1 /*
2 * Copyright (c) 2001, 2025, 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 "gc/parallel/objectStartArray.inline.hpp"
26 #include "gc/parallel/parallelArguments.hpp"
27 #include "gc/parallel/parallelInitLogger.hpp"
28 #include "gc/parallel/parallelScavengeHeap.inline.hpp"
29 #include "gc/parallel/psAdaptiveSizePolicy.hpp"
30 #include "gc/parallel/psMemoryPool.hpp"
31 #include "gc/parallel/psParallelCompact.inline.hpp"
32 #include "gc/parallel/psParallelCompactNew.inline.hpp"
33 #include "gc/parallel/psPromotionManager.hpp"
34 #include "gc/parallel/psScavenge.hpp"
35 #include "gc/parallel/psVMOperations.hpp"
36 #include "gc/shared/fullGCForwarding.inline.hpp"
37 #include "gc/shared/gcHeapSummary.hpp"
38 #include "gc/shared/gcLocker.inline.hpp"
39 #include "gc/shared/gcWhen.hpp"
40 #include "gc/shared/genArguments.hpp"
41 #include "gc/shared/locationPrinter.inline.hpp"
42 #include "gc/shared/scavengableNMethods.hpp"
43 #include "gc/shared/suspendibleThreadSet.hpp"
44 #include "logging/log.hpp"
45 #include "memory/iterator.hpp"
46 #include "memory/metaspaceCounters.hpp"
47 #include "memory/metaspaceUtils.hpp"
48 #include "memory/reservedSpace.hpp"
49 #include "memory/universe.hpp"
50 #include "oops/oop.inline.hpp"
51 #include "runtime/cpuTimeCounters.hpp"
52 #include "runtime/handles.inline.hpp"
53 #include "runtime/java.hpp"
54 #include "runtime/vmThread.hpp"
55 #include "services/memoryManager.hpp"
56 #include "utilities/macros.hpp"
57 #include "utilities/vmError.hpp"
58
59 PSYoungGen* ParallelScavengeHeap::_young_gen = nullptr;
60 PSOldGen* ParallelScavengeHeap::_old_gen = nullptr;
61 PSAdaptiveSizePolicy* ParallelScavengeHeap::_size_policy = nullptr;
62 PSGCAdaptivePolicyCounters* ParallelScavengeHeap::_gc_policy_counters = nullptr;
63
64 jint ParallelScavengeHeap::initialize() {
65 const size_t reserved_heap_size = ParallelArguments::heap_reserved_size_bytes();
66
67 ReservedHeapSpace heap_rs = Universe::reserve_heap(reserved_heap_size, HeapAlignment);
68
69 trace_actual_reserved_page_size(reserved_heap_size, heap_rs);
70
71 initialize_reserved_region(heap_rs);
72 // Layout the reserved space for the generations.
73 ReservedSpace old_rs = heap_rs.first_part(MaxOldSize, SpaceAlignment);
74 ReservedSpace young_rs = heap_rs.last_part(MaxOldSize, SpaceAlignment);
75 assert(young_rs.size() == MaxNewSize, "Didn't reserve all of the heap");
76
77 PSCardTable* card_table = new PSCardTable(_reserved);
78 card_table->initialize(old_rs.base(), young_rs.base());
79
80 CardTableBarrierSet* const barrier_set = new CardTableBarrierSet(card_table);
81 barrier_set->initialize();
82 BarrierSet::set_barrier_set(barrier_set);
83
84 // Set up WorkerThreads
85 _workers.initialize_workers();
86
87 // Create and initialize the generations.
88 _young_gen = new PSYoungGen(
89 young_rs,
90 NewSize,
91 MinNewSize,
92 MaxNewSize);
93 _old_gen = new PSOldGen(
94 old_rs,
95 OldSize,
96 MinOldSize,
97 MaxOldSize);
98
99 assert(young_gen()->max_gen_size() == young_rs.size(),"Consistency check");
100 assert(old_gen()->max_gen_size() == old_rs.size(), "Consistency check");
101
102 double max_gc_pause_sec = ((double) MaxGCPauseMillis)/1000.0;
103
104 const size_t eden_capacity = _young_gen->eden_space()->capacity_in_bytes();
105 const size_t old_capacity = _old_gen->capacity_in_bytes();
106 const size_t initial_promo_size = MIN2(eden_capacity, old_capacity);
107 _size_policy =
108 new PSAdaptiveSizePolicy(eden_capacity,
109 initial_promo_size,
110 young_gen()->to_space()->capacity_in_bytes(),
111 SpaceAlignment,
112 max_gc_pause_sec,
113 GCTimeRatio
114 );
115
116 assert((old_gen()->virtual_space()->high_boundary() ==
117 young_gen()->virtual_space()->low_boundary()),
118 "Boundaries must meet");
119 // initialize the policy counters - 2 collectors, 2 generations
120 _gc_policy_counters =
121 new PSGCAdaptivePolicyCounters("ParScav:MSC", 2, 2, _size_policy);
122
123 if (UseCompactObjectHeaders) {
124 if (!PSParallelCompactNew::initialize_aux_data()) {
125 return JNI_ENOMEM;
126 }
127 } else {
128 if (!PSParallelCompact::initialize_aux_data()) {
129 return JNI_ENOMEM;
130 }
131 }
132
133 // Create CPU time counter
134 CPUTimeCounters::create_counter(CPUTimeGroups::CPUTimeType::gc_parallel_workers);
135
136 ParallelInitLogger::print();
137
138 FullGCForwarding::initialize(_reserved);
139
140 return JNI_OK;
141 }
142
143 void ParallelScavengeHeap::initialize_serviceability() {
144
145 _eden_pool = new EdenMutableSpacePool(_young_gen,
146 _young_gen->eden_space(),
147 "PS Eden Space",
148 false /* support_usage_threshold */);
149
150 _survivor_pool = new SurvivorMutableSpacePool(_young_gen,
151 "PS Survivor Space",
152 false /* support_usage_threshold */);
153
154 _old_pool = new PSGenerationPool(_old_gen,
155 "PS Old Gen",
156 true /* support_usage_threshold */);
157
158 _young_manager = new GCMemoryManager("PS Scavenge");
159 _old_manager = new GCMemoryManager("PS MarkSweep");
160
161 _old_manager->add_pool(_eden_pool);
162 _old_manager->add_pool(_survivor_pool);
163 _old_manager->add_pool(_old_pool);
164
165 _young_manager->add_pool(_eden_pool);
166 _young_manager->add_pool(_survivor_pool);
167
168 }
169
170 void ParallelScavengeHeap::safepoint_synchronize_begin() {
171 if (UseStringDeduplication) {
172 SuspendibleThreadSet::synchronize();
173 }
174 }
175
176 void ParallelScavengeHeap::safepoint_synchronize_end() {
177 if (UseStringDeduplication) {
178 SuspendibleThreadSet::desynchronize();
179 }
180 }
181 class PSIsScavengable : public BoolObjectClosure {
182 bool do_object_b(oop obj) {
183 return ParallelScavengeHeap::heap()->is_in_young(obj);
184 }
185 };
186
187 static PSIsScavengable _is_scavengable;
188
189 void ParallelScavengeHeap::post_initialize() {
190 CollectedHeap::post_initialize();
191 // Need to init the tenuring threshold
192 PSScavenge::initialize();
193 if (UseCompactObjectHeaders) {
194 PSParallelCompactNew::post_initialize();
195 } else {
196 PSParallelCompact::post_initialize();
197 }
198 PSPromotionManager::initialize();
199
200 ScavengableNMethods::initialize(&_is_scavengable);
201 GCLocker::initialize();
202 }
203
204 void ParallelScavengeHeap::update_counters() {
205 young_gen()->update_counters();
206 old_gen()->update_counters();
207 MetaspaceCounters::update_performance_counters();
208 update_parallel_worker_threads_cpu_time();
209 }
210
211 size_t ParallelScavengeHeap::capacity() const {
212 size_t value = young_gen()->capacity_in_bytes() + old_gen()->capacity_in_bytes();
213 return value;
214 }
215
216 size_t ParallelScavengeHeap::used() const {
217 size_t value = young_gen()->used_in_bytes() + old_gen()->used_in_bytes();
218 return value;
219 }
220
221 size_t ParallelScavengeHeap::max_capacity() const {
222 size_t estimated = reserved_region().byte_size();
223 if (UseAdaptiveSizePolicy) {
224 estimated -= _size_policy->max_survivor_size(young_gen()->max_gen_size());
225 } else {
226 estimated -= young_gen()->to_space()->capacity_in_bytes();
227 }
228 return MAX2(estimated, capacity());
229 }
230
231 bool ParallelScavengeHeap::is_in(const void* p) const {
232 return young_gen()->is_in(p) || old_gen()->is_in(p);
233 }
234
235 bool ParallelScavengeHeap::is_in_reserved(const void* p) const {
236 return young_gen()->is_in_reserved(p) || old_gen()->is_in_reserved(p);
237 }
238
239 bool ParallelScavengeHeap::requires_barriers(stackChunkOop p) const {
240 return !is_in_young(p);
241 }
242
243 // There are two levels of allocation policy here.
244 //
245 // When an allocation request fails, the requesting thread must invoke a VM
246 // operation, transfer control to the VM thread, and await the results of a
247 // garbage collection. That is quite expensive, and we should avoid doing it
248 // multiple times if possible.
249 //
250 // To accomplish this, we have a basic allocation policy, and also a
251 // failed allocation policy.
252 //
253 // The basic allocation policy controls how you allocate memory without
254 // attempting garbage collection. It is okay to grab locks and
255 // expand the heap, if that can be done without coming to a safepoint.
256 // It is likely that the basic allocation policy will not be very
257 // aggressive.
258 //
259 // The failed allocation policy is invoked from the VM thread after
260 // the basic allocation policy is unable to satisfy a mem_allocate
261 // request. This policy needs to cover the entire range of collection,
262 // heap expansion, and out-of-memory conditions. It should make every
263 // attempt to allocate the requested memory.
264
265 // Basic allocation policy. Should never be called at a safepoint, or
266 // from the VM thread.
267 //
268 // This method must handle cases where many mem_allocate requests fail
269 // simultaneously. When that happens, only one VM operation will succeed,
270 // and the rest will not be executed. For that reason, this method loops
271 // during failed allocation attempts. If the java heap becomes exhausted,
272 // we rely on the size_policy object to force a bail out.
273 HeapWord* ParallelScavengeHeap::mem_allocate(size_t size,
274 bool* gc_overhead_limit_was_exceeded) {
275 assert(!SafepointSynchronize::is_at_safepoint(), "should not be at safepoint");
276 assert(Thread::current() != (Thread*)VMThread::vm_thread(), "should not be in vm thread");
277 assert(!Heap_lock->owned_by_self(), "this thread should not own the Heap_lock");
278
279 bool is_tlab = false;
280 return mem_allocate_work(size, is_tlab, gc_overhead_limit_was_exceeded);
281 }
282
283 HeapWord* ParallelScavengeHeap::mem_allocate_work(size_t size,
284 bool is_tlab,
285 bool* gc_overhead_limit_was_exceeded) {
286
287 // In general gc_overhead_limit_was_exceeded should be false so
288 // set it so here and reset it to true only if the gc time
289 // limit is being exceeded as checked below.
290 *gc_overhead_limit_was_exceeded = false;
291
292 HeapWord* result = young_gen()->allocate(size);
293
294 uint loop_count = 0;
295 uint gc_count = 0;
296
297 while (result == nullptr) {
298 // We don't want to have multiple collections for a single filled generation.
299 // To prevent this, each thread tracks the total_collections() value, and if
300 // the count has changed, does not do a new collection.
301 //
302 // The collection count must be read only while holding the heap lock. VM
303 // operations also hold the heap lock during collections. There is a lock
304 // contention case where thread A blocks waiting on the Heap_lock, while
305 // thread B is holding it doing a collection. When thread A gets the lock,
306 // the collection count has already changed. To prevent duplicate collections,
307 // The policy MUST attempt allocations during the same period it reads the
308 // total_collections() value!
309 {
310 MutexLocker ml(Heap_lock);
311 gc_count = total_collections();
312
313 result = young_gen()->allocate(size);
314 if (result != nullptr) {
315 return result;
316 }
317
318 // If certain conditions hold, try allocating from the old gen.
319 if (!is_tlab) {
320 result = mem_allocate_old_gen(size);
321 if (result != nullptr) {
322 return result;
323 }
324 }
325 }
326
327 assert(result == nullptr, "inv");
328 {
329 VM_ParallelCollectForAllocation op(size, is_tlab, gc_count);
330 VMThread::execute(&op);
331
332 // Did the VM operation execute? If so, return the result directly.
333 // This prevents us from looping until time out on requests that can
334 // not be satisfied.
335 if (op.gc_succeeded()) {
336 assert(is_in_or_null(op.result()), "result not in heap");
337
338 // Exit the loop if the gc time limit has been exceeded.
339 // The allocation must have failed above ("result" guarding
340 // this path is null) and the most recent collection has exceeded the
341 // gc overhead limit (although enough may have been collected to
342 // satisfy the allocation). Exit the loop so that an out-of-memory
343 // will be thrown (return a null ignoring the contents of
344 // op.result()),
345 // but clear gc_overhead_limit_exceeded so that the next collection
346 // starts with a clean slate (i.e., forgets about previous overhead
347 // excesses). Fill op.result() with a filler object so that the
348 // heap remains parsable.
349 const bool limit_exceeded = size_policy()->gc_overhead_limit_exceeded();
350 const bool softrefs_clear = soft_ref_policy()->all_soft_refs_clear();
351
352 if (limit_exceeded && softrefs_clear) {
353 *gc_overhead_limit_was_exceeded = true;
354 size_policy()->set_gc_overhead_limit_exceeded(false);
355 log_trace(gc)("ParallelScavengeHeap::mem_allocate: return null because gc_overhead_limit_exceeded is set");
356 if (op.result() != nullptr) {
357 CollectedHeap::fill_with_object(op.result(), size);
358 }
359 return nullptr;
360 }
361
362 return op.result();
363 }
364 }
365
366 // The policy object will prevent us from looping forever. If the
367 // time spent in gc crosses a threshold, we will bail out.
368 loop_count++;
369 if ((result == nullptr) && (QueuedAllocationWarningCount > 0) &&
370 (loop_count % QueuedAllocationWarningCount == 0)) {
371 log_warning(gc)("ParallelScavengeHeap::mem_allocate retries %d times", loop_count);
372 log_warning(gc)("\tsize=%zu", size);
373 }
374 }
375
376 return result;
377 }
378
379 HeapWord* ParallelScavengeHeap::allocate_old_gen_and_record(size_t size) {
380 assert_locked_or_safepoint(Heap_lock);
381 HeapWord* res = old_gen()->allocate(size);
382 if (res != nullptr) {
383 _size_policy->tenured_allocation(size * HeapWordSize);
384 }
385 return res;
386 }
387
388 HeapWord* ParallelScavengeHeap::mem_allocate_old_gen(size_t size) {
389 if (!should_alloc_in_eden(size)) {
390 // Size is too big for eden.
391 return allocate_old_gen_and_record(size);
392 }
393
394 return nullptr;
395 }
396
397 void ParallelScavengeHeap::do_full_collection(bool clear_all_soft_refs) {
398 if (UseCompactObjectHeaders) {
399 PSParallelCompactNew::invoke(clear_all_soft_refs, false /* serial */);
400 } else {
401 PSParallelCompact::invoke(clear_all_soft_refs);
402 }
403 }
404
405 HeapWord* ParallelScavengeHeap::expand_heap_and_allocate(size_t size, bool is_tlab) {
406 HeapWord* result = nullptr;
407
408 result = young_gen()->allocate(size);
409 if (result == nullptr && !is_tlab) {
410 result = old_gen()->expand_and_allocate(size);
411 }
412 return result; // Could be null if we are out of space.
413 }
414
415 HeapWord* ParallelScavengeHeap::satisfy_failed_allocation(size_t size, bool is_tlab) {
416 assert(size != 0, "precondition");
417
418 HeapWord* result = nullptr;
419
420 // If young-gen can handle this allocation, attempt young-gc firstly.
421 bool should_run_young_gc = is_tlab || should_alloc_in_eden(size);
422 collect_at_safepoint(!should_run_young_gc);
423
424 result = expand_heap_and_allocate(size, is_tlab);
425 if (result != nullptr) {
426 return result;
427 }
428
429 // If we reach this point, we're really out of memory. Try every trick
430 // we can to reclaim memory. Force collection of soft references. Force
431 // a complete compaction of the heap. Any additional methods for finding
432 // free memory should be here, especially if they are expensive. If this
433 // attempt fails, an OOM exception will be thrown.
434 {
435 // Make sure the heap is fully compacted
436 uintx old_interval = HeapMaximumCompactionInterval;
437 HeapMaximumCompactionInterval = 0;
438
439 const bool clear_all_soft_refs = true;
440 if (UseCompactObjectHeaders) {
441 PSParallelCompactNew::invoke(clear_all_soft_refs, false /* serial */);
442 } else {
443 PSParallelCompact::invoke(clear_all_soft_refs);
444 }
445
446 // Restore
447 HeapMaximumCompactionInterval = old_interval;
448 }
449
450 result = expand_heap_and_allocate(size, is_tlab);
451 if (result != nullptr) {
452 return result;
453 }
454
455 if (UseCompactObjectHeaders) {
456 PSParallelCompactNew::invoke(true /* clear_soft_refs */, true /* serial */);
457 }
458
459 result = expand_heap_and_allocate(size, is_tlab);
460 if (result != nullptr) {
461 return result;
462 }
463
464 // What else? We might try synchronous finalization later. If the total
465 // space available is large enough for the allocation, then a more
466 // complete compaction phase than we've tried so far might be
467 // appropriate.
468 return nullptr;
469 }
470
471
472 void ParallelScavengeHeap::ensure_parsability(bool retire_tlabs) {
473 CollectedHeap::ensure_parsability(retire_tlabs);
474 young_gen()->eden_space()->ensure_parsability();
475 }
476
477 size_t ParallelScavengeHeap::tlab_capacity(Thread* thr) const {
478 return young_gen()->eden_space()->tlab_capacity(thr);
479 }
480
481 size_t ParallelScavengeHeap::tlab_used(Thread* thr) const {
482 return young_gen()->eden_space()->tlab_used(thr);
483 }
484
485 size_t ParallelScavengeHeap::unsafe_max_tlab_alloc(Thread* thr) const {
486 return young_gen()->eden_space()->unsafe_max_tlab_alloc(thr);
487 }
488
489 HeapWord* ParallelScavengeHeap::allocate_new_tlab(size_t min_size, size_t requested_size, size_t* actual_size) {
490 bool dummy;
491 HeapWord* result = mem_allocate_work(requested_size /* size */,
492 true /* is_tlab */,
493 &dummy);
494 if (result != nullptr) {
495 *actual_size = requested_size;
496 }
497
498 return result;
499 }
500
501 void ParallelScavengeHeap::resize_all_tlabs() {
502 CollectedHeap::resize_all_tlabs();
503 }
504
505 void ParallelScavengeHeap::prune_scavengable_nmethods() {
506 ScavengableNMethods::prune_nmethods_not_into_young();
507 }
508
509 void ParallelScavengeHeap::prune_unlinked_nmethods() {
510 ScavengableNMethods::prune_unlinked_nmethods();
511 }
512
513 void ParallelScavengeHeap::collect(GCCause::Cause cause) {
514 assert(!Heap_lock->owned_by_self(),
515 "this thread should not own the Heap_lock");
516
517 uint gc_count = 0;
518 uint full_gc_count = 0;
519 {
520 MutexLocker ml(Heap_lock);
521 // This value is guarded by the Heap_lock
522 gc_count = total_collections();
523 full_gc_count = total_full_collections();
524 }
525
526 VM_ParallelGCCollect op(gc_count, full_gc_count, cause);
527 VMThread::execute(&op);
528 }
529
530 bool ParallelScavengeHeap::must_clear_all_soft_refs() {
531 return _gc_cause == GCCause::_metadata_GC_clear_soft_refs ||
532 _gc_cause == GCCause::_wb_full_gc;
533 }
534
535 void ParallelScavengeHeap::collect_at_safepoint(bool full) {
536 assert(!GCLocker::is_active(), "precondition");
537 bool clear_soft_refs = must_clear_all_soft_refs();
538
539 if (!full) {
540 bool success = PSScavenge::invoke(clear_soft_refs);
541 if (success) {
542 return;
543 }
544 // Upgrade to Full-GC if young-gc fails
545 }
546 if (UseCompactObjectHeaders) {
547 PSParallelCompactNew::invoke(clear_soft_refs, false /* serial */);
548 } else {
549 PSParallelCompact::invoke(clear_soft_refs);
550 }
551 }
552
553 void ParallelScavengeHeap::object_iterate(ObjectClosure* cl) {
554 young_gen()->object_iterate(cl);
555 old_gen()->object_iterate(cl);
556 }
557
558 // The HeapBlockClaimer is used during parallel iteration over the heap,
559 // allowing workers to claim heap areas ("blocks"), gaining exclusive rights to these.
560 // The eden and survivor spaces are treated as single blocks as it is hard to divide
561 // these spaces.
562 // The old space is divided into fixed-size blocks.
563 class HeapBlockClaimer : public StackObj {
564 size_t _claimed_index;
565
566 public:
567 static const size_t InvalidIndex = SIZE_MAX;
568 static const size_t EdenIndex = 0;
569 static const size_t SurvivorIndex = 1;
570 static const size_t NumNonOldGenClaims = 2;
571
572 HeapBlockClaimer() : _claimed_index(EdenIndex) { }
573 // Claim the block and get the block index.
574 size_t claim_and_get_block() {
575 size_t block_index;
576 block_index = Atomic::fetch_then_add(&_claimed_index, 1u);
577
578 PSOldGen* old_gen = ParallelScavengeHeap::heap()->old_gen();
579 size_t num_claims = old_gen->num_iterable_blocks() + NumNonOldGenClaims;
580
581 return block_index < num_claims ? block_index : InvalidIndex;
582 }
583 };
584
585 void ParallelScavengeHeap::object_iterate_parallel(ObjectClosure* cl,
586 HeapBlockClaimer* claimer) {
587 size_t block_index = claimer->claim_and_get_block();
588 // Iterate until all blocks are claimed
589 if (block_index == HeapBlockClaimer::EdenIndex) {
590 young_gen()->eden_space()->object_iterate(cl);
591 block_index = claimer->claim_and_get_block();
592 }
593 if (block_index == HeapBlockClaimer::SurvivorIndex) {
594 young_gen()->from_space()->object_iterate(cl);
595 young_gen()->to_space()->object_iterate(cl);
596 block_index = claimer->claim_and_get_block();
597 }
598 while (block_index != HeapBlockClaimer::InvalidIndex) {
599 old_gen()->object_iterate_block(cl, block_index - HeapBlockClaimer::NumNonOldGenClaims);
600 block_index = claimer->claim_and_get_block();
601 }
602 }
603
604 class PSScavengeParallelObjectIterator : public ParallelObjectIteratorImpl {
605 private:
606 ParallelScavengeHeap* _heap;
607 HeapBlockClaimer _claimer;
608
609 public:
610 PSScavengeParallelObjectIterator() :
611 _heap(ParallelScavengeHeap::heap()),
612 _claimer() {}
613
614 virtual void object_iterate(ObjectClosure* cl, uint worker_id) {
615 _heap->object_iterate_parallel(cl, &_claimer);
616 }
617 };
618
619 ParallelObjectIteratorImpl* ParallelScavengeHeap::parallel_object_iterator(uint thread_num) {
620 return new PSScavengeParallelObjectIterator();
621 }
622
623 HeapWord* ParallelScavengeHeap::block_start(const void* addr) const {
624 if (young_gen()->is_in_reserved(addr)) {
625 assert(young_gen()->is_in(addr),
626 "addr should be in allocated part of young gen");
627 // called from os::print_location by find or VMError
628 if (DebuggingContext::is_enabled() || VMError::is_error_reported()) {
629 return nullptr;
630 }
631 Unimplemented();
632 } else if (old_gen()->is_in_reserved(addr)) {
633 assert(old_gen()->is_in(addr),
634 "addr should be in allocated part of old gen");
635 return old_gen()->start_array()->object_start((HeapWord*)addr);
636 }
637 return nullptr;
638 }
639
640 bool ParallelScavengeHeap::block_is_obj(const HeapWord* addr) const {
641 return block_start(addr) == addr;
642 }
643
644 void ParallelScavengeHeap::prepare_for_verify() {
645 ensure_parsability(false); // no need to retire TLABs for verification
646 }
647
648 PSHeapSummary ParallelScavengeHeap::create_ps_heap_summary() {
649 PSOldGen* old = old_gen();
650 HeapWord* old_committed_end = (HeapWord*)old->virtual_space()->committed_high_addr();
651 HeapWord* old_reserved_start = old->reserved().start();
652 HeapWord* old_reserved_end = old->reserved().end();
653 VirtualSpaceSummary old_summary(old_reserved_start, old_committed_end, old_reserved_end);
654 SpaceSummary old_space(old_reserved_start, old_committed_end, old->used_in_bytes());
655
656 PSYoungGen* young = young_gen();
657 VirtualSpaceSummary young_summary(young->reserved().start(),
658 (HeapWord*)young->virtual_space()->committed_high_addr(), young->reserved().end());
659
660 MutableSpace* eden = young_gen()->eden_space();
661 SpaceSummary eden_space(eden->bottom(), eden->end(), eden->used_in_bytes());
662
663 MutableSpace* from = young_gen()->from_space();
664 SpaceSummary from_space(from->bottom(), from->end(), from->used_in_bytes());
665
666 MutableSpace* to = young_gen()->to_space();
667 SpaceSummary to_space(to->bottom(), to->end(), to->used_in_bytes());
668
669 VirtualSpaceSummary heap_summary = create_heap_space_summary();
670 return PSHeapSummary(heap_summary, used(), old_summary, old_space, young_summary, eden_space, from_space, to_space);
671 }
672
673 bool ParallelScavengeHeap::print_location(outputStream* st, void* addr) const {
674 return BlockLocationPrinter<ParallelScavengeHeap>::print_location(st, addr);
675 }
676
677 void ParallelScavengeHeap::print_heap_on(outputStream* st) const {
678 if (young_gen() != nullptr) {
679 young_gen()->print_on(st);
680 }
681 if (old_gen() != nullptr) {
682 old_gen()->print_on(st);
683 }
684 }
685
686 void ParallelScavengeHeap::print_gc_on(outputStream* st) const {
687 BarrierSet* bs = BarrierSet::barrier_set();
688 if (bs != nullptr) {
689 bs->print_on(st);
690 }
691 st->cr();
692
693 if (UseCompactObjectHeaders) {
694 PSParallelCompactNew::print_on(st);
695 } else {
696 PSParallelCompact::print_on(st);
697 }
698 }
699
700 void ParallelScavengeHeap::gc_threads_do(ThreadClosure* tc) const {
701 ParallelScavengeHeap::heap()->workers().threads_do(tc);
702 }
703
704 void ParallelScavengeHeap::print_tracing_info() const {
705 AdaptiveSizePolicyOutput::print();
706 log_debug(gc, heap, exit)("Accumulated young generation GC time %3.7f secs", PSScavenge::accumulated_time()->seconds());
707 if (UseCompactObjectHeaders) {
708 log_debug(gc, heap, exit)("Accumulated old generation GC time %3.7f secs", PSParallelCompactNew::accumulated_time()->seconds());
709 } else {
710 log_debug(gc, heap, exit)("Accumulated old generation GC time %3.7f secs", PSParallelCompact::accumulated_time()->seconds());
711 }
712 }
713
714 PreGenGCValues ParallelScavengeHeap::get_pre_gc_values() const {
715 const PSYoungGen* const young = young_gen();
716 const MutableSpace* const eden = young->eden_space();
717 const MutableSpace* const from = young->from_space();
718 const PSOldGen* const old = old_gen();
719
720 return PreGenGCValues(young->used_in_bytes(),
721 young->capacity_in_bytes(),
722 eden->used_in_bytes(),
723 eden->capacity_in_bytes(),
724 from->used_in_bytes(),
725 from->capacity_in_bytes(),
726 old->used_in_bytes(),
727 old->capacity_in_bytes());
728 }
729
730 void ParallelScavengeHeap::print_heap_change(const PreGenGCValues& pre_gc_values) const {
731 const PSYoungGen* const young = young_gen();
732 const MutableSpace* const eden = young->eden_space();
733 const MutableSpace* const from = young->from_space();
734 const PSOldGen* const old = old_gen();
735
736 log_info(gc, heap)(HEAP_CHANGE_FORMAT" "
737 HEAP_CHANGE_FORMAT" "
738 HEAP_CHANGE_FORMAT,
739 HEAP_CHANGE_FORMAT_ARGS(young->name(),
740 pre_gc_values.young_gen_used(),
741 pre_gc_values.young_gen_capacity(),
742 young->used_in_bytes(),
743 young->capacity_in_bytes()),
744 HEAP_CHANGE_FORMAT_ARGS("Eden",
745 pre_gc_values.eden_used(),
746 pre_gc_values.eden_capacity(),
747 eden->used_in_bytes(),
748 eden->capacity_in_bytes()),
749 HEAP_CHANGE_FORMAT_ARGS("From",
750 pre_gc_values.from_used(),
751 pre_gc_values.from_capacity(),
752 from->used_in_bytes(),
753 from->capacity_in_bytes()));
754 log_info(gc, heap)(HEAP_CHANGE_FORMAT,
755 HEAP_CHANGE_FORMAT_ARGS(old->name(),
756 pre_gc_values.old_gen_used(),
757 pre_gc_values.old_gen_capacity(),
758 old->used_in_bytes(),
759 old->capacity_in_bytes()));
760 MetaspaceUtils::print_metaspace_change(pre_gc_values.metaspace_sizes());
761 }
762
763 void ParallelScavengeHeap::verify(VerifyOption option /* ignored */) {
764 // Why do we need the total_collections()-filter below?
765 if (total_collections() > 0) {
766 log_debug(gc, verify)("Tenured");
767 old_gen()->verify();
768
769 log_debug(gc, verify)("Eden");
770 young_gen()->verify();
771
772 log_debug(gc, verify)("CardTable");
773 card_table()->verify_all_young_refs_imprecise();
774 }
775 }
776
777 void ParallelScavengeHeap::trace_actual_reserved_page_size(const size_t reserved_heap_size, const ReservedSpace rs) {
778 // Check if Info level is enabled, since os::trace_page_sizes() logs on Info level.
779 if(log_is_enabled(Info, pagesize)) {
780 const size_t page_size = rs.page_size();
781 os::trace_page_sizes("Heap",
782 MinHeapSize,
783 reserved_heap_size,
784 rs.base(),
785 rs.size(),
786 page_size);
787 }
788 }
789
790 void ParallelScavengeHeap::trace_heap(GCWhen::Type when, const GCTracer* gc_tracer) {
791 const PSHeapSummary& heap_summary = create_ps_heap_summary();
792 gc_tracer->report_gc_heap_summary(when, heap_summary);
793
794 const MetaspaceSummary& metaspace_summary = create_metaspace_summary();
795 gc_tracer->report_metaspace_summary(when, metaspace_summary);
796 }
797
798 CardTableBarrierSet* ParallelScavengeHeap::barrier_set() {
799 return barrier_set_cast<CardTableBarrierSet>(BarrierSet::barrier_set());
800 }
801
802 PSCardTable* ParallelScavengeHeap::card_table() {
803 return static_cast<PSCardTable*>(barrier_set()->card_table());
804 }
805
806 void ParallelScavengeHeap::resize_young_gen(size_t eden_size,
807 size_t survivor_size) {
808 // Delegate the resize to the generation.
809 _young_gen->resize(eden_size, survivor_size);
810 }
811
812 void ParallelScavengeHeap::resize_old_gen(size_t desired_free_space) {
813 // Delegate the resize to the generation.
814 _old_gen->resize(desired_free_space);
815 }
816
817 HeapWord* ParallelScavengeHeap::allocate_loaded_archive_space(size_t size) {
818 return _old_gen->allocate(size);
819 }
820
821 void ParallelScavengeHeap::complete_loaded_archive_space(MemRegion archive_space) {
822 assert(_old_gen->object_space()->used_region().contains(archive_space),
823 "Archive space not contained in old gen");
824 _old_gen->complete_loaded_archive_space(archive_space);
825 }
826
827 void ParallelScavengeHeap::register_nmethod(nmethod* nm) {
828 ScavengableNMethods::register_nmethod(nm);
829 }
830
831 void ParallelScavengeHeap::unregister_nmethod(nmethod* nm) {
832 ScavengableNMethods::unregister_nmethod(nm);
833 }
834
835 void ParallelScavengeHeap::verify_nmethod(nmethod* nm) {
836 ScavengableNMethods::verify_nmethod(nm);
837 }
838
839 GrowableArray<GCMemoryManager*> ParallelScavengeHeap::memory_managers() {
840 GrowableArray<GCMemoryManager*> memory_managers(2);
841 memory_managers.append(_young_manager);
842 memory_managers.append(_old_manager);
843 return memory_managers;
844 }
845
846 GrowableArray<MemoryPool*> ParallelScavengeHeap::memory_pools() {
847 GrowableArray<MemoryPool*> memory_pools(3);
848 memory_pools.append(_eden_pool);
849 memory_pools.append(_survivor_pool);
850 memory_pools.append(_old_pool);
851 return memory_pools;
852 }
853
854 void ParallelScavengeHeap::pin_object(JavaThread* thread, oop obj) {
855 GCLocker::enter(thread);
856 }
857
858 void ParallelScavengeHeap::unpin_object(JavaThread* thread, oop obj) {
859 GCLocker::exit(thread);
860 }
861
862 void ParallelScavengeHeap::update_parallel_worker_threads_cpu_time() {
863 assert(Thread::current()->is_VM_thread(),
864 "Must be called from VM thread to avoid races");
865 if (!UsePerfData || !os::is_thread_cpu_time_supported()) {
866 return;
867 }
868
869 // Ensure ThreadTotalCPUTimeClosure destructor is called before publishing gc
870 // time.
871 {
872 ThreadTotalCPUTimeClosure tttc(CPUTimeGroups::CPUTimeType::gc_parallel_workers);
873 // Currently parallel worker threads in GCTaskManager never terminate, so it
874 // is safe for VMThread to read their CPU times. If upstream changes this
875 // behavior, we should rethink if it is still safe.
876 gc_threads_do(&tttc);
877 }
878
879 CPUTimeCounters::publish_gc_total_cpu_time();
880 }