1 /*
2 * Copyright (c) 2001, 2017, 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 CollectedHeap::pre_initialize();
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
66 os::trace_page_sizes("Heap",
67 _collector_policy->min_heap_byte_size(),
68 heap_size,
69 generation_alignment(),
70 heap_rs.base(),
71 heap_rs.size());
72
73 initialize_reserved_region((HeapWord*)heap_rs.base(), (HeapWord*)(heap_rs.base() + heap_rs.size()));
74
75 CardTableExtension* const barrier_set = new CardTableExtension(reserved_region());
76 barrier_set->initialize();
77 set_barrier_set(barrier_set);
78
79 // Make up the generations
80 // Calculate the maximum size that a generation can grow. This
81 // includes growth into the other generation. Note that the
82 // parameter _max_gen_size is kept as the maximum
83 // size of the generation as the boundaries currently stand.
84 // _max_gen_size is still used as that value.
85 double max_gc_pause_sec = ((double) MaxGCPauseMillis)/1000.0;
86 double max_gc_minor_pause_sec = ((double) MaxGCMinorPauseMillis)/1000.0;
87
88 _gens = new AdjoiningGenerations(heap_rs, _collector_policy, generation_alignment());
89
90 _old_gen = _gens->old_gen();
91 _young_gen = _gens->young_gen();
92
93 const size_t eden_capacity = _young_gen->eden_space()->capacity_in_bytes();
94 const size_t old_capacity = _old_gen->capacity_in_bytes();
95 const size_t initial_promo_size = MIN2(eden_capacity, old_capacity);
96 _size_policy =
97 new PSAdaptiveSizePolicy(eden_capacity,
98 initial_promo_size,
99 young_gen()->to_space()->capacity_in_bytes(),
100 _collector_policy->gen_alignment(),
101 max_gc_pause_sec,
102 max_gc_minor_pause_sec,
103 GCTimeRatio
104 );
105
106 assert(!UseAdaptiveGCBoundary ||
107 (old_gen()->virtual_space()->high_boundary() ==
108 young_gen()->virtual_space()->low_boundary()),
109 "Boundaries must meet");
110 // initialize the policy counters - 2 collectors, 3 generations
111 _gc_policy_counters =
112 new PSGCAdaptivePolicyCounters("ParScav:MSC", 2, 3, _size_policy);
113
114 // Set up the GCTaskManager
115 _gc_task_manager = GCTaskManager::create(ParallelGCThreads);
116
117 if (UseParallelOldGC && !PSParallelCompact::initialize()) {
118 return JNI_ENOMEM;
119 }
120
121 return JNI_OK;
122 }
123
124 void ParallelScavengeHeap::post_initialize() {
125 // Need to init the tenuring threshold
126 PSScavenge::initialize();
127 if (UseParallelOldGC) {
128 PSParallelCompact::post_initialize();
129 } else {
130 PSMarkSweep::initialize();
131 }
132 PSPromotionManager::initialize();
133 }
134
135 void ParallelScavengeHeap::update_counters() {
136 young_gen()->update_counters();
137 old_gen()->update_counters();
138 MetaspaceCounters::update_performance_counters();
139 CompressedClassSpaceCounters::update_performance_counters();
140 }
141
142 size_t ParallelScavengeHeap::capacity() const {
143 size_t value = young_gen()->capacity_in_bytes() + old_gen()->capacity_in_bytes();
144 return value;
145 }
146
147 size_t ParallelScavengeHeap::used() const {
148 size_t value = young_gen()->used_in_bytes() + old_gen()->used_in_bytes();
149 return value;
150 }
151
152 bool ParallelScavengeHeap::is_maximal_no_gc() const {
153 return old_gen()->is_maximal_no_gc() && young_gen()->is_maximal_no_gc();
154 }
155
156
157 size_t ParallelScavengeHeap::max_capacity() const {
158 size_t estimated = reserved_region().byte_size();
159 if (UseAdaptiveSizePolicy) {
160 estimated -= _size_policy->max_survivor_size(young_gen()->max_size());
161 } else {
162 estimated -= young_gen()->to_space()->capacity_in_bytes();
163 }
164 return MAX2(estimated, capacity());
165 }
166
167 bool ParallelScavengeHeap::is_in(const void* p) const {
168 return young_gen()->is_in(p) || old_gen()->is_in(p);
169 }
170
171 bool ParallelScavengeHeap::is_in_reserved(const void* p) const {
172 return young_gen()->is_in_reserved(p) || old_gen()->is_in_reserved(p);
173 }
174
175 // There are two levels of allocation policy here.
176 //
177 // When an allocation request fails, the requesting thread must invoke a VM
178 // operation, transfer control to the VM thread, and await the results of a
179 // garbage collection. That is quite expensive, and we should avoid doing it
180 // multiple times if possible.
181 //
182 // To accomplish this, we have a basic allocation policy, and also a
183 // failed allocation policy.
184 //
185 // The basic allocation policy controls how you allocate memory without
186 // attempting garbage collection. It is okay to grab locks and
187 // expand the heap, if that can be done without coming to a safepoint.
188 // It is likely that the basic allocation policy will not be very
189 // aggressive.
190 //
191 // The failed allocation policy is invoked from the VM thread after
192 // the basic allocation policy is unable to satisfy a mem_allocate
193 // request. This policy needs to cover the entire range of collection,
194 // heap expansion, and out-of-memory conditions. It should make every
195 // attempt to allocate the requested memory.
196
197 // Basic allocation policy. Should never be called at a safepoint, or
198 // from the VM thread.
199 //
200 // This method must handle cases where many mem_allocate requests fail
201 // simultaneously. When that happens, only one VM operation will succeed,
202 // and the rest will not be executed. For that reason, this method loops
203 // during failed allocation attempts. If the java heap becomes exhausted,
204 // we rely on the size_policy object to force a bail out.
205 HeapWord* ParallelScavengeHeap::mem_allocate(
206 size_t size,
207 bool* gc_overhead_limit_was_exceeded) {
208 assert(!SafepointSynchronize::is_at_safepoint(), "should not be at safepoint");
209 assert(Thread::current() != (Thread*)VMThread::vm_thread(), "should not be in vm thread");
210 assert(!Heap_lock->owned_by_self(), "this thread should not own the Heap_lock");
211
212 // In general gc_overhead_limit_was_exceeded should be false so
213 // set it so here and reset it to true only if the gc time
214 // limit is being exceeded as checked below.
215 *gc_overhead_limit_was_exceeded = false;
216
217 HeapWord* result = young_gen()->allocate(size);
218
219 uint loop_count = 0;
220 uint gc_count = 0;
221 uint gclocker_stalled_count = 0;
222
223 while (result == NULL) {
224 // We don't want to have multiple collections for a single filled generation.
225 // To prevent this, each thread tracks the total_collections() value, and if
226 // the count has changed, does not do a new collection.
227 //
228 // The collection count must be read only while holding the heap lock. VM
229 // operations also hold the heap lock during collections. There is a lock
230 // contention case where thread A blocks waiting on the Heap_lock, while
231 // thread B is holding it doing a collection. When thread A gets the lock,
232 // the collection count has already changed. To prevent duplicate collections,
233 // The policy MUST attempt allocations during the same period it reads the
234 // total_collections() value!
235 {
236 MutexLocker ml(Heap_lock);
237 gc_count = total_collections();
238
239 result = young_gen()->allocate(size);
240 if (result != NULL) {
241 return result;
242 }
243
244 // If certain conditions hold, try allocating from the old gen.
245 result = mem_allocate_old_gen(size);
246 if (result != NULL) {
247 return result;
248 }
249
250 if (gclocker_stalled_count > GCLockerRetryAllocationCount) {
251 return NULL;
252 }
253
254 // Failed to allocate without a gc.
255 if (GCLocker::is_active_and_needs_gc()) {
256 // If this thread is not in a jni critical section, we stall
257 // the requestor until the critical section has cleared and
258 // GC allowed. When the critical section clears, a GC is
259 // initiated by the last thread exiting the critical section; so
260 // we retry the allocation sequence from the beginning of the loop,
261 // rather than causing more, now probably unnecessary, GC attempts.
262 JavaThread* jthr = JavaThread::current();
263 if (!jthr->in_critical()) {
264 MutexUnlocker mul(Heap_lock);
265 GCLocker::stall_until_clear();
266 gclocker_stalled_count += 1;
267 continue;
268 } else {
269 if (CheckJNICalls) {
270 fatal("Possible deadlock due to allocating while"
271 " in jni critical section");
272 }
273 return NULL;
274 }
275 }
276 }
277
278 if (result == NULL) {
279 // Generate a VM operation
280 VM_ParallelGCFailedAllocation op(size, gc_count);
281 VMThread::execute(&op);
282
283 // Did the VM operation execute? If so, return the result directly.
284 // This prevents us from looping until time out on requests that can
285 // not be satisfied.
286 if (op.prologue_succeeded()) {
287 assert(is_in_or_null(op.result()), "result not in heap");
288
289 // If GC was locked out during VM operation then retry allocation
290 // and/or stall as necessary.
291 if (op.gc_locked()) {
292 assert(op.result() == NULL, "must be NULL if gc_locked() is true");
293 continue; // retry and/or stall as necessary
294 }
295
296 // Exit the loop if the gc time limit has been exceeded.
297 // The allocation must have failed above ("result" guarding
298 // this path is NULL) and the most recent collection has exceeded the
299 // gc overhead limit (although enough may have been collected to
300 // satisfy the allocation). Exit the loop so that an out-of-memory
301 // will be thrown (return a NULL ignoring the contents of
302 // op.result()),
303 // but clear gc_overhead_limit_exceeded so that the next collection
304 // starts with a clean slate (i.e., forgets about previous overhead
305 // excesses). Fill op.result() with a filler object so that the
306 // heap remains parsable.
307 const bool limit_exceeded = size_policy()->gc_overhead_limit_exceeded();
308 const bool softrefs_clear = collector_policy()->all_soft_refs_clear();
309
310 if (limit_exceeded && softrefs_clear) {
311 *gc_overhead_limit_was_exceeded = true;
312 size_policy()->set_gc_overhead_limit_exceeded(false);
313 log_trace(gc)("ParallelScavengeHeap::mem_allocate: return NULL because gc_overhead_limit_exceeded is set");
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 log_warning(gc)("ParallelScavengeHeap::mem_allocate retries %d times", loop_count);
330 log_warning(gc)("\tsize=" SIZE_FORMAT, 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) || GCLocker::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 AdaptiveSizePolicyOutput::print();
577 log_debug(gc, heap, exit)("Accumulated young generation GC time %3.7f secs", PSScavenge::accumulated_time()->seconds());
578 log_debug(gc, heap, exit)("Accumulated old generation GC time %3.7f secs",
579 UseParallelOldGC ? PSParallelCompact::accumulated_time()->seconds() : PSMarkSweep::accumulated_time()->seconds());
580 }
581
582
583 void ParallelScavengeHeap::verify(VerifyOption option /* ignored */) {
584 // Why do we need the total_collections()-filter below?
585 if (total_collections() > 0) {
586 log_debug(gc, verify)("Tenured");
587 old_gen()->verify();
588
589 log_debug(gc, verify)("Eden");
590 young_gen()->verify();
591 }
592 }
593
594 void ParallelScavengeHeap::trace_heap(GCWhen::Type when, const GCTracer* gc_tracer) {
595 const PSHeapSummary& heap_summary = create_ps_heap_summary();
596 gc_tracer->report_gc_heap_summary(when, heap_summary);
597
598 const MetaspaceSummary& metaspace_summary = create_metaspace_summary();
599 gc_tracer->report_metaspace_summary(when, metaspace_summary);
600 }
601
602 ParallelScavengeHeap* ParallelScavengeHeap::heap() {
603 CollectedHeap* heap = Universe::heap();
604 assert(heap != NULL, "Uninitialized access to ParallelScavengeHeap::heap()");
605 assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Not a ParallelScavengeHeap");
606 return (ParallelScavengeHeap*)heap;
607 }
608
609 // Before delegating the resize to the young generation,
610 // the reserved space for the young and old generations
611 // may be changed to accommodate the desired resize.
612 void ParallelScavengeHeap::resize_young_gen(size_t eden_size,
613 size_t survivor_size) {
614 if (UseAdaptiveGCBoundary) {
615 if (size_policy()->bytes_absorbed_from_eden() != 0) {
616 size_policy()->reset_bytes_absorbed_from_eden();
617 return; // The generation changed size already.
618 }
619 gens()->adjust_boundary_for_young_gen_needs(eden_size, survivor_size);
620 }
621
622 // Delegate the resize to the generation.
623 _young_gen->resize(eden_size, survivor_size);
624 }
625
626 // Before delegating the resize to the old generation,
627 // the reserved space for the young and old generations
628 // may be changed to accommodate the desired resize.
629 void ParallelScavengeHeap::resize_old_gen(size_t desired_free_space) {
630 if (UseAdaptiveGCBoundary) {
631 if (size_policy()->bytes_absorbed_from_eden() != 0) {
632 size_policy()->reset_bytes_absorbed_from_eden();
633 return; // The generation changed size already.
634 }
635 gens()->adjust_boundary_for_old_gen_needs(desired_free_space);
636 }
637
638 // Delegate the resize to the generation.
639 _old_gen->resize(desired_free_space);
640 }
641
642 ParallelScavengeHeap::ParStrongRootsScope::ParStrongRootsScope() {
643 // nothing particular
644 }
645
646 ParallelScavengeHeap::ParStrongRootsScope::~ParStrongRootsScope() {
647 // nothing particular
648 }
649
650 #ifndef PRODUCT
651 void ParallelScavengeHeap::record_gen_tops_before_GC() {
652 if (ZapUnusedHeapArea) {
653 young_gen()->record_spaces_top();
654 old_gen()->record_spaces_top();
655 }
656 }
657
658 void ParallelScavengeHeap::gen_mangle_unused_area() {
659 if (ZapUnusedHeapArea) {
660 young_gen()->eden_space()->mangle_unused_area();
661 young_gen()->to_space()->mangle_unused_area();
662 young_gen()->from_space()->mangle_unused_area();
663 old_gen()->object_space()->mangle_unused_area();
664 }
665 }
666 #endif
667
668 bool ParallelScavengeHeap::is_scavengable(oop obj) {
669 return is_in_young(obj);
670 }
671
672 void ParallelScavengeHeap::register_nmethod(nmethod* nm) {
673 CodeCache::register_scavenge_root_nmethod(nm);
674 }
675
676 void ParallelScavengeHeap::verify_nmethod(nmethod* nm) {
677 CodeCache::verify_scavenge_root_nmethod(nm);
678 }
679
680 class PSScavengeMemoryManager : public GCMemoryManager {
681 private:
682 public:
683 PSScavengeMemoryManager() : GCMemoryManager() {}
684
685 const char* name() { return "PS Scavenge"; }
686 };
687
688 class PSMarkSweepMemoryManager : public GCMemoryManager {
689 private:
690 public:
691 PSMarkSweepMemoryManager() : GCMemoryManager() {}
692
693 const char* name() { return "PS MarkSweep"; }
694 };
695
696 GrowableArray<GCMemoryManager*> ParallelScavengeHeap::memory_managers() {
697 _minor_mgr = new PSScavengeMemoryManager();
698 _major_mgr = new PSMarkSweepMemoryManager();
699 GrowableArray<GCMemoryManager*> mem_mgrs;
700 mem_mgrs.append(_minor_mgr);
701 mem_mgrs.append(_major_mgr);
702 return mem_mgrs;
703 }
704
705 GrowableArray<MemoryPool*> ParallelScavengeHeap::memory_pools() {
706 PSYoungGen* young = young_gen();
707 EdenMutableSpacePool* eden = new EdenMutableSpacePool(young,
708 young->eden_space(),
709 "PS Eden Space",
710 MemoryPool::Heap,
711 false /* support_usage_threshold */);
712
713 SurvivorMutableSpacePool* survivor = new SurvivorMutableSpacePool(young,
714 "PS Survivor Space",
715 MemoryPool::Heap,
716 false /* support_usage_threshold */);
717
718 PSGenerationPool* old_gen_pool = new PSGenerationPool(old_gen(),
719 "PS Old Gen",
720 MemoryPool::Heap,
721 true /* support_usage_threshold */);
722
723 _major_mgr->add_pool(eden);
724 _major_mgr->add_pool(survivor);
725 _major_mgr->add_pool(old_gen_pool);
726
727 _minor_mgr->add_pool(eden);
728 _minor_mgr->add_pool(survivor);
729
730 GrowableArray<MemoryPool*> mem_pools;
731 mem_pools.append(eden);
732 mem_pools.append(survivor);
733 mem_pools.append(old_gen_pool);
734 return mem_pools;
735 }
736