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