1 /*
2 * Copyright (c) 2001, 2024, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "gc/parallel/objectStartArray.inline.hpp"
27 #include "gc/parallel/parallelArguments.hpp"
28 #include "gc/parallel/parallelInitLogger.hpp"
29 #include "gc/parallel/parallelScavengeHeap.inline.hpp"
30 #include "gc/parallel/psAdaptiveSizePolicy.hpp"
31 #include "gc/parallel/psMemoryPool.hpp"
32 #include "gc/parallel/psParallelCompact.inline.hpp"
33 #include "gc/parallel/psPromotionManager.hpp"
34 #include "gc/parallel/psScavenge.hpp"
35 #include "gc/parallel/psVMOperations.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/universe.hpp"
48 #include "nmt/memTracker.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);
73 ReservedSpace young_rs = heap_rs.last_part(MaxOldSize);
74 assert(young_rs.size() == MaxNewSize, "Didn't reserve all of the heap");
75
76 PSCardTable* card_table = new PSCardTable(heap_rs.region());
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 return JNI_OK;
133 }
134
135 void ParallelScavengeHeap::initialize_serviceability() {
136
137 _eden_pool = new EdenMutableSpacePool(_young_gen,
138 _young_gen->eden_space(),
139 "PS Eden Space",
140 false /* support_usage_threshold */);
141
142 _survivor_pool = new SurvivorMutableSpacePool(_young_gen,
143 "PS Survivor Space",
144 false /* support_usage_threshold */);
145
146 _old_pool = new PSGenerationPool(_old_gen,
147 "PS Old Gen",
148 true /* support_usage_threshold */);
149
150 _young_manager = new GCMemoryManager("PS Scavenge");
151 _old_manager = new GCMemoryManager("PS MarkSweep");
152
153 _old_manager->add_pool(_eden_pool);
154 _old_manager->add_pool(_survivor_pool);
155 _old_manager->add_pool(_old_pool);
156
157 _young_manager->add_pool(_eden_pool);
158 _young_manager->add_pool(_survivor_pool);
159
160 }
161
162 void ParallelScavengeHeap::safepoint_synchronize_begin() {
163 if (UseStringDeduplication) {
164 SuspendibleThreadSet::synchronize();
165 }
166 }
167
168 void ParallelScavengeHeap::safepoint_synchronize_end() {
169 if (UseStringDeduplication) {
170 SuspendibleThreadSet::desynchronize();
171 }
172 }
173 class PSIsScavengable : public BoolObjectClosure {
174 bool do_object_b(oop obj) {
175 return ParallelScavengeHeap::heap()->is_in_young(obj);
176 }
177 };
178
179 static PSIsScavengable _is_scavengable;
180
181 void ParallelScavengeHeap::post_initialize() {
182 CollectedHeap::post_initialize();
183 // Need to init the tenuring threshold
184 PSScavenge::initialize();
185 PSParallelCompact::post_initialize();
186 PSPromotionManager::initialize();
187
188 ScavengableNMethods::initialize(&_is_scavengable);
189 }
190
191 void ParallelScavengeHeap::update_counters() {
192 young_gen()->update_counters();
193 old_gen()->update_counters();
194 MetaspaceCounters::update_performance_counters();
195 update_parallel_worker_threads_cpu_time();
196 }
197
198 size_t ParallelScavengeHeap::capacity() const {
199 size_t value = young_gen()->capacity_in_bytes() + old_gen()->capacity_in_bytes();
200 return value;
201 }
202
203 size_t ParallelScavengeHeap::used() const {
204 size_t value = young_gen()->used_in_bytes() + old_gen()->used_in_bytes();
205 return value;
206 }
207
208 bool ParallelScavengeHeap::is_maximal_no_gc() const {
209 // We don't expand young-gen except at a GC.
210 return old_gen()->is_maximal_no_gc();
211 }
212
213
214 size_t ParallelScavengeHeap::max_capacity() const {
215 size_t estimated = reserved_region().byte_size();
216 if (UseAdaptiveSizePolicy) {
217 estimated -= _size_policy->max_survivor_size(young_gen()->max_gen_size());
218 } else {
219 estimated -= young_gen()->to_space()->capacity_in_bytes();
220 }
221 return MAX2(estimated, capacity());
222 }
223
224 bool ParallelScavengeHeap::is_in(const void* p) const {
225 return young_gen()->is_in(p) || old_gen()->is_in(p);
226 }
227
228 bool ParallelScavengeHeap::is_in_reserved(const void* p) const {
229 return young_gen()->is_in_reserved(p) || old_gen()->is_in_reserved(p);
230 }
231
232 bool ParallelScavengeHeap::requires_barriers(stackChunkOop p) const {
233 return !is_in_young(p);
234 }
235
236 // There are two levels of allocation policy here.
237 //
238 // When an allocation request fails, the requesting thread must invoke a VM
239 // operation, transfer control to the VM thread, and await the results of a
240 // garbage collection. That is quite expensive, and we should avoid doing it
241 // multiple times if possible.
242 //
243 // To accomplish this, we have a basic allocation policy, and also a
244 // failed allocation policy.
245 //
246 // The basic allocation policy controls how you allocate memory without
247 // attempting garbage collection. It is okay to grab locks and
248 // expand the heap, if that can be done without coming to a safepoint.
249 // It is likely that the basic allocation policy will not be very
250 // aggressive.
251 //
252 // The failed allocation policy is invoked from the VM thread after
253 // the basic allocation policy is unable to satisfy a mem_allocate
254 // request. This policy needs to cover the entire range of collection,
255 // heap expansion, and out-of-memory conditions. It should make every
256 // attempt to allocate the requested memory.
257
258 // Basic allocation policy. Should never be called at a safepoint, or
259 // from the VM thread.
260 //
261 // This method must handle cases where many mem_allocate requests fail
262 // simultaneously. When that happens, only one VM operation will succeed,
263 // and the rest will not be executed. For that reason, this method loops
264 // during failed allocation attempts. If the java heap becomes exhausted,
265 // we rely on the size_policy object to force a bail out.
266 HeapWord* ParallelScavengeHeap::mem_allocate(
267 size_t size,
268 bool* gc_overhead_limit_was_exceeded) {
269 assert(!SafepointSynchronize::is_at_safepoint(), "should not be at safepoint");
270 assert(Thread::current() != (Thread*)VMThread::vm_thread(), "should not be in vm thread");
271 assert(!Heap_lock->owned_by_self(), "this thread should not own the Heap_lock");
272
273 // In general gc_overhead_limit_was_exceeded should be false so
274 // set it so here and reset it to true only if the gc time
275 // limit is being exceeded as checked below.
276 *gc_overhead_limit_was_exceeded = false;
277
278 HeapWord* result = young_gen()->allocate(size);
279
280 uint loop_count = 0;
281 uint gc_count = 0;
282 uint gclocker_stalled_count = 0;
283
284 while (result == nullptr) {
285 // We don't want to have multiple collections for a single filled generation.
286 // To prevent this, each thread tracks the total_collections() value, and if
287 // the count has changed, does not do a new collection.
288 //
289 // The collection count must be read only while holding the heap lock. VM
290 // operations also hold the heap lock during collections. There is a lock
291 // contention case where thread A blocks waiting on the Heap_lock, while
292 // thread B is holding it doing a collection. When thread A gets the lock,
293 // the collection count has already changed. To prevent duplicate collections,
294 // The policy MUST attempt allocations during the same period it reads the
295 // total_collections() value!
296 {
297 MutexLocker ml(Heap_lock);
298 gc_count = total_collections();
299
300 result = young_gen()->allocate(size);
301 if (result != nullptr) {
302 return result;
303 }
304
305 // If certain conditions hold, try allocating from the old gen.
306 result = mem_allocate_old_gen(size);
307 if (result != nullptr) {
308 return result;
309 }
310
311 if (gclocker_stalled_count > GCLockerRetryAllocationCount) {
312 return nullptr;
313 }
314
315 // Failed to allocate without a gc.
316 if (GCLocker::is_active_and_needs_gc()) {
317 // If this thread is not in a jni critical section, we stall
318 // the requestor until the critical section has cleared and
319 // GC allowed. When the critical section clears, a GC is
320 // initiated by the last thread exiting the critical section; so
321 // we retry the allocation sequence from the beginning of the loop,
322 // rather than causing more, now probably unnecessary, GC attempts.
323 JavaThread* jthr = JavaThread::current();
324 if (!jthr->in_critical()) {
325 MutexUnlocker mul(Heap_lock);
326 GCLocker::stall_until_clear();
327 gclocker_stalled_count += 1;
328 continue;
329 } else {
330 if (CheckJNICalls) {
331 fatal("Possible deadlock due to allocating while"
332 " in jni critical section");
333 }
334 return nullptr;
335 }
336 }
337 }
338
339 if (result == nullptr) {
340 // Generate a VM operation
341 VM_ParallelGCFailedAllocation op(size, gc_count);
342 VMThread::execute(&op);
343
344 // Did the VM operation execute? If so, return the result directly.
345 // This prevents us from looping until time out on requests that can
346 // not be satisfied.
347 if (op.prologue_succeeded()) {
348 assert(is_in_or_null(op.result()), "result not in heap");
349
350 // If GC was locked out during VM operation then retry allocation
351 // and/or stall as necessary.
352 if (op.gc_locked()) {
353 assert(op.result() == nullptr, "must be null if gc_locked() is true");
354 continue; // retry and/or stall as necessary
355 }
356
357 // Exit the loop if the gc time limit has been exceeded.
358 // The allocation must have failed above ("result" guarding
359 // this path is null) and the most recent collection has exceeded the
360 // gc overhead limit (although enough may have been collected to
361 // satisfy the allocation). Exit the loop so that an out-of-memory
362 // will be thrown (return a null ignoring the contents of
363 // op.result()),
364 // but clear gc_overhead_limit_exceeded so that the next collection
365 // starts with a clean slate (i.e., forgets about previous overhead
366 // excesses). Fill op.result() with a filler object so that the
367 // heap remains parsable.
368 const bool limit_exceeded = size_policy()->gc_overhead_limit_exceeded();
369 const bool softrefs_clear = soft_ref_policy()->all_soft_refs_clear();
370
371 if (limit_exceeded && softrefs_clear) {
372 *gc_overhead_limit_was_exceeded = true;
373 size_policy()->set_gc_overhead_limit_exceeded(false);
374 log_trace(gc)("ParallelScavengeHeap::mem_allocate: return null because gc_overhead_limit_exceeded is set");
375 if (op.result() != nullptr) {
376 CollectedHeap::fill_with_object(op.result(), size);
377 }
378 return nullptr;
379 }
380
381 return op.result();
382 }
383 }
384
385 // The policy object will prevent us from looping forever. If the
386 // time spent in gc crosses a threshold, we will bail out.
387 loop_count++;
388 if ((result == nullptr) && (QueuedAllocationWarningCount > 0) &&
389 (loop_count % QueuedAllocationWarningCount == 0)) {
390 log_warning(gc)("ParallelScavengeHeap::mem_allocate retries %d times", loop_count);
391 log_warning(gc)("\tsize=" SIZE_FORMAT, size);
392 }
393 }
394
395 return result;
396 }
397
398 // A "death march" is a series of ultra-slow allocations in which a full gc is
399 // done before each allocation, and after the full gc the allocation still
400 // cannot be satisfied from the young gen. This routine detects that condition;
401 // it should be called after a full gc has been done and the allocation
402 // attempted from the young gen. The parameter 'addr' should be the result of
403 // that young gen allocation attempt.
404 void
405 ParallelScavengeHeap::death_march_check(HeapWord* const addr, size_t size) {
406 if (addr != nullptr) {
407 _death_march_count = 0; // death march has ended
408 } else if (_death_march_count == 0) {
409 if (should_alloc_in_eden(size)) {
410 _death_march_count = 1; // death march has started
411 }
412 }
413 }
414
415 HeapWord* ParallelScavengeHeap::allocate_old_gen_and_record(size_t size) {
416 assert_locked_or_safepoint(Heap_lock);
417 HeapWord* res = old_gen()->allocate(size);
418 if (res != nullptr) {
419 _size_policy->tenured_allocation(size * HeapWordSize);
420 }
421 return res;
422 }
423
424 HeapWord* ParallelScavengeHeap::mem_allocate_old_gen(size_t size) {
425 if (!should_alloc_in_eden(size) || GCLocker::is_active_and_needs_gc()) {
426 // Size is too big for eden, or gc is locked out.
427 return allocate_old_gen_and_record(size);
428 }
429
430 // If a "death march" is in progress, allocate from the old gen a limited
431 // number of times before doing a GC.
432 if (_death_march_count > 0) {
433 if (_death_march_count < 64) {
434 ++_death_march_count;
435 return allocate_old_gen_and_record(size);
436 } else {
437 _death_march_count = 0;
438 }
439 }
440 return nullptr;
441 }
442
443 void ParallelScavengeHeap::do_full_collection(bool clear_all_soft_refs) {
444 // The do_full_collection() parameter clear_all_soft_refs
445 // is interpreted here as maximum_compaction which will
446 // cause SoftRefs to be cleared.
447 bool maximum_compaction = clear_all_soft_refs;
448 PSParallelCompact::invoke(maximum_compaction);
449 }
450
451 // Failed allocation policy. Must be called from the VM thread, and
452 // only at a safepoint! Note that this method has policy for allocation
453 // flow, and NOT collection policy. So we do not check for gc collection
454 // time over limit here, that is the responsibility of the heap specific
455 // collection methods. This method decides where to attempt allocations,
456 // and when to attempt collections, but no collection specific policy.
457 HeapWord* ParallelScavengeHeap::failed_mem_allocate(size_t size) {
458 assert(SafepointSynchronize::is_at_safepoint(), "should be at safepoint");
459 assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread");
460 assert(!is_stw_gc_active(), "not reentrant");
461 assert(!Heap_lock->owned_by_self(), "this thread should not own the Heap_lock");
462
463 // We assume that allocation in eden will fail unless we collect.
464
465 // First level allocation failure, scavenge and allocate in young gen.
466 GCCauseSetter gccs(this, GCCause::_allocation_failure);
467 const bool invoked_full_gc = PSScavenge::invoke();
468 HeapWord* result = young_gen()->allocate(size);
469
470 // Second level allocation failure.
471 // Mark sweep and allocate in young generation.
472 if (result == nullptr && !invoked_full_gc) {
473 do_full_collection(false);
474 result = young_gen()->allocate(size);
475 }
476
477 death_march_check(result, size);
478
479 // Third level allocation failure.
480 // After mark sweep and young generation allocation failure,
481 // allocate in old generation.
482 if (result == nullptr) {
483 result = allocate_old_gen_and_record(size);
484 }
485
486 // Fourth level allocation failure. We're running out of memory.
487 // More complete mark sweep and allocate in young generation.
488 if (result == nullptr) {
489 do_full_collection(true);
490 result = young_gen()->allocate(size);
491 }
492
493 // Fifth level allocation failure.
494 // After more complete mark sweep, allocate in old generation.
495 if (result == nullptr) {
496 result = allocate_old_gen_and_record(size);
497 }
498
499 return result;
500 }
501
502 void ParallelScavengeHeap::ensure_parsability(bool retire_tlabs) {
503 CollectedHeap::ensure_parsability(retire_tlabs);
504 young_gen()->eden_space()->ensure_parsability();
505 }
506
507 size_t ParallelScavengeHeap::tlab_capacity(Thread* thr) const {
508 return young_gen()->eden_space()->tlab_capacity(thr);
509 }
510
511 size_t ParallelScavengeHeap::tlab_used(Thread* thr) const {
512 return young_gen()->eden_space()->tlab_used(thr);
513 }
514
515 size_t ParallelScavengeHeap::unsafe_max_tlab_alloc(Thread* thr) const {
516 return young_gen()->eden_space()->unsafe_max_tlab_alloc(thr);
517 }
518
519 HeapWord* ParallelScavengeHeap::allocate_new_tlab(size_t min_size, size_t requested_size, size_t* actual_size) {
520 HeapWord* result = young_gen()->allocate(requested_size);
521 if (result != nullptr) {
522 *actual_size = requested_size;
523 }
524
525 return result;
526 }
527
528 void ParallelScavengeHeap::resize_all_tlabs() {
529 CollectedHeap::resize_all_tlabs();
530 }
531
532 void ParallelScavengeHeap::prune_scavengable_nmethods() {
533 ScavengableNMethods::prune_nmethods_not_into_young();
534 }
535
536 void ParallelScavengeHeap::prune_unlinked_nmethods() {
537 ScavengableNMethods::prune_unlinked_nmethods();
538 }
539
540 // This method is used by System.gc() and JVMTI.
541 void ParallelScavengeHeap::collect(GCCause::Cause cause) {
542 assert(!Heap_lock->owned_by_self(),
543 "this thread should not own the Heap_lock");
544
545 uint gc_count = 0;
546 uint full_gc_count = 0;
547 {
548 MutexLocker ml(Heap_lock);
549 // This value is guarded by the Heap_lock
550 gc_count = total_collections();
551 full_gc_count = total_full_collections();
552 }
553
554 if (GCLocker::should_discard(cause, gc_count)) {
555 return;
556 }
557
558 while (true) {
559 VM_ParallelGCSystemGC op(gc_count, full_gc_count, cause);
560 VMThread::execute(&op);
561
562 if (!GCCause::is_explicit_full_gc(cause) || op.full_gc_succeeded()) {
563 return;
564 }
565
566 {
567 MutexLocker ml(Heap_lock);
568 if (full_gc_count != total_full_collections()) {
569 return;
570 }
571 }
572
573 if (GCLocker::is_active_and_needs_gc()) {
574 // If GCLocker is active, wait until clear before retrying.
575 GCLocker::stall_until_clear();
576 }
577 }
578 }
579
580 void ParallelScavengeHeap::object_iterate(ObjectClosure* cl) {
581 young_gen()->object_iterate(cl);
582 old_gen()->object_iterate(cl);
583 }
584
585 // The HeapBlockClaimer is used during parallel iteration over the heap,
586 // allowing workers to claim heap areas ("blocks"), gaining exclusive rights to these.
587 // The eden and survivor spaces are treated as single blocks as it is hard to divide
588 // these spaces.
589 // The old space is divided into fixed-size blocks.
590 class HeapBlockClaimer : public StackObj {
591 size_t _claimed_index;
592
593 public:
594 static const size_t InvalidIndex = SIZE_MAX;
595 static const size_t EdenIndex = 0;
596 static const size_t SurvivorIndex = 1;
597 static const size_t NumNonOldGenClaims = 2;
598
599 HeapBlockClaimer() : _claimed_index(EdenIndex) { }
600 // Claim the block and get the block index.
601 size_t claim_and_get_block() {
602 size_t block_index;
603 block_index = Atomic::fetch_then_add(&_claimed_index, 1u);
604
605 PSOldGen* old_gen = ParallelScavengeHeap::heap()->old_gen();
606 size_t num_claims = old_gen->num_iterable_blocks() + NumNonOldGenClaims;
607
608 return block_index < num_claims ? block_index : InvalidIndex;
609 }
610 };
611
612 void ParallelScavengeHeap::object_iterate_parallel(ObjectClosure* cl,
613 HeapBlockClaimer* claimer) {
614 size_t block_index = claimer->claim_and_get_block();
615 // Iterate until all blocks are claimed
616 if (block_index == HeapBlockClaimer::EdenIndex) {
617 young_gen()->eden_space()->object_iterate(cl);
618 block_index = claimer->claim_and_get_block();
619 }
620 if (block_index == HeapBlockClaimer::SurvivorIndex) {
621 young_gen()->from_space()->object_iterate(cl);
622 young_gen()->to_space()->object_iterate(cl);
623 block_index = claimer->claim_and_get_block();
624 }
625 while (block_index != HeapBlockClaimer::InvalidIndex) {
626 old_gen()->object_iterate_block(cl, block_index - HeapBlockClaimer::NumNonOldGenClaims);
627 block_index = claimer->claim_and_get_block();
628 }
629 }
630
631 class PSScavengeParallelObjectIterator : public ParallelObjectIteratorImpl {
632 private:
633 ParallelScavengeHeap* _heap;
634 HeapBlockClaimer _claimer;
635
636 public:
637 PSScavengeParallelObjectIterator() :
638 _heap(ParallelScavengeHeap::heap()),
639 _claimer() {}
640
641 virtual void object_iterate(ObjectClosure* cl, uint worker_id) {
642 _heap->object_iterate_parallel(cl, &_claimer);
643 }
644 };
645
646 ParallelObjectIteratorImpl* ParallelScavengeHeap::parallel_object_iterator(uint thread_num) {
647 return new PSScavengeParallelObjectIterator();
648 }
649
650 HeapWord* ParallelScavengeHeap::block_start(const void* addr) const {
651 if (young_gen()->is_in_reserved(addr)) {
652 assert(young_gen()->is_in(addr),
653 "addr should be in allocated part of young gen");
654 // called from os::print_location by find or VMError
655 if (DebuggingContext::is_enabled() || VMError::is_error_reported()) {
656 return nullptr;
657 }
658 Unimplemented();
659 } else if (old_gen()->is_in_reserved(addr)) {
660 assert(old_gen()->is_in(addr),
661 "addr should be in allocated part of old gen");
662 return old_gen()->start_array()->object_start((HeapWord*)addr);
663 }
664 return 0;
665 }
666
667 bool ParallelScavengeHeap::block_is_obj(const HeapWord* addr) const {
668 return block_start(addr) == addr;
669 }
670
671 void ParallelScavengeHeap::prepare_for_verify() {
672 ensure_parsability(false); // no need to retire TLABs for verification
673 }
674
675 PSHeapSummary ParallelScavengeHeap::create_ps_heap_summary() {
676 PSOldGen* old = old_gen();
677 HeapWord* old_committed_end = (HeapWord*)old->virtual_space()->committed_high_addr();
678 HeapWord* old_reserved_start = old->reserved().start();
679 HeapWord* old_reserved_end = old->reserved().end();
680 VirtualSpaceSummary old_summary(old_reserved_start, old_committed_end, old_reserved_end);
681 SpaceSummary old_space(old_reserved_start, old_committed_end, old->used_in_bytes());
682
683 PSYoungGen* young = young_gen();
684 VirtualSpaceSummary young_summary(young->reserved().start(),
685 (HeapWord*)young->virtual_space()->committed_high_addr(), young->reserved().end());
686
687 MutableSpace* eden = young_gen()->eden_space();
688 SpaceSummary eden_space(eden->bottom(), eden->end(), eden->used_in_bytes());
689
690 MutableSpace* from = young_gen()->from_space();
691 SpaceSummary from_space(from->bottom(), from->end(), from->used_in_bytes());
692
693 MutableSpace* to = young_gen()->to_space();
694 SpaceSummary to_space(to->bottom(), to->end(), to->used_in_bytes());
695
696 VirtualSpaceSummary heap_summary = create_heap_space_summary();
697 return PSHeapSummary(heap_summary, used(), old_summary, old_space, young_summary, eden_space, from_space, to_space);
698 }
699
700 bool ParallelScavengeHeap::print_location(outputStream* st, void* addr) const {
701 return BlockLocationPrinter<ParallelScavengeHeap>::print_location(st, addr);
702 }
703
704 void ParallelScavengeHeap::print_on(outputStream* st) const {
705 if (young_gen() != nullptr) {
706 young_gen()->print_on(st);
707 }
708 if (old_gen() != nullptr) {
709 old_gen()->print_on(st);
710 }
711 MetaspaceUtils::print_on(st);
712 }
713
714 void ParallelScavengeHeap::print_on_error(outputStream* st) const {
715 this->CollectedHeap::print_on_error(st);
716
717 st->cr();
718 PSParallelCompact::print_on_error(st);
719 }
720
721 void ParallelScavengeHeap::gc_threads_do(ThreadClosure* tc) const {
722 ParallelScavengeHeap::heap()->workers().threads_do(tc);
723 }
724
725 void ParallelScavengeHeap::print_tracing_info() const {
726 AdaptiveSizePolicyOutput::print();
727 log_debug(gc, heap, exit)("Accumulated young generation GC time %3.7f secs", PSScavenge::accumulated_time()->seconds());
728 log_debug(gc, heap, exit)("Accumulated old generation GC time %3.7f secs", PSParallelCompact::accumulated_time()->seconds());
729 }
730
731 PreGenGCValues ParallelScavengeHeap::get_pre_gc_values() const {
732 const PSYoungGen* const young = young_gen();
733 const MutableSpace* const eden = young->eden_space();
734 const MutableSpace* const from = young->from_space();
735 const PSOldGen* const old = old_gen();
736
737 return PreGenGCValues(young->used_in_bytes(),
738 young->capacity_in_bytes(),
739 eden->used_in_bytes(),
740 eden->capacity_in_bytes(),
741 from->used_in_bytes(),
742 from->capacity_in_bytes(),
743 old->used_in_bytes(),
744 old->capacity_in_bytes());
745 }
746
747 void ParallelScavengeHeap::print_heap_change(const PreGenGCValues& pre_gc_values) const {
748 const PSYoungGen* const young = young_gen();
749 const MutableSpace* const eden = young->eden_space();
750 const MutableSpace* const from = young->from_space();
751 const PSOldGen* const old = old_gen();
752
753 log_info(gc, heap)(HEAP_CHANGE_FORMAT" "
754 HEAP_CHANGE_FORMAT" "
755 HEAP_CHANGE_FORMAT,
756 HEAP_CHANGE_FORMAT_ARGS(young->name(),
757 pre_gc_values.young_gen_used(),
758 pre_gc_values.young_gen_capacity(),
759 young->used_in_bytes(),
760 young->capacity_in_bytes()),
761 HEAP_CHANGE_FORMAT_ARGS("Eden",
762 pre_gc_values.eden_used(),
763 pre_gc_values.eden_capacity(),
764 eden->used_in_bytes(),
765 eden->capacity_in_bytes()),
766 HEAP_CHANGE_FORMAT_ARGS("From",
767 pre_gc_values.from_used(),
768 pre_gc_values.from_capacity(),
769 from->used_in_bytes(),
770 from->capacity_in_bytes()));
771 log_info(gc, heap)(HEAP_CHANGE_FORMAT,
772 HEAP_CHANGE_FORMAT_ARGS(old->name(),
773 pre_gc_values.old_gen_used(),
774 pre_gc_values.old_gen_capacity(),
775 old->used_in_bytes(),
776 old->capacity_in_bytes()));
777 MetaspaceUtils::print_metaspace_change(pre_gc_values.metaspace_sizes());
778 }
779
780 void ParallelScavengeHeap::verify(VerifyOption option /* ignored */) {
781 // Why do we need the total_collections()-filter below?
782 if (total_collections() > 0) {
783 log_debug(gc, verify)("Tenured");
784 old_gen()->verify();
785
786 log_debug(gc, verify)("Eden");
787 young_gen()->verify();
788
789 log_debug(gc, verify)("CardTable");
790 card_table()->verify_all_young_refs_imprecise();
791 }
792 }
793
794 void ParallelScavengeHeap::trace_actual_reserved_page_size(const size_t reserved_heap_size, const ReservedSpace rs) {
795 // Check if Info level is enabled, since os::trace_page_sizes() logs on Info level.
796 if(log_is_enabled(Info, pagesize)) {
797 const size_t page_size = rs.page_size();
798 os::trace_page_sizes("Heap",
799 MinHeapSize,
800 reserved_heap_size,
801 rs.base(),
802 rs.size(),
803 page_size);
804 }
805 }
806
807 void ParallelScavengeHeap::trace_heap(GCWhen::Type when, const GCTracer* gc_tracer) {
808 const PSHeapSummary& heap_summary = create_ps_heap_summary();
809 gc_tracer->report_gc_heap_summary(when, heap_summary);
810
811 const MetaspaceSummary& metaspace_summary = create_metaspace_summary();
812 gc_tracer->report_metaspace_summary(when, metaspace_summary);
813 }
814
815 CardTableBarrierSet* ParallelScavengeHeap::barrier_set() {
816 return barrier_set_cast<CardTableBarrierSet>(BarrierSet::barrier_set());
817 }
818
819 PSCardTable* ParallelScavengeHeap::card_table() {
820 return static_cast<PSCardTable*>(barrier_set()->card_table());
821 }
822
823 void ParallelScavengeHeap::resize_young_gen(size_t eden_size,
824 size_t survivor_size) {
825 // Delegate the resize to the generation.
826 _young_gen->resize(eden_size, survivor_size);
827 }
828
829 void ParallelScavengeHeap::resize_old_gen(size_t desired_free_space) {
830 // Delegate the resize to the generation.
831 _old_gen->resize(desired_free_space);
832 }
833
834 HeapWord* ParallelScavengeHeap::allocate_loaded_archive_space(size_t size) {
835 return _old_gen->allocate(size);
836 }
837
838 void ParallelScavengeHeap::complete_loaded_archive_space(MemRegion archive_space) {
839 assert(_old_gen->object_space()->used_region().contains(archive_space),
840 "Archive space not contained in old gen");
841 _old_gen->complete_loaded_archive_space(archive_space);
842 }
843
844 void ParallelScavengeHeap::register_nmethod(nmethod* nm) {
845 ScavengableNMethods::register_nmethod(nm);
846 }
847
848 void ParallelScavengeHeap::unregister_nmethod(nmethod* nm) {
849 ScavengableNMethods::unregister_nmethod(nm);
850 }
851
852 void ParallelScavengeHeap::verify_nmethod(nmethod* nm) {
853 ScavengableNMethods::verify_nmethod(nm);
854 }
855
856 GrowableArray<GCMemoryManager*> ParallelScavengeHeap::memory_managers() {
857 GrowableArray<GCMemoryManager*> memory_managers(2);
858 memory_managers.append(_young_manager);
859 memory_managers.append(_old_manager);
860 return memory_managers;
861 }
862
863 GrowableArray<MemoryPool*> ParallelScavengeHeap::memory_pools() {
864 GrowableArray<MemoryPool*> memory_pools(3);
865 memory_pools.append(_eden_pool);
866 memory_pools.append(_survivor_pool);
867 memory_pools.append(_old_pool);
868 return memory_pools;
869 }
870
871 void ParallelScavengeHeap::pin_object(JavaThread* thread, oop obj) {
872 GCLocker::lock_critical(thread);
873 }
874
875 void ParallelScavengeHeap::unpin_object(JavaThread* thread, oop obj) {
876 GCLocker::unlock_critical(thread);
877 }
878
879 void ParallelScavengeHeap::update_parallel_worker_threads_cpu_time() {
880 assert(Thread::current()->is_VM_thread(),
881 "Must be called from VM thread to avoid races");
882 if (!UsePerfData || !os::is_thread_cpu_time_supported()) {
883 return;
884 }
885
886 // Ensure ThreadTotalCPUTimeClosure destructor is called before publishing gc
887 // time.
888 {
889 ThreadTotalCPUTimeClosure tttc(CPUTimeGroups::CPUTimeType::gc_parallel_workers);
890 // Currently parallel worker threads in GCTaskManager never terminate, so it
891 // is safe for VMThread to read their CPU times. If upstream changes this
892 // behavior, we should rethink if it is still safe.
893 gc_threads_do(&tttc);
894 }
895
896 CPUTimeCounters::publish_gc_total_cpu_time();
897 }