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