1 /*
2 * Copyright (c) 2001, 2018, 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 */
24
25 #include "precompiled.hpp"
26 #include "classfile/systemDictionary.hpp"
27 #include "gc/shared/allocTracer.hpp"
28 #include "gc/shared/barrierSet.hpp"
29 #include "gc/shared/collectedHeap.hpp"
30 #include "gc/shared/collectedHeap.inline.hpp"
31 #include "gc/shared/gcLocker.inline.hpp"
32 #include "gc/shared/gcHeapSummary.hpp"
33 #include "gc/shared/gcTrace.hpp"
34 #include "gc/shared/gcTraceTime.inline.hpp"
35 #include "gc/shared/gcWhen.hpp"
36 #include "gc/shared/vmGCOperations.hpp"
37 #include "logging/log.hpp"
38 #include "memory/metaspace.hpp"
39 #include "memory/resourceArea.hpp"
40 #include "oops/instanceMirrorKlass.hpp"
41 #include "oops/oop.inline.hpp"
42 #include "runtime/handles.inline.hpp"
43 #include "runtime/init.hpp"
44 #include "runtime/thread.inline.hpp"
45 #include "runtime/threadSMR.hpp"
46 #include "runtime/vmThread.hpp"
47 #include "services/heapDumper.hpp"
48 #include "utilities/align.hpp"
49
50 class ClassLoaderData;
51
52 #ifdef ASSERT
53 int CollectedHeap::_fire_out_of_memory_count = 0;
54 #endif
55
56 size_t CollectedHeap::_filler_array_max_size = 0;
57
58 template <>
59 void EventLogBase<GCMessage>::print(outputStream* st, GCMessage& m) {
60 st->print_cr("GC heap %s", m.is_before ? "before" : "after");
61 st->print_raw(m);
62 }
63
64 void GCHeapLog::log_heap(CollectedHeap* heap, bool before) {
65 if (!should_log()) {
66 return;
67 }
68
69 double timestamp = fetch_timestamp();
70 MutexLockerEx ml(&_mutex, Mutex::_no_safepoint_check_flag);
71 int index = compute_log_index();
72 _records[index].thread = NULL; // Its the GC thread so it's not that interesting.
73 _records[index].timestamp = timestamp;
74 _records[index].data.is_before = before;
75 stringStream st(_records[index].data.buffer(), _records[index].data.size());
76
77 st.print_cr("{Heap %s GC invocations=%u (full %u):",
78 before ? "before" : "after",
79 heap->total_collections(),
80 heap->total_full_collections());
81
82 heap->print_on(&st);
83 st.print_cr("}");
84 }
85
86 VirtualSpaceSummary CollectedHeap::create_heap_space_summary() {
87 size_t capacity_in_words = capacity() / HeapWordSize;
88
89 return VirtualSpaceSummary(
90 reserved_region().start(), reserved_region().start() + capacity_in_words, reserved_region().end());
91 }
92
93 GCHeapSummary CollectedHeap::create_heap_summary() {
94 VirtualSpaceSummary heap_space = create_heap_space_summary();
95 return GCHeapSummary(heap_space, used());
96 }
97
98 MetaspaceSummary CollectedHeap::create_metaspace_summary() {
99 const MetaspaceSizes meta_space(
100 MetaspaceUtils::committed_bytes(),
101 MetaspaceUtils::used_bytes(),
102 MetaspaceUtils::reserved_bytes());
103 const MetaspaceSizes data_space(
104 MetaspaceUtils::committed_bytes(Metaspace::NonClassType),
105 MetaspaceUtils::used_bytes(Metaspace::NonClassType),
106 MetaspaceUtils::reserved_bytes(Metaspace::NonClassType));
107 const MetaspaceSizes class_space(
108 MetaspaceUtils::committed_bytes(Metaspace::ClassType),
109 MetaspaceUtils::used_bytes(Metaspace::ClassType),
110 MetaspaceUtils::reserved_bytes(Metaspace::ClassType));
111
112 const MetaspaceChunkFreeListSummary& ms_chunk_free_list_summary =
113 MetaspaceUtils::chunk_free_list_summary(Metaspace::NonClassType);
114 const MetaspaceChunkFreeListSummary& class_chunk_free_list_summary =
115 MetaspaceUtils::chunk_free_list_summary(Metaspace::ClassType);
116
117 return MetaspaceSummary(MetaspaceGC::capacity_until_GC(), meta_space, data_space, class_space,
118 ms_chunk_free_list_summary, class_chunk_free_list_summary);
119 }
120
121 void CollectedHeap::print_heap_before_gc() {
122 Universe::print_heap_before_gc();
123 if (_gc_heap_log != NULL) {
124 _gc_heap_log->log_heap_before(this);
125 }
126 }
127
128 void CollectedHeap::print_heap_after_gc() {
129 Universe::print_heap_after_gc();
130 if (_gc_heap_log != NULL) {
131 _gc_heap_log->log_heap_after(this);
132 }
133 }
134
135 void CollectedHeap::print_on_error(outputStream* st) const {
136 st->print_cr("Heap:");
137 print_extended_on(st);
138 st->cr();
139
140 BarrierSet::barrier_set()->print_on(st);
141 }
142
143 void CollectedHeap::trace_heap(GCWhen::Type when, const GCTracer* gc_tracer) {
144 const GCHeapSummary& heap_summary = create_heap_summary();
145 gc_tracer->report_gc_heap_summary(when, heap_summary);
146
147 const MetaspaceSummary& metaspace_summary = create_metaspace_summary();
148 gc_tracer->report_metaspace_summary(when, metaspace_summary);
149 }
150
151 void CollectedHeap::trace_heap_before_gc(const GCTracer* gc_tracer) {
152 trace_heap(GCWhen::BeforeGC, gc_tracer);
153 }
154
155 void CollectedHeap::trace_heap_after_gc(const GCTracer* gc_tracer) {
156 trace_heap(GCWhen::AfterGC, gc_tracer);
157 }
158
159 // WhiteBox API support for concurrent collectors. These are the
160 // default implementations, for collectors which don't support this
161 // feature.
162 bool CollectedHeap::supports_concurrent_phase_control() const {
163 return false;
164 }
165
166 const char* const* CollectedHeap::concurrent_phases() const {
167 static const char* const result[] = { NULL };
168 return result;
169 }
170
171 bool CollectedHeap::request_concurrent_phase(const char* phase) {
172 return false;
173 }
174
175 // Memory state functions.
176
177
178 CollectedHeap::CollectedHeap() :
179 _is_gc_active(false),
180 _total_collections(0),
181 _total_full_collections(0),
182 _gc_cause(GCCause::_no_gc),
183 _gc_lastcause(GCCause::_no_gc)
184 {
185 const size_t max_len = size_t(arrayOopDesc::max_array_length(T_INT));
186 const size_t elements_per_word = HeapWordSize / sizeof(jint);
187 _filler_array_max_size = align_object_size(filler_array_hdr_size() +
188 max_len / elements_per_word);
189
190 NOT_PRODUCT(_promotion_failure_alot_count = 0;)
191 NOT_PRODUCT(_promotion_failure_alot_gc_number = 0;)
192
193 if (UsePerfData) {
194 EXCEPTION_MARK;
195
196 // create the gc cause jvmstat counters
197 _perf_gc_cause = PerfDataManager::create_string_variable(SUN_GC, "cause",
198 80, GCCause::to_string(_gc_cause), CHECK);
199
200 _perf_gc_lastcause =
201 PerfDataManager::create_string_variable(SUN_GC, "lastCause",
202 80, GCCause::to_string(_gc_lastcause), CHECK);
203 }
204
205 // Create the ring log
206 if (LogEvents) {
207 _gc_heap_log = new GCHeapLog();
208 } else {
209 _gc_heap_log = NULL;
210 }
211 }
212
213 // This interface assumes that it's being called by the
214 // vm thread. It collects the heap assuming that the
215 // heap lock is already held and that we are executing in
216 // the context of the vm thread.
217 void CollectedHeap::collect_as_vm_thread(GCCause::Cause cause) {
218 assert(Thread::current()->is_VM_thread(), "Precondition#1");
219 assert(Heap_lock->is_locked(), "Precondition#2");
220 GCCauseSetter gcs(this, cause);
221 switch (cause) {
222 case GCCause::_heap_inspection:
223 case GCCause::_heap_dump:
224 case GCCause::_metadata_GC_threshold : {
225 HandleMark hm;
226 do_full_collection(false); // don't clear all soft refs
227 break;
228 }
229 case GCCause::_metadata_GC_clear_soft_refs: {
230 HandleMark hm;
231 do_full_collection(true); // do clear all soft refs
232 break;
233 }
234 default:
235 ShouldNotReachHere(); // Unexpected use of this function
236 }
237 }
238
239 MetaWord* CollectedHeap::satisfy_failed_metadata_allocation(ClassLoaderData* loader_data,
240 size_t word_size,
241 Metaspace::MetadataType mdtype) {
242 uint loop_count = 0;
243 uint gc_count = 0;
244 uint full_gc_count = 0;
245
246 assert(!Heap_lock->owned_by_self(), "Should not be holding the Heap_lock");
247
248 do {
249 MetaWord* result = loader_data->metaspace_non_null()->allocate(word_size, mdtype);
250 if (result != NULL) {
251 return result;
252 }
253
254 if (GCLocker::is_active_and_needs_gc()) {
255 // If the GCLocker is active, just expand and allocate.
256 // If that does not succeed, wait if this thread is not
257 // in a critical section itself.
258 result = loader_data->metaspace_non_null()->expand_and_allocate(word_size, mdtype);
259 if (result != NULL) {
260 return result;
261 }
262 JavaThread* jthr = JavaThread::current();
263 if (!jthr->in_critical()) {
264 // Wait for JNI critical section to be exited
265 GCLocker::stall_until_clear();
266 // The GC invoked by the last thread leaving the critical
267 // section will be a young collection and a full collection
268 // is (currently) needed for unloading classes so continue
269 // to the next iteration to get a full GC.
270 continue;
271 } else {
272 if (CheckJNICalls) {
273 fatal("Possible deadlock due to allocating while"
274 " in jni critical section");
275 }
276 return NULL;
277 }
278 }
279
280 { // Need lock to get self consistent gc_count's
281 MutexLocker ml(Heap_lock);
282 gc_count = Universe::heap()->total_collections();
283 full_gc_count = Universe::heap()->total_full_collections();
284 }
285
286 // Generate a VM operation
287 VM_CollectForMetadataAllocation op(loader_data,
288 word_size,
289 mdtype,
290 gc_count,
291 full_gc_count,
292 GCCause::_metadata_GC_threshold);
293 VMThread::execute(&op);
294
295 // If GC was locked out, try again. Check before checking success because the
296 // prologue could have succeeded and the GC still have been locked out.
297 if (op.gc_locked()) {
298 continue;
299 }
300
301 if (op.prologue_succeeded()) {
302 return op.result();
303 }
304 loop_count++;
305 if ((QueuedAllocationWarningCount > 0) &&
306 (loop_count % QueuedAllocationWarningCount == 0)) {
307 log_warning(gc, ergo)("satisfy_failed_metadata_allocation() retries %d times,"
308 " size=" SIZE_FORMAT, loop_count, word_size);
309 }
310 } while (true); // Until a GC is done
311 }
312
313 #ifndef PRODUCT
314 void CollectedHeap::check_for_bad_heap_word_value(HeapWord* addr, size_t size) {
315 if (CheckMemoryInitialization && ZapUnusedHeapArea) {
316 for (size_t slot = 0; slot < size; slot += 1) {
317 assert((*(intptr_t*) (addr + slot)) != ((intptr_t) badHeapWordVal),
318 "Found badHeapWordValue in post-allocation check");
319 }
320 }
321 }
322
323 void CollectedHeap::check_for_non_bad_heap_word_value(HeapWord* addr, size_t size) {
324 if (CheckMemoryInitialization && ZapUnusedHeapArea) {
325 for (size_t slot = 0; slot < size; slot += 1) {
326 assert((*(intptr_t*) (addr + slot)) == ((intptr_t) badHeapWordVal),
327 "Found non badHeapWordValue in pre-allocation check");
328 }
329 }
330 }
331 #endif // PRODUCT
332
333 #ifdef ASSERT
334 void CollectedHeap::check_for_valid_allocation_state() {
335 Thread *thread = Thread::current();
336 // How to choose between a pending exception and a potential
337 // OutOfMemoryError? Don't allow pending exceptions.
338 // This is a VM policy failure, so how do we exhaustively test it?
339 assert(!thread->has_pending_exception(),
340 "shouldn't be allocating with pending exception");
341 if (StrictSafepointChecks) {
342 assert(thread->allow_allocation(),
343 "Allocation done by thread for which allocation is blocked "
344 "by No_Allocation_Verifier!");
345 // Allocation of an oop can always invoke a safepoint,
346 // hence, the true argument
347 thread->check_for_valid_safepoint_state(true);
348 }
349 }
350 #endif
351
352 HeapWord* CollectedHeap::allocate_from_tlab_slow(Klass* klass, Thread* thread, size_t size) {
353
354 // Retain tlab and allocate object in shared space if
355 // the amount free in the tlab is too large to discard.
356 if (thread->tlab().free() > thread->tlab().refill_waste_limit()) {
357 thread->tlab().record_slow_allocation(size);
358 return NULL;
359 }
360
361 // Discard tlab and allocate a new one.
362 // To minimize fragmentation, the last TLAB may be smaller than the rest.
363 size_t new_tlab_size = thread->tlab().compute_size(size);
364
365 thread->tlab().clear_before_allocation();
366
367 if (new_tlab_size == 0) {
368 return NULL;
369 }
370
371 // Allocate a new TLAB requesting new_tlab_size. Any size
372 // between minimal and new_tlab_size is accepted.
373 size_t actual_tlab_size = 0;
374 size_t minimal_tlab_size = MAX2(ThreadLocalAllocBuffer::compute_min_size(size), MinTLABSize);
375 HeapWord* obj = Universe::heap()->allocate_new_tlab(minimal_tlab_size, new_tlab_size, &actual_tlab_size);
376 if (obj == NULL) {
377 return NULL;
378 }
379 assert(actual_tlab_size != 0, "Allocation succeeded but actual size not updated. obj at: " PTR_FORMAT " min: " SIZE_FORMAT ", desired: " SIZE_FORMAT,
380 p2i(obj), minimal_tlab_size, new_tlab_size);
381
382 AllocTracer::send_allocation_in_new_tlab(klass, obj, actual_tlab_size * HeapWordSize, size * HeapWordSize, thread);
383
384 if (ZeroTLAB) {
385 // ..and clear it.
386 Copy::zero_to_words(obj, actual_tlab_size);
387 } else {
388 // ...and zap just allocated object.
389 #ifdef ASSERT
390 // Skip mangling the space corresponding to the object header to
391 // ensure that the returned space is not considered parsable by
392 // any concurrent GC thread.
393 size_t hdr_size = oopDesc::header_size();
394 Copy::fill_to_words(obj + hdr_size, actual_tlab_size - hdr_size, badHeapWordVal);
395 #endif // ASSERT
396 }
397 thread->tlab().fill(obj, obj + size, actual_tlab_size);
398 return obj;
399 }
400
401 size_t CollectedHeap::max_tlab_size() const {
402 // TLABs can't be bigger than we can fill with a int[Integer.MAX_VALUE].
403 // This restriction could be removed by enabling filling with multiple arrays.
404 // If we compute that the reasonable way as
405 // header_size + ((sizeof(jint) * max_jint) / HeapWordSize)
406 // we'll overflow on the multiply, so we do the divide first.
407 // We actually lose a little by dividing first,
408 // but that just makes the TLAB somewhat smaller than the biggest array,
409 // which is fine, since we'll be able to fill that.
410 size_t max_int_size = typeArrayOopDesc::header_size(T_INT) +
411 sizeof(jint) *
412 ((juint) max_jint / (size_t) HeapWordSize);
413 return align_down(max_int_size, MinObjAlignment);
414 }
415
416 size_t CollectedHeap::filler_array_hdr_size() {
417 return align_object_offset(arrayOopDesc::header_size(T_INT)); // align to Long
418 }
419
420 size_t CollectedHeap::filler_array_min_size() {
421 return align_object_size(filler_array_hdr_size()); // align to MinObjAlignment
422 }
423
424 #ifdef ASSERT
425 void CollectedHeap::fill_args_check(HeapWord* start, size_t words)
426 {
427 assert(words >= min_fill_size(), "too small to fill");
428 assert(is_object_aligned(words), "unaligned size");
429 assert(Universe::heap()->is_in_reserved(start), "not in heap");
430 assert(Universe::heap()->is_in_reserved(start + words - 1), "not in heap");
431 }
432
433 void CollectedHeap::zap_filler_array(HeapWord* start, size_t words, bool zap)
434 {
435 if (ZapFillerObjects && zap) {
436 Copy::fill_to_words(start + filler_array_hdr_size(),
437 words - filler_array_hdr_size(), 0XDEAFBABE);
438 }
439 }
440 #endif // ASSERT
441
442 void
443 CollectedHeap::fill_with_array(HeapWord* start, size_t words, bool zap)
444 {
445 assert(words >= filler_array_min_size(), "too small for an array");
446 assert(words <= filler_array_max_size(), "too big for a single object");
447
448 const size_t payload_size = words - filler_array_hdr_size();
449 const size_t len = payload_size * HeapWordSize / sizeof(jint);
450 assert((int)len >= 0, "size too large " SIZE_FORMAT " becomes %d", words, (int)len);
451
452 // Set the length first for concurrent GC.
453 ((arrayOop)start)->set_length((int)len);
454 post_allocation_setup_common(Universe::intArrayKlassObj(), start);
455 DEBUG_ONLY(zap_filler_array(start, words, zap);)
456 }
457
458 void
459 CollectedHeap::fill_with_object_impl(HeapWord* start, size_t words, bool zap)
460 {
461 assert(words <= filler_array_max_size(), "too big for a single object");
462
463 if (words >= filler_array_min_size()) {
464 fill_with_array(start, words, zap);
465 } else if (words > 0) {
466 assert(words == min_fill_size(), "unaligned size");
467 post_allocation_setup_common(SystemDictionary::Object_klass(), start);
468 }
469 }
470
471 void CollectedHeap::fill_with_object(HeapWord* start, size_t words, bool zap)
472 {
473 DEBUG_ONLY(fill_args_check(start, words);)
474 HandleMark hm; // Free handles before leaving.
475 fill_with_object_impl(start, words, zap);
476 }
477
478 void CollectedHeap::fill_with_objects(HeapWord* start, size_t words, bool zap)
479 {
480 DEBUG_ONLY(fill_args_check(start, words);)
481 HandleMark hm; // Free handles before leaving.
482
483 // Multiple objects may be required depending on the filler array maximum size. Fill
484 // the range up to that with objects that are filler_array_max_size sized. The
485 // remainder is filled with a single object.
486 const size_t min = min_fill_size();
487 const size_t max = filler_array_max_size();
488 while (words > max) {
489 const size_t cur = (words - max) >= min ? max : max - min;
490 fill_with_array(start, cur, zap);
491 start += cur;
492 words -= cur;
493 }
494
495 fill_with_object_impl(start, words, zap);
496 }
497
498 HeapWord* CollectedHeap::allocate_new_tlab(size_t min_word_size,
499 size_t desired_word_size,
500 size_t* actual_word_size) {
501 guarantee(false, "thread-local allocation buffers not supported");
502 return NULL;
503 }
504
505 void CollectedHeap::ensure_parsability(bool retire_tlabs) {
506 // The second disjunct in the assertion below makes a concession
507 // for the start-up verification done while the VM is being
508 // created. Callers be careful that you know that mutators
509 // aren't going to interfere -- for instance, this is permissible
510 // if we are still single-threaded and have either not yet
511 // started allocating (nothing much to verify) or we have
512 // started allocating but are now a full-fledged JavaThread
513 // (and have thus made our TLAB's) available for filling.
514 assert(SafepointSynchronize::is_at_safepoint() ||
515 !is_init_completed(),
516 "Should only be called at a safepoint or at start-up"
517 " otherwise concurrent mutator activity may make heap "
518 " unparsable again");
519 const bool use_tlab = UseTLAB;
520 // The main thread starts allocating via a TLAB even before it
521 // has added itself to the threads list at vm boot-up.
522 JavaThreadIteratorWithHandle jtiwh;
523 assert(!use_tlab || jtiwh.length() > 0,
524 "Attempt to fill tlabs before main thread has been added"
525 " to threads list is doomed to failure!");
526 BarrierSet *bs = BarrierSet::barrier_set();
527 for (; JavaThread *thread = jtiwh.next(); ) {
528 if (use_tlab) thread->tlab().make_parsable(retire_tlabs);
529 bs->make_parsable(thread);
530 }
531 }
532
533 void CollectedHeap::accumulate_statistics_all_tlabs() {
534 if (UseTLAB) {
535 assert(SafepointSynchronize::is_at_safepoint() ||
536 !is_init_completed(),
537 "should only accumulate statistics on tlabs at safepoint");
538
539 ThreadLocalAllocBuffer::accumulate_statistics_before_gc();
540 }
541 }
542
543 void CollectedHeap::resize_all_tlabs() {
544 if (UseTLAB) {
545 assert(SafepointSynchronize::is_at_safepoint() ||
546 !is_init_completed(),
547 "should only resize tlabs at safepoint");
548
549 ThreadLocalAllocBuffer::resize_all_tlabs();
550 }
551 }
552
553 void CollectedHeap::full_gc_dump(GCTimer* timer, bool before) {
554 assert(timer != NULL, "timer is null");
555 if ((HeapDumpBeforeFullGC && before) || (HeapDumpAfterFullGC && !before)) {
556 GCTraceTime(Info, gc) tm(before ? "Heap Dump (before full gc)" : "Heap Dump (after full gc)", timer);
557 HeapDumper::dump_heap();
558 }
559
560 LogTarget(Trace, gc, classhisto) lt;
561 if (lt.is_enabled()) {
562 GCTraceTime(Trace, gc, classhisto) tm(before ? "Class Histogram (before full gc)" : "Class Histogram (after full gc)", timer);
563 ResourceMark rm;
564 LogStream ls(lt);
565 VM_GC_HeapInspection inspector(&ls, false /* ! full gc */);
566 inspector.doit();
567 }
568 }
569
570 void CollectedHeap::pre_full_gc_dump(GCTimer* timer) {
571 full_gc_dump(timer, true);
572 }
573
574 void CollectedHeap::post_full_gc_dump(GCTimer* timer) {
575 full_gc_dump(timer, false);
576 }
577
578 void CollectedHeap::initialize_reserved_region(HeapWord *start, HeapWord *end) {
579 // It is important to do this in a way such that concurrent readers can't
580 // temporarily think something is in the heap. (Seen this happen in asserts.)
581 _reserved.set_word_size(0);
582 _reserved.set_start(start);
583 _reserved.set_end(end);
584 }
585
586 void CollectedHeap::post_initialize() {
587 initialize_serviceability();
588 }
589
590 #ifndef PRODUCT
591
592 bool CollectedHeap::promotion_should_fail(volatile size_t* count) {
593 // Access to count is not atomic; the value does not have to be exact.
594 if (PromotionFailureALot) {
595 const size_t gc_num = total_collections();
596 const size_t elapsed_gcs = gc_num - _promotion_failure_alot_gc_number;
597 if (elapsed_gcs >= PromotionFailureALotInterval) {
598 // Test for unsigned arithmetic wrap-around.
599 if (++*count >= PromotionFailureALotCount) {
600 *count = 0;
601 return true;
602 }
603 }
604 }
605 return false;
606 }
607
608 bool CollectedHeap::promotion_should_fail() {
609 return promotion_should_fail(&_promotion_failure_alot_count);
610 }
611
612 void CollectedHeap::reset_promotion_should_fail(volatile size_t* count) {
613 if (PromotionFailureALot) {
614 _promotion_failure_alot_gc_number = total_collections();
615 *count = 0;
616 }
617 }
618
619 void CollectedHeap::reset_promotion_should_fail() {
620 reset_promotion_should_fail(&_promotion_failure_alot_count);
621 }
622
623 #endif // #ifndef PRODUCT
624
625 bool CollectedHeap::supports_object_pinning() const {
626 return false;
627 }
628
629 oop CollectedHeap::pin_object(JavaThread* thread, oop obj) {
630 ShouldNotReachHere();
631 return NULL;
632 }
633
634 void CollectedHeap::unpin_object(JavaThread* thread, oop obj) {
635 ShouldNotReachHere();
636 }