| // Copyright 2011 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/heap/objects-visiting.h" |
| #include "src/ic-inl.h" |
| |
| namespace v8 { |
| namespace internal { |
| |
| |
| StaticVisitorBase::VisitorId StaticVisitorBase::GetVisitorId( |
| int instance_type, int instance_size) { |
| if (instance_type < FIRST_NONSTRING_TYPE) { |
| switch (instance_type & kStringRepresentationMask) { |
| case kSeqStringTag: |
| if ((instance_type & kStringEncodingMask) == kOneByteStringTag) { |
| return kVisitSeqOneByteString; |
| } else { |
| return kVisitSeqTwoByteString; |
| } |
| |
| case kConsStringTag: |
| if (IsShortcutCandidate(instance_type)) { |
| return kVisitShortcutCandidate; |
| } else { |
| return kVisitConsString; |
| } |
| |
| case kSlicedStringTag: |
| return kVisitSlicedString; |
| |
| case kExternalStringTag: |
| return GetVisitorIdForSize(kVisitDataObject, kVisitDataObjectGeneric, |
| instance_size); |
| } |
| UNREACHABLE(); |
| } |
| |
| switch (instance_type) { |
| case BYTE_ARRAY_TYPE: |
| return kVisitByteArray; |
| |
| case FREE_SPACE_TYPE: |
| return kVisitFreeSpace; |
| |
| case FIXED_ARRAY_TYPE: |
| return kVisitFixedArray; |
| |
| case FIXED_DOUBLE_ARRAY_TYPE: |
| return kVisitFixedDoubleArray; |
| |
| case CONSTANT_POOL_ARRAY_TYPE: |
| return kVisitConstantPoolArray; |
| |
| case ODDBALL_TYPE: |
| return kVisitOddball; |
| |
| case MAP_TYPE: |
| return kVisitMap; |
| |
| case CODE_TYPE: |
| return kVisitCode; |
| |
| case CELL_TYPE: |
| return kVisitCell; |
| |
| case PROPERTY_CELL_TYPE: |
| return kVisitPropertyCell; |
| |
| case JS_SET_TYPE: |
| return GetVisitorIdForSize(kVisitStruct, kVisitStructGeneric, |
| JSSet::kSize); |
| |
| case JS_MAP_TYPE: |
| return GetVisitorIdForSize(kVisitStruct, kVisitStructGeneric, |
| JSMap::kSize); |
| |
| case JS_WEAK_MAP_TYPE: |
| case JS_WEAK_SET_TYPE: |
| return kVisitJSWeakCollection; |
| |
| case JS_REGEXP_TYPE: |
| return kVisitJSRegExp; |
| |
| case SHARED_FUNCTION_INFO_TYPE: |
| return kVisitSharedFunctionInfo; |
| |
| case JS_PROXY_TYPE: |
| return GetVisitorIdForSize(kVisitStruct, kVisitStructGeneric, |
| JSProxy::kSize); |
| |
| case JS_FUNCTION_PROXY_TYPE: |
| return GetVisitorIdForSize(kVisitStruct, kVisitStructGeneric, |
| JSFunctionProxy::kSize); |
| |
| case FOREIGN_TYPE: |
| return GetVisitorIdForSize(kVisitDataObject, kVisitDataObjectGeneric, |
| Foreign::kSize); |
| |
| case SYMBOL_TYPE: |
| return kVisitSymbol; |
| |
| case FILLER_TYPE: |
| return kVisitDataObjectGeneric; |
| |
| case JS_ARRAY_BUFFER_TYPE: |
| return kVisitJSArrayBuffer; |
| |
| case JS_TYPED_ARRAY_TYPE: |
| return kVisitJSTypedArray; |
| |
| case JS_DATA_VIEW_TYPE: |
| return kVisitJSDataView; |
| |
| case JS_OBJECT_TYPE: |
| case JS_CONTEXT_EXTENSION_OBJECT_TYPE: |
| case JS_GENERATOR_OBJECT_TYPE: |
| case JS_MODULE_TYPE: |
| case JS_VALUE_TYPE: |
| case JS_DATE_TYPE: |
| case JS_ARRAY_TYPE: |
| case JS_GLOBAL_PROXY_TYPE: |
| case JS_GLOBAL_OBJECT_TYPE: |
| case JS_BUILTINS_OBJECT_TYPE: |
| case JS_MESSAGE_OBJECT_TYPE: |
| case JS_SET_ITERATOR_TYPE: |
| case JS_MAP_ITERATOR_TYPE: |
| return GetVisitorIdForSize(kVisitJSObject, kVisitJSObjectGeneric, |
| instance_size); |
| |
| case JS_FUNCTION_TYPE: |
| return kVisitJSFunction; |
| |
| case HEAP_NUMBER_TYPE: |
| case MUTABLE_HEAP_NUMBER_TYPE: |
| #define EXTERNAL_ARRAY_CASE(Type, type, TYPE, ctype, size) \ |
| case EXTERNAL_##TYPE##_ARRAY_TYPE: |
| |
| TYPED_ARRAYS(EXTERNAL_ARRAY_CASE) |
| return GetVisitorIdForSize(kVisitDataObject, kVisitDataObjectGeneric, |
| instance_size); |
| #undef EXTERNAL_ARRAY_CASE |
| |
| case FIXED_UINT8_ARRAY_TYPE: |
| case FIXED_INT8_ARRAY_TYPE: |
| case FIXED_UINT16_ARRAY_TYPE: |
| case FIXED_INT16_ARRAY_TYPE: |
| case FIXED_UINT32_ARRAY_TYPE: |
| case FIXED_INT32_ARRAY_TYPE: |
| case FIXED_FLOAT32_ARRAY_TYPE: |
| case FIXED_UINT8_CLAMPED_ARRAY_TYPE: |
| return kVisitFixedTypedArray; |
| |
| case FIXED_FLOAT64_ARRAY_TYPE: |
| return kVisitFixedFloat64Array; |
| |
| #define MAKE_STRUCT_CASE(NAME, Name, name) case NAME##_TYPE: |
| STRUCT_LIST(MAKE_STRUCT_CASE) |
| #undef MAKE_STRUCT_CASE |
| if (instance_type == ALLOCATION_SITE_TYPE) { |
| return kVisitAllocationSite; |
| } |
| |
| return GetVisitorIdForSize(kVisitStruct, kVisitStructGeneric, |
| instance_size); |
| |
| default: |
| UNREACHABLE(); |
| return kVisitorIdCount; |
| } |
| } |
| |
| |
| // We don't record weak slots during marking or scavenges. Instead we do it |
| // once when we complete mark-compact cycle. Note that write barrier has no |
| // effect if we are already in the middle of compacting mark-sweep cycle and we |
| // have to record slots manually. |
| static bool MustRecordSlots(Heap* heap) { |
| return heap->gc_state() == Heap::MARK_COMPACT && |
| heap->mark_compact_collector()->is_compacting(); |
| } |
| |
| |
| template <class T> |
| struct WeakListVisitor; |
| |
| |
| template <class T> |
| Object* VisitWeakList(Heap* heap, Object* list, WeakObjectRetainer* retainer) { |
| Object* undefined = heap->undefined_value(); |
| Object* head = undefined; |
| T* tail = NULL; |
| MarkCompactCollector* collector = heap->mark_compact_collector(); |
| bool record_slots = MustRecordSlots(heap); |
| while (list != undefined) { |
| // Check whether to keep the candidate in the list. |
| T* candidate = reinterpret_cast<T*>(list); |
| Object* retained = retainer->RetainAs(list); |
| if (retained != NULL) { |
| if (head == undefined) { |
| // First element in the list. |
| head = retained; |
| } else { |
| // Subsequent elements in the list. |
| DCHECK(tail != NULL); |
| WeakListVisitor<T>::SetWeakNext(tail, retained); |
| if (record_slots) { |
| Object** next_slot = |
| HeapObject::RawField(tail, WeakListVisitor<T>::WeakNextOffset()); |
| collector->RecordSlot(next_slot, next_slot, retained); |
| } |
| } |
| // Retained object is new tail. |
| DCHECK(!retained->IsUndefined()); |
| candidate = reinterpret_cast<T*>(retained); |
| tail = candidate; |
| |
| |
| // tail is a live object, visit it. |
| WeakListVisitor<T>::VisitLiveObject(heap, tail, retainer); |
| } else { |
| WeakListVisitor<T>::VisitPhantomObject(heap, candidate); |
| } |
| |
| // Move to next element in the list. |
| list = WeakListVisitor<T>::WeakNext(candidate); |
| } |
| |
| // Terminate the list if there is one or more elements. |
| if (tail != NULL) { |
| WeakListVisitor<T>::SetWeakNext(tail, undefined); |
| } |
| return head; |
| } |
| |
| |
| template <class T> |
| static void ClearWeakList(Heap* heap, Object* list) { |
| Object* undefined = heap->undefined_value(); |
| while (list != undefined) { |
| T* candidate = reinterpret_cast<T*>(list); |
| list = WeakListVisitor<T>::WeakNext(candidate); |
| WeakListVisitor<T>::SetWeakNext(candidate, undefined); |
| } |
| } |
| |
| |
| template <> |
| struct WeakListVisitor<JSFunction> { |
| static void SetWeakNext(JSFunction* function, Object* next) { |
| function->set_next_function_link(next); |
| } |
| |
| static Object* WeakNext(JSFunction* function) { |
| return function->next_function_link(); |
| } |
| |
| static int WeakNextOffset() { return JSFunction::kNextFunctionLinkOffset; } |
| |
| static void VisitLiveObject(Heap*, JSFunction*, WeakObjectRetainer*) {} |
| |
| static void VisitPhantomObject(Heap*, JSFunction*) {} |
| }; |
| |
| |
| template <> |
| struct WeakListVisitor<Code> { |
| static void SetWeakNext(Code* code, Object* next) { |
| code->set_next_code_link(next); |
| } |
| |
| static Object* WeakNext(Code* code) { return code->next_code_link(); } |
| |
| static int WeakNextOffset() { return Code::kNextCodeLinkOffset; } |
| |
| static void VisitLiveObject(Heap*, Code*, WeakObjectRetainer*) {} |
| |
| static void VisitPhantomObject(Heap*, Code*) {} |
| }; |
| |
| |
| template <> |
| struct WeakListVisitor<Context> { |
| static void SetWeakNext(Context* context, Object* next) { |
| context->set(Context::NEXT_CONTEXT_LINK, next, UPDATE_WRITE_BARRIER); |
| } |
| |
| static Object* WeakNext(Context* context) { |
| return context->get(Context::NEXT_CONTEXT_LINK); |
| } |
| |
| static int WeakNextOffset() { |
| return FixedArray::SizeFor(Context::NEXT_CONTEXT_LINK); |
| } |
| |
| static void VisitLiveObject(Heap* heap, Context* context, |
| WeakObjectRetainer* retainer) { |
| // Process the three weak lists linked off the context. |
| DoWeakList<JSFunction>(heap, context, retainer, |
| Context::OPTIMIZED_FUNCTIONS_LIST); |
| DoWeakList<Code>(heap, context, retainer, Context::OPTIMIZED_CODE_LIST); |
| DoWeakList<Code>(heap, context, retainer, Context::DEOPTIMIZED_CODE_LIST); |
| } |
| |
| template <class T> |
| static void DoWeakList(Heap* heap, Context* context, |
| WeakObjectRetainer* retainer, int index) { |
| // Visit the weak list, removing dead intermediate elements. |
| Object* list_head = VisitWeakList<T>(heap, context->get(index), retainer); |
| |
| // Update the list head. |
| context->set(index, list_head, UPDATE_WRITE_BARRIER); |
| |
| if (MustRecordSlots(heap)) { |
| // Record the updated slot if necessary. |
| Object** head_slot = |
| HeapObject::RawField(context, FixedArray::SizeFor(index)); |
| heap->mark_compact_collector()->RecordSlot(head_slot, head_slot, |
| list_head); |
| } |
| } |
| |
| static void VisitPhantomObject(Heap* heap, Context* context) { |
| ClearWeakList<JSFunction>(heap, |
| context->get(Context::OPTIMIZED_FUNCTIONS_LIST)); |
| ClearWeakList<Code>(heap, context->get(Context::OPTIMIZED_CODE_LIST)); |
| ClearWeakList<Code>(heap, context->get(Context::DEOPTIMIZED_CODE_LIST)); |
| } |
| }; |
| |
| |
| template <> |
| struct WeakListVisitor<JSArrayBufferView> { |
| static void SetWeakNext(JSArrayBufferView* obj, Object* next) { |
| obj->set_weak_next(next); |
| } |
| |
| static Object* WeakNext(JSArrayBufferView* obj) { return obj->weak_next(); } |
| |
| static int WeakNextOffset() { return JSArrayBufferView::kWeakNextOffset; } |
| |
| static void VisitLiveObject(Heap*, JSArrayBufferView*, WeakObjectRetainer*) {} |
| |
| static void VisitPhantomObject(Heap*, JSArrayBufferView*) {} |
| }; |
| |
| |
| template <> |
| struct WeakListVisitor<JSArrayBuffer> { |
| static void SetWeakNext(JSArrayBuffer* obj, Object* next) { |
| obj->set_weak_next(next); |
| } |
| |
| static Object* WeakNext(JSArrayBuffer* obj) { return obj->weak_next(); } |
| |
| static int WeakNextOffset() { return JSArrayBuffer::kWeakNextOffset; } |
| |
| static void VisitLiveObject(Heap* heap, JSArrayBuffer* array_buffer, |
| WeakObjectRetainer* retainer) { |
| Object* typed_array_obj = VisitWeakList<JSArrayBufferView>( |
| heap, array_buffer->weak_first_view(), retainer); |
| array_buffer->set_weak_first_view(typed_array_obj); |
| if (typed_array_obj != heap->undefined_value() && MustRecordSlots(heap)) { |
| Object** slot = HeapObject::RawField(array_buffer, |
| JSArrayBuffer::kWeakFirstViewOffset); |
| heap->mark_compact_collector()->RecordSlot(slot, slot, typed_array_obj); |
| } |
| } |
| |
| static void VisitPhantomObject(Heap* heap, JSArrayBuffer* phantom) { |
| Runtime::FreeArrayBuffer(heap->isolate(), phantom); |
| } |
| }; |
| |
| |
| template <> |
| struct WeakListVisitor<AllocationSite> { |
| static void SetWeakNext(AllocationSite* obj, Object* next) { |
| obj->set_weak_next(next); |
| } |
| |
| static Object* WeakNext(AllocationSite* obj) { return obj->weak_next(); } |
| |
| static int WeakNextOffset() { return AllocationSite::kWeakNextOffset; } |
| |
| static void VisitLiveObject(Heap*, AllocationSite*, WeakObjectRetainer*) {} |
| |
| static void VisitPhantomObject(Heap*, AllocationSite*) {} |
| }; |
| |
| |
| template Object* VisitWeakList<Code>(Heap* heap, Object* list, |
| WeakObjectRetainer* retainer); |
| |
| |
| template Object* VisitWeakList<JSFunction>(Heap* heap, Object* list, |
| WeakObjectRetainer* retainer); |
| |
| |
| template Object* VisitWeakList<Context>(Heap* heap, Object* list, |
| WeakObjectRetainer* retainer); |
| |
| |
| template Object* VisitWeakList<JSArrayBuffer>(Heap* heap, Object* list, |
| WeakObjectRetainer* retainer); |
| |
| |
| template Object* VisitWeakList<AllocationSite>(Heap* heap, Object* list, |
| WeakObjectRetainer* retainer); |
| } |
| } // namespace v8::internal |