| // Copyright 2018 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. |
| |
| #ifndef V8_OBJECTS_JS_WEAK_REFS_H_ |
| #define V8_OBJECTS_JS_WEAK_REFS_H_ |
| |
| #include "src/objects/js-objects.h" |
| |
| // Has to be the last include (doesn't have include guards): |
| #include "src/objects/object-macros.h" |
| |
| namespace v8 { |
| namespace internal { |
| |
| class JSWeakCell; |
| |
| // WeakFactory object from the JS Weak Refs spec proposal: |
| // https://github.com/tc39/proposal-weakrefs |
| class JSWeakFactory : public JSObject { |
| public: |
| DECL_PRINTER(JSWeakFactory) |
| DECL_VERIFIER(JSWeakFactory) |
| DECL_CAST(JSWeakFactory) |
| |
| DECL_ACCESSORS(cleanup, Object) |
| DECL_ACCESSORS(active_cells, Object) |
| DECL_ACCESSORS(cleared_cells, Object) |
| |
| // For storing a list of JSWeakFactory objects in NativeContext. |
| DECL_ACCESSORS(next, Object) |
| |
| DECL_INT_ACCESSORS(flags) |
| |
| // Adds a newly constructed JSWeakCell object into this JSWeakFactory. |
| inline void AddWeakCell(JSWeakCell* weak_cell); |
| |
| // Returns true if the cleared_cells list is non-empty. |
| inline bool NeedsCleanup() const; |
| |
| inline bool scheduled_for_cleanup() const; |
| inline void set_scheduled_for_cleanup(bool scheduled_for_cleanup); |
| |
| // Get and remove the first cleared JSWeakCell from the cleared_cells |
| // list. (Assumes there is one.) |
| inline JSWeakCell* PopClearedCell(Isolate* isolate); |
| |
| static const int kCleanupOffset = JSObject::kHeaderSize; |
| static const int kActiveCellsOffset = kCleanupOffset + kPointerSize; |
| static const int kClearedCellsOffset = kActiveCellsOffset + kPointerSize; |
| static const int kNextOffset = kClearedCellsOffset + kPointerSize; |
| static const int kFlagsOffset = kNextOffset + kPointerSize; |
| static const int kSize = kFlagsOffset + kPointerSize; |
| |
| // Bitfields in flags. |
| class ScheduledForCleanupField : public BitField<bool, 0, 1> {}; |
| |
| static void CleanupJSWeakFactoriesCallback(void* data); |
| |
| private: |
| DISALLOW_IMPLICIT_CONSTRUCTORS(JSWeakFactory); |
| }; |
| |
| // WeakCell object from the JS Weak Refs spec proposal. |
| class JSWeakCell : public JSObject { |
| public: |
| DECL_PRINTER(JSWeakCell) |
| DECL_VERIFIER(JSWeakCell) |
| DECL_CAST(JSWeakCell) |
| |
| DECL_ACCESSORS(factory, Object) |
| DECL_ACCESSORS(target, Object) |
| DECL_ACCESSORS(holdings, Object) |
| |
| // For storing doubly linked lists of JSWeakCells in JSWeakFactory. |
| DECL_ACCESSORS(prev, Object) |
| DECL_ACCESSORS(next, Object) |
| |
| static const int kFactoryOffset = JSObject::kHeaderSize; |
| static const int kTargetOffset = kFactoryOffset + kPointerSize; |
| static const int kHoldingsOffset = kTargetOffset + kPointerSize; |
| static const int kPrevOffset = kHoldingsOffset + kPointerSize; |
| static const int kNextOffset = kPrevOffset + kPointerSize; |
| static const int kSize = kNextOffset + kPointerSize; |
| |
| class BodyDescriptor; |
| |
| // Nullify is called during GC and it modifies the pointers in JSWeakCell and |
| // JSWeakFactory. Thus we need to tell the GC about the modified slots via the |
| // gc_notify_updated_slot function. The normal write barrier is not enough, |
| // since it's disabled before GC. |
| inline void Nullify( |
| Isolate* isolate, |
| std::function<void(HeapObject* object, ObjectSlot slot, Object* target)> |
| gc_notify_updated_slot); |
| |
| inline void Clear(Isolate* isolate); |
| |
| private: |
| DISALLOW_IMPLICIT_CONSTRUCTORS(JSWeakCell); |
| }; |
| |
| class JSWeakFactoryCleanupIterator : public JSObject { |
| public: |
| DECL_PRINTER(JSWeakFactoryCleanupIterator) |
| DECL_VERIFIER(JSWeakFactoryCleanupIterator) |
| DECL_CAST(JSWeakFactoryCleanupIterator) |
| |
| DECL_ACCESSORS(factory, JSWeakFactory) |
| |
| static const int kFactoryOffset = JSObject::kHeaderSize; |
| static const int kSize = kFactoryOffset + kPointerSize; |
| |
| private: |
| DISALLOW_IMPLICIT_CONSTRUCTORS(JSWeakFactoryCleanupIterator); |
| }; |
| |
| } // namespace internal |
| } // namespace v8 |
| |
| #include "src/objects/object-macros-undef.h" |
| |
| #endif // V8_OBJECTS_JS_WEAK_REFS_H_ |