1 /*
2 * Copyright (c) 2001, 2018, 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 "code/codeCache.hpp"
27 #include "gc/parallel/adjoiningGenerations.hpp"
28 #include "gc/parallel/adjoiningGenerationsForHeteroHeap.hpp"
29 #include "gc/parallel/adjoiningVirtualSpaces.hpp"
30 #include "gc/parallel/gcTaskManager.hpp"
31 #include "gc/parallel/generationSizer.hpp"
32 #include "gc/parallel/objectStartArray.inline.hpp"
33 #include "gc/parallel/parallelScavengeHeap.inline.hpp"
34 #include "gc/parallel/psAdaptiveSizePolicy.hpp"
35 #include "gc/parallel/psMarkSweepProxy.hpp"
36 #include "gc/parallel/psMemoryPool.hpp"
37 #include "gc/parallel/psParallelCompact.inline.hpp"
38 #include "gc/parallel/psPromotionManager.hpp"
39 #include "gc/parallel/psScavenge.hpp"
40 #include "gc/parallel/psVMOperations.hpp"
41 #include "gc/shared/gcHeapSummary.hpp"
42 #include "gc/shared/gcLocker.hpp"
43 #include "gc/shared/gcWhen.hpp"
44 #include "gc/shared/scavengableNMethods.hpp"
45 #include "logging/log.hpp"
46 #include "memory/metaspaceCounters.hpp"
47 #include "oops/oop.inline.hpp"
48 #include "runtime/handles.inline.hpp"
49 #include "runtime/java.hpp"
50 #include "runtime/vmThread.hpp"
51 #include "services/memoryManager.hpp"
52 #include "services/memTracker.hpp"
53 #include "utilities/macros.hpp"
54 #include "utilities/vmError.hpp"
55
56 PSYoungGen* ParallelScavengeHeap::_young_gen = NULL;
57 PSOldGen* ParallelScavengeHeap::_old_gen = NULL;
58 PSAdaptiveSizePolicy* ParallelScavengeHeap::_size_policy = NULL;
59 PSGCAdaptivePolicyCounters* ParallelScavengeHeap::_gc_policy_counters = NULL;
60 GCTaskManager* ParallelScavengeHeap::_gc_task_manager = NULL;
61
62 jint ParallelScavengeHeap::initialize() {
63 size_t heap_size = _collector_policy->heap_reserved_size_bytes();
64
65 ReservedSpace heap_rs = Universe::reserve_heap(heap_size, _collector_policy->heap_alignment());
66
67 os::trace_page_sizes("Heap",
68 _collector_policy->min_heap_byte_size(),
69 heap_size,
70 generation_alignment(),
71 heap_rs.base(),
72 heap_rs.size());
73
74 initialize_reserved_region((HeapWord*)heap_rs.base(), (HeapWord*)(heap_rs.base() + heap_rs.size()));
75
76 PSCardTable* card_table = new PSCardTable(reserved_region());
77 card_table->initialize();
78 CardTableBarrierSet* const barrier_set = new CardTableBarrierSet(card_table);
79 barrier_set->initialize();
80 BarrierSet::set_barrier_set(barrier_set);
81
82 // Make up the generations
83 // Calculate the maximum size that a generation can grow. This
84 // includes growth into the other generation. Note that the
85 // parameter _max_gen_size is kept as the maximum
86 // size of the generation as the boundaries currently stand.
87 // _max_gen_size is still used as that value.
88 double max_gc_pause_sec = ((double) MaxGCPauseMillis)/1000.0;
89 double max_gc_minor_pause_sec = ((double) MaxGCMinorPauseMillis)/1000.0;
90
91 _gens = AdjoiningGenerations::create_adjoining_generations(heap_rs, _collector_policy, generation_alignment());
92
93 _old_gen = _gens->old_gen();
94 _young_gen = _gens->young_gen();
95
96 const size_t eden_capacity = _young_gen->eden_space()->capacity_in_bytes();
97 const size_t old_capacity = _old_gen->capacity_in_bytes();
98 const size_t initial_promo_size = MIN2(eden_capacity, old_capacity);
99 _size_policy =
100 new PSAdaptiveSizePolicy(eden_capacity,
101 initial_promo_size,
102 young_gen()->to_space()->capacity_in_bytes(),
103 _collector_policy->gen_alignment(),
104 max_gc_pause_sec,
105 max_gc_minor_pause_sec,
106 GCTimeRatio
107 );
108
109 assert(_collector_policy->is_hetero_heap() || !UseAdaptiveGCBoundary ||
110 (old_gen()->virtual_space()->high_boundary() ==
111 young_gen()->virtual_space()->low_boundary()),
112 "Boundaries must meet");
113 // initialize the policy counters - 2 collectors, 2 generations
114 _gc_policy_counters =
115 new PSGCAdaptivePolicyCounters("ParScav:MSC", 2, 2, _size_policy);
116
117 // Set up the GCTaskManager
118 _gc_task_manager = GCTaskManager::create(ParallelGCThreads);
119
120 if (UseParallelOldGC && !PSParallelCompact::initialize()) {
121 return JNI_ENOMEM;
122 }
123
124 return JNI_OK;
125 }
126
127 void ParallelScavengeHeap::initialize_serviceability() {
128
129 _eden_pool = new EdenMutableSpacePool(_young_gen,
130 _young_gen->eden_space(),
131 "PS Eden Space",
132 false /* support_usage_threshold */);
133
134 _survivor_pool = new SurvivorMutableSpacePool(_young_gen,
135 "PS Survivor Space",
136 false /* support_usage_threshold */);
137
138 _old_pool = new PSGenerationPool(_old_gen,
139 "PS Old Gen",
140 true /* support_usage_threshold */);
141
142 _young_manager = new GCMemoryManager("PS Scavenge", "end of minor GC");
143 _old_manager = new GCMemoryManager("PS MarkSweep", "end of major GC");
144
145 _old_manager->add_pool(_eden_pool);
146 _old_manager->add_pool(_survivor_pool);
147 _old_manager->add_pool(_old_pool);
148
149 _young_manager->add_pool(_eden_pool);
150 _young_manager->add_pool(_survivor_pool);
151
152 }
153
154 class PSIsScavengable : public BoolObjectClosure {
155 bool do_object_b(oop obj) {
156 return ParallelScavengeHeap::heap()->is_in_young(obj);
157 }
158 };
159
160 static PSIsScavengable _is_scavengable;
161
162 void ParallelScavengeHeap::post_initialize() {
163 CollectedHeap::post_initialize();
164 // Need to init the tenuring threshold
165 PSScavenge::initialize();
166 if (UseParallelOldGC) {
167 PSParallelCompact::post_initialize();
168 } else {
169 PSMarkSweepProxy::initialize();
170 }
171 PSPromotionManager::initialize();
172
173 ScavengableNMethods::initialize(&_is_scavengable);
174 }
175
176 void ParallelScavengeHeap::update_counters() {
177 young_gen()->update_counters();
178 old_gen()->update_counters();
179 MetaspaceCounters::update_performance_counters();
180 CompressedClassSpaceCounters::update_performance_counters();
181 }
182
183 size_t ParallelScavengeHeap::capacity() const {
184 size_t value = young_gen()->capacity_in_bytes() + old_gen()->capacity_in_bytes();
185 return value;
186 }
187
188 size_t ParallelScavengeHeap::used() const {
189 size_t value = young_gen()->used_in_bytes() + old_gen()->used_in_bytes();
190 return value;
191 }
192
193 bool ParallelScavengeHeap::is_maximal_no_gc() const {
194 return old_gen()->is_maximal_no_gc() && young_gen()->is_maximal_no_gc();
195 }
196
197
198 size_t ParallelScavengeHeap::max_capacity() const {
199 size_t estimated = reserved_region().byte_size();
200 if (UseAdaptiveSizePolicy) {
201 estimated -= _size_policy->max_survivor_size(young_gen()->max_size());
202 } else {
203 estimated -= young_gen()->to_space()->capacity_in_bytes();
204 }
205 return MAX2(estimated, capacity());
206 }
207
208 bool ParallelScavengeHeap::is_in(const void* p) const {
209 return young_gen()->is_in(p) || old_gen()->is_in(p);
210 }
211
212 bool ParallelScavengeHeap::is_in_reserved(const void* p) const {
213 return young_gen()->is_in_reserved(p) || old_gen()->is_in_reserved(p);
214 }
215
216 // There are two levels of allocation policy here.
217 //
218 // When an allocation request fails, the requesting thread must invoke a VM
219 // operation, transfer control to the VM thread, and await the results of a
220 // garbage collection. That is quite expensive, and we should avoid doing it
221 // multiple times if possible.
222 //
223 // To accomplish this, we have a basic allocation policy, and also a
224 // failed allocation policy.
225 //
226 // The basic allocation policy controls how you allocate memory without
227 // attempting garbage collection. It is okay to grab locks and
228 // expand the heap, if that can be done without coming to a safepoint.
229 // It is likely that the basic allocation policy will not be very
230 // aggressive.
231 //
232 // The failed allocation policy is invoked from the VM thread after
233 // the basic allocation policy is unable to satisfy a mem_allocate
234 // request. This policy needs to cover the entire range of collection,
235 // heap expansion, and out-of-memory conditions. It should make every
236 // attempt to allocate the requested memory.
237
238 // Basic allocation policy. Should never be called at a safepoint, or
239 // from the VM thread.
240 //
241 // This method must handle cases where many mem_allocate requests fail
242 // simultaneously. When that happens, only one VM operation will succeed,
243 // and the rest will not be executed. For that reason, this method loops
244 // during failed allocation attempts. If the java heap becomes exhausted,
245 // we rely on the size_policy object to force a bail out.
246 HeapWord* ParallelScavengeHeap::mem_allocate(
247 size_t size,
248 bool* gc_overhead_limit_was_exceeded) {
249 assert(!SafepointSynchronize::is_at_safepoint(), "should not be at safepoint");
250 assert(Thread::current() != (Thread*)VMThread::vm_thread(), "should not be in vm thread");
251 assert(!Heap_lock->owned_by_self(), "this thread should not own the Heap_lock");
252
253 // In general gc_overhead_limit_was_exceeded should be false so
254 // set it so here and reset it to true only if the gc time
255 // limit is being exceeded as checked below.
256 *gc_overhead_limit_was_exceeded = false;
257
258 HeapWord* result = young_gen()->allocate(size);
259
260 uint loop_count = 0;
261 uint gc_count = 0;
262 uint gclocker_stalled_count = 0;
263
264 while (result == NULL) {
265 // We don't want to have multiple collections for a single filled generation.
266 // To prevent this, each thread tracks the total_collections() value, and if
267 // the count has changed, does not do a new collection.
268 //
269 // The collection count must be read only while holding the heap lock. VM
270 // operations also hold the heap lock during collections. There is a lock
271 // contention case where thread A blocks waiting on the Heap_lock, while
272 // thread B is holding it doing a collection. When thread A gets the lock,
273 // the collection count has already changed. To prevent duplicate collections,
274 // The policy MUST attempt allocations during the same period it reads the
275 // total_collections() value!
276 {
277 MutexLocker ml(Heap_lock);
278 gc_count = total_collections();
279
280 result = young_gen()->allocate(size);
281 if (result != NULL) {
282 return result;
283 }
284
285 // If certain conditions hold, try allocating from the old gen.
286 result = mem_allocate_old_gen(size);
287 if (result != NULL) {
288 return result;
289 }
290
291 if (gclocker_stalled_count > GCLockerRetryAllocationCount) {
292 return NULL;
293 }
294
295 // Failed to allocate without a gc.
296 if (GCLocker::is_active_and_needs_gc()) {
297 // If this thread is not in a jni critical section, we stall
298 // the requestor until the critical section has cleared and
299 // GC allowed. When the critical section clears, a GC is
300 // initiated by the last thread exiting the critical section; so
301 // we retry the allocation sequence from the beginning of the loop,
302 // rather than causing more, now probably unnecessary, GC attempts.
303 JavaThread* jthr = JavaThread::current();
304 if (!jthr->in_critical()) {
305 MutexUnlocker mul(Heap_lock);
306 GCLocker::stall_until_clear();
307 gclocker_stalled_count += 1;
308 continue;
309 } else {
310 if (CheckJNICalls) {
311 fatal("Possible deadlock due to allocating while"
312 " in jni critical section");
313 }
314 return NULL;
315 }
316 }
317 }
318
319 if (result == NULL) {
320 // Generate a VM operation
321 VM_ParallelGCFailedAllocation op(size, gc_count);
322 VMThread::execute(&op);
323
324 // Did the VM operation execute? If so, return the result directly.
325 // This prevents us from looping until time out on requests that can
326 // not be satisfied.
327 if (op.prologue_succeeded()) {
328 assert(is_in_or_null(op.result()), "result not in heap");
329
330 // If GC was locked out during VM operation then retry allocation
331 // and/or stall as necessary.
332 if (op.gc_locked()) {
333 assert(op.result() == NULL, "must be NULL if gc_locked() is true");
334 continue; // retry and/or stall as necessary
335 }
336
337 // Exit the loop if the gc time limit has been exceeded.
338 // The allocation must have failed above ("result" guarding
339 // this path is NULL) and the most recent collection has exceeded the
340 // gc overhead limit (although enough may have been collected to
341 // satisfy the allocation). Exit the loop so that an out-of-memory
342 // will be thrown (return a NULL ignoring the contents of
343 // op.result()),
344 // but clear gc_overhead_limit_exceeded so that the next collection
345 // starts with a clean slate (i.e., forgets about previous overhead
346 // excesses). Fill op.result() with a filler object so that the
347 // heap remains parsable.
348 const bool limit_exceeded = size_policy()->gc_overhead_limit_exceeded();
349 const bool softrefs_clear = soft_ref_policy()->all_soft_refs_clear();
350
351 if (limit_exceeded && softrefs_clear) {
352 *gc_overhead_limit_was_exceeded = true;
353 size_policy()->set_gc_overhead_limit_exceeded(false);
354 log_trace(gc)("ParallelScavengeHeap::mem_allocate: return NULL because gc_overhead_limit_exceeded is set");
355 if (op.result() != NULL) {
356 CollectedHeap::fill_with_object(op.result(), size);
357 }
358 return NULL;
359 }
360
361 return op.result();
362 }
363 }
364
365 // The policy object will prevent us from looping forever. If the
366 // time spent in gc crosses a threshold, we will bail out.
367 loop_count++;
368 if ((result == NULL) && (QueuedAllocationWarningCount > 0) &&
369 (loop_count % QueuedAllocationWarningCount == 0)) {
370 log_warning(gc)("ParallelScavengeHeap::mem_allocate retries %d times", loop_count);
371 log_warning(gc)("\tsize=" SIZE_FORMAT, size);
372 }
373 }
374
375 return result;
376 }
377
378 // A "death march" is a series of ultra-slow allocations in which a full gc is
379 // done before each allocation, and after the full gc the allocation still
380 // cannot be satisfied from the young gen. This routine detects that condition;
381 // it should be called after a full gc has been done and the allocation
382 // attempted from the young gen. The parameter 'addr' should be the result of
383 // that young gen allocation attempt.
384 void
385 ParallelScavengeHeap::death_march_check(HeapWord* const addr, size_t size) {
386 if (addr != NULL) {
387 _death_march_count = 0; // death march has ended
388 } else if (_death_march_count == 0) {
389 if (should_alloc_in_eden(size)) {
390 _death_march_count = 1; // death march has started
391 }
392 }
393 }
394
395 HeapWord* ParallelScavengeHeap::mem_allocate_old_gen(size_t size) {
396 if (!should_alloc_in_eden(size) || GCLocker::is_active_and_needs_gc()) {
397 // Size is too big for eden, or gc is locked out.
398 return old_gen()->allocate(size);
399 }
400
401 // If a "death march" is in progress, allocate from the old gen a limited
402 // number of times before doing a GC.
403 if (_death_march_count > 0) {
404 if (_death_march_count < 64) {
405 ++_death_march_count;
406 return old_gen()->allocate(size);
407 } else {
408 _death_march_count = 0;
409 }
410 }
411 return NULL;
412 }
413
414 void ParallelScavengeHeap::do_full_collection(bool clear_all_soft_refs) {
415 if (UseParallelOldGC) {
416 // The do_full_collection() parameter clear_all_soft_refs
417 // is interpreted here as maximum_compaction which will
418 // cause SoftRefs to be cleared.
419 bool maximum_compaction = clear_all_soft_refs;
420 PSParallelCompact::invoke(maximum_compaction);
421 } else {
422 PSMarkSweepProxy::invoke(clear_all_soft_refs);
423 }
424 }
425
426 // Failed allocation policy. Must be called from the VM thread, and
427 // only at a safepoint! Note that this method has policy for allocation
428 // flow, and NOT collection policy. So we do not check for gc collection
429 // time over limit here, that is the responsibility of the heap specific
430 // collection methods. This method decides where to attempt allocations,
431 // and when to attempt collections, but no collection specific policy.
432 HeapWord* ParallelScavengeHeap::failed_mem_allocate(size_t size) {
433 assert(SafepointSynchronize::is_at_safepoint(), "should be at safepoint");
434 assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread");
435 assert(!is_gc_active(), "not reentrant");
436 assert(!Heap_lock->owned_by_self(), "this thread should not own the Heap_lock");
437
438 // We assume that allocation in eden will fail unless we collect.
439
440 // First level allocation failure, scavenge and allocate in young gen.
441 GCCauseSetter gccs(this, GCCause::_allocation_failure);
442 const bool invoked_full_gc = PSScavenge::invoke();
443 HeapWord* result = young_gen()->allocate(size);
444
445 // Second level allocation failure.
446 // Mark sweep and allocate in young generation.
447 if (result == NULL && !invoked_full_gc) {
448 do_full_collection(false);
449 result = young_gen()->allocate(size);
450 }
451
452 death_march_check(result, size);
453
454 // Third level allocation failure.
455 // After mark sweep and young generation allocation failure,
456 // allocate in old generation.
457 if (result == NULL) {
458 result = old_gen()->allocate(size);
459 }
460
461 // Fourth level allocation failure. We're running out of memory.
462 // More complete mark sweep and allocate in young generation.
463 if (result == NULL) {
464 do_full_collection(true);
465 result = young_gen()->allocate(size);
466 }
467
468 // Fifth level allocation failure.
469 // After more complete mark sweep, allocate in old generation.
470 if (result == NULL) {
471 result = old_gen()->allocate(size);
472 }
473
474 return result;
475 }
476
477 void ParallelScavengeHeap::ensure_parsability(bool retire_tlabs) {
478 CollectedHeap::ensure_parsability(retire_tlabs);
479 young_gen()->eden_space()->ensure_parsability();
480 }
481
482 size_t ParallelScavengeHeap::tlab_capacity(Thread* thr) const {
483 return young_gen()->eden_space()->tlab_capacity(thr);
484 }
485
486 size_t ParallelScavengeHeap::tlab_used(Thread* thr) const {
487 return young_gen()->eden_space()->tlab_used(thr);
488 }
489
490 size_t ParallelScavengeHeap::unsafe_max_tlab_alloc(Thread* thr) const {
491 return young_gen()->eden_space()->unsafe_max_tlab_alloc(thr);
492 }
493
494 HeapWord* ParallelScavengeHeap::allocate_new_tlab(size_t min_size, size_t requested_size, size_t* actual_size) {
495 HeapWord* result = young_gen()->allocate(requested_size);
496 if (result != NULL) {
497 *actual_size = requested_size;
498 }
499
500 return result;
501 }
502
503 void ParallelScavengeHeap::resize_all_tlabs() {
504 CollectedHeap::resize_all_tlabs();
505 }
506
507 // This method is used by System.gc() and JVMTI.
508 void ParallelScavengeHeap::collect(GCCause::Cause cause) {
509 assert(!Heap_lock->owned_by_self(),
510 "this thread should not own the Heap_lock");
511
512 uint gc_count = 0;
513 uint full_gc_count = 0;
514 {
515 MutexLocker ml(Heap_lock);
516 // This value is guarded by the Heap_lock
517 gc_count = total_collections();
518 full_gc_count = total_full_collections();
519 }
520
521 VM_ParallelGCSystemGC op(gc_count, full_gc_count, cause);
522 VMThread::execute(&op);
523 }
524
525 void ParallelScavengeHeap::object_iterate(ObjectClosure* cl) {
526 young_gen()->object_iterate(cl);
527 old_gen()->object_iterate(cl);
528 }
529
530
531 HeapWord* ParallelScavengeHeap::block_start(const void* addr) const {
532 if (young_gen()->is_in_reserved(addr)) {
533 assert(young_gen()->is_in(addr),
534 "addr should be in allocated part of young gen");
535 // called from os::print_location by find or VMError
536 if (Debugging || VMError::fatal_error_in_progress()) return NULL;
537 Unimplemented();
538 } else if (old_gen()->is_in_reserved(addr)) {
539 assert(old_gen()->is_in(addr),
540 "addr should be in allocated part of old gen");
541 return old_gen()->start_array()->object_start((HeapWord*)addr);
542 }
543 return 0;
544 }
545
546 bool ParallelScavengeHeap::block_is_obj(const HeapWord* addr) const {
547 return block_start(addr) == addr;
548 }
549
550 jlong ParallelScavengeHeap::millis_since_last_gc() {
551 return UseParallelOldGC ?
552 PSParallelCompact::millis_since_last_gc() :
553 PSMarkSweepProxy::millis_since_last_gc();
554 }
555
556 void ParallelScavengeHeap::prepare_for_verify() {
557 ensure_parsability(false); // no need to retire TLABs for verification
558 }
559
560 PSHeapSummary ParallelScavengeHeap::create_ps_heap_summary() {
561 PSOldGen* old = old_gen();
562 HeapWord* old_committed_end = (HeapWord*)old->virtual_space()->committed_high_addr();
563 VirtualSpaceSummary old_summary(old->reserved().start(), old_committed_end, old->reserved().end());
564 SpaceSummary old_space(old->reserved().start(), old_committed_end, old->used_in_bytes());
565
566 PSYoungGen* young = young_gen();
567 VirtualSpaceSummary young_summary(young->reserved().start(),
568 (HeapWord*)young->virtual_space()->committed_high_addr(), young->reserved().end());
569
570 MutableSpace* eden = young_gen()->eden_space();
571 SpaceSummary eden_space(eden->bottom(), eden->end(), eden->used_in_bytes());
572
573 MutableSpace* from = young_gen()->from_space();
574 SpaceSummary from_space(from->bottom(), from->end(), from->used_in_bytes());
575
576 MutableSpace* to = young_gen()->to_space();
577 SpaceSummary to_space(to->bottom(), to->end(), to->used_in_bytes());
578
579 VirtualSpaceSummary heap_summary = create_heap_space_summary();
580 return PSHeapSummary(heap_summary, used(), old_summary, old_space, young_summary, eden_space, from_space, to_space);
581 }
582
583 void ParallelScavengeHeap::print_on(outputStream* st) const {
584 young_gen()->print_on(st);
585 old_gen()->print_on(st);
586 MetaspaceUtils::print_on(st);
587 }
588
589 void ParallelScavengeHeap::print_on_error(outputStream* st) const {
590 this->CollectedHeap::print_on_error(st);
591
592 if (UseParallelOldGC) {
593 st->cr();
594 PSParallelCompact::print_on_error(st);
595 }
596 }
597
598 void ParallelScavengeHeap::gc_threads_do(ThreadClosure* tc) const {
599 PSScavenge::gc_task_manager()->threads_do(tc);
600 }
601
602 void ParallelScavengeHeap::print_gc_threads_on(outputStream* st) const {
603 PSScavenge::gc_task_manager()->print_threads_on(st);
604 }
605
606 void ParallelScavengeHeap::print_tracing_info() const {
607 AdaptiveSizePolicyOutput::print();
608 log_debug(gc, heap, exit)("Accumulated young generation GC time %3.7f secs", PSScavenge::accumulated_time()->seconds());
609 log_debug(gc, heap, exit)("Accumulated old generation GC time %3.7f secs",
610 UseParallelOldGC ? PSParallelCompact::accumulated_time()->seconds() : PSMarkSweepProxy::accumulated_time()->seconds());
611 }
612
613
614 void ParallelScavengeHeap::verify(VerifyOption option /* ignored */) {
615 // Why do we need the total_collections()-filter below?
616 if (total_collections() > 0) {
617 log_debug(gc, verify)("Tenured");
618 old_gen()->verify();
619
620 log_debug(gc, verify)("Eden");
621 young_gen()->verify();
622 }
623 }
624
625 void ParallelScavengeHeap::trace_heap(GCWhen::Type when, const GCTracer* gc_tracer) {
626 const PSHeapSummary& heap_summary = create_ps_heap_summary();
627 gc_tracer->report_gc_heap_summary(when, heap_summary);
628
629 const MetaspaceSummary& metaspace_summary = create_metaspace_summary();
630 gc_tracer->report_metaspace_summary(when, metaspace_summary);
631 }
632
633 ParallelScavengeHeap* ParallelScavengeHeap::heap() {
634 CollectedHeap* heap = Universe::heap();
635 assert(heap != NULL, "Uninitialized access to ParallelScavengeHeap::heap()");
636 assert(heap->kind() == CollectedHeap::Parallel, "Invalid name");
637 return (ParallelScavengeHeap*)heap;
638 }
639
640 CardTableBarrierSet* ParallelScavengeHeap::barrier_set() {
641 return barrier_set_cast<CardTableBarrierSet>(BarrierSet::barrier_set());
642 }
643
644 PSCardTable* ParallelScavengeHeap::card_table() {
645 return static_cast<PSCardTable*>(barrier_set()->card_table());
646 }
647
648 // Before delegating the resize to the young generation,
649 // the reserved space for the young and old generations
650 // may be changed to accommodate the desired resize.
651 void ParallelScavengeHeap::resize_young_gen(size_t eden_size,
652 size_t survivor_size) {
653 if (UseAdaptiveGCBoundary) {
654 if (size_policy()->bytes_absorbed_from_eden() != 0) {
655 size_policy()->reset_bytes_absorbed_from_eden();
656 return; // The generation changed size already.
657 }
658 gens()->adjust_boundary_for_young_gen_needs(eden_size, survivor_size);
659 }
660
661 // Delegate the resize to the generation.
662 _young_gen->resize(eden_size, survivor_size);
663 }
664
665 // Before delegating the resize to the old generation,
666 // the reserved space for the young and old generations
667 // may be changed to accommodate the desired resize.
668 void ParallelScavengeHeap::resize_old_gen(size_t desired_free_space) {
669 if (UseAdaptiveGCBoundary) {
670 if (size_policy()->bytes_absorbed_from_eden() != 0) {
671 size_policy()->reset_bytes_absorbed_from_eden();
672 return; // The generation changed size already.
673 }
674 gens()->adjust_boundary_for_old_gen_needs(desired_free_space);
675 }
676
677 // Delegate the resize to the generation.
678 _old_gen->resize(desired_free_space);
679 }
680
681 ParallelScavengeHeap::ParStrongRootsScope::ParStrongRootsScope() {
682 // nothing particular
683 }
684
685 ParallelScavengeHeap::ParStrongRootsScope::~ParStrongRootsScope() {
686 // nothing particular
687 }
688
689 #ifndef PRODUCT
690 void ParallelScavengeHeap::record_gen_tops_before_GC() {
691 if (ZapUnusedHeapArea) {
692 young_gen()->record_spaces_top();
693 old_gen()->record_spaces_top();
694 }
695 }
696
697 void ParallelScavengeHeap::gen_mangle_unused_area() {
698 if (ZapUnusedHeapArea) {
699 young_gen()->eden_space()->mangle_unused_area();
700 young_gen()->to_space()->mangle_unused_area();
701 young_gen()->from_space()->mangle_unused_area();
702 old_gen()->object_space()->mangle_unused_area();
703 }
704 }
705 #endif
706
707 void ParallelScavengeHeap::register_nmethod(nmethod* nm) {
708 ScavengableNMethods::register_nmethod(nm);
709 }
710
711 void ParallelScavengeHeap::unregister_nmethod(nmethod* nm) {
712 ScavengableNMethods::unregister_nmethod(nm);
713 }
714
715 void ParallelScavengeHeap::verify_nmethod(nmethod* nm) {
716 ScavengableNMethods::verify_nmethod(nm);
717 }
718
719 void ParallelScavengeHeap::flush_nmethod(nmethod* nm) {
720 // nothing particular
721 }
722
723 void ParallelScavengeHeap::prune_scavengable_nmethods() {
724 ScavengableNMethods::prune_nmethods();
725 }
726
727 GrowableArray<GCMemoryManager*> ParallelScavengeHeap::memory_managers() {
728 GrowableArray<GCMemoryManager*> memory_managers(2);
729 memory_managers.append(_young_manager);
730 memory_managers.append(_old_manager);
731 return memory_managers;
732 }
733
734 GrowableArray<MemoryPool*> ParallelScavengeHeap::memory_pools() {
735 GrowableArray<MemoryPool*> memory_pools(3);
736 memory_pools.append(_eden_pool);
737 memory_pools.append(_survivor_pool);
738 memory_pools.append(_old_pool);
739 return memory_pools;
740 }