1 /*
2 * Copyright (c) 2001, 2015, 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/adjoiningGenerations.hpp"
27 #include "gc/parallel/adjoiningVirtualSpaces.hpp"
28 #include "gc/parallel/cardTableExtension.hpp"
29 #include "gc/parallel/gcTaskManager.hpp"
30 #include "gc/parallel/generationSizer.hpp"
31 #include "gc/parallel/parallelScavengeHeap.inline.hpp"
32 #include "gc/parallel/psAdaptiveSizePolicy.hpp"
33 #include "gc/parallel/psMarkSweep.hpp"
34 #include "gc/parallel/psParallelCompact.hpp"
35 #include "gc/parallel/psPromotionManager.hpp"
36 #include "gc/parallel/psScavenge.hpp"
37 #include "gc/parallel/vmPSOperations.hpp"
38 #include "gc/shared/gcHeapSummary.hpp"
39 #include "gc/shared/gcLocker.inline.hpp"
40 #include "gc/shared/gcWhen.hpp"
41 #include "oops/oop.inline.hpp"
42 #include "runtime/handles.inline.hpp"
43 #include "runtime/java.hpp"
44 #include "runtime/vmThread.hpp"
45 #include "services/memTracker.hpp"
46 #include "utilities/vmError.hpp"
47
48 PSYoungGen* ParallelScavengeHeap::_young_gen = NULL;
49 PSOldGen* ParallelScavengeHeap::_old_gen = NULL;
50 PSAdaptiveSizePolicy* ParallelScavengeHeap::_size_policy = NULL;
51 PSGCAdaptivePolicyCounters* ParallelScavengeHeap::_gc_policy_counters = NULL;
52 GCTaskManager* ParallelScavengeHeap::_gc_task_manager = NULL;
53
54 jint ParallelScavengeHeap::initialize() {
55 CollectedHeap::pre_initialize();
56
57 const size_t heap_size = _collector_policy->max_heap_byte_size();
58
59 ReservedSpace heap_rs = Universe::reserve_heap(heap_size, _collector_policy->heap_alignment());
60
61 os::trace_page_sizes("ps main", _collector_policy->min_heap_byte_size(),
62 heap_size, generation_alignment(),
63 heap_rs.base(),
64 heap_rs.size());
65
66 initialize_reserved_region((HeapWord*)heap_rs.base(), (HeapWord*)(heap_rs.base() + heap_rs.size()));
67
68 CardTableExtension* const barrier_set = new CardTableExtension(reserved_region());
69 barrier_set->initialize();
70 set_barrier_set(barrier_set);
71
72 // Make up the generations
73 // Calculate the maximum size that a generation can grow. This
74 // includes growth into the other generation. Note that the
75 // parameter _max_gen_size is kept as the maximum
76 // size of the generation as the boundaries currently stand.
77 // _max_gen_size is still used as that value.
78 double max_gc_pause_sec = ((double) MaxGCPauseMillis)/1000.0;
79 double max_gc_minor_pause_sec = ((double) MaxGCMinorPauseMillis)/1000.0;
80
81 _gens = new AdjoiningGenerations(heap_rs, _collector_policy, generation_alignment());
82
83 _old_gen = _gens->old_gen();
84 _young_gen = _gens->young_gen();
85
86 const size_t eden_capacity = _young_gen->eden_space()->capacity_in_bytes();
87 const size_t old_capacity = _old_gen->capacity_in_bytes();
88 const size_t initial_promo_size = MIN2(eden_capacity, old_capacity);
89 _size_policy =
90 new PSAdaptiveSizePolicy(eden_capacity,
91 initial_promo_size,
92 young_gen()->to_space()->capacity_in_bytes(),
93 _collector_policy->gen_alignment(),
94 max_gc_pause_sec,
95 max_gc_minor_pause_sec,
96 GCTimeRatio
97 );
98
99 assert(!UseAdaptiveGCBoundary ||
100 (old_gen()->virtual_space()->high_boundary() ==
101 young_gen()->virtual_space()->low_boundary()),
102 "Boundaries must meet");
103 // initialize the policy counters - 2 collectors, 3 generations
104 _gc_policy_counters =
105 new PSGCAdaptivePolicyCounters("ParScav:MSC", 2, 3, _size_policy);
106
107 // Set up the GCTaskManager
108 _gc_task_manager = GCTaskManager::create(ParallelGCThreads);
109
110 if (UseParallelOldGC && !PSParallelCompact::initialize()) {
111 return JNI_ENOMEM;
112 }
113
114 return JNI_OK;
115 }
116
117 void ParallelScavengeHeap::post_initialize() {
118 // Need to init the tenuring threshold
119 PSScavenge::initialize();
120 if (UseParallelOldGC) {
121 PSParallelCompact::post_initialize();
122 } else {
123 PSMarkSweep::initialize();
124 }
125 PSPromotionManager::initialize();
126 }
127
128 void ParallelScavengeHeap::update_counters() {
129 young_gen()->update_counters();
130 old_gen()->update_counters();
131 MetaspaceCounters::update_performance_counters();
132 CompressedClassSpaceCounters::update_performance_counters();
133 }
134
135 size_t ParallelScavengeHeap::capacity() const {
136 size_t value = young_gen()->capacity_in_bytes() + old_gen()->capacity_in_bytes();
137 return value;
138 }
139
140 size_t ParallelScavengeHeap::used() const {
141 size_t value = young_gen()->used_in_bytes() + old_gen()->used_in_bytes();
142 return value;
143 }
144
145 bool ParallelScavengeHeap::is_maximal_no_gc() const {
146 return old_gen()->is_maximal_no_gc() && young_gen()->is_maximal_no_gc();
147 }
148
149
150 size_t ParallelScavengeHeap::max_capacity() const {
151 size_t estimated = reserved_region().byte_size();
152 if (UseAdaptiveSizePolicy) {
153 estimated -= _size_policy->max_survivor_size(young_gen()->max_size());
154 } else {
155 estimated -= young_gen()->to_space()->capacity_in_bytes();
156 }
157 return MAX2(estimated, capacity());
158 }
159
160 bool ParallelScavengeHeap::is_in(const void* p) const {
161 return young_gen()->is_in(p) || old_gen()->is_in(p);
162 }
163
164 bool ParallelScavengeHeap::is_in_reserved(const void* p) const {
165 return young_gen()->is_in_reserved(p) || old_gen()->is_in_reserved(p);
166 }
167
168 bool ParallelScavengeHeap::is_scavengable(const void* addr) {
169 return is_in_young((oop)addr);
170 }
171
172 // There are two levels of allocation policy here.
173 //
174 // When an allocation request fails, the requesting thread must invoke a VM
175 // operation, transfer control to the VM thread, and await the results of a
176 // garbage collection. That is quite expensive, and we should avoid doing it
177 // multiple times if possible.
178 //
179 // To accomplish this, we have a basic allocation policy, and also a
180 // failed allocation policy.
181 //
182 // The basic allocation policy controls how you allocate memory without
183 // attempting garbage collection. It is okay to grab locks and
184 // expand the heap, if that can be done without coming to a safepoint.
185 // It is likely that the basic allocation policy will not be very
186 // aggressive.
187 //
188 // The failed allocation policy is invoked from the VM thread after
189 // the basic allocation policy is unable to satisfy a mem_allocate
190 // request. This policy needs to cover the entire range of collection,
191 // heap expansion, and out-of-memory conditions. It should make every
192 // attempt to allocate the requested memory.
193
194 // Basic allocation policy. Should never be called at a safepoint, or
195 // from the VM thread.
196 //
197 // This method must handle cases where many mem_allocate requests fail
198 // simultaneously. When that happens, only one VM operation will succeed,
199 // and the rest will not be executed. For that reason, this method loops
200 // during failed allocation attempts. If the java heap becomes exhausted,
201 // we rely on the size_policy object to force a bail out.
202 HeapWord* ParallelScavengeHeap::mem_allocate(
203 size_t size,
204 bool* gc_overhead_limit_was_exceeded) {
205 assert(!SafepointSynchronize::is_at_safepoint(), "should not be at safepoint");
206 assert(Thread::current() != (Thread*)VMThread::vm_thread(), "should not be in vm thread");
207 assert(!Heap_lock->owned_by_self(), "this thread should not own the Heap_lock");
208
209 // In general gc_overhead_limit_was_exceeded should be false so
210 // set it so here and reset it to true only if the gc time
211 // limit is being exceeded as checked below.
212 *gc_overhead_limit_was_exceeded = false;
213
214 HeapWord* result = young_gen()->allocate(size);
215
216 uint loop_count = 0;
217 uint gc_count = 0;
218 uint gclocker_stalled_count = 0;
219
220 while (result == NULL) {
221 // We don't want to have multiple collections for a single filled generation.
222 // To prevent this, each thread tracks the total_collections() value, and if
223 // the count has changed, does not do a new collection.
224 //
225 // The collection count must be read only while holding the heap lock. VM
226 // operations also hold the heap lock during collections. There is a lock
227 // contention case where thread A blocks waiting on the Heap_lock, while
228 // thread B is holding it doing a collection. When thread A gets the lock,
229 // the collection count has already changed. To prevent duplicate collections,
230 // The policy MUST attempt allocations during the same period it reads the
231 // total_collections() value!
232 {
233 MutexLocker ml(Heap_lock);
234 gc_count = total_collections();
235
236 result = young_gen()->allocate(size);
237 if (result != NULL) {
238 return result;
239 }
240
241 // If certain conditions hold, try allocating from the old gen.
242 result = mem_allocate_old_gen(size);
243 if (result != NULL) {
244 return result;
245 }
246
247 if (gclocker_stalled_count > GCLockerRetryAllocationCount) {
248 return NULL;
249 }
250
251 // Failed to allocate without a gc.
252 if (GC_locker::is_active_and_needs_gc()) {
253 // If this thread is not in a jni critical section, we stall
254 // the requestor until the critical section has cleared and
255 // GC allowed. When the critical section clears, a GC is
256 // initiated by the last thread exiting the critical section; so
257 // we retry the allocation sequence from the beginning of the loop,
258 // rather than causing more, now probably unnecessary, GC attempts.
259 JavaThread* jthr = JavaThread::current();
260 if (!jthr->in_critical()) {
261 MutexUnlocker mul(Heap_lock);
262 GC_locker::stall_until_clear();
263 gclocker_stalled_count += 1;
264 continue;
265 } else {
266 if (CheckJNICalls) {
267 fatal("Possible deadlock due to allocating while"
268 " in jni critical section");
269 }
270 return NULL;
271 }
272 }
273 }
274
275 if (result == NULL) {
276 // Generate a VM operation
277 VM_ParallelGCFailedAllocation op(size, gc_count);
278 VMThread::execute(&op);
279
280 // Did the VM operation execute? If so, return the result directly.
281 // This prevents us from looping until time out on requests that can
282 // not be satisfied.
283 if (op.prologue_succeeded()) {
284 assert(is_in_or_null(op.result()), "result not in heap");
285
286 // If GC was locked out during VM operation then retry allocation
287 // and/or stall as necessary.
288 if (op.gc_locked()) {
289 assert(op.result() == NULL, "must be NULL if gc_locked() is true");
290 continue; // retry and/or stall as necessary
291 }
292
293 // Exit the loop if the gc time limit has been exceeded.
294 // The allocation must have failed above ("result" guarding
295 // this path is NULL) and the most recent collection has exceeded the
296 // gc overhead limit (although enough may have been collected to
297 // satisfy the allocation). Exit the loop so that an out-of-memory
298 // will be thrown (return a NULL ignoring the contents of
299 // op.result()),
300 // but clear gc_overhead_limit_exceeded so that the next collection
301 // starts with a clean slate (i.e., forgets about previous overhead
302 // excesses). Fill op.result() with a filler object so that the
303 // heap remains parsable.
304 const bool limit_exceeded = size_policy()->gc_overhead_limit_exceeded();
305 const bool softrefs_clear = collector_policy()->all_soft_refs_clear();
306
307 if (limit_exceeded && softrefs_clear) {
308 *gc_overhead_limit_was_exceeded = true;
309 size_policy()->set_gc_overhead_limit_exceeded(false);
310 if (PrintGCDetails && Verbose) {
311 gclog_or_tty->print_cr("ParallelScavengeHeap::mem_allocate: "
312 "return NULL because gc_overhead_limit_exceeded is set");
313 }
314 if (op.result() != NULL) {
315 CollectedHeap::fill_with_object(op.result(), size);
316 }
317 return NULL;
318 }
319
320 return op.result();
321 }
322 }
323
324 // The policy object will prevent us from looping forever. If the
325 // time spent in gc crosses a threshold, we will bail out.
326 loop_count++;
327 if ((result == NULL) && (QueuedAllocationWarningCount > 0) &&
328 (loop_count % QueuedAllocationWarningCount == 0)) {
329 warning("ParallelScavengeHeap::mem_allocate retries %d times \n\t"
330 " size=" SIZE_FORMAT, loop_count, size);
331 }
332 }
333
334 return result;
335 }
336
337 // A "death march" is a series of ultra-slow allocations in which a full gc is
338 // done before each allocation, and after the full gc the allocation still
339 // cannot be satisfied from the young gen. This routine detects that condition;
340 // it should be called after a full gc has been done and the allocation
341 // attempted from the young gen. The parameter 'addr' should be the result of
342 // that young gen allocation attempt.
343 void
344 ParallelScavengeHeap::death_march_check(HeapWord* const addr, size_t size) {
345 if (addr != NULL) {
346 _death_march_count = 0; // death march has ended
347 } else if (_death_march_count == 0) {
348 if (should_alloc_in_eden(size)) {
349 _death_march_count = 1; // death march has started
350 }
351 }
352 }
353
354 HeapWord* ParallelScavengeHeap::mem_allocate_old_gen(size_t size) {
355 if (!should_alloc_in_eden(size) || GC_locker::is_active_and_needs_gc()) {
356 // Size is too big for eden, or gc is locked out.
357 return old_gen()->allocate(size);
358 }
359
360 // If a "death march" is in progress, allocate from the old gen a limited
361 // number of times before doing a GC.
362 if (_death_march_count > 0) {
363 if (_death_march_count < 64) {
364 ++_death_march_count;
365 return old_gen()->allocate(size);
366 } else {
367 _death_march_count = 0;
368 }
369 }
370 return NULL;
371 }
372
373 void ParallelScavengeHeap::do_full_collection(bool clear_all_soft_refs) {
374 if (UseParallelOldGC) {
375 // The do_full_collection() parameter clear_all_soft_refs
376 // is interpreted here as maximum_compaction which will
377 // cause SoftRefs to be cleared.
378 bool maximum_compaction = clear_all_soft_refs;
379 PSParallelCompact::invoke(maximum_compaction);
380 } else {
381 PSMarkSweep::invoke(clear_all_soft_refs);
382 }
383 }
384
385 // Failed allocation policy. Must be called from the VM thread, and
386 // only at a safepoint! Note that this method has policy for allocation
387 // flow, and NOT collection policy. So we do not check for gc collection
388 // time over limit here, that is the responsibility of the heap specific
389 // collection methods. This method decides where to attempt allocations,
390 // and when to attempt collections, but no collection specific policy.
391 HeapWord* ParallelScavengeHeap::failed_mem_allocate(size_t size) {
392 assert(SafepointSynchronize::is_at_safepoint(), "should be at safepoint");
393 assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread");
394 assert(!is_gc_active(), "not reentrant");
395 assert(!Heap_lock->owned_by_self(), "this thread should not own the Heap_lock");
396
397 // We assume that allocation in eden will fail unless we collect.
398
399 // First level allocation failure, scavenge and allocate in young gen.
400 GCCauseSetter gccs(this, GCCause::_allocation_failure);
401 const bool invoked_full_gc = PSScavenge::invoke();
402 HeapWord* result = young_gen()->allocate(size);
403
404 // Second level allocation failure.
405 // Mark sweep and allocate in young generation.
406 if (result == NULL && !invoked_full_gc) {
407 do_full_collection(false);
408 result = young_gen()->allocate(size);
409 }
410
411 death_march_check(result, size);
412
413 // Third level allocation failure.
414 // After mark sweep and young generation allocation failure,
415 // allocate in old generation.
416 if (result == NULL) {
417 result = old_gen()->allocate(size);
418 }
419
420 // Fourth level allocation failure. We're running out of memory.
421 // More complete mark sweep and allocate in young generation.
422 if (result == NULL) {
423 do_full_collection(true);
424 result = young_gen()->allocate(size);
425 }
426
427 // Fifth level allocation failure.
428 // After more complete mark sweep, allocate in old generation.
429 if (result == NULL) {
430 result = old_gen()->allocate(size);
431 }
432
433 return result;
434 }
435
436 void ParallelScavengeHeap::ensure_parsability(bool retire_tlabs) {
437 CollectedHeap::ensure_parsability(retire_tlabs);
438 young_gen()->eden_space()->ensure_parsability();
439 }
440
441 size_t ParallelScavengeHeap::tlab_capacity(Thread* thr) const {
442 return young_gen()->eden_space()->tlab_capacity(thr);
443 }
444
445 size_t ParallelScavengeHeap::tlab_used(Thread* thr) const {
446 return young_gen()->eden_space()->tlab_used(thr);
447 }
448
449 size_t ParallelScavengeHeap::unsafe_max_tlab_alloc(Thread* thr) const {
450 return young_gen()->eden_space()->unsafe_max_tlab_alloc(thr);
451 }
452
453 HeapWord* ParallelScavengeHeap::allocate_new_tlab(size_t size) {
454 return young_gen()->allocate(size);
455 }
456
457 void ParallelScavengeHeap::accumulate_statistics_all_tlabs() {
458 CollectedHeap::accumulate_statistics_all_tlabs();
459 }
460
461 void ParallelScavengeHeap::resize_all_tlabs() {
462 CollectedHeap::resize_all_tlabs();
463 }
464
465 bool ParallelScavengeHeap::can_elide_initializing_store_barrier(oop new_obj) {
466 // We don't need barriers for stores to objects in the
467 // young gen and, a fortiori, for initializing stores to
468 // objects therein.
469 return is_in_young(new_obj);
470 }
471
472 // This method is used by System.gc() and JVMTI.
473 void ParallelScavengeHeap::collect(GCCause::Cause cause) {
474 assert(!Heap_lock->owned_by_self(),
475 "this thread should not own the Heap_lock");
476
477 uint gc_count = 0;
478 uint full_gc_count = 0;
479 {
480 MutexLocker ml(Heap_lock);
481 // This value is guarded by the Heap_lock
482 gc_count = total_collections();
483 full_gc_count = total_full_collections();
484 }
485
486 VM_ParallelGCSystemGC op(gc_count, full_gc_count, cause);
487 VMThread::execute(&op);
488 }
489
490 void ParallelScavengeHeap::object_iterate(ObjectClosure* cl) {
491 young_gen()->object_iterate(cl);
492 old_gen()->object_iterate(cl);
493 }
494
495
496 HeapWord* ParallelScavengeHeap::block_start(const void* addr) const {
497 if (young_gen()->is_in_reserved(addr)) {
498 assert(young_gen()->is_in(addr),
499 "addr should be in allocated part of young gen");
500 // called from os::print_location by find or VMError
501 if (Debugging || VMError::fatal_error_in_progress()) return NULL;
502 Unimplemented();
503 } else if (old_gen()->is_in_reserved(addr)) {
504 assert(old_gen()->is_in(addr),
505 "addr should be in allocated part of old gen");
506 return old_gen()->start_array()->object_start((HeapWord*)addr);
507 }
508 return 0;
509 }
510
511 size_t ParallelScavengeHeap::block_size(const HeapWord* addr) const {
512 return oop(addr)->size();
513 }
514
515 bool ParallelScavengeHeap::block_is_obj(const HeapWord* addr) const {
516 return block_start(addr) == addr;
517 }
518
519 jlong ParallelScavengeHeap::millis_since_last_gc() {
520 return UseParallelOldGC ?
521 PSParallelCompact::millis_since_last_gc() :
522 PSMarkSweep::millis_since_last_gc();
523 }
524
525 void ParallelScavengeHeap::prepare_for_verify() {
526 ensure_parsability(false); // no need to retire TLABs for verification
527 }
528
529 PSHeapSummary ParallelScavengeHeap::create_ps_heap_summary() {
530 PSOldGen* old = old_gen();
531 HeapWord* old_committed_end = (HeapWord*)old->virtual_space()->committed_high_addr();
532 VirtualSpaceSummary old_summary(old->reserved().start(), old_committed_end, old->reserved().end());
533 SpaceSummary old_space(old->reserved().start(), old_committed_end, old->used_in_bytes());
534
535 PSYoungGen* young = young_gen();
536 VirtualSpaceSummary young_summary(young->reserved().start(),
537 (HeapWord*)young->virtual_space()->committed_high_addr(), young->reserved().end());
538
539 MutableSpace* eden = young_gen()->eden_space();
540 SpaceSummary eden_space(eden->bottom(), eden->end(), eden->used_in_bytes());
541
542 MutableSpace* from = young_gen()->from_space();
543 SpaceSummary from_space(from->bottom(), from->end(), from->used_in_bytes());
544
545 MutableSpace* to = young_gen()->to_space();
546 SpaceSummary to_space(to->bottom(), to->end(), to->used_in_bytes());
547
548 VirtualSpaceSummary heap_summary = create_heap_space_summary();
549 return PSHeapSummary(heap_summary, used(), old_summary, old_space, young_summary, eden_space, from_space, to_space);
550 }
551
552 void ParallelScavengeHeap::print_on(outputStream* st) const {
553 young_gen()->print_on(st);
554 old_gen()->print_on(st);
555 MetaspaceAux::print_on(st);
556 }
557
558 void ParallelScavengeHeap::print_on_error(outputStream* st) const {
559 this->CollectedHeap::print_on_error(st);
560
561 if (UseParallelOldGC) {
562 st->cr();
563 PSParallelCompact::print_on_error(st);
564 }
565 }
566
567 void ParallelScavengeHeap::gc_threads_do(ThreadClosure* tc) const {
568 PSScavenge::gc_task_manager()->threads_do(tc);
569 }
570
571 void ParallelScavengeHeap::print_gc_threads_on(outputStream* st) const {
572 PSScavenge::gc_task_manager()->print_threads_on(st);
573 }
574
575 void ParallelScavengeHeap::print_tracing_info() const {
576 if (TraceYoungGenTime) {
577 double time = PSScavenge::accumulated_time()->seconds();
578 tty->print_cr("[Accumulated GC generation 0 time %3.7f secs]", time);
579 }
580 if (TraceOldGenTime) {
581 double time = UseParallelOldGC ? PSParallelCompact::accumulated_time()->seconds() : PSMarkSweep::accumulated_time()->seconds();
582 tty->print_cr("[Accumulated GC generation 1 time %3.7f secs]", time);
583 }
584 }
585
586
587 void ParallelScavengeHeap::verify(bool silent, VerifyOption option /* ignored */) {
588 // Why do we need the total_collections()-filter below?
589 if (total_collections() > 0) {
590 if (!silent) {
591 gclog_or_tty->print("tenured ");
592 }
593 old_gen()->verify();
594
595 if (!silent) {
596 gclog_or_tty->print("eden ");
597 }
598 young_gen()->verify();
599 }
600 }
601
602 void ParallelScavengeHeap::print_heap_change(size_t prev_used) {
603 if (PrintGCDetails && Verbose) {
604 gclog_or_tty->print(" " SIZE_FORMAT
605 "->" SIZE_FORMAT
606 "(" SIZE_FORMAT ")",
607 prev_used, used(), capacity());
608 } else {
609 gclog_or_tty->print(" " SIZE_FORMAT "K"
610 "->" SIZE_FORMAT "K"
611 "(" SIZE_FORMAT "K)",
612 prev_used / K, used() / K, capacity() / K);
613 }
614 }
615
616 void ParallelScavengeHeap::trace_heap(GCWhen::Type when, const GCTracer* gc_tracer) {
617 const PSHeapSummary& heap_summary = create_ps_heap_summary();
618 gc_tracer->report_gc_heap_summary(when, heap_summary);
619
620 const MetaspaceSummary& metaspace_summary = create_metaspace_summary();
621 gc_tracer->report_metaspace_summary(when, metaspace_summary);
622 }
623
624 ParallelScavengeHeap* ParallelScavengeHeap::heap() {
625 CollectedHeap* heap = Universe::heap();
626 assert(heap != NULL, "Uninitialized access to ParallelScavengeHeap::heap()");
627 assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Not a ParallelScavengeHeap");
628 return (ParallelScavengeHeap*)heap;
629 }
630
631 // Before delegating the resize to the young generation,
632 // the reserved space for the young and old generations
633 // may be changed to accommodate the desired resize.
634 void ParallelScavengeHeap::resize_young_gen(size_t eden_size,
635 size_t survivor_size) {
636 if (UseAdaptiveGCBoundary) {
637 if (size_policy()->bytes_absorbed_from_eden() != 0) {
638 size_policy()->reset_bytes_absorbed_from_eden();
639 return; // The generation changed size already.
640 }
641 gens()->adjust_boundary_for_young_gen_needs(eden_size, survivor_size);
642 }
643
644 // Delegate the resize to the generation.
645 _young_gen->resize(eden_size, survivor_size);
646 }
647
648 // Before delegating the resize to the old generation,
649 // the reserved space for the young and old generations
650 // may be changed to accommodate the desired resize.
651 void ParallelScavengeHeap::resize_old_gen(size_t desired_free_space) {
652 if (UseAdaptiveGCBoundary) {
653 if (size_policy()->bytes_absorbed_from_eden() != 0) {
654 size_policy()->reset_bytes_absorbed_from_eden();
655 return; // The generation changed size already.
656 }
657 gens()->adjust_boundary_for_old_gen_needs(desired_free_space);
658 }
659
660 // Delegate the resize to the generation.
661 _old_gen->resize(desired_free_space);
662 }
663
664 ParallelScavengeHeap::ParStrongRootsScope::ParStrongRootsScope() {
665 // nothing particular
666 }
667
668 ParallelScavengeHeap::ParStrongRootsScope::~ParStrongRootsScope() {
669 // nothing particular
670 }
671
672 #ifndef PRODUCT
673 void ParallelScavengeHeap::record_gen_tops_before_GC() {
674 if (ZapUnusedHeapArea) {
675 young_gen()->record_spaces_top();
676 old_gen()->record_spaces_top();
677 }
678 }
679
680 void ParallelScavengeHeap::gen_mangle_unused_area() {
681 if (ZapUnusedHeapArea) {
682 young_gen()->eden_space()->mangle_unused_area();
683 young_gen()->to_space()->mangle_unused_area();
684 young_gen()->from_space()->mangle_unused_area();
685 old_gen()->object_space()->mangle_unused_area();
686 }
687 }
688 #endif