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src/share/vm/oops/instanceRefKlass.cpp@da91efe96a93
src/share/vm/oops/instanceRefKlass.cpp
Sat, 01 Sep 2012 13:25:18 -0400
- author
- coleenp
- date
- Sat, 01 Sep 2012 13:25:18 -0400
- changeset 4037
- da91efe96a93
- parent 3811
- c52a6a39546c
- child 4047
- aed758eda82a
- permissions
- -rw-r--r--
6964458: Reimplement class meta-data storage to use native memory
Summary: Remove PermGen, allocate meta-data in metaspace linked to class loaders, rewrite GC walking, rewrite and rename metadata to be C++ classes
Reviewed-by: jmasa, stefank, never, coleenp, kvn, brutisso, mgerdin, dholmes, jrose, twisti, roland
Contributed-by: jmasa <jon.masamitsu@oracle.com>, stefank <stefan.karlsson@oracle.com>, mgerdin <mikael.gerdin@oracle.com>, never <tom.rodriguez@oracle.com>
1 /*
2 * Copyright (c) 1997, 2012, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
25 #include "precompiled.hpp"
26 #include "classfile/javaClasses.hpp"
27 #include "classfile/systemDictionary.hpp"
28 #include "gc_implementation/shared/markSweep.inline.hpp"
29 #include "gc_interface/collectedHeap.hpp"
30 #include "gc_interface/collectedHeap.inline.hpp"
31 #include "memory/genCollectedHeap.hpp"
32 #include "memory/genOopClosures.inline.hpp"
33 #include "oops/instanceRefKlass.hpp"
34 #include "oops/oop.inline.hpp"
35 #include "utilities/preserveException.hpp"
36 #ifndef SERIALGC
37 #include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
38 #include "gc_implementation/g1/g1OopClosures.inline.hpp"
39 #include "gc_implementation/g1/g1RemSet.inline.hpp"
40 #include "gc_implementation/g1/heapRegionSeq.inline.hpp"
41 #include "gc_implementation/parNew/parOopClosures.inline.hpp"
42 #include "gc_implementation/parallelScavenge/psPromotionManager.inline.hpp"
43 #include "gc_implementation/parallelScavenge/psScavenge.inline.hpp"
44 #include "oops/oop.pcgc.inline.hpp"
45 #endif
47 template <class T>
48 void specialized_oop_follow_contents(instanceRefKlass* ref, oop obj) {
49 T* referent_addr = (T*)java_lang_ref_Reference::referent_addr(obj);
50 T heap_oop = oopDesc::load_heap_oop(referent_addr);
51 debug_only(
52 if(TraceReferenceGC && PrintGCDetails) {
53 gclog_or_tty->print_cr("instanceRefKlass::oop_follow_contents " INTPTR_FORMAT, obj);
54 }
55 )
56 if (!oopDesc::is_null(heap_oop)) {
57 oop referent = oopDesc::decode_heap_oop_not_null(heap_oop);
58 if (!referent->is_gc_marked() &&
59 MarkSweep::ref_processor()->discover_reference(obj, ref->reference_type())) {
60 // reference was discovered, referent will be traversed later
61 ref->InstanceKlass::oop_follow_contents(obj);
62 debug_only(
63 if(TraceReferenceGC && PrintGCDetails) {
64 gclog_or_tty->print_cr(" Non NULL enqueued " INTPTR_FORMAT, obj);
65 }
66 )
67 return;
68 } else {
69 // treat referent as normal oop
70 debug_only(
71 if(TraceReferenceGC && PrintGCDetails) {
72 gclog_or_tty->print_cr(" Non NULL normal " INTPTR_FORMAT, obj);
73 }
74 )
75 MarkSweep::mark_and_push(referent_addr);
76 }
77 }
78 T* next_addr = (T*)java_lang_ref_Reference::next_addr(obj);
79 if (ReferenceProcessor::pending_list_uses_discovered_field()) {
80 // Treat discovered as normal oop, if ref is not "active",
81 // i.e. if next is non-NULL.
82 T next_oop = oopDesc::load_heap_oop(next_addr);
83 if (!oopDesc::is_null(next_oop)) { // i.e. ref is not "active"
84 T* discovered_addr = (T*)java_lang_ref_Reference::discovered_addr(obj);
85 debug_only(
86 if(TraceReferenceGC && PrintGCDetails) {
87 gclog_or_tty->print_cr(" Process discovered as normal "
88 INTPTR_FORMAT, discovered_addr);
89 }
90 )
91 MarkSweep::mark_and_push(discovered_addr);
92 }
93 } else {
94 #ifdef ASSERT
95 // In the case of older JDKs which do not use the discovered
96 // field for the pending list, an inactive ref (next != NULL)
97 // must always have a NULL discovered field.
98 oop next = oopDesc::load_decode_heap_oop(next_addr);
99 oop discovered = java_lang_ref_Reference::discovered(obj);
100 assert(oopDesc::is_null(next) || oopDesc::is_null(discovered),
101 err_msg("Found an inactive reference " PTR_FORMAT " with a non-NULL discovered field",
102 (oopDesc*)obj));
103 #endif
104 }
105 // treat next as normal oop. next is a link in the reference queue.
106 debug_only(
107 if(TraceReferenceGC && PrintGCDetails) {
108 gclog_or_tty->print_cr(" Process next as normal " INTPTR_FORMAT, next_addr);
109 }
110 )
111 MarkSweep::mark_and_push(next_addr);
112 ref->InstanceKlass::oop_follow_contents(obj);
113 }
115 void instanceRefKlass::oop_follow_contents(oop obj) {
116 if (UseCompressedOops) {
117 specialized_oop_follow_contents<narrowOop>(this, obj);
118 } else {
119 specialized_oop_follow_contents<oop>(this, obj);
120 }
121 }
123 #ifndef SERIALGC
124 template <class T>
125 void specialized_oop_follow_contents(instanceRefKlass* ref,
126 ParCompactionManager* cm,
127 oop obj) {
128 T* referent_addr = (T*)java_lang_ref_Reference::referent_addr(obj);
129 T heap_oop = oopDesc::load_heap_oop(referent_addr);
130 debug_only(
131 if(TraceReferenceGC && PrintGCDetails) {
132 gclog_or_tty->print_cr("instanceRefKlass::oop_follow_contents " INTPTR_FORMAT, obj);
133 }
134 )
135 if (!oopDesc::is_null(heap_oop)) {
136 oop referent = oopDesc::decode_heap_oop_not_null(heap_oop);
137 if (PSParallelCompact::mark_bitmap()->is_unmarked(referent) &&
138 PSParallelCompact::ref_processor()->
139 discover_reference(obj, ref->reference_type())) {
140 // reference already enqueued, referent will be traversed later
141 ref->InstanceKlass::oop_follow_contents(cm, obj);
142 debug_only(
143 if(TraceReferenceGC && PrintGCDetails) {
144 gclog_or_tty->print_cr(" Non NULL enqueued " INTPTR_FORMAT, obj);
145 }
146 )
147 return;
148 } else {
149 // treat referent as normal oop
150 debug_only(
151 if(TraceReferenceGC && PrintGCDetails) {
152 gclog_or_tty->print_cr(" Non NULL normal " INTPTR_FORMAT, obj);
153 }
154 )
155 PSParallelCompact::mark_and_push(cm, referent_addr);
156 }
157 }
158 T* next_addr = (T*)java_lang_ref_Reference::next_addr(obj);
159 if (ReferenceProcessor::pending_list_uses_discovered_field()) {
160 // Treat discovered as normal oop, if ref is not "active",
161 // i.e. if next is non-NULL.
162 T next_oop = oopDesc::load_heap_oop(next_addr);
163 if (!oopDesc::is_null(next_oop)) { // i.e. ref is not "active"
164 T* discovered_addr = (T*)java_lang_ref_Reference::discovered_addr(obj);
165 debug_only(
166 if(TraceReferenceGC && PrintGCDetails) {
167 gclog_or_tty->print_cr(" Process discovered as normal "
168 INTPTR_FORMAT, discovered_addr);
169 }
170 )
171 PSParallelCompact::mark_and_push(cm, discovered_addr);
172 }
173 } else {
174 #ifdef ASSERT
175 // In the case of older JDKs which do not use the discovered
176 // field for the pending list, an inactive ref (next != NULL)
177 // must always have a NULL discovered field.
178 T next = oopDesc::load_heap_oop(next_addr);
179 oop discovered = java_lang_ref_Reference::discovered(obj);
180 assert(oopDesc::is_null(next) || oopDesc::is_null(discovered),
181 err_msg("Found an inactive reference " PTR_FORMAT " with a non-NULL discovered field",
182 (oopDesc*)obj));
183 #endif
184 }
185 PSParallelCompact::mark_and_push(cm, next_addr);
186 ref->InstanceKlass::oop_follow_contents(cm, obj);
187 }
189 void instanceRefKlass::oop_follow_contents(ParCompactionManager* cm,
190 oop obj) {
191 if (UseCompressedOops) {
192 specialized_oop_follow_contents<narrowOop>(this, cm, obj);
193 } else {
194 specialized_oop_follow_contents<oop>(this, cm, obj);
195 }
196 }
197 #endif // SERIALGC
199 #ifdef ASSERT
200 template <class T> void trace_reference_gc(const char *s, oop obj,
201 T* referent_addr,
202 T* next_addr,
203 T* discovered_addr) {
204 if(TraceReferenceGC && PrintGCDetails) {
205 gclog_or_tty->print_cr("%s obj " INTPTR_FORMAT, s, (address)obj);
206 gclog_or_tty->print_cr(" referent_addr/* " INTPTR_FORMAT " / "
207 INTPTR_FORMAT, referent_addr,
208 referent_addr ?
209 (address)oopDesc::load_decode_heap_oop(referent_addr) : NULL);
210 gclog_or_tty->print_cr(" next_addr/* " INTPTR_FORMAT " / "
211 INTPTR_FORMAT, next_addr,
212 next_addr ? (address)oopDesc::load_decode_heap_oop(next_addr) : NULL);
213 gclog_or_tty->print_cr(" discovered_addr/* " INTPTR_FORMAT " / "
214 INTPTR_FORMAT, discovered_addr,
215 discovered_addr ?
216 (address)oopDesc::load_decode_heap_oop(discovered_addr) : NULL);
217 }
218 }
219 #endif
221 template <class T> void specialized_oop_adjust_pointers(instanceRefKlass *ref, oop obj) {
222 T* referent_addr = (T*)java_lang_ref_Reference::referent_addr(obj);
223 MarkSweep::adjust_pointer(referent_addr);
224 T* next_addr = (T*)java_lang_ref_Reference::next_addr(obj);
225 MarkSweep::adjust_pointer(next_addr);
226 T* discovered_addr = (T*)java_lang_ref_Reference::discovered_addr(obj);
227 MarkSweep::adjust_pointer(discovered_addr);
228 debug_only(trace_reference_gc("instanceRefKlass::oop_adjust_pointers", obj,
229 referent_addr, next_addr, discovered_addr);)
230 }
232 int instanceRefKlass::oop_adjust_pointers(oop obj) {
233 int size = size_helper();
234 InstanceKlass::oop_adjust_pointers(obj);
236 if (UseCompressedOops) {
237 specialized_oop_adjust_pointers<narrowOop>(this, obj);
238 } else {
239 specialized_oop_adjust_pointers<oop>(this, obj);
240 }
241 return size;
242 }
244 #define InstanceRefKlass_SPECIALIZED_OOP_ITERATE(T, nv_suffix, contains) \
245 T* disc_addr = (T*)java_lang_ref_Reference::discovered_addr(obj); \
246 if (closure->apply_to_weak_ref_discovered_field()) { \
247 closure->do_oop##nv_suffix(disc_addr); \
248 } \
249 \
250 T* referent_addr = (T*)java_lang_ref_Reference::referent_addr(obj); \
251 T heap_oop = oopDesc::load_heap_oop(referent_addr); \
252 ReferenceProcessor* rp = closure->_ref_processor; \
253 if (!oopDesc::is_null(heap_oop)) { \
254 oop referent = oopDesc::decode_heap_oop_not_null(heap_oop); \
255 if (!referent->is_gc_marked() && (rp != NULL) && \
256 rp->discover_reference(obj, reference_type())) { \
257 return size; \
258 } else if (contains(referent_addr)) { \
259 /* treat referent as normal oop */ \
260 SpecializationStats::record_do_oop_call##nv_suffix(SpecializationStats::irk);\
261 closure->do_oop##nv_suffix(referent_addr); \
262 } \
263 } \
264 T* next_addr = (T*)java_lang_ref_Reference::next_addr(obj); \
265 if (ReferenceProcessor::pending_list_uses_discovered_field()) { \
266 T next_oop = oopDesc::load_heap_oop(next_addr); \
267 /* Treat discovered as normal oop, if ref is not "active" (next non-NULL) */\
268 if (!oopDesc::is_null(next_oop) && contains(disc_addr)) { \
269 /* i.e. ref is not "active" */ \
270 debug_only( \
271 if(TraceReferenceGC && PrintGCDetails) { \
272 gclog_or_tty->print_cr(" Process discovered as normal " \
273 INTPTR_FORMAT, disc_addr); \
274 } \
275 ) \
276 SpecializationStats::record_do_oop_call##nv_suffix(SpecializationStats::irk);\
277 closure->do_oop##nv_suffix(disc_addr); \
278 } \
279 } else { \
280 /* In the case of older JDKs which do not use the discovered field for */ \
281 /* the pending list, an inactive ref (next != NULL) must always have a */ \
282 /* NULL discovered field. */ \
283 debug_only( \
284 T next_oop = oopDesc::load_heap_oop(next_addr); \
285 T disc_oop = oopDesc::load_heap_oop(disc_addr); \
286 assert(oopDesc::is_null(next_oop) || oopDesc::is_null(disc_oop), \
287 err_msg("Found an inactive reference " PTR_FORMAT " with a non-NULL" \
288 "discovered field", (oopDesc*)obj)); \
289 ) \
290 } \
291 /* treat next as normal oop */ \
292 if (contains(next_addr)) { \
293 SpecializationStats::record_do_oop_call##nv_suffix(SpecializationStats::irk); \
294 closure->do_oop##nv_suffix(next_addr); \
295 } \
296 return size; \
299 template <class T> bool contains(T *t) { return true; }
301 // Macro to define instanceRefKlass::oop_oop_iterate for virtual/nonvirtual for
302 // all closures. Macros calling macros above for each oop size.
304 #define InstanceRefKlass_OOP_OOP_ITERATE_DEFN(OopClosureType, nv_suffix) \
305 \
306 int instanceRefKlass:: \
307 oop_oop_iterate##nv_suffix(oop obj, OopClosureType* closure) { \
308 /* Get size before changing pointers */ \
309 SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::irk);\
310 \
311 int size = InstanceKlass::oop_oop_iterate##nv_suffix(obj, closure); \
312 \
313 if (UseCompressedOops) { \
314 InstanceRefKlass_SPECIALIZED_OOP_ITERATE(narrowOop, nv_suffix, contains); \
315 } else { \
316 InstanceRefKlass_SPECIALIZED_OOP_ITERATE(oop, nv_suffix, contains); \
317 } \
318 }
320 #ifndef SERIALGC
321 #define InstanceRefKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN(OopClosureType, nv_suffix) \
322 \
323 int instanceRefKlass:: \
324 oop_oop_iterate_backwards##nv_suffix(oop obj, OopClosureType* closure) { \
325 /* Get size before changing pointers */ \
326 SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::irk);\
327 \
328 int size = InstanceKlass::oop_oop_iterate_backwards##nv_suffix(obj, closure); \
329 \
330 if (UseCompressedOops) { \
331 InstanceRefKlass_SPECIALIZED_OOP_ITERATE(narrowOop, nv_suffix, contains); \
332 } else { \
333 InstanceRefKlass_SPECIALIZED_OOP_ITERATE(oop, nv_suffix, contains); \
334 } \
335 }
336 #endif // !SERIALGC
339 #define InstanceRefKlass_OOP_OOP_ITERATE_DEFN_m(OopClosureType, nv_suffix) \
340 \
341 int instanceRefKlass:: \
342 oop_oop_iterate##nv_suffix##_m(oop obj, \
343 OopClosureType* closure, \
344 MemRegion mr) { \
345 SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::irk);\
346 \
347 int size = InstanceKlass::oop_oop_iterate##nv_suffix##_m(obj, closure, mr); \
348 if (UseCompressedOops) { \
349 InstanceRefKlass_SPECIALIZED_OOP_ITERATE(narrowOop, nv_suffix, mr.contains); \
350 } else { \
351 InstanceRefKlass_SPECIALIZED_OOP_ITERATE(oop, nv_suffix, mr.contains); \
352 } \
353 }
355 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceRefKlass_OOP_OOP_ITERATE_DEFN)
356 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceRefKlass_OOP_OOP_ITERATE_DEFN)
357 #ifndef SERIALGC
358 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceRefKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN)
359 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceRefKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN)
360 #endif // SERIALGC
361 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceRefKlass_OOP_OOP_ITERATE_DEFN_m)
362 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceRefKlass_OOP_OOP_ITERATE_DEFN_m)
364 #ifndef SERIALGC
365 template <class T>
366 void specialized_oop_push_contents(instanceRefKlass *ref,
367 PSPromotionManager* pm, oop obj) {
368 T* referent_addr = (T*)java_lang_ref_Reference::referent_addr(obj);
369 if (PSScavenge::should_scavenge(referent_addr)) {
370 ReferenceProcessor* rp = PSScavenge::reference_processor();
371 if (rp->discover_reference(obj, ref->reference_type())) {
372 // reference already enqueued, referent and next will be traversed later
373 ref->InstanceKlass::oop_push_contents(pm, obj);
374 return;
375 } else {
376 // treat referent as normal oop
377 pm->claim_or_forward_depth(referent_addr);
378 }
379 }
380 // Treat discovered as normal oop, if ref is not "active",
381 // i.e. if next is non-NULL.
382 T* next_addr = (T*)java_lang_ref_Reference::next_addr(obj);
383 if (ReferenceProcessor::pending_list_uses_discovered_field()) {
384 T next_oop = oopDesc::load_heap_oop(next_addr);
385 if (!oopDesc::is_null(next_oop)) { // i.e. ref is not "active"
386 T* discovered_addr = (T*)java_lang_ref_Reference::discovered_addr(obj);
387 debug_only(
388 if(TraceReferenceGC && PrintGCDetails) {
389 gclog_or_tty->print_cr(" Process discovered as normal "
390 INTPTR_FORMAT, discovered_addr);
391 }
392 )
393 if (PSScavenge::should_scavenge(discovered_addr)) {
394 pm->claim_or_forward_depth(discovered_addr);
395 }
396 }
397 } else {
398 #ifdef ASSERT
399 // In the case of older JDKs which do not use the discovered
400 // field for the pending list, an inactive ref (next != NULL)
401 // must always have a NULL discovered field.
402 oop next = oopDesc::load_decode_heap_oop(next_addr);
403 oop discovered = java_lang_ref_Reference::discovered(obj);
404 assert(oopDesc::is_null(next) || oopDesc::is_null(discovered),
405 err_msg("Found an inactive reference " PTR_FORMAT " with a non-NULL discovered field",
406 (oopDesc*)obj));
407 #endif
408 }
410 // Treat next as normal oop; next is a link in the reference queue.
411 if (PSScavenge::should_scavenge(next_addr)) {
412 pm->claim_or_forward_depth(next_addr);
413 }
414 ref->InstanceKlass::oop_push_contents(pm, obj);
415 }
417 void instanceRefKlass::oop_push_contents(PSPromotionManager* pm, oop obj) {
418 if (UseCompressedOops) {
419 specialized_oop_push_contents<narrowOop>(this, pm, obj);
420 } else {
421 specialized_oop_push_contents<oop>(this, pm, obj);
422 }
423 }
425 template <class T>
426 void specialized_oop_update_pointers(instanceRefKlass *ref,
427 ParCompactionManager* cm, oop obj) {
428 T* referent_addr = (T*)java_lang_ref_Reference::referent_addr(obj);
429 PSParallelCompact::adjust_pointer(referent_addr);
430 T* next_addr = (T*)java_lang_ref_Reference::next_addr(obj);
431 PSParallelCompact::adjust_pointer(next_addr);
432 T* discovered_addr = (T*)java_lang_ref_Reference::discovered_addr(obj);
433 PSParallelCompact::adjust_pointer(discovered_addr);
434 debug_only(trace_reference_gc("instanceRefKlass::oop_update_ptrs", obj,
435 referent_addr, next_addr, discovered_addr);)
436 }
438 int instanceRefKlass::oop_update_pointers(ParCompactionManager* cm, oop obj) {
439 InstanceKlass::oop_update_pointers(cm, obj);
440 if (UseCompressedOops) {
441 specialized_oop_update_pointers<narrowOop>(this, cm, obj);
442 } else {
443 specialized_oop_update_pointers<oop>(this, cm, obj);
444 }
445 return size_helper();
446 }
447 #endif // SERIALGC
449 void instanceRefKlass::update_nonstatic_oop_maps(Klass* k) {
450 // Clear the nonstatic oop-map entries corresponding to referent
451 // and nextPending field. They are treated specially by the
452 // garbage collector.
453 // The discovered field is used only by the garbage collector
454 // and is also treated specially.
455 InstanceKlass* ik = InstanceKlass::cast(k);
457 // Check that we have the right class
458 debug_only(static bool first_time = true);
459 assert(k == SystemDictionary::Reference_klass() && first_time,
460 "Invalid update of maps");
461 debug_only(first_time = false);
462 assert(ik->nonstatic_oop_map_count() == 1, "just checking");
464 OopMapBlock* map = ik->start_of_nonstatic_oop_maps();
466 // Check that the current map is (2,4) - currently points at field with
467 // offset 2 (words) and has 4 map entries.
468 debug_only(int offset = java_lang_ref_Reference::referent_offset);
469 debug_only(unsigned int count = ((java_lang_ref_Reference::discovered_offset -
470 java_lang_ref_Reference::referent_offset)/heapOopSize) + 1);
472 if (UseSharedSpaces) {
473 assert(map->offset() == java_lang_ref_Reference::queue_offset &&
474 map->count() == 1, "just checking");
475 } else {
476 assert(map->offset() == offset && map->count() == count,
477 "just checking");
479 // Update map to (3,1) - point to offset of 3 (words) with 1 map entry.
480 map->set_offset(java_lang_ref_Reference::queue_offset);
481 map->set_count(1);
482 }
483 }
486 // Verification
488 void instanceRefKlass::oop_verify_on(oop obj, outputStream* st) {
489 InstanceKlass::oop_verify_on(obj, st);
490 // Verify referent field
491 oop referent = java_lang_ref_Reference::referent(obj);
493 // We should make this general to all heaps
494 GenCollectedHeap* gch = NULL;
495 if (Universe::heap()->kind() == CollectedHeap::GenCollectedHeap)
496 gch = GenCollectedHeap::heap();
498 if (referent != NULL) {
499 guarantee(referent->is_oop(), "referent field heap failed");
500 }
501 // Verify next field
502 oop next = java_lang_ref_Reference::next(obj);
503 if (next != NULL) {
504 guarantee(next->is_oop(), "next field verify failed");
505 guarantee(next->is_instanceRef(), "next field verify failed");
506 }
507 }
509 bool instanceRefKlass::owns_pending_list_lock(JavaThread* thread) {
510 if (java_lang_ref_Reference::pending_list_lock() == NULL) return false;
511 Handle h_lock(thread, java_lang_ref_Reference::pending_list_lock());
512 return ObjectSynchronizer::current_thread_holds_lock(thread, h_lock);
513 }
515 void instanceRefKlass::acquire_pending_list_lock(BasicLock *pending_list_basic_lock) {
516 // we may enter this with pending exception set
517 PRESERVE_EXCEPTION_MARK; // exceptions are never thrown, needed for TRAPS argument
519 // Create a HandleMark in case we retry a GC multiple times.
520 // Each time we attempt the GC, we allocate the handle below
521 // to hold the pending list lock. We want to free this handle.
522 HandleMark hm;
524 Handle h_lock(THREAD, java_lang_ref_Reference::pending_list_lock());
525 ObjectSynchronizer::fast_enter(h_lock, pending_list_basic_lock, false, THREAD);
526 assert(ObjectSynchronizer::current_thread_holds_lock(
527 JavaThread::current(), h_lock),
528 "Locking should have succeeded");
529 if (HAS_PENDING_EXCEPTION) CLEAR_PENDING_EXCEPTION;
530 }
532 void instanceRefKlass::release_and_notify_pending_list_lock(
533 BasicLock *pending_list_basic_lock) {
534 // we may enter this with pending exception set
535 PRESERVE_EXCEPTION_MARK; // exceptions are never thrown, needed for TRAPS argument
537 // Create a HandleMark in case we retry a GC multiple times.
538 // Each time we attempt the GC, we allocate the handle below
539 // to hold the pending list lock. We want to free this handle.
540 HandleMark hm;
542 Handle h_lock(THREAD, java_lang_ref_Reference::pending_list_lock());
543 assert(ObjectSynchronizer::current_thread_holds_lock(
544 JavaThread::current(), h_lock),
545 "Lock should be held");
546 // Notify waiters on pending lists lock if there is any reference.
547 if (java_lang_ref_Reference::pending_list() != NULL) {
548 ObjectSynchronizer::notifyall(h_lock, THREAD);
549 }
550 ObjectSynchronizer::fast_exit(h_lock(), pending_list_basic_lock, THREAD);
551 if (HAS_PENDING_EXCEPTION) CLEAR_PENDING_EXCEPTION;
552 }
