1 /*
2 * Copyright (c) 2001, 2022, 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/classLoaderData.hpp"
27 #include "classfile/vmClasses.hpp"
28 #include "gc/shared/allocTracer.hpp"
29 #include "gc/shared/barrierSet.hpp"
30 #include "gc/shared/collectedHeap.hpp"
31 #include "gc/shared/collectedHeap.inline.hpp"
32 #include "gc/shared/gcLocker.inline.hpp"
33 #include "gc/shared/gcHeapSummary.hpp"
34 #include "gc/shared/stringdedup/stringDedup.hpp"
35 #include "gc/shared/gcTrace.hpp"
36 #include "gc/shared/gcTraceTime.inline.hpp"
37 #include "gc/shared/gcVMOperations.hpp"
38 #include "gc/shared/gcWhen.hpp"
39 #include "gc/shared/gc_globals.hpp"
40 #include "gc/shared/memAllocator.hpp"
41 #include "gc/shared/tlab_globals.hpp"
42 #include "logging/log.hpp"
43 #include "logging/logStream.hpp"
44 #include "memory/classLoaderMetaspace.hpp"
45 #include "memory/metaspaceUtils.hpp"
46 #include "memory/resourceArea.hpp"
47 #include "memory/universe.hpp"
48 #include "oops/instanceMirrorKlass.hpp"
49 #include "oops/oop.inline.hpp"
50 #include "runtime/handles.inline.hpp"
51 #include "runtime/init.hpp"
52 #include "runtime/javaThread.hpp"
53 #include "runtime/perfData.hpp"
54 #include "runtime/threadSMR.hpp"
55 #include "runtime/vmThread.hpp"
56 #include "services/heapDumper.hpp"
57 #include "utilities/align.hpp"
58 #include "utilities/copy.hpp"
59 #include "utilities/events.hpp"
60
61 class ClassLoaderData;
62
63 size_t CollectedHeap::_lab_alignment_reserve = ~(size_t)0;
64 Klass* CollectedHeap::_filler_object_klass = NULL;
65 size_t CollectedHeap::_filler_array_max_size = 0;
66 size_t CollectedHeap::_stack_chunk_max_size = 0;
67
68 class GCMessage : public FormatBuffer<1024> {
69 public:
70 bool is_before;
71 };
72
73 template <>
74 void EventLogBase<GCMessage>::print(outputStream* st, GCMessage& m) {
75 st->print_cr("GC heap %s", m.is_before ? "before" : "after");
76 st->print_raw(m);
77 }
78
79 class GCHeapLog : public EventLogBase<GCMessage> {
80 private:
81 void log_heap(CollectedHeap* heap, bool before);
82
83 public:
84 GCHeapLog() : EventLogBase<GCMessage>("GC Heap History", "gc") {}
85
86 void log_heap_before(CollectedHeap* heap) {
87 log_heap(heap, true);
88 }
89 void log_heap_after(CollectedHeap* heap) {
90 log_heap(heap, false);
91 }
92 };
93
94 void GCHeapLog::log_heap(CollectedHeap* heap, bool before) {
95 if (!should_log()) {
96 return;
97 }
98
99 double timestamp = fetch_timestamp();
100 MutexLocker ml(&_mutex, Mutex::_no_safepoint_check_flag);
101 int index = compute_log_index();
102 _records[index].thread = NULL; // Its the GC thread so it's not that interesting.
103 _records[index].timestamp = timestamp;
104 _records[index].data.is_before = before;
105 stringStream st(_records[index].data.buffer(), _records[index].data.size());
106
107 st.print_cr("{Heap %s GC invocations=%u (full %u):",
108 before ? "before" : "after",
109 heap->total_collections(),
110 heap->total_full_collections());
111
112 heap->print_on(&st);
113 st.print_cr("}");
114 }
115
116 ParallelObjectIterator::ParallelObjectIterator(uint thread_num) :
117 _impl(Universe::heap()->parallel_object_iterator(thread_num))
118 {}
119
120 ParallelObjectIterator::~ParallelObjectIterator() {
121 delete _impl;
122 }
123
124 void ParallelObjectIterator::object_iterate(ObjectClosure* cl, uint worker_id) {
125 _impl->object_iterate(cl, worker_id);
126 }
127
128 size_t CollectedHeap::unused() const {
129 MutexLocker ml(Heap_lock);
130 return capacity() - used();
131 }
132
133 VirtualSpaceSummary CollectedHeap::create_heap_space_summary() {
134 size_t capacity_in_words = capacity() / HeapWordSize;
135
136 return VirtualSpaceSummary(
137 _reserved.start(), _reserved.start() + capacity_in_words, _reserved.end());
138 }
139
140 GCHeapSummary CollectedHeap::create_heap_summary() {
141 VirtualSpaceSummary heap_space = create_heap_space_summary();
142 return GCHeapSummary(heap_space, used());
143 }
144
145 MetaspaceSummary CollectedHeap::create_metaspace_summary() {
146 const MetaspaceChunkFreeListSummary& ms_chunk_free_list_summary =
147 MetaspaceUtils::chunk_free_list_summary(Metaspace::NonClassType);
148 const MetaspaceChunkFreeListSummary& class_chunk_free_list_summary =
149 MetaspaceUtils::chunk_free_list_summary(Metaspace::ClassType);
150 return MetaspaceSummary(MetaspaceGC::capacity_until_GC(),
151 MetaspaceUtils::get_combined_statistics(),
152 ms_chunk_free_list_summary, class_chunk_free_list_summary);
153 }
154
155 void CollectedHeap::print_heap_before_gc() {
156 LogTarget(Debug, gc, heap) lt;
157 if (lt.is_enabled()) {
158 LogStream ls(lt);
159 ls.print_cr("Heap before GC invocations=%u (full %u):", total_collections(), total_full_collections());
160 ResourceMark rm;
161 print_on(&ls);
162 }
163
164 if (_gc_heap_log != NULL) {
165 _gc_heap_log->log_heap_before(this);
166 }
167 }
168
169 void CollectedHeap::print_heap_after_gc() {
170 LogTarget(Debug, gc, heap) lt;
171 if (lt.is_enabled()) {
172 LogStream ls(lt);
173 ls.print_cr("Heap after GC invocations=%u (full %u):", total_collections(), total_full_collections());
174 ResourceMark rm;
175 print_on(&ls);
176 }
177
178 if (_gc_heap_log != NULL) {
179 _gc_heap_log->log_heap_after(this);
180 }
181 }
182
183 void CollectedHeap::print() const { print_on(tty); }
184
185 void CollectedHeap::print_on_error(outputStream* st) const {
186 st->print_cr("Heap:");
187 print_extended_on(st);
188 st->cr();
189
190 BarrierSet* bs = BarrierSet::barrier_set();
191 if (bs != NULL) {
192 bs->print_on(st);
193 }
194 }
195
196 void CollectedHeap::trace_heap(GCWhen::Type when, const GCTracer* gc_tracer) {
197 const GCHeapSummary& heap_summary = create_heap_summary();
198 gc_tracer->report_gc_heap_summary(when, heap_summary);
199
200 const MetaspaceSummary& metaspace_summary = create_metaspace_summary();
201 gc_tracer->report_metaspace_summary(when, metaspace_summary);
202 }
203
204 void CollectedHeap::trace_heap_before_gc(const GCTracer* gc_tracer) {
205 trace_heap(GCWhen::BeforeGC, gc_tracer);
206 }
207
208 void CollectedHeap::trace_heap_after_gc(const GCTracer* gc_tracer) {
209 trace_heap(GCWhen::AfterGC, gc_tracer);
210 }
211
212 // Default implementation, for collectors that don't support the feature.
213 bool CollectedHeap::supports_concurrent_gc_breakpoints() const {
214 return false;
215 }
216
217 bool CollectedHeap::is_oop(oop object) const {
218 if (!is_object_aligned(object)) {
219 return false;
220 }
221
222 if (!is_in(object)) {
223 return false;
224 }
225
226 return true;
227 }
228
229 // Memory state functions.
230
231
232 CollectedHeap::CollectedHeap() :
233 _capacity_at_last_gc(0),
234 _used_at_last_gc(0),
235 _is_gc_active(false),
236 _last_whole_heap_examined_time_ns(os::javaTimeNanos()),
237 _total_collections(0),
238 _total_full_collections(0),
239 _gc_cause(GCCause::_no_gc),
240 _gc_lastcause(GCCause::_no_gc)
241 {
242 // If the minimum object size is greater than MinObjAlignment, we can
243 // end up with a shard at the end of the buffer that's smaller than
244 // the smallest object. We can't allow that because the buffer must
245 // look like it's full of objects when we retire it, so we make
246 // sure we have enough space for a filler int array object.
247 size_t min_size = min_dummy_object_size();
248 _lab_alignment_reserve = min_size > (size_t)MinObjAlignment ? align_object_size(min_size) : 0;
249
250 const size_t max_len = size_t(arrayOopDesc::max_array_length(T_INT));
251 const size_t elements_per_word = HeapWordSize / sizeof(jint);
252 int header_size_in_bytes = arrayOopDesc::base_offset_in_bytes(T_INT);
253 assert(header_size_in_bytes % sizeof(jint) == 0, "must be aligned to int");
254 int header_size_in_ints = header_size_in_bytes / sizeof(jint);
255 _filler_array_max_size = align_object_size((header_size_in_ints + max_len) / elements_per_word);
256
257 NOT_PRODUCT(_promotion_failure_alot_count = 0;)
258 NOT_PRODUCT(_promotion_failure_alot_gc_number = 0;)
259
260 if (UsePerfData) {
261 EXCEPTION_MARK;
262
263 // create the gc cause jvmstat counters
264 _perf_gc_cause = PerfDataManager::create_string_variable(SUN_GC, "cause",
265 80, GCCause::to_string(_gc_cause), CHECK);
266
267 _perf_gc_lastcause =
268 PerfDataManager::create_string_variable(SUN_GC, "lastCause",
269 80, GCCause::to_string(_gc_lastcause), CHECK);
270 }
271
272 // Create the ring log
273 if (LogEvents) {
274 _gc_heap_log = new GCHeapLog();
275 } else {
276 _gc_heap_log = NULL;
277 }
278 }
279
280 // This interface assumes that it's being called by the
281 // vm thread. It collects the heap assuming that the
282 // heap lock is already held and that we are executing in
283 // the context of the vm thread.
284 void CollectedHeap::collect_as_vm_thread(GCCause::Cause cause) {
285 Thread* thread = Thread::current();
286 assert(thread->is_VM_thread(), "Precondition#1");
287 assert(Heap_lock->is_locked(), "Precondition#2");
288 GCCauseSetter gcs(this, cause);
289 switch (cause) {
290 case GCCause::_codecache_GC_threshold:
291 case GCCause::_heap_inspection:
292 case GCCause::_heap_dump:
293 case GCCause::_metadata_GC_threshold : {
294 HandleMark hm(thread);
295 do_full_collection(false); // don't clear all soft refs
296 break;
297 }
298 case GCCause::_archive_time_gc:
299 case GCCause::_metadata_GC_clear_soft_refs: {
300 HandleMark hm(thread);
301 do_full_collection(true); // do clear all soft refs
302 break;
303 }
304 default:
305 ShouldNotReachHere(); // Unexpected use of this function
306 }
307 }
308
309 MetaWord* CollectedHeap::satisfy_failed_metadata_allocation(ClassLoaderData* loader_data,
310 size_t word_size,
311 Metaspace::MetadataType mdtype) {
312 uint loop_count = 0;
313 uint gc_count = 0;
314 uint full_gc_count = 0;
315
316 assert(!Heap_lock->owned_by_self(), "Should not be holding the Heap_lock");
317
318 do {
319 MetaWord* result = loader_data->metaspace_non_null()->allocate(word_size, mdtype);
320 if (result != NULL) {
321 return result;
322 }
323
324 if (GCLocker::is_active_and_needs_gc()) {
325 // If the GCLocker is active, just expand and allocate.
326 // If that does not succeed, wait if this thread is not
327 // in a critical section itself.
328 result = loader_data->metaspace_non_null()->expand_and_allocate(word_size, mdtype);
329 if (result != NULL) {
330 return result;
331 }
332 JavaThread* jthr = JavaThread::current();
333 if (!jthr->in_critical()) {
334 // Wait for JNI critical section to be exited
335 GCLocker::stall_until_clear();
336 // The GC invoked by the last thread leaving the critical
337 // section will be a young collection and a full collection
338 // is (currently) needed for unloading classes so continue
339 // to the next iteration to get a full GC.
340 continue;
341 } else {
342 if (CheckJNICalls) {
343 fatal("Possible deadlock due to allocating while"
344 " in jni critical section");
345 }
346 return NULL;
347 }
348 }
349
350 { // Need lock to get self consistent gc_count's
351 MutexLocker ml(Heap_lock);
352 gc_count = Universe::heap()->total_collections();
353 full_gc_count = Universe::heap()->total_full_collections();
354 }
355
356 // Generate a VM operation
357 VM_CollectForMetadataAllocation op(loader_data,
358 word_size,
359 mdtype,
360 gc_count,
361 full_gc_count,
362 GCCause::_metadata_GC_threshold);
363 VMThread::execute(&op);
364
365 // If GC was locked out, try again. Check before checking success because the
366 // prologue could have succeeded and the GC still have been locked out.
367 if (op.gc_locked()) {
368 continue;
369 }
370
371 if (op.prologue_succeeded()) {
372 return op.result();
373 }
374 loop_count++;
375 if ((QueuedAllocationWarningCount > 0) &&
376 (loop_count % QueuedAllocationWarningCount == 0)) {
377 log_warning(gc, ergo)("satisfy_failed_metadata_allocation() retries %d times,"
378 " size=" SIZE_FORMAT, loop_count, word_size);
379 }
380 } while (true); // Until a GC is done
381 }
382
383 MemoryUsage CollectedHeap::memory_usage() {
384 return MemoryUsage(InitialHeapSize, used(), capacity(), max_capacity());
385 }
386
387 void CollectedHeap::set_gc_cause(GCCause::Cause v) {
388 if (UsePerfData) {
389 _gc_lastcause = _gc_cause;
390 _perf_gc_lastcause->set_value(GCCause::to_string(_gc_lastcause));
391 _perf_gc_cause->set_value(GCCause::to_string(v));
392 }
393 _gc_cause = v;
394 }
395
396 #ifndef PRODUCT
397 void CollectedHeap::check_for_non_bad_heap_word_value(HeapWord* addr, size_t size) {
398 if (CheckMemoryInitialization && ZapUnusedHeapArea) {
399 // please note mismatch between size (in 32/64 bit words), and ju_addr that always point to a 32 bit word
400 for (juint* ju_addr = reinterpret_cast<juint*>(addr); ju_addr < reinterpret_cast<juint*>(addr + size); ++ju_addr) {
401 assert(*ju_addr == badHeapWordVal, "Found non badHeapWordValue in pre-allocation check");
402 }
403 }
404 }
405 #endif // PRODUCT
406
407 size_t CollectedHeap::max_tlab_size() const {
408 // TLABs can't be bigger than we can fill with a int[Integer.MAX_VALUE].
409 // This restriction could be removed by enabling filling with multiple arrays.
410 // If we compute that the reasonable way as
411 // header_size + ((sizeof(jint) * max_jint) / HeapWordSize)
412 // we'll overflow on the multiply, so we do the divide first.
413 // We actually lose a little by dividing first,
414 // but that just makes the TLAB somewhat smaller than the biggest array,
415 // which is fine, since we'll be able to fill that.
416 int header_size_in_bytes = typeArrayOopDesc::base_offset_in_bytes(T_INT);
417 assert(header_size_in_bytes % sizeof(jint) == 0, "header size must align to int");
418 size_t max_int_size = header_size_in_bytes / HeapWordSize +
419 sizeof(jint) *
420 ((juint) max_jint / (size_t) HeapWordSize);
421 return align_down(max_int_size, MinObjAlignment);
422 }
423
424 size_t CollectedHeap::filler_array_min_size() {
425 int aligned_header_size_words = align_up(arrayOopDesc::base_offset_in_bytes(T_INT), HeapWordSize) / HeapWordSize;
426 return align_object_size(aligned_header_size_words); // align to MinObjAlignment
427 }
428
429 void CollectedHeap::zap_filler_array_with(HeapWord* start, size_t words, juint value) {
430 int payload_start = align_up(arrayOopDesc::base_offset_in_bytes(T_INT), HeapWordSize) / HeapWordSize;
431 Copy::fill_to_words(start + payload_start,
432 words - payload_start, value);
433 }
434
435 #ifdef ASSERT
436 void CollectedHeap::fill_args_check(HeapWord* start, size_t words)
437 {
438 assert(words >= min_fill_size(), "too small to fill");
439 assert(is_object_aligned(words), "unaligned size");
440 }
441
442 void CollectedHeap::zap_filler_array(HeapWord* start, size_t words, bool zap)
443 {
444 if (ZapFillerObjects && zap) {
445 zap_filler_array_with(start, words, 0XDEAFBABE);
446 }
447 }
448 #endif // ASSERT
449
450 void
451 CollectedHeap::fill_with_array(HeapWord* start, size_t words, bool zap)
452 {
453 assert(words >= filler_array_min_size(), "too small for an array");
454 assert(words <= filler_array_max_size(), "too big for a single object");
455
456 const size_t payload_size_bytes = words * HeapWordSize - arrayOopDesc::base_offset_in_bytes(T_INT);
457 assert(payload_size_bytes % sizeof(jint) == 0, "must be int aligned");
458 const size_t len = payload_size_bytes / sizeof(jint);
459 assert((int)len >= 0, "size too large " SIZE_FORMAT " becomes %d", words, (int)len);
460
461 ObjArrayAllocator allocator(Universe::fillerArrayKlassObj(), words, (int)len, /* do_zero */ false);
462 allocator.initialize(start);
463 if (DumpSharedSpaces) {
464 // This array is written into the CDS archive. Make sure it
465 // has deterministic contents.
466 zap_filler_array_with(start, words, 0);
467 } else {
468 DEBUG_ONLY(zap_filler_array(start, words, zap);)
469 }
470 }
471
472 void
473 CollectedHeap::fill_with_object_impl(HeapWord* start, size_t words, bool zap)
474 {
475 assert(words <= filler_array_max_size(), "too big for a single object");
476
477 if (words >= filler_array_min_size()) {
478 fill_with_array(start, words, zap);
479 } else if (words > 0) {
480 assert(words == min_fill_size(), "unaligned size");
481 ObjAllocator allocator(CollectedHeap::filler_object_klass(), words);
482 allocator.initialize(start);
483 }
484 }
485
486 void CollectedHeap::fill_with_object(HeapWord* start, size_t words, bool zap)
487 {
488 DEBUG_ONLY(fill_args_check(start, words);)
489 HandleMark hm(Thread::current()); // Free handles before leaving.
490 fill_with_object_impl(start, words, zap);
491 }
492
493 void CollectedHeap::fill_with_objects(HeapWord* start, size_t words, bool zap)
494 {
495 DEBUG_ONLY(fill_args_check(start, words);)
496 HandleMark hm(Thread::current()); // Free handles before leaving.
497
498 // Multiple objects may be required depending on the filler array maximum size. Fill
499 // the range up to that with objects that are filler_array_max_size sized. The
500 // remainder is filled with a single object.
501 const size_t min = min_fill_size();
502 const size_t max = filler_array_max_size();
503 while (words > max) {
504 const size_t cur = (words - max) >= min ? max : max - min;
505 fill_with_array(start, cur, zap);
506 start += cur;
507 words -= cur;
508 }
509
510 fill_with_object_impl(start, words, zap);
511 }
512
513 void CollectedHeap::fill_with_dummy_object(HeapWord* start, HeapWord* end, bool zap) {
514 CollectedHeap::fill_with_object(start, end, zap);
515 }
516
517 HeapWord* CollectedHeap::allocate_new_tlab(size_t min_size,
518 size_t requested_size,
519 size_t* actual_size) {
520 guarantee(false, "thread-local allocation buffers not supported");
521 return NULL;
522 }
523
524 void CollectedHeap::ensure_parsability(bool retire_tlabs) {
525 assert(SafepointSynchronize::is_at_safepoint() || !is_init_completed(),
526 "Should only be called at a safepoint or at start-up");
527
528 ThreadLocalAllocStats stats;
529
530 for (JavaThreadIteratorWithHandle jtiwh; JavaThread *thread = jtiwh.next();) {
531 BarrierSet::barrier_set()->make_parsable(thread);
532 if (UseTLAB) {
533 if (retire_tlabs) {
534 thread->tlab().retire(&stats);
535 } else {
536 thread->tlab().make_parsable();
537 }
538 }
539 }
540
541 stats.publish();
542 }
543
544 void CollectedHeap::resize_all_tlabs() {
545 assert(SafepointSynchronize::is_at_safepoint() || !is_init_completed(),
546 "Should only resize tlabs at safepoint");
547
548 if (UseTLAB && ResizeTLAB) {
549 for (JavaThreadIteratorWithHandle jtiwh; JavaThread *thread = jtiwh.next(); ) {
550 thread->tlab().resize();
551 }
552 }
553 }
554
555 jlong CollectedHeap::millis_since_last_whole_heap_examined() {
556 return (os::javaTimeNanos() - _last_whole_heap_examined_time_ns) / NANOSECS_PER_MILLISEC;
557 }
558
559 void CollectedHeap::record_whole_heap_examined_timestamp() {
560 _last_whole_heap_examined_time_ns = os::javaTimeNanos();
561 }
562
563 void CollectedHeap::full_gc_dump(GCTimer* timer, bool before) {
564 assert(timer != NULL, "timer is null");
565 if ((HeapDumpBeforeFullGC && before) || (HeapDumpAfterFullGC && !before)) {
566 GCTraceTime(Info, gc) tm(before ? "Heap Dump (before full gc)" : "Heap Dump (after full gc)", timer);
567 HeapDumper::dump_heap();
568 }
569
570 LogTarget(Trace, gc, classhisto) lt;
571 if (lt.is_enabled()) {
572 GCTraceTime(Trace, gc, classhisto) tm(before ? "Class Histogram (before full gc)" : "Class Histogram (after full gc)", timer);
573 ResourceMark rm;
574 LogStream ls(lt);
575 VM_GC_HeapInspection inspector(&ls, false /* ! full gc */);
576 inspector.doit();
577 }
578 }
579
580 void CollectedHeap::pre_full_gc_dump(GCTimer* timer) {
581 full_gc_dump(timer, true);
582 }
583
584 void CollectedHeap::post_full_gc_dump(GCTimer* timer) {
585 full_gc_dump(timer, false);
586 }
587
588 void CollectedHeap::initialize_reserved_region(const ReservedHeapSpace& rs) {
589 // It is important to do this in a way such that concurrent readers can't
590 // temporarily think something is in the heap. (Seen this happen in asserts.)
591 _reserved.set_word_size(0);
592 _reserved.set_start((HeapWord*)rs.base());
593 _reserved.set_end((HeapWord*)rs.end());
594 }
595
596 void CollectedHeap::post_initialize() {
597 StringDedup::initialize();
598 initialize_serviceability();
599 }
600
601 #ifndef PRODUCT
602
603 bool CollectedHeap::promotion_should_fail(volatile size_t* count) {
604 // Access to count is not atomic; the value does not have to be exact.
605 if (PromotionFailureALot) {
606 const size_t gc_num = total_collections();
607 const size_t elapsed_gcs = gc_num - _promotion_failure_alot_gc_number;
608 if (elapsed_gcs >= PromotionFailureALotInterval) {
609 // Test for unsigned arithmetic wrap-around.
610 if (++*count >= PromotionFailureALotCount) {
611 *count = 0;
612 return true;
613 }
614 }
615 }
616 return false;
617 }
618
619 bool CollectedHeap::promotion_should_fail() {
620 return promotion_should_fail(&_promotion_failure_alot_count);
621 }
622
623 void CollectedHeap::reset_promotion_should_fail(volatile size_t* count) {
624 if (PromotionFailureALot) {
625 _promotion_failure_alot_gc_number = total_collections();
626 *count = 0;
627 }
628 }
629
630 void CollectedHeap::reset_promotion_should_fail() {
631 reset_promotion_should_fail(&_promotion_failure_alot_count);
632 }
633
634 #endif // #ifndef PRODUCT
635
636 bool CollectedHeap::supports_object_pinning() const {
637 return false;
638 }
639
640 oop CollectedHeap::pin_object(JavaThread* thread, oop obj) {
641 ShouldNotReachHere();
642 return NULL;
643 }
644
645 void CollectedHeap::unpin_object(JavaThread* thread, oop obj) {
646 ShouldNotReachHere();
647 }
648
649 bool CollectedHeap::is_archived_object(oop object) const {
650 return false;
651 }
652
653 uint32_t CollectedHeap::hash_oop(oop obj) const {
654 const uintptr_t addr = cast_from_oop<uintptr_t>(obj);
655 return static_cast<uint32_t>(addr >> LogMinObjAlignment);
656 }
657
658 // It's the caller's responsibility to ensure glitch-freedom
659 // (if required).
660 void CollectedHeap::update_capacity_and_used_at_gc() {
661 _capacity_at_last_gc = capacity();
662 _used_at_last_gc = used();
663 }