029aa9ef92
It is intended to bring memory usage down on idle notifications. R=erik.corry@gmail.com BUG=v8:1726 Review URL: https://chromiumcodereview.appspot.com/9323079 git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10616 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
927 lines
30 KiB
C++
927 lines
30 KiB
C++
// Copyright 2011 the V8 project authors. All rights reserved.
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// Redistribution and use in source and binary forms, with or without
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// modification, are permitted provided that the following conditions are
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// met:
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//
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// * Redistributions of source code must retain the above copyright
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// notice, this list of conditions and the following disclaimer.
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// * Redistributions in binary form must reproduce the above
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// copyright notice, this list of conditions and the following
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// disclaimer in the documentation and/or other materials provided
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// with the distribution.
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// * Neither the name of Google Inc. nor the names of its
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// contributors may be used to endorse or promote products derived
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// from this software without specific prior written permission.
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//
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// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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#include "v8.h"
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#include "incremental-marking.h"
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#include "code-stubs.h"
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#include "compilation-cache.h"
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#include "v8conversions.h"
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namespace v8 {
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namespace internal {
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IncrementalMarking::IncrementalMarking(Heap* heap)
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: heap_(heap),
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state_(STOPPED),
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marking_deque_memory_(NULL),
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marking_deque_memory_committed_(false),
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steps_count_(0),
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steps_took_(0),
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longest_step_(0.0),
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old_generation_space_available_at_start_of_incremental_(0),
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old_generation_space_used_at_start_of_incremental_(0),
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steps_count_since_last_gc_(0),
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steps_took_since_last_gc_(0),
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should_hurry_(false),
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allocation_marking_factor_(0),
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allocated_(0),
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no_marking_scope_depth_(0) {
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}
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void IncrementalMarking::TearDown() {
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delete marking_deque_memory_;
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}
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void IncrementalMarking::RecordWriteSlow(HeapObject* obj,
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Object** slot,
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Object* value) {
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if (BaseRecordWrite(obj, slot, value) && is_compacting_ && slot != NULL) {
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MarkBit obj_bit = Marking::MarkBitFrom(obj);
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if (Marking::IsBlack(obj_bit)) {
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// Object is not going to be rescanned we need to record the slot.
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heap_->mark_compact_collector()->RecordSlot(
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HeapObject::RawField(obj, 0), slot, value);
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}
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}
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}
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void IncrementalMarking::RecordWriteFromCode(HeapObject* obj,
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Object* value,
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Isolate* isolate) {
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ASSERT(obj->IsHeapObject());
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// Fast cases should already be covered by RecordWriteStub.
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ASSERT(value->IsHeapObject());
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ASSERT(!value->IsHeapNumber());
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ASSERT(!value->IsString() ||
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value->IsConsString() ||
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value->IsSlicedString());
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ASSERT(Marking::IsWhite(Marking::MarkBitFrom(HeapObject::cast(value))));
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IncrementalMarking* marking = isolate->heap()->incremental_marking();
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ASSERT(!marking->is_compacting_);
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marking->RecordWrite(obj, NULL, value);
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}
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void IncrementalMarking::RecordWriteForEvacuationFromCode(HeapObject* obj,
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Object** slot,
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Isolate* isolate) {
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IncrementalMarking* marking = isolate->heap()->incremental_marking();
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ASSERT(marking->is_compacting_);
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marking->RecordWrite(obj, slot, *slot);
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}
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void IncrementalMarking::RecordCodeTargetPatch(Code* host,
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Address pc,
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HeapObject* value) {
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if (IsMarking()) {
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RelocInfo rinfo(pc, RelocInfo::CODE_TARGET, 0, host);
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RecordWriteIntoCode(host, &rinfo, value);
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}
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}
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void IncrementalMarking::RecordCodeTargetPatch(Address pc, HeapObject* value) {
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if (IsMarking()) {
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Code* host = heap_->isolate()->inner_pointer_to_code_cache()->
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GcSafeFindCodeForInnerPointer(pc);
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RelocInfo rinfo(pc, RelocInfo::CODE_TARGET, 0, host);
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RecordWriteIntoCode(host, &rinfo, value);
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}
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}
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void IncrementalMarking::RecordWriteOfCodeEntrySlow(JSFunction* host,
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Object** slot,
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Code* value) {
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if (BaseRecordWrite(host, slot, value) && is_compacting_) {
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ASSERT(slot != NULL);
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heap_->mark_compact_collector()->
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RecordCodeEntrySlot(reinterpret_cast<Address>(slot), value);
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}
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}
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void IncrementalMarking::RecordWriteIntoCodeSlow(HeapObject* obj,
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RelocInfo* rinfo,
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Object* value) {
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MarkBit value_bit = Marking::MarkBitFrom(HeapObject::cast(value));
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if (Marking::IsWhite(value_bit)) {
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MarkBit obj_bit = Marking::MarkBitFrom(obj);
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if (Marking::IsBlack(obj_bit)) {
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BlackToGreyAndUnshift(obj, obj_bit);
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RestartIfNotMarking();
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}
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// Object is either grey or white. It will be scanned if survives.
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return;
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}
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if (is_compacting_) {
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MarkBit obj_bit = Marking::MarkBitFrom(obj);
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if (Marking::IsBlack(obj_bit)) {
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// Object is not going to be rescanned. We need to record the slot.
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heap_->mark_compact_collector()->RecordRelocSlot(rinfo,
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Code::cast(value));
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}
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}
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}
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class IncrementalMarkingMarkingVisitor : public ObjectVisitor {
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public:
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IncrementalMarkingMarkingVisitor(Heap* heap,
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IncrementalMarking* incremental_marking)
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: heap_(heap),
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incremental_marking_(incremental_marking) {
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}
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void VisitEmbeddedPointer(RelocInfo* rinfo) {
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ASSERT(rinfo->rmode() == RelocInfo::EMBEDDED_OBJECT);
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Object* target = rinfo->target_object();
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if (target->NonFailureIsHeapObject()) {
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heap_->mark_compact_collector()->RecordRelocSlot(rinfo, target);
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MarkObject(target);
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}
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}
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void VisitCodeTarget(RelocInfo* rinfo) {
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ASSERT(RelocInfo::IsCodeTarget(rinfo->rmode()));
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Object* target = Code::GetCodeFromTargetAddress(rinfo->target_address());
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heap_->mark_compact_collector()->RecordRelocSlot(rinfo, Code::cast(target));
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MarkObject(target);
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}
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void VisitDebugTarget(RelocInfo* rinfo) {
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ASSERT((RelocInfo::IsJSReturn(rinfo->rmode()) &&
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rinfo->IsPatchedReturnSequence()) ||
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(RelocInfo::IsDebugBreakSlot(rinfo->rmode()) &&
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rinfo->IsPatchedDebugBreakSlotSequence()));
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Object* target = Code::GetCodeFromTargetAddress(rinfo->call_address());
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heap_->mark_compact_collector()->RecordRelocSlot(rinfo, Code::cast(target));
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MarkObject(target);
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}
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void VisitCodeEntry(Address entry_address) {
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Object* target = Code::GetObjectFromEntryAddress(entry_address);
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heap_->mark_compact_collector()->
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RecordCodeEntrySlot(entry_address, Code::cast(target));
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MarkObject(target);
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}
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void VisitPointer(Object** p) {
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Object* obj = *p;
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if (obj->NonFailureIsHeapObject()) {
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heap_->mark_compact_collector()->RecordSlot(p, p, obj);
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MarkObject(obj);
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}
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}
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void VisitPointers(Object** start, Object** end) {
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for (Object** p = start; p < end; p++) {
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Object* obj = *p;
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if (obj->NonFailureIsHeapObject()) {
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heap_->mark_compact_collector()->RecordSlot(start, p, obj);
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MarkObject(obj);
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}
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}
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}
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private:
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// Mark object pointed to by p.
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INLINE(void MarkObject(Object* obj)) {
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HeapObject* heap_object = HeapObject::cast(obj);
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MarkBit mark_bit = Marking::MarkBitFrom(heap_object);
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if (mark_bit.data_only()) {
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if (incremental_marking_->MarkBlackOrKeepGrey(mark_bit)) {
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MemoryChunk::IncrementLiveBytesFromGC(heap_object->address(),
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heap_object->Size());
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}
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} else if (Marking::IsWhite(mark_bit)) {
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incremental_marking_->WhiteToGreyAndPush(heap_object, mark_bit);
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}
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}
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Heap* heap_;
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IncrementalMarking* incremental_marking_;
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};
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class IncrementalMarkingRootMarkingVisitor : public ObjectVisitor {
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public:
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IncrementalMarkingRootMarkingVisitor(Heap* heap,
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IncrementalMarking* incremental_marking)
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: heap_(heap),
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incremental_marking_(incremental_marking) {
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}
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void VisitPointer(Object** p) {
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MarkObjectByPointer(p);
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}
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void VisitPointers(Object** start, Object** end) {
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for (Object** p = start; p < end; p++) MarkObjectByPointer(p);
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}
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private:
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void MarkObjectByPointer(Object** p) {
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Object* obj = *p;
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if (!obj->IsHeapObject()) return;
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HeapObject* heap_object = HeapObject::cast(obj);
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MarkBit mark_bit = Marking::MarkBitFrom(heap_object);
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if (mark_bit.data_only()) {
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if (incremental_marking_->MarkBlackOrKeepGrey(mark_bit)) {
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MemoryChunk::IncrementLiveBytesFromGC(heap_object->address(),
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heap_object->Size());
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}
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} else {
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if (Marking::IsWhite(mark_bit)) {
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incremental_marking_->WhiteToGreyAndPush(heap_object, mark_bit);
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}
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}
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}
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Heap* heap_;
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IncrementalMarking* incremental_marking_;
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};
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void IncrementalMarking::SetOldSpacePageFlags(MemoryChunk* chunk,
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bool is_marking,
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bool is_compacting) {
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if (is_marking) {
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chunk->SetFlag(MemoryChunk::POINTERS_TO_HERE_ARE_INTERESTING);
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chunk->SetFlag(MemoryChunk::POINTERS_FROM_HERE_ARE_INTERESTING);
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// It's difficult to filter out slots recorded for large objects.
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if (chunk->owner()->identity() == LO_SPACE &&
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chunk->size() > static_cast<size_t>(Page::kPageSize) &&
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is_compacting) {
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chunk->SetFlag(MemoryChunk::RESCAN_ON_EVACUATION);
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}
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} else if (chunk->owner()->identity() == CELL_SPACE ||
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chunk->scan_on_scavenge()) {
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chunk->ClearFlag(MemoryChunk::POINTERS_TO_HERE_ARE_INTERESTING);
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chunk->ClearFlag(MemoryChunk::POINTERS_FROM_HERE_ARE_INTERESTING);
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} else {
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chunk->ClearFlag(MemoryChunk::POINTERS_TO_HERE_ARE_INTERESTING);
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chunk->SetFlag(MemoryChunk::POINTERS_FROM_HERE_ARE_INTERESTING);
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}
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}
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void IncrementalMarking::SetNewSpacePageFlags(NewSpacePage* chunk,
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bool is_marking) {
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chunk->SetFlag(MemoryChunk::POINTERS_TO_HERE_ARE_INTERESTING);
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if (is_marking) {
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chunk->SetFlag(MemoryChunk::POINTERS_FROM_HERE_ARE_INTERESTING);
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} else {
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chunk->ClearFlag(MemoryChunk::POINTERS_FROM_HERE_ARE_INTERESTING);
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}
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chunk->SetFlag(MemoryChunk::SCAN_ON_SCAVENGE);
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}
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void IncrementalMarking::DeactivateIncrementalWriteBarrierForSpace(
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PagedSpace* space) {
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PageIterator it(space);
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while (it.has_next()) {
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Page* p = it.next();
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SetOldSpacePageFlags(p, false, false);
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}
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}
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void IncrementalMarking::DeactivateIncrementalWriteBarrierForSpace(
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NewSpace* space) {
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NewSpacePageIterator it(space);
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while (it.has_next()) {
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NewSpacePage* p = it.next();
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SetNewSpacePageFlags(p, false);
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}
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}
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void IncrementalMarking::DeactivateIncrementalWriteBarrier() {
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DeactivateIncrementalWriteBarrierForSpace(heap_->old_pointer_space());
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DeactivateIncrementalWriteBarrierForSpace(heap_->old_data_space());
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DeactivateIncrementalWriteBarrierForSpace(heap_->cell_space());
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DeactivateIncrementalWriteBarrierForSpace(heap_->map_space());
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DeactivateIncrementalWriteBarrierForSpace(heap_->code_space());
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DeactivateIncrementalWriteBarrierForSpace(heap_->new_space());
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LargePage* lop = heap_->lo_space()->first_page();
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while (lop->is_valid()) {
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SetOldSpacePageFlags(lop, false, false);
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lop = lop->next_page();
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}
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}
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void IncrementalMarking::ActivateIncrementalWriteBarrier(PagedSpace* space) {
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PageIterator it(space);
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while (it.has_next()) {
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Page* p = it.next();
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SetOldSpacePageFlags(p, true, is_compacting_);
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}
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}
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void IncrementalMarking::ActivateIncrementalWriteBarrier(NewSpace* space) {
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NewSpacePageIterator it(space->ToSpaceStart(), space->ToSpaceEnd());
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while (it.has_next()) {
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NewSpacePage* p = it.next();
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SetNewSpacePageFlags(p, true);
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}
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}
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void IncrementalMarking::ActivateIncrementalWriteBarrier() {
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ActivateIncrementalWriteBarrier(heap_->old_pointer_space());
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ActivateIncrementalWriteBarrier(heap_->old_data_space());
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ActivateIncrementalWriteBarrier(heap_->cell_space());
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ActivateIncrementalWriteBarrier(heap_->map_space());
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ActivateIncrementalWriteBarrier(heap_->code_space());
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ActivateIncrementalWriteBarrier(heap_->new_space());
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LargePage* lop = heap_->lo_space()->first_page();
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while (lop->is_valid()) {
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SetOldSpacePageFlags(lop, true, is_compacting_);
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lop = lop->next_page();
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}
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}
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bool IncrementalMarking::WorthActivating() {
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#ifndef DEBUG
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static const intptr_t kActivationThreshold = 8 * MB;
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#else
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// TODO(gc) consider setting this to some low level so that some
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// debug tests run with incremental marking and some without.
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static const intptr_t kActivationThreshold = 0;
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#endif
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return !FLAG_expose_gc &&
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FLAG_incremental_marking &&
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!Serializer::enabled() &&
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heap_->PromotedSpaceSize() > kActivationThreshold;
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}
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void IncrementalMarking::ActivateGeneratedStub(Code* stub) {
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ASSERT(RecordWriteStub::GetMode(stub) ==
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RecordWriteStub::STORE_BUFFER_ONLY);
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if (!IsMarking()) {
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// Initially stub is generated in STORE_BUFFER_ONLY mode thus
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// we don't need to do anything if incremental marking is
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// not active.
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} else if (IsCompacting()) {
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RecordWriteStub::Patch(stub, RecordWriteStub::INCREMENTAL_COMPACTION);
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} else {
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RecordWriteStub::Patch(stub, RecordWriteStub::INCREMENTAL);
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}
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}
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static void PatchIncrementalMarkingRecordWriteStubs(
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Heap* heap, RecordWriteStub::Mode mode) {
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UnseededNumberDictionary* stubs = heap->code_stubs();
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int capacity = stubs->Capacity();
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for (int i = 0; i < capacity; i++) {
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Object* k = stubs->KeyAt(i);
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if (stubs->IsKey(k)) {
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uint32_t key = NumberToUint32(k);
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if (CodeStub::MajorKeyFromKey(key) ==
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CodeStub::RecordWrite) {
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Object* e = stubs->ValueAt(i);
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if (e->IsCode()) {
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RecordWriteStub::Patch(Code::cast(e), mode);
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}
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}
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}
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}
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}
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void IncrementalMarking::EnsureMarkingDequeIsCommitted() {
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if (marking_deque_memory_ == NULL) {
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marking_deque_memory_ = new VirtualMemory(4 * MB);
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}
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if (!marking_deque_memory_committed_) {
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bool success = marking_deque_memory_->Commit(
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reinterpret_cast<Address>(marking_deque_memory_->address()),
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marking_deque_memory_->size(),
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false); // Not executable.
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CHECK(success);
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marking_deque_memory_committed_ = true;
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}
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}
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void IncrementalMarking::UncommitMarkingDeque() {
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if (state_ == STOPPED && marking_deque_memory_committed_) {
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bool success = marking_deque_memory_->Uncommit(
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reinterpret_cast<Address>(marking_deque_memory_->address()),
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marking_deque_memory_->size());
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CHECK(success);
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marking_deque_memory_committed_ = false;
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}
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}
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void IncrementalMarking::Start() {
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if (FLAG_trace_incremental_marking) {
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PrintF("[IncrementalMarking] Start\n");
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}
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ASSERT(FLAG_incremental_marking);
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ASSERT(state_ == STOPPED);
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ResetStepCounters();
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if (heap_->old_pointer_space()->IsSweepingComplete() &&
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heap_->old_data_space()->IsSweepingComplete()) {
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StartMarking(ALLOW_COMPACTION);
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} else {
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if (FLAG_trace_incremental_marking) {
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PrintF("[IncrementalMarking] Start sweeping.\n");
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}
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state_ = SWEEPING;
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}
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heap_->new_space()->LowerInlineAllocationLimit(kAllocatedThreshold);
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}
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static void MarkObjectGreyDoNotEnqueue(Object* obj) {
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if (obj->IsHeapObject()) {
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HeapObject* heap_obj = HeapObject::cast(obj);
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MarkBit mark_bit = Marking::MarkBitFrom(HeapObject::cast(obj));
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if (Marking::IsBlack(mark_bit)) {
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MemoryChunk::IncrementLiveBytesFromGC(heap_obj->address(),
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-heap_obj->Size());
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}
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Marking::AnyToGrey(mark_bit);
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}
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}
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void IncrementalMarking::StartMarking(CompactionFlag flag) {
|
|
if (FLAG_trace_incremental_marking) {
|
|
PrintF("[IncrementalMarking] Start marking\n");
|
|
}
|
|
|
|
is_compacting_ = !FLAG_never_compact && (flag == ALLOW_COMPACTION) &&
|
|
heap_->mark_compact_collector()->StartCompaction(
|
|
MarkCompactCollector::INCREMENTAL_COMPACTION);
|
|
|
|
state_ = MARKING;
|
|
|
|
RecordWriteStub::Mode mode = is_compacting_ ?
|
|
RecordWriteStub::INCREMENTAL_COMPACTION : RecordWriteStub::INCREMENTAL;
|
|
|
|
PatchIncrementalMarkingRecordWriteStubs(heap_, mode);
|
|
|
|
EnsureMarkingDequeIsCommitted();
|
|
|
|
// Initialize marking stack.
|
|
Address addr = static_cast<Address>(marking_deque_memory_->address());
|
|
size_t size = marking_deque_memory_->size();
|
|
if (FLAG_force_marking_deque_overflows) size = 64 * kPointerSize;
|
|
marking_deque_.Initialize(addr, addr + size);
|
|
|
|
ActivateIncrementalWriteBarrier();
|
|
|
|
#ifdef DEBUG
|
|
// Marking bits are cleared by the sweeper.
|
|
if (FLAG_verify_heap) {
|
|
heap_->mark_compact_collector()->VerifyMarkbitsAreClean();
|
|
}
|
|
#endif
|
|
|
|
heap_->CompletelyClearInstanceofCache();
|
|
heap_->isolate()->compilation_cache()->MarkCompactPrologue();
|
|
|
|
if (FLAG_cleanup_code_caches_at_gc) {
|
|
// We will mark cache black with a separate pass
|
|
// when we finish marking.
|
|
MarkObjectGreyDoNotEnqueue(heap_->polymorphic_code_cache());
|
|
}
|
|
|
|
// Mark strong roots grey.
|
|
IncrementalMarkingRootMarkingVisitor visitor(heap_, this);
|
|
heap_->IterateStrongRoots(&visitor, VISIT_ONLY_STRONG);
|
|
|
|
// Ready to start incremental marking.
|
|
if (FLAG_trace_incremental_marking) {
|
|
PrintF("[IncrementalMarking] Running\n");
|
|
}
|
|
}
|
|
|
|
|
|
void IncrementalMarking::PrepareForScavenge() {
|
|
if (!IsMarking()) return;
|
|
NewSpacePageIterator it(heap_->new_space()->FromSpaceStart(),
|
|
heap_->new_space()->FromSpaceEnd());
|
|
while (it.has_next()) {
|
|
Bitmap::Clear(it.next());
|
|
}
|
|
}
|
|
|
|
|
|
void IncrementalMarking::UpdateMarkingDequeAfterScavenge() {
|
|
if (!IsMarking()) return;
|
|
|
|
int current = marking_deque_.bottom();
|
|
int mask = marking_deque_.mask();
|
|
int limit = marking_deque_.top();
|
|
HeapObject** array = marking_deque_.array();
|
|
int new_top = current;
|
|
|
|
Map* filler_map = heap_->one_pointer_filler_map();
|
|
|
|
while (current != limit) {
|
|
HeapObject* obj = array[current];
|
|
ASSERT(obj->IsHeapObject());
|
|
current = ((current + 1) & mask);
|
|
if (heap_->InNewSpace(obj)) {
|
|
MapWord map_word = obj->map_word();
|
|
if (map_word.IsForwardingAddress()) {
|
|
HeapObject* dest = map_word.ToForwardingAddress();
|
|
array[new_top] = dest;
|
|
new_top = ((new_top + 1) & mask);
|
|
ASSERT(new_top != marking_deque_.bottom());
|
|
#ifdef DEBUG
|
|
MarkBit mark_bit = Marking::MarkBitFrom(obj);
|
|
ASSERT(Marking::IsGrey(mark_bit) ||
|
|
(obj->IsFiller() && Marking::IsWhite(mark_bit)));
|
|
#endif
|
|
}
|
|
} else if (obj->map() != filler_map) {
|
|
// Skip one word filler objects that appear on the
|
|
// stack when we perform in place array shift.
|
|
array[new_top] = obj;
|
|
new_top = ((new_top + 1) & mask);
|
|
ASSERT(new_top != marking_deque_.bottom());
|
|
#ifdef DEBUG
|
|
MarkBit mark_bit = Marking::MarkBitFrom(obj);
|
|
ASSERT(Marking::IsGrey(mark_bit) ||
|
|
(obj->IsFiller() && Marking::IsWhite(mark_bit)));
|
|
#endif
|
|
}
|
|
}
|
|
marking_deque_.set_top(new_top);
|
|
|
|
steps_took_since_last_gc_ = 0;
|
|
steps_count_since_last_gc_ = 0;
|
|
longest_step_ = 0.0;
|
|
}
|
|
|
|
|
|
void IncrementalMarking::VisitGlobalContext(Context* ctx, ObjectVisitor* v) {
|
|
v->VisitPointers(
|
|
HeapObject::RawField(
|
|
ctx, Context::MarkCompactBodyDescriptor::kStartOffset),
|
|
HeapObject::RawField(
|
|
ctx, Context::MarkCompactBodyDescriptor::kEndOffset));
|
|
|
|
MarkCompactCollector* collector = heap_->mark_compact_collector();
|
|
for (int idx = Context::FIRST_WEAK_SLOT;
|
|
idx < Context::GLOBAL_CONTEXT_SLOTS;
|
|
++idx) {
|
|
Object** slot =
|
|
HeapObject::RawField(ctx, FixedArray::OffsetOfElementAt(idx));
|
|
collector->RecordSlot(slot, slot, *slot);
|
|
}
|
|
}
|
|
|
|
|
|
void IncrementalMarking::Hurry() {
|
|
if (state() == MARKING) {
|
|
double start = 0.0;
|
|
if (FLAG_trace_incremental_marking) {
|
|
PrintF("[IncrementalMarking] Hurry\n");
|
|
start = OS::TimeCurrentMillis();
|
|
}
|
|
// TODO(gc) hurry can mark objects it encounters black as mutator
|
|
// was stopped.
|
|
Map* filler_map = heap_->one_pointer_filler_map();
|
|
Map* global_context_map = heap_->global_context_map();
|
|
IncrementalMarkingMarkingVisitor marking_visitor(heap_, this);
|
|
while (!marking_deque_.IsEmpty()) {
|
|
HeapObject* obj = marking_deque_.Pop();
|
|
|
|
// Explicitly skip one word fillers. Incremental markbit patterns are
|
|
// correct only for objects that occupy at least two words.
|
|
Map* map = obj->map();
|
|
if (map == filler_map) {
|
|
continue;
|
|
} else if (map == global_context_map) {
|
|
// Global contexts have weak fields.
|
|
VisitGlobalContext(Context::cast(obj), &marking_visitor);
|
|
} else {
|
|
obj->Iterate(&marking_visitor);
|
|
}
|
|
|
|
MarkBit mark_bit = Marking::MarkBitFrom(obj);
|
|
ASSERT(!Marking::IsBlack(mark_bit));
|
|
Marking::MarkBlack(mark_bit);
|
|
MemoryChunk::IncrementLiveBytesFromGC(obj->address(), obj->Size());
|
|
}
|
|
state_ = COMPLETE;
|
|
if (FLAG_trace_incremental_marking) {
|
|
double end = OS::TimeCurrentMillis();
|
|
PrintF("[IncrementalMarking] Complete (hurry), spent %d ms.\n",
|
|
static_cast<int>(end - start));
|
|
}
|
|
}
|
|
|
|
if (FLAG_cleanup_code_caches_at_gc) {
|
|
PolymorphicCodeCache* poly_cache = heap_->polymorphic_code_cache();
|
|
Marking::GreyToBlack(Marking::MarkBitFrom(poly_cache));
|
|
MemoryChunk::IncrementLiveBytesFromGC(poly_cache->address(),
|
|
PolymorphicCodeCache::kSize);
|
|
}
|
|
|
|
Object* context = heap_->global_contexts_list();
|
|
while (!context->IsUndefined()) {
|
|
// GC can happen when the context is not fully initialized,
|
|
// so the cache can be undefined.
|
|
HeapObject* cache = HeapObject::cast(
|
|
Context::cast(context)->get(Context::NORMALIZED_MAP_CACHE_INDEX));
|
|
if (!cache->IsUndefined()) {
|
|
MarkBit mark_bit = Marking::MarkBitFrom(cache);
|
|
if (Marking::IsGrey(mark_bit)) {
|
|
Marking::GreyToBlack(mark_bit);
|
|
MemoryChunk::IncrementLiveBytesFromGC(cache->address(), cache->Size());
|
|
}
|
|
}
|
|
context = Context::cast(context)->get(Context::NEXT_CONTEXT_LINK);
|
|
}
|
|
}
|
|
|
|
|
|
void IncrementalMarking::Abort() {
|
|
if (IsStopped()) return;
|
|
if (FLAG_trace_incremental_marking) {
|
|
PrintF("[IncrementalMarking] Aborting.\n");
|
|
}
|
|
heap_->new_space()->LowerInlineAllocationLimit(0);
|
|
IncrementalMarking::set_should_hurry(false);
|
|
ResetStepCounters();
|
|
if (IsMarking()) {
|
|
PatchIncrementalMarkingRecordWriteStubs(heap_,
|
|
RecordWriteStub::STORE_BUFFER_ONLY);
|
|
DeactivateIncrementalWriteBarrier();
|
|
|
|
if (is_compacting_) {
|
|
LargeObjectIterator it(heap_->lo_space());
|
|
for (HeapObject* obj = it.Next(); obj != NULL; obj = it.Next()) {
|
|
Page* p = Page::FromAddress(obj->address());
|
|
if (p->IsFlagSet(Page::RESCAN_ON_EVACUATION)) {
|
|
p->ClearFlag(Page::RESCAN_ON_EVACUATION);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
heap_->isolate()->stack_guard()->Continue(GC_REQUEST);
|
|
state_ = STOPPED;
|
|
is_compacting_ = false;
|
|
}
|
|
|
|
|
|
void IncrementalMarking::Finalize() {
|
|
Hurry();
|
|
state_ = STOPPED;
|
|
is_compacting_ = false;
|
|
heap_->new_space()->LowerInlineAllocationLimit(0);
|
|
IncrementalMarking::set_should_hurry(false);
|
|
ResetStepCounters();
|
|
PatchIncrementalMarkingRecordWriteStubs(heap_,
|
|
RecordWriteStub::STORE_BUFFER_ONLY);
|
|
DeactivateIncrementalWriteBarrier();
|
|
ASSERT(marking_deque_.IsEmpty());
|
|
heap_->isolate()->stack_guard()->Continue(GC_REQUEST);
|
|
}
|
|
|
|
|
|
void IncrementalMarking::MarkingComplete() {
|
|
state_ = COMPLETE;
|
|
// We will set the stack guard to request a GC now. This will mean the rest
|
|
// of the GC gets performed as soon as possible (we can't do a GC here in a
|
|
// record-write context). If a few things get allocated between now and then
|
|
// that shouldn't make us do a scavenge and keep being incremental, so we set
|
|
// the should-hurry flag to indicate that there can't be much work left to do.
|
|
set_should_hurry(true);
|
|
if (FLAG_trace_incremental_marking) {
|
|
PrintF("[IncrementalMarking] Complete (normal).\n");
|
|
}
|
|
if (!heap_->idle_notification_will_schedule_next_gc()) {
|
|
heap_->isolate()->stack_guard()->RequestGC();
|
|
}
|
|
}
|
|
|
|
|
|
void IncrementalMarking::Step(intptr_t allocated_bytes) {
|
|
if (heap_->gc_state() != Heap::NOT_IN_GC ||
|
|
!FLAG_incremental_marking ||
|
|
!FLAG_incremental_marking_steps ||
|
|
(state_ != SWEEPING && state_ != MARKING)) {
|
|
return;
|
|
}
|
|
|
|
allocated_ += allocated_bytes;
|
|
|
|
if (allocated_ < kAllocatedThreshold) return;
|
|
|
|
if (state_ == MARKING && no_marking_scope_depth_ > 0) return;
|
|
|
|
intptr_t bytes_to_process = allocated_ * allocation_marking_factor_;
|
|
bytes_scanned_ += bytes_to_process;
|
|
|
|
double start = 0;
|
|
|
|
if (FLAG_trace_incremental_marking || FLAG_trace_gc) {
|
|
start = OS::TimeCurrentMillis();
|
|
}
|
|
|
|
if (state_ == SWEEPING) {
|
|
if (heap_->AdvanceSweepers(static_cast<int>(bytes_to_process))) {
|
|
bytes_scanned_ = 0;
|
|
StartMarking(PREVENT_COMPACTION);
|
|
}
|
|
} else if (state_ == MARKING) {
|
|
Map* filler_map = heap_->one_pointer_filler_map();
|
|
Map* global_context_map = heap_->global_context_map();
|
|
IncrementalMarkingMarkingVisitor marking_visitor(heap_, this);
|
|
while (!marking_deque_.IsEmpty() && bytes_to_process > 0) {
|
|
HeapObject* obj = marking_deque_.Pop();
|
|
|
|
// Explicitly skip one word fillers. Incremental markbit patterns are
|
|
// correct only for objects that occupy at least two words.
|
|
Map* map = obj->map();
|
|
if (map == filler_map) continue;
|
|
|
|
int size = obj->SizeFromMap(map);
|
|
bytes_to_process -= size;
|
|
MarkBit map_mark_bit = Marking::MarkBitFrom(map);
|
|
if (Marking::IsWhite(map_mark_bit)) {
|
|
WhiteToGreyAndPush(map, map_mark_bit);
|
|
}
|
|
|
|
// TODO(gc) switch to static visitor instead of normal visitor.
|
|
if (map == global_context_map) {
|
|
// Global contexts have weak fields.
|
|
Context* ctx = Context::cast(obj);
|
|
|
|
// We will mark cache black with a separate pass
|
|
// when we finish marking.
|
|
MarkObjectGreyDoNotEnqueue(ctx->normalized_map_cache());
|
|
|
|
VisitGlobalContext(ctx, &marking_visitor);
|
|
} else {
|
|
obj->IterateBody(map->instance_type(), size, &marking_visitor);
|
|
}
|
|
|
|
MarkBit obj_mark_bit = Marking::MarkBitFrom(obj);
|
|
SLOW_ASSERT(Marking::IsGrey(obj_mark_bit) ||
|
|
(obj->IsFiller() && Marking::IsWhite(obj_mark_bit)));
|
|
Marking::MarkBlack(obj_mark_bit);
|
|
MemoryChunk::IncrementLiveBytesFromGC(obj->address(), size);
|
|
}
|
|
if (marking_deque_.IsEmpty()) MarkingComplete();
|
|
}
|
|
|
|
allocated_ = 0;
|
|
|
|
steps_count_++;
|
|
steps_count_since_last_gc_++;
|
|
|
|
bool speed_up = false;
|
|
|
|
if ((steps_count_ % kAllocationMarkingFactorSpeedupInterval) == 0) {
|
|
if (FLAG_trace_gc) {
|
|
PrintF("Speed up marking after %d steps\n",
|
|
static_cast<int>(kAllocationMarkingFactorSpeedupInterval));
|
|
}
|
|
speed_up = true;
|
|
}
|
|
|
|
bool space_left_is_very_small =
|
|
(old_generation_space_available_at_start_of_incremental_ < 10 * MB);
|
|
|
|
bool only_1_nth_of_space_that_was_available_still_left =
|
|
(SpaceLeftInOldSpace() * (allocation_marking_factor_ + 1) <
|
|
old_generation_space_available_at_start_of_incremental_);
|
|
|
|
if (space_left_is_very_small ||
|
|
only_1_nth_of_space_that_was_available_still_left) {
|
|
if (FLAG_trace_gc) PrintF("Speed up marking because of low space left\n");
|
|
speed_up = true;
|
|
}
|
|
|
|
bool size_of_old_space_multiplied_by_n_during_marking =
|
|
(heap_->PromotedTotalSize() >
|
|
(allocation_marking_factor_ + 1) *
|
|
old_generation_space_used_at_start_of_incremental_);
|
|
if (size_of_old_space_multiplied_by_n_during_marking) {
|
|
speed_up = true;
|
|
if (FLAG_trace_gc) {
|
|
PrintF("Speed up marking because of heap size increase\n");
|
|
}
|
|
}
|
|
|
|
int64_t promoted_during_marking = heap_->PromotedTotalSize()
|
|
- old_generation_space_used_at_start_of_incremental_;
|
|
intptr_t delay = allocation_marking_factor_ * MB;
|
|
intptr_t scavenge_slack = heap_->MaxSemiSpaceSize();
|
|
|
|
// We try to scan at at least twice the speed that we are allocating.
|
|
if (promoted_during_marking > bytes_scanned_ / 2 + scavenge_slack + delay) {
|
|
if (FLAG_trace_gc) {
|
|
PrintF("Speed up marking because marker was not keeping up\n");
|
|
}
|
|
speed_up = true;
|
|
}
|
|
|
|
if (speed_up) {
|
|
if (state_ != MARKING) {
|
|
if (FLAG_trace_gc) {
|
|
PrintF("Postponing speeding up marking until marking starts\n");
|
|
}
|
|
} else {
|
|
allocation_marking_factor_ += kAllocationMarkingFactorSpeedup;
|
|
allocation_marking_factor_ = static_cast<int>(
|
|
Min(kMaxAllocationMarkingFactor,
|
|
static_cast<intptr_t>(allocation_marking_factor_ * 1.3)));
|
|
if (FLAG_trace_gc) {
|
|
PrintF("Marking speed increased to %d\n", allocation_marking_factor_);
|
|
}
|
|
}
|
|
}
|
|
|
|
if (FLAG_trace_incremental_marking || FLAG_trace_gc) {
|
|
double end = OS::TimeCurrentMillis();
|
|
double delta = (end - start);
|
|
longest_step_ = Max(longest_step_, delta);
|
|
steps_took_ += delta;
|
|
steps_took_since_last_gc_ += delta;
|
|
}
|
|
}
|
|
|
|
|
|
void IncrementalMarking::ResetStepCounters() {
|
|
steps_count_ = 0;
|
|
steps_took_ = 0;
|
|
longest_step_ = 0.0;
|
|
old_generation_space_available_at_start_of_incremental_ =
|
|
SpaceLeftInOldSpace();
|
|
old_generation_space_used_at_start_of_incremental_ =
|
|
heap_->PromotedTotalSize();
|
|
steps_count_since_last_gc_ = 0;
|
|
steps_took_since_last_gc_ = 0;
|
|
bytes_rescanned_ = 0;
|
|
allocation_marking_factor_ = kInitialAllocationMarkingFactor;
|
|
bytes_scanned_ = 0;
|
|
}
|
|
|
|
|
|
int64_t IncrementalMarking::SpaceLeftInOldSpace() {
|
|
return heap_->MaxOldGenerationSize() - heap_->PromotedSpaceSize();
|
|
}
|
|
|
|
} } // namespace v8::internal
|