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Use weak cells in dependent code.

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BUG=

Review URL: https://codereview.chromium.org/871253005

Cr-Commit-Position: refs/heads/master@{#26614}
This commit is contained in:
ulan 2015-02-12 05:21:06 -08:00 committed by Commit bot
parent 9159c419e8
commit b79b985988
15 changed files with 252 additions and 391 deletions
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2
include/v8.h
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@ -6253,7 +6253,7 @@ class Internals {
static const int kNullValueRootIndex = 7;
static const int kTrueValueRootIndex = 8;
static const int kFalseValueRootIndex = 9;
static const int kEmptyStringRootIndex = 154;
static const int kEmptyStringRootIndex = 155;
// The external allocation limit should be below 256 MB on all architectures
// to avoid that resource-constrained embedders run low on memory.

15
src/compiler.cc
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@ -206,6 +206,16 @@ CompilationInfo::~CompilationInfo() {
void CompilationInfo::CommitDependencies(Handle<Code> code) {
bool has_dependencies = false;
for (int i = 0; i < DependentCode::kGroupCount; i++) {
has_dependencies |=
dependencies_[i] != NULL && dependencies_[i]->length() > 0;
}
// Avoid creating a weak cell for code with no dependencies.
if (!has_dependencies) return;
AllowDeferredHandleDereference get_object_wrapper;
Handle<WeakCell> cell = Code::WeakCellFor(code);
for (int i = 0; i < DependentCode::kGroupCount; i++) {
ZoneList<Handle<HeapObject> >* group_objects = dependencies_[i];
if (group_objects == NULL) continue;
@ -215,7 +225,7 @@ void CompilationInfo::CommitDependencies(Handle<Code> code) {
static_cast<DependentCode::DependencyGroup>(i);
DependentCode* dependent_code =
DependentCode::ForObject(group_objects->at(j), group);
dependent_code->UpdateToFinishedCode(group, this, *code);
dependent_code->UpdateToFinishedCode(group, *object_wrapper(), *cell);
}
dependencies_[i] = NULL; // Zone-allocated, no need to delete.
}
@ -223,6 +233,7 @@ void CompilationInfo::CommitDependencies(Handle<Code> code) {
void CompilationInfo::RollbackDependencies() {
AllowDeferredHandleDereference get_object_wrapper;
// Unregister from all dependent maps if not yet committed.
for (int i = 0; i < DependentCode::kGroupCount; i++) {
ZoneList<Handle<HeapObject> >* group_objects = dependencies_[i];
@ -232,7 +243,7 @@ void CompilationInfo::RollbackDependencies() {
static_cast<DependentCode::DependencyGroup>(i);
DependentCode* dependent_code =
DependentCode::ForObject(group_objects->at(j), group);
dependent_code->RemoveCompilationInfo(group, this);
dependent_code->RemoveCompilationInfo(group, *object_wrapper());
}
dependencies_[i] = NULL; // Zone-allocated, no need to delete.
}

38
src/heap/heap.cc
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@ -135,9 +135,6 @@ Heap::Heap()
full_codegen_bytes_generated_(0),
crankshaft_codegen_bytes_generated_(0),
gcs_since_last_deopt_(0),
#ifdef VERIFY_HEAP
no_weak_object_verification_scope_depth_(0),
#endif
allocation_sites_scratchpad_length_(0),
promotion_queue_(this),
configured_(false),
@ -3169,6 +3166,10 @@ void Heap::CreateInitialObjects() {
set_detached_contexts(empty_fixed_array());
set_weak_object_to_code_table(
*WeakHashTable::New(isolate(), 16, USE_DEFAULT_MINIMUM_CAPACITY,
TENURED));
Handle<SeededNumberDictionary> slow_element_dictionary =
SeededNumberDictionary::New(isolate(), 0, TENURED);
slow_element_dictionary->set_requires_slow_elements();
@ -5600,7 +5601,6 @@ bool Heap::CreateHeapObjects() {
set_array_buffers_list(undefined_value());
set_new_array_buffer_views_list(undefined_value());
set_allocation_sites_list(undefined_value());
weak_object_to_code_table_ = undefined_value();
return true;
}
@ -5775,41 +5775,25 @@ void Heap::RemoveGCEpilogueCallback(v8::Isolate::GCEpilogueCallback callback) {
// TODO(ishell): Find a better place for this.
void Heap::AddWeakObjectToCodeDependency(Handle<Object> obj,
void Heap::AddWeakObjectToCodeDependency(Handle<HeapObject> obj,
Handle<DependentCode> dep) {
DCHECK(!InNewSpace(*obj));
DCHECK(!InNewSpace(*dep));
// This handle scope keeps the table handle local to this function, which
// allows us to safely skip write barriers in table update operations.
HandleScope scope(isolate());
Handle<WeakHashTable> table(WeakHashTable::cast(weak_object_to_code_table_),
isolate());
Handle<WeakHashTable> table(weak_object_to_code_table(), isolate());
table = WeakHashTable::Put(table, obj, dep);
if (ShouldZapGarbage() && weak_object_to_code_table_ != *table) {
WeakHashTable::cast(weak_object_to_code_table_)->Zap(the_hole_value());
}
set_weak_object_to_code_table(*table);
DCHECK_EQ(*dep, table->Lookup(obj));
if (*table != weak_object_to_code_table())
set_weak_object_to_code_table(*table);
DCHECK_EQ(*dep, LookupWeakObjectToCodeDependency(obj));
}
DependentCode* Heap::LookupWeakObjectToCodeDependency(Handle<Object> obj) {
Object* dep = WeakHashTable::cast(weak_object_to_code_table_)->Lookup(obj);
DependentCode* Heap::LookupWeakObjectToCodeDependency(Handle<HeapObject> obj) {
Object* dep = weak_object_to_code_table()->Lookup(obj);
if (dep->IsDependentCode()) return DependentCode::cast(dep);
return DependentCode::cast(empty_fixed_array());
}
void Heap::EnsureWeakObjectToCodeTable() {
if (!weak_object_to_code_table()->IsHashTable()) {
set_weak_object_to_code_table(
*WeakHashTable::New(isolate(), 16, USE_DEFAULT_MINIMUM_CAPACITY,
TENURED));
}
}
void Heap::FatalProcessOutOfMemory(const char* location, bool take_snapshot) {
v8::internal::V8::FatalProcessOutOfMemory(location, take_snapshot);
}

38
src/heap/heap.h
View File

@ -182,7 +182,8 @@ namespace internal {
V(FixedArray, allocation_sites_scratchpad, AllocationSitesScratchpad) \
V(FixedArray, microtask_queue, MicrotaskQueue) \
V(FixedArray, keyed_load_dummy_vector, KeyedLoadDummyVector) \
V(FixedArray, detached_contexts, DetachedContexts)
V(FixedArray, detached_contexts, DetachedContexts) \
V(WeakHashTable, weak_object_to_code_table, WeakObjectToCodeTable)
// Entries in this list are limited to Smis and are not visited during GC.
#define SMI_ROOT_LIST(V) \
@ -873,8 +874,6 @@ class Heap {
// Used in CreateAllocationSiteStub and the (de)serializer.
Object** allocation_sites_list_address() { return &allocation_sites_list_; }
Object* weak_object_to_code_table() { return weak_object_to_code_table_; }
void set_encountered_weak_collections(Object* weak_collection) {
encountered_weak_collections_ = weak_collection;
}
@ -979,11 +978,6 @@ class Heap {
#ifdef VERIFY_HEAP
// Verify the heap is in its normal state before or after a GC.
void Verify();
bool weak_embedded_objects_verification_enabled() {
return no_weak_object_verification_scope_depth_ == 0;
}
#endif
#ifdef DEBUG
@ -1439,16 +1433,10 @@ class Heap {
Heap* heap_;
};
void AddWeakObjectToCodeDependency(Handle<Object> obj,
void AddWeakObjectToCodeDependency(Handle<HeapObject> obj,
Handle<DependentCode> dep);
DependentCode* LookupWeakObjectToCodeDependency(Handle<Object> obj);
void InitializeWeakObjectToCodeTable() {
set_weak_object_to_code_table(undefined_value());
}
void EnsureWeakObjectToCodeTable();
DependentCode* LookupWeakObjectToCodeDependency(Handle<HeapObject> obj);
static void FatalProcessOutOfMemory(const char* location,
bool take_snapshot = false);
@ -1645,11 +1633,6 @@ class Heap {
// array buffer.
Object* new_array_buffer_views_list_;
// WeakHashTable that maps objects embedded in optimized code to dependent
// code list. It is initialized lazily and contains the undefined_value at
// start.
Object* weak_object_to_code_table_;
// List of encountered weak collections (JSWeakMap and JSWeakSet) during
// marking. It is initialized during marking, destroyed after marking and
// contains Smi(0) while marking is not active.
@ -2067,15 +2050,6 @@ class Heap {
void ClearObjectStats(bool clear_last_time_stats = false);
void set_weak_object_to_code_table(Object* value) {
DCHECK(!InNewSpace(value));
weak_object_to_code_table_ = value;
}
Object** weak_object_to_code_table_address() {
return &weak_object_to_code_table_;
}
inline void UpdateAllocationsHash(HeapObject* object);
inline void UpdateAllocationsHash(uint32_t value);
inline void PrintAlloctionsHash();
@ -2127,10 +2101,6 @@ class Heap {
// deoptimization triggered by garbage collection.
int gcs_since_last_deopt_;
#ifdef VERIFY_HEAP
int no_weak_object_verification_scope_depth_;
#endif
static const int kAllocationSiteScratchpadSize = 256;
int allocation_sites_scratchpad_length_;

2
src/heap/incremental-marking.cc
View File

@ -552,8 +552,6 @@ void IncrementalMarking::StartMarking(CompactionFlag flag) {
IncrementalMarkingRootMarkingVisitor visitor(this);
heap_->IterateStrongRoots(&visitor, VISIT_ONLY_STRONG);
heap_->mark_compact_collector()->MarkWeakObjectToCodeTable();
// Ready to start incremental marking.
if (FLAG_trace_incremental_marking) {
PrintF("[IncrementalMarking] Running\n");

199
src/heap/mark-compact.cc
View File

@ -301,10 +301,13 @@ void MarkCompactCollector::CollectGarbage() {
MarkLiveObjects();
DCHECK(heap_->incremental_marking()->IsStopped());
if (FLAG_collect_maps) ClearNonLiveReferences();
// ClearNonLiveReferences can deoptimize code in dependent code arrays.
// Process weak cells before so that weak cells in dependent code
// arrays are cleared or contain only live code objects.
ProcessAndClearWeakCells();
if (FLAG_collect_maps) ClearNonLiveReferences();
ClearWeakCollections();
heap_->set_encountered_weak_cells(Smi::FromInt(0));
@ -318,9 +321,7 @@ void MarkCompactCollector::CollectGarbage() {
SweepSpaces();
#ifdef VERIFY_HEAP
if (heap()->weak_embedded_objects_verification_enabled()) {
VerifyWeakEmbeddedObjectsInCode();
}
VerifyWeakEmbeddedObjectsInCode();
if (FLAG_collect_maps && FLAG_omit_map_checks_for_leaf_maps) {
VerifyOmittedMapChecks();
}
@ -1958,8 +1959,6 @@ void MarkCompactCollector::MarkRoots(RootMarkingVisitor* visitor) {
// Handle the string table specially.
MarkStringTable(visitor);
MarkWeakObjectToCodeTable();
// There may be overflowed objects in the heap. Visit them now.
while (marking_deque_.overflowed()) {
RefillMarkingDeque();
@ -2000,16 +1999,6 @@ void MarkCompactCollector::MarkImplicitRefGroups() {
}
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
@ -2328,67 +2317,29 @@ void MarkCompactCollector::ClearNonLiveReferences() {
ClearNonLivePrototypeTransitions(map);
ClearNonLiveMapTransitions(map, map_mark);
if (map_mark.Get()) {
ClearNonLiveDependentCode(map->dependent_code());
} else {
ClearDependentCode(map->dependent_code());
if (!map_mark.Get()) {
have_code_to_deoptimize_ |=
map->dependent_code()->MarkCodeForDeoptimization(
isolate(), DependentCode::kWeakCodeGroup);
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();
}
WeakHashTable* table = 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 (WeakCell::cast(key)->cleared()) {
have_code_to_deoptimize_ |=
DependentCode::cast(value)->MarkCodeForDeoptimization(
isolate(), DependentCode::kWeakCodeGroup);
table->set(key_index, heap_->the_hole_value());
table->set(value_index, heap_->the_hole_value());
table->ElementRemoved();
}
}
}
@ -2560,70 +2511,6 @@ void MarkCompactCollector::TrimEnumCache(Map* map,
}
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::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()) {
DependentCode::SetMarkedForDeoptimization(
code, static_cast<DependentCode::DependencyGroup>(g));
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;
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);
@ -2699,10 +2586,31 @@ void MarkCompactCollector::ProcessAndClearWeakCells() {
// cannot be a Smi here.
HeapObject* value = HeapObject::cast(weak_cell->value());
if (!MarkCompactCollector::IsMarked(value)) {
weak_cell->clear();
// Cells for new-space objects embedded in optimized code are wrapped in
// WeakCell and put into Heap::weak_object_to_code_table.
// Such cells do not have any strong references but we want to keep them
// alive as long as the cell value is alive.
// TODO(ulan): remove this once we remove Heap::weak_object_to_code_table.
if (value->IsCell()) {
Object* cell_value = Cell::cast(value)->value();
if (cell_value->IsHeapObject() &&
MarkCompactCollector::IsMarked(HeapObject::cast(cell_value))) {
// Resurrect the cell.
MarkBit mark = Marking::MarkBitFrom(value);
SetMark(value, mark);
Object** slot = HeapObject::RawField(value, Cell::kValueOffset);
RecordSlot(slot, slot, *slot);
slot = HeapObject::RawField(weak_cell, WeakCell::kValueOffset);
RecordSlot(slot, slot, *slot);
} else {
weak_cell->clear();
}
} else {
weak_cell->clear();
}
} else {
Object** slot = HeapObject::RawField(weak_cell, WeakCell::kValueOffset);
heap()->mark_compact_collector()->RecordSlot(slot, slot, value);
RecordSlot(slot, slot, *slot);
}
weak_cell_obj = weak_cell->next();
weak_cell->set_next(undefined, SKIP_WRITE_BARRIER);
@ -3548,13 +3456,6 @@ void MarkCompactCollector::EvacuateNewSpaceAndCandidates() {
}
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(
@ -3576,6 +3477,10 @@ void MarkCompactCollector::EvacuateNewSpaceAndCandidates() {
slots_buffer_allocator_.DeallocateChain(&migration_slots_buffer_);
DCHECK(migration_slots_buffer_ == NULL);
// The hashing of weak_object_to_code_table is no longer valid.
heap()->weak_object_to_code_table()->Rehash(
heap()->isolate()->factory()->undefined_value());
}

9
src/heap/mark-compact.h
View File

@ -656,10 +656,6 @@ class MarkCompactCollector {
bool evacuation() const { return evacuation_; }
// Mark the global table which maps weak objects to dependent code without
// marking its contents.
void MarkWeakObjectToCodeTable();
// Special case for processing weak references in a full collection. We need
// to artificially keep AllocationSites alive for a time.
void MarkAllocationSite(AllocationSite* site);
@ -818,11 +814,6 @@ class MarkCompactCollector {
int number_of_own_descriptors);
void TrimEnumCache(Map* map, DescriptorArray* descriptors);
void ClearDependentCode(DependentCode* dependent_code);
void ClearNonLiveDependentCode(DependentCode* dependent_code);
int ClearNonLiveDependentCodeInGroup(DependentCode* dependent_code, int group,
int start, int end, int new_start);
// Mark all values associated with reachable keys in weak collections
// encountered so far. This might push new object or even new weak maps onto
// the marking stack.

35
src/heap/objects-visiting-inl.h
View File

@ -326,19 +326,6 @@ void StaticMarkingVisitor<StaticVisitor>::VisitPropertyCell(
Map* map, HeapObject* object) {
Heap* heap = map->GetHeap();
Object** slot =
HeapObject::RawField(object, PropertyCell::kDependentCodeOffset);
if (FLAG_collect_maps) {
// Mark property cell dependent codes array but do not push it onto marking
// stack, this will make references from it weak. We will clean dead
// codes when we iterate over property cells in ClearNonLiveReferences.
HeapObject* obj = HeapObject::cast(*slot);
heap->mark_compact_collector()->RecordSlot(slot, slot, obj);
StaticVisitor::MarkObjectWithoutPush(heap, obj);
} else {
StaticVisitor::VisitPointer(heap, slot);
}
StaticVisitor::VisitPointers(
heap,
HeapObject::RawField(object, PropertyCell::kPointerFieldsBeginOffset),
@ -367,20 +354,6 @@ void StaticMarkingVisitor<StaticVisitor>::VisitAllocationSite(
Map* map, HeapObject* object) {
Heap* heap = map->GetHeap();
Object** slot =
HeapObject::RawField(object, AllocationSite::kDependentCodeOffset);
if (FLAG_collect_maps) {
// Mark allocation site dependent codes array but do not push it onto
// marking stack, this will make references from it weak. We will clean
// dead codes when we iterate over allocation sites in
// ClearNonLiveReferences.
HeapObject* obj = HeapObject::cast(*slot);
heap->mark_compact_collector()->RecordSlot(slot, slot, obj);
StaticVisitor::MarkObjectWithoutPush(heap, obj);
} else {
StaticVisitor::VisitPointer(heap, slot);
}
StaticVisitor::VisitPointers(
heap,
HeapObject::RawField(object, AllocationSite::kPointerFieldsBeginOffset),
@ -643,14 +616,6 @@ void StaticMarkingVisitor<StaticVisitor>::MarkMapContents(Heap* heap,
descriptors->GetDescriptorEndSlot(end));
}
// Mark prototype dependent codes array but do not push it onto marking
// stack, this will make references from it weak. We will clean dead
// codes when we iterate over maps in ClearNonLiveTransitions.
Object** slot = HeapObject::RawField(map, Map::kDependentCodeOffset);
HeapObject* obj = HeapObject::cast(*slot);
heap->mark_compact_collector()->RecordSlot(slot, slot, obj);
StaticVisitor::MarkObjectWithoutPush(heap, obj);
// Mark the pointer fields of the Map. Since the transitions array has
// been marked already, it is fine that one of these fields contains a
// pointer to it.

11
src/lithium.cc
View File

@ -414,12 +414,12 @@ Representation LChunk::LookupLiteralRepresentation(
static void AddWeakObjectToCodeDependency(Isolate* isolate,
Handle<Object> object,
Handle<HeapObject> object,
Handle<Code> code) {
Handle<WeakCell> cell = Code::WeakCellFor(code);
Heap* heap = isolate->heap();
heap->EnsureWeakObjectToCodeTable();
Handle<DependentCode> dep(heap->LookupWeakObjectToCodeDependency(object));
dep = DependentCode::Insert(dep, DependentCode::kWeakCodeGroup, code);
dep = DependentCode::InsertWeakCode(dep, DependentCode::kWeakCodeGroup, cell);
heap->AddWeakObjectToCodeDependency(object, dep);
}
@ -462,6 +462,9 @@ void LChunk::RegisterWeakObjectsInOptimizedCode(Handle<Code> code) const {
void LChunk::CommitDependencies(Handle<Code> code) const {
if (!code->is_optimized_code()) return;
HandleScope scope(isolate());
for (MapSet::const_iterator it = deprecation_dependencies_.begin(),
iend = deprecation_dependencies_.end(); it != iend; ++it) {
Handle<Map> map = *it;
@ -479,7 +482,7 @@ void LChunk::CommitDependencies(Handle<Code> code) const {
}
info_->CommitDependencies(code);
if (code->is_optimized_code()) RegisterWeakObjectsInOptimizedCode(code);
RegisterWeakObjectsInOptimizedCode(code);
}

13
src/objects-debug.cc
View File

@ -677,6 +677,7 @@ void Code::CodeVerify() {
void Code::VerifyEmbeddedObjectsDependency() {
if (!CanContainWeakObjects()) return;
WeakCell* cell = CachedWeakCell();
DisallowHeapAllocation no_gc;
Isolate* isolate = GetIsolate();
HandleScope scope(isolate);
@ -687,13 +688,13 @@ void Code::VerifyEmbeddedObjectsDependency() {
if (obj->IsMap()) {
Map* map = Map::cast(obj);
CHECK(map->dependent_code()->Contains(DependentCode::kWeakCodeGroup,
this));
cell));
} else if (obj->IsJSObject()) {
Object* raw_table = GetIsolate()->heap()->weak_object_to_code_table();
WeakHashTable* table = WeakHashTable::cast(raw_table);
Handle<Object> key_obj(obj, isolate);
CHECK(DependentCode::cast(table->Lookup(key_obj))->Contains(
DependentCode::kWeakCodeGroup, this));
WeakHashTable* table =
GetIsolate()->heap()->weak_object_to_code_table();
Handle<HeapObject> key_obj(HeapObject::cast(obj), isolate);
CHECK(DependentCode::cast(table->Lookup(key_obj))
->Contains(DependentCode::kWeakCodeGroup, cell));
}
}
}

30
src/objects-inl.h
View File

@ -4766,21 +4766,6 @@ void DependentCode::set_number_of_entries(DependencyGroup group, int value) {
}
bool DependentCode::is_code_at(int i) {
return get(kCodesStartIndex + i)->IsCode();
}
Code* DependentCode::code_at(int i) {
return Code::cast(get(kCodesStartIndex + i));
}
CompilationInfo* DependentCode::compilation_info_at(int i) {
return reinterpret_cast<CompilationInfo*>(
Foreign::cast(get(kCodesStartIndex + i))->foreign_address());
}
void DependentCode::set_object_at(int i, Object* object) {
set(kCodesStartIndex + i, object);
}
@ -4791,11 +4776,6 @@ Object* DependentCode::object_at(int i) {
}
Object** DependentCode::slot_at(int i) {
return RawFieldOfElementAt(kCodesStartIndex + i);
}
void DependentCode::clear_at(int i) {
set_undefined(kCodesStartIndex + i);
}
@ -7228,13 +7208,18 @@ Handle<ObjectHashTable> ObjectHashTable::Shrink(
template <int entrysize>
bool WeakHashTableShape<entrysize>::IsMatch(Handle<Object> key, Object* other) {
return key->SameValue(other);
if (other->IsWeakCell()) other = WeakCell::cast(other)->value();
return key->IsWeakCell() ? WeakCell::cast(*key)->value() == other
: *key == other;
}
template <int entrysize>
uint32_t WeakHashTableShape<entrysize>::Hash(Handle<Object> key) {
intptr_t hash = reinterpret_cast<intptr_t>(*key);
intptr_t hash =
key->IsWeakCell()
? reinterpret_cast<intptr_t>(WeakCell::cast(*key)->value())
: reinterpret_cast<intptr_t>(*key);
return (uint32_t)(hash & 0xFFFFFFFF);
}
@ -7242,6 +7227,7 @@ uint32_t WeakHashTableShape<entrysize>::Hash(Handle<Object> key) {
template <int entrysize>
uint32_t WeakHashTableShape<entrysize>::HashForObject(Handle<Object> key,
Object* other) {
if (other->IsWeakCell()) other = WeakCell::cast(other)->value();
intptr_t hash = reinterpret_cast<intptr_t>(other);
return (uint32_t)(hash & 0xFFFFFFFF);
}

167
src/objects.cc
View File

@ -11884,9 +11884,9 @@ void Map::ZapPrototypeTransitions() {
void Map::AddDependentCompilationInfo(Handle<Map> map,
DependentCode::DependencyGroup group,
CompilationInfo* info) {
Handle<DependentCode> codes =
DependentCode::Insert(handle(map->dependent_code(), info->isolate()),
group, info->object_wrapper());
Handle<DependentCode> codes = DependentCode::InsertCompilationInfo(
handle(map->dependent_code(), info->isolate()), group,
info->object_wrapper());
if (*codes != map->dependent_code()) map->set_dependent_code(*codes);
info->dependencies(group)->Add(map, info->zone());
}
@ -11896,8 +11896,9 @@ void Map::AddDependentCompilationInfo(Handle<Map> map,
void Map::AddDependentCode(Handle<Map> map,
DependentCode::DependencyGroup group,
Handle<Code> code) {
Handle<DependentCode> codes = DependentCode::Insert(
Handle<DependentCode>(map->dependent_code()), group, code);
Handle<WeakCell> cell = Code::WeakCellFor(code);
Handle<DependentCode> codes = DependentCode::InsertWeakCode(
Handle<DependentCode>(map->dependent_code()), group, cell);
if (*codes != map->dependent_code()) map->set_dependent_code(*codes);
}
@ -11929,6 +11930,20 @@ DependentCode* DependentCode::ForObject(Handle<HeapObject> object,
}
Handle<DependentCode> DependentCode::InsertCompilationInfo(
Handle<DependentCode> entries, DependencyGroup group,
Handle<Foreign> info) {
return Insert(entries, group, info);
}
Handle<DependentCode> DependentCode::InsertWeakCode(
Handle<DependentCode> entries, DependencyGroup group,
Handle<WeakCell> code_cell) {
return Insert(entries, group, code_cell);
}
Handle<DependentCode> DependentCode::Insert(Handle<DependentCode> entries,
DependencyGroup group,
Handle<Object> object) {
@ -11941,27 +11956,13 @@ Handle<DependentCode> DependentCode::Insert(Handle<DependentCode> entries,
if (entries->object_at(i) == *object) return entries;
}
if (entries->length() < kCodesStartIndex + number_of_entries + 1) {
int capacity = kCodesStartIndex + number_of_entries + 1;
if (capacity > 5) capacity = capacity * 5 / 4;
Handle<DependentCode> new_entries = Handle<DependentCode>::cast(
FixedArray::CopySize(entries, capacity, TENURED));
// The number of codes can change after GC.
entries = EnsureSpace(entries);
// The number of codes can change after Compact and GC.
starts.Recompute(*entries);
start = starts.at(group);
end = starts.at(group + 1);
number_of_entries = starts.number_of_entries();
for (int i = 0; i < number_of_entries; i++) {
entries->clear_at(i);
}
// If the old fixed array was empty, we need to reset counters of the
// new array.
if (number_of_entries == 0) {
for (int g = 0; g < kGroupCount; g++) {
new_entries->set_number_of_entries(static_cast<DependencyGroup>(g), 0);
}
}
entries = new_entries;
}
entries->ExtendGroup(group);
entries->set_object_at(end, *object);
entries->set_number_of_entries(group, end + 1 - start);
@ -11969,42 +11970,82 @@ Handle<DependentCode> DependentCode::Insert(Handle<DependentCode> entries,
}
void DependentCode::UpdateToFinishedCode(DependencyGroup group,
CompilationInfo* info,
Code* code) {
Handle<DependentCode> DependentCode::EnsureSpace(
Handle<DependentCode> entries) {
if (entries->length() == 0) {
entries = Handle<DependentCode>::cast(
FixedArray::CopySize(entries, kCodesStartIndex + 1, TENURED));
for (int g = 0; g < kGroupCount; g++) {
entries->set_number_of_entries(static_cast<DependencyGroup>(g), 0);
}
return entries;
}
if (entries->Compact()) return entries;
GroupStartIndexes starts(*entries);
int capacity =
kCodesStartIndex + DependentCode::Grow(starts.number_of_entries());
return Handle<DependentCode>::cast(
FixedArray::CopySize(entries, capacity, TENURED));
}
bool DependentCode::Compact() {
GroupStartIndexes starts(this);
int n = 0;
for (int g = 0; g < kGroupCount; g++) {
int start = starts.at(g);
int end = starts.at(g + 1);
int count = 0;
DCHECK(start >= n);
for (int i = start; i < end; i++) {
Object* obj = object_at(i);
if (!obj->IsWeakCell() || !WeakCell::cast(obj)->cleared()) {
if (i != n + count) {
copy(i, n + count);
}
count++;
}
}
if (count != end - start) {
set_number_of_entries(static_cast<DependencyGroup>(g), count);
}
n += count;
}
return n < starts.number_of_entries();
}
void DependentCode::UpdateToFinishedCode(DependencyGroup group, Foreign* info,
WeakCell* code_cell) {
DisallowHeapAllocation no_gc;
AllowDeferredHandleDereference get_object_wrapper;
Foreign* info_wrapper = *info->object_wrapper();
GroupStartIndexes starts(this);
int start = starts.at(group);
int end = starts.at(group + 1);
for (int i = start; i < end; i++) {
if (object_at(i) == info_wrapper) {
set_object_at(i, code);
if (object_at(i) == info) {
set_object_at(i, code_cell);
break;
}
}
#ifdef DEBUG
for (int i = start; i < end; i++) {
DCHECK(is_code_at(i) || compilation_info_at(i) != info);
DCHECK(object_at(i) != info);
}
#endif
}
void DependentCode::RemoveCompilationInfo(DependentCode::DependencyGroup group,
CompilationInfo* info) {
Foreign* info) {
DisallowHeapAllocation no_allocation;
AllowDeferredHandleDereference get_object_wrapper;
Foreign* info_wrapper = *info->object_wrapper();
GroupStartIndexes starts(this);
int start = starts.at(group);
int end = starts.at(group + 1);
// Find compilation info wrapper.
int info_pos = -1;
for (int i = start; i < end; i++) {
if (object_at(i) == info_wrapper) {
if (object_at(i) == info) {
info_pos = i;
break;
}
@ -12025,18 +12066,18 @@ void DependentCode::RemoveCompilationInfo(DependentCode::DependencyGroup group,
#ifdef DEBUG
for (int i = start; i < end - 1; i++) {
DCHECK(is_code_at(i) || compilation_info_at(i) != info);
DCHECK(object_at(i) != info);
}
#endif
}
bool DependentCode::Contains(DependencyGroup group, Code* code) {
bool DependentCode::Contains(DependencyGroup group, WeakCell* code_cell) {
GroupStartIndexes starts(this);
int start = starts.at(group);
int end = starts.at(group + 1);
for (int i = start; i < end; i++) {
if (object_at(i) == code) return true;
if (object_at(i) == code_cell) return true;
}
return false;
}
@ -12054,15 +12095,24 @@ bool DependentCode::MarkCodeForDeoptimization(
// Mark all the code that needs to be deoptimized.
bool marked = false;
bool invalidate_embedded_objects = group == kWeakCodeGroup;
for (int i = start; i < end; i++) {
if (is_code_at(i)) {
Code* code = code_at(i);
Object* obj = object_at(i);
if (obj->IsWeakCell()) {
WeakCell* cell = WeakCell::cast(obj);
if (cell->cleared()) continue;
Code* code = Code::cast(cell->value());
if (!code->marked_for_deoptimization()) {
SetMarkedForDeoptimization(code, group);
if (invalidate_embedded_objects) {
code->InvalidateEmbeddedObjects();
}
marked = true;
}
} else {
CompilationInfo* info = compilation_info_at(i);
DCHECK(obj->IsForeign());
CompilationInfo* info = reinterpret_cast<CompilationInfo*>(
Foreign::cast(obj)->foreign_address());
info->AbortDueToDependencyChange();
}
}
@ -12086,7 +12136,6 @@ void DependentCode::DeoptimizeDependentCodeGroup(
DCHECK(AllowCodeDependencyChange::IsAllowed());
DisallowHeapAllocation no_allocation_scope;
bool marked = MarkCodeForDeoptimization(isolate, group);
if (marked) Deoptimizer::DeoptimizeMarkedCode(isolate);
}
@ -13167,7 +13216,7 @@ void AllocationSite::AddDependentCompilationInfo(
CompilationInfo* info) {
Handle<DependentCode> dep(site->dependent_code());
Handle<DependentCode> codes =
DependentCode::Insert(dep, group, info->object_wrapper());
DependentCode::InsertCompilationInfo(dep, group, info->object_wrapper());
if (*codes != site->dependent_code()) site->set_dependent_code(*codes);
info->dependencies(group)->Add(Handle<HeapObject>(*site), info->zone());
}
@ -15980,7 +16029,7 @@ void ObjectHashTable::RemoveEntry(int entry) {
}
Object* WeakHashTable::Lookup(Handle<Object> key) {
Object* WeakHashTable::Lookup(Handle<HeapObject> key) {
DisallowHeapAllocation no_gc;
DCHECK(IsKey(*key));
int entry = FindEntry(key);
@ -15990,36 +16039,31 @@ Object* WeakHashTable::Lookup(Handle<Object> key) {
Handle<WeakHashTable> WeakHashTable::Put(Handle<WeakHashTable> table,
Handle<Object> key,
Handle<Object> value) {
Handle<HeapObject> key,
Handle<HeapObject> value) {
DCHECK(table->IsKey(*key));
int entry = table->FindEntry(key);
// Key is already in table, just overwrite value.
if (entry != kNotFound) {
// TODO(ulan): Skipping write barrier is a temporary solution to avoid
// memory leaks. Remove this once we have special visitor for weak fixed
// arrays.
table->set(EntryToValueIndex(entry), *value, SKIP_WRITE_BARRIER);
table->set(EntryToValueIndex(entry), *value);
return table;
}
Handle<WeakCell> key_cell = key->GetIsolate()->factory()->NewWeakCell(key);
// Check whether the hash table should be extended.
table = EnsureCapacity(table, 1, key, TENURED);
table->AddEntry(table->FindInsertionEntry(table->Hash(key)), key, value);
table->AddEntry(table->FindInsertionEntry(table->Hash(key)), key_cell, value);
return table;
}
void WeakHashTable::AddEntry(int entry,
Handle<Object> key,
Handle<Object> value) {
void WeakHashTable::AddEntry(int entry, Handle<WeakCell> key_cell,
Handle<HeapObject> value) {
DisallowHeapAllocation no_allocation;
// TODO(ulan): Skipping write barrier is a temporary solution to avoid
// memory leaks. Remove this once we have special visitor for weak fixed
// arrays.
set(EntryToIndex(entry), *key, SKIP_WRITE_BARRIER);
set(EntryToValueIndex(entry), *value, SKIP_WRITE_BARRIER);
set(EntryToIndex(entry), *key_cell);
set(EntryToValueIndex(entry), *value);
ElementAdded();
}
@ -16962,10 +17006,9 @@ Handle<Object> PropertyCell::SetValueInferType(Handle<PropertyCell> cell,
// static
void PropertyCell::AddDependentCompilationInfo(Handle<PropertyCell> cell,
CompilationInfo* info) {
Handle<DependentCode> codes =
DependentCode::Insert(handle(cell->dependent_code(), info->isolate()),
DependentCode::kPropertyCellChangedGroup,
info->object_wrapper());
Handle<DependentCode> codes = DependentCode::InsertCompilationInfo(
handle(cell->dependent_code(), info->isolate()),
DependentCode::kPropertyCellChangedGroup, info->object_wrapper());
if (*codes != cell->dependent_code()) cell->set_dependent_code(*codes);
info->dependencies(DependentCode::kPropertyCellChangedGroup)->Add(
cell, info->zone());

74
src/objects.h
View File

@ -850,6 +850,7 @@ class ConsString;
class DictionaryElementsAccessor;
class ElementsAccessor;
class FixedArrayBase;
class FunctionLiteral;
class GlobalObject;
class LayoutDescriptor;
class LookupIterator;
@ -857,7 +858,6 @@ class ObjectVisitor;
class StringStream;
class TypeFeedbackVector;
class WeakCell;
class FunctionLiteral;
// We cannot just say "class HeapType;" if it is created from a template... =8-?
template<class> class TypeImpl;
@ -4049,9 +4049,9 @@ class WeakHashTableShape : public BaseShape<Handle<Object> > {
};
// WeakHashTable maps keys that are arbitrary objects to object values.
// It is used for the global weak hash table that maps objects
// embedded in optimized code to dependent code lists.
// WeakHashTable maps keys that are arbitrary heap objects to heap object
// values. The table wraps the keys in weak cells and store values directly.
// Thus it references keys weakly and values strongly.
class WeakHashTable: public HashTable<WeakHashTable,
WeakHashTableShape<2>,
Handle<Object> > {
@ -4062,27 +4062,18 @@ class WeakHashTable: public HashTable<WeakHashTable,
// Looks up the value associated with the given key. The hole value is
// returned in case the key is not present.
Object* Lookup(Handle<Object> key);
Object* Lookup(Handle<HeapObject> key);
// Adds (or overwrites) the value associated with the given key. Mapping a
// key to the hole value causes removal of the whole entry.
MUST_USE_RESULT static Handle<WeakHashTable> Put(Handle<WeakHashTable> table,
Handle<Object> key,
Handle<Object> value);
// This function is called when heap verification is turned on.
void Zap(Object* value) {
int capacity = Capacity();
for (int i = 0; i < capacity; i++) {
set(EntryToIndex(i), value);
set(EntryToValueIndex(i), value);
}
}
Handle<HeapObject> key,
Handle<HeapObject> value);
private:
friend class MarkCompactCollector;
void AddEntry(int entry, Handle<Object> key, Handle<Object> value);
void AddEntry(int entry, Handle<WeakCell> key, Handle<HeapObject> value);
// Returns the index to the value of an entry.
static inline int EntryToValueIndex(int entry) {
@ -5543,9 +5534,9 @@ class CompilationInfo;
//
// The first n elements are Smis, each of them specifies the number of codes
// in the corresponding group. The subsequent elements contain grouped code
// objects. The suffix of the array can be filled with the undefined value if
// the number of codes is less than the length of the array. The order of the
// code objects within a group is not preserved.
// objects in weak cells. The suffix of the array can be filled with the
// undefined value if the number of codes is less than the length of the
// array. The order of the code objects within a group is not preserved.
//
// All code indexes used in the class are counted starting from the first
// code object of the first group. In other words, code index 0 corresponds
@ -5599,15 +5590,21 @@ class DependentCode: public FixedArray {
int start_indexes_[kGroupCount + 1];
};
bool Contains(DependencyGroup group, Code* code);
static Handle<DependentCode> Insert(Handle<DependentCode> entries,
DependencyGroup group,
Handle<Object> object);
void UpdateToFinishedCode(DependencyGroup group,
CompilationInfo* info,
Code* code);
bool Contains(DependencyGroup group, WeakCell* code_cell);
static Handle<DependentCode> InsertCompilationInfo(
Handle<DependentCode> entries, DependencyGroup group,
Handle<Foreign> info);
static Handle<DependentCode> InsertWeakCode(Handle<DependentCode> entries,
DependencyGroup group,
Handle<WeakCell> code_cell);
void UpdateToFinishedCode(DependencyGroup group, Foreign* info,
WeakCell* code_cell);
void RemoveCompilationInfo(DependentCode::DependencyGroup group,
CompilationInfo* info);
Foreign* info);
void DeoptimizeDependentCodeGroup(Isolate* isolate,
DependentCode::DependencyGroup group);
@ -5619,12 +5616,8 @@ class DependentCode: public FixedArray {
// and the mark compact collector.
inline int number_of_entries(DependencyGroup group);
inline void set_number_of_entries(DependencyGroup group, int value);
inline bool is_code_at(int i);
inline Code* code_at(int i);
inline CompilationInfo* compilation_info_at(int i);
inline void set_object_at(int i, Object* object);
inline Object** slot_at(int i);
inline Object* object_at(int i);
inline void set_object_at(int i, Object* object);
inline void clear_at(int i);
inline void copy(int from, int to);
DECLARE_CAST(DependentCode)
@ -5636,9 +5629,20 @@ class DependentCode: public FixedArray {
static void SetMarkedForDeoptimization(Code* code, DependencyGroup group);
private:
static Handle<DependentCode> Insert(Handle<DependentCode> entries,
DependencyGroup group,
Handle<Object> object);
static Handle<DependentCode> EnsureSpace(Handle<DependentCode> entries);
// Make a room at the end of the given group by moving out the first
// code objects of the subsequent groups.
inline void ExtendGroup(DependencyGroup group);
// Compact by removing cleared weak cells and return true if there was
// any cleared weak cell.
bool Compact();
static int Grow(int number_of_entries) {
if (number_of_entries < 5) return number_of_entries + 1;
return number_of_entries * 5 / 4;
}
static const int kCodesStartIndex = kGroupCount;
};
@ -8473,7 +8477,7 @@ class AllocationSite: public Struct {
// During mark compact we need to take special care for the dependent code
// field.
static const int kPointerFieldsBeginOffset = kTransitionInfoOffset;
static const int kPointerFieldsEndOffset = kDependentCodeOffset;
static const int kPointerFieldsEndOffset = kWeakNextOffset;
// For other visitors, use the fixed body descriptor below.
typedef FixedBodyDescriptor<HeapObject::kHeaderSize,
@ -9741,7 +9745,7 @@ class PropertyCell: public Cell {
static const int kSize = kDependentCodeOffset + kPointerSize;
static const int kPointerFieldsBeginOffset = kValueOffset;
static const int kPointerFieldsEndOffset = kDependentCodeOffset;
static const int kPointerFieldsEndOffset = kSize;
typedef FixedBodyDescriptor<kValueOffset,
kSize,

2
src/serialize.cc
View File

@ -682,8 +682,6 @@ void Deserializer::Deserialize(Isolate* isolate) {
isolate_->heap()->undefined_value());
}
isolate_->heap()->InitializeWeakObjectToCodeTable();
// Update data pointers to the external strings containing natives sources.
for (int i = 0; i < Natives::GetBuiltinsCount(); i++) {
Object* source = isolate_->heap()->natives_source_cache()->get(i);

8
test/cctest/test-heap.cc
View File

@ -4068,8 +4068,9 @@ TEST(EnsureAllocationSiteDependentCodesProcessed) {
DependentCode::GroupStartIndexes starts(site->dependent_code());
CHECK_GE(starts.number_of_entries(), 1);
int index = starts.at(DependentCode::kAllocationSiteTransitionChangedGroup);
CHECK(site->dependent_code()->is_code_at(index));
Code* function_bar = site->dependent_code()->code_at(index);
CHECK(site->dependent_code()->object_at(index)->IsWeakCell());
Code* function_bar = Code::cast(
WeakCell::cast(site->dependent_code()->object_at(index))->value());
Handle<JSFunction> bar_handle =
v8::Utils::OpenHandle(
*v8::Handle<v8::Function>::Cast(
@ -4087,7 +4088,8 @@ TEST(EnsureAllocationSiteDependentCodesProcessed) {
// longer referred to by dependent_code().
DependentCode::GroupStartIndexes starts(site->dependent_code());
int index = starts.at(DependentCode::kAllocationSiteTransitionChangedGroup);
CHECK(!(site->dependent_code()->is_code_at(index)));
CHECK(site->dependent_code()->object_at(index)->IsWeakCell() &&
WeakCell::cast(site->dependent_code()->object_at(index))->cleared());
}