// 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" #include "torque-generated/bit-fields-tq.h" // Has to be the last include (doesn't have include guards): #include "src/objects/object-macros.h" namespace v8 { namespace internal { class NativeContext; class WeakCell; // FinalizationRegistry object from the JS Weak Refs spec proposal: // https://github.com/tc39/proposal-weakrefs class JSFinalizationRegistry : public JSObject { public: DECL_PRINTER(JSFinalizationRegistry) EXPORT_DECL_VERIFIER(JSFinalizationRegistry) DECL_CAST(JSFinalizationRegistry) DECL_ACCESSORS(native_context, NativeContext) DECL_ACCESSORS(cleanup, Object) DECL_ACCESSORS(active_cells, HeapObject) DECL_ACCESSORS(cleared_cells, HeapObject) DECL_ACCESSORS(key_map, Object) DECL_ACCESSORS(next_dirty, Object) DECL_INT_ACCESSORS(flags) DECL_BOOLEAN_ACCESSORS(scheduled_for_cleanup) class BodyDescriptor; inline static void Register( Handle<JSFinalizationRegistry> finalization_registry, Handle<JSReceiver> target, Handle<Object> holdings, Handle<Object> key, Isolate* isolate); inline static bool Unregister( Handle<JSFinalizationRegistry> finalization_registry, Handle<JSReceiver> unregister_token, Isolate* isolate); // RemoveUnregisterToken is called from both Unregister and during GC. Since // it modifies slots in key_map and WeakCells and the normal write barrier is // disabled during GC, we need to tell the GC about the modified slots via the // gc_notify_updated_slot function. template <typename MatchCallback, typename GCNotifyUpdatedSlotCallback> inline bool RemoveUnregisterToken( JSReceiver unregister_token, Isolate* isolate, MatchCallback match_callback, GCNotifyUpdatedSlotCallback gc_notify_updated_slot); // Returns true if the cleared_cells list is non-empty. inline bool NeedsCleanup() const; // Remove the already-popped weak_cell from its unregister token linked list, // as well as removing the entry from the key map if it is the only WeakCell // with its unregister token. This method cannot GC and does not shrink the // key map. Asserts that weak_cell has a non-undefined unregister token. // // It takes raw Addresses because it is called from CSA and Torque. V8_EXPORT_PRIVATE static void RemoveCellFromUnregisterTokenMap( Isolate* isolate, Address raw_finalization_registry, Address raw_weak_cell); // Layout description. DEFINE_FIELD_OFFSET_CONSTANTS( JSObject::kHeaderSize, TORQUE_GENERATED_JS_FINALIZATION_REGISTRY_FIELDS) // Bitfields in flags. DEFINE_TORQUE_GENERATED_FINALIZATION_REGISTRY_FLAGS() OBJECT_CONSTRUCTORS(JSFinalizationRegistry, JSObject); }; // Internal object for storing weak references in JSFinalizationRegistry. class WeakCell : public TorqueGeneratedWeakCell<WeakCell, HeapObject> { public: DECL_PRINTER(WeakCell) EXPORT_DECL_VERIFIER(WeakCell) class BodyDescriptor; // Provide relaxed load access to target field. inline HeapObject relaxed_target() const; // Nullify is called during GC and it modifies the pointers in WeakCell and // JSFinalizationRegistry. 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. template <typename GCNotifyUpdatedSlotCallback> inline void Nullify(Isolate* isolate, GCNotifyUpdatedSlotCallback gc_notify_updated_slot); inline void RemoveFromFinalizationRegistryCells(Isolate* isolate); TQ_OBJECT_CONSTRUCTORS(WeakCell) }; class JSWeakRef : public TorqueGeneratedJSWeakRef<JSWeakRef, JSObject> { public: DECL_PRINTER(JSWeakRef) EXPORT_DECL_VERIFIER(JSWeakRef) class BodyDescriptor; TQ_OBJECT_CONSTRUCTORS(JSWeakRef) }; } // namespace internal } // namespace v8 #include "src/objects/object-macros-undef.h" #endif // V8_OBJECTS_JS_WEAK_REFS_H_