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, GenAlignment);
74 ReservedSpace young_rs = heap_rs.last_part(MaxOldSize, GenAlignment);
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 "old", 1);
99
100 assert(young_gen()->max_gen_size() == young_rs.size(),"Consistency check");
101 assert(old_gen()->max_gen_size() == old_rs.size(), "Consistency check");
102
103 double max_gc_pause_sec = ((double) MaxGCPauseMillis)/1000.0;
104
105 const size_t eden_capacity = _young_gen->eden_space()->capacity_in_bytes();
106 const size_t old_capacity = _old_gen->capacity_in_bytes();
107 const size_t initial_promo_size = MIN2(eden_capacity, old_capacity);
108 _size_policy =
109 new PSAdaptiveSizePolicy(eden_capacity,
110 initial_promo_size,
111 young_gen()->to_space()->capacity_in_bytes(),
112 GenAlignment,
113 max_gc_pause_sec,
114 GCTimeRatio
115 );
116
117 assert((old_gen()->virtual_space()->high_boundary() ==
118 young_gen()->virtual_space()->low_boundary()),
119 "Boundaries must meet");
120 // initialize the policy counters - 2 collectors, 2 generations
121 _gc_policy_counters =
122 new PSGCAdaptivePolicyCounters("ParScav:MSC", 2, 2, _size_policy);
123
124 if (UseCompactObjectHeaders) {
125 if (!PSParallelCompactNew::initialize_aux_data()) {
126 return JNI_ENOMEM;
127 }
128 } else {
129 if (!PSParallelCompact::initialize_aux_data()) {
130 return JNI_ENOMEM;
131 }
132 }
133
134 // Create CPU time counter
135 CPUTimeCounters::create_counter(CPUTimeGroups::CPUTimeType::gc_parallel_workers);
136
137 ParallelInitLogger::print();
138
139 FullGCForwarding::initialize(_reserved);
140
141 return JNI_OK;
142 }
143
144 void ParallelScavengeHeap::initialize_serviceability() {
145
146 _eden_pool = new EdenMutableSpacePool(_young_gen,
147 _young_gen->eden_space(),
148 "PS Eden Space",
149 false /* support_usage_threshold */);
150
151 _survivor_pool = new SurvivorMutableSpacePool(_young_gen,
152 "PS Survivor Space",
153 false /* support_usage_threshold */);
154
155 _old_pool = new PSGenerationPool(_old_gen,
156 "PS Old Gen",
157 true /* support_usage_threshold */);
158
159 _young_manager = new GCMemoryManager("PS Scavenge");
160 _old_manager = new GCMemoryManager("PS MarkSweep");
161
162 _old_manager->add_pool(_eden_pool);
163 _old_manager->add_pool(_survivor_pool);
164 _old_manager->add_pool(_old_pool);
165
166 _young_manager->add_pool(_eden_pool);
167 _young_manager->add_pool(_survivor_pool);
168
169 }
170
171 void ParallelScavengeHeap::safepoint_synchronize_begin() {
172 if (UseStringDeduplication) {
173 SuspendibleThreadSet::synchronize();
174 }
175 }
176
177 void ParallelScavengeHeap::safepoint_synchronize_end() {
178 if (UseStringDeduplication) {
179 SuspendibleThreadSet::desynchronize();
180 }
181 }
182 class PSIsScavengable : public BoolObjectClosure {
183 bool do_object_b(oop obj) {
184 return ParallelScavengeHeap::heap()->is_in_young(obj);
185 }
186 };
187
188 static PSIsScavengable _is_scavengable;
189
190 void ParallelScavengeHeap::post_initialize() {
191 CollectedHeap::post_initialize();
192 // Need to init the tenuring threshold
193 PSScavenge::initialize();
194 if (UseCompactObjectHeaders) {
195 PSParallelCompactNew::post_initialize();
196 } else {
197 PSParallelCompact::post_initialize();
198 }
199 PSPromotionManager::initialize();
200
201 ScavengableNMethods::initialize(&_is_scavengable);
202 GCLocker::initialize();
203 }
204
205 void ParallelScavengeHeap::update_counters() {
206 young_gen()->update_counters();
207 old_gen()->update_counters();
208 MetaspaceCounters::update_performance_counters();
209 update_parallel_worker_threads_cpu_time();
210 }
211
212 size_t ParallelScavengeHeap::capacity() const {
213 size_t value = young_gen()->capacity_in_bytes() + old_gen()->capacity_in_bytes();
214 return value;
215 }
216
217 size_t ParallelScavengeHeap::used() const {
218 size_t value = young_gen()->used_in_bytes() + old_gen()->used_in_bytes();
219 return value;
220 }
221
222 bool ParallelScavengeHeap::is_maximal_no_gc() const {
223 // We don't expand young-gen except at a GC.
224 return old_gen()->is_maximal_no_gc();
225 }
226
227
228 size_t ParallelScavengeHeap::max_capacity() const {
229 size_t estimated = reserved_region().byte_size();
230 if (UseAdaptiveSizePolicy) {
231 estimated -= _size_policy->max_survivor_size(young_gen()->max_gen_size());
232 } else {
233 estimated -= young_gen()->to_space()->capacity_in_bytes();
234 }
235 return MAX2(estimated, capacity());
236 }
237
238 bool ParallelScavengeHeap::is_in(const void* p) const {
239 return young_gen()->is_in(p) || old_gen()->is_in(p);
240 }
241
242 bool ParallelScavengeHeap::is_in_reserved(const void* p) const {
243 return young_gen()->is_in_reserved(p) || old_gen()->is_in_reserved(p);
244 }
245
246 bool ParallelScavengeHeap::requires_barriers(stackChunkOop p) const {
247 return !is_in_young(p);
248 }
249
250 // There are two levels of allocation policy here.
251 //
252 // When an allocation request fails, the requesting thread must invoke a VM
253 // operation, transfer control to the VM thread, and await the results of a
254 // garbage collection. That is quite expensive, and we should avoid doing it
255 // multiple times if possible.
256 //
257 // To accomplish this, we have a basic allocation policy, and also a
258 // failed allocation policy.
259 //
260 // The basic allocation policy controls how you allocate memory without
261 // attempting garbage collection. It is okay to grab locks and
262 // expand the heap, if that can be done without coming to a safepoint.
263 // It is likely that the basic allocation policy will not be very
264 // aggressive.
265 //
266 // The failed allocation policy is invoked from the VM thread after
267 // the basic allocation policy is unable to satisfy a mem_allocate
268 // request. This policy needs to cover the entire range of collection,
269 // heap expansion, and out-of-memory conditions. It should make every
270 // attempt to allocate the requested memory.
271
272 // Basic allocation policy. Should never be called at a safepoint, or
273 // from the VM thread.
274 //
275 // This method must handle cases where many mem_allocate requests fail
276 // simultaneously. When that happens, only one VM operation will succeed,
277 // and the rest will not be executed. For that reason, this method loops
278 // during failed allocation attempts. If the java heap becomes exhausted,
279 // we rely on the size_policy object to force a bail out.
280 HeapWord* ParallelScavengeHeap::mem_allocate(size_t size,
281 bool* gc_overhead_limit_was_exceeded) {
282 assert(!SafepointSynchronize::is_at_safepoint(), "should not be at safepoint");
283 assert(Thread::current() != (Thread*)VMThread::vm_thread(), "should not be in vm thread");
284 assert(!Heap_lock->owned_by_self(), "this thread should not own the Heap_lock");
285
286 bool is_tlab = false;
287 return mem_allocate_work(size, is_tlab, gc_overhead_limit_was_exceeded);
288 }
289
290 HeapWord* ParallelScavengeHeap::mem_allocate_work(size_t size,
291 bool is_tlab,
292 bool* gc_overhead_limit_was_exceeded) {
293
294 // In general gc_overhead_limit_was_exceeded should be false so
295 // set it so here and reset it to true only if the gc time
296 // limit is being exceeded as checked below.
297 *gc_overhead_limit_was_exceeded = false;
298
299 HeapWord* result = young_gen()->allocate(size);
300
301 uint loop_count = 0;
302 uint gc_count = 0;
303
304 while (result == nullptr) {
305 // We don't want to have multiple collections for a single filled generation.
306 // To prevent this, each thread tracks the total_collections() value, and if
307 // the count has changed, does not do a new collection.
308 //
309 // The collection count must be read only while holding the heap lock. VM
310 // operations also hold the heap lock during collections. There is a lock
311 // contention case where thread A blocks waiting on the Heap_lock, while
312 // thread B is holding it doing a collection. When thread A gets the lock,
313 // the collection count has already changed. To prevent duplicate collections,
314 // The policy MUST attempt allocations during the same period it reads the
315 // total_collections() value!
316 {
317 MutexLocker ml(Heap_lock);
318 gc_count = total_collections();
319
320 result = young_gen()->allocate(size);
321 if (result != nullptr) {
322 return result;
323 }
324
325 // If certain conditions hold, try allocating from the old gen.
326 if (!is_tlab) {
327 result = mem_allocate_old_gen(size);
328 if (result != nullptr) {
329 return result;
330 }
331 }
332 }
333
334 assert(result == nullptr, "inv");
335 {
336 VM_ParallelCollectForAllocation op(size, is_tlab, gc_count);
337 VMThread::execute(&op);
338
339 // Did the VM operation execute? If so, return the result directly.
340 // This prevents us from looping until time out on requests that can
341 // not be satisfied.
342 if (op.prologue_succeeded()) {
343 assert(is_in_or_null(op.result()), "result not in heap");
344
345 // Exit the loop if the gc time limit has been exceeded.
346 // The allocation must have failed above ("result" guarding
347 // this path is null) and the most recent collection has exceeded the
348 // gc overhead limit (although enough may have been collected to
349 // satisfy the allocation). Exit the loop so that an out-of-memory
350 // will be thrown (return a null ignoring the contents of
351 // op.result()),
352 // but clear gc_overhead_limit_exceeded so that the next collection
353 // starts with a clean slate (i.e., forgets about previous overhead
354 // excesses). Fill op.result() with a filler object so that the
355 // heap remains parsable.
356 const bool limit_exceeded = size_policy()->gc_overhead_limit_exceeded();
357 const bool softrefs_clear = soft_ref_policy()->all_soft_refs_clear();
358
359 if (limit_exceeded && softrefs_clear) {
360 *gc_overhead_limit_was_exceeded = true;
361 size_policy()->set_gc_overhead_limit_exceeded(false);
362 log_trace(gc)("ParallelScavengeHeap::mem_allocate: return null because gc_overhead_limit_exceeded is set");
363 if (op.result() != nullptr) {
364 CollectedHeap::fill_with_object(op.result(), size);
365 }
366 return nullptr;
367 }
368
369 return op.result();
370 }
371 }
372
373 // The policy object will prevent us from looping forever. If the
374 // time spent in gc crosses a threshold, we will bail out.
375 loop_count++;
376 if ((result == nullptr) && (QueuedAllocationWarningCount > 0) &&
377 (loop_count % QueuedAllocationWarningCount == 0)) {
378 log_warning(gc)("ParallelScavengeHeap::mem_allocate retries %d times", loop_count);
379 log_warning(gc)("\tsize=%zu", size);
380 }
381 }
382
383 return result;
384 }
385
386 HeapWord* ParallelScavengeHeap::allocate_old_gen_and_record(size_t size) {
387 assert_locked_or_safepoint(Heap_lock);
388 HeapWord* res = old_gen()->allocate(size);
389 if (res != nullptr) {
390 _size_policy->tenured_allocation(size * HeapWordSize);
391 }
392 return res;
393 }
394
395 HeapWord* ParallelScavengeHeap::mem_allocate_old_gen(size_t size) {
396 if (!should_alloc_in_eden(size)) {
397 // Size is too big for eden.
398 return allocate_old_gen_and_record(size);
399 }
400
401 return nullptr;
402 }
403
404 void ParallelScavengeHeap::do_full_collection(bool clear_all_soft_refs) {
405 if (UseCompactObjectHeaders) {
406 PSParallelCompactNew::invoke(clear_all_soft_refs, false /* serial */);
407 } else {
408 PSParallelCompact::invoke(clear_all_soft_refs);
409 }
410 }
411
412 HeapWord* ParallelScavengeHeap::expand_heap_and_allocate(size_t size, bool is_tlab) {
413 HeapWord* result = nullptr;
414
415 result = young_gen()->allocate(size);
416 if (result == nullptr && !is_tlab) {
417 result = old_gen()->expand_and_allocate(size);
418 }
419 return result; // Could be null if we are out of space.
420 }
421
422 HeapWord* ParallelScavengeHeap::satisfy_failed_allocation(size_t size, bool is_tlab) {
423 assert(size != 0, "precondition");
424
425 HeapWord* result = nullptr;
426
427 // If young-gen can handle this allocation, attempt young-gc firstly.
428 bool should_run_young_gc = is_tlab || should_alloc_in_eden(size);
429 collect_at_safepoint(!should_run_young_gc);
430
431 result = expand_heap_and_allocate(size, is_tlab);
432 if (result != nullptr) {
433 return result;
434 }
435
436 // If we reach this point, we're really out of memory. Try every trick
437 // we can to reclaim memory. Force collection of soft references. Force
438 // a complete compaction of the heap. Any additional methods for finding
439 // free memory should be here, especially if they are expensive. If this
440 // attempt fails, an OOM exception will be thrown.
441 {
442 // Make sure the heap is fully compacted
443 uintx old_interval = HeapMaximumCompactionInterval;
444 HeapMaximumCompactionInterval = 0;
445
446 const bool clear_all_soft_refs = true;
447 if (UseCompactObjectHeaders) {
448 PSParallelCompactNew::invoke(clear_all_soft_refs, false /* serial */);
449 } else {
450 PSParallelCompact::invoke(clear_all_soft_refs);
451 }
452
453 // Restore
454 HeapMaximumCompactionInterval = old_interval;
455 }
456
457 result = expand_heap_and_allocate(size, is_tlab);
458 if (result != nullptr) {
459 return result;
460 }
461
462 if (UseCompactObjectHeaders) {
463 PSParallelCompactNew::invoke(true /* clear_soft_refs */, true /* serial */);
464 }
465
466 result = expand_heap_and_allocate(size, is_tlab);
467 if (result != nullptr) {
468 return result;
469 }
470
471 // What else? We might try synchronous finalization later. If the total
472 // space available is large enough for the allocation, then a more
473 // complete compaction phase than we've tried so far might be
474 // appropriate.
475 return nullptr;
476 }
477
478
479 void ParallelScavengeHeap::ensure_parsability(bool retire_tlabs) {
480 CollectedHeap::ensure_parsability(retire_tlabs);
481 young_gen()->eden_space()->ensure_parsability();
482 }
483
484 size_t ParallelScavengeHeap::tlab_capacity(Thread* thr) const {
485 return young_gen()->eden_space()->tlab_capacity(thr);
486 }
487
488 size_t ParallelScavengeHeap::tlab_used(Thread* thr) const {
489 return young_gen()->eden_space()->tlab_used(thr);
490 }
491
492 size_t ParallelScavengeHeap::unsafe_max_tlab_alloc(Thread* thr) const {
493 return young_gen()->eden_space()->unsafe_max_tlab_alloc(thr);
494 }
495
496 HeapWord* ParallelScavengeHeap::allocate_new_tlab(size_t min_size, size_t requested_size, size_t* actual_size) {
497 bool dummy;
498 HeapWord* result = mem_allocate_work(requested_size /* size */,
499 true /* is_tlab */,
500 &dummy);
501 if (result != nullptr) {
502 *actual_size = requested_size;
503 }
504
505 return result;
506 }
507
508 void ParallelScavengeHeap::resize_all_tlabs() {
509 CollectedHeap::resize_all_tlabs();
510 }
511
512 void ParallelScavengeHeap::prune_scavengable_nmethods() {
513 ScavengableNMethods::prune_nmethods_not_into_young();
514 }
515
516 void ParallelScavengeHeap::prune_unlinked_nmethods() {
517 ScavengableNMethods::prune_unlinked_nmethods();
518 }
519
520 void ParallelScavengeHeap::collect(GCCause::Cause cause) {
521 assert(!Heap_lock->owned_by_self(),
522 "this thread should not own the Heap_lock");
523
524 uint gc_count = 0;
525 uint full_gc_count = 0;
526 {
527 MutexLocker ml(Heap_lock);
528 // This value is guarded by the Heap_lock
529 gc_count = total_collections();
530 full_gc_count = total_full_collections();
531 }
532
533 while (true) {
534 VM_ParallelGCCollect op(gc_count, full_gc_count, cause);
535 VMThread::execute(&op);
536
537 if (!GCCause::is_explicit_full_gc(cause)) {
538 return;
539 }
540
541 {
542 MutexLocker ml(Heap_lock);
543 if (full_gc_count != total_full_collections()) {
544 return;
545 }
546 }
547 }
548 }
549
550 bool ParallelScavengeHeap::must_clear_all_soft_refs() {
551 return _gc_cause == GCCause::_metadata_GC_clear_soft_refs ||
552 _gc_cause == GCCause::_wb_full_gc;
553 }
554
555 void ParallelScavengeHeap::collect_at_safepoint(bool full) {
556 assert(!GCLocker::is_active(), "precondition");
557 bool clear_soft_refs = must_clear_all_soft_refs();
558
559 if (!full) {
560 bool success = PSScavenge::invoke(clear_soft_refs);
561 if (success) {
562 return;
563 }
564 // Upgrade to Full-GC if young-gc fails
565 }
566 if (UseCompactObjectHeaders) {
567 PSParallelCompactNew::invoke(clear_soft_refs, false /* serial */);
568 } else {
569 PSParallelCompact::invoke(clear_soft_refs);
570 }
571 }
572
573 void ParallelScavengeHeap::object_iterate(ObjectClosure* cl) {
574 young_gen()->object_iterate(cl);
575 old_gen()->object_iterate(cl);
576 }
577
578 // The HeapBlockClaimer is used during parallel iteration over the heap,
579 // allowing workers to claim heap areas ("blocks"), gaining exclusive rights to these.
580 // The eden and survivor spaces are treated as single blocks as it is hard to divide
581 // these spaces.
582 // The old space is divided into fixed-size blocks.
583 class HeapBlockClaimer : public StackObj {
584 size_t _claimed_index;
585
586 public:
587 static const size_t InvalidIndex = SIZE_MAX;
588 static const size_t EdenIndex = 0;
589 static const size_t SurvivorIndex = 1;
590 static const size_t NumNonOldGenClaims = 2;
591
592 HeapBlockClaimer() : _claimed_index(EdenIndex) { }
593 // Claim the block and get the block index.
594 size_t claim_and_get_block() {
595 size_t block_index;
596 block_index = Atomic::fetch_then_add(&_claimed_index, 1u);
597
598 PSOldGen* old_gen = ParallelScavengeHeap::heap()->old_gen();
599 size_t num_claims = old_gen->num_iterable_blocks() + NumNonOldGenClaims;
600
601 return block_index < num_claims ? block_index : InvalidIndex;
602 }
603 };
604
605 void ParallelScavengeHeap::object_iterate_parallel(ObjectClosure* cl,
606 HeapBlockClaimer* claimer) {
607 size_t block_index = claimer->claim_and_get_block();
608 // Iterate until all blocks are claimed
609 if (block_index == HeapBlockClaimer::EdenIndex) {
610 young_gen()->eden_space()->object_iterate(cl);
611 block_index = claimer->claim_and_get_block();
612 }
613 if (block_index == HeapBlockClaimer::SurvivorIndex) {
614 young_gen()->from_space()->object_iterate(cl);
615 young_gen()->to_space()->object_iterate(cl);
616 block_index = claimer->claim_and_get_block();
617 }
618 while (block_index != HeapBlockClaimer::InvalidIndex) {
619 old_gen()->object_iterate_block(cl, block_index - HeapBlockClaimer::NumNonOldGenClaims);
620 block_index = claimer->claim_and_get_block();
621 }
622 }
623
624 class PSScavengeParallelObjectIterator : public ParallelObjectIteratorImpl {
625 private:
626 ParallelScavengeHeap* _heap;
627 HeapBlockClaimer _claimer;
628
629 public:
630 PSScavengeParallelObjectIterator() :
631 _heap(ParallelScavengeHeap::heap()),
632 _claimer() {}
633
634 virtual void object_iterate(ObjectClosure* cl, uint worker_id) {
635 _heap->object_iterate_parallel(cl, &_claimer);
636 }
637 };
638
639 ParallelObjectIteratorImpl* ParallelScavengeHeap::parallel_object_iterator(uint thread_num) {
640 return new PSScavengeParallelObjectIterator();
641 }
642
643 HeapWord* ParallelScavengeHeap::block_start(const void* addr) const {
644 if (young_gen()->is_in_reserved(addr)) {
645 assert(young_gen()->is_in(addr),
646 "addr should be in allocated part of young gen");
647 // called from os::print_location by find or VMError
648 if (DebuggingContext::is_enabled() || VMError::is_error_reported()) {
649 return nullptr;
650 }
651 Unimplemented();
652 } else if (old_gen()->is_in_reserved(addr)) {
653 assert(old_gen()->is_in(addr),
654 "addr should be in allocated part of old gen");
655 return old_gen()->start_array()->object_start((HeapWord*)addr);
656 }
657 return nullptr;
658 }
659
660 bool ParallelScavengeHeap::block_is_obj(const HeapWord* addr) const {
661 return block_start(addr) == addr;
662 }
663
664 void ParallelScavengeHeap::prepare_for_verify() {
665 ensure_parsability(false); // no need to retire TLABs for verification
666 }
667
668 PSHeapSummary ParallelScavengeHeap::create_ps_heap_summary() {
669 PSOldGen* old = old_gen();
670 HeapWord* old_committed_end = (HeapWord*)old->virtual_space()->committed_high_addr();
671 HeapWord* old_reserved_start = old->reserved().start();
672 HeapWord* old_reserved_end = old->reserved().end();
673 VirtualSpaceSummary old_summary(old_reserved_start, old_committed_end, old_reserved_end);
674 SpaceSummary old_space(old_reserved_start, old_committed_end, old->used_in_bytes());
675
676 PSYoungGen* young = young_gen();
677 VirtualSpaceSummary young_summary(young->reserved().start(),
678 (HeapWord*)young->virtual_space()->committed_high_addr(), young->reserved().end());
679
680 MutableSpace* eden = young_gen()->eden_space();
681 SpaceSummary eden_space(eden->bottom(), eden->end(), eden->used_in_bytes());
682
683 MutableSpace* from = young_gen()->from_space();
684 SpaceSummary from_space(from->bottom(), from->end(), from->used_in_bytes());
685
686 MutableSpace* to = young_gen()->to_space();
687 SpaceSummary to_space(to->bottom(), to->end(), to->used_in_bytes());
688
689 VirtualSpaceSummary heap_summary = create_heap_space_summary();
690 return PSHeapSummary(heap_summary, used(), old_summary, old_space, young_summary, eden_space, from_space, to_space);
691 }
692
693 bool ParallelScavengeHeap::print_location(outputStream* st, void* addr) const {
694 return BlockLocationPrinter<ParallelScavengeHeap>::print_location(st, addr);
695 }
696
697 void ParallelScavengeHeap::print_on(outputStream* st) const {
698 if (young_gen() != nullptr) {
699 young_gen()->print_on(st);
700 }
701 if (old_gen() != nullptr) {
702 old_gen()->print_on(st);
703 }
704 MetaspaceUtils::print_on(st);
705 }
706
707 void ParallelScavengeHeap::print_on_error(outputStream* st) const {
708 this->CollectedHeap::print_on_error(st);
709
710 st->cr();
711 if (UseCompactObjectHeaders) {
712 PSParallelCompactNew::print_on_error(st);
713 } else {
714 PSParallelCompact::print_on_error(st);
715 }
716 }
717
718 void ParallelScavengeHeap::gc_threads_do(ThreadClosure* tc) const {
719 ParallelScavengeHeap::heap()->workers().threads_do(tc);
720 }
721
722 void ParallelScavengeHeap::print_tracing_info() const {
723 AdaptiveSizePolicyOutput::print();
724 log_debug(gc, heap, exit)("Accumulated young generation GC time %3.7f secs", PSScavenge::accumulated_time()->seconds());
725 if (UseCompactObjectHeaders) {
726 log_debug(gc, heap, exit)("Accumulated old generation GC time %3.7f secs", PSParallelCompactNew::accumulated_time()->seconds());
727 } else {
728 log_debug(gc, heap, exit)("Accumulated old generation GC time %3.7f secs", PSParallelCompact::accumulated_time()->seconds());
729 }
730 }
731
732 PreGenGCValues ParallelScavengeHeap::get_pre_gc_values() const {
733 const PSYoungGen* const young = young_gen();
734 const MutableSpace* const eden = young->eden_space();
735 const MutableSpace* const from = young->from_space();
736 const PSOldGen* const old = old_gen();
737
738 return PreGenGCValues(young->used_in_bytes(),
739 young->capacity_in_bytes(),
740 eden->used_in_bytes(),
741 eden->capacity_in_bytes(),
742 from->used_in_bytes(),
743 from->capacity_in_bytes(),
744 old->used_in_bytes(),
745 old->capacity_in_bytes());
746 }
747
748 void ParallelScavengeHeap::print_heap_change(const PreGenGCValues& pre_gc_values) const {
749 const PSYoungGen* const young = young_gen();
750 const MutableSpace* const eden = young->eden_space();
751 const MutableSpace* const from = young->from_space();
752 const PSOldGen* const old = old_gen();
753
754 log_info(gc, heap)(HEAP_CHANGE_FORMAT" "
755 HEAP_CHANGE_FORMAT" "
756 HEAP_CHANGE_FORMAT,
757 HEAP_CHANGE_FORMAT_ARGS(young->name(),
758 pre_gc_values.young_gen_used(),
759 pre_gc_values.young_gen_capacity(),
760 young->used_in_bytes(),
761 young->capacity_in_bytes()),
762 HEAP_CHANGE_FORMAT_ARGS("Eden",
763 pre_gc_values.eden_used(),
764 pre_gc_values.eden_capacity(),
765 eden->used_in_bytes(),
766 eden->capacity_in_bytes()),
767 HEAP_CHANGE_FORMAT_ARGS("From",
768 pre_gc_values.from_used(),
769 pre_gc_values.from_capacity(),
770 from->used_in_bytes(),
771 from->capacity_in_bytes()));
772 log_info(gc, heap)(HEAP_CHANGE_FORMAT,
773 HEAP_CHANGE_FORMAT_ARGS(old->name(),
774 pre_gc_values.old_gen_used(),
775 pre_gc_values.old_gen_capacity(),
776 old->used_in_bytes(),
777 old->capacity_in_bytes()));
778 MetaspaceUtils::print_metaspace_change(pre_gc_values.metaspace_sizes());
779 }
780
781 void ParallelScavengeHeap::verify(VerifyOption option /* ignored */) {
782 // Why do we need the total_collections()-filter below?
783 if (total_collections() > 0) {
784 log_debug(gc, verify)("Tenured");
785 old_gen()->verify();
786
787 log_debug(gc, verify)("Eden");
788 young_gen()->verify();
789
790 log_debug(gc, verify)("CardTable");
791 card_table()->verify_all_young_refs_imprecise();
792 }
793 }
794
795 void ParallelScavengeHeap::trace_actual_reserved_page_size(const size_t reserved_heap_size, const ReservedSpace rs) {
796 // Check if Info level is enabled, since os::trace_page_sizes() logs on Info level.
797 if(log_is_enabled(Info, pagesize)) {
798 const size_t page_size = rs.page_size();
799 os::trace_page_sizes("Heap",
800 MinHeapSize,
801 reserved_heap_size,
802 rs.base(),
803 rs.size(),
804 page_size);
805 }
806 }
807
808 void ParallelScavengeHeap::trace_heap(GCWhen::Type when, const GCTracer* gc_tracer) {
809 const PSHeapSummary& heap_summary = create_ps_heap_summary();
810 gc_tracer->report_gc_heap_summary(when, heap_summary);
811
812 const MetaspaceSummary& metaspace_summary = create_metaspace_summary();
813 gc_tracer->report_metaspace_summary(when, metaspace_summary);
814 }
815
816 CardTableBarrierSet* ParallelScavengeHeap::barrier_set() {
817 return barrier_set_cast<CardTableBarrierSet>(BarrierSet::barrier_set());
818 }
819
820 PSCardTable* ParallelScavengeHeap::card_table() {
821 return static_cast<PSCardTable*>(barrier_set()->card_table());
822 }
823
824 void ParallelScavengeHeap::resize_young_gen(size_t eden_size,
825 size_t survivor_size) {
826 // Delegate the resize to the generation.
827 _young_gen->resize(eden_size, survivor_size);
828 }
829
830 void ParallelScavengeHeap::resize_old_gen(size_t desired_free_space) {
831 // Delegate the resize to the generation.
832 _old_gen->resize(desired_free_space);
833 }
834
835 HeapWord* ParallelScavengeHeap::allocate_loaded_archive_space(size_t size) {
836 return _old_gen->allocate(size);
837 }
838
839 void ParallelScavengeHeap::complete_loaded_archive_space(MemRegion archive_space) {
840 assert(_old_gen->object_space()->used_region().contains(archive_space),
841 "Archive space not contained in old gen");
842 _old_gen->complete_loaded_archive_space(archive_space);
843 }
844
845 void ParallelScavengeHeap::register_nmethod(nmethod* nm) {
846 ScavengableNMethods::register_nmethod(nm);
847 }
848
849 void ParallelScavengeHeap::unregister_nmethod(nmethod* nm) {
850 ScavengableNMethods::unregister_nmethod(nm);
851 }
852
853 void ParallelScavengeHeap::verify_nmethod(nmethod* nm) {
854 ScavengableNMethods::verify_nmethod(nm);
855 }
856
857 GrowableArray<GCMemoryManager*> ParallelScavengeHeap::memory_managers() {
858 GrowableArray<GCMemoryManager*> memory_managers(2);
859 memory_managers.append(_young_manager);
860 memory_managers.append(_old_manager);
861 return memory_managers;
862 }
863
864 GrowableArray<MemoryPool*> ParallelScavengeHeap::memory_pools() {
865 GrowableArray<MemoryPool*> memory_pools(3);
866 memory_pools.append(_eden_pool);
867 memory_pools.append(_survivor_pool);
868 memory_pools.append(_old_pool);
869 return memory_pools;
870 }
871
872 void ParallelScavengeHeap::pin_object(JavaThread* thread, oop obj) {
873 GCLocker::enter(thread);
874 }
875
876 void ParallelScavengeHeap::unpin_object(JavaThread* thread, oop obj) {
877 GCLocker::exit(thread);
878 }
879
880 void ParallelScavengeHeap::update_parallel_worker_threads_cpu_time() {
881 assert(Thread::current()->is_VM_thread(),
882 "Must be called from VM thread to avoid races");
883 if (!UsePerfData || !os::is_thread_cpu_time_supported()) {
884 return;
885 }
886
887 // Ensure ThreadTotalCPUTimeClosure destructor is called before publishing gc
888 // time.
889 {
890 ThreadTotalCPUTimeClosure tttc(CPUTimeGroups::CPUTimeType::gc_parallel_workers);
891 // Currently parallel worker threads in GCTaskManager never terminate, so it
892 // is safe for VMThread to read their CPU times. If upstream changes this
893 // behavior, we should rethink if it is still safe.
894 gc_threads_do(&tttc);
895 }
896
897 CPUTimeCounters::publish_gc_total_cpu_time();
898 }