| Index: src/mark-compact.cc
|
| diff --git a/src/mark-compact.cc b/src/mark-compact.cc
|
| deleted file mode 100644
|
| index a2d9f02e0fbeb04f263435af9104a67a354b9f21..0000000000000000000000000000000000000000
|
| --- a/src/mark-compact.cc
|
| +++ /dev/null
|
| @@ -1,4630 +0,0 @@
|
| -// Copyright 2012 the V8 project authors. All rights reserved.
|
| -// Use of this source code is governed by a BSD-style license that can be
|
| -// found in the LICENSE file.
|
| -
|
| -#include "src/v8.h"
|
| -
|
| -#include "src/base/atomicops.h"
|
| -#include "src/code-stubs.h"
|
| -#include "src/compilation-cache.h"
|
| -#include "src/cpu-profiler.h"
|
| -#include "src/deoptimizer.h"
|
| -#include "src/execution.h"
|
| -#include "src/gdb-jit.h"
|
| -#include "src/global-handles.h"
|
| -#include "src/heap-profiler.h"
|
| -#include "src/ic-inl.h"
|
| -#include "src/incremental-marking.h"
|
| -#include "src/mark-compact.h"
|
| -#include "src/objects-visiting.h"
|
| -#include "src/objects-visiting-inl.h"
|
| -#include "src/spaces-inl.h"
|
| -#include "src/stub-cache.h"
|
| -#include "src/sweeper-thread.h"
|
| -
|
| -namespace v8 {
|
| -namespace internal {
|
| -
|
| -
|
| -const char* Marking::kWhiteBitPattern = "00";
|
| -const char* Marking::kBlackBitPattern = "10";
|
| -const char* Marking::kGreyBitPattern = "11";
|
| -const char* Marking::kImpossibleBitPattern = "01";
|
| -
|
| -
|
| -// -------------------------------------------------------------------------
|
| -// MarkCompactCollector
|
| -
|
| -MarkCompactCollector::MarkCompactCollector(Heap* heap) : // NOLINT
|
| -#ifdef DEBUG
|
| - state_(IDLE),
|
| -#endif
|
| - sweep_precisely_(false),
|
| - reduce_memory_footprint_(false),
|
| - abort_incremental_marking_(false),
|
| - marking_parity_(ODD_MARKING_PARITY),
|
| - compacting_(false),
|
| - was_marked_incrementally_(false),
|
| - sweeping_in_progress_(false),
|
| - pending_sweeper_jobs_semaphore_(0),
|
| - sequential_sweeping_(false),
|
| - migration_slots_buffer_(NULL),
|
| - heap_(heap),
|
| - code_flusher_(NULL),
|
| - have_code_to_deoptimize_(false) { }
|
| -
|
| -#ifdef VERIFY_HEAP
|
| -class VerifyMarkingVisitor: public ObjectVisitor {
|
| - public:
|
| - explicit VerifyMarkingVisitor(Heap* heap) : heap_(heap) {}
|
| -
|
| - void VisitPointers(Object** start, Object** end) {
|
| - for (Object** current = start; current < end; current++) {
|
| - if ((*current)->IsHeapObject()) {
|
| - HeapObject* object = HeapObject::cast(*current);
|
| - CHECK(heap_->mark_compact_collector()->IsMarked(object));
|
| - }
|
| - }
|
| - }
|
| -
|
| - void VisitEmbeddedPointer(RelocInfo* rinfo) {
|
| - DCHECK(rinfo->rmode() == RelocInfo::EMBEDDED_OBJECT);
|
| - if (!rinfo->host()->IsWeakObject(rinfo->target_object())) {
|
| - Object* p = rinfo->target_object();
|
| - VisitPointer(&p);
|
| - }
|
| - }
|
| -
|
| - void VisitCell(RelocInfo* rinfo) {
|
| - Code* code = rinfo->host();
|
| - DCHECK(rinfo->rmode() == RelocInfo::CELL);
|
| - if (!code->IsWeakObject(rinfo->target_cell())) {
|
| - ObjectVisitor::VisitCell(rinfo);
|
| - }
|
| - }
|
| -
|
| - private:
|
| - Heap* heap_;
|
| -};
|
| -
|
| -
|
| -static void VerifyMarking(Heap* heap, Address bottom, Address top) {
|
| - VerifyMarkingVisitor visitor(heap);
|
| - HeapObject* object;
|
| - Address next_object_must_be_here_or_later = bottom;
|
| -
|
| - for (Address current = bottom;
|
| - current < top;
|
| - current += kPointerSize) {
|
| - object = HeapObject::FromAddress(current);
|
| - if (MarkCompactCollector::IsMarked(object)) {
|
| - CHECK(current >= next_object_must_be_here_or_later);
|
| - object->Iterate(&visitor);
|
| - next_object_must_be_here_or_later = current + object->Size();
|
| - }
|
| - }
|
| -}
|
| -
|
| -
|
| -static void VerifyMarking(NewSpace* space) {
|
| - Address end = space->top();
|
| - NewSpacePageIterator it(space->bottom(), end);
|
| - // The bottom position is at the start of its page. Allows us to use
|
| - // page->area_start() as start of range on all pages.
|
| - CHECK_EQ(space->bottom(),
|
| - NewSpacePage::FromAddress(space->bottom())->area_start());
|
| - while (it.has_next()) {
|
| - NewSpacePage* page = it.next();
|
| - Address limit = it.has_next() ? page->area_end() : end;
|
| - CHECK(limit == end || !page->Contains(end));
|
| - VerifyMarking(space->heap(), page->area_start(), limit);
|
| - }
|
| -}
|
| -
|
| -
|
| -static void VerifyMarking(PagedSpace* space) {
|
| - PageIterator it(space);
|
| -
|
| - while (it.has_next()) {
|
| - Page* p = it.next();
|
| - VerifyMarking(space->heap(), p->area_start(), p->area_end());
|
| - }
|
| -}
|
| -
|
| -
|
| -static void VerifyMarking(Heap* heap) {
|
| - VerifyMarking(heap->old_pointer_space());
|
| - VerifyMarking(heap->old_data_space());
|
| - VerifyMarking(heap->code_space());
|
| - VerifyMarking(heap->cell_space());
|
| - VerifyMarking(heap->property_cell_space());
|
| - VerifyMarking(heap->map_space());
|
| - VerifyMarking(heap->new_space());
|
| -
|
| - VerifyMarkingVisitor visitor(heap);
|
| -
|
| - LargeObjectIterator it(heap->lo_space());
|
| - for (HeapObject* obj = it.Next(); obj != NULL; obj = it.Next()) {
|
| - if (MarkCompactCollector::IsMarked(obj)) {
|
| - obj->Iterate(&visitor);
|
| - }
|
| - }
|
| -
|
| - heap->IterateStrongRoots(&visitor, VISIT_ONLY_STRONG);
|
| -}
|
| -
|
| -
|
| -class VerifyEvacuationVisitor: public ObjectVisitor {
|
| - public:
|
| - void VisitPointers(Object** start, Object** end) {
|
| - for (Object** current = start; current < end; current++) {
|
| - if ((*current)->IsHeapObject()) {
|
| - HeapObject* object = HeapObject::cast(*current);
|
| - CHECK(!MarkCompactCollector::IsOnEvacuationCandidate(object));
|
| - }
|
| - }
|
| - }
|
| -};
|
| -
|
| -
|
| -static void VerifyEvacuation(Page* page) {
|
| - VerifyEvacuationVisitor visitor;
|
| - HeapObjectIterator iterator(page, NULL);
|
| - for (HeapObject* heap_object = iterator.Next(); heap_object != NULL;
|
| - heap_object = iterator.Next()) {
|
| - // We skip free space objects.
|
| - if (!heap_object->IsFiller()) {
|
| - heap_object->Iterate(&visitor);
|
| - }
|
| - }
|
| -}
|
| -
|
| -
|
| -static void VerifyEvacuation(NewSpace* space) {
|
| - NewSpacePageIterator it(space->bottom(), space->top());
|
| - VerifyEvacuationVisitor visitor;
|
| -
|
| - while (it.has_next()) {
|
| - NewSpacePage* page = it.next();
|
| - Address current = page->area_start();
|
| - Address limit = it.has_next() ? page->area_end() : space->top();
|
| - CHECK(limit == space->top() || !page->Contains(space->top()));
|
| - while (current < limit) {
|
| - HeapObject* object = HeapObject::FromAddress(current);
|
| - object->Iterate(&visitor);
|
| - current += object->Size();
|
| - }
|
| - }
|
| -}
|
| -
|
| -
|
| -static void VerifyEvacuation(Heap* heap, PagedSpace* space) {
|
| - if (!space->swept_precisely()) return;
|
| - if (FLAG_use_allocation_folding &&
|
| - (space == heap->old_pointer_space() || space == heap->old_data_space())) {
|
| - return;
|
| - }
|
| - PageIterator it(space);
|
| -
|
| - while (it.has_next()) {
|
| - Page* p = it.next();
|
| - if (p->IsEvacuationCandidate()) continue;
|
| - VerifyEvacuation(p);
|
| - }
|
| -}
|
| -
|
| -
|
| -static void VerifyEvacuation(Heap* heap) {
|
| - VerifyEvacuation(heap, heap->old_pointer_space());
|
| - VerifyEvacuation(heap, heap->old_data_space());
|
| - VerifyEvacuation(heap, heap->code_space());
|
| - VerifyEvacuation(heap, heap->cell_space());
|
| - VerifyEvacuation(heap, heap->property_cell_space());
|
| - VerifyEvacuation(heap, heap->map_space());
|
| - VerifyEvacuation(heap->new_space());
|
| -
|
| - VerifyEvacuationVisitor visitor;
|
| - heap->IterateStrongRoots(&visitor, VISIT_ALL);
|
| -}
|
| -#endif // VERIFY_HEAP
|
| -
|
| -
|
| -#ifdef DEBUG
|
| -class VerifyNativeContextSeparationVisitor: public ObjectVisitor {
|
| - public:
|
| - VerifyNativeContextSeparationVisitor() : current_native_context_(NULL) {}
|
| -
|
| - void VisitPointers(Object** start, Object** end) {
|
| - for (Object** current = start; current < end; current++) {
|
| - if ((*current)->IsHeapObject()) {
|
| - HeapObject* object = HeapObject::cast(*current);
|
| - if (object->IsString()) continue;
|
| - switch (object->map()->instance_type()) {
|
| - case JS_FUNCTION_TYPE:
|
| - CheckContext(JSFunction::cast(object)->context());
|
| - break;
|
| - case JS_GLOBAL_PROXY_TYPE:
|
| - CheckContext(JSGlobalProxy::cast(object)->native_context());
|
| - break;
|
| - case JS_GLOBAL_OBJECT_TYPE:
|
| - case JS_BUILTINS_OBJECT_TYPE:
|
| - CheckContext(GlobalObject::cast(object)->native_context());
|
| - break;
|
| - case JS_ARRAY_TYPE:
|
| - case JS_DATE_TYPE:
|
| - case JS_OBJECT_TYPE:
|
| - case JS_REGEXP_TYPE:
|
| - VisitPointer(HeapObject::RawField(object, JSObject::kMapOffset));
|
| - break;
|
| - case MAP_TYPE:
|
| - VisitPointer(HeapObject::RawField(object, Map::kPrototypeOffset));
|
| - VisitPointer(HeapObject::RawField(object, Map::kConstructorOffset));
|
| - break;
|
| - case FIXED_ARRAY_TYPE:
|
| - if (object->IsContext()) {
|
| - CheckContext(object);
|
| - } else {
|
| - FixedArray* array = FixedArray::cast(object);
|
| - int length = array->length();
|
| - // Set array length to zero to prevent cycles while iterating
|
| - // over array bodies, this is easier than intrusive marking.
|
| - array->set_length(0);
|
| - array->IterateBody(
|
| - FIXED_ARRAY_TYPE, FixedArray::SizeFor(length), this);
|
| - array->set_length(length);
|
| - }
|
| - break;
|
| - case CELL_TYPE:
|
| - case JS_PROXY_TYPE:
|
| - case JS_VALUE_TYPE:
|
| - case TYPE_FEEDBACK_INFO_TYPE:
|
| - object->Iterate(this);
|
| - break;
|
| - case DECLARED_ACCESSOR_INFO_TYPE:
|
| - case EXECUTABLE_ACCESSOR_INFO_TYPE:
|
| - case BYTE_ARRAY_TYPE:
|
| - case CALL_HANDLER_INFO_TYPE:
|
| - case CODE_TYPE:
|
| - case FIXED_DOUBLE_ARRAY_TYPE:
|
| - case HEAP_NUMBER_TYPE:
|
| - case MUTABLE_HEAP_NUMBER_TYPE:
|
| - case INTERCEPTOR_INFO_TYPE:
|
| - case ODDBALL_TYPE:
|
| - case SCRIPT_TYPE:
|
| - case SHARED_FUNCTION_INFO_TYPE:
|
| - break;
|
| - default:
|
| - UNREACHABLE();
|
| - }
|
| - }
|
| - }
|
| - }
|
| -
|
| - private:
|
| - void CheckContext(Object* context) {
|
| - if (!context->IsContext()) return;
|
| - Context* native_context = Context::cast(context)->native_context();
|
| - if (current_native_context_ == NULL) {
|
| - current_native_context_ = native_context;
|
| - } else {
|
| - CHECK_EQ(current_native_context_, native_context);
|
| - }
|
| - }
|
| -
|
| - Context* current_native_context_;
|
| -};
|
| -
|
| -
|
| -static void VerifyNativeContextSeparation(Heap* heap) {
|
| - HeapObjectIterator it(heap->code_space());
|
| -
|
| - for (Object* object = it.Next(); object != NULL; object = it.Next()) {
|
| - VerifyNativeContextSeparationVisitor visitor;
|
| - Code::cast(object)->CodeIterateBody(&visitor);
|
| - }
|
| -}
|
| -#endif
|
| -
|
| -
|
| -void MarkCompactCollector::SetUp() {
|
| - free_list_old_data_space_.Reset(new FreeList(heap_->old_data_space()));
|
| - free_list_old_pointer_space_.Reset(new FreeList(heap_->old_pointer_space()));
|
| -}
|
| -
|
| -
|
| -void MarkCompactCollector::TearDown() {
|
| - AbortCompaction();
|
| -}
|
| -
|
| -
|
| -void MarkCompactCollector::AddEvacuationCandidate(Page* p) {
|
| - p->MarkEvacuationCandidate();
|
| - evacuation_candidates_.Add(p);
|
| -}
|
| -
|
| -
|
| -static void TraceFragmentation(PagedSpace* space) {
|
| - int number_of_pages = space->CountTotalPages();
|
| - intptr_t reserved = (number_of_pages * space->AreaSize());
|
| - intptr_t free = reserved - space->SizeOfObjects();
|
| - PrintF("[%s]: %d pages, %d (%.1f%%) free\n",
|
| - AllocationSpaceName(space->identity()),
|
| - number_of_pages,
|
| - static_cast<int>(free),
|
| - static_cast<double>(free) * 100 / reserved);
|
| -}
|
| -
|
| -
|
| -bool MarkCompactCollector::StartCompaction(CompactionMode mode) {
|
| - if (!compacting_) {
|
| - DCHECK(evacuation_candidates_.length() == 0);
|
| -
|
| -#ifdef ENABLE_GDB_JIT_INTERFACE
|
| - // If GDBJIT interface is active disable compaction.
|
| - if (FLAG_gdbjit) return false;
|
| -#endif
|
| -
|
| - CollectEvacuationCandidates(heap()->old_pointer_space());
|
| - CollectEvacuationCandidates(heap()->old_data_space());
|
| -
|
| - if (FLAG_compact_code_space &&
|
| - (mode == NON_INCREMENTAL_COMPACTION ||
|
| - FLAG_incremental_code_compaction)) {
|
| - CollectEvacuationCandidates(heap()->code_space());
|
| - } else if (FLAG_trace_fragmentation) {
|
| - TraceFragmentation(heap()->code_space());
|
| - }
|
| -
|
| - if (FLAG_trace_fragmentation) {
|
| - TraceFragmentation(heap()->map_space());
|
| - TraceFragmentation(heap()->cell_space());
|
| - TraceFragmentation(heap()->property_cell_space());
|
| - }
|
| -
|
| - heap()->old_pointer_space()->EvictEvacuationCandidatesFromFreeLists();
|
| - heap()->old_data_space()->EvictEvacuationCandidatesFromFreeLists();
|
| - heap()->code_space()->EvictEvacuationCandidatesFromFreeLists();
|
| -
|
| - compacting_ = evacuation_candidates_.length() > 0;
|
| - }
|
| -
|
| - return compacting_;
|
| -}
|
| -
|
| -
|
| -void MarkCompactCollector::CollectGarbage() {
|
| - // Make sure that Prepare() has been called. The individual steps below will
|
| - // update the state as they proceed.
|
| - DCHECK(state_ == PREPARE_GC);
|
| -
|
| - MarkLiveObjects();
|
| - DCHECK(heap_->incremental_marking()->IsStopped());
|
| -
|
| - if (FLAG_collect_maps) ClearNonLiveReferences();
|
| -
|
| - ClearWeakCollections();
|
| -
|
| -#ifdef VERIFY_HEAP
|
| - if (FLAG_verify_heap) {
|
| - VerifyMarking(heap_);
|
| - }
|
| -#endif
|
| -
|
| - SweepSpaces();
|
| -
|
| -#ifdef DEBUG
|
| - if (FLAG_verify_native_context_separation) {
|
| - VerifyNativeContextSeparation(heap_);
|
| - }
|
| -#endif
|
| -
|
| -#ifdef VERIFY_HEAP
|
| - if (heap()->weak_embedded_objects_verification_enabled()) {
|
| - VerifyWeakEmbeddedObjectsInCode();
|
| - }
|
| - if (FLAG_collect_maps && FLAG_omit_map_checks_for_leaf_maps) {
|
| - VerifyOmittedMapChecks();
|
| - }
|
| -#endif
|
| -
|
| - Finish();
|
| -
|
| - if (marking_parity_ == EVEN_MARKING_PARITY) {
|
| - marking_parity_ = ODD_MARKING_PARITY;
|
| - } else {
|
| - DCHECK(marking_parity_ == ODD_MARKING_PARITY);
|
| - marking_parity_ = EVEN_MARKING_PARITY;
|
| - }
|
| -}
|
| -
|
| -
|
| -#ifdef VERIFY_HEAP
|
| -void MarkCompactCollector::VerifyMarkbitsAreClean(PagedSpace* space) {
|
| - PageIterator it(space);
|
| -
|
| - while (it.has_next()) {
|
| - Page* p = it.next();
|
| - CHECK(p->markbits()->IsClean());
|
| - CHECK_EQ(0, p->LiveBytes());
|
| - }
|
| -}
|
| -
|
| -
|
| -void MarkCompactCollector::VerifyMarkbitsAreClean(NewSpace* space) {
|
| - NewSpacePageIterator it(space->bottom(), space->top());
|
| -
|
| - while (it.has_next()) {
|
| - NewSpacePage* p = it.next();
|
| - CHECK(p->markbits()->IsClean());
|
| - CHECK_EQ(0, p->LiveBytes());
|
| - }
|
| -}
|
| -
|
| -
|
| -void MarkCompactCollector::VerifyMarkbitsAreClean() {
|
| - VerifyMarkbitsAreClean(heap_->old_pointer_space());
|
| - VerifyMarkbitsAreClean(heap_->old_data_space());
|
| - VerifyMarkbitsAreClean(heap_->code_space());
|
| - VerifyMarkbitsAreClean(heap_->cell_space());
|
| - VerifyMarkbitsAreClean(heap_->property_cell_space());
|
| - VerifyMarkbitsAreClean(heap_->map_space());
|
| - VerifyMarkbitsAreClean(heap_->new_space());
|
| -
|
| - LargeObjectIterator it(heap_->lo_space());
|
| - for (HeapObject* obj = it.Next(); obj != NULL; obj = it.Next()) {
|
| - MarkBit mark_bit = Marking::MarkBitFrom(obj);
|
| - CHECK(Marking::IsWhite(mark_bit));
|
| - CHECK_EQ(0, Page::FromAddress(obj->address())->LiveBytes());
|
| - }
|
| -}
|
| -
|
| -
|
| -void MarkCompactCollector::VerifyWeakEmbeddedObjectsInCode() {
|
| - HeapObjectIterator code_iterator(heap()->code_space());
|
| - for (HeapObject* obj = code_iterator.Next();
|
| - obj != NULL;
|
| - obj = code_iterator.Next()) {
|
| - Code* code = Code::cast(obj);
|
| - if (!code->is_optimized_code() && !code->is_weak_stub()) continue;
|
| - if (WillBeDeoptimized(code)) continue;
|
| - code->VerifyEmbeddedObjectsDependency();
|
| - }
|
| -}
|
| -
|
| -
|
| -void MarkCompactCollector::VerifyOmittedMapChecks() {
|
| - HeapObjectIterator iterator(heap()->map_space());
|
| - for (HeapObject* obj = iterator.Next();
|
| - obj != NULL;
|
| - obj = iterator.Next()) {
|
| - Map* map = Map::cast(obj);
|
| - map->VerifyOmittedMapChecks();
|
| - }
|
| -}
|
| -#endif // VERIFY_HEAP
|
| -
|
| -
|
| -static void ClearMarkbitsInPagedSpace(PagedSpace* space) {
|
| - PageIterator it(space);
|
| -
|
| - while (it.has_next()) {
|
| - Bitmap::Clear(it.next());
|
| - }
|
| -}
|
| -
|
| -
|
| -static void ClearMarkbitsInNewSpace(NewSpace* space) {
|
| - NewSpacePageIterator it(space->ToSpaceStart(), space->ToSpaceEnd());
|
| -
|
| - while (it.has_next()) {
|
| - Bitmap::Clear(it.next());
|
| - }
|
| -}
|
| -
|
| -
|
| -void MarkCompactCollector::ClearMarkbits() {
|
| - ClearMarkbitsInPagedSpace(heap_->code_space());
|
| - ClearMarkbitsInPagedSpace(heap_->map_space());
|
| - ClearMarkbitsInPagedSpace(heap_->old_pointer_space());
|
| - ClearMarkbitsInPagedSpace(heap_->old_data_space());
|
| - ClearMarkbitsInPagedSpace(heap_->cell_space());
|
| - ClearMarkbitsInPagedSpace(heap_->property_cell_space());
|
| - ClearMarkbitsInNewSpace(heap_->new_space());
|
| -
|
| - LargeObjectIterator it(heap_->lo_space());
|
| - for (HeapObject* obj = it.Next(); obj != NULL; obj = it.Next()) {
|
| - MarkBit mark_bit = Marking::MarkBitFrom(obj);
|
| - mark_bit.Clear();
|
| - mark_bit.Next().Clear();
|
| - Page::FromAddress(obj->address())->ResetProgressBar();
|
| - Page::FromAddress(obj->address())->ResetLiveBytes();
|
| - }
|
| -}
|
| -
|
| -
|
| -class MarkCompactCollector::SweeperTask : public v8::Task {
|
| - public:
|
| - SweeperTask(Heap* heap, PagedSpace* space)
|
| - : heap_(heap), space_(space) {}
|
| -
|
| - virtual ~SweeperTask() {}
|
| -
|
| - private:
|
| - // v8::Task overrides.
|
| - virtual void Run() V8_OVERRIDE {
|
| - heap_->mark_compact_collector()->SweepInParallel(space_, 0);
|
| - heap_->mark_compact_collector()->pending_sweeper_jobs_semaphore_.Signal();
|
| - }
|
| -
|
| - Heap* heap_;
|
| - PagedSpace* space_;
|
| -
|
| - DISALLOW_COPY_AND_ASSIGN(SweeperTask);
|
| -};
|
| -
|
| -
|
| -void MarkCompactCollector::StartSweeperThreads() {
|
| - DCHECK(free_list_old_pointer_space_.get()->IsEmpty());
|
| - DCHECK(free_list_old_data_space_.get()->IsEmpty());
|
| - sweeping_in_progress_ = true;
|
| - for (int i = 0; i < isolate()->num_sweeper_threads(); i++) {
|
| - isolate()->sweeper_threads()[i]->StartSweeping();
|
| - }
|
| - if (FLAG_job_based_sweeping) {
|
| - V8::GetCurrentPlatform()->CallOnBackgroundThread(
|
| - new SweeperTask(heap(), heap()->old_data_space()),
|
| - v8::Platform::kShortRunningTask);
|
| - V8::GetCurrentPlatform()->CallOnBackgroundThread(
|
| - new SweeperTask(heap(), heap()->old_pointer_space()),
|
| - v8::Platform::kShortRunningTask);
|
| - }
|
| -}
|
| -
|
| -
|
| -void MarkCompactCollector::EnsureSweepingCompleted() {
|
| - DCHECK(sweeping_in_progress_ == true);
|
| -
|
| - // If sweeping is not completed, we try to complete it here. If we do not
|
| - // have sweeper threads we have to complete since we do not have a good
|
| - // indicator for a swept space in that case.
|
| - if (!AreSweeperThreadsActivated() || !IsSweepingCompleted()) {
|
| - SweepInParallel(heap()->paged_space(OLD_DATA_SPACE), 0);
|
| - SweepInParallel(heap()->paged_space(OLD_POINTER_SPACE), 0);
|
| - }
|
| -
|
| - for (int i = 0; i < isolate()->num_sweeper_threads(); i++) {
|
| - isolate()->sweeper_threads()[i]->WaitForSweeperThread();
|
| - }
|
| - if (FLAG_job_based_sweeping) {
|
| - // Wait twice for both jobs.
|
| - pending_sweeper_jobs_semaphore_.Wait();
|
| - pending_sweeper_jobs_semaphore_.Wait();
|
| - }
|
| - ParallelSweepSpacesComplete();
|
| - sweeping_in_progress_ = false;
|
| - RefillFreeList(heap()->paged_space(OLD_DATA_SPACE));
|
| - RefillFreeList(heap()->paged_space(OLD_POINTER_SPACE));
|
| - heap()->paged_space(OLD_DATA_SPACE)->ResetUnsweptFreeBytes();
|
| - heap()->paged_space(OLD_POINTER_SPACE)->ResetUnsweptFreeBytes();
|
| -
|
| -#ifdef VERIFY_HEAP
|
| - if (FLAG_verify_heap) {
|
| - VerifyEvacuation(heap_);
|
| - }
|
| -#endif
|
| -}
|
| -
|
| -
|
| -bool MarkCompactCollector::IsSweepingCompleted() {
|
| - for (int i = 0; i < isolate()->num_sweeper_threads(); i++) {
|
| - if (!isolate()->sweeper_threads()[i]->SweepingCompleted()) {
|
| - return false;
|
| - }
|
| - }
|
| -
|
| - if (FLAG_job_based_sweeping) {
|
| - if (!pending_sweeper_jobs_semaphore_.WaitFor(
|
| - base::TimeDelta::FromSeconds(0))) {
|
| - return false;
|
| - }
|
| - pending_sweeper_jobs_semaphore_.Signal();
|
| - }
|
| -
|
| - return true;
|
| -}
|
| -
|
| -
|
| -void MarkCompactCollector::RefillFreeList(PagedSpace* space) {
|
| - FreeList* free_list;
|
| -
|
| - if (space == heap()->old_pointer_space()) {
|
| - free_list = free_list_old_pointer_space_.get();
|
| - } else if (space == heap()->old_data_space()) {
|
| - free_list = free_list_old_data_space_.get();
|
| - } else {
|
| - // Any PagedSpace might invoke RefillFreeLists, so we need to make sure
|
| - // to only refill them for old data and pointer spaces.
|
| - return;
|
| - }
|
| -
|
| - intptr_t freed_bytes = space->free_list()->Concatenate(free_list);
|
| - space->AddToAccountingStats(freed_bytes);
|
| - space->DecrementUnsweptFreeBytes(freed_bytes);
|
| -}
|
| -
|
| -
|
| -bool MarkCompactCollector::AreSweeperThreadsActivated() {
|
| - return isolate()->sweeper_threads() != NULL || FLAG_job_based_sweeping;
|
| -}
|
| -
|
| -
|
| -void Marking::TransferMark(Address old_start, Address new_start) {
|
| - // This is only used when resizing an object.
|
| - DCHECK(MemoryChunk::FromAddress(old_start) ==
|
| - MemoryChunk::FromAddress(new_start));
|
| -
|
| - if (!heap_->incremental_marking()->IsMarking()) return;
|
| -
|
| - // If the mark doesn't move, we don't check the color of the object.
|
| - // It doesn't matter whether the object is black, since it hasn't changed
|
| - // size, so the adjustment to the live data count will be zero anyway.
|
| - if (old_start == new_start) return;
|
| -
|
| - MarkBit new_mark_bit = MarkBitFrom(new_start);
|
| - MarkBit old_mark_bit = MarkBitFrom(old_start);
|
| -
|
| -#ifdef DEBUG
|
| - ObjectColor old_color = Color(old_mark_bit);
|
| -#endif
|
| -
|
| - if (Marking::IsBlack(old_mark_bit)) {
|
| - old_mark_bit.Clear();
|
| - DCHECK(IsWhite(old_mark_bit));
|
| - Marking::MarkBlack(new_mark_bit);
|
| - return;
|
| - } else if (Marking::IsGrey(old_mark_bit)) {
|
| - old_mark_bit.Clear();
|
| - old_mark_bit.Next().Clear();
|
| - DCHECK(IsWhite(old_mark_bit));
|
| - heap_->incremental_marking()->WhiteToGreyAndPush(
|
| - HeapObject::FromAddress(new_start), new_mark_bit);
|
| - heap_->incremental_marking()->RestartIfNotMarking();
|
| - }
|
| -
|
| -#ifdef DEBUG
|
| - ObjectColor new_color = Color(new_mark_bit);
|
| - DCHECK(new_color == old_color);
|
| -#endif
|
| -}
|
| -
|
| -
|
| -const char* AllocationSpaceName(AllocationSpace space) {
|
| - switch (space) {
|
| - case NEW_SPACE: return "NEW_SPACE";
|
| - case OLD_POINTER_SPACE: return "OLD_POINTER_SPACE";
|
| - case OLD_DATA_SPACE: return "OLD_DATA_SPACE";
|
| - case CODE_SPACE: return "CODE_SPACE";
|
| - case MAP_SPACE: return "MAP_SPACE";
|
| - case CELL_SPACE: return "CELL_SPACE";
|
| - case PROPERTY_CELL_SPACE:
|
| - return "PROPERTY_CELL_SPACE";
|
| - case LO_SPACE: return "LO_SPACE";
|
| - default:
|
| - UNREACHABLE();
|
| - }
|
| -
|
| - return NULL;
|
| -}
|
| -
|
| -
|
| -// Returns zero for pages that have so little fragmentation that it is not
|
| -// worth defragmenting them. Otherwise a positive integer that gives an
|
| -// estimate of fragmentation on an arbitrary scale.
|
| -static int FreeListFragmentation(PagedSpace* space, Page* p) {
|
| - // If page was not swept then there are no free list items on it.
|
| - if (!p->WasSwept()) {
|
| - if (FLAG_trace_fragmentation) {
|
| - PrintF("%p [%s]: %d bytes live (unswept)\n",
|
| - reinterpret_cast<void*>(p),
|
| - AllocationSpaceName(space->identity()),
|
| - p->LiveBytes());
|
| - }
|
| - return 0;
|
| - }
|
| -
|
| - PagedSpace::SizeStats sizes;
|
| - space->ObtainFreeListStatistics(p, &sizes);
|
| -
|
| - intptr_t ratio;
|
| - intptr_t ratio_threshold;
|
| - intptr_t area_size = space->AreaSize();
|
| - if (space->identity() == CODE_SPACE) {
|
| - ratio = (sizes.medium_size_ * 10 + sizes.large_size_ * 2) * 100 /
|
| - area_size;
|
| - ratio_threshold = 10;
|
| - } else {
|
| - ratio = (sizes.small_size_ * 5 + sizes.medium_size_) * 100 /
|
| - area_size;
|
| - ratio_threshold = 15;
|
| - }
|
| -
|
| - if (FLAG_trace_fragmentation) {
|
| - PrintF("%p [%s]: %d (%.2f%%) %d (%.2f%%) %d (%.2f%%) %d (%.2f%%) %s\n",
|
| - reinterpret_cast<void*>(p),
|
| - AllocationSpaceName(space->identity()),
|
| - static_cast<int>(sizes.small_size_),
|
| - static_cast<double>(sizes.small_size_ * 100) /
|
| - area_size,
|
| - static_cast<int>(sizes.medium_size_),
|
| - static_cast<double>(sizes.medium_size_ * 100) /
|
| - area_size,
|
| - static_cast<int>(sizes.large_size_),
|
| - static_cast<double>(sizes.large_size_ * 100) /
|
| - area_size,
|
| - static_cast<int>(sizes.huge_size_),
|
| - static_cast<double>(sizes.huge_size_ * 100) /
|
| - area_size,
|
| - (ratio > ratio_threshold) ? "[fragmented]" : "");
|
| - }
|
| -
|
| - if (FLAG_always_compact && sizes.Total() != area_size) {
|
| - return 1;
|
| - }
|
| -
|
| - if (ratio <= ratio_threshold) return 0; // Not fragmented.
|
| -
|
| - return static_cast<int>(ratio - ratio_threshold);
|
| -}
|
| -
|
| -
|
| -void MarkCompactCollector::CollectEvacuationCandidates(PagedSpace* space) {
|
| - DCHECK(space->identity() == OLD_POINTER_SPACE ||
|
| - space->identity() == OLD_DATA_SPACE ||
|
| - space->identity() == CODE_SPACE);
|
| -
|
| - static const int kMaxMaxEvacuationCandidates = 1000;
|
| - int number_of_pages = space->CountTotalPages();
|
| - int max_evacuation_candidates =
|
| - static_cast<int>(std::sqrt(number_of_pages / 2.0) + 1);
|
| -
|
| - if (FLAG_stress_compaction || FLAG_always_compact) {
|
| - max_evacuation_candidates = kMaxMaxEvacuationCandidates;
|
| - }
|
| -
|
| - class Candidate {
|
| - public:
|
| - Candidate() : fragmentation_(0), page_(NULL) { }
|
| - Candidate(int f, Page* p) : fragmentation_(f), page_(p) { }
|
| -
|
| - int fragmentation() { return fragmentation_; }
|
| - Page* page() { return page_; }
|
| -
|
| - private:
|
| - int fragmentation_;
|
| - Page* page_;
|
| - };
|
| -
|
| - enum CompactionMode {
|
| - COMPACT_FREE_LISTS,
|
| - REDUCE_MEMORY_FOOTPRINT
|
| - };
|
| -
|
| - CompactionMode mode = COMPACT_FREE_LISTS;
|
| -
|
| - intptr_t reserved = number_of_pages * space->AreaSize();
|
| - intptr_t over_reserved = reserved - space->SizeOfObjects();
|
| - static const intptr_t kFreenessThreshold = 50;
|
| -
|
| - if (reduce_memory_footprint_ && over_reserved >= space->AreaSize()) {
|
| - // If reduction of memory footprint was requested, we are aggressive
|
| - // about choosing pages to free. We expect that half-empty pages
|
| - // are easier to compact so slightly bump the limit.
|
| - mode = REDUCE_MEMORY_FOOTPRINT;
|
| - max_evacuation_candidates += 2;
|
| - }
|
| -
|
| -
|
| - if (over_reserved > reserved / 3 && over_reserved >= 2 * space->AreaSize()) {
|
| - // If over-usage is very high (more than a third of the space), we
|
| - // try to free all mostly empty pages. We expect that almost empty
|
| - // pages are even easier to compact so bump the limit even more.
|
| - mode = REDUCE_MEMORY_FOOTPRINT;
|
| - max_evacuation_candidates *= 2;
|
| - }
|
| -
|
| - if (FLAG_trace_fragmentation && mode == REDUCE_MEMORY_FOOTPRINT) {
|
| - PrintF("Estimated over reserved memory: %.1f / %.1f MB (threshold %d), "
|
| - "evacuation candidate limit: %d\n",
|
| - static_cast<double>(over_reserved) / MB,
|
| - static_cast<double>(reserved) / MB,
|
| - static_cast<int>(kFreenessThreshold),
|
| - max_evacuation_candidates);
|
| - }
|
| -
|
| - intptr_t estimated_release = 0;
|
| -
|
| - Candidate candidates[kMaxMaxEvacuationCandidates];
|
| -
|
| - max_evacuation_candidates =
|
| - Min(kMaxMaxEvacuationCandidates, max_evacuation_candidates);
|
| -
|
| - int count = 0;
|
| - int fragmentation = 0;
|
| - Candidate* least = NULL;
|
| -
|
| - PageIterator it(space);
|
| - if (it.has_next()) it.next(); // Never compact the first page.
|
| -
|
| - while (it.has_next()) {
|
| - Page* p = it.next();
|
| - p->ClearEvacuationCandidate();
|
| -
|
| - if (FLAG_stress_compaction) {
|
| - unsigned int counter = space->heap()->ms_count();
|
| - uintptr_t page_number = reinterpret_cast<uintptr_t>(p) >> kPageSizeBits;
|
| - if ((counter & 1) == (page_number & 1)) fragmentation = 1;
|
| - } else if (mode == REDUCE_MEMORY_FOOTPRINT) {
|
| - // Don't try to release too many pages.
|
| - if (estimated_release >= over_reserved) {
|
| - continue;
|
| - }
|
| -
|
| - intptr_t free_bytes = 0;
|
| -
|
| - if (!p->WasSwept()) {
|
| - free_bytes = (p->area_size() - p->LiveBytes());
|
| - } else {
|
| - PagedSpace::SizeStats sizes;
|
| - space->ObtainFreeListStatistics(p, &sizes);
|
| - free_bytes = sizes.Total();
|
| - }
|
| -
|
| - int free_pct = static_cast<int>(free_bytes * 100) / p->area_size();
|
| -
|
| - if (free_pct >= kFreenessThreshold) {
|
| - estimated_release += free_bytes;
|
| - fragmentation = free_pct;
|
| - } else {
|
| - fragmentation = 0;
|
| - }
|
| -
|
| - if (FLAG_trace_fragmentation) {
|
| - PrintF("%p [%s]: %d (%.2f%%) free %s\n",
|
| - reinterpret_cast<void*>(p),
|
| - AllocationSpaceName(space->identity()),
|
| - static_cast<int>(free_bytes),
|
| - static_cast<double>(free_bytes * 100) / p->area_size(),
|
| - (fragmentation > 0) ? "[fragmented]" : "");
|
| - }
|
| - } else {
|
| - fragmentation = FreeListFragmentation(space, p);
|
| - }
|
| -
|
| - if (fragmentation != 0) {
|
| - if (count < max_evacuation_candidates) {
|
| - candidates[count++] = Candidate(fragmentation, p);
|
| - } else {
|
| - if (least == NULL) {
|
| - for (int i = 0; i < max_evacuation_candidates; i++) {
|
| - if (least == NULL ||
|
| - candidates[i].fragmentation() < least->fragmentation()) {
|
| - least = candidates + i;
|
| - }
|
| - }
|
| - }
|
| - if (least->fragmentation() < fragmentation) {
|
| - *least = Candidate(fragmentation, p);
|
| - least = NULL;
|
| - }
|
| - }
|
| - }
|
| - }
|
| -
|
| - for (int i = 0; i < count; i++) {
|
| - AddEvacuationCandidate(candidates[i].page());
|
| - }
|
| -
|
| - if (count > 0 && FLAG_trace_fragmentation) {
|
| - PrintF("Collected %d evacuation candidates for space %s\n",
|
| - count,
|
| - AllocationSpaceName(space->identity()));
|
| - }
|
| -}
|
| -
|
| -
|
| -void MarkCompactCollector::AbortCompaction() {
|
| - if (compacting_) {
|
| - int npages = evacuation_candidates_.length();
|
| - for (int i = 0; i < npages; i++) {
|
| - Page* p = evacuation_candidates_[i];
|
| - slots_buffer_allocator_.DeallocateChain(p->slots_buffer_address());
|
| - p->ClearEvacuationCandidate();
|
| - p->ClearFlag(MemoryChunk::RESCAN_ON_EVACUATION);
|
| - }
|
| - compacting_ = false;
|
| - evacuation_candidates_.Rewind(0);
|
| - invalidated_code_.Rewind(0);
|
| - }
|
| - DCHECK_EQ(0, evacuation_candidates_.length());
|
| -}
|
| -
|
| -
|
| -void MarkCompactCollector::Prepare() {
|
| - was_marked_incrementally_ = heap()->incremental_marking()->IsMarking();
|
| -
|
| -#ifdef DEBUG
|
| - DCHECK(state_ == IDLE);
|
| - state_ = PREPARE_GC;
|
| -#endif
|
| -
|
| - DCHECK(!FLAG_never_compact || !FLAG_always_compact);
|
| -
|
| - if (sweeping_in_progress()) {
|
| - // Instead of waiting we could also abort the sweeper threads here.
|
| - EnsureSweepingCompleted();
|
| - }
|
| -
|
| - // Clear marking bits if incremental marking is aborted.
|
| - if (was_marked_incrementally_ && abort_incremental_marking_) {
|
| - heap()->incremental_marking()->Abort();
|
| - ClearMarkbits();
|
| - AbortCompaction();
|
| - was_marked_incrementally_ = false;
|
| - }
|
| -
|
| - // Don't start compaction if we are in the middle of incremental
|
| - // marking cycle. We did not collect any slots.
|
| - if (!FLAG_never_compact && !was_marked_incrementally_) {
|
| - StartCompaction(NON_INCREMENTAL_COMPACTION);
|
| - }
|
| -
|
| - PagedSpaces spaces(heap());
|
| - for (PagedSpace* space = spaces.next();
|
| - space != NULL;
|
| - space = spaces.next()) {
|
| - space->PrepareForMarkCompact();
|
| - }
|
| -
|
| -#ifdef VERIFY_HEAP
|
| - if (!was_marked_incrementally_ && FLAG_verify_heap) {
|
| - VerifyMarkbitsAreClean();
|
| - }
|
| -#endif
|
| -}
|
| -
|
| -
|
| -void MarkCompactCollector::Finish() {
|
| -#ifdef DEBUG
|
| - DCHECK(state_ == SWEEP_SPACES || state_ == RELOCATE_OBJECTS);
|
| - state_ = IDLE;
|
| -#endif
|
| - // The stub cache is not traversed during GC; clear the cache to
|
| - // force lazy re-initialization of it. This must be done after the
|
| - // GC, because it relies on the new address of certain old space
|
| - // objects (empty string, illegal builtin).
|
| - isolate()->stub_cache()->Clear();
|
| -
|
| - if (have_code_to_deoptimize_) {
|
| - // Some code objects were marked for deoptimization during the GC.
|
| - Deoptimizer::DeoptimizeMarkedCode(isolate());
|
| - have_code_to_deoptimize_ = false;
|
| - }
|
| -}
|
| -
|
| -
|
| -// -------------------------------------------------------------------------
|
| -// Phase 1: tracing and marking live objects.
|
| -// before: all objects are in normal state.
|
| -// after: a live object's map pointer is marked as '00'.
|
| -
|
| -// Marking all live objects in the heap as part of mark-sweep or mark-compact
|
| -// collection. Before marking, all objects are in their normal state. After
|
| -// marking, live objects' map pointers are marked indicating that the object
|
| -// has been found reachable.
|
| -//
|
| -// The marking algorithm is a (mostly) depth-first (because of possible stack
|
| -// overflow) traversal of the graph of objects reachable from the roots. It
|
| -// uses an explicit stack of pointers rather than recursion. The young
|
| -// generation's inactive ('from') space is used as a marking stack. The
|
| -// objects in the marking stack are the ones that have been reached and marked
|
| -// but their children have not yet been visited.
|
| -//
|
| -// The marking stack can overflow during traversal. In that case, we set an
|
| -// overflow flag. When the overflow flag is set, we continue marking objects
|
| -// reachable from the objects on the marking stack, but no longer push them on
|
| -// the marking stack. Instead, we mark them as both marked and overflowed.
|
| -// When the stack is in the overflowed state, objects marked as overflowed
|
| -// have been reached and marked but their children have not been visited yet.
|
| -// After emptying the marking stack, we clear the overflow flag and traverse
|
| -// the heap looking for objects marked as overflowed, push them on the stack,
|
| -// and continue with marking. This process repeats until all reachable
|
| -// objects have been marked.
|
| -
|
| -void CodeFlusher::ProcessJSFunctionCandidates() {
|
| - Code* lazy_compile =
|
| - isolate_->builtins()->builtin(Builtins::kCompileUnoptimized);
|
| - Object* undefined = isolate_->heap()->undefined_value();
|
| -
|
| - JSFunction* candidate = jsfunction_candidates_head_;
|
| - JSFunction* next_candidate;
|
| - while (candidate != NULL) {
|
| - next_candidate = GetNextCandidate(candidate);
|
| - ClearNextCandidate(candidate, undefined);
|
| -
|
| - SharedFunctionInfo* shared = candidate->shared();
|
| -
|
| - Code* code = shared->code();
|
| - MarkBit code_mark = Marking::MarkBitFrom(code);
|
| - if (!code_mark.Get()) {
|
| - if (FLAG_trace_code_flushing && shared->is_compiled()) {
|
| - PrintF("[code-flushing clears: ");
|
| - shared->ShortPrint();
|
| - PrintF(" - age: %d]\n", code->GetAge());
|
| - }
|
| - shared->set_code(lazy_compile);
|
| - candidate->set_code(lazy_compile);
|
| - } else {
|
| - candidate->set_code(code);
|
| - }
|
| -
|
| - // We are in the middle of a GC cycle so the write barrier in the code
|
| - // setter did not record the slot update and we have to do that manually.
|
| - Address slot = candidate->address() + JSFunction::kCodeEntryOffset;
|
| - Code* target = Code::cast(Code::GetObjectFromEntryAddress(slot));
|
| - isolate_->heap()->mark_compact_collector()->
|
| - RecordCodeEntrySlot(slot, target);
|
| -
|
| - Object** shared_code_slot =
|
| - HeapObject::RawField(shared, SharedFunctionInfo::kCodeOffset);
|
| - isolate_->heap()->mark_compact_collector()->
|
| - RecordSlot(shared_code_slot, shared_code_slot, *shared_code_slot);
|
| -
|
| - candidate = next_candidate;
|
| - }
|
| -
|
| - jsfunction_candidates_head_ = NULL;
|
| -}
|
| -
|
| -
|
| -void CodeFlusher::ProcessSharedFunctionInfoCandidates() {
|
| - Code* lazy_compile =
|
| - isolate_->builtins()->builtin(Builtins::kCompileUnoptimized);
|
| -
|
| - SharedFunctionInfo* candidate = shared_function_info_candidates_head_;
|
| - SharedFunctionInfo* next_candidate;
|
| - while (candidate != NULL) {
|
| - next_candidate = GetNextCandidate(candidate);
|
| - ClearNextCandidate(candidate);
|
| -
|
| - Code* code = candidate->code();
|
| - MarkBit code_mark = Marking::MarkBitFrom(code);
|
| - if (!code_mark.Get()) {
|
| - if (FLAG_trace_code_flushing && candidate->is_compiled()) {
|
| - PrintF("[code-flushing clears: ");
|
| - candidate->ShortPrint();
|
| - PrintF(" - age: %d]\n", code->GetAge());
|
| - }
|
| - candidate->set_code(lazy_compile);
|
| - }
|
| -
|
| - Object** code_slot =
|
| - HeapObject::RawField(candidate, SharedFunctionInfo::kCodeOffset);
|
| - isolate_->heap()->mark_compact_collector()->
|
| - RecordSlot(code_slot, code_slot, *code_slot);
|
| -
|
| - candidate = next_candidate;
|
| - }
|
| -
|
| - shared_function_info_candidates_head_ = NULL;
|
| -}
|
| -
|
| -
|
| -void CodeFlusher::ProcessOptimizedCodeMaps() {
|
| - STATIC_ASSERT(SharedFunctionInfo::kEntryLength == 4);
|
| -
|
| - SharedFunctionInfo* holder = optimized_code_map_holder_head_;
|
| - SharedFunctionInfo* next_holder;
|
| -
|
| - while (holder != NULL) {
|
| - next_holder = GetNextCodeMap(holder);
|
| - ClearNextCodeMap(holder);
|
| -
|
| - FixedArray* code_map = FixedArray::cast(holder->optimized_code_map());
|
| - int new_length = SharedFunctionInfo::kEntriesStart;
|
| - int old_length = code_map->length();
|
| - for (int i = SharedFunctionInfo::kEntriesStart;
|
| - i < old_length;
|
| - i += SharedFunctionInfo::kEntryLength) {
|
| - Code* code =
|
| - Code::cast(code_map->get(i + SharedFunctionInfo::kCachedCodeOffset));
|
| - if (!Marking::MarkBitFrom(code).Get()) continue;
|
| -
|
| - // Move every slot in the entry.
|
| - for (int j = 0; j < SharedFunctionInfo::kEntryLength; j++) {
|
| - int dst_index = new_length++;
|
| - Object** slot = code_map->RawFieldOfElementAt(dst_index);
|
| - Object* object = code_map->get(i + j);
|
| - code_map->set(dst_index, object);
|
| - if (j == SharedFunctionInfo::kOsrAstIdOffset) {
|
| - DCHECK(object->IsSmi());
|
| - } else {
|
| - DCHECK(Marking::IsBlack(
|
| - Marking::MarkBitFrom(HeapObject::cast(*slot))));
|
| - isolate_->heap()->mark_compact_collector()->
|
| - RecordSlot(slot, slot, *slot);
|
| - }
|
| - }
|
| - }
|
| -
|
| - // Trim the optimized code map if entries have been removed.
|
| - if (new_length < old_length) {
|
| - holder->TrimOptimizedCodeMap(old_length - new_length);
|
| - }
|
| -
|
| - holder = next_holder;
|
| - }
|
| -
|
| - optimized_code_map_holder_head_ = NULL;
|
| -}
|
| -
|
| -
|
| -void CodeFlusher::EvictCandidate(SharedFunctionInfo* shared_info) {
|
| - // Make sure previous flushing decisions are revisited.
|
| - isolate_->heap()->incremental_marking()->RecordWrites(shared_info);
|
| -
|
| - if (FLAG_trace_code_flushing) {
|
| - PrintF("[code-flushing abandons function-info: ");
|
| - shared_info->ShortPrint();
|
| - PrintF("]\n");
|
| - }
|
| -
|
| - SharedFunctionInfo* candidate = shared_function_info_candidates_head_;
|
| - SharedFunctionInfo* next_candidate;
|
| - if (candidate == shared_info) {
|
| - next_candidate = GetNextCandidate(shared_info);
|
| - shared_function_info_candidates_head_ = next_candidate;
|
| - ClearNextCandidate(shared_info);
|
| - } else {
|
| - while (candidate != NULL) {
|
| - next_candidate = GetNextCandidate(candidate);
|
| -
|
| - if (next_candidate == shared_info) {
|
| - next_candidate = GetNextCandidate(shared_info);
|
| - SetNextCandidate(candidate, next_candidate);
|
| - ClearNextCandidate(shared_info);
|
| - break;
|
| - }
|
| -
|
| - candidate = next_candidate;
|
| - }
|
| - }
|
| -}
|
| -
|
| -
|
| -void CodeFlusher::EvictCandidate(JSFunction* function) {
|
| - DCHECK(!function->next_function_link()->IsUndefined());
|
| - Object* undefined = isolate_->heap()->undefined_value();
|
| -
|
| - // Make sure previous flushing decisions are revisited.
|
| - isolate_->heap()->incremental_marking()->RecordWrites(function);
|
| - isolate_->heap()->incremental_marking()->RecordWrites(function->shared());
|
| -
|
| - if (FLAG_trace_code_flushing) {
|
| - PrintF("[code-flushing abandons closure: ");
|
| - function->shared()->ShortPrint();
|
| - PrintF("]\n");
|
| - }
|
| -
|
| - JSFunction* candidate = jsfunction_candidates_head_;
|
| - JSFunction* next_candidate;
|
| - if (candidate == function) {
|
| - next_candidate = GetNextCandidate(function);
|
| - jsfunction_candidates_head_ = next_candidate;
|
| - ClearNextCandidate(function, undefined);
|
| - } else {
|
| - while (candidate != NULL) {
|
| - next_candidate = GetNextCandidate(candidate);
|
| -
|
| - if (next_candidate == function) {
|
| - next_candidate = GetNextCandidate(function);
|
| - SetNextCandidate(candidate, next_candidate);
|
| - ClearNextCandidate(function, undefined);
|
| - break;
|
| - }
|
| -
|
| - candidate = next_candidate;
|
| - }
|
| - }
|
| -}
|
| -
|
| -
|
| -void CodeFlusher::EvictOptimizedCodeMap(SharedFunctionInfo* code_map_holder) {
|
| - DCHECK(!FixedArray::cast(code_map_holder->optimized_code_map())->
|
| - get(SharedFunctionInfo::kNextMapIndex)->IsUndefined());
|
| -
|
| - // Make sure previous flushing decisions are revisited.
|
| - isolate_->heap()->incremental_marking()->RecordWrites(code_map_holder);
|
| -
|
| - if (FLAG_trace_code_flushing) {
|
| - PrintF("[code-flushing abandons code-map: ");
|
| - code_map_holder->ShortPrint();
|
| - PrintF("]\n");
|
| - }
|
| -
|
| - SharedFunctionInfo* holder = optimized_code_map_holder_head_;
|
| - SharedFunctionInfo* next_holder;
|
| - if (holder == code_map_holder) {
|
| - next_holder = GetNextCodeMap(code_map_holder);
|
| - optimized_code_map_holder_head_ = next_holder;
|
| - ClearNextCodeMap(code_map_holder);
|
| - } else {
|
| - while (holder != NULL) {
|
| - next_holder = GetNextCodeMap(holder);
|
| -
|
| - if (next_holder == code_map_holder) {
|
| - next_holder = GetNextCodeMap(code_map_holder);
|
| - SetNextCodeMap(holder, next_holder);
|
| - ClearNextCodeMap(code_map_holder);
|
| - break;
|
| - }
|
| -
|
| - holder = next_holder;
|
| - }
|
| - }
|
| -}
|
| -
|
| -
|
| -void CodeFlusher::EvictJSFunctionCandidates() {
|
| - JSFunction* candidate = jsfunction_candidates_head_;
|
| - JSFunction* next_candidate;
|
| - while (candidate != NULL) {
|
| - next_candidate = GetNextCandidate(candidate);
|
| - EvictCandidate(candidate);
|
| - candidate = next_candidate;
|
| - }
|
| - DCHECK(jsfunction_candidates_head_ == NULL);
|
| -}
|
| -
|
| -
|
| -void CodeFlusher::EvictSharedFunctionInfoCandidates() {
|
| - SharedFunctionInfo* candidate = shared_function_info_candidates_head_;
|
| - SharedFunctionInfo* next_candidate;
|
| - while (candidate != NULL) {
|
| - next_candidate = GetNextCandidate(candidate);
|
| - EvictCandidate(candidate);
|
| - candidate = next_candidate;
|
| - }
|
| - DCHECK(shared_function_info_candidates_head_ == NULL);
|
| -}
|
| -
|
| -
|
| -void CodeFlusher::EvictOptimizedCodeMaps() {
|
| - SharedFunctionInfo* holder = optimized_code_map_holder_head_;
|
| - SharedFunctionInfo* next_holder;
|
| - while (holder != NULL) {
|
| - next_holder = GetNextCodeMap(holder);
|
| - EvictOptimizedCodeMap(holder);
|
| - holder = next_holder;
|
| - }
|
| - DCHECK(optimized_code_map_holder_head_ == NULL);
|
| -}
|
| -
|
| -
|
| -void CodeFlusher::IteratePointersToFromSpace(ObjectVisitor* v) {
|
| - Heap* heap = isolate_->heap();
|
| -
|
| - JSFunction** slot = &jsfunction_candidates_head_;
|
| - JSFunction* candidate = jsfunction_candidates_head_;
|
| - while (candidate != NULL) {
|
| - if (heap->InFromSpace(candidate)) {
|
| - v->VisitPointer(reinterpret_cast<Object**>(slot));
|
| - }
|
| - candidate = GetNextCandidate(*slot);
|
| - slot = GetNextCandidateSlot(*slot);
|
| - }
|
| -}
|
| -
|
| -
|
| -MarkCompactCollector::~MarkCompactCollector() {
|
| - if (code_flusher_ != NULL) {
|
| - delete code_flusher_;
|
| - code_flusher_ = NULL;
|
| - }
|
| -}
|
| -
|
| -
|
| -static inline HeapObject* ShortCircuitConsString(Object** p) {
|
| - // Optimization: If the heap object pointed to by p is a non-internalized
|
| - // cons string whose right substring is HEAP->empty_string, update
|
| - // it in place to its left substring. Return the updated value.
|
| - //
|
| - // Here we assume that if we change *p, we replace it with a heap object
|
| - // (i.e., the left substring of a cons string is always a heap object).
|
| - //
|
| - // The check performed is:
|
| - // object->IsConsString() && !object->IsInternalizedString() &&
|
| - // (ConsString::cast(object)->second() == HEAP->empty_string())
|
| - // except the maps for the object and its possible substrings might be
|
| - // marked.
|
| - HeapObject* object = HeapObject::cast(*p);
|
| - if (!FLAG_clever_optimizations) return object;
|
| - Map* map = object->map();
|
| - InstanceType type = map->instance_type();
|
| - if (!IsShortcutCandidate(type)) return object;
|
| -
|
| - Object* second = reinterpret_cast<ConsString*>(object)->second();
|
| - Heap* heap = map->GetHeap();
|
| - if (second != heap->empty_string()) {
|
| - return object;
|
| - }
|
| -
|
| - // Since we don't have the object's start, it is impossible to update the
|
| - // page dirty marks. Therefore, we only replace the string with its left
|
| - // substring when page dirty marks do not change.
|
| - Object* first = reinterpret_cast<ConsString*>(object)->first();
|
| - if (!heap->InNewSpace(object) && heap->InNewSpace(first)) return object;
|
| -
|
| - *p = first;
|
| - return HeapObject::cast(first);
|
| -}
|
| -
|
| -
|
| -class MarkCompactMarkingVisitor
|
| - : public StaticMarkingVisitor<MarkCompactMarkingVisitor> {
|
| - public:
|
| - static void ObjectStatsVisitBase(StaticVisitorBase::VisitorId id,
|
| - Map* map, HeapObject* obj);
|
| -
|
| - static void ObjectStatsCountFixedArray(
|
| - FixedArrayBase* fixed_array,
|
| - FixedArraySubInstanceType fast_type,
|
| - FixedArraySubInstanceType dictionary_type);
|
| -
|
| - template<MarkCompactMarkingVisitor::VisitorId id>
|
| - class ObjectStatsTracker {
|
| - public:
|
| - static inline void Visit(Map* map, HeapObject* obj);
|
| - };
|
| -
|
| - static void Initialize();
|
| -
|
| - INLINE(static void VisitPointer(Heap* heap, Object** p)) {
|
| - MarkObjectByPointer(heap->mark_compact_collector(), p, p);
|
| - }
|
| -
|
| - INLINE(static void VisitPointers(Heap* heap, Object** start, Object** end)) {
|
| - // Mark all objects pointed to in [start, end).
|
| - const int kMinRangeForMarkingRecursion = 64;
|
| - if (end - start >= kMinRangeForMarkingRecursion) {
|
| - if (VisitUnmarkedObjects(heap, start, end)) return;
|
| - // We are close to a stack overflow, so just mark the objects.
|
| - }
|
| - MarkCompactCollector* collector = heap->mark_compact_collector();
|
| - for (Object** p = start; p < end; p++) {
|
| - MarkObjectByPointer(collector, start, p);
|
| - }
|
| - }
|
| -
|
| - // Marks the object black and pushes it on the marking stack.
|
| - INLINE(static void MarkObject(Heap* heap, HeapObject* object)) {
|
| - MarkBit mark = Marking::MarkBitFrom(object);
|
| - heap->mark_compact_collector()->MarkObject(object, mark);
|
| - }
|
| -
|
| - // Marks the object black without pushing it on the marking stack.
|
| - // Returns true if object needed marking and false otherwise.
|
| - INLINE(static bool MarkObjectWithoutPush(Heap* heap, HeapObject* object)) {
|
| - MarkBit mark_bit = Marking::MarkBitFrom(object);
|
| - if (!mark_bit.Get()) {
|
| - heap->mark_compact_collector()->SetMark(object, mark_bit);
|
| - return true;
|
| - }
|
| - return false;
|
| - }
|
| -
|
| - // Mark object pointed to by p.
|
| - INLINE(static void MarkObjectByPointer(MarkCompactCollector* collector,
|
| - Object** anchor_slot,
|
| - Object** p)) {
|
| - if (!(*p)->IsHeapObject()) return;
|
| - HeapObject* object = ShortCircuitConsString(p);
|
| - collector->RecordSlot(anchor_slot, p, object);
|
| - MarkBit mark = Marking::MarkBitFrom(object);
|
| - collector->MarkObject(object, mark);
|
| - }
|
| -
|
| -
|
| - // Visit an unmarked object.
|
| - INLINE(static void VisitUnmarkedObject(MarkCompactCollector* collector,
|
| - HeapObject* obj)) {
|
| -#ifdef DEBUG
|
| - DCHECK(collector->heap()->Contains(obj));
|
| - DCHECK(!collector->heap()->mark_compact_collector()->IsMarked(obj));
|
| -#endif
|
| - Map* map = obj->map();
|
| - Heap* heap = obj->GetHeap();
|
| - MarkBit mark = Marking::MarkBitFrom(obj);
|
| - heap->mark_compact_collector()->SetMark(obj, mark);
|
| - // Mark the map pointer and the body.
|
| - MarkBit map_mark = Marking::MarkBitFrom(map);
|
| - heap->mark_compact_collector()->MarkObject(map, map_mark);
|
| - IterateBody(map, obj);
|
| - }
|
| -
|
| - // Visit all unmarked objects pointed to by [start, end).
|
| - // Returns false if the operation fails (lack of stack space).
|
| - INLINE(static bool VisitUnmarkedObjects(Heap* heap,
|
| - Object** start,
|
| - Object** end)) {
|
| - // Return false is we are close to the stack limit.
|
| - StackLimitCheck check(heap->isolate());
|
| - if (check.HasOverflowed()) return false;
|
| -
|
| - MarkCompactCollector* collector = heap->mark_compact_collector();
|
| - // Visit the unmarked objects.
|
| - for (Object** p = start; p < end; p++) {
|
| - Object* o = *p;
|
| - if (!o->IsHeapObject()) continue;
|
| - collector->RecordSlot(start, p, o);
|
| - HeapObject* obj = HeapObject::cast(o);
|
| - MarkBit mark = Marking::MarkBitFrom(obj);
|
| - if (mark.Get()) continue;
|
| - VisitUnmarkedObject(collector, obj);
|
| - }
|
| - return true;
|
| - }
|
| -
|
| - private:
|
| - template<int id>
|
| - static inline void TrackObjectStatsAndVisit(Map* map, HeapObject* obj);
|
| -
|
| - // Code flushing support.
|
| -
|
| - static const int kRegExpCodeThreshold = 5;
|
| -
|
| - static void UpdateRegExpCodeAgeAndFlush(Heap* heap,
|
| - JSRegExp* re,
|
| - bool is_ascii) {
|
| - // Make sure that the fixed array is in fact initialized on the RegExp.
|
| - // We could potentially trigger a GC when initializing the RegExp.
|
| - if (HeapObject::cast(re->data())->map()->instance_type() !=
|
| - FIXED_ARRAY_TYPE) return;
|
| -
|
| - // Make sure this is a RegExp that actually contains code.
|
| - if (re->TypeTag() != JSRegExp::IRREGEXP) return;
|
| -
|
| - Object* code = re->DataAt(JSRegExp::code_index(is_ascii));
|
| - if (!code->IsSmi() &&
|
| - HeapObject::cast(code)->map()->instance_type() == CODE_TYPE) {
|
| - // Save a copy that can be reinstated if we need the code again.
|
| - re->SetDataAt(JSRegExp::saved_code_index(is_ascii), code);
|
| -
|
| - // Saving a copy might create a pointer into compaction candidate
|
| - // that was not observed by marker. This might happen if JSRegExp data
|
| - // was marked through the compilation cache before marker reached JSRegExp
|
| - // object.
|
| - FixedArray* data = FixedArray::cast(re->data());
|
| - Object** slot = data->data_start() + JSRegExp::saved_code_index(is_ascii);
|
| - heap->mark_compact_collector()->
|
| - RecordSlot(slot, slot, code);
|
| -
|
| - // Set a number in the 0-255 range to guarantee no smi overflow.
|
| - re->SetDataAt(JSRegExp::code_index(is_ascii),
|
| - Smi::FromInt(heap->sweep_generation() & 0xff));
|
| - } else if (code->IsSmi()) {
|
| - int value = Smi::cast(code)->value();
|
| - // The regexp has not been compiled yet or there was a compilation error.
|
| - if (value == JSRegExp::kUninitializedValue ||
|
| - value == JSRegExp::kCompilationErrorValue) {
|
| - return;
|
| - }
|
| -
|
| - // Check if we should flush now.
|
| - if (value == ((heap->sweep_generation() - kRegExpCodeThreshold) & 0xff)) {
|
| - re->SetDataAt(JSRegExp::code_index(is_ascii),
|
| - Smi::FromInt(JSRegExp::kUninitializedValue));
|
| - re->SetDataAt(JSRegExp::saved_code_index(is_ascii),
|
| - Smi::FromInt(JSRegExp::kUninitializedValue));
|
| - }
|
| - }
|
| - }
|
| -
|
| -
|
| - // Works by setting the current sweep_generation (as a smi) in the
|
| - // code object place in the data array of the RegExp and keeps a copy
|
| - // around that can be reinstated if we reuse the RegExp before flushing.
|
| - // If we did not use the code for kRegExpCodeThreshold mark sweep GCs
|
| - // we flush the code.
|
| - static void VisitRegExpAndFlushCode(Map* map, HeapObject* object) {
|
| - Heap* heap = map->GetHeap();
|
| - MarkCompactCollector* collector = heap->mark_compact_collector();
|
| - if (!collector->is_code_flushing_enabled()) {
|
| - VisitJSRegExp(map, object);
|
| - return;
|
| - }
|
| - JSRegExp* re = reinterpret_cast<JSRegExp*>(object);
|
| - // Flush code or set age on both ASCII and two byte code.
|
| - UpdateRegExpCodeAgeAndFlush(heap, re, true);
|
| - UpdateRegExpCodeAgeAndFlush(heap, re, false);
|
| - // Visit the fields of the RegExp, including the updated FixedArray.
|
| - VisitJSRegExp(map, object);
|
| - }
|
| -
|
| - static VisitorDispatchTable<Callback> non_count_table_;
|
| -};
|
| -
|
| -
|
| -void MarkCompactMarkingVisitor::ObjectStatsCountFixedArray(
|
| - FixedArrayBase* fixed_array,
|
| - FixedArraySubInstanceType fast_type,
|
| - FixedArraySubInstanceType dictionary_type) {
|
| - Heap* heap = fixed_array->map()->GetHeap();
|
| - if (fixed_array->map() != heap->fixed_cow_array_map() &&
|
| - fixed_array->map() != heap->fixed_double_array_map() &&
|
| - fixed_array != heap->empty_fixed_array()) {
|
| - if (fixed_array->IsDictionary()) {
|
| - heap->RecordFixedArraySubTypeStats(dictionary_type,
|
| - fixed_array->Size());
|
| - } else {
|
| - heap->RecordFixedArraySubTypeStats(fast_type,
|
| - fixed_array->Size());
|
| - }
|
| - }
|
| -}
|
| -
|
| -
|
| -void MarkCompactMarkingVisitor::ObjectStatsVisitBase(
|
| - MarkCompactMarkingVisitor::VisitorId id, Map* map, HeapObject* obj) {
|
| - Heap* heap = map->GetHeap();
|
| - int object_size = obj->Size();
|
| - heap->RecordObjectStats(map->instance_type(), object_size);
|
| - non_count_table_.GetVisitorById(id)(map, obj);
|
| - if (obj->IsJSObject()) {
|
| - JSObject* object = JSObject::cast(obj);
|
| - ObjectStatsCountFixedArray(object->elements(),
|
| - DICTIONARY_ELEMENTS_SUB_TYPE,
|
| - FAST_ELEMENTS_SUB_TYPE);
|
| - ObjectStatsCountFixedArray(object->properties(),
|
| - DICTIONARY_PROPERTIES_SUB_TYPE,
|
| - FAST_PROPERTIES_SUB_TYPE);
|
| - }
|
| -}
|
| -
|
| -
|
| -template<MarkCompactMarkingVisitor::VisitorId id>
|
| -void MarkCompactMarkingVisitor::ObjectStatsTracker<id>::Visit(
|
| - Map* map, HeapObject* obj) {
|
| - ObjectStatsVisitBase(id, map, obj);
|
| -}
|
| -
|
| -
|
| -template<>
|
| -class MarkCompactMarkingVisitor::ObjectStatsTracker<
|
| - MarkCompactMarkingVisitor::kVisitMap> {
|
| - public:
|
| - static inline void Visit(Map* map, HeapObject* obj) {
|
| - Heap* heap = map->GetHeap();
|
| - Map* map_obj = Map::cast(obj);
|
| - DCHECK(map->instance_type() == MAP_TYPE);
|
| - DescriptorArray* array = map_obj->instance_descriptors();
|
| - if (map_obj->owns_descriptors() &&
|
| - array != heap->empty_descriptor_array()) {
|
| - int fixed_array_size = array->Size();
|
| - heap->RecordFixedArraySubTypeStats(DESCRIPTOR_ARRAY_SUB_TYPE,
|
| - fixed_array_size);
|
| - }
|
| - if (map_obj->HasTransitionArray()) {
|
| - int fixed_array_size = map_obj->transitions()->Size();
|
| - heap->RecordFixedArraySubTypeStats(TRANSITION_ARRAY_SUB_TYPE,
|
| - fixed_array_size);
|
| - }
|
| - if (map_obj->has_code_cache()) {
|
| - CodeCache* cache = CodeCache::cast(map_obj->code_cache());
|
| - heap->RecordFixedArraySubTypeStats(MAP_CODE_CACHE_SUB_TYPE,
|
| - cache->default_cache()->Size());
|
| - if (!cache->normal_type_cache()->IsUndefined()) {
|
| - heap->RecordFixedArraySubTypeStats(
|
| - MAP_CODE_CACHE_SUB_TYPE,
|
| - FixedArray::cast(cache->normal_type_cache())->Size());
|
| - }
|
| - }
|
| - ObjectStatsVisitBase(kVisitMap, map, obj);
|
| - }
|
| -};
|
| -
|
| -
|
| -template<>
|
| -class MarkCompactMarkingVisitor::ObjectStatsTracker<
|
| - MarkCompactMarkingVisitor::kVisitCode> {
|
| - public:
|
| - static inline void Visit(Map* map, HeapObject* obj) {
|
| - Heap* heap = map->GetHeap();
|
| - int object_size = obj->Size();
|
| - DCHECK(map->instance_type() == CODE_TYPE);
|
| - Code* code_obj = Code::cast(obj);
|
| - heap->RecordCodeSubTypeStats(code_obj->kind(), code_obj->GetRawAge(),
|
| - object_size);
|
| - ObjectStatsVisitBase(kVisitCode, map, obj);
|
| - }
|
| -};
|
| -
|
| -
|
| -template<>
|
| -class MarkCompactMarkingVisitor::ObjectStatsTracker<
|
| - MarkCompactMarkingVisitor::kVisitSharedFunctionInfo> {
|
| - public:
|
| - static inline void Visit(Map* map, HeapObject* obj) {
|
| - Heap* heap = map->GetHeap();
|
| - SharedFunctionInfo* sfi = SharedFunctionInfo::cast(obj);
|
| - if (sfi->scope_info() != heap->empty_fixed_array()) {
|
| - heap->RecordFixedArraySubTypeStats(
|
| - SCOPE_INFO_SUB_TYPE,
|
| - FixedArray::cast(sfi->scope_info())->Size());
|
| - }
|
| - ObjectStatsVisitBase(kVisitSharedFunctionInfo, map, obj);
|
| - }
|
| -};
|
| -
|
| -
|
| -template<>
|
| -class MarkCompactMarkingVisitor::ObjectStatsTracker<
|
| - MarkCompactMarkingVisitor::kVisitFixedArray> {
|
| - public:
|
| - static inline void Visit(Map* map, HeapObject* obj) {
|
| - Heap* heap = map->GetHeap();
|
| - FixedArray* fixed_array = FixedArray::cast(obj);
|
| - if (fixed_array == heap->string_table()) {
|
| - heap->RecordFixedArraySubTypeStats(
|
| - STRING_TABLE_SUB_TYPE,
|
| - fixed_array->Size());
|
| - }
|
| - ObjectStatsVisitBase(kVisitFixedArray, map, obj);
|
| - }
|
| -};
|
| -
|
| -
|
| -void MarkCompactMarkingVisitor::Initialize() {
|
| - StaticMarkingVisitor<MarkCompactMarkingVisitor>::Initialize();
|
| -
|
| - table_.Register(kVisitJSRegExp,
|
| - &VisitRegExpAndFlushCode);
|
| -
|
| - if (FLAG_track_gc_object_stats) {
|
| - // Copy the visitor table to make call-through possible.
|
| - non_count_table_.CopyFrom(&table_);
|
| -#define VISITOR_ID_COUNT_FUNCTION(id) \
|
| - table_.Register(kVisit##id, ObjectStatsTracker<kVisit##id>::Visit);
|
| - VISITOR_ID_LIST(VISITOR_ID_COUNT_FUNCTION)
|
| -#undef VISITOR_ID_COUNT_FUNCTION
|
| - }
|
| -}
|
| -
|
| -
|
| -VisitorDispatchTable<MarkCompactMarkingVisitor::Callback>
|
| - MarkCompactMarkingVisitor::non_count_table_;
|
| -
|
| -
|
| -class CodeMarkingVisitor : public ThreadVisitor {
|
| - public:
|
| - explicit CodeMarkingVisitor(MarkCompactCollector* collector)
|
| - : collector_(collector) {}
|
| -
|
| - void VisitThread(Isolate* isolate, ThreadLocalTop* top) {
|
| - collector_->PrepareThreadForCodeFlushing(isolate, top);
|
| - }
|
| -
|
| - private:
|
| - MarkCompactCollector* collector_;
|
| -};
|
| -
|
| -
|
| -class SharedFunctionInfoMarkingVisitor : public ObjectVisitor {
|
| - public:
|
| - explicit SharedFunctionInfoMarkingVisitor(MarkCompactCollector* collector)
|
| - : collector_(collector) {}
|
| -
|
| - void VisitPointers(Object** start, Object** end) {
|
| - for (Object** p = start; p < end; p++) VisitPointer(p);
|
| - }
|
| -
|
| - void VisitPointer(Object** slot) {
|
| - Object* obj = *slot;
|
| - if (obj->IsSharedFunctionInfo()) {
|
| - SharedFunctionInfo* shared = reinterpret_cast<SharedFunctionInfo*>(obj);
|
| - MarkBit shared_mark = Marking::MarkBitFrom(shared);
|
| - MarkBit code_mark = Marking::MarkBitFrom(shared->code());
|
| - collector_->MarkObject(shared->code(), code_mark);
|
| - collector_->MarkObject(shared, shared_mark);
|
| - }
|
| - }
|
| -
|
| - private:
|
| - MarkCompactCollector* collector_;
|
| -};
|
| -
|
| -
|
| -void MarkCompactCollector::PrepareThreadForCodeFlushing(Isolate* isolate,
|
| - ThreadLocalTop* top) {
|
| - for (StackFrameIterator it(isolate, top); !it.done(); it.Advance()) {
|
| - // Note: for the frame that has a pending lazy deoptimization
|
| - // StackFrame::unchecked_code will return a non-optimized code object for
|
| - // the outermost function and StackFrame::LookupCode will return
|
| - // actual optimized code object.
|
| - StackFrame* frame = it.frame();
|
| - Code* code = frame->unchecked_code();
|
| - MarkBit code_mark = Marking::MarkBitFrom(code);
|
| - MarkObject(code, code_mark);
|
| - if (frame->is_optimized()) {
|
| - MarkCompactMarkingVisitor::MarkInlinedFunctionsCode(heap(),
|
| - frame->LookupCode());
|
| - }
|
| - }
|
| -}
|
| -
|
| -
|
| -void MarkCompactCollector::PrepareForCodeFlushing() {
|
| - // Enable code flushing for non-incremental cycles.
|
| - if (FLAG_flush_code && !FLAG_flush_code_incrementally) {
|
| - EnableCodeFlushing(!was_marked_incrementally_);
|
| - }
|
| -
|
| - // If code flushing is disabled, there is no need to prepare for it.
|
| - if (!is_code_flushing_enabled()) return;
|
| -
|
| - // Ensure that empty descriptor array is marked. Method MarkDescriptorArray
|
| - // relies on it being marked before any other descriptor array.
|
| - HeapObject* descriptor_array = heap()->empty_descriptor_array();
|
| - MarkBit descriptor_array_mark = Marking::MarkBitFrom(descriptor_array);
|
| - MarkObject(descriptor_array, descriptor_array_mark);
|
| -
|
| - // Make sure we are not referencing the code from the stack.
|
| - DCHECK(this == heap()->mark_compact_collector());
|
| - PrepareThreadForCodeFlushing(heap()->isolate(),
|
| - heap()->isolate()->thread_local_top());
|
| -
|
| - // Iterate the archived stacks in all threads to check if
|
| - // the code is referenced.
|
| - CodeMarkingVisitor code_marking_visitor(this);
|
| - heap()->isolate()->thread_manager()->IterateArchivedThreads(
|
| - &code_marking_visitor);
|
| -
|
| - SharedFunctionInfoMarkingVisitor visitor(this);
|
| - heap()->isolate()->compilation_cache()->IterateFunctions(&visitor);
|
| - heap()->isolate()->handle_scope_implementer()->Iterate(&visitor);
|
| -
|
| - ProcessMarkingDeque();
|
| -}
|
| -
|
| -
|
| -// Visitor class for marking heap roots.
|
| -class RootMarkingVisitor : public ObjectVisitor {
|
| - public:
|
| - explicit RootMarkingVisitor(Heap* heap)
|
| - : collector_(heap->mark_compact_collector()) { }
|
| -
|
| - void VisitPointer(Object** p) {
|
| - MarkObjectByPointer(p);
|
| - }
|
| -
|
| - void VisitPointers(Object** start, Object** end) {
|
| - for (Object** p = start; p < end; p++) MarkObjectByPointer(p);
|
| - }
|
| -
|
| - // Skip the weak next code link in a code object, which is visited in
|
| - // ProcessTopOptimizedFrame.
|
| - void VisitNextCodeLink(Object** p) { }
|
| -
|
| - private:
|
| - void MarkObjectByPointer(Object** p) {
|
| - if (!(*p)->IsHeapObject()) return;
|
| -
|
| - // Replace flat cons strings in place.
|
| - HeapObject* object = ShortCircuitConsString(p);
|
| - MarkBit mark_bit = Marking::MarkBitFrom(object);
|
| - if (mark_bit.Get()) return;
|
| -
|
| - Map* map = object->map();
|
| - // Mark the object.
|
| - collector_->SetMark(object, mark_bit);
|
| -
|
| - // Mark the map pointer and body, and push them on the marking stack.
|
| - MarkBit map_mark = Marking::MarkBitFrom(map);
|
| - collector_->MarkObject(map, map_mark);
|
| - MarkCompactMarkingVisitor::IterateBody(map, object);
|
| -
|
| - // Mark all the objects reachable from the map and body. May leave
|
| - // overflowed objects in the heap.
|
| - collector_->EmptyMarkingDeque();
|
| - }
|
| -
|
| - MarkCompactCollector* collector_;
|
| -};
|
| -
|
| -
|
| -// Helper class for pruning the string table.
|
| -template<bool finalize_external_strings>
|
| -class StringTableCleaner : public ObjectVisitor {
|
| - public:
|
| - explicit StringTableCleaner(Heap* heap)
|
| - : heap_(heap), pointers_removed_(0) { }
|
| -
|
| - virtual void VisitPointers(Object** start, Object** end) {
|
| - // Visit all HeapObject pointers in [start, end).
|
| - for (Object** p = start; p < end; p++) {
|
| - Object* o = *p;
|
| - if (o->IsHeapObject() &&
|
| - !Marking::MarkBitFrom(HeapObject::cast(o)).Get()) {
|
| - if (finalize_external_strings) {
|
| - DCHECK(o->IsExternalString());
|
| - heap_->FinalizeExternalString(String::cast(*p));
|
| - } else {
|
| - pointers_removed_++;
|
| - }
|
| - // Set the entry to the_hole_value (as deleted).
|
| - *p = heap_->the_hole_value();
|
| - }
|
| - }
|
| - }
|
| -
|
| - int PointersRemoved() {
|
| - DCHECK(!finalize_external_strings);
|
| - return pointers_removed_;
|
| - }
|
| -
|
| - private:
|
| - Heap* heap_;
|
| - int pointers_removed_;
|
| -};
|
| -
|
| -
|
| -typedef StringTableCleaner<false> InternalizedStringTableCleaner;
|
| -typedef StringTableCleaner<true> ExternalStringTableCleaner;
|
| -
|
| -
|
| -// Implementation of WeakObjectRetainer for mark compact GCs. All marked objects
|
| -// are retained.
|
| -class MarkCompactWeakObjectRetainer : public WeakObjectRetainer {
|
| - public:
|
| - virtual Object* RetainAs(Object* object) {
|
| - if (Marking::MarkBitFrom(HeapObject::cast(object)).Get()) {
|
| - return object;
|
| - } else if (object->IsAllocationSite() &&
|
| - !(AllocationSite::cast(object)->IsZombie())) {
|
| - // "dead" AllocationSites need to live long enough for a traversal of new
|
| - // space. These sites get a one-time reprieve.
|
| - AllocationSite* site = AllocationSite::cast(object);
|
| - site->MarkZombie();
|
| - site->GetHeap()->mark_compact_collector()->MarkAllocationSite(site);
|
| - return object;
|
| - } else {
|
| - return NULL;
|
| - }
|
| - }
|
| -};
|
| -
|
| -
|
| -// Fill the marking stack with overflowed objects returned by the given
|
| -// iterator. Stop when the marking stack is filled or the end of the space
|
| -// is reached, whichever comes first.
|
| -template<class T>
|
| -static void DiscoverGreyObjectsWithIterator(Heap* heap,
|
| - MarkingDeque* marking_deque,
|
| - T* it) {
|
| - // The caller should ensure that the marking stack is initially not full,
|
| - // so that we don't waste effort pointlessly scanning for objects.
|
| - DCHECK(!marking_deque->IsFull());
|
| -
|
| - Map* filler_map = heap->one_pointer_filler_map();
|
| - for (HeapObject* object = it->Next();
|
| - object != NULL;
|
| - object = it->Next()) {
|
| - MarkBit markbit = Marking::MarkBitFrom(object);
|
| - if ((object->map() != filler_map) && Marking::IsGrey(markbit)) {
|
| - Marking::GreyToBlack(markbit);
|
| - MemoryChunk::IncrementLiveBytesFromGC(object->address(), object->Size());
|
| - marking_deque->PushBlack(object);
|
| - if (marking_deque->IsFull()) return;
|
| - }
|
| - }
|
| -}
|
| -
|
| -
|
| -static inline int MarkWordToObjectStarts(uint32_t mark_bits, int* starts);
|
| -
|
| -
|
| -static void DiscoverGreyObjectsOnPage(MarkingDeque* marking_deque,
|
| - MemoryChunk* p) {
|
| - DCHECK(!marking_deque->IsFull());
|
| - DCHECK(strcmp(Marking::kWhiteBitPattern, "00") == 0);
|
| - DCHECK(strcmp(Marking::kBlackBitPattern, "10") == 0);
|
| - DCHECK(strcmp(Marking::kGreyBitPattern, "11") == 0);
|
| - DCHECK(strcmp(Marking::kImpossibleBitPattern, "01") == 0);
|
| -
|
| - for (MarkBitCellIterator it(p); !it.Done(); it.Advance()) {
|
| - Address cell_base = it.CurrentCellBase();
|
| - MarkBit::CellType* cell = it.CurrentCell();
|
| -
|
| - const MarkBit::CellType current_cell = *cell;
|
| - if (current_cell == 0) continue;
|
| -
|
| - MarkBit::CellType grey_objects;
|
| - if (it.HasNext()) {
|
| - const MarkBit::CellType next_cell = *(cell+1);
|
| - grey_objects = current_cell &
|
| - ((current_cell >> 1) | (next_cell << (Bitmap::kBitsPerCell - 1)));
|
| - } else {
|
| - grey_objects = current_cell & (current_cell >> 1);
|
| - }
|
| -
|
| - int offset = 0;
|
| - while (grey_objects != 0) {
|
| - int trailing_zeros = CompilerIntrinsics::CountTrailingZeros(grey_objects);
|
| - grey_objects >>= trailing_zeros;
|
| - offset += trailing_zeros;
|
| - MarkBit markbit(cell, 1 << offset, false);
|
| - DCHECK(Marking::IsGrey(markbit));
|
| - Marking::GreyToBlack(markbit);
|
| - Address addr = cell_base + offset * kPointerSize;
|
| - HeapObject* object = HeapObject::FromAddress(addr);
|
| - MemoryChunk::IncrementLiveBytesFromGC(object->address(), object->Size());
|
| - marking_deque->PushBlack(object);
|
| - if (marking_deque->IsFull()) return;
|
| - offset += 2;
|
| - grey_objects >>= 2;
|
| - }
|
| -
|
| - grey_objects >>= (Bitmap::kBitsPerCell - 1);
|
| - }
|
| -}
|
| -
|
| -
|
| -int MarkCompactCollector::DiscoverAndEvacuateBlackObjectsOnPage(
|
| - NewSpace* new_space,
|
| - NewSpacePage* p) {
|
| - DCHECK(strcmp(Marking::kWhiteBitPattern, "00") == 0);
|
| - DCHECK(strcmp(Marking::kBlackBitPattern, "10") == 0);
|
| - DCHECK(strcmp(Marking::kGreyBitPattern, "11") == 0);
|
| - DCHECK(strcmp(Marking::kImpossibleBitPattern, "01") == 0);
|
| -
|
| - MarkBit::CellType* cells = p->markbits()->cells();
|
| - int survivors_size = 0;
|
| -
|
| - for (MarkBitCellIterator it(p); !it.Done(); it.Advance()) {
|
| - Address cell_base = it.CurrentCellBase();
|
| - MarkBit::CellType* cell = it.CurrentCell();
|
| -
|
| - MarkBit::CellType current_cell = *cell;
|
| - if (current_cell == 0) continue;
|
| -
|
| - int offset = 0;
|
| - while (current_cell != 0) {
|
| - int trailing_zeros = CompilerIntrinsics::CountTrailingZeros(current_cell);
|
| - current_cell >>= trailing_zeros;
|
| - offset += trailing_zeros;
|
| - Address address = cell_base + offset * kPointerSize;
|
| - HeapObject* object = HeapObject::FromAddress(address);
|
| -
|
| - int size = object->Size();
|
| - survivors_size += size;
|
| -
|
| - Heap::UpdateAllocationSiteFeedback(object, Heap::RECORD_SCRATCHPAD_SLOT);
|
| -
|
| - offset++;
|
| - current_cell >>= 1;
|
| -
|
| - // TODO(hpayer): Refactor EvacuateObject and call this function instead.
|
| - if (heap()->ShouldBePromoted(object->address(), size) &&
|
| - TryPromoteObject(object, size)) {
|
| - continue;
|
| - }
|
| -
|
| - AllocationResult allocation = new_space->AllocateRaw(size);
|
| - if (allocation.IsRetry()) {
|
| - if (!new_space->AddFreshPage()) {
|
| - // Shouldn't happen. We are sweeping linearly, and to-space
|
| - // has the same number of pages as from-space, so there is
|
| - // always room.
|
| - UNREACHABLE();
|
| - }
|
| - allocation = new_space->AllocateRaw(size);
|
| - DCHECK(!allocation.IsRetry());
|
| - }
|
| - Object* target = allocation.ToObjectChecked();
|
| -
|
| - MigrateObject(HeapObject::cast(target),
|
| - object,
|
| - size,
|
| - NEW_SPACE);
|
| - heap()->IncrementSemiSpaceCopiedObjectSize(size);
|
| - }
|
| - *cells = 0;
|
| - }
|
| - return survivors_size;
|
| -}
|
| -
|
| -
|
| -static void DiscoverGreyObjectsInSpace(Heap* heap,
|
| - MarkingDeque* marking_deque,
|
| - PagedSpace* space) {
|
| - if (space->swept_precisely()) {
|
| - HeapObjectIterator it(space);
|
| - DiscoverGreyObjectsWithIterator(heap, marking_deque, &it);
|
| - } else {
|
| - PageIterator it(space);
|
| - while (it.has_next()) {
|
| - Page* p = it.next();
|
| - DiscoverGreyObjectsOnPage(marking_deque, p);
|
| - if (marking_deque->IsFull()) return;
|
| - }
|
| - }
|
| -}
|
| -
|
| -
|
| -static void DiscoverGreyObjectsInNewSpace(Heap* heap,
|
| - MarkingDeque* marking_deque) {
|
| - NewSpace* space = heap->new_space();
|
| - NewSpacePageIterator it(space->bottom(), space->top());
|
| - while (it.has_next()) {
|
| - NewSpacePage* page = it.next();
|
| - DiscoverGreyObjectsOnPage(marking_deque, page);
|
| - if (marking_deque->IsFull()) return;
|
| - }
|
| -}
|
| -
|
| -
|
| -bool MarkCompactCollector::IsUnmarkedHeapObject(Object** p) {
|
| - Object* o = *p;
|
| - if (!o->IsHeapObject()) return false;
|
| - HeapObject* heap_object = HeapObject::cast(o);
|
| - MarkBit mark = Marking::MarkBitFrom(heap_object);
|
| - return !mark.Get();
|
| -}
|
| -
|
| -
|
| -bool MarkCompactCollector::IsUnmarkedHeapObjectWithHeap(Heap* heap,
|
| - Object** p) {
|
| - Object* o = *p;
|
| - DCHECK(o->IsHeapObject());
|
| - HeapObject* heap_object = HeapObject::cast(o);
|
| - MarkBit mark = Marking::MarkBitFrom(heap_object);
|
| - return !mark.Get();
|
| -}
|
| -
|
| -
|
| -void MarkCompactCollector::MarkStringTable(RootMarkingVisitor* visitor) {
|
| - StringTable* string_table = heap()->string_table();
|
| - // Mark the string table itself.
|
| - MarkBit string_table_mark = Marking::MarkBitFrom(string_table);
|
| - if (!string_table_mark.Get()) {
|
| - // String table could have already been marked by visiting the handles list.
|
| - SetMark(string_table, string_table_mark);
|
| - }
|
| - // Explicitly mark the prefix.
|
| - string_table->IteratePrefix(visitor);
|
| - ProcessMarkingDeque();
|
| -}
|
| -
|
| -
|
| -void MarkCompactCollector::MarkAllocationSite(AllocationSite* site) {
|
| - MarkBit mark_bit = Marking::MarkBitFrom(site);
|
| - SetMark(site, mark_bit);
|
| -}
|
| -
|
| -
|
| -void MarkCompactCollector::MarkRoots(RootMarkingVisitor* visitor) {
|
| - // Mark the heap roots including global variables, stack variables,
|
| - // etc., and all objects reachable from them.
|
| - heap()->IterateStrongRoots(visitor, VISIT_ONLY_STRONG);
|
| -
|
| - // Handle the string table specially.
|
| - MarkStringTable(visitor);
|
| -
|
| - MarkWeakObjectToCodeTable();
|
| -
|
| - // There may be overflowed objects in the heap. Visit them now.
|
| - while (marking_deque_.overflowed()) {
|
| - RefillMarkingDeque();
|
| - EmptyMarkingDeque();
|
| - }
|
| -}
|
| -
|
| -
|
| -void MarkCompactCollector::MarkImplicitRefGroups() {
|
| - List<ImplicitRefGroup*>* ref_groups =
|
| - isolate()->global_handles()->implicit_ref_groups();
|
| -
|
| - int last = 0;
|
| - for (int i = 0; i < ref_groups->length(); i++) {
|
| - ImplicitRefGroup* entry = ref_groups->at(i);
|
| - DCHECK(entry != NULL);
|
| -
|
| - if (!IsMarked(*entry->parent)) {
|
| - (*ref_groups)[last++] = entry;
|
| - continue;
|
| - }
|
| -
|
| - Object*** children = entry->children;
|
| - // A parent object is marked, so mark all child heap objects.
|
| - for (size_t j = 0; j < entry->length; ++j) {
|
| - if ((*children[j])->IsHeapObject()) {
|
| - HeapObject* child = HeapObject::cast(*children[j]);
|
| - MarkBit mark = Marking::MarkBitFrom(child);
|
| - MarkObject(child, mark);
|
| - }
|
| - }
|
| -
|
| - // Once the entire group has been marked, dispose it because it's
|
| - // not needed anymore.
|
| - delete entry;
|
| - }
|
| - ref_groups->Rewind(last);
|
| -}
|
| -
|
| -
|
| -void MarkCompactCollector::MarkWeakObjectToCodeTable() {
|
| - HeapObject* weak_object_to_code_table =
|
| - HeapObject::cast(heap()->weak_object_to_code_table());
|
| - if (!IsMarked(weak_object_to_code_table)) {
|
| - MarkBit mark = Marking::MarkBitFrom(weak_object_to_code_table);
|
| - SetMark(weak_object_to_code_table, mark);
|
| - }
|
| -}
|
| -
|
| -
|
| -// Mark all objects reachable from the objects on the marking stack.
|
| -// Before: the marking stack contains zero or more heap object pointers.
|
| -// After: the marking stack is empty, and all objects reachable from the
|
| -// marking stack have been marked, or are overflowed in the heap.
|
| -void MarkCompactCollector::EmptyMarkingDeque() {
|
| - while (!marking_deque_.IsEmpty()) {
|
| - HeapObject* object = marking_deque_.Pop();
|
| - DCHECK(object->IsHeapObject());
|
| - DCHECK(heap()->Contains(object));
|
| - DCHECK(Marking::IsBlack(Marking::MarkBitFrom(object)));
|
| -
|
| - Map* map = object->map();
|
| - MarkBit map_mark = Marking::MarkBitFrom(map);
|
| - MarkObject(map, map_mark);
|
| -
|
| - MarkCompactMarkingVisitor::IterateBody(map, object);
|
| - }
|
| -}
|
| -
|
| -
|
| -// Sweep the heap for overflowed objects, clear their overflow bits, and
|
| -// push them on the marking stack. Stop early if the marking stack fills
|
| -// before sweeping completes. If sweeping completes, there are no remaining
|
| -// overflowed objects in the heap so the overflow flag on the markings stack
|
| -// is cleared.
|
| -void MarkCompactCollector::RefillMarkingDeque() {
|
| - DCHECK(marking_deque_.overflowed());
|
| -
|
| - DiscoverGreyObjectsInNewSpace(heap(), &marking_deque_);
|
| - if (marking_deque_.IsFull()) return;
|
| -
|
| - DiscoverGreyObjectsInSpace(heap(),
|
| - &marking_deque_,
|
| - heap()->old_pointer_space());
|
| - if (marking_deque_.IsFull()) return;
|
| -
|
| - DiscoverGreyObjectsInSpace(heap(),
|
| - &marking_deque_,
|
| - heap()->old_data_space());
|
| - if (marking_deque_.IsFull()) return;
|
| -
|
| - DiscoverGreyObjectsInSpace(heap(),
|
| - &marking_deque_,
|
| - heap()->code_space());
|
| - if (marking_deque_.IsFull()) return;
|
| -
|
| - DiscoverGreyObjectsInSpace(heap(),
|
| - &marking_deque_,
|
| - heap()->map_space());
|
| - if (marking_deque_.IsFull()) return;
|
| -
|
| - DiscoverGreyObjectsInSpace(heap(),
|
| - &marking_deque_,
|
| - heap()->cell_space());
|
| - if (marking_deque_.IsFull()) return;
|
| -
|
| - DiscoverGreyObjectsInSpace(heap(),
|
| - &marking_deque_,
|
| - heap()->property_cell_space());
|
| - if (marking_deque_.IsFull()) return;
|
| -
|
| - LargeObjectIterator lo_it(heap()->lo_space());
|
| - DiscoverGreyObjectsWithIterator(heap(),
|
| - &marking_deque_,
|
| - &lo_it);
|
| - if (marking_deque_.IsFull()) return;
|
| -
|
| - marking_deque_.ClearOverflowed();
|
| -}
|
| -
|
| -
|
| -// Mark all objects reachable (transitively) from objects on the marking
|
| -// stack. Before: the marking stack contains zero or more heap object
|
| -// pointers. After: the marking stack is empty and there are no overflowed
|
| -// objects in the heap.
|
| -void MarkCompactCollector::ProcessMarkingDeque() {
|
| - EmptyMarkingDeque();
|
| - while (marking_deque_.overflowed()) {
|
| - RefillMarkingDeque();
|
| - EmptyMarkingDeque();
|
| - }
|
| -}
|
| -
|
| -
|
| -// Mark all objects reachable (transitively) from objects on the marking
|
| -// stack including references only considered in the atomic marking pause.
|
| -void MarkCompactCollector::ProcessEphemeralMarking(ObjectVisitor* visitor) {
|
| - bool work_to_do = true;
|
| - DCHECK(marking_deque_.IsEmpty());
|
| - while (work_to_do) {
|
| - isolate()->global_handles()->IterateObjectGroups(
|
| - visitor, &IsUnmarkedHeapObjectWithHeap);
|
| - MarkImplicitRefGroups();
|
| - ProcessWeakCollections();
|
| - work_to_do = !marking_deque_.IsEmpty();
|
| - ProcessMarkingDeque();
|
| - }
|
| -}
|
| -
|
| -
|
| -void MarkCompactCollector::ProcessTopOptimizedFrame(ObjectVisitor* visitor) {
|
| - for (StackFrameIterator it(isolate(), isolate()->thread_local_top());
|
| - !it.done(); it.Advance()) {
|
| - if (it.frame()->type() == StackFrame::JAVA_SCRIPT) {
|
| - return;
|
| - }
|
| - if (it.frame()->type() == StackFrame::OPTIMIZED) {
|
| - Code* code = it.frame()->LookupCode();
|
| - if (!code->CanDeoptAt(it.frame()->pc())) {
|
| - code->CodeIterateBody(visitor);
|
| - }
|
| - ProcessMarkingDeque();
|
| - return;
|
| - }
|
| - }
|
| -}
|
| -
|
| -
|
| -void MarkCompactCollector::MarkLiveObjects() {
|
| - GCTracer::Scope gc_scope(heap()->tracer(), GCTracer::Scope::MC_MARK);
|
| - double start_time = 0.0;
|
| - if (FLAG_print_cumulative_gc_stat) {
|
| - start_time = base::OS::TimeCurrentMillis();
|
| - }
|
| - // The recursive GC marker detects when it is nearing stack overflow,
|
| - // and switches to a different marking system. JS interrupts interfere
|
| - // with the C stack limit check.
|
| - PostponeInterruptsScope postpone(isolate());
|
| -
|
| - bool incremental_marking_overflowed = false;
|
| - IncrementalMarking* incremental_marking = heap_->incremental_marking();
|
| - if (was_marked_incrementally_) {
|
| - // Finalize the incremental marking and check whether we had an overflow.
|
| - // Both markers use grey color to mark overflowed objects so
|
| - // non-incremental marker can deal with them as if overflow
|
| - // occured during normal marking.
|
| - // But incremental marker uses a separate marking deque
|
| - // so we have to explicitly copy its overflow state.
|
| - incremental_marking->Finalize();
|
| - incremental_marking_overflowed =
|
| - incremental_marking->marking_deque()->overflowed();
|
| - incremental_marking->marking_deque()->ClearOverflowed();
|
| - } else {
|
| - // Abort any pending incremental activities e.g. incremental sweeping.
|
| - incremental_marking->Abort();
|
| - }
|
| -
|
| -#ifdef DEBUG
|
| - DCHECK(state_ == PREPARE_GC);
|
| - state_ = MARK_LIVE_OBJECTS;
|
| -#endif
|
| - // The to space contains live objects, a page in from space is used as a
|
| - // marking stack.
|
| - Address marking_deque_start = heap()->new_space()->FromSpacePageLow();
|
| - Address marking_deque_end = heap()->new_space()->FromSpacePageHigh();
|
| - if (FLAG_force_marking_deque_overflows) {
|
| - marking_deque_end = marking_deque_start + 64 * kPointerSize;
|
| - }
|
| - marking_deque_.Initialize(marking_deque_start,
|
| - marking_deque_end);
|
| - DCHECK(!marking_deque_.overflowed());
|
| -
|
| - if (incremental_marking_overflowed) {
|
| - // There are overflowed objects left in the heap after incremental marking.
|
| - marking_deque_.SetOverflowed();
|
| - }
|
| -
|
| - PrepareForCodeFlushing();
|
| -
|
| - if (was_marked_incrementally_) {
|
| - // There is no write barrier on cells so we have to scan them now at the end
|
| - // of the incremental marking.
|
| - {
|
| - HeapObjectIterator cell_iterator(heap()->cell_space());
|
| - HeapObject* cell;
|
| - while ((cell = cell_iterator.Next()) != NULL) {
|
| - DCHECK(cell->IsCell());
|
| - if (IsMarked(cell)) {
|
| - int offset = Cell::kValueOffset;
|
| - MarkCompactMarkingVisitor::VisitPointer(
|
| - heap(),
|
| - reinterpret_cast<Object**>(cell->address() + offset));
|
| - }
|
| - }
|
| - }
|
| - {
|
| - HeapObjectIterator js_global_property_cell_iterator(
|
| - heap()->property_cell_space());
|
| - HeapObject* cell;
|
| - while ((cell = js_global_property_cell_iterator.Next()) != NULL) {
|
| - DCHECK(cell->IsPropertyCell());
|
| - if (IsMarked(cell)) {
|
| - MarkCompactMarkingVisitor::VisitPropertyCell(cell->map(), cell);
|
| - }
|
| - }
|
| - }
|
| - }
|
| -
|
| - RootMarkingVisitor root_visitor(heap());
|
| - MarkRoots(&root_visitor);
|
| -
|
| - ProcessTopOptimizedFrame(&root_visitor);
|
| -
|
| - // The objects reachable from the roots are marked, yet unreachable
|
| - // objects are unmarked. Mark objects reachable due to host
|
| - // application specific logic or through Harmony weak maps.
|
| - ProcessEphemeralMarking(&root_visitor);
|
| -
|
| - // The objects reachable from the roots, weak maps or object groups
|
| - // are marked, yet unreachable objects are unmarked. Mark objects
|
| - // reachable only from weak global handles.
|
| - //
|
| - // First we identify nonlive weak handles and mark them as pending
|
| - // destruction.
|
| - heap()->isolate()->global_handles()->IdentifyWeakHandles(
|
| - &IsUnmarkedHeapObject);
|
| - // Then we mark the objects and process the transitive closure.
|
| - heap()->isolate()->global_handles()->IterateWeakRoots(&root_visitor);
|
| - while (marking_deque_.overflowed()) {
|
| - RefillMarkingDeque();
|
| - EmptyMarkingDeque();
|
| - }
|
| -
|
| - // Repeat host application specific and Harmony weak maps marking to
|
| - // mark unmarked objects reachable from the weak roots.
|
| - ProcessEphemeralMarking(&root_visitor);
|
| -
|
| - AfterMarking();
|
| -
|
| - if (FLAG_print_cumulative_gc_stat) {
|
| - heap_->tracer()->AddMarkingTime(base::OS::TimeCurrentMillis() - start_time);
|
| - }
|
| -}
|
| -
|
| -
|
| -void MarkCompactCollector::AfterMarking() {
|
| - // Object literal map caches reference strings (cache keys) and maps
|
| - // (cache values). At this point still useful maps have already been
|
| - // marked. Mark the keys for the alive values before we process the
|
| - // string table.
|
| - ProcessMapCaches();
|
| -
|
| - // Prune the string table removing all strings only pointed to by the
|
| - // string table. Cannot use string_table() here because the string
|
| - // table is marked.
|
| - StringTable* string_table = heap()->string_table();
|
| - InternalizedStringTableCleaner internalized_visitor(heap());
|
| - string_table->IterateElements(&internalized_visitor);
|
| - string_table->ElementsRemoved(internalized_visitor.PointersRemoved());
|
| -
|
| - ExternalStringTableCleaner external_visitor(heap());
|
| - heap()->external_string_table_.Iterate(&external_visitor);
|
| - heap()->external_string_table_.CleanUp();
|
| -
|
| - // Process the weak references.
|
| - MarkCompactWeakObjectRetainer mark_compact_object_retainer;
|
| - heap()->ProcessWeakReferences(&mark_compact_object_retainer);
|
| -
|
| - // Remove object groups after marking phase.
|
| - heap()->isolate()->global_handles()->RemoveObjectGroups();
|
| - heap()->isolate()->global_handles()->RemoveImplicitRefGroups();
|
| -
|
| - // Flush code from collected candidates.
|
| - if (is_code_flushing_enabled()) {
|
| - code_flusher_->ProcessCandidates();
|
| - // If incremental marker does not support code flushing, we need to
|
| - // disable it before incremental marking steps for next cycle.
|
| - if (FLAG_flush_code && !FLAG_flush_code_incrementally) {
|
| - EnableCodeFlushing(false);
|
| - }
|
| - }
|
| -
|
| - if (FLAG_track_gc_object_stats) {
|
| - heap()->CheckpointObjectStats();
|
| - }
|
| -}
|
| -
|
| -
|
| -void MarkCompactCollector::ProcessMapCaches() {
|
| - Object* raw_context = heap()->native_contexts_list();
|
| - while (raw_context != heap()->undefined_value()) {
|
| - Context* context = reinterpret_cast<Context*>(raw_context);
|
| - if (IsMarked(context)) {
|
| - HeapObject* raw_map_cache =
|
| - HeapObject::cast(context->get(Context::MAP_CACHE_INDEX));
|
| - // A map cache may be reachable from the stack. In this case
|
| - // it's already transitively marked and it's too late to clean
|
| - // up its parts.
|
| - if (!IsMarked(raw_map_cache) &&
|
| - raw_map_cache != heap()->undefined_value()) {
|
| - MapCache* map_cache = reinterpret_cast<MapCache*>(raw_map_cache);
|
| - int existing_elements = map_cache->NumberOfElements();
|
| - int used_elements = 0;
|
| - for (int i = MapCache::kElementsStartIndex;
|
| - i < map_cache->length();
|
| - i += MapCache::kEntrySize) {
|
| - Object* raw_key = map_cache->get(i);
|
| - if (raw_key == heap()->undefined_value() ||
|
| - raw_key == heap()->the_hole_value()) continue;
|
| - STATIC_ASSERT(MapCache::kEntrySize == 2);
|
| - Object* raw_map = map_cache->get(i + 1);
|
| - if (raw_map->IsHeapObject() && IsMarked(raw_map)) {
|
| - ++used_elements;
|
| - } else {
|
| - // Delete useless entries with unmarked maps.
|
| - DCHECK(raw_map->IsMap());
|
| - map_cache->set_the_hole(i);
|
| - map_cache->set_the_hole(i + 1);
|
| - }
|
| - }
|
| - if (used_elements == 0) {
|
| - context->set(Context::MAP_CACHE_INDEX, heap()->undefined_value());
|
| - } else {
|
| - // Note: we don't actually shrink the cache here to avoid
|
| - // extra complexity during GC. We rely on subsequent cache
|
| - // usages (EnsureCapacity) to do this.
|
| - map_cache->ElementsRemoved(existing_elements - used_elements);
|
| - MarkBit map_cache_markbit = Marking::MarkBitFrom(map_cache);
|
| - MarkObject(map_cache, map_cache_markbit);
|
| - }
|
| - }
|
| - }
|
| - // Move to next element in the list.
|
| - raw_context = context->get(Context::NEXT_CONTEXT_LINK);
|
| - }
|
| - ProcessMarkingDeque();
|
| -}
|
| -
|
| -
|
| -void MarkCompactCollector::ClearNonLiveReferences() {
|
| - // Iterate over the map space, setting map transitions that go from
|
| - // a marked map to an unmarked map to null transitions. This action
|
| - // is carried out only on maps of JSObjects and related subtypes.
|
| - HeapObjectIterator map_iterator(heap()->map_space());
|
| - for (HeapObject* obj = map_iterator.Next();
|
| - obj != NULL;
|
| - obj = map_iterator.Next()) {
|
| - Map* map = Map::cast(obj);
|
| -
|
| - if (!map->CanTransition()) continue;
|
| -
|
| - MarkBit map_mark = Marking::MarkBitFrom(map);
|
| - ClearNonLivePrototypeTransitions(map);
|
| - ClearNonLiveMapTransitions(map, map_mark);
|
| -
|
| - if (map_mark.Get()) {
|
| - ClearNonLiveDependentCode(map->dependent_code());
|
| - } else {
|
| - ClearDependentCode(map->dependent_code());
|
| - map->set_dependent_code(DependentCode::cast(heap()->empty_fixed_array()));
|
| - }
|
| - }
|
| -
|
| - // Iterate over property cell space, removing dependent code that is not
|
| - // otherwise kept alive by strong references.
|
| - HeapObjectIterator cell_iterator(heap_->property_cell_space());
|
| - for (HeapObject* cell = cell_iterator.Next();
|
| - cell != NULL;
|
| - cell = cell_iterator.Next()) {
|
| - if (IsMarked(cell)) {
|
| - ClearNonLiveDependentCode(PropertyCell::cast(cell)->dependent_code());
|
| - }
|
| - }
|
| -
|
| - // Iterate over allocation sites, removing dependent code that is not
|
| - // otherwise kept alive by strong references.
|
| - Object* undefined = heap()->undefined_value();
|
| - for (Object* site = heap()->allocation_sites_list();
|
| - site != undefined;
|
| - site = AllocationSite::cast(site)->weak_next()) {
|
| - if (IsMarked(site)) {
|
| - ClearNonLiveDependentCode(AllocationSite::cast(site)->dependent_code());
|
| - }
|
| - }
|
| -
|
| - if (heap_->weak_object_to_code_table()->IsHashTable()) {
|
| - WeakHashTable* table =
|
| - WeakHashTable::cast(heap_->weak_object_to_code_table());
|
| - uint32_t capacity = table->Capacity();
|
| - for (uint32_t i = 0; i < capacity; i++) {
|
| - uint32_t key_index = table->EntryToIndex(i);
|
| - Object* key = table->get(key_index);
|
| - if (!table->IsKey(key)) continue;
|
| - uint32_t value_index = table->EntryToValueIndex(i);
|
| - Object* value = table->get(value_index);
|
| - if (key->IsCell() && !IsMarked(key)) {
|
| - Cell* cell = Cell::cast(key);
|
| - Object* object = cell->value();
|
| - if (IsMarked(object)) {
|
| - MarkBit mark = Marking::MarkBitFrom(cell);
|
| - SetMark(cell, mark);
|
| - Object** value_slot = HeapObject::RawField(cell, Cell::kValueOffset);
|
| - RecordSlot(value_slot, value_slot, *value_slot);
|
| - }
|
| - }
|
| - if (IsMarked(key)) {
|
| - if (!IsMarked(value)) {
|
| - HeapObject* obj = HeapObject::cast(value);
|
| - MarkBit mark = Marking::MarkBitFrom(obj);
|
| - SetMark(obj, mark);
|
| - }
|
| - ClearNonLiveDependentCode(DependentCode::cast(value));
|
| - } else {
|
| - ClearDependentCode(DependentCode::cast(value));
|
| - table->set(key_index, heap_->the_hole_value());
|
| - table->set(value_index, heap_->the_hole_value());
|
| - table->ElementRemoved();
|
| - }
|
| - }
|
| - }
|
| -}
|
| -
|
| -
|
| -void MarkCompactCollector::ClearNonLivePrototypeTransitions(Map* map) {
|
| - int number_of_transitions = map->NumberOfProtoTransitions();
|
| - FixedArray* prototype_transitions = map->GetPrototypeTransitions();
|
| -
|
| - int new_number_of_transitions = 0;
|
| - const int header = Map::kProtoTransitionHeaderSize;
|
| - const int proto_offset = header + Map::kProtoTransitionPrototypeOffset;
|
| - const int map_offset = header + Map::kProtoTransitionMapOffset;
|
| - const int step = Map::kProtoTransitionElementsPerEntry;
|
| - for (int i = 0; i < number_of_transitions; i++) {
|
| - Object* prototype = prototype_transitions->get(proto_offset + i * step);
|
| - Object* cached_map = prototype_transitions->get(map_offset + i * step);
|
| - if (IsMarked(prototype) && IsMarked(cached_map)) {
|
| - DCHECK(!prototype->IsUndefined());
|
| - int proto_index = proto_offset + new_number_of_transitions * step;
|
| - int map_index = map_offset + new_number_of_transitions * step;
|
| - if (new_number_of_transitions != i) {
|
| - prototype_transitions->set(
|
| - proto_index,
|
| - prototype,
|
| - UPDATE_WRITE_BARRIER);
|
| - prototype_transitions->set(
|
| - map_index,
|
| - cached_map,
|
| - SKIP_WRITE_BARRIER);
|
| - }
|
| - Object** slot = prototype_transitions->RawFieldOfElementAt(proto_index);
|
| - RecordSlot(slot, slot, prototype);
|
| - new_number_of_transitions++;
|
| - }
|
| - }
|
| -
|
| - if (new_number_of_transitions != number_of_transitions) {
|
| - map->SetNumberOfProtoTransitions(new_number_of_transitions);
|
| - }
|
| -
|
| - // Fill slots that became free with undefined value.
|
| - for (int i = new_number_of_transitions * step;
|
| - i < number_of_transitions * step;
|
| - i++) {
|
| - prototype_transitions->set_undefined(header + i);
|
| - }
|
| -}
|
| -
|
| -
|
| -void MarkCompactCollector::ClearNonLiveMapTransitions(Map* map,
|
| - MarkBit map_mark) {
|
| - Object* potential_parent = map->GetBackPointer();
|
| - if (!potential_parent->IsMap()) return;
|
| - Map* parent = Map::cast(potential_parent);
|
| -
|
| - // Follow back pointer, check whether we are dealing with a map transition
|
| - // from a live map to a dead path and in case clear transitions of parent.
|
| - bool current_is_alive = map_mark.Get();
|
| - bool parent_is_alive = Marking::MarkBitFrom(parent).Get();
|
| - if (!current_is_alive && parent_is_alive) {
|
| - parent->ClearNonLiveTransitions(heap());
|
| - }
|
| -}
|
| -
|
| -
|
| -void MarkCompactCollector::ClearDependentICList(Object* head) {
|
| - Object* current = head;
|
| - Object* undefined = heap()->undefined_value();
|
| - while (current != undefined) {
|
| - Code* code = Code::cast(current);
|
| - if (IsMarked(code)) {
|
| - DCHECK(code->is_weak_stub());
|
| - IC::InvalidateMaps(code);
|
| - }
|
| - current = code->next_code_link();
|
| - code->set_next_code_link(undefined);
|
| - }
|
| -}
|
| -
|
| -
|
| -void MarkCompactCollector::ClearDependentCode(
|
| - DependentCode* entries) {
|
| - DisallowHeapAllocation no_allocation;
|
| - DependentCode::GroupStartIndexes starts(entries);
|
| - int number_of_entries = starts.number_of_entries();
|
| - if (number_of_entries == 0) return;
|
| - int g = DependentCode::kWeakICGroup;
|
| - if (starts.at(g) != starts.at(g + 1)) {
|
| - int i = starts.at(g);
|
| - DCHECK(i + 1 == starts.at(g + 1));
|
| - Object* head = entries->object_at(i);
|
| - ClearDependentICList(head);
|
| - }
|
| - g = DependentCode::kWeakCodeGroup;
|
| - for (int i = starts.at(g); i < starts.at(g + 1); i++) {
|
| - // If the entry is compilation info then the map must be alive,
|
| - // and ClearDependentCode shouldn't be called.
|
| - DCHECK(entries->is_code_at(i));
|
| - Code* code = entries->code_at(i);
|
| - if (IsMarked(code) && !code->marked_for_deoptimization()) {
|
| - code->set_marked_for_deoptimization(true);
|
| - code->InvalidateEmbeddedObjects();
|
| - have_code_to_deoptimize_ = true;
|
| - }
|
| - }
|
| - for (int i = 0; i < number_of_entries; i++) {
|
| - entries->clear_at(i);
|
| - }
|
| -}
|
| -
|
| -
|
| -int MarkCompactCollector::ClearNonLiveDependentCodeInGroup(
|
| - DependentCode* entries, int group, int start, int end, int new_start) {
|
| - int survived = 0;
|
| - if (group == DependentCode::kWeakICGroup) {
|
| - // Dependent weak IC stubs form a linked list and only the head is stored
|
| - // in the dependent code array.
|
| - if (start != end) {
|
| - DCHECK(start + 1 == end);
|
| - Object* old_head = entries->object_at(start);
|
| - MarkCompactWeakObjectRetainer retainer;
|
| - Object* head = VisitWeakList<Code>(heap(), old_head, &retainer);
|
| - entries->set_object_at(new_start, head);
|
| - Object** slot = entries->slot_at(new_start);
|
| - RecordSlot(slot, slot, head);
|
| - // We do not compact this group even if the head is undefined,
|
| - // more dependent ICs are likely to be added later.
|
| - survived = 1;
|
| - }
|
| - } else {
|
| - for (int i = start; i < end; i++) {
|
| - Object* obj = entries->object_at(i);
|
| - DCHECK(obj->IsCode() || IsMarked(obj));
|
| - if (IsMarked(obj) &&
|
| - (!obj->IsCode() || !WillBeDeoptimized(Code::cast(obj)))) {
|
| - if (new_start + survived != i) {
|
| - entries->set_object_at(new_start + survived, obj);
|
| - }
|
| - Object** slot = entries->slot_at(new_start + survived);
|
| - RecordSlot(slot, slot, obj);
|
| - survived++;
|
| - }
|
| - }
|
| - }
|
| - entries->set_number_of_entries(
|
| - static_cast<DependentCode::DependencyGroup>(group), survived);
|
| - return survived;
|
| -}
|
| -
|
| -
|
| -void MarkCompactCollector::ClearNonLiveDependentCode(DependentCode* entries) {
|
| - DisallowHeapAllocation no_allocation;
|
| - DependentCode::GroupStartIndexes starts(entries);
|
| - int number_of_entries = starts.number_of_entries();
|
| - if (number_of_entries == 0) return;
|
| - int new_number_of_entries = 0;
|
| - // Go through all groups, remove dead codes and compact.
|
| - for (int g = 0; g < DependentCode::kGroupCount; g++) {
|
| - int survived = ClearNonLiveDependentCodeInGroup(
|
| - entries, g, starts.at(g), starts.at(g + 1), new_number_of_entries);
|
| - new_number_of_entries += survived;
|
| - }
|
| - for (int i = new_number_of_entries; i < number_of_entries; i++) {
|
| - entries->clear_at(i);
|
| - }
|
| -}
|
| -
|
| -
|
| -void MarkCompactCollector::ProcessWeakCollections() {
|
| - GCTracer::Scope gc_scope(heap()->tracer(),
|
| - GCTracer::Scope::MC_WEAKCOLLECTION_PROCESS);
|
| - Object* weak_collection_obj = heap()->encountered_weak_collections();
|
| - while (weak_collection_obj != Smi::FromInt(0)) {
|
| - JSWeakCollection* weak_collection =
|
| - reinterpret_cast<JSWeakCollection*>(weak_collection_obj);
|
| - DCHECK(MarkCompactCollector::IsMarked(weak_collection));
|
| - if (weak_collection->table()->IsHashTable()) {
|
| - ObjectHashTable* table = ObjectHashTable::cast(weak_collection->table());
|
| - Object** anchor = reinterpret_cast<Object**>(table->address());
|
| - for (int i = 0; i < table->Capacity(); i++) {
|
| - if (MarkCompactCollector::IsMarked(HeapObject::cast(table->KeyAt(i)))) {
|
| - Object** key_slot =
|
| - table->RawFieldOfElementAt(ObjectHashTable::EntryToIndex(i));
|
| - RecordSlot(anchor, key_slot, *key_slot);
|
| - Object** value_slot =
|
| - table->RawFieldOfElementAt(ObjectHashTable::EntryToValueIndex(i));
|
| - MarkCompactMarkingVisitor::MarkObjectByPointer(
|
| - this, anchor, value_slot);
|
| - }
|
| - }
|
| - }
|
| - weak_collection_obj = weak_collection->next();
|
| - }
|
| -}
|
| -
|
| -
|
| -void MarkCompactCollector::ClearWeakCollections() {
|
| - GCTracer::Scope gc_scope(heap()->tracer(),
|
| - GCTracer::Scope::MC_WEAKCOLLECTION_CLEAR);
|
| - Object* weak_collection_obj = heap()->encountered_weak_collections();
|
| - while (weak_collection_obj != Smi::FromInt(0)) {
|
| - JSWeakCollection* weak_collection =
|
| - reinterpret_cast<JSWeakCollection*>(weak_collection_obj);
|
| - DCHECK(MarkCompactCollector::IsMarked(weak_collection));
|
| - if (weak_collection->table()->IsHashTable()) {
|
| - ObjectHashTable* table = ObjectHashTable::cast(weak_collection->table());
|
| - for (int i = 0; i < table->Capacity(); i++) {
|
| - HeapObject* key = HeapObject::cast(table->KeyAt(i));
|
| - if (!MarkCompactCollector::IsMarked(key)) {
|
| - table->RemoveEntry(i);
|
| - }
|
| - }
|
| - }
|
| - weak_collection_obj = weak_collection->next();
|
| - weak_collection->set_next(heap()->undefined_value());
|
| - }
|
| - heap()->set_encountered_weak_collections(Smi::FromInt(0));
|
| -}
|
| -
|
| -
|
| -void MarkCompactCollector::RecordMigratedSlot(Object* value, Address slot) {
|
| - if (heap_->InNewSpace(value)) {
|
| - heap_->store_buffer()->Mark(slot);
|
| - } else if (value->IsHeapObject() && IsOnEvacuationCandidate(value)) {
|
| - SlotsBuffer::AddTo(&slots_buffer_allocator_,
|
| - &migration_slots_buffer_,
|
| - reinterpret_cast<Object**>(slot),
|
| - SlotsBuffer::IGNORE_OVERFLOW);
|
| - }
|
| -}
|
| -
|
| -
|
| -
|
| -// We scavange new space simultaneously with sweeping. This is done in two
|
| -// passes.
|
| -//
|
| -// The first pass migrates all alive objects from one semispace to another or
|
| -// promotes them to old space. Forwarding address is written directly into
|
| -// first word of object without any encoding. If object is dead we write
|
| -// NULL as a forwarding address.
|
| -//
|
| -// The second pass updates pointers to new space in all spaces. It is possible
|
| -// to encounter pointers to dead new space objects during traversal of pointers
|
| -// to new space. We should clear them to avoid encountering them during next
|
| -// pointer iteration. This is an issue if the store buffer overflows and we
|
| -// have to scan the entire old space, including dead objects, looking for
|
| -// pointers to new space.
|
| -void MarkCompactCollector::MigrateObject(HeapObject* dst,
|
| - HeapObject* src,
|
| - int size,
|
| - AllocationSpace dest) {
|
| - Address dst_addr = dst->address();
|
| - Address src_addr = src->address();
|
| - DCHECK(heap()->AllowedToBeMigrated(src, dest));
|
| - DCHECK(dest != LO_SPACE && size <= Page::kMaxRegularHeapObjectSize);
|
| - if (dest == OLD_POINTER_SPACE) {
|
| - Address src_slot = src_addr;
|
| - Address dst_slot = dst_addr;
|
| - DCHECK(IsAligned(size, kPointerSize));
|
| -
|
| - for (int remaining = size / kPointerSize; remaining > 0; remaining--) {
|
| - Object* value = Memory::Object_at(src_slot);
|
| -
|
| - Memory::Object_at(dst_slot) = value;
|
| -
|
| - // We special case ConstantPoolArrays below since they could contain
|
| - // integers value entries which look like tagged pointers.
|
| - // TODO(mstarzinger): restructure this code to avoid this special-casing.
|
| - if (!src->IsConstantPoolArray()) {
|
| - RecordMigratedSlot(value, dst_slot);
|
| - }
|
| -
|
| - src_slot += kPointerSize;
|
| - dst_slot += kPointerSize;
|
| - }
|
| -
|
| - if (compacting_ && dst->IsJSFunction()) {
|
| - Address code_entry_slot = dst_addr + JSFunction::kCodeEntryOffset;
|
| - Address code_entry = Memory::Address_at(code_entry_slot);
|
| -
|
| - if (Page::FromAddress(code_entry)->IsEvacuationCandidate()) {
|
| - SlotsBuffer::AddTo(&slots_buffer_allocator_,
|
| - &migration_slots_buffer_,
|
| - SlotsBuffer::CODE_ENTRY_SLOT,
|
| - code_entry_slot,
|
| - SlotsBuffer::IGNORE_OVERFLOW);
|
| - }
|
| - } else if (dst->IsConstantPoolArray()) {
|
| - ConstantPoolArray* array = ConstantPoolArray::cast(dst);
|
| - ConstantPoolArray::Iterator code_iter(array, ConstantPoolArray::CODE_PTR);
|
| - while (!code_iter.is_finished()) {
|
| - Address code_entry_slot =
|
| - dst_addr + array->OffsetOfElementAt(code_iter.next_index());
|
| - Address code_entry = Memory::Address_at(code_entry_slot);
|
| -
|
| - if (Page::FromAddress(code_entry)->IsEvacuationCandidate()) {
|
| - SlotsBuffer::AddTo(&slots_buffer_allocator_,
|
| - &migration_slots_buffer_,
|
| - SlotsBuffer::CODE_ENTRY_SLOT,
|
| - code_entry_slot,
|
| - SlotsBuffer::IGNORE_OVERFLOW);
|
| - }
|
| - }
|
| - ConstantPoolArray::Iterator heap_iter(array, ConstantPoolArray::HEAP_PTR);
|
| - while (!heap_iter.is_finished()) {
|
| - Address heap_slot =
|
| - dst_addr + array->OffsetOfElementAt(heap_iter.next_index());
|
| - Object* value = Memory::Object_at(heap_slot);
|
| - RecordMigratedSlot(value, heap_slot);
|
| - }
|
| - }
|
| - } else if (dest == CODE_SPACE) {
|
| - PROFILE(isolate(), CodeMoveEvent(src_addr, dst_addr));
|
| - heap()->MoveBlock(dst_addr, src_addr, size);
|
| - SlotsBuffer::AddTo(&slots_buffer_allocator_,
|
| - &migration_slots_buffer_,
|
| - SlotsBuffer::RELOCATED_CODE_OBJECT,
|
| - dst_addr,
|
| - SlotsBuffer::IGNORE_OVERFLOW);
|
| - Code::cast(dst)->Relocate(dst_addr - src_addr);
|
| - } else {
|
| - DCHECK(dest == OLD_DATA_SPACE || dest == NEW_SPACE);
|
| - heap()->MoveBlock(dst_addr, src_addr, size);
|
| - }
|
| - heap()->OnMoveEvent(dst, src, size);
|
| - Memory::Address_at(src_addr) = dst_addr;
|
| -}
|
| -
|
| -
|
| -// Visitor for updating pointers from live objects in old spaces to new space.
|
| -// It does not expect to encounter pointers to dead objects.
|
| -class PointersUpdatingVisitor: public ObjectVisitor {
|
| - public:
|
| - explicit PointersUpdatingVisitor(Heap* heap) : heap_(heap) { }
|
| -
|
| - void VisitPointer(Object** p) {
|
| - UpdatePointer(p);
|
| - }
|
| -
|
| - void VisitPointers(Object** start, Object** end) {
|
| - for (Object** p = start; p < end; p++) UpdatePointer(p);
|
| - }
|
| -
|
| - void VisitEmbeddedPointer(RelocInfo* rinfo) {
|
| - DCHECK(rinfo->rmode() == RelocInfo::EMBEDDED_OBJECT);
|
| - Object* target = rinfo->target_object();
|
| - Object* old_target = target;
|
| - VisitPointer(&target);
|
| - // Avoid unnecessary changes that might unnecessary flush the instruction
|
| - // cache.
|
| - if (target != old_target) {
|
| - rinfo->set_target_object(target);
|
| - }
|
| - }
|
| -
|
| - void VisitCodeTarget(RelocInfo* rinfo) {
|
| - DCHECK(RelocInfo::IsCodeTarget(rinfo->rmode()));
|
| - Object* target = Code::GetCodeFromTargetAddress(rinfo->target_address());
|
| - Object* old_target = target;
|
| - VisitPointer(&target);
|
| - if (target != old_target) {
|
| - rinfo->set_target_address(Code::cast(target)->instruction_start());
|
| - }
|
| - }
|
| -
|
| - void VisitCodeAgeSequence(RelocInfo* rinfo) {
|
| - DCHECK(RelocInfo::IsCodeAgeSequence(rinfo->rmode()));
|
| - Object* stub = rinfo->code_age_stub();
|
| - DCHECK(stub != NULL);
|
| - VisitPointer(&stub);
|
| - if (stub != rinfo->code_age_stub()) {
|
| - rinfo->set_code_age_stub(Code::cast(stub));
|
| - }
|
| - }
|
| -
|
| - void VisitDebugTarget(RelocInfo* rinfo) {
|
| - DCHECK((RelocInfo::IsJSReturn(rinfo->rmode()) &&
|
| - rinfo->IsPatchedReturnSequence()) ||
|
| - (RelocInfo::IsDebugBreakSlot(rinfo->rmode()) &&
|
| - rinfo->IsPatchedDebugBreakSlotSequence()));
|
| - Object* target = Code::GetCodeFromTargetAddress(rinfo->call_address());
|
| - VisitPointer(&target);
|
| - rinfo->set_call_address(Code::cast(target)->instruction_start());
|
| - }
|
| -
|
| - static inline void UpdateSlot(Heap* heap, Object** slot) {
|
| - Object* obj = *slot;
|
| -
|
| - if (!obj->IsHeapObject()) return;
|
| -
|
| - HeapObject* heap_obj = HeapObject::cast(obj);
|
| -
|
| - MapWord map_word = heap_obj->map_word();
|
| - if (map_word.IsForwardingAddress()) {
|
| - DCHECK(heap->InFromSpace(heap_obj) ||
|
| - MarkCompactCollector::IsOnEvacuationCandidate(heap_obj));
|
| - HeapObject* target = map_word.ToForwardingAddress();
|
| - *slot = target;
|
| - DCHECK(!heap->InFromSpace(target) &&
|
| - !MarkCompactCollector::IsOnEvacuationCandidate(target));
|
| - }
|
| - }
|
| -
|
| - private:
|
| - inline void UpdatePointer(Object** p) {
|
| - UpdateSlot(heap_, p);
|
| - }
|
| -
|
| - Heap* heap_;
|
| -};
|
| -
|
| -
|
| -static void UpdatePointer(HeapObject** address, HeapObject* object) {
|
| - Address new_addr = Memory::Address_at(object->address());
|
| -
|
| - // The new space sweep will overwrite the map word of dead objects
|
| - // with NULL. In this case we do not need to transfer this entry to
|
| - // the store buffer which we are rebuilding.
|
| - // We perform the pointer update with a no barrier compare-and-swap. The
|
| - // compare and swap may fail in the case where the pointer update tries to
|
| - // update garbage memory which was concurrently accessed by the sweeper.
|
| - if (new_addr != NULL) {
|
| - base::NoBarrier_CompareAndSwap(
|
| - reinterpret_cast<base::AtomicWord*>(address),
|
| - reinterpret_cast<base::AtomicWord>(object),
|
| - reinterpret_cast<base::AtomicWord>(HeapObject::FromAddress(new_addr)));
|
| - } else {
|
| - // We have to zap this pointer, because the store buffer may overflow later,
|
| - // and then we have to scan the entire heap and we don't want to find
|
| - // spurious newspace pointers in the old space.
|
| - // TODO(mstarzinger): This was changed to a sentinel value to track down
|
| - // rare crashes, change it back to Smi::FromInt(0) later.
|
| - base::NoBarrier_CompareAndSwap(
|
| - reinterpret_cast<base::AtomicWord*>(address),
|
| - reinterpret_cast<base::AtomicWord>(object),
|
| - reinterpret_cast<base::AtomicWord>(Smi::FromInt(0x0f100d00 >> 1)));
|
| - }
|
| -}
|
| -
|
| -
|
| -static String* UpdateReferenceInExternalStringTableEntry(Heap* heap,
|
| - Object** p) {
|
| - MapWord map_word = HeapObject::cast(*p)->map_word();
|
| -
|
| - if (map_word.IsForwardingAddress()) {
|
| - return String::cast(map_word.ToForwardingAddress());
|
| - }
|
| -
|
| - return String::cast(*p);
|
| -}
|
| -
|
| -
|
| -bool MarkCompactCollector::TryPromoteObject(HeapObject* object,
|
| - int object_size) {
|
| - DCHECK(object_size <= Page::kMaxRegularHeapObjectSize);
|
| -
|
| - OldSpace* target_space = heap()->TargetSpace(object);
|
| -
|
| - DCHECK(target_space == heap()->old_pointer_space() ||
|
| - target_space == heap()->old_data_space());
|
| - HeapObject* target;
|
| - AllocationResult allocation = target_space->AllocateRaw(object_size);
|
| - if (allocation.To(&target)) {
|
| - MigrateObject(target,
|
| - object,
|
| - object_size,
|
| - target_space->identity());
|
| - heap()->IncrementPromotedObjectsSize(object_size);
|
| - return true;
|
| - }
|
| -
|
| - return false;
|
| -}
|
| -
|
| -
|
| -void MarkCompactCollector::EvacuateNewSpace() {
|
| - // There are soft limits in the allocation code, designed trigger a mark
|
| - // sweep collection by failing allocations. But since we are already in
|
| - // a mark-sweep allocation, there is no sense in trying to trigger one.
|
| - AlwaysAllocateScope scope(isolate());
|
| -
|
| - NewSpace* new_space = heap()->new_space();
|
| -
|
| - // Store allocation range before flipping semispaces.
|
| - Address from_bottom = new_space->bottom();
|
| - Address from_top = new_space->top();
|
| -
|
| - // Flip the semispaces. After flipping, to space is empty, from space has
|
| - // live objects.
|
| - new_space->Flip();
|
| - new_space->ResetAllocationInfo();
|
| -
|
| - int survivors_size = 0;
|
| -
|
| - // First pass: traverse all objects in inactive semispace, remove marks,
|
| - // migrate live objects and write forwarding addresses. This stage puts
|
| - // new entries in the store buffer and may cause some pages to be marked
|
| - // scan-on-scavenge.
|
| - NewSpacePageIterator it(from_bottom, from_top);
|
| - while (it.has_next()) {
|
| - NewSpacePage* p = it.next();
|
| - survivors_size += DiscoverAndEvacuateBlackObjectsOnPage(new_space, p);
|
| - }
|
| -
|
| - heap_->IncrementYoungSurvivorsCounter(survivors_size);
|
| - new_space->set_age_mark(new_space->top());
|
| -}
|
| -
|
| -
|
| -void MarkCompactCollector::EvacuateLiveObjectsFromPage(Page* p) {
|
| - AlwaysAllocateScope always_allocate(isolate());
|
| - PagedSpace* space = static_cast<PagedSpace*>(p->owner());
|
| - DCHECK(p->IsEvacuationCandidate() && !p->WasSwept());
|
| - p->MarkSweptPrecisely();
|
| -
|
| - int offsets[16];
|
| -
|
| - for (MarkBitCellIterator it(p); !it.Done(); it.Advance()) {
|
| - Address cell_base = it.CurrentCellBase();
|
| - MarkBit::CellType* cell = it.CurrentCell();
|
| -
|
| - if (*cell == 0) continue;
|
| -
|
| - int live_objects = MarkWordToObjectStarts(*cell, offsets);
|
| - for (int i = 0; i < live_objects; i++) {
|
| - Address object_addr = cell_base + offsets[i] * kPointerSize;
|
| - HeapObject* object = HeapObject::FromAddress(object_addr);
|
| - DCHECK(Marking::IsBlack(Marking::MarkBitFrom(object)));
|
| -
|
| - int size = object->Size();
|
| -
|
| - HeapObject* target_object;
|
| - AllocationResult allocation = space->AllocateRaw(size);
|
| - if (!allocation.To(&target_object)) {
|
| - // If allocation failed, use emergency memory and re-try allocation.
|
| - CHECK(space->HasEmergencyMemory());
|
| - space->UseEmergencyMemory();
|
| - allocation = space->AllocateRaw(size);
|
| - }
|
| - if (!allocation.To(&target_object)) {
|
| - // OS refused to give us memory.
|
| - V8::FatalProcessOutOfMemory("Evacuation");
|
| - return;
|
| - }
|
| -
|
| - MigrateObject(target_object, object, size, space->identity());
|
| - DCHECK(object->map_word().IsForwardingAddress());
|
| - }
|
| -
|
| - // Clear marking bits for current cell.
|
| - *cell = 0;
|
| - }
|
| - p->ResetLiveBytes();
|
| -}
|
| -
|
| -
|
| -void MarkCompactCollector::EvacuatePages() {
|
| - int npages = evacuation_candidates_.length();
|
| - for (int i = 0; i < npages; i++) {
|
| - Page* p = evacuation_candidates_[i];
|
| - DCHECK(p->IsEvacuationCandidate() ||
|
| - p->IsFlagSet(Page::RESCAN_ON_EVACUATION));
|
| - DCHECK(static_cast<int>(p->parallel_sweeping()) ==
|
| - MemoryChunk::SWEEPING_DONE);
|
| - PagedSpace* space = static_cast<PagedSpace*>(p->owner());
|
| - // Allocate emergency memory for the case when compaction fails due to out
|
| - // of memory.
|
| - if (!space->HasEmergencyMemory()) {
|
| - space->CreateEmergencyMemory();
|
| - }
|
| - if (p->IsEvacuationCandidate()) {
|
| - // During compaction we might have to request a new page. Check that we
|
| - // have an emergency page and the space still has room for that.
|
| - if (space->HasEmergencyMemory() && space->CanExpand()) {
|
| - EvacuateLiveObjectsFromPage(p);
|
| - } else {
|
| - // Without room for expansion evacuation is not guaranteed to succeed.
|
| - // Pessimistically abandon unevacuated pages.
|
| - for (int j = i; j < npages; j++) {
|
| - Page* page = evacuation_candidates_[j];
|
| - slots_buffer_allocator_.DeallocateChain(page->slots_buffer_address());
|
| - page->ClearEvacuationCandidate();
|
| - page->SetFlag(Page::RESCAN_ON_EVACUATION);
|
| - }
|
| - break;
|
| - }
|
| - }
|
| - }
|
| - if (npages > 0) {
|
| - // Release emergency memory.
|
| - PagedSpaces spaces(heap());
|
| - for (PagedSpace* space = spaces.next(); space != NULL;
|
| - space = spaces.next()) {
|
| - if (space->HasEmergencyMemory()) {
|
| - space->FreeEmergencyMemory();
|
| - }
|
| - }
|
| - }
|
| -}
|
| -
|
| -
|
| -class EvacuationWeakObjectRetainer : public WeakObjectRetainer {
|
| - public:
|
| - virtual Object* RetainAs(Object* object) {
|
| - if (object->IsHeapObject()) {
|
| - HeapObject* heap_object = HeapObject::cast(object);
|
| - MapWord map_word = heap_object->map_word();
|
| - if (map_word.IsForwardingAddress()) {
|
| - return map_word.ToForwardingAddress();
|
| - }
|
| - }
|
| - return object;
|
| - }
|
| -};
|
| -
|
| -
|
| -static inline void UpdateSlot(Isolate* isolate,
|
| - ObjectVisitor* v,
|
| - SlotsBuffer::SlotType slot_type,
|
| - Address addr) {
|
| - switch (slot_type) {
|
| - case SlotsBuffer::CODE_TARGET_SLOT: {
|
| - RelocInfo rinfo(addr, RelocInfo::CODE_TARGET, 0, NULL);
|
| - rinfo.Visit(isolate, v);
|
| - break;
|
| - }
|
| - case SlotsBuffer::CODE_ENTRY_SLOT: {
|
| - v->VisitCodeEntry(addr);
|
| - break;
|
| - }
|
| - case SlotsBuffer::RELOCATED_CODE_OBJECT: {
|
| - HeapObject* obj = HeapObject::FromAddress(addr);
|
| - Code::cast(obj)->CodeIterateBody(v);
|
| - break;
|
| - }
|
| - case SlotsBuffer::DEBUG_TARGET_SLOT: {
|
| - RelocInfo rinfo(addr, RelocInfo::DEBUG_BREAK_SLOT, 0, NULL);
|
| - if (rinfo.IsPatchedDebugBreakSlotSequence()) rinfo.Visit(isolate, v);
|
| - break;
|
| - }
|
| - case SlotsBuffer::JS_RETURN_SLOT: {
|
| - RelocInfo rinfo(addr, RelocInfo::JS_RETURN, 0, NULL);
|
| - if (rinfo.IsPatchedReturnSequence()) rinfo.Visit(isolate, v);
|
| - break;
|
| - }
|
| - case SlotsBuffer::EMBEDDED_OBJECT_SLOT: {
|
| - RelocInfo rinfo(addr, RelocInfo::EMBEDDED_OBJECT, 0, NULL);
|
| - rinfo.Visit(isolate, v);
|
| - break;
|
| - }
|
| - default:
|
| - UNREACHABLE();
|
| - break;
|
| - }
|
| -}
|
| -
|
| -
|
| -enum SweepingMode {
|
| - SWEEP_ONLY,
|
| - SWEEP_AND_VISIT_LIVE_OBJECTS
|
| -};
|
| -
|
| -
|
| -enum SkipListRebuildingMode {
|
| - REBUILD_SKIP_LIST,
|
| - IGNORE_SKIP_LIST
|
| -};
|
| -
|
| -
|
| -enum FreeSpaceTreatmentMode {
|
| - IGNORE_FREE_SPACE,
|
| - ZAP_FREE_SPACE
|
| -};
|
| -
|
| -
|
| -template<MarkCompactCollector::SweepingParallelism mode>
|
| -static intptr_t Free(PagedSpace* space,
|
| - FreeList* free_list,
|
| - Address start,
|
| - int size) {
|
| - if (mode == MarkCompactCollector::SWEEP_ON_MAIN_THREAD) {
|
| - DCHECK(free_list == NULL);
|
| - return space->Free(start, size);
|
| - } else {
|
| - // TODO(hpayer): account for wasted bytes in concurrent sweeping too.
|
| - return size - free_list->Free(start, size);
|
| - }
|
| -}
|
| -
|
| -
|
| -// Sweep a space precisely. After this has been done the space can
|
| -// be iterated precisely, hitting only the live objects. Code space
|
| -// is always swept precisely because we want to be able to iterate
|
| -// over it. Map space is swept precisely, because it is not compacted.
|
| -// Slots in live objects pointing into evacuation candidates are updated
|
| -// if requested.
|
| -// Returns the size of the biggest continuous freed memory chunk in bytes.
|
| -template<SweepingMode sweeping_mode,
|
| - MarkCompactCollector::SweepingParallelism parallelism,
|
| - SkipListRebuildingMode skip_list_mode,
|
| - FreeSpaceTreatmentMode free_space_mode>
|
| -static int SweepPrecisely(PagedSpace* space,
|
| - FreeList* free_list,
|
| - Page* p,
|
| - ObjectVisitor* v) {
|
| - DCHECK(!p->IsEvacuationCandidate() && !p->WasSwept());
|
| - DCHECK_EQ(skip_list_mode == REBUILD_SKIP_LIST,
|
| - space->identity() == CODE_SPACE);
|
| - DCHECK((p->skip_list() == NULL) || (skip_list_mode == REBUILD_SKIP_LIST));
|
| - DCHECK(parallelism == MarkCompactCollector::SWEEP_ON_MAIN_THREAD ||
|
| - sweeping_mode == SWEEP_ONLY);
|
| -
|
| - Address free_start = p->area_start();
|
| - DCHECK(reinterpret_cast<intptr_t>(free_start) % (32 * kPointerSize) == 0);
|
| - int offsets[16];
|
| -
|
| - SkipList* skip_list = p->skip_list();
|
| - int curr_region = -1;
|
| - if ((skip_list_mode == REBUILD_SKIP_LIST) && skip_list) {
|
| - skip_list->Clear();
|
| - }
|
| -
|
| - intptr_t freed_bytes = 0;
|
| - intptr_t max_freed_bytes = 0;
|
| -
|
| - for (MarkBitCellIterator it(p); !it.Done(); it.Advance()) {
|
| - Address cell_base = it.CurrentCellBase();
|
| - MarkBit::CellType* cell = it.CurrentCell();
|
| - int live_objects = MarkWordToObjectStarts(*cell, offsets);
|
| - int live_index = 0;
|
| - for ( ; live_objects != 0; live_objects--) {
|
| - Address free_end = cell_base + offsets[live_index++] * kPointerSize;
|
| - if (free_end != free_start) {
|
| - int size = static_cast<int>(free_end - free_start);
|
| - if (free_space_mode == ZAP_FREE_SPACE) {
|
| - memset(free_start, 0xcc, size);
|
| - }
|
| - freed_bytes = Free<parallelism>(space, free_list, free_start, size);
|
| - max_freed_bytes = Max(freed_bytes, max_freed_bytes);
|
| -#ifdef ENABLE_GDB_JIT_INTERFACE
|
| - if (FLAG_gdbjit && space->identity() == CODE_SPACE) {
|
| - GDBJITInterface::RemoveCodeRange(free_start, free_end);
|
| - }
|
| -#endif
|
| - }
|
| - HeapObject* live_object = HeapObject::FromAddress(free_end);
|
| - DCHECK(Marking::IsBlack(Marking::MarkBitFrom(live_object)));
|
| - Map* map = live_object->map();
|
| - int size = live_object->SizeFromMap(map);
|
| - if (sweeping_mode == SWEEP_AND_VISIT_LIVE_OBJECTS) {
|
| - live_object->IterateBody(map->instance_type(), size, v);
|
| - }
|
| - if ((skip_list_mode == REBUILD_SKIP_LIST) && skip_list != NULL) {
|
| - int new_region_start =
|
| - SkipList::RegionNumber(free_end);
|
| - int new_region_end =
|
| - SkipList::RegionNumber(free_end + size - kPointerSize);
|
| - if (new_region_start != curr_region ||
|
| - new_region_end != curr_region) {
|
| - skip_list->AddObject(free_end, size);
|
| - curr_region = new_region_end;
|
| - }
|
| - }
|
| - free_start = free_end + size;
|
| - }
|
| - // Clear marking bits for current cell.
|
| - *cell = 0;
|
| - }
|
| - if (free_start != p->area_end()) {
|
| - int size = static_cast<int>(p->area_end() - free_start);
|
| - if (free_space_mode == ZAP_FREE_SPACE) {
|
| - memset(free_start, 0xcc, size);
|
| - }
|
| - freed_bytes = Free<parallelism>(space, free_list, free_start, size);
|
| - max_freed_bytes = Max(freed_bytes, max_freed_bytes);
|
| -#ifdef ENABLE_GDB_JIT_INTERFACE
|
| - if (FLAG_gdbjit && space->identity() == CODE_SPACE) {
|
| - GDBJITInterface::RemoveCodeRange(free_start, p->area_end());
|
| - }
|
| -#endif
|
| - }
|
| - p->ResetLiveBytes();
|
| -
|
| - if (parallelism == MarkCompactCollector::SWEEP_IN_PARALLEL) {
|
| - // When concurrent sweeping is active, the page will be marked after
|
| - // sweeping by the main thread.
|
| - p->set_parallel_sweeping(MemoryChunk::SWEEPING_FINALIZE);
|
| - } else {
|
| - p->MarkSweptPrecisely();
|
| - }
|
| - return FreeList::GuaranteedAllocatable(static_cast<int>(max_freed_bytes));
|
| -}
|
| -
|
| -
|
| -static bool SetMarkBitsUnderInvalidatedCode(Code* code, bool value) {
|
| - Page* p = Page::FromAddress(code->address());
|
| -
|
| - if (p->IsEvacuationCandidate() ||
|
| - p->IsFlagSet(Page::RESCAN_ON_EVACUATION)) {
|
| - return false;
|
| - }
|
| -
|
| - Address code_start = code->address();
|
| - Address code_end = code_start + code->Size();
|
| -
|
| - uint32_t start_index = MemoryChunk::FastAddressToMarkbitIndex(code_start);
|
| - uint32_t end_index =
|
| - MemoryChunk::FastAddressToMarkbitIndex(code_end - kPointerSize);
|
| -
|
| - Bitmap* b = p->markbits();
|
| -
|
| - MarkBit start_mark_bit = b->MarkBitFromIndex(start_index);
|
| - MarkBit end_mark_bit = b->MarkBitFromIndex(end_index);
|
| -
|
| - MarkBit::CellType* start_cell = start_mark_bit.cell();
|
| - MarkBit::CellType* end_cell = end_mark_bit.cell();
|
| -
|
| - if (value) {
|
| - MarkBit::CellType start_mask = ~(start_mark_bit.mask() - 1);
|
| - MarkBit::CellType end_mask = (end_mark_bit.mask() << 1) - 1;
|
| -
|
| - if (start_cell == end_cell) {
|
| - *start_cell |= start_mask & end_mask;
|
| - } else {
|
| - *start_cell |= start_mask;
|
| - for (MarkBit::CellType* cell = start_cell + 1; cell < end_cell; cell++) {
|
| - *cell = ~0;
|
| - }
|
| - *end_cell |= end_mask;
|
| - }
|
| - } else {
|
| - for (MarkBit::CellType* cell = start_cell ; cell <= end_cell; cell++) {
|
| - *cell = 0;
|
| - }
|
| - }
|
| -
|
| - return true;
|
| -}
|
| -
|
| -
|
| -static bool IsOnInvalidatedCodeObject(Address addr) {
|
| - // We did not record any slots in large objects thus
|
| - // we can safely go to the page from the slot address.
|
| - Page* p = Page::FromAddress(addr);
|
| -
|
| - // First check owner's identity because old pointer and old data spaces
|
| - // are swept lazily and might still have non-zero mark-bits on some
|
| - // pages.
|
| - if (p->owner()->identity() != CODE_SPACE) return false;
|
| -
|
| - // In code space only bits on evacuation candidates (but we don't record
|
| - // any slots on them) and under invalidated code objects are non-zero.
|
| - MarkBit mark_bit =
|
| - p->markbits()->MarkBitFromIndex(Page::FastAddressToMarkbitIndex(addr));
|
| -
|
| - return mark_bit.Get();
|
| -}
|
| -
|
| -
|
| -void MarkCompactCollector::InvalidateCode(Code* code) {
|
| - if (heap_->incremental_marking()->IsCompacting() &&
|
| - !ShouldSkipEvacuationSlotRecording(code)) {
|
| - DCHECK(compacting_);
|
| -
|
| - // If the object is white than no slots were recorded on it yet.
|
| - MarkBit mark_bit = Marking::MarkBitFrom(code);
|
| - if (Marking::IsWhite(mark_bit)) return;
|
| -
|
| - invalidated_code_.Add(code);
|
| - }
|
| -}
|
| -
|
| -
|
| -// Return true if the given code is deoptimized or will be deoptimized.
|
| -bool MarkCompactCollector::WillBeDeoptimized(Code* code) {
|
| - return code->is_optimized_code() && code->marked_for_deoptimization();
|
| -}
|
| -
|
| -
|
| -bool MarkCompactCollector::MarkInvalidatedCode() {
|
| - bool code_marked = false;
|
| -
|
| - int length = invalidated_code_.length();
|
| - for (int i = 0; i < length; i++) {
|
| - Code* code = invalidated_code_[i];
|
| -
|
| - if (SetMarkBitsUnderInvalidatedCode(code, true)) {
|
| - code_marked = true;
|
| - }
|
| - }
|
| -
|
| - return code_marked;
|
| -}
|
| -
|
| -
|
| -void MarkCompactCollector::RemoveDeadInvalidatedCode() {
|
| - int length = invalidated_code_.length();
|
| - for (int i = 0; i < length; i++) {
|
| - if (!IsMarked(invalidated_code_[i])) invalidated_code_[i] = NULL;
|
| - }
|
| -}
|
| -
|
| -
|
| -void MarkCompactCollector::ProcessInvalidatedCode(ObjectVisitor* visitor) {
|
| - int length = invalidated_code_.length();
|
| - for (int i = 0; i < length; i++) {
|
| - Code* code = invalidated_code_[i];
|
| - if (code != NULL) {
|
| - code->Iterate(visitor);
|
| - SetMarkBitsUnderInvalidatedCode(code, false);
|
| - }
|
| - }
|
| - invalidated_code_.Rewind(0);
|
| -}
|
| -
|
| -
|
| -void MarkCompactCollector::EvacuateNewSpaceAndCandidates() {
|
| - Heap::RelocationLock relocation_lock(heap());
|
| -
|
| - bool code_slots_filtering_required;
|
| - { GCTracer::Scope gc_scope(heap()->tracer(),
|
| - GCTracer::Scope::MC_SWEEP_NEWSPACE);
|
| - code_slots_filtering_required = MarkInvalidatedCode();
|
| - EvacuateNewSpace();
|
| - }
|
| -
|
| - { GCTracer::Scope gc_scope(heap()->tracer(),
|
| - GCTracer::Scope::MC_EVACUATE_PAGES);
|
| - EvacuatePages();
|
| - }
|
| -
|
| - // Second pass: find pointers to new space and update them.
|
| - PointersUpdatingVisitor updating_visitor(heap());
|
| -
|
| - { GCTracer::Scope gc_scope(heap()->tracer(),
|
| - GCTracer::Scope::MC_UPDATE_NEW_TO_NEW_POINTERS);
|
| - // Update pointers in to space.
|
| - SemiSpaceIterator to_it(heap()->new_space()->bottom(),
|
| - heap()->new_space()->top());
|
| - for (HeapObject* object = to_it.Next();
|
| - object != NULL;
|
| - object = to_it.Next()) {
|
| - Map* map = object->map();
|
| - object->IterateBody(map->instance_type(),
|
| - object->SizeFromMap(map),
|
| - &updating_visitor);
|
| - }
|
| - }
|
| -
|
| - { GCTracer::Scope gc_scope(heap()->tracer(),
|
| - GCTracer::Scope::MC_UPDATE_ROOT_TO_NEW_POINTERS);
|
| - // Update roots.
|
| - heap_->IterateRoots(&updating_visitor, VISIT_ALL_IN_SWEEP_NEWSPACE);
|
| - }
|
| -
|
| - { GCTracer::Scope gc_scope(heap()->tracer(),
|
| - GCTracer::Scope::MC_UPDATE_OLD_TO_NEW_POINTERS);
|
| - StoreBufferRebuildScope scope(heap_,
|
| - heap_->store_buffer(),
|
| - &Heap::ScavengeStoreBufferCallback);
|
| - heap_->store_buffer()->IteratePointersToNewSpaceAndClearMaps(
|
| - &UpdatePointer);
|
| - }
|
| -
|
| - { GCTracer::Scope gc_scope(heap()->tracer(),
|
| - GCTracer::Scope::MC_UPDATE_POINTERS_TO_EVACUATED);
|
| - SlotsBuffer::UpdateSlotsRecordedIn(heap_,
|
| - migration_slots_buffer_,
|
| - code_slots_filtering_required);
|
| - if (FLAG_trace_fragmentation) {
|
| - PrintF(" migration slots buffer: %d\n",
|
| - SlotsBuffer::SizeOfChain(migration_slots_buffer_));
|
| - }
|
| -
|
| - if (compacting_ && was_marked_incrementally_) {
|
| - // It's difficult to filter out slots recorded for large objects.
|
| - LargeObjectIterator it(heap_->lo_space());
|
| - for (HeapObject* obj = it.Next(); obj != NULL; obj = it.Next()) {
|
| - // LargeObjectSpace is not swept yet thus we have to skip
|
| - // dead objects explicitly.
|
| - if (!IsMarked(obj)) continue;
|
| -
|
| - Page* p = Page::FromAddress(obj->address());
|
| - if (p->IsFlagSet(Page::RESCAN_ON_EVACUATION)) {
|
| - obj->Iterate(&updating_visitor);
|
| - p->ClearFlag(Page::RESCAN_ON_EVACUATION);
|
| - }
|
| - }
|
| - }
|
| - }
|
| -
|
| - int npages = evacuation_candidates_.length();
|
| - { GCTracer::Scope gc_scope(
|
| - heap()->tracer(), GCTracer::Scope::MC_UPDATE_POINTERS_BETWEEN_EVACUATED);
|
| - for (int i = 0; i < npages; i++) {
|
| - Page* p = evacuation_candidates_[i];
|
| - DCHECK(p->IsEvacuationCandidate() ||
|
| - p->IsFlagSet(Page::RESCAN_ON_EVACUATION));
|
| -
|
| - if (p->IsEvacuationCandidate()) {
|
| - SlotsBuffer::UpdateSlotsRecordedIn(heap_,
|
| - p->slots_buffer(),
|
| - code_slots_filtering_required);
|
| - if (FLAG_trace_fragmentation) {
|
| - PrintF(" page %p slots buffer: %d\n",
|
| - reinterpret_cast<void*>(p),
|
| - SlotsBuffer::SizeOfChain(p->slots_buffer()));
|
| - }
|
| -
|
| - // Important: skip list should be cleared only after roots were updated
|
| - // because root iteration traverses the stack and might have to find
|
| - // code objects from non-updated pc pointing into evacuation candidate.
|
| - SkipList* list = p->skip_list();
|
| - if (list != NULL) list->Clear();
|
| - } else {
|
| - if (FLAG_gc_verbose) {
|
| - PrintF("Sweeping 0x%" V8PRIxPTR " during evacuation.\n",
|
| - reinterpret_cast<intptr_t>(p));
|
| - }
|
| - PagedSpace* space = static_cast<PagedSpace*>(p->owner());
|
| - p->ClearFlag(MemoryChunk::RESCAN_ON_EVACUATION);
|
| -
|
| - switch (space->identity()) {
|
| - case OLD_DATA_SPACE:
|
| - SweepConservatively<SWEEP_ON_MAIN_THREAD>(space, NULL, p);
|
| - break;
|
| - case OLD_POINTER_SPACE:
|
| - SweepPrecisely<SWEEP_AND_VISIT_LIVE_OBJECTS,
|
| - SWEEP_ON_MAIN_THREAD,
|
| - IGNORE_SKIP_LIST,
|
| - IGNORE_FREE_SPACE>(
|
| - space, NULL, p, &updating_visitor);
|
| - break;
|
| - case CODE_SPACE:
|
| - if (FLAG_zap_code_space) {
|
| - SweepPrecisely<SWEEP_AND_VISIT_LIVE_OBJECTS,
|
| - SWEEP_ON_MAIN_THREAD,
|
| - REBUILD_SKIP_LIST,
|
| - ZAP_FREE_SPACE>(
|
| - space, NULL, p, &updating_visitor);
|
| - } else {
|
| - SweepPrecisely<SWEEP_AND_VISIT_LIVE_OBJECTS,
|
| - SWEEP_ON_MAIN_THREAD,
|
| - REBUILD_SKIP_LIST,
|
| - IGNORE_FREE_SPACE>(
|
| - space, NULL, p, &updating_visitor);
|
| - }
|
| - break;
|
| - default:
|
| - UNREACHABLE();
|
| - break;
|
| - }
|
| - }
|
| - }
|
| - }
|
| -
|
| - GCTracer::Scope gc_scope(heap()->tracer(),
|
| - GCTracer::Scope::MC_UPDATE_MISC_POINTERS);
|
| -
|
| - // Update pointers from cells.
|
| - HeapObjectIterator cell_iterator(heap_->cell_space());
|
| - for (HeapObject* cell = cell_iterator.Next();
|
| - cell != NULL;
|
| - cell = cell_iterator.Next()) {
|
| - if (cell->IsCell()) {
|
| - Cell::BodyDescriptor::IterateBody(cell, &updating_visitor);
|
| - }
|
| - }
|
| -
|
| - HeapObjectIterator js_global_property_cell_iterator(
|
| - heap_->property_cell_space());
|
| - for (HeapObject* cell = js_global_property_cell_iterator.Next();
|
| - cell != NULL;
|
| - cell = js_global_property_cell_iterator.Next()) {
|
| - if (cell->IsPropertyCell()) {
|
| - PropertyCell::BodyDescriptor::IterateBody(cell, &updating_visitor);
|
| - }
|
| - }
|
| -
|
| - heap_->string_table()->Iterate(&updating_visitor);
|
| - updating_visitor.VisitPointer(heap_->weak_object_to_code_table_address());
|
| - if (heap_->weak_object_to_code_table()->IsHashTable()) {
|
| - WeakHashTable* table =
|
| - WeakHashTable::cast(heap_->weak_object_to_code_table());
|
| - table->Iterate(&updating_visitor);
|
| - table->Rehash(heap_->isolate()->factory()->undefined_value());
|
| - }
|
| -
|
| - // Update pointers from external string table.
|
| - heap_->UpdateReferencesInExternalStringTable(
|
| - &UpdateReferenceInExternalStringTableEntry);
|
| -
|
| - EvacuationWeakObjectRetainer evacuation_object_retainer;
|
| - heap()->ProcessWeakReferences(&evacuation_object_retainer);
|
| -
|
| - // Visit invalidated code (we ignored all slots on it) and clear mark-bits
|
| - // under it.
|
| - ProcessInvalidatedCode(&updating_visitor);
|
| -
|
| - heap_->isolate()->inner_pointer_to_code_cache()->Flush();
|
| -
|
| - slots_buffer_allocator_.DeallocateChain(&migration_slots_buffer_);
|
| - DCHECK(migration_slots_buffer_ == NULL);
|
| -}
|
| -
|
| -
|
| -void MarkCompactCollector::MoveEvacuationCandidatesToEndOfPagesList() {
|
| - int npages = evacuation_candidates_.length();
|
| - for (int i = 0; i < npages; i++) {
|
| - Page* p = evacuation_candidates_[i];
|
| - if (!p->IsEvacuationCandidate()) continue;
|
| - p->Unlink();
|
| - PagedSpace* space = static_cast<PagedSpace*>(p->owner());
|
| - p->InsertAfter(space->LastPage());
|
| - }
|
| -}
|
| -
|
| -
|
| -void MarkCompactCollector::ReleaseEvacuationCandidates() {
|
| - int npages = evacuation_candidates_.length();
|
| - for (int i = 0; i < npages; i++) {
|
| - Page* p = evacuation_candidates_[i];
|
| - if (!p->IsEvacuationCandidate()) continue;
|
| - PagedSpace* space = static_cast<PagedSpace*>(p->owner());
|
| - space->Free(p->area_start(), p->area_size());
|
| - p->set_scan_on_scavenge(false);
|
| - slots_buffer_allocator_.DeallocateChain(p->slots_buffer_address());
|
| - p->ResetLiveBytes();
|
| - space->ReleasePage(p);
|
| - }
|
| - evacuation_candidates_.Rewind(0);
|
| - compacting_ = false;
|
| - heap()->FreeQueuedChunks();
|
| -}
|
| -
|
| -
|
| -static const int kStartTableEntriesPerLine = 5;
|
| -static const int kStartTableLines = 171;
|
| -static const int kStartTableInvalidLine = 127;
|
| -static const int kStartTableUnusedEntry = 126;
|
| -
|
| -#define _ kStartTableUnusedEntry
|
| -#define X kStartTableInvalidLine
|
| -// Mark-bit to object start offset table.
|
| -//
|
| -// The line is indexed by the mark bits in a byte. The first number on
|
| -// the line describes the number of live object starts for the line and the
|
| -// other numbers on the line describe the offsets (in words) of the object
|
| -// starts.
|
| -//
|
| -// Since objects are at least 2 words large we don't have entries for two
|
| -// consecutive 1 bits. All entries after 170 have at least 2 consecutive bits.
|
| -char kStartTable[kStartTableLines * kStartTableEntriesPerLine] = {
|
| - 0, _, _, _, _, // 0
|
| - 1, 0, _, _, _, // 1
|
| - 1, 1, _, _, _, // 2
|
| - X, _, _, _, _, // 3
|
| - 1, 2, _, _, _, // 4
|
| - 2, 0, 2, _, _, // 5
|
| - X, _, _, _, _, // 6
|
| - X, _, _, _, _, // 7
|
| - 1, 3, _, _, _, // 8
|
| - 2, 0, 3, _, _, // 9
|
| - 2, 1, 3, _, _, // 10
|
| - X, _, _, _, _, // 11
|
| - X, _, _, _, _, // 12
|
| - X, _, _, _, _, // 13
|
| - X, _, _, _, _, // 14
|
| - X, _, _, _, _, // 15
|
| - 1, 4, _, _, _, // 16
|
| - 2, 0, 4, _, _, // 17
|
| - 2, 1, 4, _, _, // 18
|
| - X, _, _, _, _, // 19
|
| - 2, 2, 4, _, _, // 20
|
| - 3, 0, 2, 4, _, // 21
|
| - X, _, _, _, _, // 22
|
| - X, _, _, _, _, // 23
|
| - X, _, _, _, _, // 24
|
| - X, _, _, _, _, // 25
|
| - X, _, _, _, _, // 26
|
| - X, _, _, _, _, // 27
|
| - X, _, _, _, _, // 28
|
| - X, _, _, _, _, // 29
|
| - X, _, _, _, _, // 30
|
| - X, _, _, _, _, // 31
|
| - 1, 5, _, _, _, // 32
|
| - 2, 0, 5, _, _, // 33
|
| - 2, 1, 5, _, _, // 34
|
| - X, _, _, _, _, // 35
|
| - 2, 2, 5, _, _, // 36
|
| - 3, 0, 2, 5, _, // 37
|
| - X, _, _, _, _, // 38
|
| - X, _, _, _, _, // 39
|
| - 2, 3, 5, _, _, // 40
|
| - 3, 0, 3, 5, _, // 41
|
| - 3, 1, 3, 5, _, // 42
|
| - X, _, _, _, _, // 43
|
| - X, _, _, _, _, // 44
|
| - X, _, _, _, _, // 45
|
| - X, _, _, _, _, // 46
|
| - X, _, _, _, _, // 47
|
| - X, _, _, _, _, // 48
|
| - X, _, _, _, _, // 49
|
| - X, _, _, _, _, // 50
|
| - X, _, _, _, _, // 51
|
| - X, _, _, _, _, // 52
|
| - X, _, _, _, _, // 53
|
| - X, _, _, _, _, // 54
|
| - X, _, _, _, _, // 55
|
| - X, _, _, _, _, // 56
|
| - X, _, _, _, _, // 57
|
| - X, _, _, _, _, // 58
|
| - X, _, _, _, _, // 59
|
| - X, _, _, _, _, // 60
|
| - X, _, _, _, _, // 61
|
| - X, _, _, _, _, // 62
|
| - X, _, _, _, _, // 63
|
| - 1, 6, _, _, _, // 64
|
| - 2, 0, 6, _, _, // 65
|
| - 2, 1, 6, _, _, // 66
|
| - X, _, _, _, _, // 67
|
| - 2, 2, 6, _, _, // 68
|
| - 3, 0, 2, 6, _, // 69
|
| - X, _, _, _, _, // 70
|
| - X, _, _, _, _, // 71
|
| - 2, 3, 6, _, _, // 72
|
| - 3, 0, 3, 6, _, // 73
|
| - 3, 1, 3, 6, _, // 74
|
| - X, _, _, _, _, // 75
|
| - X, _, _, _, _, // 76
|
| - X, _, _, _, _, // 77
|
| - X, _, _, _, _, // 78
|
| - X, _, _, _, _, // 79
|
| - 2, 4, 6, _, _, // 80
|
| - 3, 0, 4, 6, _, // 81
|
| - 3, 1, 4, 6, _, // 82
|
| - X, _, _, _, _, // 83
|
| - 3, 2, 4, 6, _, // 84
|
| - 4, 0, 2, 4, 6, // 85
|
| - X, _, _, _, _, // 86
|
| - X, _, _, _, _, // 87
|
| - X, _, _, _, _, // 88
|
| - X, _, _, _, _, // 89
|
| - X, _, _, _, _, // 90
|
| - X, _, _, _, _, // 91
|
| - X, _, _, _, _, // 92
|
| - X, _, _, _, _, // 93
|
| - X, _, _, _, _, // 94
|
| - X, _, _, _, _, // 95
|
| - X, _, _, _, _, // 96
|
| - X, _, _, _, _, // 97
|
| - X, _, _, _, _, // 98
|
| - X, _, _, _, _, // 99
|
| - X, _, _, _, _, // 100
|
| - X, _, _, _, _, // 101
|
| - X, _, _, _, _, // 102
|
| - X, _, _, _, _, // 103
|
| - X, _, _, _, _, // 104
|
| - X, _, _, _, _, // 105
|
| - X, _, _, _, _, // 106
|
| - X, _, _, _, _, // 107
|
| - X, _, _, _, _, // 108
|
| - X, _, _, _, _, // 109
|
| - X, _, _, _, _, // 110
|
| - X, _, _, _, _, // 111
|
| - X, _, _, _, _, // 112
|
| - X, _, _, _, _, // 113
|
| - X, _, _, _, _, // 114
|
| - X, _, _, _, _, // 115
|
| - X, _, _, _, _, // 116
|
| - X, _, _, _, _, // 117
|
| - X, _, _, _, _, // 118
|
| - X, _, _, _, _, // 119
|
| - X, _, _, _, _, // 120
|
| - X, _, _, _, _, // 121
|
| - X, _, _, _, _, // 122
|
| - X, _, _, _, _, // 123
|
| - X, _, _, _, _, // 124
|
| - X, _, _, _, _, // 125
|
| - X, _, _, _, _, // 126
|
| - X, _, _, _, _, // 127
|
| - 1, 7, _, _, _, // 128
|
| - 2, 0, 7, _, _, // 129
|
| - 2, 1, 7, _, _, // 130
|
| - X, _, _, _, _, // 131
|
| - 2, 2, 7, _, _, // 132
|
| - 3, 0, 2, 7, _, // 133
|
| - X, _, _, _, _, // 134
|
| - X, _, _, _, _, // 135
|
| - 2, 3, 7, _, _, // 136
|
| - 3, 0, 3, 7, _, // 137
|
| - 3, 1, 3, 7, _, // 138
|
| - X, _, _, _, _, // 139
|
| - X, _, _, _, _, // 140
|
| - X, _, _, _, _, // 141
|
| - X, _, _, _, _, // 142
|
| - X, _, _, _, _, // 143
|
| - 2, 4, 7, _, _, // 144
|
| - 3, 0, 4, 7, _, // 145
|
| - 3, 1, 4, 7, _, // 146
|
| - X, _, _, _, _, // 147
|
| - 3, 2, 4, 7, _, // 148
|
| - 4, 0, 2, 4, 7, // 149
|
| - X, _, _, _, _, // 150
|
| - X, _, _, _, _, // 151
|
| - X, _, _, _, _, // 152
|
| - X, _, _, _, _, // 153
|
| - X, _, _, _, _, // 154
|
| - X, _, _, _, _, // 155
|
| - X, _, _, _, _, // 156
|
| - X, _, _, _, _, // 157
|
| - X, _, _, _, _, // 158
|
| - X, _, _, _, _, // 159
|
| - 2, 5, 7, _, _, // 160
|
| - 3, 0, 5, 7, _, // 161
|
| - 3, 1, 5, 7, _, // 162
|
| - X, _, _, _, _, // 163
|
| - 3, 2, 5, 7, _, // 164
|
| - 4, 0, 2, 5, 7, // 165
|
| - X, _, _, _, _, // 166
|
| - X, _, _, _, _, // 167
|
| - 3, 3, 5, 7, _, // 168
|
| - 4, 0, 3, 5, 7, // 169
|
| - 4, 1, 3, 5, 7 // 170
|
| -};
|
| -#undef _
|
| -#undef X
|
| -
|
| -
|
| -// Takes a word of mark bits. Returns the number of objects that start in the
|
| -// range. Puts the offsets of the words in the supplied array.
|
| -static inline int MarkWordToObjectStarts(uint32_t mark_bits, int* starts) {
|
| - int objects = 0;
|
| - int offset = 0;
|
| -
|
| - // No consecutive 1 bits.
|
| - DCHECK((mark_bits & 0x180) != 0x180);
|
| - DCHECK((mark_bits & 0x18000) != 0x18000);
|
| - DCHECK((mark_bits & 0x1800000) != 0x1800000);
|
| -
|
| - while (mark_bits != 0) {
|
| - int byte = (mark_bits & 0xff);
|
| - mark_bits >>= 8;
|
| - if (byte != 0) {
|
| - DCHECK(byte < kStartTableLines); // No consecutive 1 bits.
|
| - char* table = kStartTable + byte * kStartTableEntriesPerLine;
|
| - int objects_in_these_8_words = table[0];
|
| - DCHECK(objects_in_these_8_words != kStartTableInvalidLine);
|
| - DCHECK(objects_in_these_8_words < kStartTableEntriesPerLine);
|
| - for (int i = 0; i < objects_in_these_8_words; i++) {
|
| - starts[objects++] = offset + table[1 + i];
|
| - }
|
| - }
|
| - offset += 8;
|
| - }
|
| - return objects;
|
| -}
|
| -
|
| -
|
| -static inline Address DigestFreeStart(Address approximate_free_start,
|
| - uint32_t free_start_cell) {
|
| - DCHECK(free_start_cell != 0);
|
| -
|
| - // No consecutive 1 bits.
|
| - DCHECK((free_start_cell & (free_start_cell << 1)) == 0);
|
| -
|
| - int offsets[16];
|
| - uint32_t cell = free_start_cell;
|
| - int offset_of_last_live;
|
| - if ((cell & 0x80000000u) != 0) {
|
| - // This case would overflow below.
|
| - offset_of_last_live = 31;
|
| - } else {
|
| - // Remove all but one bit, the most significant. This is an optimization
|
| - // that may or may not be worthwhile.
|
| - cell |= cell >> 16;
|
| - cell |= cell >> 8;
|
| - cell |= cell >> 4;
|
| - cell |= cell >> 2;
|
| - cell |= cell >> 1;
|
| - cell = (cell + 1) >> 1;
|
| - int live_objects = MarkWordToObjectStarts(cell, offsets);
|
| - DCHECK(live_objects == 1);
|
| - offset_of_last_live = offsets[live_objects - 1];
|
| - }
|
| - Address last_live_start =
|
| - approximate_free_start + offset_of_last_live * kPointerSize;
|
| - HeapObject* last_live = HeapObject::FromAddress(last_live_start);
|
| - Address free_start = last_live_start + last_live->Size();
|
| - return free_start;
|
| -}
|
| -
|
| -
|
| -static inline Address StartOfLiveObject(Address block_address, uint32_t cell) {
|
| - DCHECK(cell != 0);
|
| -
|
| - // No consecutive 1 bits.
|
| - DCHECK((cell & (cell << 1)) == 0);
|
| -
|
| - int offsets[16];
|
| - if (cell == 0x80000000u) { // Avoid overflow below.
|
| - return block_address + 31 * kPointerSize;
|
| - }
|
| - uint32_t first_set_bit = ((cell ^ (cell - 1)) + 1) >> 1;
|
| - DCHECK((first_set_bit & cell) == first_set_bit);
|
| - int live_objects = MarkWordToObjectStarts(first_set_bit, offsets);
|
| - DCHECK(live_objects == 1);
|
| - USE(live_objects);
|
| - return block_address + offsets[0] * kPointerSize;
|
| -}
|
| -
|
| -
|
| -// Force instantiation of templatized SweepConservatively method for
|
| -// SWEEP_ON_MAIN_THREAD mode.
|
| -template int MarkCompactCollector::
|
| - SweepConservatively<MarkCompactCollector::SWEEP_ON_MAIN_THREAD>(
|
| - PagedSpace*, FreeList*, Page*);
|
| -
|
| -
|
| -// Force instantiation of templatized SweepConservatively method for
|
| -// SWEEP_IN_PARALLEL mode.
|
| -template int MarkCompactCollector::
|
| - SweepConservatively<MarkCompactCollector::SWEEP_IN_PARALLEL>(
|
| - PagedSpace*, FreeList*, Page*);
|
| -
|
| -
|
| -// Sweeps a space conservatively. After this has been done the larger free
|
| -// spaces have been put on the free list and the smaller ones have been
|
| -// ignored and left untouched. A free space is always either ignored or put
|
| -// on the free list, never split up into two parts. This is important
|
| -// because it means that any FreeSpace maps left actually describe a region of
|
| -// memory that can be ignored when scanning. Dead objects other than free
|
| -// spaces will not contain the free space map.
|
| -template<MarkCompactCollector::SweepingParallelism mode>
|
| -int MarkCompactCollector::SweepConservatively(PagedSpace* space,
|
| - FreeList* free_list,
|
| - Page* p) {
|
| - DCHECK(!p->IsEvacuationCandidate() && !p->WasSwept());
|
| - DCHECK((mode == MarkCompactCollector::SWEEP_IN_PARALLEL &&
|
| - free_list != NULL) ||
|
| - (mode == MarkCompactCollector::SWEEP_ON_MAIN_THREAD &&
|
| - free_list == NULL));
|
| -
|
| - intptr_t freed_bytes = 0;
|
| - intptr_t max_freed_bytes = 0;
|
| - size_t size = 0;
|
| -
|
| - // Skip over all the dead objects at the start of the page and mark them free.
|
| - Address cell_base = 0;
|
| - MarkBit::CellType* cell = NULL;
|
| - MarkBitCellIterator it(p);
|
| - for (; !it.Done(); it.Advance()) {
|
| - cell_base = it.CurrentCellBase();
|
| - cell = it.CurrentCell();
|
| - if (*cell != 0) break;
|
| - }
|
| -
|
| - if (it.Done()) {
|
| - size = p->area_end() - p->area_start();
|
| - freed_bytes = Free<mode>(space, free_list, p->area_start(),
|
| - static_cast<int>(size));
|
| - max_freed_bytes = Max(freed_bytes, max_freed_bytes);
|
| - DCHECK_EQ(0, p->LiveBytes());
|
| - if (mode == MarkCompactCollector::SWEEP_IN_PARALLEL) {
|
| - // When concurrent sweeping is active, the page will be marked after
|
| - // sweeping by the main thread.
|
| - p->set_parallel_sweeping(MemoryChunk::SWEEPING_FINALIZE);
|
| - } else {
|
| - p->MarkSweptConservatively();
|
| - }
|
| - return FreeList::GuaranteedAllocatable(static_cast<int>(max_freed_bytes));
|
| - }
|
| -
|
| - // Grow the size of the start-of-page free space a little to get up to the
|
| - // first live object.
|
| - Address free_end = StartOfLiveObject(cell_base, *cell);
|
| - // Free the first free space.
|
| - size = free_end - p->area_start();
|
| - freed_bytes = Free<mode>(space, free_list, p->area_start(),
|
| - static_cast<int>(size));
|
| - max_freed_bytes = Max(freed_bytes, max_freed_bytes);
|
| -
|
| - // The start of the current free area is represented in undigested form by
|
| - // the address of the last 32-word section that contained a live object and
|
| - // the marking bitmap for that cell, which describes where the live object
|
| - // started. Unless we find a large free space in the bitmap we will not
|
| - // digest this pair into a real address. We start the iteration here at the
|
| - // first word in the marking bit map that indicates a live object.
|
| - Address free_start = cell_base;
|
| - MarkBit::CellType free_start_cell = *cell;
|
| -
|
| - for (; !it.Done(); it.Advance()) {
|
| - cell_base = it.CurrentCellBase();
|
| - cell = it.CurrentCell();
|
| - if (*cell != 0) {
|
| - // We have a live object. Check approximately whether it is more than 32
|
| - // words since the last live object.
|
| - if (cell_base - free_start > 32 * kPointerSize) {
|
| - free_start = DigestFreeStart(free_start, free_start_cell);
|
| - if (cell_base - free_start > 32 * kPointerSize) {
|
| - // Now that we know the exact start of the free space it still looks
|
| - // like we have a large enough free space to be worth bothering with.
|
| - // so now we need to find the start of the first live object at the
|
| - // end of the free space.
|
| - free_end = StartOfLiveObject(cell_base, *cell);
|
| - freed_bytes = Free<mode>(space, free_list, free_start,
|
| - static_cast<int>(free_end - free_start));
|
| - max_freed_bytes = Max(freed_bytes, max_freed_bytes);
|
| - }
|
| - }
|
| - // Update our undigested record of where the current free area started.
|
| - free_start = cell_base;
|
| - free_start_cell = *cell;
|
| - // Clear marking bits for current cell.
|
| - *cell = 0;
|
| - }
|
| - }
|
| -
|
| - // Handle the free space at the end of the page.
|
| - if (cell_base - free_start > 32 * kPointerSize) {
|
| - free_start = DigestFreeStart(free_start, free_start_cell);
|
| - freed_bytes = Free<mode>(space, free_list, free_start,
|
| - static_cast<int>(p->area_end() - free_start));
|
| - max_freed_bytes = Max(freed_bytes, max_freed_bytes);
|
| - }
|
| -
|
| - p->ResetLiveBytes();
|
| - if (mode == MarkCompactCollector::SWEEP_IN_PARALLEL) {
|
| - // When concurrent sweeping is active, the page will be marked after
|
| - // sweeping by the main thread.
|
| - p->set_parallel_sweeping(MemoryChunk::SWEEPING_FINALIZE);
|
| - } else {
|
| - p->MarkSweptConservatively();
|
| - }
|
| - return FreeList::GuaranteedAllocatable(static_cast<int>(max_freed_bytes));
|
| -}
|
| -
|
| -
|
| -int MarkCompactCollector::SweepInParallel(PagedSpace* space,
|
| - int required_freed_bytes) {
|
| - int max_freed = 0;
|
| - int max_freed_overall = 0;
|
| - PageIterator it(space);
|
| - while (it.has_next()) {
|
| - Page* p = it.next();
|
| - max_freed = SweepInParallel(p, space);
|
| - DCHECK(max_freed >= 0);
|
| - if (required_freed_bytes > 0 && max_freed >= required_freed_bytes) {
|
| - return max_freed;
|
| - }
|
| - max_freed_overall = Max(max_freed, max_freed_overall);
|
| - if (p == space->end_of_unswept_pages()) break;
|
| - }
|
| - return max_freed_overall;
|
| -}
|
| -
|
| -
|
| -int MarkCompactCollector::SweepInParallel(Page* page, PagedSpace* space) {
|
| - int max_freed = 0;
|
| - if (page->TryParallelSweeping()) {
|
| - FreeList* free_list = space == heap()->old_pointer_space()
|
| - ? free_list_old_pointer_space_.get()
|
| - : free_list_old_data_space_.get();
|
| - FreeList private_free_list(space);
|
| - if (space->swept_precisely()) {
|
| - max_freed = SweepPrecisely<SWEEP_ONLY, SWEEP_IN_PARALLEL,
|
| - IGNORE_SKIP_LIST, IGNORE_FREE_SPACE>(
|
| - space, &private_free_list, page, NULL);
|
| - } else {
|
| - max_freed = SweepConservatively<SWEEP_IN_PARALLEL>(
|
| - space, &private_free_list, page);
|
| - }
|
| - free_list->Concatenate(&private_free_list);
|
| - }
|
| - return max_freed;
|
| -}
|
| -
|
| -
|
| -void MarkCompactCollector::SweepSpace(PagedSpace* space, SweeperType sweeper) {
|
| - space->set_swept_precisely(sweeper == PRECISE ||
|
| - sweeper == CONCURRENT_PRECISE ||
|
| - sweeper == PARALLEL_PRECISE);
|
| - space->ClearStats();
|
| -
|
| - // We defensively initialize end_of_unswept_pages_ here with the first page
|
| - // of the pages list.
|
| - space->set_end_of_unswept_pages(space->FirstPage());
|
| -
|
| - PageIterator it(space);
|
| -
|
| - int pages_swept = 0;
|
| - bool unused_page_present = false;
|
| - bool parallel_sweeping_active = false;
|
| -
|
| - while (it.has_next()) {
|
| - Page* p = it.next();
|
| - DCHECK(p->parallel_sweeping() == MemoryChunk::SWEEPING_DONE);
|
| -
|
| - // Clear sweeping flags indicating that marking bits are still intact.
|
| - p->ClearSweptPrecisely();
|
| - p->ClearSweptConservatively();
|
| -
|
| - if (p->IsFlagSet(Page::RESCAN_ON_EVACUATION) ||
|
| - p->IsEvacuationCandidate()) {
|
| - // Will be processed in EvacuateNewSpaceAndCandidates.
|
| - DCHECK(evacuation_candidates_.length() > 0);
|
| - continue;
|
| - }
|
| -
|
| - // One unused page is kept, all further are released before sweeping them.
|
| - if (p->LiveBytes() == 0) {
|
| - if (unused_page_present) {
|
| - if (FLAG_gc_verbose) {
|
| - PrintF("Sweeping 0x%" V8PRIxPTR " released page.\n",
|
| - reinterpret_cast<intptr_t>(p));
|
| - }
|
| - // Adjust unswept free bytes because releasing a page expects said
|
| - // counter to be accurate for unswept pages.
|
| - space->IncreaseUnsweptFreeBytes(p);
|
| - space->ReleasePage(p);
|
| - continue;
|
| - }
|
| - unused_page_present = true;
|
| - }
|
| -
|
| - switch (sweeper) {
|
| - case CONCURRENT_CONSERVATIVE:
|
| - case PARALLEL_CONSERVATIVE: {
|
| - if (!parallel_sweeping_active) {
|
| - if (FLAG_gc_verbose) {
|
| - PrintF("Sweeping 0x%" V8PRIxPTR " conservatively.\n",
|
| - reinterpret_cast<intptr_t>(p));
|
| - }
|
| - SweepConservatively<SWEEP_ON_MAIN_THREAD>(space, NULL, p);
|
| - pages_swept++;
|
| - parallel_sweeping_active = true;
|
| - } else {
|
| - if (FLAG_gc_verbose) {
|
| - PrintF("Sweeping 0x%" V8PRIxPTR " conservatively in parallel.\n",
|
| - reinterpret_cast<intptr_t>(p));
|
| - }
|
| - p->set_parallel_sweeping(MemoryChunk::SWEEPING_PENDING);
|
| - space->IncreaseUnsweptFreeBytes(p);
|
| - }
|
| - space->set_end_of_unswept_pages(p);
|
| - break;
|
| - }
|
| - case CONCURRENT_PRECISE:
|
| - case PARALLEL_PRECISE:
|
| - if (!parallel_sweeping_active) {
|
| - if (FLAG_gc_verbose) {
|
| - PrintF("Sweeping 0x%" V8PRIxPTR " precisely.\n",
|
| - reinterpret_cast<intptr_t>(p));
|
| - }
|
| - SweepPrecisely<SWEEP_ONLY,
|
| - SWEEP_ON_MAIN_THREAD,
|
| - IGNORE_SKIP_LIST,
|
| - IGNORE_FREE_SPACE>(space, NULL, p, NULL);
|
| - pages_swept++;
|
| - parallel_sweeping_active = true;
|
| - } else {
|
| - if (FLAG_gc_verbose) {
|
| - PrintF("Sweeping 0x%" V8PRIxPTR " conservatively in parallel.\n",
|
| - reinterpret_cast<intptr_t>(p));
|
| - }
|
| - p->set_parallel_sweeping(MemoryChunk::SWEEPING_PENDING);
|
| - space->IncreaseUnsweptFreeBytes(p);
|
| - }
|
| - space->set_end_of_unswept_pages(p);
|
| - break;
|
| - case PRECISE: {
|
| - if (FLAG_gc_verbose) {
|
| - PrintF("Sweeping 0x%" V8PRIxPTR " precisely.\n",
|
| - reinterpret_cast<intptr_t>(p));
|
| - }
|
| - if (space->identity() == CODE_SPACE && FLAG_zap_code_space) {
|
| - SweepPrecisely<SWEEP_ONLY,
|
| - SWEEP_ON_MAIN_THREAD,
|
| - REBUILD_SKIP_LIST,
|
| - ZAP_FREE_SPACE>(space, NULL, p, NULL);
|
| - } else if (space->identity() == CODE_SPACE) {
|
| - SweepPrecisely<SWEEP_ONLY,
|
| - SWEEP_ON_MAIN_THREAD,
|
| - REBUILD_SKIP_LIST,
|
| - IGNORE_FREE_SPACE>(space, NULL, p, NULL);
|
| - } else {
|
| - SweepPrecisely<SWEEP_ONLY,
|
| - SWEEP_ON_MAIN_THREAD,
|
| - IGNORE_SKIP_LIST,
|
| - IGNORE_FREE_SPACE>(space, NULL, p, NULL);
|
| - }
|
| - pages_swept++;
|
| - break;
|
| - }
|
| - default: {
|
| - UNREACHABLE();
|
| - }
|
| - }
|
| - }
|
| -
|
| - if (FLAG_gc_verbose) {
|
| - PrintF("SweepSpace: %s (%d pages swept)\n",
|
| - AllocationSpaceName(space->identity()),
|
| - pages_swept);
|
| - }
|
| -
|
| - // Give pages that are queued to be freed back to the OS.
|
| - heap()->FreeQueuedChunks();
|
| -}
|
| -
|
| -
|
| -static bool ShouldStartSweeperThreads(MarkCompactCollector::SweeperType type) {
|
| - return type == MarkCompactCollector::PARALLEL_CONSERVATIVE ||
|
| - type == MarkCompactCollector::CONCURRENT_CONSERVATIVE ||
|
| - type == MarkCompactCollector::PARALLEL_PRECISE ||
|
| - type == MarkCompactCollector::CONCURRENT_PRECISE;
|
| -}
|
| -
|
| -
|
| -static bool ShouldWaitForSweeperThreads(
|
| - MarkCompactCollector::SweeperType type) {
|
| - return type == MarkCompactCollector::PARALLEL_CONSERVATIVE ||
|
| - type == MarkCompactCollector::PARALLEL_PRECISE;
|
| -}
|
| -
|
| -
|
| -void MarkCompactCollector::SweepSpaces() {
|
| - GCTracer::Scope gc_scope(heap()->tracer(), GCTracer::Scope::MC_SWEEP);
|
| - double start_time = 0.0;
|
| - if (FLAG_print_cumulative_gc_stat) {
|
| - start_time = base::OS::TimeCurrentMillis();
|
| - }
|
| -
|
| -#ifdef DEBUG
|
| - state_ = SWEEP_SPACES;
|
| -#endif
|
| - SweeperType how_to_sweep = CONCURRENT_CONSERVATIVE;
|
| - if (FLAG_parallel_sweeping) how_to_sweep = PARALLEL_CONSERVATIVE;
|
| - if (FLAG_concurrent_sweeping) how_to_sweep = CONCURRENT_CONSERVATIVE;
|
| - if (FLAG_always_precise_sweeping && FLAG_parallel_sweeping) {
|
| - how_to_sweep = PARALLEL_PRECISE;
|
| - }
|
| - if (FLAG_always_precise_sweeping && FLAG_concurrent_sweeping) {
|
| - how_to_sweep = CONCURRENT_PRECISE;
|
| - }
|
| - if (sweep_precisely_) how_to_sweep = PRECISE;
|
| -
|
| - MoveEvacuationCandidatesToEndOfPagesList();
|
| -
|
| - // Noncompacting collections simply sweep the spaces to clear the mark
|
| - // bits and free the nonlive blocks (for old and map spaces). We sweep
|
| - // the map space last because freeing non-live maps overwrites them and
|
| - // the other spaces rely on possibly non-live maps to get the sizes for
|
| - // non-live objects.
|
| - { GCTracer::Scope sweep_scope(heap()->tracer(),
|
| - GCTracer::Scope::MC_SWEEP_OLDSPACE);
|
| - { SequentialSweepingScope scope(this);
|
| - SweepSpace(heap()->old_pointer_space(), how_to_sweep);
|
| - SweepSpace(heap()->old_data_space(), how_to_sweep);
|
| - }
|
| -
|
| - if (ShouldStartSweeperThreads(how_to_sweep)) {
|
| - StartSweeperThreads();
|
| - }
|
| -
|
| - if (ShouldWaitForSweeperThreads(how_to_sweep)) {
|
| - EnsureSweepingCompleted();
|
| - }
|
| - }
|
| - RemoveDeadInvalidatedCode();
|
| -
|
| - { GCTracer::Scope sweep_scope(heap()->tracer(),
|
| - GCTracer::Scope::MC_SWEEP_CODE);
|
| - SweepSpace(heap()->code_space(), PRECISE);
|
| - }
|
| -
|
| - { GCTracer::Scope sweep_scope(heap()->tracer(),
|
| - GCTracer::Scope::MC_SWEEP_CELL);
|
| - SweepSpace(heap()->cell_space(), PRECISE);
|
| - SweepSpace(heap()->property_cell_space(), PRECISE);
|
| - }
|
| -
|
| - EvacuateNewSpaceAndCandidates();
|
| -
|
| - // ClearNonLiveTransitions depends on precise sweeping of map space to
|
| - // detect whether unmarked map became dead in this collection or in one
|
| - // of the previous ones.
|
| - { GCTracer::Scope sweep_scope(heap()->tracer(),
|
| - GCTracer::Scope::MC_SWEEP_MAP);
|
| - SweepSpace(heap()->map_space(), PRECISE);
|
| - }
|
| -
|
| - // Deallocate unmarked objects and clear marked bits for marked objects.
|
| - heap_->lo_space()->FreeUnmarkedObjects();
|
| -
|
| - // Deallocate evacuated candidate pages.
|
| - ReleaseEvacuationCandidates();
|
| -
|
| - if (FLAG_print_cumulative_gc_stat) {
|
| - heap_->tracer()->AddSweepingTime(base::OS::TimeCurrentMillis() -
|
| - start_time);
|
| - }
|
| -}
|
| -
|
| -
|
| -void MarkCompactCollector::ParallelSweepSpaceComplete(PagedSpace* space) {
|
| - PageIterator it(space);
|
| - while (it.has_next()) {
|
| - Page* p = it.next();
|
| - if (p->parallel_sweeping() == MemoryChunk::SWEEPING_FINALIZE) {
|
| - p->set_parallel_sweeping(MemoryChunk::SWEEPING_DONE);
|
| - if (space->swept_precisely()) {
|
| - p->MarkSweptPrecisely();
|
| - } else {
|
| - p->MarkSweptConservatively();
|
| - }
|
| - }
|
| - DCHECK(p->parallel_sweeping() == MemoryChunk::SWEEPING_DONE);
|
| - }
|
| -}
|
| -
|
| -
|
| -void MarkCompactCollector::ParallelSweepSpacesComplete() {
|
| - ParallelSweepSpaceComplete(heap()->old_pointer_space());
|
| - ParallelSweepSpaceComplete(heap()->old_data_space());
|
| -}
|
| -
|
| -
|
| -void MarkCompactCollector::EnableCodeFlushing(bool enable) {
|
| - if (isolate()->debug()->is_loaded() ||
|
| - isolate()->debug()->has_break_points()) {
|
| - enable = false;
|
| - }
|
| -
|
| - if (enable) {
|
| - if (code_flusher_ != NULL) return;
|
| - code_flusher_ = new CodeFlusher(isolate());
|
| - } else {
|
| - if (code_flusher_ == NULL) return;
|
| - code_flusher_->EvictAllCandidates();
|
| - delete code_flusher_;
|
| - code_flusher_ = NULL;
|
| - }
|
| -
|
| - if (FLAG_trace_code_flushing) {
|
| - PrintF("[code-flushing is now %s]\n", enable ? "on" : "off");
|
| - }
|
| -}
|
| -
|
| -
|
| -// TODO(1466) ReportDeleteIfNeeded is not called currently.
|
| -// Our profiling tools do not expect intersections between
|
| -// code objects. We should either reenable it or change our tools.
|
| -void MarkCompactCollector::ReportDeleteIfNeeded(HeapObject* obj,
|
| - Isolate* isolate) {
|
| - if (obj->IsCode()) {
|
| - PROFILE(isolate, CodeDeleteEvent(obj->address()));
|
| - }
|
| -}
|
| -
|
| -
|
| -Isolate* MarkCompactCollector::isolate() const {
|
| - return heap_->isolate();
|
| -}
|
| -
|
| -
|
| -void MarkCompactCollector::Initialize() {
|
| - MarkCompactMarkingVisitor::Initialize();
|
| - IncrementalMarking::Initialize();
|
| -}
|
| -
|
| -
|
| -bool SlotsBuffer::IsTypedSlot(ObjectSlot slot) {
|
| - return reinterpret_cast<uintptr_t>(slot) < NUMBER_OF_SLOT_TYPES;
|
| -}
|
| -
|
| -
|
| -bool SlotsBuffer::AddTo(SlotsBufferAllocator* allocator,
|
| - SlotsBuffer** buffer_address,
|
| - SlotType type,
|
| - Address addr,
|
| - AdditionMode mode) {
|
| - SlotsBuffer* buffer = *buffer_address;
|
| - if (buffer == NULL || !buffer->HasSpaceForTypedSlot()) {
|
| - if (mode == FAIL_ON_OVERFLOW && ChainLengthThresholdReached(buffer)) {
|
| - allocator->DeallocateChain(buffer_address);
|
| - return false;
|
| - }
|
| - buffer = allocator->AllocateBuffer(buffer);
|
| - *buffer_address = buffer;
|
| - }
|
| - DCHECK(buffer->HasSpaceForTypedSlot());
|
| - buffer->Add(reinterpret_cast<ObjectSlot>(type));
|
| - buffer->Add(reinterpret_cast<ObjectSlot>(addr));
|
| - return true;
|
| -}
|
| -
|
| -
|
| -static inline SlotsBuffer::SlotType SlotTypeForRMode(RelocInfo::Mode rmode) {
|
| - if (RelocInfo::IsCodeTarget(rmode)) {
|
| - return SlotsBuffer::CODE_TARGET_SLOT;
|
| - } else if (RelocInfo::IsEmbeddedObject(rmode)) {
|
| - return SlotsBuffer::EMBEDDED_OBJECT_SLOT;
|
| - } else if (RelocInfo::IsDebugBreakSlot(rmode)) {
|
| - return SlotsBuffer::DEBUG_TARGET_SLOT;
|
| - } else if (RelocInfo::IsJSReturn(rmode)) {
|
| - return SlotsBuffer::JS_RETURN_SLOT;
|
| - }
|
| - UNREACHABLE();
|
| - return SlotsBuffer::NUMBER_OF_SLOT_TYPES;
|
| -}
|
| -
|
| -
|
| -void MarkCompactCollector::RecordRelocSlot(RelocInfo* rinfo, Object* target) {
|
| - Page* target_page = Page::FromAddress(reinterpret_cast<Address>(target));
|
| - RelocInfo::Mode rmode = rinfo->rmode();
|
| - if (target_page->IsEvacuationCandidate() &&
|
| - (rinfo->host() == NULL ||
|
| - !ShouldSkipEvacuationSlotRecording(rinfo->host()))) {
|
| - bool success;
|
| - if (RelocInfo::IsEmbeddedObject(rmode) && rinfo->IsInConstantPool()) {
|
| - // This doesn't need to be typed since it is just a normal heap pointer.
|
| - Object** target_pointer =
|
| - reinterpret_cast<Object**>(rinfo->constant_pool_entry_address());
|
| - success = SlotsBuffer::AddTo(&slots_buffer_allocator_,
|
| - target_page->slots_buffer_address(),
|
| - target_pointer,
|
| - SlotsBuffer::FAIL_ON_OVERFLOW);
|
| - } else if (RelocInfo::IsCodeTarget(rmode) && rinfo->IsInConstantPool()) {
|
| - success = SlotsBuffer::AddTo(&slots_buffer_allocator_,
|
| - target_page->slots_buffer_address(),
|
| - SlotsBuffer::CODE_ENTRY_SLOT,
|
| - rinfo->constant_pool_entry_address(),
|
| - SlotsBuffer::FAIL_ON_OVERFLOW);
|
| - } else {
|
| - success = SlotsBuffer::AddTo(&slots_buffer_allocator_,
|
| - target_page->slots_buffer_address(),
|
| - SlotTypeForRMode(rmode),
|
| - rinfo->pc(),
|
| - SlotsBuffer::FAIL_ON_OVERFLOW);
|
| - }
|
| - if (!success) {
|
| - EvictEvacuationCandidate(target_page);
|
| - }
|
| - }
|
| -}
|
| -
|
| -
|
| -void MarkCompactCollector::RecordCodeEntrySlot(Address slot, Code* target) {
|
| - Page* target_page = Page::FromAddress(reinterpret_cast<Address>(target));
|
| - if (target_page->IsEvacuationCandidate() &&
|
| - !ShouldSkipEvacuationSlotRecording(reinterpret_cast<Object**>(slot))) {
|
| - if (!SlotsBuffer::AddTo(&slots_buffer_allocator_,
|
| - target_page->slots_buffer_address(),
|
| - SlotsBuffer::CODE_ENTRY_SLOT,
|
| - slot,
|
| - SlotsBuffer::FAIL_ON_OVERFLOW)) {
|
| - EvictEvacuationCandidate(target_page);
|
| - }
|
| - }
|
| -}
|
| -
|
| -
|
| -void MarkCompactCollector::RecordCodeTargetPatch(Address pc, Code* target) {
|
| - DCHECK(heap()->gc_state() == Heap::MARK_COMPACT);
|
| - if (is_compacting()) {
|
| - Code* host = isolate()->inner_pointer_to_code_cache()->
|
| - GcSafeFindCodeForInnerPointer(pc);
|
| - MarkBit mark_bit = Marking::MarkBitFrom(host);
|
| - if (Marking::IsBlack(mark_bit)) {
|
| - RelocInfo rinfo(pc, RelocInfo::CODE_TARGET, 0, host);
|
| - RecordRelocSlot(&rinfo, target);
|
| - }
|
| - }
|
| -}
|
| -
|
| -
|
| -static inline SlotsBuffer::SlotType DecodeSlotType(
|
| - SlotsBuffer::ObjectSlot slot) {
|
| - return static_cast<SlotsBuffer::SlotType>(reinterpret_cast<intptr_t>(slot));
|
| -}
|
| -
|
| -
|
| -void SlotsBuffer::UpdateSlots(Heap* heap) {
|
| - PointersUpdatingVisitor v(heap);
|
| -
|
| - for (int slot_idx = 0; slot_idx < idx_; ++slot_idx) {
|
| - ObjectSlot slot = slots_[slot_idx];
|
| - if (!IsTypedSlot(slot)) {
|
| - PointersUpdatingVisitor::UpdateSlot(heap, slot);
|
| - } else {
|
| - ++slot_idx;
|
| - DCHECK(slot_idx < idx_);
|
| - UpdateSlot(heap->isolate(),
|
| - &v,
|
| - DecodeSlotType(slot),
|
| - reinterpret_cast<Address>(slots_[slot_idx]));
|
| - }
|
| - }
|
| -}
|
| -
|
| -
|
| -void SlotsBuffer::UpdateSlotsWithFilter(Heap* heap) {
|
| - PointersUpdatingVisitor v(heap);
|
| -
|
| - for (int slot_idx = 0; slot_idx < idx_; ++slot_idx) {
|
| - ObjectSlot slot = slots_[slot_idx];
|
| - if (!IsTypedSlot(slot)) {
|
| - if (!IsOnInvalidatedCodeObject(reinterpret_cast<Address>(slot))) {
|
| - PointersUpdatingVisitor::UpdateSlot(heap, slot);
|
| - }
|
| - } else {
|
| - ++slot_idx;
|
| - DCHECK(slot_idx < idx_);
|
| - Address pc = reinterpret_cast<Address>(slots_[slot_idx]);
|
| - if (!IsOnInvalidatedCodeObject(pc)) {
|
| - UpdateSlot(heap->isolate(),
|
| - &v,
|
| - DecodeSlotType(slot),
|
| - reinterpret_cast<Address>(slots_[slot_idx]));
|
| - }
|
| - }
|
| - }
|
| -}
|
| -
|
| -
|
| -SlotsBuffer* SlotsBufferAllocator::AllocateBuffer(SlotsBuffer* next_buffer) {
|
| - return new SlotsBuffer(next_buffer);
|
| -}
|
| -
|
| -
|
| -void SlotsBufferAllocator::DeallocateBuffer(SlotsBuffer* buffer) {
|
| - delete buffer;
|
| -}
|
| -
|
| -
|
| -void SlotsBufferAllocator::DeallocateChain(SlotsBuffer** buffer_address) {
|
| - SlotsBuffer* buffer = *buffer_address;
|
| - while (buffer != NULL) {
|
| - SlotsBuffer* next_buffer = buffer->next();
|
| - DeallocateBuffer(buffer);
|
| - buffer = next_buffer;
|
| - }
|
| - *buffer_address = NULL;
|
| -}
|
| -
|
| -
|
| -} } // namespace v8::internal
|
|
|
Chromium Code Reviews
Issue 437993003:
Move a bunch of GC related files to heap/ subdirectory (Closed)
Base URL: https://v8.googlecode.com/svn/branches/bleeding_edge