Fri, 17 May 2013 11:57:05 +0200
8014277: Remove ObjectClosure as base class for BoolObjectClosure
Reviewed-by: brutisso, tschatzl
1 /*
2 * Copyright (c) 2001, 2013, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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13 * accompanied this code).
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23 */
25 #include "precompiled.hpp"
26 #include "classfile/symbolTable.hpp"
27 #include "classfile/systemDictionary.hpp"
28 #include "code/codeCache.hpp"
29 #include "gc_implementation/parallelScavenge/generationSizer.hpp"
30 #include "gc_implementation/parallelScavenge/parallelScavengeHeap.hpp"
31 #include "gc_implementation/parallelScavenge/psAdaptiveSizePolicy.hpp"
32 #include "gc_implementation/parallelScavenge/psMarkSweep.hpp"
33 #include "gc_implementation/parallelScavenge/psMarkSweepDecorator.hpp"
34 #include "gc_implementation/parallelScavenge/psOldGen.hpp"
35 #include "gc_implementation/parallelScavenge/psScavenge.hpp"
36 #include "gc_implementation/parallelScavenge/psYoungGen.hpp"
37 #include "gc_implementation/shared/isGCActiveMark.hpp"
38 #include "gc_implementation/shared/markSweep.hpp"
39 #include "gc_implementation/shared/spaceDecorator.hpp"
40 #include "gc_interface/gcCause.hpp"
41 #include "memory/gcLocker.inline.hpp"
42 #include "memory/referencePolicy.hpp"
43 #include "memory/referenceProcessor.hpp"
44 #include "oops/oop.inline.hpp"
45 #include "runtime/biasedLocking.hpp"
46 #include "runtime/fprofiler.hpp"
47 #include "runtime/safepoint.hpp"
48 #include "runtime/vmThread.hpp"
49 #include "services/management.hpp"
50 #include "services/memoryService.hpp"
51 #include "utilities/events.hpp"
52 #include "utilities/stack.inline.hpp"
54 elapsedTimer PSMarkSweep::_accumulated_time;
55 jlong PSMarkSweep::_time_of_last_gc = 0;
56 CollectorCounters* PSMarkSweep::_counters = NULL;
58 void PSMarkSweep::initialize() {
59 MemRegion mr = Universe::heap()->reserved_region();
60 _ref_processor = new ReferenceProcessor(mr); // a vanilla ref proc
61 _counters = new CollectorCounters("PSMarkSweep", 1);
62 }
64 // This method contains all heap specific policy for invoking mark sweep.
65 // PSMarkSweep::invoke_no_policy() will only attempt to mark-sweep-compact
66 // the heap. It will do nothing further. If we need to bail out for policy
67 // reasons, scavenge before full gc, or any other specialized behavior, it
68 // needs to be added here.
69 //
70 // Note that this method should only be called from the vm_thread while
71 // at a safepoint!
72 //
73 // Note that the all_soft_refs_clear flag in the collector policy
74 // may be true because this method can be called without intervening
75 // activity. For example when the heap space is tight and full measure
76 // are being taken to free space.
78 void PSMarkSweep::invoke(bool maximum_heap_compaction) {
79 assert(SafepointSynchronize::is_at_safepoint(), "should be at safepoint");
80 assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread");
81 assert(!Universe::heap()->is_gc_active(), "not reentrant");
83 ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
84 GCCause::Cause gc_cause = heap->gc_cause();
85 PSAdaptiveSizePolicy* policy = heap->size_policy();
86 IsGCActiveMark mark;
88 if (ScavengeBeforeFullGC) {
89 PSScavenge::invoke_no_policy();
90 }
92 const bool clear_all_soft_refs =
93 heap->collector_policy()->should_clear_all_soft_refs();
95 uint count = maximum_heap_compaction ? 1 : MarkSweepAlwaysCompactCount;
96 UIntFlagSetting flag_setting(MarkSweepAlwaysCompactCount, count);
97 PSMarkSweep::invoke_no_policy(clear_all_soft_refs || maximum_heap_compaction);
98 }
100 // This method contains no policy. You should probably
101 // be calling invoke() instead.
102 bool PSMarkSweep::invoke_no_policy(bool clear_all_softrefs) {
103 assert(SafepointSynchronize::is_at_safepoint(), "must be at a safepoint");
104 assert(ref_processor() != NULL, "Sanity");
106 if (GC_locker::check_active_before_gc()) {
107 return false;
108 }
110 ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
111 GCCause::Cause gc_cause = heap->gc_cause();
112 assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
113 PSAdaptiveSizePolicy* size_policy = heap->size_policy();
115 // The scope of casr should end after code that can change
116 // CollectorPolicy::_should_clear_all_soft_refs.
117 ClearedAllSoftRefs casr(clear_all_softrefs, heap->collector_policy());
119 PSYoungGen* young_gen = heap->young_gen();
120 PSOldGen* old_gen = heap->old_gen();
122 // Increment the invocation count
123 heap->increment_total_collections(true /* full */);
125 // Save information needed to minimize mangling
126 heap->record_gen_tops_before_GC();
128 // We need to track unique mark sweep invocations as well.
129 _total_invocations++;
131 AdaptiveSizePolicyOutput(size_policy, heap->total_collections());
133 heap->print_heap_before_gc();
135 // Fill in TLABs
136 heap->accumulate_statistics_all_tlabs();
137 heap->ensure_parsability(true); // retire TLABs
139 if (VerifyBeforeGC && heap->total_collections() >= VerifyGCStartAt) {
140 HandleMark hm; // Discard invalid handles created during verification
141 Universe::verify(" VerifyBeforeGC:");
142 }
144 // Verify object start arrays
145 if (VerifyObjectStartArray &&
146 VerifyBeforeGC) {
147 old_gen->verify_object_start_array();
148 }
150 heap->pre_full_gc_dump();
152 // Filled in below to track the state of the young gen after the collection.
153 bool eden_empty;
154 bool survivors_empty;
155 bool young_gen_empty;
157 {
158 HandleMark hm;
160 gclog_or_tty->date_stamp(PrintGC && PrintGCDateStamps);
161 TraceCPUTime tcpu(PrintGCDetails, true, gclog_or_tty);
162 TraceTime t1(GCCauseString("Full GC", gc_cause), PrintGC, !PrintGCDetails, gclog_or_tty);
163 TraceCollectorStats tcs(counters());
164 TraceMemoryManagerStats tms(true /* Full GC */,gc_cause);
166 if (TraceGen1Time) accumulated_time()->start();
168 // Let the size policy know we're starting
169 size_policy->major_collection_begin();
171 CodeCache::gc_prologue();
172 Threads::gc_prologue();
173 BiasedLocking::preserve_marks();
175 // Capture heap size before collection for printing.
176 size_t prev_used = heap->used();
178 // Capture metadata size before collection for sizing.
179 size_t metadata_prev_used = MetaspaceAux::allocated_used_bytes();
181 // For PrintGCDetails
182 size_t old_gen_prev_used = old_gen->used_in_bytes();
183 size_t young_gen_prev_used = young_gen->used_in_bytes();
185 allocate_stacks();
187 COMPILER2_PRESENT(DerivedPointerTable::clear());
189 ref_processor()->enable_discovery(true /*verify_disabled*/, true /*verify_no_refs*/);
190 ref_processor()->setup_policy(clear_all_softrefs);
192 mark_sweep_phase1(clear_all_softrefs);
194 mark_sweep_phase2();
196 // Don't add any more derived pointers during phase3
197 COMPILER2_PRESENT(assert(DerivedPointerTable::is_active(), "Sanity"));
198 COMPILER2_PRESENT(DerivedPointerTable::set_active(false));
200 mark_sweep_phase3();
202 mark_sweep_phase4();
204 restore_marks();
206 deallocate_stacks();
208 if (ZapUnusedHeapArea) {
209 // Do a complete mangle (top to end) because the usage for
210 // scratch does not maintain a top pointer.
211 young_gen->to_space()->mangle_unused_area_complete();
212 }
214 eden_empty = young_gen->eden_space()->is_empty();
215 if (!eden_empty) {
216 eden_empty = absorb_live_data_from_eden(size_policy, young_gen, old_gen);
217 }
219 // Update heap occupancy information which is used as
220 // input to soft ref clearing policy at the next gc.
221 Universe::update_heap_info_at_gc();
223 survivors_empty = young_gen->from_space()->is_empty() &&
224 young_gen->to_space()->is_empty();
225 young_gen_empty = eden_empty && survivors_empty;
227 BarrierSet* bs = heap->barrier_set();
228 if (bs->is_a(BarrierSet::ModRef)) {
229 ModRefBarrierSet* modBS = (ModRefBarrierSet*)bs;
230 MemRegion old_mr = heap->old_gen()->reserved();
231 if (young_gen_empty) {
232 modBS->clear(MemRegion(old_mr.start(), old_mr.end()));
233 } else {
234 modBS->invalidate(MemRegion(old_mr.start(), old_mr.end()));
235 }
236 }
238 // Delete metaspaces for unloaded class loaders and clean up loader_data graph
239 ClassLoaderDataGraph::purge();
240 MetaspaceAux::verify_metrics();
242 BiasedLocking::restore_marks();
243 Threads::gc_epilogue();
244 CodeCache::gc_epilogue();
245 JvmtiExport::gc_epilogue();
247 COMPILER2_PRESENT(DerivedPointerTable::update_pointers());
249 ref_processor()->enqueue_discovered_references(NULL);
251 // Update time of last GC
252 reset_millis_since_last_gc();
254 // Let the size policy know we're done
255 size_policy->major_collection_end(old_gen->used_in_bytes(), gc_cause);
257 if (UseAdaptiveSizePolicy) {
259 if (PrintAdaptiveSizePolicy) {
260 gclog_or_tty->print("AdaptiveSizeStart: ");
261 gclog_or_tty->stamp();
262 gclog_or_tty->print_cr(" collection: %d ",
263 heap->total_collections());
264 if (Verbose) {
265 gclog_or_tty->print("old_gen_capacity: %d young_gen_capacity: %d",
266 old_gen->capacity_in_bytes(), young_gen->capacity_in_bytes());
267 }
268 }
270 // Don't check if the size_policy is ready here. Let
271 // the size_policy check that internally.
272 if (UseAdaptiveGenerationSizePolicyAtMajorCollection &&
273 ((gc_cause != GCCause::_java_lang_system_gc) ||
274 UseAdaptiveSizePolicyWithSystemGC)) {
275 // Calculate optimal free space amounts
276 assert(young_gen->max_size() >
277 young_gen->from_space()->capacity_in_bytes() +
278 young_gen->to_space()->capacity_in_bytes(),
279 "Sizes of space in young gen are out-of-bounds");
281 size_t young_live = young_gen->used_in_bytes();
282 size_t eden_live = young_gen->eden_space()->used_in_bytes();
283 size_t old_live = old_gen->used_in_bytes();
284 size_t cur_eden = young_gen->eden_space()->capacity_in_bytes();
285 size_t max_old_gen_size = old_gen->max_gen_size();
286 size_t max_eden_size = young_gen->max_size() -
287 young_gen->from_space()->capacity_in_bytes() -
288 young_gen->to_space()->capacity_in_bytes();
290 // Used for diagnostics
291 size_policy->clear_generation_free_space_flags();
293 size_policy->compute_generation_free_space(young_live,
294 eden_live,
295 old_live,
296 cur_eden,
297 max_old_gen_size,
298 max_eden_size,
299 true /* full gc*/);
301 size_policy->check_gc_overhead_limit(young_live,
302 eden_live,
303 max_old_gen_size,
304 max_eden_size,
305 true /* full gc*/,
306 gc_cause,
307 heap->collector_policy());
309 size_policy->decay_supplemental_growth(true /* full gc*/);
311 heap->resize_old_gen(size_policy->calculated_old_free_size_in_bytes());
313 // Don't resize the young generation at an major collection. A
314 // desired young generation size may have been calculated but
315 // resizing the young generation complicates the code because the
316 // resizing of the old generation may have moved the boundary
317 // between the young generation and the old generation. Let the
318 // young generation resizing happen at the minor collections.
319 }
320 if (PrintAdaptiveSizePolicy) {
321 gclog_or_tty->print_cr("AdaptiveSizeStop: collection: %d ",
322 heap->total_collections());
323 }
324 }
326 if (UsePerfData) {
327 heap->gc_policy_counters()->update_counters();
328 heap->gc_policy_counters()->update_old_capacity(
329 old_gen->capacity_in_bytes());
330 heap->gc_policy_counters()->update_young_capacity(
331 young_gen->capacity_in_bytes());
332 }
334 heap->resize_all_tlabs();
336 // We collected the heap, recalculate the metaspace capacity
337 MetaspaceGC::compute_new_size();
339 if (TraceGen1Time) accumulated_time()->stop();
341 if (PrintGC) {
342 if (PrintGCDetails) {
343 // Don't print a GC timestamp here. This is after the GC so
344 // would be confusing.
345 young_gen->print_used_change(young_gen_prev_used);
346 old_gen->print_used_change(old_gen_prev_used);
347 }
348 heap->print_heap_change(prev_used);
349 if (PrintGCDetails) {
350 MetaspaceAux::print_metaspace_change(metadata_prev_used);
351 }
352 }
354 // Track memory usage and detect low memory
355 MemoryService::track_memory_usage();
356 heap->update_counters();
357 }
359 if (VerifyAfterGC && heap->total_collections() >= VerifyGCStartAt) {
360 HandleMark hm; // Discard invalid handles created during verification
361 Universe::verify(" VerifyAfterGC:");
362 }
364 // Re-verify object start arrays
365 if (VerifyObjectStartArray &&
366 VerifyAfterGC) {
367 old_gen->verify_object_start_array();
368 }
370 if (ZapUnusedHeapArea) {
371 old_gen->object_space()->check_mangled_unused_area_complete();
372 }
374 NOT_PRODUCT(ref_processor()->verify_no_references_recorded());
376 heap->print_heap_after_gc();
378 heap->post_full_gc_dump();
380 #ifdef TRACESPINNING
381 ParallelTaskTerminator::print_termination_counts();
382 #endif
384 return true;
385 }
387 bool PSMarkSweep::absorb_live_data_from_eden(PSAdaptiveSizePolicy* size_policy,
388 PSYoungGen* young_gen,
389 PSOldGen* old_gen) {
390 MutableSpace* const eden_space = young_gen->eden_space();
391 assert(!eden_space->is_empty(), "eden must be non-empty");
392 assert(young_gen->virtual_space()->alignment() ==
393 old_gen->virtual_space()->alignment(), "alignments do not match");
395 if (!(UseAdaptiveSizePolicy && UseAdaptiveGCBoundary)) {
396 return false;
397 }
399 // Both generations must be completely committed.
400 if (young_gen->virtual_space()->uncommitted_size() != 0) {
401 return false;
402 }
403 if (old_gen->virtual_space()->uncommitted_size() != 0) {
404 return false;
405 }
407 // Figure out how much to take from eden. Include the average amount promoted
408 // in the total; otherwise the next young gen GC will simply bail out to a
409 // full GC.
410 const size_t alignment = old_gen->virtual_space()->alignment();
411 const size_t eden_used = eden_space->used_in_bytes();
412 const size_t promoted = (size_t)size_policy->avg_promoted()->padded_average();
413 const size_t absorb_size = align_size_up(eden_used + promoted, alignment);
414 const size_t eden_capacity = eden_space->capacity_in_bytes();
416 if (absorb_size >= eden_capacity) {
417 return false; // Must leave some space in eden.
418 }
420 const size_t new_young_size = young_gen->capacity_in_bytes() - absorb_size;
421 if (new_young_size < young_gen->min_gen_size()) {
422 return false; // Respect young gen minimum size.
423 }
425 if (TraceAdaptiveGCBoundary && Verbose) {
426 gclog_or_tty->print(" absorbing " SIZE_FORMAT "K: "
427 "eden " SIZE_FORMAT "K->" SIZE_FORMAT "K "
428 "from " SIZE_FORMAT "K, to " SIZE_FORMAT "K "
429 "young_gen " SIZE_FORMAT "K->" SIZE_FORMAT "K ",
430 absorb_size / K,
431 eden_capacity / K, (eden_capacity - absorb_size) / K,
432 young_gen->from_space()->used_in_bytes() / K,
433 young_gen->to_space()->used_in_bytes() / K,
434 young_gen->capacity_in_bytes() / K, new_young_size / K);
435 }
437 // Fill the unused part of the old gen.
438 MutableSpace* const old_space = old_gen->object_space();
439 HeapWord* const unused_start = old_space->top();
440 size_t const unused_words = pointer_delta(old_space->end(), unused_start);
442 if (unused_words > 0) {
443 if (unused_words < CollectedHeap::min_fill_size()) {
444 return false; // If the old gen cannot be filled, must give up.
445 }
446 CollectedHeap::fill_with_objects(unused_start, unused_words);
447 }
449 // Take the live data from eden and set both top and end in the old gen to
450 // eden top. (Need to set end because reset_after_change() mangles the region
451 // from end to virtual_space->high() in debug builds).
452 HeapWord* const new_top = eden_space->top();
453 old_gen->virtual_space()->expand_into(young_gen->virtual_space(),
454 absorb_size);
455 young_gen->reset_after_change();
456 old_space->set_top(new_top);
457 old_space->set_end(new_top);
458 old_gen->reset_after_change();
460 // Update the object start array for the filler object and the data from eden.
461 ObjectStartArray* const start_array = old_gen->start_array();
462 for (HeapWord* p = unused_start; p < new_top; p += oop(p)->size()) {
463 start_array->allocate_block(p);
464 }
466 // Could update the promoted average here, but it is not typically updated at
467 // full GCs and the value to use is unclear. Something like
468 //
469 // cur_promoted_avg + absorb_size / number_of_scavenges_since_last_full_gc.
471 size_policy->set_bytes_absorbed_from_eden(absorb_size);
472 return true;
473 }
475 void PSMarkSweep::allocate_stacks() {
476 ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
477 assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
479 PSYoungGen* young_gen = heap->young_gen();
481 MutableSpace* to_space = young_gen->to_space();
482 _preserved_marks = (PreservedMark*)to_space->top();
483 _preserved_count = 0;
485 // We want to calculate the size in bytes first.
486 _preserved_count_max = pointer_delta(to_space->end(), to_space->top(), sizeof(jbyte));
487 // Now divide by the size of a PreservedMark
488 _preserved_count_max /= sizeof(PreservedMark);
489 }
492 void PSMarkSweep::deallocate_stacks() {
493 _preserved_mark_stack.clear(true);
494 _preserved_oop_stack.clear(true);
495 _marking_stack.clear();
496 _objarray_stack.clear(true);
497 }
499 void PSMarkSweep::mark_sweep_phase1(bool clear_all_softrefs) {
500 // Recursively traverse all live objects and mark them
501 TraceTime tm("phase 1", PrintGCDetails && Verbose, true, gclog_or_tty);
502 trace(" 1");
504 ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
505 assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
507 // Need to clear claim bits before the tracing starts.
508 ClassLoaderDataGraph::clear_claimed_marks();
510 // General strong roots.
511 {
512 ParallelScavengeHeap::ParStrongRootsScope psrs;
513 Universe::oops_do(mark_and_push_closure());
514 JNIHandles::oops_do(mark_and_push_closure()); // Global (strong) JNI handles
515 CLDToOopClosure mark_and_push_from_cld(mark_and_push_closure());
516 CodeBlobToOopClosure each_active_code_blob(mark_and_push_closure(), /*do_marking=*/ true);
517 Threads::oops_do(mark_and_push_closure(), &mark_and_push_from_cld, &each_active_code_blob);
518 ObjectSynchronizer::oops_do(mark_and_push_closure());
519 FlatProfiler::oops_do(mark_and_push_closure());
520 Management::oops_do(mark_and_push_closure());
521 JvmtiExport::oops_do(mark_and_push_closure());
522 SystemDictionary::always_strong_oops_do(mark_and_push_closure());
523 ClassLoaderDataGraph::always_strong_oops_do(mark_and_push_closure(), follow_klass_closure(), true);
524 // Do not treat nmethods as strong roots for mark/sweep, since we can unload them.
525 //CodeCache::scavenge_root_nmethods_do(CodeBlobToOopClosure(mark_and_push_closure()));
526 }
528 // Flush marking stack.
529 follow_stack();
531 // Process reference objects found during marking
532 {
533 ref_processor()->setup_policy(clear_all_softrefs);
534 ref_processor()->process_discovered_references(
535 is_alive_closure(), mark_and_push_closure(), follow_stack_closure(), NULL);
536 }
538 // This is the point where the entire marking should have completed.
539 assert(_marking_stack.is_empty(), "Marking should have completed");
541 // Unload classes and purge the SystemDictionary.
542 bool purged_class = SystemDictionary::do_unloading(is_alive_closure());
544 // Unload nmethods.
545 CodeCache::do_unloading(is_alive_closure(), purged_class);
547 // Prune dead klasses from subklass/sibling/implementor lists.
548 Klass::clean_weak_klass_links(is_alive_closure());
550 // Delete entries for dead interned strings.
551 StringTable::unlink(is_alive_closure());
553 // Clean up unreferenced symbols in symbol table.
554 SymbolTable::unlink();
555 }
558 void PSMarkSweep::mark_sweep_phase2() {
559 TraceTime tm("phase 2", PrintGCDetails && Verbose, true, gclog_or_tty);
560 trace("2");
562 // Now all live objects are marked, compute the new object addresses.
564 // It is not required that we traverse spaces in the same order in
565 // phase2, phase3 and phase4, but the ValidateMarkSweep live oops
566 // tracking expects us to do so. See comment under phase4.
568 ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
569 assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
571 PSOldGen* old_gen = heap->old_gen();
573 // Begin compacting into the old gen
574 PSMarkSweepDecorator::set_destination_decorator_tenured();
576 // This will also compact the young gen spaces.
577 old_gen->precompact();
578 }
580 // This should be moved to the shared markSweep code!
581 class PSAlwaysTrueClosure: public BoolObjectClosure {
582 public:
583 bool do_object_b(oop p) { return true; }
584 };
585 static PSAlwaysTrueClosure always_true;
587 void PSMarkSweep::mark_sweep_phase3() {
588 // Adjust the pointers to reflect the new locations
589 TraceTime tm("phase 3", PrintGCDetails && Verbose, true, gclog_or_tty);
590 trace("3");
592 ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
593 assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
595 PSYoungGen* young_gen = heap->young_gen();
596 PSOldGen* old_gen = heap->old_gen();
598 // Need to clear claim bits before the tracing starts.
599 ClassLoaderDataGraph::clear_claimed_marks();
601 // General strong roots.
602 Universe::oops_do(adjust_pointer_closure());
603 JNIHandles::oops_do(adjust_pointer_closure()); // Global (strong) JNI handles
604 CLDToOopClosure adjust_from_cld(adjust_pointer_closure());
605 Threads::oops_do(adjust_pointer_closure(), &adjust_from_cld, NULL);
606 ObjectSynchronizer::oops_do(adjust_pointer_closure());
607 FlatProfiler::oops_do(adjust_pointer_closure());
608 Management::oops_do(adjust_pointer_closure());
609 JvmtiExport::oops_do(adjust_pointer_closure());
610 // SO_AllClasses
611 SystemDictionary::oops_do(adjust_pointer_closure());
612 ClassLoaderDataGraph::oops_do(adjust_pointer_closure(), adjust_klass_closure(), true);
614 // Now adjust pointers in remaining weak roots. (All of which should
615 // have been cleared if they pointed to non-surviving objects.)
616 // Global (weak) JNI handles
617 JNIHandles::weak_oops_do(&always_true, adjust_pointer_closure());
619 CodeCache::oops_do(adjust_pointer_closure());
620 StringTable::oops_do(adjust_pointer_closure());
621 ref_processor()->weak_oops_do(adjust_pointer_closure());
622 PSScavenge::reference_processor()->weak_oops_do(adjust_pointer_closure());
624 adjust_marks();
626 young_gen->adjust_pointers();
627 old_gen->adjust_pointers();
628 }
630 void PSMarkSweep::mark_sweep_phase4() {
631 EventMark m("4 compact heap");
632 TraceTime tm("phase 4", PrintGCDetails && Verbose, true, gclog_or_tty);
633 trace("4");
635 // All pointers are now adjusted, move objects accordingly
637 ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
638 assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
640 PSYoungGen* young_gen = heap->young_gen();
641 PSOldGen* old_gen = heap->old_gen();
643 old_gen->compact();
644 young_gen->compact();
645 }
647 jlong PSMarkSweep::millis_since_last_gc() {
648 // We need a monotonically non-deccreasing time in ms but
649 // os::javaTimeMillis() does not guarantee monotonicity.
650 jlong now = os::javaTimeNanos() / NANOSECS_PER_MILLISEC;
651 jlong ret_val = now - _time_of_last_gc;
652 // XXX See note in genCollectedHeap::millis_since_last_gc().
653 if (ret_val < 0) {
654 NOT_PRODUCT(warning("time warp: "INT64_FORMAT, ret_val);)
655 return 0;
656 }
657 return ret_val;
658 }
660 void PSMarkSweep::reset_millis_since_last_gc() {
661 // We need a monotonically non-deccreasing time in ms but
662 // os::javaTimeMillis() does not guarantee monotonicity.
663 _time_of_last_gc = os::javaTimeNanos() / NANOSECS_PER_MILLISEC;
664 }