| /* |
| * Copyright (c) 2001, 2013, 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/generationSizer.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/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" |
| |
| 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(); |
| GCCause::Cause gc_cause = heap->gc_cause(); |
| assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity"); |
| 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(); |
| |
| // 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(); |
| |
| // 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); |
| TraceTime t1(GCCauseString("Full GC", gc_cause), PrintGC, !PrintGCDetails, gclog_or_tty); |
| 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::allocated_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->post_full_gc_dump(); |
| |
| #ifdef TRACESPINNING |
| ParallelTaskTerminator::print_termination_counts(); |
| #endif |
| |
| 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 |
| TraceTime tm("phase 1", PrintGCDetails && Verbose, true, gclog_or_tty); |
| 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); |
| ref_processor()->process_discovered_references( |
| is_alive_closure(), mark_and_push_closure(), follow_stack_closure(), NULL); |
| } |
| |
| // 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(); |
| } |
| |
| |
| void PSMarkSweep::mark_sweep_phase2() { |
| TraceTime tm("phase 2", PrintGCDetails && Verbose, true, gclog_or_tty); |
| 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 |
| TraceTime tm("phase 3", PrintGCDetails && Verbose, true, gclog_or_tty); |
| 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"); |
| TraceTime tm("phase 4", PrintGCDetails && Verbose, true, gclog_or_tty); |
| 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; |
| } |