jdk8-mips64-public/hotspot: src/share/vm/gc_implementation/parallelScavenge/psMarkSweep.cpp@3582bf76420e (annotated)

src/share/vm/gc_implementation/parallelScavenge/psMarkSweep.cpp@3582bf76420e (annotated)

src/share/vm/gc_implementation/parallelScavenge/psMarkSweep.cpp

Thu, 27 Jan 2011 16:11:27 -0800

author: coleenp
date: Thu, 27 Jan 2011 16:11:27 -0800
changeset 2497: 3582bf76420e
parent 2467: 9afee0b9fc1d
child 2651: 92da084fefc9
permissions: -rw-r--r--

6990754: Use native memory and reference counting to implement SymbolTable
Summary: move symbols from permgen into C heap and reference count them
Reviewed-by: never, acorn, jmasa, stefank

 /*
  * Copyright (c) 2001, 2010, 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/psPermGen.hpp"
 #include "gc_implementation/parallelScavenge/psScavenge.hpp"
 #include "gc_implementation/parallelScavenge/psYoungGen.hpp"
 #include "gc_implementation/shared/isGCActiveMark.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;
 unsigned int        PSMarkSweep::_total_invocations = 0;
 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,
                                           true,    // atomic_discovery
                                           false);  // mt_discovery
   _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();
   int count = (maximum_heap_compaction)?1:MarkSweepAlwaysCompactCount;
   IntFlagSetting 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.
 void 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;
   }
   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();
   PSPermGen* perm_gen = heap->perm_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());
   if (PrintHeapAtGC) {
     Universe::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
     gclog_or_tty->print(" VerifyBeforeGC:");
     Universe::verify(true);
   }
   // Verify object start arrays
   if (VerifyObjectStartArray &&
       VerifyBeforeGC) {
     old_gen->verify_object_start_array();
     perm_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;
     const bool is_system_gc = gc_cause == GCCause::_java_lang_system_gc;
     // This is useful for debugging but don't change the output the
     // the customer sees.
     const char* gc_cause_str = "Full GC";
     if (is_system_gc && PrintGCDetails) {
       gc_cause_str = "Full GC (System)";
     }
     gclog_or_tty->date_stamp(PrintGC && PrintGCDateStamps);
     TraceCPUTime tcpu(PrintGCDetails, true, gclog_or_tty);
     TraceTime t1(gc_cause_str, PrintGC, !PrintGCDetails, gclog_or_tty);
     TraceCollectorStats tcs(counters());
     TraceMemoryManagerStats tms(true /* Full GC */);
     if (TraceGen1Time) accumulated_time()->start();
     // Let the size policy know we're starting
     size_policy->major_collection_begin();
     // When collecting the permanent generation methodOops may be moving,
     // so we either have to flush all bcp data or convert it into bci.
     CodeCache::gc_prologue();
     Threads::gc_prologue();
     BiasedLocking::preserve_marks();
     // Capture heap size before collection for printing.
     size_t prev_used = heap->used();
     // Capture perm gen size before collection for sizing.
     size_t perm_gen_prev_used = perm_gen->used_in_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();
     NOT_PRODUCT(ref_processor()->verify_no_references_recorded());
     COMPILER2_PRESENT(DerivedPointerTable::clear());
     ref_processor()->enable_discovery();
     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();
       MemRegion perm_mr = heap->perm_gen()->reserved();
       assert(perm_mr.end() <= old_mr.start(), "Generations out of order");
       if (young_gen_empty) {
         modBS->clear(MemRegion(perm_mr.start(), old_mr.end()));
       } else {
         modBS->invalidate(MemRegion(perm_mr.start(), old_mr.end()));
       }
     }
     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"
             " perm_gen_capacity: %d ",
             old_gen->capacity_in_bytes(), young_gen->capacity_in_bytes(),
             perm_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 max_eden_size = young_gen->max_size() -
           young_gen->from_space()->capacity_in_bytes() -
           young_gen->to_space()->capacity_in_bytes();
         size_policy->compute_generation_free_space(young_gen->used_in_bytes(),
                                  young_gen->eden_space()->used_in_bytes(),
                                  old_gen->used_in_bytes(),
                                  perm_gen->used_in_bytes(),
                                  young_gen->eden_space()->capacity_in_bytes(),
                                  old_gen->max_gen_size(),
                                  max_eden_size,
                                  true /* full gc*/,
                                  gc_cause,
                                  heap->collector_policy());
         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 perm gen, so we'll resize it here.
     perm_gen->compute_new_size(perm_gen_prev_used);
     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);
       // Do perm gen after heap becase prev_used does
       // not include the perm gen (done this way in the other
       // collectors).
       if (PrintGCDetails) {
         perm_gen->print_used_change(perm_gen_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
     gclog_or_tty->print(" VerifyAfterGC:");
     Universe::verify(false);
   }
   // Re-verify object start arrays
   if (VerifyObjectStartArray &&
       VerifyAfterGC) {
     old_gen->verify_object_start_array();
     perm_gen->verify_object_start_array();
   }
   if (ZapUnusedHeapArea) {
     old_gen->object_space()->check_mangled_unused_area_complete();
     perm_gen->object_space()->check_mangled_unused_area_complete();
   }
   NOT_PRODUCT(ref_processor()->verify_no_references_recorded());
   if (PrintHeapAtGC) {
     Universe::print_heap_after_gc();
   }
   heap->post_full_gc_dump();
 #ifdef TRACESPINNING
   ParallelTaskTerminator::print_termination_counts();
 #endif
 }
 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);
   _revisit_klass_stack.clear(true);
   _revisit_mdo_stack.clear(true);
 }
 void PSMarkSweep::mark_sweep_phase1(bool clear_all_softrefs) {
   // Recursively traverse all live objects and mark them
   EventMark m("1 mark object");
   TraceTime tm("phase 1", PrintGCDetails && Verbose, true, gclog_or_tty);
   trace(" 1");
   ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
   assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
   // General strong roots.
   {
     ParallelScavengeHeap::ParStrongRootsScope psrs;
     Universe::oops_do(mark_and_push_closure());
     ReferenceProcessor::oops_do(mark_and_push_closure());
     JNIHandles::oops_do(mark_and_push_closure());   // Global (strong) JNI handles
     CodeBlobToOopClosure each_active_code_blob(mark_and_push_closure(), /*do_marking=*/ true);
     Threads::oops_do(mark_and_push_closure(), &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());
     // 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);
   }
   // Follow system dictionary roots and unload classes
   bool purged_class = SystemDictionary::do_unloading(is_alive_closure());
   // Follow code cache roots
   CodeCache::do_unloading(is_alive_closure(), mark_and_push_closure(),
                           purged_class);
   follow_stack(); // Flush marking stack
   // Update subklass/sibling/implementor links of live klasses
   follow_weak_klass_links();
   assert(_marking_stack.is_empty(), "just drained");
   // Visit memoized mdo's and clear unmarked weak refs
   follow_mdo_weak_refs();
   assert(_marking_stack.is_empty(), "just drained");
   // Visit interned string tables and delete unmarked oops
   StringTable::unlink(is_alive_closure());
   // Clean up unreferenced symbols in symbol table.
   SymbolTable::unlink();
   assert(_marking_stack.is_empty(), "stack should be empty by now");
 }
 void PSMarkSweep::mark_sweep_phase2() {
   EventMark m("2 compute new addresses");
   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 imperative that we traverse perm_gen LAST. If dead space is
   // allowed a range of dead object may get overwritten by a dead int
   // array. If perm_gen is not traversed last a klassOop may get
   // overwritten. This is fine since it is dead, but if the class has dead
   // instances we have to skip them, and in order to find their size we
   // need the klassOop!
   //
   // 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();
   PSPermGen* perm_gen = heap->perm_gen();
   // Begin compacting into the old gen
   PSMarkSweepDecorator::set_destination_decorator_tenured();
   // This will also compact the young gen spaces.
   old_gen->precompact();
   // Compact the perm gen into the perm gen
   PSMarkSweepDecorator::set_destination_decorator_perm_gen();
   perm_gen->precompact();
 }
 // This should be moved to the shared markSweep code!
 class PSAlwaysTrueClosure: public BoolObjectClosure {
 public:
   void do_object(oop p) { ShouldNotReachHere(); }
   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
   EventMark m("3 adjust pointers");
   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();
   PSPermGen* perm_gen = heap->perm_gen();
   // General strong roots.
   Universe::oops_do(adjust_root_pointer_closure());
   ReferenceProcessor::oops_do(adjust_root_pointer_closure());
   JNIHandles::oops_do(adjust_root_pointer_closure());   // Global (strong) JNI handles
   Threads::oops_do(adjust_root_pointer_closure(), NULL);
   ObjectSynchronizer::oops_do(adjust_root_pointer_closure());
   FlatProfiler::oops_do(adjust_root_pointer_closure());
   Management::oops_do(adjust_root_pointer_closure());
   JvmtiExport::oops_do(adjust_root_pointer_closure());
   // SO_AllClasses
   SystemDictionary::oops_do(adjust_root_pointer_closure());
   //CodeCache::scavenge_root_nmethods_oops_do(adjust_root_pointer_closure());
   // 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_root_pointer_closure());
   CodeCache::oops_do(adjust_pointer_closure());
   StringTable::oops_do(adjust_root_pointer_closure());
   ref_processor()->weak_oops_do(adjust_root_pointer_closure());
   PSScavenge::reference_processor()->weak_oops_do(adjust_root_pointer_closure());
   adjust_marks();
   young_gen->adjust_pointers();
   old_gen->adjust_pointers();
   perm_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
   // It is imperative that we traverse perm_gen first in phase4. All
   // classes must be allocated earlier than their instances, and traversing
   // perm_gen first makes sure that all klassOops have moved to their new
   // location before any instance does a dispatch through it's klass!
   ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
   assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
   PSYoungGen* young_gen = heap->young_gen();
   PSOldGen* old_gen = heap->old_gen();
   PSPermGen* perm_gen = heap->perm_gen();
   perm_gen->compact();
   old_gen->compact();
   young_gen->compact();
 }
 jlong PSMarkSweep::millis_since_last_gc() {
   jlong ret_val = os::javaTimeMillis() - _time_of_last_gc;
   // XXX See note in genCollectedHeap::millis_since_last_gc().
   if (ret_val < 0) {
     NOT_PRODUCT(warning("time warp: %d", ret_val);)
     return 0;
   }
   return ret_val;
 }
 void PSMarkSweep::reset_millis_since_last_gc() {
   _time_of_last_gc = os::javaTimeMillis();
 }

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/gc_implementation/parallelScavenge/psMarkSweep.cpp@3582bf76420e (annotated)

src/share/vm/gc_implementation/parallelScavenge/psMarkSweep.cpp