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