1 /* 2 * Copyright (c) 2022 Huawei Device Co., Ltd. 3 * Licensed under the Apache License, Version 2.0 (the "License"); 4 * you may not use this file except in compliance with the License. 5 * You may obtain a copy of the License at 6 * 7 * http://www.apache.org/licenses/LICENSE-2.0 8 * 9 * Unless required by applicable law or agreed to in writing, software 10 * distributed under the License is distributed on an "AS IS" BASIS, 11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 * See the License for the specific language governing permissions and 13 * limitations under the License. 14 */ 15 16 #ifndef ECMASCRIPT_JS_WEAK_REF_H 17 #define ECMASCRIPT_JS_WEAK_REF_H 18 19 #include "ecmascript/js_object.h" 20 #include "ecmascript/js_tagged_value-inl.h" 21 22 namespace panda::ecmascript { 23 class JSWeakRef : public JSObject { 24 public: Cast(TaggedObject * object)25 static JSWeakRef *Cast(TaggedObject *object) 26 { 27 ASSERT(JSTaggedValue(object).IsJSWeakRef()); 28 return static_cast<JSWeakRef *>(object); 29 } 30 31 // 26.1.4.1 WeakRefDeref ( weakRef ) WeakRefDeref(JSThread * thread,const JSHandle<JSWeakRef> & weakRef)32 static JSTaggedValue WeakRefDeref(JSThread *thread, const JSHandle<JSWeakRef> &weakRef) 33 { 34 // 1. Let target be weakRef.[[WeakRefTarget]]. 35 // 2. If target is not empty, then 36 // a. Perform ! AddToKeptObjects(target). 37 // b. Return target. 38 // 3. Return undefined. 39 JSHandle<JSTaggedValue> target(thread, weakRef->GetFromWeak()); 40 if (!target->IsUndefined()) { 41 thread->GetEcmaVM()->GetHeap()->AddToKeptObjects(target); 42 } 43 return target.GetTaggedValue(); 44 } 45 SetToWeak(JSThread * thread,JSTaggedValue value)46 void SetToWeak(JSThread *thread, JSTaggedValue value) 47 { 48 JSTaggedValue weakObj = JSTaggedValue(value.CreateAndGetWeakRef()); 49 ASSERT(weakObj.IsWeak()); 50 SetWeakObject(thread, weakObj); 51 } 52 GetFromWeak()53 JSTaggedValue GetFromWeak() const 54 { 55 JSTaggedValue weakObj = GetWeakObject(); 56 if (!weakObj.IsUndefined()) { 57 return JSTaggedValue(weakObj.GetWeakReferent()); 58 } 59 return weakObj; 60 } 61 static constexpr size_t WEAK_OBJECT_OFFSET = JSObject::SIZE; 62 ACCESSORS(WeakObject, WEAK_OBJECT_OFFSET, SIZE) 63 64 DECL_VISIT_OBJECT_FOR_JS_OBJECT(JSObject, WEAK_OBJECT_OFFSET, SIZE) 65 DECL_DUMP() 66 }; 67 } // namespace 68 #endif // ECMASCRIPT_JS_WEAK_REF_H