diff -r 000000000000 -r f90c822e73f8 src/share/vm/gc_implementation/parallelScavenge/psMarkSweep.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/share/vm/gc_implementation/parallelScavenge/psMarkSweep.cpp Wed Apr 27 01:25:04 2016 +0800 @@ -0,0 +1,682 @@ +/* + * Copyright (c) 2001, 2014, Oracle and/or its affiliates. All rights reserved. + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. + * + * This code is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 only, as + * published by the Free Software Foundation. + * + * This code is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * version 2 for more details (a copy is included in the LICENSE file that + * accompanied this code). + * + * You should have received a copy of the GNU General Public License version + * 2 along with this work; if not, write to the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. + * + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA + * or visit www.oracle.com if you need additional information or have any + * questions. + * + */ + +#include "precompiled.hpp" +#include "classfile/symbolTable.hpp" +#include "classfile/systemDictionary.hpp" +#include "code/codeCache.hpp" +#include "gc_implementation/parallelScavenge/parallelScavengeHeap.hpp" +#include "gc_implementation/parallelScavenge/psAdaptiveSizePolicy.hpp" +#include "gc_implementation/parallelScavenge/psMarkSweep.hpp" +#include "gc_implementation/parallelScavenge/psMarkSweepDecorator.hpp" +#include "gc_implementation/parallelScavenge/psOldGen.hpp" +#include "gc_implementation/parallelScavenge/psScavenge.hpp" +#include "gc_implementation/parallelScavenge/psYoungGen.hpp" +#include "gc_implementation/shared/gcHeapSummary.hpp" +#include "gc_implementation/shared/gcTimer.hpp" +#include "gc_implementation/shared/gcTrace.hpp" +#include "gc_implementation/shared/gcTraceTime.hpp" +#include "gc_implementation/shared/isGCActiveMark.hpp" +#include "gc_implementation/shared/markSweep.hpp" +#include "gc_implementation/shared/spaceDecorator.hpp" +#include "gc_interface/gcCause.hpp" +#include "memory/gcLocker.inline.hpp" +#include "memory/referencePolicy.hpp" +#include "memory/referenceProcessor.hpp" +#include "oops/oop.inline.hpp" +#include "runtime/biasedLocking.hpp" +#include "runtime/fprofiler.hpp" +#include "runtime/safepoint.hpp" +#include "runtime/vmThread.hpp" +#include "services/management.hpp" +#include "services/memoryService.hpp" +#include "utilities/events.hpp" +#include "utilities/stack.inline.hpp" + +PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC + +elapsedTimer PSMarkSweep::_accumulated_time; +jlong PSMarkSweep::_time_of_last_gc = 0; +CollectorCounters* PSMarkSweep::_counters = NULL; + +void PSMarkSweep::initialize() { + MemRegion mr = Universe::heap()->reserved_region(); + _ref_processor = new ReferenceProcessor(mr); // a vanilla ref proc + _counters = new CollectorCounters("PSMarkSweep", 1); +} + +// This method contains all heap specific policy for invoking mark sweep. +// PSMarkSweep::invoke_no_policy() will only attempt to mark-sweep-compact +// the heap. It will do nothing further. If we need to bail out for policy +// reasons, scavenge before full gc, or any other specialized behavior, it +// needs to be added here. +// +// Note that this method should only be called from the vm_thread while +// at a safepoint! +// +// Note that the all_soft_refs_clear flag in the collector policy +// may be true because this method can be called without intervening +// activity. For example when the heap space is tight and full measure +// are being taken to free space. + +void PSMarkSweep::invoke(bool maximum_heap_compaction) { + assert(SafepointSynchronize::is_at_safepoint(), "should be at safepoint"); + assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread"); + assert(!Universe::heap()->is_gc_active(), "not reentrant"); + + ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap(); + GCCause::Cause gc_cause = heap->gc_cause(); + PSAdaptiveSizePolicy* policy = heap->size_policy(); + IsGCActiveMark mark; + + if (ScavengeBeforeFullGC) { + PSScavenge::invoke_no_policy(); + } + + const bool clear_all_soft_refs = + heap->collector_policy()->should_clear_all_soft_refs(); + + uint count = maximum_heap_compaction ? 1 : MarkSweepAlwaysCompactCount; + UIntFlagSetting flag_setting(MarkSweepAlwaysCompactCount, count); + PSMarkSweep::invoke_no_policy(clear_all_soft_refs || maximum_heap_compaction); +} + +// This method contains no policy. You should probably +// be calling invoke() instead. +bool PSMarkSweep::invoke_no_policy(bool clear_all_softrefs) { + assert(SafepointSynchronize::is_at_safepoint(), "must be at a safepoint"); + assert(ref_processor() != NULL, "Sanity"); + + if (GC_locker::check_active_before_gc()) { + return false; + } + + ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap(); + assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity"); + GCCause::Cause gc_cause = heap->gc_cause(); + + _gc_timer->register_gc_start(); + _gc_tracer->report_gc_start(gc_cause, _gc_timer->gc_start()); + + PSAdaptiveSizePolicy* size_policy = heap->size_policy(); + + // The scope of casr should end after code that can change + // CollectorPolicy::_should_clear_all_soft_refs. + ClearedAllSoftRefs casr(clear_all_softrefs, heap->collector_policy()); + + PSYoungGen* young_gen = heap->young_gen(); + PSOldGen* old_gen = heap->old_gen(); + + // Increment the invocation count + heap->increment_total_collections(true /* full */); + + // Save information needed to minimize mangling + heap->record_gen_tops_before_GC(); + + // We need to track unique mark sweep invocations as well. + _total_invocations++; + + AdaptiveSizePolicyOutput(size_policy, heap->total_collections()); + + heap->print_heap_before_gc(); + heap->trace_heap_before_gc(_gc_tracer); + + // Fill in TLABs + heap->accumulate_statistics_all_tlabs(); + heap->ensure_parsability(true); // retire TLABs + + if (VerifyBeforeGC && heap->total_collections() >= VerifyGCStartAt) { + HandleMark hm; // Discard invalid handles created during verification + Universe::verify(" VerifyBeforeGC:"); + } + + // Verify object start arrays + if (VerifyObjectStartArray && + VerifyBeforeGC) { + old_gen->verify_object_start_array(); + } + + heap->pre_full_gc_dump(_gc_timer); + + // Filled in below to track the state of the young gen after the collection. + bool eden_empty; + bool survivors_empty; + bool young_gen_empty; + + { + HandleMark hm; + + gclog_or_tty->date_stamp(PrintGC && PrintGCDateStamps); + TraceCPUTime tcpu(PrintGCDetails, true, gclog_or_tty); + GCTraceTime t1(GCCauseString("Full GC", gc_cause), PrintGC, !PrintGCDetails, NULL); + TraceCollectorStats tcs(counters()); + TraceMemoryManagerStats tms(true /* Full GC */,gc_cause); + + if (TraceGen1Time) accumulated_time()->start(); + + // Let the size policy know we're starting + size_policy->major_collection_begin(); + + CodeCache::gc_prologue(); + Threads::gc_prologue(); + BiasedLocking::preserve_marks(); + + // Capture heap size before collection for printing. + size_t prev_used = heap->used(); + + // Capture metadata size before collection for sizing. + size_t metadata_prev_used = MetaspaceAux::used_bytes(); + + // For PrintGCDetails + size_t old_gen_prev_used = old_gen->used_in_bytes(); + size_t young_gen_prev_used = young_gen->used_in_bytes(); + + allocate_stacks(); + + COMPILER2_PRESENT(DerivedPointerTable::clear()); + + ref_processor()->enable_discovery(true /*verify_disabled*/, true /*verify_no_refs*/); + ref_processor()->setup_policy(clear_all_softrefs); + + mark_sweep_phase1(clear_all_softrefs); + + mark_sweep_phase2(); + + // Don't add any more derived pointers during phase3 + COMPILER2_PRESENT(assert(DerivedPointerTable::is_active(), "Sanity")); + COMPILER2_PRESENT(DerivedPointerTable::set_active(false)); + + mark_sweep_phase3(); + + mark_sweep_phase4(); + + restore_marks(); + + deallocate_stacks(); + + if (ZapUnusedHeapArea) { + // Do a complete mangle (top to end) because the usage for + // scratch does not maintain a top pointer. + young_gen->to_space()->mangle_unused_area_complete(); + } + + eden_empty = young_gen->eden_space()->is_empty(); + if (!eden_empty) { + eden_empty = absorb_live_data_from_eden(size_policy, young_gen, old_gen); + } + + // Update heap occupancy information which is used as + // input to soft ref clearing policy at the next gc. + Universe::update_heap_info_at_gc(); + + survivors_empty = young_gen->from_space()->is_empty() && + young_gen->to_space()->is_empty(); + young_gen_empty = eden_empty && survivors_empty; + + BarrierSet* bs = heap->barrier_set(); + if (bs->is_a(BarrierSet::ModRef)) { + ModRefBarrierSet* modBS = (ModRefBarrierSet*)bs; + MemRegion old_mr = heap->old_gen()->reserved(); + if (young_gen_empty) { + modBS->clear(MemRegion(old_mr.start(), old_mr.end())); + } else { + modBS->invalidate(MemRegion(old_mr.start(), old_mr.end())); + } + } + + // Delete metaspaces for unloaded class loaders and clean up loader_data graph + ClassLoaderDataGraph::purge(); + MetaspaceAux::verify_metrics(); + + BiasedLocking::restore_marks(); + Threads::gc_epilogue(); + CodeCache::gc_epilogue(); + JvmtiExport::gc_epilogue(); + + COMPILER2_PRESENT(DerivedPointerTable::update_pointers()); + + ref_processor()->enqueue_discovered_references(NULL); + + // Update time of last GC + reset_millis_since_last_gc(); + + // Let the size policy know we're done + size_policy->major_collection_end(old_gen->used_in_bytes(), gc_cause); + + if (UseAdaptiveSizePolicy) { + + if (PrintAdaptiveSizePolicy) { + gclog_or_tty->print("AdaptiveSizeStart: "); + gclog_or_tty->stamp(); + gclog_or_tty->print_cr(" collection: %d ", + heap->total_collections()); + if (Verbose) { + gclog_or_tty->print("old_gen_capacity: %d young_gen_capacity: %d", + old_gen->capacity_in_bytes(), young_gen->capacity_in_bytes()); + } + } + + // Don't check if the size_policy is ready here. Let + // the size_policy check that internally. + if (UseAdaptiveGenerationSizePolicyAtMajorCollection && + ((gc_cause != GCCause::_java_lang_system_gc) || + UseAdaptiveSizePolicyWithSystemGC)) { + // Calculate optimal free space amounts + assert(young_gen->max_size() > + young_gen->from_space()->capacity_in_bytes() + + young_gen->to_space()->capacity_in_bytes(), + "Sizes of space in young gen are out-of-bounds"); + + size_t young_live = young_gen->used_in_bytes(); + size_t eden_live = young_gen->eden_space()->used_in_bytes(); + size_t old_live = old_gen->used_in_bytes(); + size_t cur_eden = young_gen->eden_space()->capacity_in_bytes(); + size_t max_old_gen_size = old_gen->max_gen_size(); + size_t max_eden_size = young_gen->max_size() - + young_gen->from_space()->capacity_in_bytes() - + young_gen->to_space()->capacity_in_bytes(); + + // Used for diagnostics + size_policy->clear_generation_free_space_flags(); + + size_policy->compute_generations_free_space(young_live, + eden_live, + old_live, + cur_eden, + max_old_gen_size, + max_eden_size, + true /* full gc*/); + + size_policy->check_gc_overhead_limit(young_live, + eden_live, + max_old_gen_size, + max_eden_size, + true /* full gc*/, + gc_cause, + heap->collector_policy()); + + size_policy->decay_supplemental_growth(true /* full gc*/); + + heap->resize_old_gen(size_policy->calculated_old_free_size_in_bytes()); + + // Don't resize the young generation at an major collection. A + // desired young generation size may have been calculated but + // resizing the young generation complicates the code because the + // resizing of the old generation may have moved the boundary + // between the young generation and the old generation. Let the + // young generation resizing happen at the minor collections. + } + if (PrintAdaptiveSizePolicy) { + gclog_or_tty->print_cr("AdaptiveSizeStop: collection: %d ", + heap->total_collections()); + } + } + + if (UsePerfData) { + heap->gc_policy_counters()->update_counters(); + heap->gc_policy_counters()->update_old_capacity( + old_gen->capacity_in_bytes()); + heap->gc_policy_counters()->update_young_capacity( + young_gen->capacity_in_bytes()); + } + + heap->resize_all_tlabs(); + + // We collected the heap, recalculate the metaspace capacity + MetaspaceGC::compute_new_size(); + + if (TraceGen1Time) accumulated_time()->stop(); + + if (PrintGC) { + if (PrintGCDetails) { + // Don't print a GC timestamp here. This is after the GC so + // would be confusing. + young_gen->print_used_change(young_gen_prev_used); + old_gen->print_used_change(old_gen_prev_used); + } + heap->print_heap_change(prev_used); + if (PrintGCDetails) { + MetaspaceAux::print_metaspace_change(metadata_prev_used); + } + } + + // Track memory usage and detect low memory + MemoryService::track_memory_usage(); + heap->update_counters(); + } + + if (VerifyAfterGC && heap->total_collections() >= VerifyGCStartAt) { + HandleMark hm; // Discard invalid handles created during verification + Universe::verify(" VerifyAfterGC:"); + } + + // Re-verify object start arrays + if (VerifyObjectStartArray && + VerifyAfterGC) { + old_gen->verify_object_start_array(); + } + + if (ZapUnusedHeapArea) { + old_gen->object_space()->check_mangled_unused_area_complete(); + } + + NOT_PRODUCT(ref_processor()->verify_no_references_recorded()); + + heap->print_heap_after_gc(); + heap->trace_heap_after_gc(_gc_tracer); + + heap->post_full_gc_dump(_gc_timer); + +#ifdef TRACESPINNING + ParallelTaskTerminator::print_termination_counts(); +#endif + + _gc_timer->register_gc_end(); + + _gc_tracer->report_gc_end(_gc_timer->gc_end(), _gc_timer->time_partitions()); + + return true; +} + +bool PSMarkSweep::absorb_live_data_from_eden(PSAdaptiveSizePolicy* size_policy, + PSYoungGen* young_gen, + PSOldGen* old_gen) { + MutableSpace* const eden_space = young_gen->eden_space(); + assert(!eden_space->is_empty(), "eden must be non-empty"); + assert(young_gen->virtual_space()->alignment() == + old_gen->virtual_space()->alignment(), "alignments do not match"); + + if (!(UseAdaptiveSizePolicy && UseAdaptiveGCBoundary)) { + return false; + } + + // Both generations must be completely committed. + if (young_gen->virtual_space()->uncommitted_size() != 0) { + return false; + } + if (old_gen->virtual_space()->uncommitted_size() != 0) { + return false; + } + + // Figure out how much to take from eden. Include the average amount promoted + // in the total; otherwise the next young gen GC will simply bail out to a + // full GC. + const size_t alignment = old_gen->virtual_space()->alignment(); + const size_t eden_used = eden_space->used_in_bytes(); + const size_t promoted = (size_t)size_policy->avg_promoted()->padded_average(); + const size_t absorb_size = align_size_up(eden_used + promoted, alignment); + const size_t eden_capacity = eden_space->capacity_in_bytes(); + + if (absorb_size >= eden_capacity) { + return false; // Must leave some space in eden. + } + + const size_t new_young_size = young_gen->capacity_in_bytes() - absorb_size; + if (new_young_size < young_gen->min_gen_size()) { + return false; // Respect young gen minimum size. + } + + if (TraceAdaptiveGCBoundary && Verbose) { + gclog_or_tty->print(" absorbing " SIZE_FORMAT "K: " + "eden " SIZE_FORMAT "K->" SIZE_FORMAT "K " + "from " SIZE_FORMAT "K, to " SIZE_FORMAT "K " + "young_gen " SIZE_FORMAT "K->" SIZE_FORMAT "K ", + absorb_size / K, + eden_capacity / K, (eden_capacity - absorb_size) / K, + young_gen->from_space()->used_in_bytes() / K, + young_gen->to_space()->used_in_bytes() / K, + young_gen->capacity_in_bytes() / K, new_young_size / K); + } + + // Fill the unused part of the old gen. + MutableSpace* const old_space = old_gen->object_space(); + HeapWord* const unused_start = old_space->top(); + size_t const unused_words = pointer_delta(old_space->end(), unused_start); + + if (unused_words > 0) { + if (unused_words < CollectedHeap::min_fill_size()) { + return false; // If the old gen cannot be filled, must give up. + } + CollectedHeap::fill_with_objects(unused_start, unused_words); + } + + // Take the live data from eden and set both top and end in the old gen to + // eden top. (Need to set end because reset_after_change() mangles the region + // from end to virtual_space->high() in debug builds). + HeapWord* const new_top = eden_space->top(); + old_gen->virtual_space()->expand_into(young_gen->virtual_space(), + absorb_size); + young_gen->reset_after_change(); + old_space->set_top(new_top); + old_space->set_end(new_top); + old_gen->reset_after_change(); + + // Update the object start array for the filler object and the data from eden. + ObjectStartArray* const start_array = old_gen->start_array(); + for (HeapWord* p = unused_start; p < new_top; p += oop(p)->size()) { + start_array->allocate_block(p); + } + + // Could update the promoted average here, but it is not typically updated at + // full GCs and the value to use is unclear. Something like + // + // cur_promoted_avg + absorb_size / number_of_scavenges_since_last_full_gc. + + size_policy->set_bytes_absorbed_from_eden(absorb_size); + return true; +} + +void PSMarkSweep::allocate_stacks() { + ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap(); + assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity"); + + PSYoungGen* young_gen = heap->young_gen(); + + MutableSpace* to_space = young_gen->to_space(); + _preserved_marks = (PreservedMark*)to_space->top(); + _preserved_count = 0; + + // We want to calculate the size in bytes first. + _preserved_count_max = pointer_delta(to_space->end(), to_space->top(), sizeof(jbyte)); + // Now divide by the size of a PreservedMark + _preserved_count_max /= sizeof(PreservedMark); +} + + +void PSMarkSweep::deallocate_stacks() { + _preserved_mark_stack.clear(true); + _preserved_oop_stack.clear(true); + _marking_stack.clear(); + _objarray_stack.clear(true); +} + +void PSMarkSweep::mark_sweep_phase1(bool clear_all_softrefs) { + // Recursively traverse all live objects and mark them + GCTraceTime tm("phase 1", PrintGCDetails && Verbose, true, _gc_timer); + trace(" 1"); + + ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap(); + assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity"); + + // Need to clear claim bits before the tracing starts. + ClassLoaderDataGraph::clear_claimed_marks(); + + // General strong roots. + { + ParallelScavengeHeap::ParStrongRootsScope psrs; + Universe::oops_do(mark_and_push_closure()); + JNIHandles::oops_do(mark_and_push_closure()); // Global (strong) JNI handles + CLDToOopClosure mark_and_push_from_cld(mark_and_push_closure()); + CodeBlobToOopClosure each_active_code_blob(mark_and_push_closure(), /*do_marking=*/ true); + Threads::oops_do(mark_and_push_closure(), &mark_and_push_from_cld, &each_active_code_blob); + ObjectSynchronizer::oops_do(mark_and_push_closure()); + FlatProfiler::oops_do(mark_and_push_closure()); + Management::oops_do(mark_and_push_closure()); + JvmtiExport::oops_do(mark_and_push_closure()); + SystemDictionary::always_strong_oops_do(mark_and_push_closure()); + ClassLoaderDataGraph::always_strong_oops_do(mark_and_push_closure(), follow_klass_closure(), true); + // Do not treat nmethods as strong roots for mark/sweep, since we can unload them. + //CodeCache::scavenge_root_nmethods_do(CodeBlobToOopClosure(mark_and_push_closure())); + } + + // Flush marking stack. + follow_stack(); + + // Process reference objects found during marking + { + ref_processor()->setup_policy(clear_all_softrefs); + const ReferenceProcessorStats& stats = + ref_processor()->process_discovered_references( + is_alive_closure(), mark_and_push_closure(), follow_stack_closure(), NULL, _gc_timer); + gc_tracer()->report_gc_reference_stats(stats); + } + + // This is the point where the entire marking should have completed. + assert(_marking_stack.is_empty(), "Marking should have completed"); + + // Unload classes and purge the SystemDictionary. + bool purged_class = SystemDictionary::do_unloading(is_alive_closure()); + + // Unload nmethods. + CodeCache::do_unloading(is_alive_closure(), purged_class); + + // Prune dead klasses from subklass/sibling/implementor lists. + Klass::clean_weak_klass_links(is_alive_closure()); + + // Delete entries for dead interned strings. + StringTable::unlink(is_alive_closure()); + + // Clean up unreferenced symbols in symbol table. + SymbolTable::unlink(); + _gc_tracer->report_object_count_after_gc(is_alive_closure()); +} + + +void PSMarkSweep::mark_sweep_phase2() { + GCTraceTime tm("phase 2", PrintGCDetails && Verbose, true, _gc_timer); + trace("2"); + + // Now all live objects are marked, compute the new object addresses. + + // It is not required that we traverse spaces in the same order in + // phase2, phase3 and phase4, but the ValidateMarkSweep live oops + // tracking expects us to do so. See comment under phase4. + + ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap(); + assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity"); + + PSOldGen* old_gen = heap->old_gen(); + + // Begin compacting into the old gen + PSMarkSweepDecorator::set_destination_decorator_tenured(); + + // This will also compact the young gen spaces. + old_gen->precompact(); +} + +// This should be moved to the shared markSweep code! +class PSAlwaysTrueClosure: public BoolObjectClosure { +public: + bool do_object_b(oop p) { return true; } +}; +static PSAlwaysTrueClosure always_true; + +void PSMarkSweep::mark_sweep_phase3() { + // Adjust the pointers to reflect the new locations + GCTraceTime tm("phase 3", PrintGCDetails && Verbose, true, _gc_timer); + trace("3"); + + ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap(); + assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity"); + + PSYoungGen* young_gen = heap->young_gen(); + PSOldGen* old_gen = heap->old_gen(); + + // Need to clear claim bits before the tracing starts. + ClassLoaderDataGraph::clear_claimed_marks(); + + // General strong roots. + Universe::oops_do(adjust_pointer_closure()); + JNIHandles::oops_do(adjust_pointer_closure()); // Global (strong) JNI handles + CLDToOopClosure adjust_from_cld(adjust_pointer_closure()); + Threads::oops_do(adjust_pointer_closure(), &adjust_from_cld, NULL); + ObjectSynchronizer::oops_do(adjust_pointer_closure()); + FlatProfiler::oops_do(adjust_pointer_closure()); + Management::oops_do(adjust_pointer_closure()); + JvmtiExport::oops_do(adjust_pointer_closure()); + // SO_AllClasses + SystemDictionary::oops_do(adjust_pointer_closure()); + ClassLoaderDataGraph::oops_do(adjust_pointer_closure(), adjust_klass_closure(), true); + + // Now adjust pointers in remaining weak roots. (All of which should + // have been cleared if they pointed to non-surviving objects.) + // Global (weak) JNI handles + JNIHandles::weak_oops_do(&always_true, adjust_pointer_closure()); + + CodeCache::oops_do(adjust_pointer_closure()); + StringTable::oops_do(adjust_pointer_closure()); + ref_processor()->weak_oops_do(adjust_pointer_closure()); + PSScavenge::reference_processor()->weak_oops_do(adjust_pointer_closure()); + + adjust_marks(); + + young_gen->adjust_pointers(); + old_gen->adjust_pointers(); +} + +void PSMarkSweep::mark_sweep_phase4() { + EventMark m("4 compact heap"); + GCTraceTime tm("phase 4", PrintGCDetails && Verbose, true, _gc_timer); + trace("4"); + + // All pointers are now adjusted, move objects accordingly + + ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap(); + assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity"); + + PSYoungGen* young_gen = heap->young_gen(); + PSOldGen* old_gen = heap->old_gen(); + + old_gen->compact(); + young_gen->compact(); +} + +jlong PSMarkSweep::millis_since_last_gc() { + // We need a monotonically non-deccreasing time in ms but + // os::javaTimeMillis() does not guarantee monotonicity. + jlong now = os::javaTimeNanos() / NANOSECS_PER_MILLISEC; + jlong ret_val = now - _time_of_last_gc; + // XXX See note in genCollectedHeap::millis_since_last_gc(). + if (ret_val < 0) { + NOT_PRODUCT(warning("time warp: "INT64_FORMAT, ret_val);) + return 0; + } + return ret_val; +} + +void PSMarkSweep::reset_millis_since_last_gc() { + // We need a monotonically non-deccreasing time in ms but + // os::javaTimeMillis() does not guarantee monotonicity. + _time_of_last_gc = os::javaTimeNanos() / NANOSECS_PER_MILLISEC; +}