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/*
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* Copyright 2001-2007 Sun Microsystems, Inc. All Rights Reserved.
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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*
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* This code is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 only, as
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* published by the Free Software Foundation.
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*
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* This code is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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* version 2 for more details (a copy is included in the LICENSE file that
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* accompanied this code).
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*
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* You should have received a copy of the GNU General Public License version
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* 2 along with this work; if not, write to the Free Software Foundation,
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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*
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* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
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* CA 95054 USA or visit www.sun.com if you need additional information or
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* have any questions.
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*
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*/
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#include "incls/_precompiled.incl"
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#include "incls/_psMarkSweep.cpp.incl"
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elapsedTimer PSMarkSweep::_accumulated_time;
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unsigned int PSMarkSweep::_total_invocations = 0;
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jlong PSMarkSweep::_time_of_last_gc = 0;
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CollectorCounters* PSMarkSweep::_counters = NULL;
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void PSMarkSweep::initialize() {
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MemRegion mr = Universe::heap()->reserved_region();
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_ref_processor = new ReferenceProcessor(mr,
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true, // atomic_discovery
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false); // mt_discovery
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if (!UseParallelOldGC || !VerifyParallelOldWithMarkSweep) {
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_counters = new CollectorCounters("PSMarkSweep", 1);
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}
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}
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// This method contains all heap specific policy for invoking mark sweep.
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// PSMarkSweep::invoke_no_policy() will only attempt to mark-sweep-compact
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// the heap. It will do nothing further. If we need to bail out for policy
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// reasons, scavenge before full gc, or any other specialized behavior, it
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// needs to be added here.
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//
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// Note that this method should only be called from the vm_thread while
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// at a safepoint!
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void PSMarkSweep::invoke(bool maximum_heap_compaction) {
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assert(SafepointSynchronize::is_at_safepoint(), "should be at safepoint");
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assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread");
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assert(!Universe::heap()->is_gc_active(), "not reentrant");
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ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
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GCCause::Cause gc_cause = heap->gc_cause();
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PSAdaptiveSizePolicy* policy = heap->size_policy();
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// Before each allocation/collection attempt, find out from the
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// policy object if GCs are, on the whole, taking too long. If so,
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// bail out without attempting a collection. The exceptions are
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// for explicitly requested GC's.
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if (!policy->gc_time_limit_exceeded() ||
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GCCause::is_user_requested_gc(gc_cause) ||
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GCCause::is_serviceability_requested_gc(gc_cause)) {
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IsGCActiveMark mark;
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if (ScavengeBeforeFullGC) {
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PSScavenge::invoke_no_policy();
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}
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int count = (maximum_heap_compaction)?1:MarkSweepAlwaysCompactCount;
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IntFlagSetting flag_setting(MarkSweepAlwaysCompactCount, count);
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PSMarkSweep::invoke_no_policy(maximum_heap_compaction);
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}
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}
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// This method contains no policy. You should probably
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// be calling invoke() instead.
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void PSMarkSweep::invoke_no_policy(bool clear_all_softrefs) {
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assert(SafepointSynchronize::is_at_safepoint(), "must be at a safepoint");
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assert(ref_processor() != NULL, "Sanity");
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if (GC_locker::check_active_before_gc()) {
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return;
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}
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ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
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GCCause::Cause gc_cause = heap->gc_cause();
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assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
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PSAdaptiveSizePolicy* size_policy = heap->size_policy();
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PSYoungGen* young_gen = heap->young_gen();
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PSOldGen* old_gen = heap->old_gen();
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PSPermGen* perm_gen = heap->perm_gen();
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// Increment the invocation count
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heap->increment_total_collections(true /* full */);
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// We need to track unique mark sweep invocations as well.
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_total_invocations++;
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AdaptiveSizePolicyOutput(size_policy, heap->total_collections());
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if (PrintHeapAtGC) {
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Universe::print_heap_before_gc();
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}
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// Fill in TLABs
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heap->accumulate_statistics_all_tlabs();
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heap->ensure_parsability(true); // retire TLABs
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if (VerifyBeforeGC && heap->total_collections() >= VerifyGCStartAt) {
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HandleMark hm; // Discard invalid handles created during verification
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gclog_or_tty->print(" VerifyBeforeGC:");
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Universe::verify(true);
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}
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// Verify object start arrays
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if (VerifyObjectStartArray &&
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VerifyBeforeGC) {
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old_gen->verify_object_start_array();
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perm_gen->verify_object_start_array();
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}
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// Filled in below to track the state of the young gen after the collection.
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bool eden_empty;
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bool survivors_empty;
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bool young_gen_empty;
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{
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HandleMark hm;
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const bool is_system_gc = gc_cause == GCCause::_java_lang_system_gc;
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// This is useful for debugging but don't change the output the
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// the customer sees.
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const char* gc_cause_str = "Full GC";
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if (is_system_gc && PrintGCDetails) {
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gc_cause_str = "Full GC (System)";
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}
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gclog_or_tty->date_stamp(PrintGC && PrintGCDateStamps);
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TraceCPUTime tcpu(PrintGCDetails, true, gclog_or_tty);
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TraceTime t1(gc_cause_str, PrintGC, !PrintGCDetails, gclog_or_tty);
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TraceCollectorStats tcs(counters());
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TraceMemoryManagerStats tms(true /* Full GC */);
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if (TraceGen1Time) accumulated_time()->start();
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// Let the size policy know we're starting
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size_policy->major_collection_begin();
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// When collecting the permanent generation methodOops may be moving,
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// so we either have to flush all bcp data or convert it into bci.
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CodeCache::gc_prologue();
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Threads::gc_prologue();
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BiasedLocking::preserve_marks();
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// Capture heap size before collection for printing.
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size_t prev_used = heap->used();
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// Capture perm gen size before collection for sizing.
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size_t perm_gen_prev_used = perm_gen->used_in_bytes();
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// For PrintGCDetails
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size_t old_gen_prev_used = old_gen->used_in_bytes();
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size_t young_gen_prev_used = young_gen->used_in_bytes();
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allocate_stacks();
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NOT_PRODUCT(ref_processor()->verify_no_references_recorded());
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COMPILER2_PRESENT(DerivedPointerTable::clear());
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ref_processor()->enable_discovery();
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mark_sweep_phase1(clear_all_softrefs);
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mark_sweep_phase2();
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// Don't add any more derived pointers during phase3
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COMPILER2_PRESENT(assert(DerivedPointerTable::is_active(), "Sanity"));
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COMPILER2_PRESENT(DerivedPointerTable::set_active(false));
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mark_sweep_phase3();
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mark_sweep_phase4();
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restore_marks();
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deallocate_stacks();
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eden_empty = young_gen->eden_space()->is_empty();
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if (!eden_empty) {
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eden_empty = absorb_live_data_from_eden(size_policy, young_gen, old_gen);
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}
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// Update heap occupancy information which is used as
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// input to soft ref clearing policy at the next gc.
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Universe::update_heap_info_at_gc();
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survivors_empty = young_gen->from_space()->is_empty() &&
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young_gen->to_space()->is_empty();
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young_gen_empty = eden_empty && survivors_empty;
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BarrierSet* bs = heap->barrier_set();
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if (bs->is_a(BarrierSet::ModRef)) {
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ModRefBarrierSet* modBS = (ModRefBarrierSet*)bs;
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MemRegion old_mr = heap->old_gen()->reserved();
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MemRegion perm_mr = heap->perm_gen()->reserved();
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assert(perm_mr.end() <= old_mr.start(), "Generations out of order");
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if (young_gen_empty) {
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modBS->clear(MemRegion(perm_mr.start(), old_mr.end()));
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} else {
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modBS->invalidate(MemRegion(perm_mr.start(), old_mr.end()));
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}
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}
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BiasedLocking::restore_marks();
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Threads::gc_epilogue();
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CodeCache::gc_epilogue();
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COMPILER2_PRESENT(DerivedPointerTable::update_pointers());
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ref_processor()->enqueue_discovered_references(NULL);
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// Update time of last GC
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reset_millis_since_last_gc();
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// Let the size policy know we're done
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size_policy->major_collection_end(old_gen->used_in_bytes(), gc_cause);
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if (UseAdaptiveSizePolicy) {
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if (PrintAdaptiveSizePolicy) {
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gclog_or_tty->print("AdaptiveSizeStart: ");
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gclog_or_tty->stamp();
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gclog_or_tty->print_cr(" collection: %d ",
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heap->total_collections());
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if (Verbose) {
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gclog_or_tty->print("old_gen_capacity: %d young_gen_capacity: %d"
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" perm_gen_capacity: %d ",
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old_gen->capacity_in_bytes(), young_gen->capacity_in_bytes(),
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perm_gen->capacity_in_bytes());
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}
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}
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// Don't check if the size_policy is ready here. Let
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// the size_policy check that internally.
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if (UseAdaptiveGenerationSizePolicyAtMajorCollection &&
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((gc_cause != GCCause::_java_lang_system_gc) ||
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UseAdaptiveSizePolicyWithSystemGC)) {
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// Calculate optimal free space amounts
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assert(young_gen->max_size() >
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young_gen->from_space()->capacity_in_bytes() +
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young_gen->to_space()->capacity_in_bytes(),
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"Sizes of space in young gen are out-of-bounds");
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size_t max_eden_size = young_gen->max_size() -
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young_gen->from_space()->capacity_in_bytes() -
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young_gen->to_space()->capacity_in_bytes();
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size_policy->compute_generation_free_space(young_gen->used_in_bytes(),
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young_gen->eden_space()->used_in_bytes(),
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old_gen->used_in_bytes(),
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perm_gen->used_in_bytes(),
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young_gen->eden_space()->capacity_in_bytes(),
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old_gen->max_gen_size(),
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max_eden_size,
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true /* full gc*/,
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gc_cause);
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heap->resize_old_gen(size_policy->calculated_old_free_size_in_bytes());
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// Don't resize the young generation at an major collection. A
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// desired young generation size may have been calculated but
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// resizing the young generation complicates the code because the
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// resizing of the old generation may have moved the boundary
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// between the young generation and the old generation. Let the
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// young generation resizing happen at the minor collections.
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}
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if (PrintAdaptiveSizePolicy) {
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gclog_or_tty->print_cr("AdaptiveSizeStop: collection: %d ",
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heap->total_collections());
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}
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}
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if (UsePerfData) {
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heap->gc_policy_counters()->update_counters();
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heap->gc_policy_counters()->update_old_capacity(
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old_gen->capacity_in_bytes());
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heap->gc_policy_counters()->update_young_capacity(
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young_gen->capacity_in_bytes());
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}
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heap->resize_all_tlabs();
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// We collected the perm gen, so we'll resize it here.
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perm_gen->compute_new_size(perm_gen_prev_used);
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if (TraceGen1Time) accumulated_time()->stop();
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if (PrintGC) {
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if (PrintGCDetails) {
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// Don't print a GC timestamp here. This is after the GC so
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// would be confusing.
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young_gen->print_used_change(young_gen_prev_used);
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old_gen->print_used_change(old_gen_prev_used);
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}
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heap->print_heap_change(prev_used);
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// Do perm gen after heap becase prev_used does
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// not include the perm gen (done this way in the other
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// collectors).
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if (PrintGCDetails) {
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perm_gen->print_used_change(perm_gen_prev_used);
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}
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}
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// Track memory usage and detect low memory
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MemoryService::track_memory_usage();
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heap->update_counters();
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if (PrintGCDetails) {
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if (size_policy->print_gc_time_limit_would_be_exceeded()) {
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if (size_policy->gc_time_limit_exceeded()) {
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gclog_or_tty->print_cr(" GC time is exceeding GCTimeLimit "
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"of %d%%", GCTimeLimit);
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} else {
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gclog_or_tty->print_cr(" GC time would exceed GCTimeLimit "
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"of %d%%", GCTimeLimit);
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}
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}
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size_policy->set_print_gc_time_limit_would_be_exceeded(false);
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}
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}
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if (VerifyAfterGC && heap->total_collections() >= VerifyGCStartAt) {
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HandleMark hm; // Discard invalid handles created during verification
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gclog_or_tty->print(" VerifyAfterGC:");
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Universe::verify(false);
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}
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// Re-verify object start arrays
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if (VerifyObjectStartArray &&
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VerifyAfterGC) {
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old_gen->verify_object_start_array();
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perm_gen->verify_object_start_array();
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}
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NOT_PRODUCT(ref_processor()->verify_no_references_recorded());
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if (PrintHeapAtGC) {
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Universe::print_heap_after_gc();
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}
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}
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bool PSMarkSweep::absorb_live_data_from_eden(PSAdaptiveSizePolicy* size_policy,
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PSYoungGen* young_gen,
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PSOldGen* old_gen) {
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MutableSpace* const eden_space = young_gen->eden_space();
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assert(!eden_space->is_empty(), "eden must be non-empty");
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assert(young_gen->virtual_space()->alignment() ==
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old_gen->virtual_space()->alignment(), "alignments do not match");
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if (!(UseAdaptiveSizePolicy && UseAdaptiveGCBoundary)) {
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return false;
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}
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// Both generations must be completely committed.
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if (young_gen->virtual_space()->uncommitted_size() != 0) {
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return false;
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}
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if (old_gen->virtual_space()->uncommitted_size() != 0) {
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return false;
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}
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// Figure out how much to take from eden. Include the average amount promoted
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// in the total; otherwise the next young gen GC will simply bail out to a
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// full GC.
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const size_t alignment = old_gen->virtual_space()->alignment();
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const size_t eden_used = eden_space->used_in_bytes();
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const size_t promoted = (size_t)(size_policy->avg_promoted()->padded_average());
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const size_t absorb_size = align_size_up(eden_used + promoted, alignment);
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const size_t eden_capacity = eden_space->capacity_in_bytes();
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if (absorb_size >= eden_capacity) {
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|
384 |
return false; // Must leave some space in eden.
|
|
385 |
}
|
|
386 |
|
|
387 |
const size_t new_young_size = young_gen->capacity_in_bytes() - absorb_size;
|
|
388 |
if (new_young_size < young_gen->min_gen_size()) {
|
|
389 |
return false; // Respect young gen minimum size.
|
|
390 |
}
|
|
391 |
|
|
392 |
if (TraceAdaptiveGCBoundary && Verbose) {
|
|
393 |
gclog_or_tty->print(" absorbing " SIZE_FORMAT "K: "
|
|
394 |
"eden " SIZE_FORMAT "K->" SIZE_FORMAT "K "
|
|
395 |
"from " SIZE_FORMAT "K, to " SIZE_FORMAT "K "
|
|
396 |
"young_gen " SIZE_FORMAT "K->" SIZE_FORMAT "K ",
|
|
397 |
absorb_size / K,
|
|
398 |
eden_capacity / K, (eden_capacity - absorb_size) / K,
|
|
399 |
young_gen->from_space()->used_in_bytes() / K,
|
|
400 |
young_gen->to_space()->used_in_bytes() / K,
|
|
401 |
young_gen->capacity_in_bytes() / K, new_young_size / K);
|
|
402 |
}
|
|
403 |
|
|
404 |
// Fill the unused part of the old gen.
|
|
405 |
MutableSpace* const old_space = old_gen->object_space();
|
|
406 |
MemRegion old_gen_unused(old_space->top(), old_space->end());
|
|
407 |
|
|
408 |
// If the unused part of the old gen cannot be filled, skip
|
|
409 |
// absorbing eden.
|
|
410 |
if (old_gen_unused.word_size() < SharedHeap::min_fill_size()) {
|
|
411 |
return false;
|
|
412 |
}
|
|
413 |
|
|
414 |
if (!old_gen_unused.is_empty()) {
|
|
415 |
SharedHeap::fill_region_with_object(old_gen_unused);
|
|
416 |
}
|
|
417 |
|
|
418 |
// Take the live data from eden and set both top and end in the old gen to
|
|
419 |
// eden top. (Need to set end because reset_after_change() mangles the region
|
|
420 |
// from end to virtual_space->high() in debug builds).
|
|
421 |
HeapWord* const new_top = eden_space->top();
|
|
422 |
old_gen->virtual_space()->expand_into(young_gen->virtual_space(),
|
|
423 |
absorb_size);
|
|
424 |
young_gen->reset_after_change();
|
|
425 |
old_space->set_top(new_top);
|
|
426 |
old_space->set_end(new_top);
|
|
427 |
old_gen->reset_after_change();
|
|
428 |
|
|
429 |
// Update the object start array for the filler object and the data from eden.
|
|
430 |
ObjectStartArray* const start_array = old_gen->start_array();
|
|
431 |
HeapWord* const start = old_gen_unused.start();
|
|
432 |
for (HeapWord* addr = start; addr < new_top; addr += oop(addr)->size()) {
|
|
433 |
start_array->allocate_block(addr);
|
|
434 |
}
|
|
435 |
|
|
436 |
// Could update the promoted average here, but it is not typically updated at
|
|
437 |
// full GCs and the value to use is unclear. Something like
|
|
438 |
//
|
|
439 |
// cur_promoted_avg + absorb_size / number_of_scavenges_since_last_full_gc.
|
|
440 |
|
|
441 |
size_policy->set_bytes_absorbed_from_eden(absorb_size);
|
|
442 |
return true;
|
|
443 |
}
|
|
444 |
|
|
445 |
void PSMarkSweep::allocate_stacks() {
|
|
446 |
ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
|
|
447 |
assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
|
|
448 |
|
|
449 |
PSYoungGen* young_gen = heap->young_gen();
|
|
450 |
|
|
451 |
MutableSpace* to_space = young_gen->to_space();
|
|
452 |
_preserved_marks = (PreservedMark*)to_space->top();
|
|
453 |
_preserved_count = 0;
|
|
454 |
|
|
455 |
// We want to calculate the size in bytes first.
|
|
456 |
_preserved_count_max = pointer_delta(to_space->end(), to_space->top(), sizeof(jbyte));
|
|
457 |
// Now divide by the size of a PreservedMark
|
|
458 |
_preserved_count_max /= sizeof(PreservedMark);
|
|
459 |
|
|
460 |
_preserved_mark_stack = NULL;
|
|
461 |
_preserved_oop_stack = NULL;
|
|
462 |
|
|
463 |
_marking_stack = new (ResourceObj::C_HEAP) GrowableArray<oop>(4000, true);
|
|
464 |
|
|
465 |
int size = SystemDictionary::number_of_classes() * 2;
|
|
466 |
_revisit_klass_stack = new (ResourceObj::C_HEAP) GrowableArray<Klass*>(size, true);
|
|
467 |
}
|
|
468 |
|
|
469 |
|
|
470 |
void PSMarkSweep::deallocate_stacks() {
|
|
471 |
if (_preserved_oop_stack) {
|
|
472 |
delete _preserved_mark_stack;
|
|
473 |
_preserved_mark_stack = NULL;
|
|
474 |
delete _preserved_oop_stack;
|
|
475 |
_preserved_oop_stack = NULL;
|
|
476 |
}
|
|
477 |
|
|
478 |
delete _marking_stack;
|
|
479 |
delete _revisit_klass_stack;
|
|
480 |
}
|
|
481 |
|
|
482 |
void PSMarkSweep::mark_sweep_phase1(bool clear_all_softrefs) {
|
|
483 |
// Recursively traverse all live objects and mark them
|
|
484 |
EventMark m("1 mark object");
|
|
485 |
TraceTime tm("phase 1", PrintGCDetails && Verbose, true, gclog_or_tty);
|
|
486 |
trace(" 1");
|
|
487 |
|
|
488 |
ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
|
|
489 |
assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
|
|
490 |
|
|
491 |
// General strong roots.
|
|
492 |
Universe::oops_do(mark_and_push_closure());
|
|
493 |
ReferenceProcessor::oops_do(mark_and_push_closure());
|
|
494 |
JNIHandles::oops_do(mark_and_push_closure()); // Global (strong) JNI handles
|
|
495 |
Threads::oops_do(mark_and_push_closure());
|
|
496 |
ObjectSynchronizer::oops_do(mark_and_push_closure());
|
|
497 |
FlatProfiler::oops_do(mark_and_push_closure());
|
|
498 |
Management::oops_do(mark_and_push_closure());
|
|
499 |
JvmtiExport::oops_do(mark_and_push_closure());
|
|
500 |
SystemDictionary::always_strong_oops_do(mark_and_push_closure());
|
|
501 |
vmSymbols::oops_do(mark_and_push_closure());
|
|
502 |
|
|
503 |
// Flush marking stack.
|
|
504 |
follow_stack();
|
|
505 |
|
|
506 |
// Process reference objects found during marking
|
|
507 |
|
|
508 |
// Skipping the reference processing for VerifyParallelOldWithMarkSweep
|
|
509 |
// affects the marking (makes it different).
|
|
510 |
{
|
|
511 |
ReferencePolicy *soft_ref_policy;
|
|
512 |
if (clear_all_softrefs) {
|
|
513 |
soft_ref_policy = new AlwaysClearPolicy();
|
|
514 |
} else {
|
|
515 |
#ifdef COMPILER2
|
|
516 |
soft_ref_policy = new LRUMaxHeapPolicy();
|
|
517 |
#else
|
|
518 |
soft_ref_policy = new LRUCurrentHeapPolicy();
|
|
519 |
#endif // COMPILER2
|
|
520 |
}
|
|
521 |
assert(soft_ref_policy != NULL,"No soft reference policy");
|
|
522 |
ref_processor()->process_discovered_references(
|
|
523 |
soft_ref_policy, is_alive_closure(), mark_and_push_closure(),
|
|
524 |
follow_stack_closure(), NULL);
|
|
525 |
}
|
|
526 |
|
|
527 |
// Follow system dictionary roots and unload classes
|
|
528 |
bool purged_class = SystemDictionary::do_unloading(is_alive_closure());
|
|
529 |
|
|
530 |
// Follow code cache roots
|
|
531 |
CodeCache::do_unloading(is_alive_closure(), mark_and_push_closure(),
|
|
532 |
purged_class);
|
|
533 |
follow_stack(); // Flush marking stack
|
|
534 |
|
|
535 |
// Update subklass/sibling/implementor links of live klasses
|
|
536 |
follow_weak_klass_links();
|
|
537 |
assert(_marking_stack->is_empty(), "just drained");
|
|
538 |
|
|
539 |
// Visit symbol and interned string tables and delete unmarked oops
|
|
540 |
SymbolTable::unlink(is_alive_closure());
|
|
541 |
StringTable::unlink(is_alive_closure());
|
|
542 |
|
|
543 |
assert(_marking_stack->is_empty(), "stack should be empty by now");
|
|
544 |
}
|
|
545 |
|
|
546 |
|
|
547 |
void PSMarkSweep::mark_sweep_phase2() {
|
|
548 |
EventMark m("2 compute new addresses");
|
|
549 |
TraceTime tm("phase 2", PrintGCDetails && Verbose, true, gclog_or_tty);
|
|
550 |
trace("2");
|
|
551 |
|
|
552 |
// Now all live objects are marked, compute the new object addresses.
|
|
553 |
|
|
554 |
// It is imperative that we traverse perm_gen LAST. If dead space is
|
|
555 |
// allowed a range of dead object may get overwritten by a dead int
|
|
556 |
// array. If perm_gen is not traversed last a klassOop may get
|
|
557 |
// overwritten. This is fine since it is dead, but if the class has dead
|
|
558 |
// instances we have to skip them, and in order to find their size we
|
|
559 |
// need the klassOop!
|
|
560 |
//
|
|
561 |
// It is not required that we traverse spaces in the same order in
|
|
562 |
// phase2, phase3 and phase4, but the ValidateMarkSweep live oops
|
|
563 |
// tracking expects us to do so. See comment under phase4.
|
|
564 |
|
|
565 |
ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
|
|
566 |
assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
|
|
567 |
|
|
568 |
PSOldGen* old_gen = heap->old_gen();
|
|
569 |
PSPermGen* perm_gen = heap->perm_gen();
|
|
570 |
|
|
571 |
// Begin compacting into the old gen
|
|
572 |
PSMarkSweepDecorator::set_destination_decorator_tenured();
|
|
573 |
|
|
574 |
// This will also compact the young gen spaces.
|
|
575 |
old_gen->precompact();
|
|
576 |
|
|
577 |
// Compact the perm gen into the perm gen
|
|
578 |
PSMarkSweepDecorator::set_destination_decorator_perm_gen();
|
|
579 |
|
|
580 |
perm_gen->precompact();
|
|
581 |
}
|
|
582 |
|
|
583 |
// This should be moved to the shared markSweep code!
|
|
584 |
class PSAlwaysTrueClosure: public BoolObjectClosure {
|
|
585 |
public:
|
|
586 |
void do_object(oop p) { ShouldNotReachHere(); }
|
|
587 |
bool do_object_b(oop p) { return true; }
|
|
588 |
};
|
|
589 |
static PSAlwaysTrueClosure always_true;
|
|
590 |
|
|
591 |
void PSMarkSweep::mark_sweep_phase3() {
|
|
592 |
// Adjust the pointers to reflect the new locations
|
|
593 |
EventMark m("3 adjust pointers");
|
|
594 |
TraceTime tm("phase 3", PrintGCDetails && Verbose, true, gclog_or_tty);
|
|
595 |
trace("3");
|
|
596 |
|
|
597 |
ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
|
|
598 |
assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
|
|
599 |
|
|
600 |
PSYoungGen* young_gen = heap->young_gen();
|
|
601 |
PSOldGen* old_gen = heap->old_gen();
|
|
602 |
PSPermGen* perm_gen = heap->perm_gen();
|
|
603 |
|
|
604 |
// General strong roots.
|
|
605 |
Universe::oops_do(adjust_root_pointer_closure());
|
|
606 |
ReferenceProcessor::oops_do(adjust_root_pointer_closure());
|
|
607 |
JNIHandles::oops_do(adjust_root_pointer_closure()); // Global (strong) JNI handles
|
|
608 |
Threads::oops_do(adjust_root_pointer_closure());
|
|
609 |
ObjectSynchronizer::oops_do(adjust_root_pointer_closure());
|
|
610 |
FlatProfiler::oops_do(adjust_root_pointer_closure());
|
|
611 |
Management::oops_do(adjust_root_pointer_closure());
|
|
612 |
JvmtiExport::oops_do(adjust_root_pointer_closure());
|
|
613 |
// SO_AllClasses
|
|
614 |
SystemDictionary::oops_do(adjust_root_pointer_closure());
|
|
615 |
vmSymbols::oops_do(adjust_root_pointer_closure());
|
|
616 |
|
|
617 |
// Now adjust pointers in remaining weak roots. (All of which should
|
|
618 |
// have been cleared if they pointed to non-surviving objects.)
|
|
619 |
// Global (weak) JNI handles
|
|
620 |
JNIHandles::weak_oops_do(&always_true, adjust_root_pointer_closure());
|
|
621 |
|
|
622 |
CodeCache::oops_do(adjust_pointer_closure());
|
|
623 |
SymbolTable::oops_do(adjust_root_pointer_closure());
|
|
624 |
StringTable::oops_do(adjust_root_pointer_closure());
|
|
625 |
ref_processor()->weak_oops_do(adjust_root_pointer_closure());
|
|
626 |
PSScavenge::reference_processor()->weak_oops_do(adjust_root_pointer_closure());
|
|
627 |
|
|
628 |
adjust_marks();
|
|
629 |
|
|
630 |
young_gen->adjust_pointers();
|
|
631 |
old_gen->adjust_pointers();
|
|
632 |
perm_gen->adjust_pointers();
|
|
633 |
}
|
|
634 |
|
|
635 |
void PSMarkSweep::mark_sweep_phase4() {
|
|
636 |
EventMark m("4 compact heap");
|
|
637 |
TraceTime tm("phase 4", PrintGCDetails && Verbose, true, gclog_or_tty);
|
|
638 |
trace("4");
|
|
639 |
|
|
640 |
// All pointers are now adjusted, move objects accordingly
|
|
641 |
|
|
642 |
// It is imperative that we traverse perm_gen first in phase4. All
|
|
643 |
// classes must be allocated earlier than their instances, and traversing
|
|
644 |
// perm_gen first makes sure that all klassOops have moved to their new
|
|
645 |
// location before any instance does a dispatch through it's klass!
|
|
646 |
ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
|
|
647 |
assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
|
|
648 |
|
|
649 |
PSYoungGen* young_gen = heap->young_gen();
|
|
650 |
PSOldGen* old_gen = heap->old_gen();
|
|
651 |
PSPermGen* perm_gen = heap->perm_gen();
|
|
652 |
|
|
653 |
perm_gen->compact();
|
|
654 |
old_gen->compact();
|
|
655 |
young_gen->compact();
|
|
656 |
}
|
|
657 |
|
|
658 |
jlong PSMarkSweep::millis_since_last_gc() {
|
|
659 |
jlong ret_val = os::javaTimeMillis() - _time_of_last_gc;
|
|
660 |
// XXX See note in genCollectedHeap::millis_since_last_gc().
|
|
661 |
if (ret_val < 0) {
|
|
662 |
NOT_PRODUCT(warning("time warp: %d", ret_val);)
|
|
663 |
return 0;
|
|
664 |
}
|
|
665 |
return ret_val;
|
|
666 |
}
|
|
667 |
|
|
668 |
void PSMarkSweep::reset_millis_since_last_gc() {
|
|
669 |
_time_of_last_gc = os::javaTimeMillis();
|
|
670 |
}
|