1/*
2 * Copyright (c) 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 THREAD_SAFETY_ANNOTATIONS_H
17#define THREAD_SAFETY_ANNOTATIONS_H
18
19// https://clang.llvm.org/docs/ThreadSafetyAnalysis.html
20// Enable thread safety attributes only with clang.
21// The attributes can be safely erased when compiling with other compilers.
22#if defined(__clang__) && (!defined(SWIG))
23#define THREAD_ANNOTATION_ATTRIBUTE__(x)   __attribute__((x))
24#else
25#define THREAD_ANNOTATION_ATTRIBUTE__(x)   // no-op
26#endif
27
28#define CAPABILITY(x) \
29  THREAD_ANNOTATION_ATTRIBUTE__(capability(x))
30
31#define SCOPED_CAPABILITY \
32  THREAD_ANNOTATION_ATTRIBUTE__(scoped_lockable)
33
34#define GUARDED_BY(x) \
35  THREAD_ANNOTATION_ATTRIBUTE__(guarded_by(x))
36
37#define PT_GUARDED_BY(x) \
38  THREAD_ANNOTATION_ATTRIBUTE__(pt_guarded_by(x))
39
40#define ACQUIRED_BEFORE(...) \
41  THREAD_ANNOTATION_ATTRIBUTE__(acquired_before(__VA_ARGS__))
42
43#define ACQUIRED_AFTER(...) \
44  THREAD_ANNOTATION_ATTRIBUTE__(acquired_after(__VA_ARGS__))
45
46#define REQUIRES(...) \
47  THREAD_ANNOTATION_ATTRIBUTE__(requires_capability(__VA_ARGS__))
48
49#define REQUIRES_SHARED(...) \
50  THREAD_ANNOTATION_ATTRIBUTE__(requires_shared_capability(__VA_ARGS__))
51
52#define ACQUIRE(...) \
53  THREAD_ANNOTATION_ATTRIBUTE__(acquire_capability(__VA_ARGS__))
54
55#define ACQUIRE_SHARED(...) \
56  THREAD_ANNOTATION_ATTRIBUTE__(acquire_shared_capability(__VA_ARGS__))
57
58#define RELEASE(...) \
59  THREAD_ANNOTATION_ATTRIBUTE__(release_capability(__VA_ARGS__))
60
61#define RELEASE_SHARED(...) \
62  THREAD_ANNOTATION_ATTRIBUTE__(release_shared_capability(__VA_ARGS__))
63
64#define RELEASE_GENERIC(...) \
65  THREAD_ANNOTATION_ATTRIBUTE__(release_generic_capability(__VA_ARGS__))
66
67#define TRY_ACQUIRE(...) \
68  THREAD_ANNOTATION_ATTRIBUTE__(try_acquire_capability(__VA_ARGS__))
69
70#define TRY_ACQUIRE_SHARED(...) \
71  THREAD_ANNOTATION_ATTRIBUTE__(try_acquire_shared_capability(__VA_ARGS__))
72
73#define EXCLUDES(...) \
74  THREAD_ANNOTATION_ATTRIBUTE__(locks_excluded(__VA_ARGS__))
75
76#define ASSERT_CAPABILITY(x) \
77  THREAD_ANNOTATION_ATTRIBUTE__(assert_capability(x))
78
79#define ASSERT_SHARED_CAPABILITY(x) \
80  THREAD_ANNOTATION_ATTRIBUTE__(assert_shared_capability(x))
81
82#define RETURN_CAPABILITY(x) \
83  THREAD_ANNOTATION_ATTRIBUTE__(lock_returned(x))
84
85#define NO_THREAD_SAFETY_ANALYSIS \
86  THREAD_ANNOTATION_ATTRIBUTE__(no_thread_safety_analysis)
87
88namespace OHOS::Rosen {
89class CAPABILITY("mutex") SingleThreadGuard {};
90
91// ONLY used for those accessed ONLY on scene session manager thread.
92// If other looper threads(NOT ffrt or ipc), define a new one.
93constexpr SingleThreadGuard SCENE_GUARD;
94
95template <typename Guard>
96struct SCOPED_CAPABILITY ScopedGuard final {
97    explicit ScopedGuard(const Guard& guard) ACQUIRE(guard) {}
98    ~ScopedGuard() RELEASE() {}
99
100    ScopedGuard(const ScopedGuard&) = delete;
101    ScopedGuard& operator=(const ScopedGuard&) = delete;
102};
103
104} // namespace OHOS::Rosen
105
106// Use this for lambdas. THREAD_SAFETY_GUARD is preferred.
107#define LOCK_GUARD(guard)  \
108    ACQUIRE(guard) RELEASE(guard)
109
110// Use this for expressions. THREAD_SAFETY_GUARD is preferred.
111#define LOCK_GUARD_TWO(guard, expr)  \
112    (OHOS::Rosen::ScopedGuard(guard), expr)
113
114// Use this when LOCK_GUARD_TWO/THREAD_SAFETY_GUARD works failed.
115#define LOCK_GUARD_EXPR(guard, expr)           \
116    [&] {                                      \
117        OHOS::Rosen::ScopedGuard lock(guard);  \
118        return (expr);                         \
119    }()
120
121// Do not use this.
122#define CREATE_THREAD_SAFETY_GUARD(opt1, opt2, guard, ...) guard
123
124// Use THREAD_SAFETY_GUARD for common cases, including LOCK_GUARD and LOCK_GUARD_TWO.
125#define THREAD_SAFETY_GUARD(...) \
126    CREATE_THREAD_SAFETY_GUARD(__VA_ARGS__, LOCK_GUARD_TWO, LOCK_GUARD,)(__VA_ARGS__)
127
128#endif // THREAD_SAFETY_ANNOTATIONS_H
129