1 /*
2  * Copyright (c) 2021-2024 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_FREE_OBJECT_H
17 #define ECMASCRIPT_FREE_OBJECT_H
18 
19 #include "ecmascript/js_hclass.h"
20 #include "ecmascript/mem/barriers.h"
21 #include "ecmascript/mem/tagged_object.h"
22 
23 #define INVALID_OBJECT ((FreeObject *) JSTaggedValue::NULL_POINTER)
24 
25 namespace panda::ecmascript {
26 class BaseHeap;
27 
28 class FreeObject : public TaggedObject {
29 public:
Cast(uintptr_t object)30     static FreeObject *Cast(uintptr_t object)
31     {
32         return reinterpret_cast<FreeObject *>(object);
33     }
34     static FreeObject *FillFreeObject(BaseHeap *heap, uintptr_t address, size_t size);
35 
IsEmpty() const36     inline bool IsEmpty() const
37     {
38         return Available() == 0;
39     }
40 
GetBegin() const41     inline uintptr_t GetBegin() const
42     {
43         return reinterpret_cast<uintptr_t>(this);
44     }
45 
GetEnd() const46     inline uintptr_t GetEnd() const
47     {
48         return reinterpret_cast<uintptr_t>(this) + Available();
49     }
50 
SetAvailable(uint32_t size)51     inline void SetAvailable(uint32_t size)
52     {
53         if (size >= SIZE) {
54             Barriers::SetPrimitive<JSTaggedType>(this, SIZE_OFFSET, JSTaggedValue(size).GetRawData());
55         }
56     }
57 
58     uint32_t Available() const;
59 
60     bool IsFreeObject() const;
61 
62     // Before operating any freeobject, need to mark unpoison when is_asan is true.
63     void AsanUnPoisonFreeObject() const;
64 
65     // After operating any freeobject, need to marked poison again when is_asan is true
66     void AsanPoisonFreeObject() const;
67 
68     static constexpr size_t NEXT_OFFSET = TaggedObjectSize();
69     ACCESSORS_FIXED_SIZE_FIELD(Next, FreeObject *, JSTaggedType, NEXT_OFFSET, SIZE_OFFSET)
70     // TaggedArray visitor may be error while concurrent marking
71     ACCESSORS(Size, SIZE_OFFSET, SIZE)
72 };
73 
74 static_assert((FreeObject::SIZE % static_cast<uint8_t>(MemAlignment::MEM_ALIGN_OBJECT)) == 0);
75 }  // namespace panda::ecmascript
76 
77 #endif  // ECMASCRIPT_MEM_FREE_OBJECT_H
78