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/slidingForwarding.inline.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/universe.hpp"
49 #include "nmt/memTracker.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);
74 ReservedSpace young_rs = heap_rs.last_part(MaxOldSize);
75 assert(young_rs.size() == MaxNewSize, "Didn't reserve all of the heap");
76
77 PSCardTable* card_table = new PSCardTable(heap_rs.region());
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 (!PSParallelCompact::initialize_aux_data()) {
125 return JNI_ENOMEM;
126 }
127
128 // Create CPU time counter
129 CPUTimeCounters::create_counter(CPUTimeGroups::CPUTimeType::gc_parallel_workers);
130
131 ParallelInitLogger::print();
132
133 SlidingForwarding::initialize(heap_rs.region(), ParallelCompactData::RegionSize);
134
135 return JNI_OK;
136 }
137
138 void ParallelScavengeHeap::initialize_serviceability() {
139
140 _eden_pool = new EdenMutableSpacePool(_young_gen,
141 _young_gen->eden_space(),
142 "PS Eden Space",
143 false /* support_usage_threshold */);
144
145 _survivor_pool = new SurvivorMutableSpacePool(_young_gen,
146 "PS Survivor Space",
147 false /* support_usage_threshold */);
148
149 _old_pool = new PSGenerationPool(_old_gen,
150 "PS Old Gen",
151 true /* support_usage_threshold */);
152
153 _young_manager = new GCMemoryManager("PS Scavenge");
154 _old_manager = new GCMemoryManager("PS MarkSweep");
155
156 _old_manager->add_pool(_eden_pool);
157 _old_manager->add_pool(_survivor_pool);
158 _old_manager->add_pool(_old_pool);
159
160 _young_manager->add_pool(_eden_pool);
161 _young_manager->add_pool(_survivor_pool);
162
163 }
164
165 void ParallelScavengeHeap::safepoint_synchronize_begin() {
166 if (UseStringDeduplication) {
167 SuspendibleThreadSet::synchronize();
168 }
169 }
170
171 void ParallelScavengeHeap::safepoint_synchronize_end() {
172 if (UseStringDeduplication) {
173 SuspendibleThreadSet::desynchronize();
174 }
175 }
176 class PSIsScavengable : public BoolObjectClosure {
177 bool do_object_b(oop obj) {
178 return ParallelScavengeHeap::heap()->is_in_young(obj);
179 }
180 };
181
182 static PSIsScavengable _is_scavengable;
183
184 void ParallelScavengeHeap::post_initialize() {
185 CollectedHeap::post_initialize();
186 // Need to init the tenuring threshold
187 PSScavenge::initialize();
188 PSParallelCompact::post_initialize();
189 PSPromotionManager::initialize();
190
191 ScavengableNMethods::initialize(&_is_scavengable);
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(
270 size_t size,
271 bool* gc_overhead_limit_was_exceeded) {
272 assert(!SafepointSynchronize::is_at_safepoint(), "should not be at safepoint");
273 assert(Thread::current() != (Thread*)VMThread::vm_thread(), "should not be in vm thread");
274 assert(!Heap_lock->owned_by_self(), "this thread should not own the Heap_lock");
275
276 // In general gc_overhead_limit_was_exceeded should be false so
277 // set it so here and reset it to true only if the gc time
278 // limit is being exceeded as checked below.
279 *gc_overhead_limit_was_exceeded = false;
280
281 HeapWord* result = young_gen()->allocate(size);
282
283 uint loop_count = 0;
284 uint gc_count = 0;
285 uint gclocker_stalled_count = 0;
286
287 while (result == nullptr) {
288 // We don't want to have multiple collections for a single filled generation.
289 // To prevent this, each thread tracks the total_collections() value, and if
290 // the count has changed, does not do a new collection.
291 //
292 // The collection count must be read only while holding the heap lock. VM
293 // operations also hold the heap lock during collections. There is a lock
294 // contention case where thread A blocks waiting on the Heap_lock, while
295 // thread B is holding it doing a collection. When thread A gets the lock,
296 // the collection count has already changed. To prevent duplicate collections,
297 // The policy MUST attempt allocations during the same period it reads the
298 // total_collections() value!
299 {
300 MutexLocker ml(Heap_lock);
301 gc_count = total_collections();
302
303 result = young_gen()->allocate(size);
304 if (result != nullptr) {
305 return result;
306 }
307
308 // If certain conditions hold, try allocating from the old gen.
309 result = mem_allocate_old_gen(size);
310 if (result != nullptr) {
311 return result;
312 }
313
314 if (gclocker_stalled_count > GCLockerRetryAllocationCount) {
315 return nullptr;
316 }
317
318 // Failed to allocate without a gc.
319 if (GCLocker::is_active_and_needs_gc()) {
320 // If this thread is not in a jni critical section, we stall
321 // the requestor until the critical section has cleared and
322 // GC allowed. When the critical section clears, a GC is
323 // initiated by the last thread exiting the critical section; so
324 // we retry the allocation sequence from the beginning of the loop,
325 // rather than causing more, now probably unnecessary, GC attempts.
326 JavaThread* jthr = JavaThread::current();
327 if (!jthr->in_critical()) {
328 MutexUnlocker mul(Heap_lock);
329 GCLocker::stall_until_clear();
330 gclocker_stalled_count += 1;
331 continue;
332 } else {
333 if (CheckJNICalls) {
334 fatal("Possible deadlock due to allocating while"
335 " in jni critical section");
336 }
337 return nullptr;
338 }
339 }
340 }
341
342 if (result == nullptr) {
343 // Generate a VM operation
344 VM_ParallelGCFailedAllocation op(size, gc_count);
345 VMThread::execute(&op);
346
347 // Did the VM operation execute? If so, return the result directly.
348 // This prevents us from looping until time out on requests that can
349 // not be satisfied.
350 if (op.prologue_succeeded()) {
351 assert(is_in_or_null(op.result()), "result not in heap");
352
353 // If GC was locked out during VM operation then retry allocation
354 // and/or stall as necessary.
355 if (op.gc_locked()) {
356 assert(op.result() == nullptr, "must be null if gc_locked() is true");
357 continue; // retry and/or stall as necessary
358 }
359
360 // Exit the loop if the gc time limit has been exceeded.
361 // The allocation must have failed above ("result" guarding
362 // this path is null) and the most recent collection has exceeded the
363 // gc overhead limit (although enough may have been collected to
364 // satisfy the allocation). Exit the loop so that an out-of-memory
365 // will be thrown (return a null ignoring the contents of
366 // op.result()),
367 // but clear gc_overhead_limit_exceeded so that the next collection
368 // starts with a clean slate (i.e., forgets about previous overhead
369 // excesses). Fill op.result() with a filler object so that the
370 // heap remains parsable.
371 const bool limit_exceeded = size_policy()->gc_overhead_limit_exceeded();
372 const bool softrefs_clear = soft_ref_policy()->all_soft_refs_clear();
373
374 if (limit_exceeded && softrefs_clear) {
375 *gc_overhead_limit_was_exceeded = true;
376 size_policy()->set_gc_overhead_limit_exceeded(false);
377 log_trace(gc)("ParallelScavengeHeap::mem_allocate: return null because gc_overhead_limit_exceeded is set");
378 if (op.result() != nullptr) {
379 CollectedHeap::fill_with_object(op.result(), size);
380 }
381 return nullptr;
382 }
383
384 return op.result();
385 }
386 }
387
388 // The policy object will prevent us from looping forever. If the
389 // time spent in gc crosses a threshold, we will bail out.
390 loop_count++;
391 if ((result == nullptr) && (QueuedAllocationWarningCount > 0) &&
392 (loop_count % QueuedAllocationWarningCount == 0)) {
393 log_warning(gc)("ParallelScavengeHeap::mem_allocate retries %d times", loop_count);
394 log_warning(gc)("\tsize=" SIZE_FORMAT, size);
395 }
396 }
397
398 return result;
399 }
400
401 // A "death march" is a series of ultra-slow allocations in which a full gc is
402 // done before each allocation, and after the full gc the allocation still
403 // cannot be satisfied from the young gen. This routine detects that condition;
404 // it should be called after a full gc has been done and the allocation
405 // attempted from the young gen. The parameter 'addr' should be the result of
406 // that young gen allocation attempt.
407 void
408 ParallelScavengeHeap::death_march_check(HeapWord* const addr, size_t size) {
409 if (addr != nullptr) {
410 _death_march_count = 0; // death march has ended
411 } else if (_death_march_count == 0) {
412 if (should_alloc_in_eden(size)) {
413 _death_march_count = 1; // death march has started
414 }
415 }
416 }
417
418 HeapWord* ParallelScavengeHeap::allocate_old_gen_and_record(size_t size) {
419 assert_locked_or_safepoint(Heap_lock);
420 HeapWord* res = old_gen()->allocate(size);
421 if (res != nullptr) {
422 _size_policy->tenured_allocation(size * HeapWordSize);
423 }
424 return res;
425 }
426
427 HeapWord* ParallelScavengeHeap::mem_allocate_old_gen(size_t size) {
428 if (!should_alloc_in_eden(size) || GCLocker::is_active_and_needs_gc()) {
429 // Size is too big for eden, or gc is locked out.
430 return allocate_old_gen_and_record(size);
431 }
432
433 // If a "death march" is in progress, allocate from the old gen a limited
434 // number of times before doing a GC.
435 if (_death_march_count > 0) {
436 if (_death_march_count < 64) {
437 ++_death_march_count;
438 return allocate_old_gen_and_record(size);
439 } else {
440 _death_march_count = 0;
441 }
442 }
443 return nullptr;
444 }
445
446 void ParallelScavengeHeap::do_full_collection(bool clear_all_soft_refs) {
447 // The do_full_collection() parameter clear_all_soft_refs
448 // is interpreted here as maximum_compaction which will
449 // cause SoftRefs to be cleared.
450 bool maximum_compaction = clear_all_soft_refs;
451 PSParallelCompact::invoke(maximum_compaction);
452 }
453
454 // Failed allocation policy. Must be called from the VM thread, and
455 // only at a safepoint! Note that this method has policy for allocation
456 // flow, and NOT collection policy. So we do not check for gc collection
457 // time over limit here, that is the responsibility of the heap specific
458 // collection methods. This method decides where to attempt allocations,
459 // and when to attempt collections, but no collection specific policy.
460 HeapWord* ParallelScavengeHeap::failed_mem_allocate(size_t size) {
461 assert(SafepointSynchronize::is_at_safepoint(), "should be at safepoint");
462 assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread");
463 assert(!is_stw_gc_active(), "not reentrant");
464 assert(!Heap_lock->owned_by_self(), "this thread should not own the Heap_lock");
465
466 // We assume that allocation in eden will fail unless we collect.
467
468 // First level allocation failure, scavenge and allocate in young gen.
469 GCCauseSetter gccs(this, GCCause::_allocation_failure);
470 const bool invoked_full_gc = PSScavenge::invoke();
471 HeapWord* result = young_gen()->allocate(size);
472
473 // Second level allocation failure.
474 // Mark sweep and allocate in young generation.
475 if (result == nullptr && !invoked_full_gc) {
476 do_full_collection(false);
477 result = young_gen()->allocate(size);
478 }
479
480 death_march_check(result, size);
481
482 // Third level allocation failure.
483 // After mark sweep and young generation allocation failure,
484 // allocate in old generation.
485 if (result == nullptr) {
486 result = allocate_old_gen_and_record(size);
487 }
488
489 // Fourth level allocation failure. We're running out of memory.
490 // More complete mark sweep and allocate in young generation.
491 if (result == nullptr) {
492 do_full_collection(true);
493 result = young_gen()->allocate(size);
494 }
495
496 // Fifth level allocation failure.
497 // After more complete mark sweep, allocate in old generation.
498 if (result == nullptr) {
499 result = allocate_old_gen_and_record(size);
500 }
501
502 return result;
503 }
504
505 void ParallelScavengeHeap::ensure_parsability(bool retire_tlabs) {
506 CollectedHeap::ensure_parsability(retire_tlabs);
507 young_gen()->eden_space()->ensure_parsability();
508 }
509
510 size_t ParallelScavengeHeap::tlab_capacity(Thread* thr) const {
511 return young_gen()->eden_space()->tlab_capacity(thr);
512 }
513
514 size_t ParallelScavengeHeap::tlab_used(Thread* thr) const {
515 return young_gen()->eden_space()->tlab_used(thr);
516 }
517
518 size_t ParallelScavengeHeap::unsafe_max_tlab_alloc(Thread* thr) const {
519 return young_gen()->eden_space()->unsafe_max_tlab_alloc(thr);
520 }
521
522 HeapWord* ParallelScavengeHeap::allocate_new_tlab(size_t min_size, size_t requested_size, size_t* actual_size) {
523 HeapWord* result = young_gen()->allocate(requested_size);
524 if (result != nullptr) {
525 *actual_size = requested_size;
526 }
527
528 return result;
529 }
530
531 void ParallelScavengeHeap::resize_all_tlabs() {
532 CollectedHeap::resize_all_tlabs();
533 }
534
535 void ParallelScavengeHeap::prune_scavengable_nmethods() {
536 ScavengableNMethods::prune_nmethods_not_into_young();
537 }
538
539 void ParallelScavengeHeap::prune_unlinked_nmethods() {
540 ScavengableNMethods::prune_unlinked_nmethods();
541 }
542
543 // This method is used by System.gc() and JVMTI.
544 void ParallelScavengeHeap::collect(GCCause::Cause cause) {
545 assert(!Heap_lock->owned_by_self(),
546 "this thread should not own the Heap_lock");
547
548 uint gc_count = 0;
549 uint full_gc_count = 0;
550 {
551 MutexLocker ml(Heap_lock);
552 // This value is guarded by the Heap_lock
553 gc_count = total_collections();
554 full_gc_count = total_full_collections();
555 }
556
557 if (GCLocker::should_discard(cause, gc_count)) {
558 return;
559 }
560
561 while (true) {
562 VM_ParallelGCSystemGC op(gc_count, full_gc_count, cause);
563 VMThread::execute(&op);
564
565 if (!GCCause::is_explicit_full_gc(cause) || op.full_gc_succeeded()) {
566 return;
567 }
568
569 {
570 MutexLocker ml(Heap_lock);
571 if (full_gc_count != total_full_collections()) {
572 return;
573 }
574 }
575
576 if (GCLocker::is_active_and_needs_gc()) {
577 // If GCLocker is active, wait until clear before retrying.
578 GCLocker::stall_until_clear();
579 }
580 }
581 }
582
583 void ParallelScavengeHeap::object_iterate(ObjectClosure* cl) {
584 young_gen()->object_iterate(cl);
585 old_gen()->object_iterate(cl);
586 }
587
588 // The HeapBlockClaimer is used during parallel iteration over the heap,
589 // allowing workers to claim heap areas ("blocks"), gaining exclusive rights to these.
590 // The eden and survivor spaces are treated as single blocks as it is hard to divide
591 // these spaces.
592 // The old space is divided into fixed-size blocks.
593 class HeapBlockClaimer : public StackObj {
594 size_t _claimed_index;
595
596 public:
597 static const size_t InvalidIndex = SIZE_MAX;
598 static const size_t EdenIndex = 0;
599 static const size_t SurvivorIndex = 1;
600 static const size_t NumNonOldGenClaims = 2;
601
602 HeapBlockClaimer() : _claimed_index(EdenIndex) { }
603 // Claim the block and get the block index.
604 size_t claim_and_get_block() {
605 size_t block_index;
606 block_index = Atomic::fetch_then_add(&_claimed_index, 1u);
607
608 PSOldGen* old_gen = ParallelScavengeHeap::heap()->old_gen();
609 size_t num_claims = old_gen->num_iterable_blocks() + NumNonOldGenClaims;
610
611 return block_index < num_claims ? block_index : InvalidIndex;
612 }
613 };
614
615 void ParallelScavengeHeap::object_iterate_parallel(ObjectClosure* cl,
616 HeapBlockClaimer* claimer) {
617 size_t block_index = claimer->claim_and_get_block();
618 // Iterate until all blocks are claimed
619 if (block_index == HeapBlockClaimer::EdenIndex) {
620 young_gen()->eden_space()->object_iterate(cl);
621 block_index = claimer->claim_and_get_block();
622 }
623 if (block_index == HeapBlockClaimer::SurvivorIndex) {
624 young_gen()->from_space()->object_iterate(cl);
625 young_gen()->to_space()->object_iterate(cl);
626 block_index = claimer->claim_and_get_block();
627 }
628 while (block_index != HeapBlockClaimer::InvalidIndex) {
629 old_gen()->object_iterate_block(cl, block_index - HeapBlockClaimer::NumNonOldGenClaims);
630 block_index = claimer->claim_and_get_block();
631 }
632 }
633
634 class PSScavengeParallelObjectIterator : public ParallelObjectIteratorImpl {
635 private:
636 ParallelScavengeHeap* _heap;
637 HeapBlockClaimer _claimer;
638
639 public:
640 PSScavengeParallelObjectIterator() :
641 _heap(ParallelScavengeHeap::heap()),
642 _claimer() {}
643
644 virtual void object_iterate(ObjectClosure* cl, uint worker_id) {
645 _heap->object_iterate_parallel(cl, &_claimer);
646 }
647 };
648
649 ParallelObjectIteratorImpl* ParallelScavengeHeap::parallel_object_iterator(uint thread_num) {
650 return new PSScavengeParallelObjectIterator();
651 }
652
653 HeapWord* ParallelScavengeHeap::block_start(const void* addr) const {
654 if (young_gen()->is_in_reserved(addr)) {
655 assert(young_gen()->is_in(addr),
656 "addr should be in allocated part of young gen");
657 // called from os::print_location by find or VMError
658 if (DebuggingContext::is_enabled() || VMError::is_error_reported()) {
659 return nullptr;
660 }
661 Unimplemented();
662 } else if (old_gen()->is_in_reserved(addr)) {
663 assert(old_gen()->is_in(addr),
664 "addr should be in allocated part of old gen");
665 return old_gen()->start_array()->object_start((HeapWord*)addr);
666 }
667 return 0;
668 }
669
670 bool ParallelScavengeHeap::block_is_obj(const HeapWord* addr) const {
671 return block_start(addr) == addr;
672 }
673
674 void ParallelScavengeHeap::prepare_for_verify() {
675 ensure_parsability(false); // no need to retire TLABs for verification
676 }
677
678 PSHeapSummary ParallelScavengeHeap::create_ps_heap_summary() {
679 PSOldGen* old = old_gen();
680 HeapWord* old_committed_end = (HeapWord*)old->virtual_space()->committed_high_addr();
681 HeapWord* old_reserved_start = old->reserved().start();
682 HeapWord* old_reserved_end = old->reserved().end();
683 VirtualSpaceSummary old_summary(old_reserved_start, old_committed_end, old_reserved_end);
684 SpaceSummary old_space(old_reserved_start, old_committed_end, old->used_in_bytes());
685
686 PSYoungGen* young = young_gen();
687 VirtualSpaceSummary young_summary(young->reserved().start(),
688 (HeapWord*)young->virtual_space()->committed_high_addr(), young->reserved().end());
689
690 MutableSpace* eden = young_gen()->eden_space();
691 SpaceSummary eden_space(eden->bottom(), eden->end(), eden->used_in_bytes());
692
693 MutableSpace* from = young_gen()->from_space();
694 SpaceSummary from_space(from->bottom(), from->end(), from->used_in_bytes());
695
696 MutableSpace* to = young_gen()->to_space();
697 SpaceSummary to_space(to->bottom(), to->end(), to->used_in_bytes());
698
699 VirtualSpaceSummary heap_summary = create_heap_space_summary();
700 return PSHeapSummary(heap_summary, used(), old_summary, old_space, young_summary, eden_space, from_space, to_space);
701 }
702
703 bool ParallelScavengeHeap::print_location(outputStream* st, void* addr) const {
704 return BlockLocationPrinter<ParallelScavengeHeap>::print_location(st, addr);
705 }
706
707 void ParallelScavengeHeap::print_on(outputStream* st) const {
708 if (young_gen() != nullptr) {
709 young_gen()->print_on(st);
710 }
711 if (old_gen() != nullptr) {
712 old_gen()->print_on(st);
713 }
714 MetaspaceUtils::print_on(st);
715 }
716
717 void ParallelScavengeHeap::print_on_error(outputStream* st) const {
718 this->CollectedHeap::print_on_error(st);
719
720 st->cr();
721 PSParallelCompact::print_on_error(st);
722 }
723
724 void ParallelScavengeHeap::gc_threads_do(ThreadClosure* tc) const {
725 ParallelScavengeHeap::heap()->workers().threads_do(tc);
726 }
727
728 void ParallelScavengeHeap::print_tracing_info() const {
729 AdaptiveSizePolicyOutput::print();
730 log_debug(gc, heap, exit)("Accumulated young generation GC time %3.7f secs", PSScavenge::accumulated_time()->seconds());
731 log_debug(gc, heap, exit)("Accumulated old generation GC time %3.7f secs", PSParallelCompact::accumulated_time()->seconds());
732 }
733
734 PreGenGCValues ParallelScavengeHeap::get_pre_gc_values() const {
735 const PSYoungGen* const young = young_gen();
736 const MutableSpace* const eden = young->eden_space();
737 const MutableSpace* const from = young->from_space();
738 const PSOldGen* const old = old_gen();
739
740 return PreGenGCValues(young->used_in_bytes(),
741 young->capacity_in_bytes(),
742 eden->used_in_bytes(),
743 eden->capacity_in_bytes(),
744 from->used_in_bytes(),
745 from->capacity_in_bytes(),
746 old->used_in_bytes(),
747 old->capacity_in_bytes());
748 }
749
750 void ParallelScavengeHeap::print_heap_change(const PreGenGCValues& pre_gc_values) const {
751 const PSYoungGen* const young = young_gen();
752 const MutableSpace* const eden = young->eden_space();
753 const MutableSpace* const from = young->from_space();
754 const PSOldGen* const old = old_gen();
755
756 log_info(gc, heap)(HEAP_CHANGE_FORMAT" "
757 HEAP_CHANGE_FORMAT" "
758 HEAP_CHANGE_FORMAT,
759 HEAP_CHANGE_FORMAT_ARGS(young->name(),
760 pre_gc_values.young_gen_used(),
761 pre_gc_values.young_gen_capacity(),
762 young->used_in_bytes(),
763 young->capacity_in_bytes()),
764 HEAP_CHANGE_FORMAT_ARGS("Eden",
765 pre_gc_values.eden_used(),
766 pre_gc_values.eden_capacity(),
767 eden->used_in_bytes(),
768 eden->capacity_in_bytes()),
769 HEAP_CHANGE_FORMAT_ARGS("From",
770 pre_gc_values.from_used(),
771 pre_gc_values.from_capacity(),
772 from->used_in_bytes(),
773 from->capacity_in_bytes()));
774 log_info(gc, heap)(HEAP_CHANGE_FORMAT,
775 HEAP_CHANGE_FORMAT_ARGS(old->name(),
776 pre_gc_values.old_gen_used(),
777 pre_gc_values.old_gen_capacity(),
778 old->used_in_bytes(),
779 old->capacity_in_bytes()));
780 MetaspaceUtils::print_metaspace_change(pre_gc_values.metaspace_sizes());
781 }
782
783 void ParallelScavengeHeap::verify(VerifyOption option /* ignored */) {
784 // Why do we need the total_collections()-filter below?
785 if (total_collections() > 0) {
786 log_debug(gc, verify)("Tenured");
787 old_gen()->verify();
788
789 log_debug(gc, verify)("Eden");
790 young_gen()->verify();
791
792 log_debug(gc, verify)("CardTable");
793 card_table()->verify_all_young_refs_imprecise();
794 }
795 }
796
797 void ParallelScavengeHeap::trace_actual_reserved_page_size(const size_t reserved_heap_size, const ReservedSpace rs) {
798 // Check if Info level is enabled, since os::trace_page_sizes() logs on Info level.
799 if(log_is_enabled(Info, pagesize)) {
800 const size_t page_size = rs.page_size();
801 os::trace_page_sizes("Heap",
802 MinHeapSize,
803 reserved_heap_size,
804 rs.base(),
805 rs.size(),
806 page_size);
807 }
808 }
809
810 void ParallelScavengeHeap::trace_heap(GCWhen::Type when, const GCTracer* gc_tracer) {
811 const PSHeapSummary& heap_summary = create_ps_heap_summary();
812 gc_tracer->report_gc_heap_summary(when, heap_summary);
813
814 const MetaspaceSummary& metaspace_summary = create_metaspace_summary();
815 gc_tracer->report_metaspace_summary(when, metaspace_summary);
816 }
817
818 CardTableBarrierSet* ParallelScavengeHeap::barrier_set() {
819 return barrier_set_cast<CardTableBarrierSet>(BarrierSet::barrier_set());
820 }
821
822 PSCardTable* ParallelScavengeHeap::card_table() {
823 return static_cast<PSCardTable*>(barrier_set()->card_table());
824 }
825
826 void ParallelScavengeHeap::resize_young_gen(size_t eden_size,
827 size_t survivor_size) {
828 // Delegate the resize to the generation.
829 _young_gen->resize(eden_size, survivor_size);
830 }
831
832 void ParallelScavengeHeap::resize_old_gen(size_t desired_free_space) {
833 // Delegate the resize to the generation.
834 _old_gen->resize(desired_free_space);
835 }
836
837 HeapWord* ParallelScavengeHeap::allocate_loaded_archive_space(size_t size) {
838 return _old_gen->allocate(size);
839 }
840
841 void ParallelScavengeHeap::complete_loaded_archive_space(MemRegion archive_space) {
842 assert(_old_gen->object_space()->used_region().contains(archive_space),
843 "Archive space not contained in old gen");
844 _old_gen->complete_loaded_archive_space(archive_space);
845 }
846
847 void ParallelScavengeHeap::register_nmethod(nmethod* nm) {
848 ScavengableNMethods::register_nmethod(nm);
849 }
850
851 void ParallelScavengeHeap::unregister_nmethod(nmethod* nm) {
852 ScavengableNMethods::unregister_nmethod(nm);
853 }
854
855 void ParallelScavengeHeap::verify_nmethod(nmethod* nm) {
856 ScavengableNMethods::verify_nmethod(nm);
857 }
858
859 GrowableArray<GCMemoryManager*> ParallelScavengeHeap::memory_managers() {
860 GrowableArray<GCMemoryManager*> memory_managers(2);
861 memory_managers.append(_young_manager);
862 memory_managers.append(_old_manager);
863 return memory_managers;
864 }
865
866 GrowableArray<MemoryPool*> ParallelScavengeHeap::memory_pools() {
867 GrowableArray<MemoryPool*> memory_pools(3);
868 memory_pools.append(_eden_pool);
869 memory_pools.append(_survivor_pool);
870 memory_pools.append(_old_pool);
871 return memory_pools;
872 }
873
874 void ParallelScavengeHeap::pin_object(JavaThread* thread, oop obj) {
875 GCLocker::lock_critical(thread);
876 }
877
878 void ParallelScavengeHeap::unpin_object(JavaThread* thread, oop obj) {
879 GCLocker::unlock_critical(thread);
880 }
881
882 void ParallelScavengeHeap::update_parallel_worker_threads_cpu_time() {
883 assert(Thread::current()->is_VM_thread(),
884 "Must be called from VM thread to avoid races");
885 if (!UsePerfData || !os::is_thread_cpu_time_supported()) {
886 return;
887 }
888
889 // Ensure ThreadTotalCPUTimeClosure destructor is called before publishing gc
890 // time.
891 {
892 ThreadTotalCPUTimeClosure tttc(CPUTimeGroups::CPUTimeType::gc_parallel_workers);
893 // Currently parallel worker threads in GCTaskManager never terminate, so it
894 // is safe for VMThread to read their CPU times. If upstream changes this
895 // behavior, we should rethink if it is still safe.
896 gc_threads_do(&tttc);
897 }
898
899 CPUTimeCounters::publish_gc_total_cpu_time();
900 }