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