m, | |
2498 (jlocation)-1, | |
2499 -1, | |
2500 obj); | |
2501 } | |
2502 } | |
2503 | |
2504 | |
2505 // report a local (stack reference, root object) | |
2506 inline bool CallbackInvoker::report_stack_ref_root(jlong thread_tag, | |
2507 jlong tid, | |
2508 jint depth, | |
2509 jmethodID method, | |
2510 jlocation bci, | |
2511 jint slot, | |
2512 oop obj) { | |
2513 if (is_basic_heap_walk()) { | |
2514 return invoke_basic_stack_ref_callback(JVMTI_HEAP_ROOT_STACK_LOCAL, | |
2515 thread_tag, | |
2516 depth, | |
2517 method, | |
2518 slot, | |
2519 obj); | |
2520 } else { | |
2521 return invoke_advanced_stack_ref_callback(JVMTI_HEAP_REFERENCE_STACK_LOCAL, | |
2522 thread_tag, | |
2523 tid, | |
2524 depth, | |
2525 method, | |
2526 bci, | |
2527 slot, | |
2528 obj); | |
2529 } | |
2530 } | |
2531 | |
2532 // report an object referencing a class. | |
2533 inline bool CallbackInvoker::report_class_reference(oop referrer, oop referree) { | |
2534 if (is_basic_heap_walk()) { | |
2535 return invoke_basic_object_reference_callback(JVMTI_REFERENCE_CLASS, referrer, referree, -1); | |
2536 } else { | |
2537 return invoke_advanced_object_reference_callback(JVMTI_HEAP_REFERENCE_CLASS, referrer, referree, -1); | |
2538 } | |
2539 } | |
2540 | |
2541 // report a class referencing its class loader. | |
2542 inline bool CallbackInvoker::report_class_loader_reference(oop referrer, oop referree) { | |
2543 if (is_basic_heap_walk()) { | |
2544 return invoke_basic_object_reference_callback(JVMTI_REFERENCE_CLASS_LOADER, referrer, referree, -1); | |
2545 } else { | |
2546 return invoke_advanced_object_reference_callback(JVMTI_HEAP_REFERENCE_CLASS_LOADER, referrer, referree, -1); | |
2547 } | |
2548 } | |
2549 | |
2550 // report a class referencing its signers. | |
2551 inline bool CallbackInvoker::report_signers_reference(oop referrer, oop referree) { | |
2552 if (is_basic_heap_walk()) { | |
2553 return invoke_basic_object_reference_callback(JVMTI_REFERENCE_SIGNERS, referrer, referree, -1); | |
2554 } else { | |
2555 return invoke_advanced_object_reference_callback(JVMTI_HEAP_REFERENCE_SIGNERS, referrer, referree, -1); | |
2556 } | |
2557 } | |
2558 | |
2559 // report a class referencing its protection domain.. | |
2560 inline bool CallbackInvoker::report_protection_domain_reference(oop referrer, oop referree) { | |
2561 if (is_basic_heap_walk()) { | |
2562 return invoke_basic_object_reference_callback(JVMTI_REFERENCE_PROTECTION_DOMAIN, referrer, referree, -1); | |
2563 } else { | |
2564 return invoke_advanced_object_reference_callback(JVMTI_HEAP_REFERENCE_PROTECTION_DOMAIN, referrer, referree, -1); | |
2565 } | |
2566 } | |
2567 | |
2568 // report a class referencing its superclass. | |
2569 inline bool CallbackInvoker::report_superclass_reference(oop referrer, oop referree) { | |
2570 if (is_basic_heap_walk()) { | |
2571 // Send this to be consistent with past implementation | |
2572 return invoke_basic_object_reference_callback(JVMTI_REFERENCE_CLASS, referrer, referree, -1); | |
2573 } else { | |
2574 return invoke_advanced_object_reference_callback(JVMTI_HEAP_REFERENCE_SUPERCLASS, referrer, referree, -1); | |
2575 } | |
2576 } | |
2577 | |
2578 // report a class referencing one of its interfaces. | |
2579 inline bool CallbackInvoker::report_interface_reference(oop referrer, oop referree) { | |
2580 if (is_basic_heap_walk()) { | |
2581 return invoke_basic_object_reference_callback(JVMTI_REFERENCE_INTERFACE, referrer, referree, -1); | |
2582 } else { | |
2583 return invoke_advanced_object_reference_callback(JVMTI_HEAP_REFERENCE_INTERFACE, referrer, referree, -1); | |
2584 } | |
2585 } | |
2586 | |
2587 // report a class referencing one of its static fields. | |
2588 inline bool CallbackInvoker::report_static_field_reference(oop referrer, oop referree, jint slot) { | |
2589 if (is_basic_heap_walk()) { | |
2590 return invoke_basic_object_reference_callback(JVMTI_REFERENCE_STATIC_FIELD, referrer, referree, slot); | |
2591 } else { | |
2592 return invoke_advanced_object_reference_callback(JVMTI_HEAP_REFERENCE_STATIC_FIELD, referrer, referree, slot); | |
2593 } | |
2594 } | |
2595 | |
2596 // report an array referencing an element object | |
2597 inline bool CallbackInvoker::report_array_element_reference(oop referrer, oop referree, jint index) { | |
2598 if (is_basic_heap_walk()) { | |
2599 return invoke_basic_object_reference_callback(JVMTI_REFERENCE_ARRAY_ELEMENT, referrer, referree, index); | |
2600 } else { | |
2601 return invoke_advanced_object_reference_callback(JVMTI_HEAP_REFERENCE_ARRAY_ELEMENT, referrer, referree, index); | |
2602 } | |
2603 } | |
2604 | |
2605 // report an object referencing an instance field object | |
2606 inline bool CallbackInvoker::report_field_reference(oop referrer, oop referree, jint slot) { | |
2607 if (is_basic_heap_walk()) { | |
2608 return invoke_basic_object_reference_callback(JVMTI_REFERENCE_FIELD, referrer, referree, slot); | |
2609 } else { | |
2610 return invoke_advanced_object_reference_callback(JVMTI_HEAP_REFERENCE_FIELD, referrer, referree, slot); | |
2611 } | |
2612 } | |
2613 | |
2614 // report an array referencing an element object | |
2615 inline bool CallbackInvoker::report_constant_pool_reference(oop referrer, oop referree, jint index) { | |
2616 if (is_basic_heap_walk()) { | |
2617 return invoke_basic_object_reference_callback(JVMTI_REFERENCE_CONSTANT_POOL, referrer, referree, index); | |
2618 } else { | |
2619 return invoke_advanced_object_reference_callback(JVMTI_HEAP_REFERENCE_CONSTANT_POOL, referrer, referree, index); | |
2620 } | |
2621 } | |
2622 | |
2623 // A supporting closure used to process simple roots | |
2624 class SimpleRootsClosure : public OopClosure { | |
2625 private: | |
2626 jvmtiHeapReferenceKind _kind; | |
2627 bool _continue; | |
2628 | |
2629 jvmtiHeapReferenceKind root_kind() { return _kind; } | |
2630 | |
2631 public: | |
2632 void set_kind(jvmtiHeapReferenceKind kind) { | |
2633 _kind = kind; | |
2634 _continue = true; | |
2635 } | |
2636 | |
2637 inline bool stopped() { | |
2638 return !_continue; | |
2639 } | |
2640 | |
2641 void do_oop(oop* obj_p) { | |
2642 // iteration has terminated | |
2643 if (stopped()) { | |
2644 return; | |
2645 } | |
2646 | |
2647 // ignore null or deleted handles | |
2648 oop o = *obj_p; | |
2649 if (o == NULL || o == JNIHandles::deleted_handle()) { | |
2650 return; | |
2651 } | |
2652 | |
2653 jvmtiHeapReferenceKind kind = root_kind(); | |
2654 | |
2655 // many roots are Klasses so we use the java mirror | |
2656 if (o->is_klass()) { | |
2657 klassOop k = (klassOop)o; | |
2658 o = Klass::cast(k)->java_mirror(); | |
2659 } else { | |
2660 | |
2661 // SystemDictionary::always_strong_oops_do reports the application | |
2662 // class loader as a root. We want this root to be reported as | |
2663 // a root kind of "OTHER" rather than "SYSTEM_CLASS". | |
2664 if (o->is_instance() && root_kind() == JVMTI_HEAP_REFERENCE_SYSTEM_CLASS) { | |
2665 kind = JVMTI_HEAP_REFERENCE_OTHER; | |
2666 } | |
2667 } | |
2668 | |
2669 // some objects are ignored - in the case of simple | |
2670 // roots it's mostly symbolOops that we are skipping | |
2671 // here. | |
2672 if (!ServiceUtil::visible_oop(o)) { | |
2673 return; | |
2674 } | |
2675 | |
2676 // invoke the callback | |
2677 _continue = CallbackInvoker::report_simple_root(kind, o); | |
2678 | |
2679 } | |
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2680 virtual void do_oop(narrowOop* obj_p) { ShouldNotReachHere(); } |
0 | 2681 }; |
2682 | |
2683 // A supporting closure used to process JNI locals | |
2684 class JNILocalRootsClosure : public OopClosure { | |
2685 private: | |
2686 jlong _thread_tag; | |
2687 jlong _tid; | |
2688 jint _depth; | |
2689 jmethodID _method; | |
2690 bool _continue; | |
2691 public: | |
2692 void set_context(jlong thread_tag, jlong tid, jint depth, jmethodID method) { | |
2693 _thread_tag = thread_tag; | |
2694 _tid = tid; | |
2695 _depth = depth; | |
2696 _method = method; | |
2697 _continue = true; | |
2698 } | |
2699 | |
2700 inline bool stopped() { | |
2701 return !_continue; | |
2702 } | |
2703 | |
2704 void do_oop(oop* obj_p) { | |
2705 // iteration has terminated | |
2706 if (stopped()) { | |
2707 return; | |
2708 } | |
2709 | |
2710 // ignore null or deleted handles | |
2711 oop o = *obj_p; | |
2712 if (o == NULL || o == JNIHandles::deleted_handle()) { | |
2713 return; | |
2714 } | |
2715 | |
2716 if (!ServiceUtil::visible_oop(o)) { | |
2717 return; | |
2718 } | |
2719 | |
2720 // invoke the callback | |
2721 _continue = CallbackInvoker::report_jni_local_root(_thread_tag, _tid, _depth, _method, o); | |
2722 } | |
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|
2723 virtual void do_oop(narrowOop* obj_p) { ShouldNotReachHere(); } |
0 | 2724 }; |
2725 | |
2726 | |
2727 // A VM operation to iterate over objects that are reachable from | |
2728 // a set of roots or an initial object. | |
2729 // | |
2730 // For VM_HeapWalkOperation the set of roots used is :- | |
2731 // | |
2732 // - All JNI global references | |
2733 // - All inflated monitors | |
2734 // - All classes loaded by the boot class loader (or all classes | |
2735 // in the event that class unloading is disabled) | |
2736 // - All java threads | |
2737 // - For each java thread then all locals and JNI local references | |
2738 // on the thread's execution stack | |
2739 // - All visible/explainable objects from Universes::oops_do | |
2740 // | |
2741 class VM_HeapWalkOperation: public VM_Operation { | |
2742 private: | |
2743 enum { | |
2744 initial_visit_stack_size = 4000 | |
2745 }; | |
2746 | |
2747 bool _is_advanced_heap_walk; // indicates FollowReferences | |
2748 JvmtiTagMap* _tag_map; | |
2749 Handle _initial_object; | |
2750 GrowableArray<oop>* _visit_stack; // the visit stack | |
2751 | |
2752 bool _collecting_heap_roots; // are we collecting roots | |
2753 bool _following_object_refs; // are we following object references | |
2754 | |
2755 bool _reporting_primitive_fields; // optional reporting | |
2756 bool _reporting_primitive_array_values; | |
2757 bool _reporting_string_values; | |
2758 | |
2759 GrowableArray<oop>* create_visit_stack() { | |
2760 return new (ResourceObj::C_HEAP) GrowableArray<oop>(initial_visit_stack_size, true); | |
2761 } | |
2762 | |
2763 // accessors | |
2764 bool is_advanced_heap_walk() const { return _is_advanced_heap_walk; } | |
2765 JvmtiTagMap* tag_map() const { return _tag_map; } | |
2766 Handle initial_object() const { return _initial_object; } | |
2767 | |
2768 bool is_following_references() const { return _following_object_refs; } | |
2769 | |
2770 bool is_reporting_primitive_fields() const { return _reporting_primitive_fields; } | |
2771 bool is_reporting_primitive_array_values() const { return _reporting_primitive_array_values; } | |
2772 bool is_reporting_string_values() const { return _reporting_string_values; } | |
2773 | |
2774 GrowableArray<oop>* visit_stack() const { return _visit_stack; } | |
2775 | |
2776 // iterate over the various object types | |
2777 inline bool iterate_over_array(oop o); | |
2778 inline bool iterate_over_type_array(oop o); | |
2779 inline bool iterate_over_class(klassOop o); | |
2780 inline bool iterate_over_object(oop o); | |
2781 | |
2782 // root collection | |
2783 inline bool collect_simple_roots(); | |
2784 inline bool collect_stack_roots(); | |
2785 inline bool collect_stack_roots(JavaThread* java_thread, JNILocalRootsClosure* blk); | |
2786 | |
2787 // visit an object | |
2788 inline bool visit(oop o); | |
2789 | |
2790 public: | |
2791 VM_HeapWalkOperation(JvmtiTagMap* tag_map, | |
2792 Handle initial_object, | |
2793 BasicHeapWalkContext callbacks, | |
2794 const void* user_data); | |
2795 | |
2796 VM_HeapWalkOperation(JvmtiTagMap* tag_map, | |
2797 Handle initial_object, | |
2798 AdvancedHeapWalkContext callbacks, | |
2799 const void* user_data); | |
2800 | |
2801 ~VM_HeapWalkOperation(); | |
2802 | |
2803 VMOp_Type type() const { return VMOp_HeapWalkOperation; } | |
2804 void doit(); | |
2805 }; | |
2806 | |
2807 | |
2808 VM_HeapWalkOperation::VM_HeapWalkOperation(JvmtiTagMap* tag_map, | |
2809 Handle initial_object, | |
2810 BasicHeapWalkContext callbacks, | |
2811 const void* user_data) { | |
2812 _is_advanced_heap_walk = false; | |
2813 _tag_map = tag_map; | |
2814 _initial_object = initial_object; | |
2815 _following_object_refs = (callbacks.object_ref_callback() != NULL); | |
2816 _reporting_primitive_fields = false; | |
2817 _reporting_primitive_array_values = false; | |
2818 _reporting_string_values = false; | |
2819 _visit_stack = create_visit_stack(); | |
2820 | |
2821 | |
2822 CallbackInvoker::initialize_for_basic_heap_walk(tag_map, _visit_stack, user_data, callbacks); | |
2823 } | |
2824 | |
2825 VM_HeapWalkOperation::VM_HeapWalkOperation(JvmtiTagMap* tag_map, | |
2826 Handle initial_object, | |
2827 AdvancedHeapWalkContext callbacks, | |
2828 const void* user_data) { | |
2829 _is_advanced_heap_walk = true; | |
2830 _tag_map = tag_map; | |
2831 _initial_object = initial_object; | |
2832 _following_object_refs = true; | |
2833 _reporting_primitive_fields = (callbacks.primitive_field_callback() != NULL);; | |
2834 _reporting_primitive_array_values = (callbacks.array_primitive_value_callback() != NULL);; | |
2835 _reporting_string_values = (callbacks.string_primitive_value_callback() != NULL);; | |
2836 _visit_stack = create_visit_stack(); | |
2837 | |
2838 CallbackInvoker::initialize_for_advanced_heap_walk(tag_map, _visit_stack, user_data, callbacks); | |
2839 } | |
2840 | |
2841 VM_HeapWalkOperation::~VM_HeapWalkOperation() { | |
2842 if (_following_object_refs) { | |
2843 assert(_visit_stack != NULL, "checking"); | |
2844 delete _visit_stack; | |
2845 _visit_stack = NULL; | |
2846 } | |
2847 } | |
2848 | |
2849 // an array references its class and has a reference to | |
2850 // each element in the array | |
2851 inline bool VM_HeapWalkOperation::iterate_over_array(oop o) { | |
2852 objArrayOop array = objArrayOop(o); | |
2853 if (array->klass() == Universe::systemObjArrayKlassObj()) { | |
2854 // filtered out | |
2855 return true; | |
2856 } | |
2857 | |
2858 // array reference to its class | |
2859 oop mirror = objArrayKlass::cast(array->klass())->java_mirror(); | |
2860 if (!CallbackInvoker::report_class_reference(o, mirror)) { | |
2861 return false; | |
2862 } | |
2863 | |
2864 // iterate over the array and report each reference to a | |
2865 // non-null element | |
2866 for (int index=0; index<array->length(); index++) { | |
2867 oop elem = array->obj_at(index); | |
2868 if (elem == NULL) { | |
2869 continue; | |
2870 } | |
2871 | |
2872 // report the array reference o[index] = elem | |
2873 if (!CallbackInvoker::report_array_element_reference(o, elem, index)) { | |
2874 return false; | |
2875 } | |
2876 } | |
2877 return true; | |
2878 } | |
2879 | |
2880 // a type array references its class | |
2881 inline bool VM_HeapWalkOperation::iterate_over_type_array(oop o) { | |
2882 klassOop k = o->klass(); | |
2883 oop mirror = Klass::cast(k)->java_mirror(); | |
2884 if (!CallbackInvoker::report_class_reference(o, mirror)) { | |
2885 return false; | |
2886 } | |
2887 | |
2888 // report the array contents if required | |
2889 if (is_reporting_primitive_array_values()) { | |
2890 if (!CallbackInvoker::report_primitive_array_values(o)) { | |
2891 return false; | |
2892 } | |
2893 } | |
2894 return true; | |
2895 } | |
2896 | |
2897 // verify that a static oop field is in range | |
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2898 static inline bool verify_static_oop(instanceKlass* ik, |
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2899 klassOop k, int offset) { |
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2900 address obj_p = (address)k + offset; |
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2901 address start = (address)ik->start_of_static_fields(); |
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2902 address end = start + (ik->static_oop_field_size() * heapOopSize); |
0 | 2903 assert(end >= start, "sanity check"); |
2904 | |
2905 if (obj_p >= start && obj_p < end) { | |
2906 return true; | |
2907 } else { | |
2908 return false; | |
2909 } | |
2910 } | |
2911 | |
2912 // a class references its super class, interfaces, class loader, ... | |
2913 // and finally its static fields | |
2914 inline bool VM_HeapWalkOperation::iterate_over_class(klassOop k) { | |
2915 int i; | |
2916 Klass* klass = klassOop(k)->klass_part(); | |
2917 | |
2918 if (klass->oop_is_instance()) { | |
2919 instanceKlass* ik = instanceKlass::cast(k); | |
2920 | |
2921 // ignore the class if it's has been initialized yet | |
2922 if (!ik->is_linked()) { | |
2923 return true; | |
2924 } | |
2925 | |
2926 // get the java mirror | |
2927 oop mirror = klass->java_mirror(); | |
2928 | |
2929 // super (only if something more interesting than java.lang.Object) | |
2930 klassOop java_super = ik->java_super(); | |
2931 if (java_super != NULL && java_super != SystemDictionary::object_klass()) { | |
2932 oop super = Klass::cast(java_super)->java_mirror(); | |
2933 if (!CallbackInvoker::report_superclass_reference(mirror, super)) { | |
2934 return false; | |
2935 } | |
2936 } | |
2937 | |
2938 // class loader | |
2939 oop cl = ik->class_loader(); | |
2940 if (cl != NULL) { | |
2941 if (!CallbackInvoker::report_class_loader_reference(mirror, cl)) { | |
2942 return false; | |
2943 } | |
2944 } | |
2945 | |
2946 // protection domain | |
2947 oop pd = ik->protection_domain(); | |
2948 if (pd != NULL) { | |
2949 if (!CallbackInvoker::report_protection_domain_reference(mirror, pd)) { | |
2950 return false; | |
2951 } | |
2952 } | |
2953 | |
2954 // signers | |
2955 oop signers = ik->signers(); | |
2956 if (signers != NULL) { | |
2957 if (!CallbackInvoker::report_signers_reference(mirror, signers)) { | |
2958 return false; | |
2959 } | |
2960 } | |
2961 | |
2962 // references from the constant pool | |
2963 { | |
2964 const constantPoolOop pool = ik->constants(); | |
2965 for (int i = 1; i < pool->length(); i++) { | |
2966 constantTag tag = pool->tag_at(i).value(); | |
2967 if (tag.is_string() || tag.is_klass()) { | |
2968 oop entry; | |
2969 if (tag.is_string()) { | |
2970 entry = pool->resolved_string_at(i); | |
2971 assert(java_lang_String::is_instance(entry), "must be string"); | |
2972 } else { | |
2973 entry = Klass::cast(pool->resolved_klass_at(i))->java_mirror(); | |
2974 } | |
2975 if (!CallbackInvoker::report_constant_pool_reference(mirror, entry, (jint)i)) { | |
2976 return false; | |
2977 } | |
2978 } | |
2979 } | |
2980 } | |
2981 | |
2982 // interfaces | |
2983 // (These will already have been reported as references from the constant pool | |
2984 // but are specified by IterateOverReachableObjects and must be reported). | |
2985 objArrayOop interfaces = ik->local_interfaces(); | |
2986 for (i = 0; i < interfaces->length(); i++) { | |
2987 oop interf = Klass::cast((klassOop)interfaces->obj_at(i))->java_mirror(); | |
2988 if (interf == NULL) { | |
2989 continue; | |
2990 } | |
2991 if (!CallbackInvoker::report_interface_reference(mirror, interf)) { | |
2992 return false; | |
2993 } | |
2994 } | |
2995 | |
2996 // iterate over the static fields | |
2997 | |
2998 ClassFieldMap* field_map = ClassFieldMap::create_map_of_static_fields(k); | |
2999 for (i=0; i<field_map->field_count(); i++) { | |
3000 ClassFieldDescriptor* field = field_map->field_at(i); | |
3001 char type = field->field_type(); | |
3002 if (!is_primitive_field_type(type)) { | |
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3003 oop fld_o = k->obj_field(field->field_offset()); |
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3004 assert(verify_static_oop(ik, k, field->field_offset()), "sanity check"); |
0 | 3005 if (fld_o != NULL) { |
3006 int slot = field->field_index(); | |
3007 if (!CallbackInvoker::report_static_field_reference(mirror, fld_o, slot)) { | |
3008 delete field_map; | |
3009 return false; | |
3010 } | |
3011 } | |
3012 } else { | |
3013 if (is_reporting_primitive_fields()) { | |
3014 address addr = (address)k + field->field_offset(); | |
3015 int slot = field->field_index(); | |
3016 if (!CallbackInvoker::report_primitive_static_field(mirror, slot, addr, type)) { | |
3017 delete field_map; | |
3018 return false; | |
3019 } | |
3020 } | |
3021 } | |
3022 } | |
3023 delete field_map; | |
3024 | |
3025 return true; | |
3026 } | |
3027 | |
3028 return true; | |
3029 } | |
3030 | |
3031 // an object references a class and its instance fields | |
3032 // (static fields are ignored here as we report these as | |
3033 // references from the class). | |
3034 inline bool VM_HeapWalkOperation::iterate_over_object(oop o) { | |
3035 // reference to the class | |
3036 if (!CallbackInvoker::report_class_reference(o, Klass::cast(o->klass())->java_mirror())) { | |
3037 return false; | |
3038 } | |
3039 | |
3040 // iterate over instance fields | |
3041 ClassFieldMap* field_map = JvmtiCachedClassFieldMap::get_map_of_instance_fields(o); | |
3042 for (int i=0; i<field_map->field_count(); i++) { | |
3043 ClassFieldDescriptor* field = field_map->field_at(i); | |
3044 char type = field->field_type(); | |
3045 if (!is_primitive_field_type(type)) { | |
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3046 oop fld_o = o->obj_field(field->field_offset()); |
0 | 3047 if (fld_o != NULL) { |
3048 // reflection code may have a reference to a klassOop. | |
3049 // - see sun.reflect.UnsafeStaticFieldAccessorImpl and sun.misc.Unsafe | |
3050 if (fld_o->is_klass()) { | |
3051 klassOop k = (klassOop)fld_o; | |
3052 fld_o = Klass::cast(k)->java_mirror(); | |
3053 } | |
3054 int slot = field->field_index(); | |
3055 if (!CallbackInvoker::report_field_reference(o, fld_o, slot)) { | |
3056 return false; | |
3057 } | |
3058 } | |
3059 } else { | |
3060 if (is_reporting_primitive_fields()) { | |
3061 // primitive instance field | |
3062 address addr = (address)o + field->field_offset(); | |
3063 int slot = field->field_index(); | |
3064 if (!CallbackInvoker::report_primitive_instance_field(o, slot, addr, type)) { | |
3065 return false; | |
3066 } | |
3067 } | |
3068 } | |
3069 } | |
3070 | |
3071 // if the object is a java.lang.String | |
3072 if (is_reporting_string_values() && | |
3073 o->klass() == SystemDictionary::string_klass()) { | |
3074 if (!CallbackInvoker::report_string_value(o)) { | |
3075 return false; | |
3076 } | |
3077 } | |
3078 return true; | |
3079 } | |
3080 | |
3081 | |
3082 // collects all simple (non-stack) roots. | |
3083 // if there's a heap root callback provided then the callback is | |
3084 // invoked for each simple root. | |
3085 // if an object reference callback is provided then all simple | |
3086 // roots are pushed onto the marking stack so that they can be | |
3087 // processed later | |
3088 // | |
3089 inline bool VM_HeapWalkOperation::collect_simple_roots() { | |
3090 SimpleRootsClosure blk; | |
3091 | |
3092 // JNI globals | |
3093 blk.set_kind(JVMTI_HEAP_REFERENCE_JNI_GLOBAL); | |
3094 JNIHandles::oops_do(&blk); | |
3095 if (blk.stopped()) { | |
3096 return false; | |
3097 } | |
3098 | |
3099 // Preloaded classes and loader from the system dictionary | |
3100 blk.set_kind(JVMTI_HEAP_REFERENCE_SYSTEM_CLASS); | |
3101 SystemDictionary::always_strong_oops_do(&blk); | |
3102 if (blk.stopped()) { | |
3103 return false; | |
3104 } | |
3105 | |
3106 // Inflated monitors | |
3107 blk.set_kind(JVMTI_HEAP_REFERENCE_MONITOR); | |
3108 ObjectSynchronizer::oops_do(&blk); | |
3109 if (blk.stopped()) { | |
3110 return false; | |
3111 } | |
3112 | |
3113 // Threads | |
3114 for (JavaThread* thread = Threads::first(); thread != NULL ; thread = thread->next()) { | |
3115 oop threadObj = thread->threadObj(); | |
3116 if (threadObj != NULL && !thread->is_exiting() && !thread->is_hidden_from_external_view()) { | |
3117 bool cont = CallbackInvoker::report_simple_root(JVMTI_HEAP_REFERENCE_THREAD, threadObj); | |
3118 if (!cont) { | |
3119 return false; | |
3120 } | |
3121 } | |
3122 } | |
3123 | |
3124 // Other kinds of roots maintained by HotSpot | |
3125 // Many of these won't be visible but others (such as instances of important | |
3126 // exceptions) will be visible. | |
3127 blk.set_kind(JVMTI_HEAP_REFERENCE_OTHER); | |
3128 Universe::oops_do(&blk); | |
3129 return true; | |
3130 } | |
3131 | |
3132 // Walk the stack of a given thread and find all references (locals | |
3133 // and JNI calls) and report these as stack references | |
3134 inline bool VM_HeapWalkOperation::collect_stack_roots(JavaThread* java_thread, | |
3135 JNILocalRootsClosure* blk) | |
3136 { | |
3137 oop threadObj = java_thread->threadObj(); | |
3138 assert(threadObj != NULL, "sanity check"); | |
3139 | |
3140 // only need to get the thread's tag once per thread | |
3141 jlong thread_tag = tag_for(_tag_map, threadObj); | |
3142 | |
3143 // also need the thread id | |
3144 jlong tid = java_lang_Thread::thread_id(threadObj); | |
3145 | |
3146 | |
3147 if (java_thread->has_last_Java_frame()) { | |
3148 | |
3149 // vframes are resource allocated | |
3150 Thread* current_thread = Thread::current(); | |
3151 ResourceMark rm(current_thread); | |
3152 HandleMark hm(current_thread); | |
3153 | |
3154 RegisterMap reg_map(java_thread); | |
3155 frame f = java_thread->last_frame(); | |
3156 vframe* vf = vframe::new_vframe(&f, ®_map, java_thread); | |
3157 | |
3158 bool is_top_frame = true; | |
3159 int depth = 0; | |
3160 frame* last_entry_frame = NULL; | |
3161 | |
3162 while (vf != NULL) { | |
3163 if (vf->is_java_frame()) { | |
3164 | |
3165 // java frame (interpreted, compiled, ...) | |
3166 javaVFrame *jvf = javaVFrame::cast(vf); | |
3167 | |
3168 // the jmethodID | |
3169 jmethodID method = jvf->method()->jmethod_id(); | |
3170 | |
3171 if (!(jvf->method()->is_native())) { | |
3172 jlocation bci = (jlocation)jvf->bci(); | |
3173 StackValueCollection* locals = jvf->locals(); | |
3174 for (int slot=0; slot<locals->size(); slot++) { | |
3175 if (locals->at(slot)->type() == T_OBJECT) { | |
3176 oop o = locals->obj_at(slot)(); | |
3177 if (o == NULL) { | |
3178 continue; | |
3179 } | |
3180 | |
3181 // stack reference | |
3182 if (!CallbackInvoker::report_stack_ref_root(thread_tag, tid, depth, method, | |
3183 bci, slot, o)) { | |
3184 return false; | |
3185 } | |
3186 } | |
3187 } | |
3188 } else { | |
3189 blk->set_context(thread_tag, tid, depth, method); | |
3190 if (is_top_frame) { | |
3191 // JNI locals for the top frame. | |
3192 java_thread->active_handles()->oops_do(blk); | |
3193 } else { | |
3194 if (last_entry_frame != NULL) { | |
3195 // JNI locals for the entry frame | |
3196 assert(last_entry_frame->is_entry_frame(), "checking"); | |
3197 last_entry_frame->entry_frame_call_wrapper()->handles()->oops_do(blk); | |
3198 } | |
3199 } | |
3200 } | |
3201 last_entry_frame = NULL; | |
3202 depth++; | |
3203 } else { | |
3204 // externalVFrame - for an entry frame then we report the JNI locals | |
3205 // when we find the corresponding javaVFrame | |
3206 frame* fr = vf->frame_pointer(); | |
3207 assert(fr != NULL, "sanity check"); | |
3208 if (fr->is_entry_frame()) { | |
3209 last_entry_frame = fr; | |
3210 } | |
3211 } | |
3212 | |
3213 vf = vf->sender(); | |
3214 is_top_frame = false; | |
3215 } | |
3216 } else { | |
3217 // no last java frame but there may be JNI locals | |
3218 blk->set_context(thread_tag, tid, 0, (jmethodID)NULL); | |
3219 java_thread->active_handles()->oops_do(blk); | |
3220 } | |
3221 return true; | |
3222 } | |
3223 | |
3224 | |
3225 // collects all stack roots - for each thread it walks the execution | |
3226 // stack to find all references and local JNI refs. | |
3227 inline bool VM_HeapWalkOperation::collect_stack_roots() { | |
3228 JNILocalRootsClosure blk; | |
3229 for (JavaThread* thread = Threads::first(); thread != NULL ; thread = thread->next()) { | |
3230 oop threadObj = thread->threadObj(); | |
3231 if (threadObj != NULL && !thread->is_exiting() && !thread->is_hidden_from_external_view()) { | |
3232 if (!collect_stack_roots(thread, &blk)) { | |
3233 return false; | |
3234 } | |
3235 } | |
3236 } | |
3237 return true; | |
3238 } | |
3239 | |
3240 // visit an object | |
3241 // first mark the object as visited | |
3242 // second get all the outbound references from this object (in other words, all | |
3243 // the objects referenced by this object). | |
3244 // | |
3245 bool VM_HeapWalkOperation::visit(oop o) { | |
3246 // mark object as visited | |
3247 assert(!ObjectMarker::visited(o), "can't visit same object more than once"); | |
3248 ObjectMarker::mark(o); | |
3249 | |
3250 // instance | |
3251 if (o->is_instance()) { | |
3252 if (o->klass() == SystemDictionary::class_klass()) { | |
3253 o = klassOop_if_java_lang_Class(o); | |
3254 if (o->is_klass()) { | |
3255 // a java.lang.Class | |
3256 return iterate_over_class(klassOop(o)); | |
3257 } | |
3258 } else { | |
3259 return iterate_over_object(o); | |
3260 } | |
3261 } | |
3262 | |
3263 // object array | |
3264 if (o->is_objArray()) { | |
3265 return iterate_over_array(o); | |
3266 } | |
3267 | |
3268 // type array | |
3269 if (o->is_typeArray()) { | |
3270 return iterate_over_type_array(o); | |
3271 } | |
3272 | |
3273 return true; | |
3274 } | |
3275 | |
3276 void VM_HeapWalkOperation::doit() { | |
3277 ResourceMark rm; | |
3278 ObjectMarkerController marker; | |
3279 ClassFieldMapCacheMark cm; | |
3280 | |
3281 assert(visit_stack()->is_empty(), "visit stack must be empty"); | |
3282 | |
3283 // the heap walk starts with an initial object or the heap roots | |
3284 if (initial_object().is_null()) { | |
3285 if (!collect_simple_roots()) return; | |
3286 if (!collect_stack_roots()) return; | |
3287 } else { | |
3288 visit_stack()->push(initial_object()()); | |
3289 } | |
3290 | |
3291 // object references required | |
3292 if (is_following_references()) { | |
3293 | |
3294 // visit each object until all reachable objects have been | |
3295 // visited or the callback asked to terminate the iteration. | |
3296 while (!visit_stack()->is_empty()) { | |
3297 oop o = visit_stack()->pop(); | |
3298 if (!ObjectMarker::visited(o)) { | |
3299 if (!visit(o)) { | |
3300 break; | |
3301 } | |
3302 } | |
3303 } | |
3304 } | |
3305 } | |
3306 | |
3307 // iterate over all objects that are reachable from a set of roots | |
3308 void JvmtiTagMap::iterate_over_reachable_objects(jvmtiHeapRootCallback heap_root_callback, | |
3309 jvmtiStackReferenceCallback stack_ref_callback, | |
3310 jvmtiObjectReferenceCallback object_ref_callback, | |
3311 const void* user_data) { | |
3312 MutexLocker ml(Heap_lock); | |
3313 BasicHeapWalkContext context(heap_root_callback, stack_ref_callback, object_ref_callback); | |
3314 VM_HeapWalkOperation op(this, Handle(), context, user_data); | |
3315 VMThread::execute(&op); | |
3316 } | |
3317 | |
3318 // iterate over all objects that are reachable from a given object | |
3319 void JvmtiTagMap::iterate_over_objects_reachable_from_object(jobject object, | |
3320 jvmtiObjectReferenceCallback object_ref_callback, | |
3321 const void* user_data) { | |
3322 oop obj = JNIHandles::resolve(object); | |
3323 Handle initial_object(Thread::current(), obj); | |
3324 | |
3325 MutexLocker ml(Heap_lock); | |
3326 BasicHeapWalkContext context(NULL, NULL, object_ref_callback); | |
3327 VM_HeapWalkOperation op(this, initial_object, context, user_data); | |
3328 VMThread::execute(&op); | |
3329 } | |
3330 | |
3331 // follow references from an initial object or the GC roots | |
3332 void JvmtiTagMap::follow_references(jint heap_filter, | |
3333 KlassHandle klass, | |
3334 jobject object, | |
3335 const jvmtiHeapCallbacks* callbacks, | |
3336 const void* user_data) | |
3337 { | |
3338 oop obj = JNIHandles::resolve(object); | |
3339 Handle initial_object(Thread::current(), obj); | |
3340 | |
3341 MutexLocker ml(Heap_lock); | |
3342 AdvancedHeapWalkContext context(heap_filter, klass, callbacks); | |
3343 VM_HeapWalkOperation op(this, initial_object, context, user_data); | |
3344 VMThread::execute(&op); | |
3345 } | |
3346 | |
3347 | |
3348 // called post-GC | |
3349 // - for each JVMTI environment with an object tag map, call its rehash | |
3350 // function to re-sync with the new object locations. | |
3351 void JvmtiTagMap::gc_epilogue(bool full) { | |
3352 assert(SafepointSynchronize::is_at_safepoint(), "must be executed at a safepoint"); | |
3353 if (JvmtiEnv::environments_might_exist()) { | |
3354 // re-obtain the memory region for the young generation (might | |
3355 // changed due to adaptive resizing policy) | |
3356 get_young_generation(); | |
3357 | |
3358 JvmtiEnvIterator it; | |
3359 for (JvmtiEnvBase* env = it.first(); env != NULL; env = it.next(env)) { | |
3360 JvmtiTagMap* tag_map = env->tag_map(); | |
3361 if (tag_map != NULL && !tag_map->is_empty()) { | |
3362 TraceTime t(full ? "JVMTI Full Rehash " : "JVMTI Rehash ", TraceJVMTIObjectTagging); | |
3363 if (full) { | |
3364 tag_map->rehash(0, n_hashmaps); | |
3365 } else { | |
3366 tag_map->rehash(0, 0); // tag map for young gen only | |
3367 } | |
3368 } | |
3369 } | |
3370 } | |
3371 } | |
3372 | |
3373 // CMS has completed referencing processing so we may have JNI weak refs | |
3374 // to objects in the CMS generation that have been GC'ed. | |
3375 void JvmtiTagMap::cms_ref_processing_epilogue() { | |
3376 assert(SafepointSynchronize::is_at_safepoint(), "must be executed at a safepoint"); | |
3377 assert(UseConcMarkSweepGC, "should only be used with CMS"); | |
3378 if (JvmtiEnv::environments_might_exist()) { | |
3379 JvmtiEnvIterator it; | |
3380 for (JvmtiEnvBase* env = it.first(); env != NULL; env = it.next(env)) { | |
3381 JvmtiTagMap* tag_map = ((JvmtiEnvBase *)env)->tag_map(); | |
3382 if (tag_map != NULL && !tag_map->is_empty()) { | |
3383 TraceTime t("JVMTI Rehash (CMS) ", TraceJVMTIObjectTagging); | |
3384 tag_map->rehash(1, n_hashmaps); // assume CMS not used in young gen | |
3385 } | |
3386 } | |
3387 } | |
3388 } | |
3389 | |
3390 | |
3391 // For each entry in the hashmaps 'start' to 'end' : | |
3392 // | |
3393 // 1. resolve the JNI weak reference | |
3394 // | |
3395 // 2. If it resolves to NULL it means the object has been freed so the entry | |
3396 // is removed, the weak reference destroyed, and the object free event is | |
3397 // posted (if enabled). | |
3398 // | |
3399 // 3. If the weak reference resolves to an object then we re-hash the object | |
3400 // to see if it has moved or has been promoted (from the young to the old | |
3401 // generation for example). | |
3402 // | |
3403 void JvmtiTagMap::rehash(int start, int end) { | |
3404 | |
3405 // does this environment have the OBJECT_FREE event enabled | |
3406 bool post_object_free = env()->is_enabled(JVMTI_EVENT_OBJECT_FREE); | |
3407 | |
3408 // counters used for trace message | |
3409 int freed = 0; | |
3410 int moved = 0; | |
3411 int promoted = 0; | |
3412 | |
3413 // we assume there are two hashmaps - one for the young generation | |
3414 // and the other for all other spaces. | |
3415 assert(n_hashmaps == 2, "not implemented"); | |
3416 JvmtiTagHashmap* young_hashmap = _hashmap[0]; | |
3417 JvmtiTagHashmap* other_hashmap = _hashmap[1]; | |
3418 | |
3419 // reenable sizing (if disabled) | |
3420 young_hashmap->set_resizing_enabled(true); | |
3421 other_hashmap->set_resizing_enabled(true); | |
3422 | |
3423 // when re-hashing the hashmap corresponding to the young generation we | |
3424 // collect the entries corresponding to objects that have been promoted. | |
3425 JvmtiTagHashmapEntry* promoted_entries = NULL; | |
3426 | |
3427 if (end >= n_hashmaps) { | |
3428 end = n_hashmaps - 1; | |
3429 } | |
3430 | |
3431 for (int i=start; i <= end; i++) { | |
3432 JvmtiTagHashmap* hashmap = _hashmap[i]; | |
3433 | |
3434 // if the hashmap is empty then we can skip it | |
3435 if (hashmap->_entry_count == 0) { | |
3436 continue; | |
3437 } | |
3438 | |
3439 // now iterate through each entry in the table | |
3440 | |
3441 JvmtiTagHashmapEntry** table = hashmap->table(); | |
3442 int size = hashmap->size(); | |
3443 | |
3444 for (int pos=0; pos<size; pos++) { | |
3445 JvmtiTagHashmapEntry* entry = table[pos]; | |
3446 JvmtiTagHashmapEntry* prev = NULL; | |
3447 | |
3448 while (entry != NULL) { | |
3449 JvmtiTagHashmapEntry* next = entry->next(); | |
3450 | |
3451 jweak ref = entry->object(); | |
3452 oop oop = JNIHandles::resolve(ref); | |
3453 | |
3454 // has object been GC'ed | |
3455 if (oop == NULL) { | |
3456 // grab the tag | |
3457 jlong tag = entry->tag(); | |
3458 guarantee(tag != 0, "checking"); | |
3459 | |
3460 // remove GC'ed entry from hashmap and return the | |
3461 // entry to the free list | |
3462 hashmap->remove(prev, pos, entry); | |
3463 destroy_entry(entry); | |
3464 | |
3465 // destroy the weak ref | |
3466 JNIHandles::destroy_weak_global(ref); | |
3467 | |
3468 // post the event to the profiler | |
3469 if (post_object_free) { | |
3470 JvmtiExport::post_object_free(env(), tag); | |
3471 } | |
3472 | |
3473 freed++; | |
3474 entry = next; | |
3475 continue; | |
3476 } | |
3477 | |
3478 // if this is the young hashmap then the object is either promoted | |
3479 // or moved. | |
3480 // if this is the other hashmap then the object is moved. | |
3481 | |
3482 bool same_gen; | |
3483 if (i == 0) { | |
3484 assert(hashmap == young_hashmap, "checking"); | |
3485 same_gen = is_in_young(oop); | |
3486 } else { | |
3487 same_gen = true; | |
3488 } | |
3489 | |
3490 | |
3491 if (same_gen) { | |
3492 // if the object has moved then re-hash it and move its | |
3493 // entry to its new location. | |
3494 unsigned int new_pos = JvmtiTagHashmap::hash(oop, size); | |
3495 if (new_pos != (unsigned int)pos) { | |
3496 if (prev == NULL) { | |
3497 table[pos] = next; | |
3498 } else { | |
3499 prev->set_next(next); | |
3500 } | |
3501 entry->set_next(table[new_pos]); | |
3502 table[new_pos] = entry; | |
3503 moved++; | |
3504 } else { | |
3505 // object didn't move | |
3506 prev = entry; | |
3507 } | |
3508 } else { | |
3509 // object has been promoted so remove the entry from the | |
3510 // young hashmap | |
3511 assert(hashmap == young_hashmap, "checking"); | |
3512 hashmap->remove(prev, pos, entry); | |
3513 | |
3514 // move the entry to the promoted list | |
3515 entry->set_next(promoted_entries); | |
3516 promoted_entries = entry; | |
3517 } | |
3518 | |
3519 entry = next; | |
3520 } | |
3521 } | |
3522 } | |
3523 | |
3524 | |
3525 // add the entries, corresponding to the promoted objects, to the | |
3526 // other hashmap. | |
3527 JvmtiTagHashmapEntry* entry = promoted_entries; | |
3528 while (entry != NULL) { | |
3529 oop o = JNIHandles::resolve(entry->object()); | |
3530 assert(hashmap_for(o) == other_hashmap, "checking"); | |
3531 JvmtiTagHashmapEntry* next = entry->next(); | |
3532 other_hashmap->add(o, entry); | |
3533 entry = next; | |
3534 promoted++; | |
3535 } | |
3536 | |
3537 // stats | |
3538 if (TraceJVMTIObjectTagging) { | |
3539 int total_moves = promoted + moved; | |
3540 | |
3541 int post_total = 0; | |
3542 for (int i=0; i<n_hashmaps; i++) { | |
3543 post_total += _hashmap[i]->_entry_count; | |
3544 } | |
3545 int pre_total = post_total + freed; | |
3546 | |
3547 tty->print("(%d->%d, %d freed, %d promoted, %d total moves)", | |
3548 pre_total, post_total, freed, promoted, total_moves); | |
3549 } | |
3550 } |