1 /*
2  * Copyright (C) 2016 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #pragma once
18 
19 #include <mutex>
20 
21 #define THREAD_ANNOTATION_ATTRIBUTE__(x) __attribute__((x))
22 
23 #define CAPABILITY(x) \
24       THREAD_ANNOTATION_ATTRIBUTE__(capability(x))
25 
26 #define SCOPED_CAPABILITY \
27       THREAD_ANNOTATION_ATTRIBUTE__(scoped_lockable)
28 
29 #define SHARED_CAPABILITY(...) \
30       THREAD_ANNOTATION_ATTRIBUTE__(shared_capability(__VA_ARGS__))
31 
32 #define GUARDED_BY(x) \
33       THREAD_ANNOTATION_ATTRIBUTE__(guarded_by(x))
34 
35 #define PT_GUARDED_BY(x) \
36       THREAD_ANNOTATION_ATTRIBUTE__(pt_guarded_by(x))
37 
38 #define EXCLUSIVE_LOCKS_REQUIRED(...) \
39       THREAD_ANNOTATION_ATTRIBUTE__(exclusive_locks_required(__VA_ARGS__))
40 
41 #define SHARED_LOCKS_REQUIRED(...) \
42       THREAD_ANNOTATION_ATTRIBUTE__(shared_locks_required(__VA_ARGS__))
43 
44 #define ACQUIRED_BEFORE(...) \
45       THREAD_ANNOTATION_ATTRIBUTE__(acquired_before(__VA_ARGS__))
46 
47 #define ACQUIRED_AFTER(...) \
48       THREAD_ANNOTATION_ATTRIBUTE__(acquired_after(__VA_ARGS__))
49 
50 #define REQUIRES(...) \
51       THREAD_ANNOTATION_ATTRIBUTE__(requires_capability(__VA_ARGS__))
52 
53 #define REQUIRES_SHARED(...) \
54       THREAD_ANNOTATION_ATTRIBUTE__(requires_shared_capability(__VA_ARGS__))
55 
56 #define ACQUIRE(...) \
57       THREAD_ANNOTATION_ATTRIBUTE__(acquire_capability(__VA_ARGS__))
58 
59 #define ACQUIRE_SHARED(...) \
60       THREAD_ANNOTATION_ATTRIBUTE__(acquire_shared_capability(__VA_ARGS__))
61 
62 #define RELEASE(...) \
63       THREAD_ANNOTATION_ATTRIBUTE__(release_capability(__VA_ARGS__))
64 
65 #define RELEASE_SHARED(...) \
66       THREAD_ANNOTATION_ATTRIBUTE__(release_shared_capability(__VA_ARGS__))
67 
68 #define TRY_ACQUIRE(...) \
69       THREAD_ANNOTATION_ATTRIBUTE__(try_acquire_capability(__VA_ARGS__))
70 
71 #define TRY_ACQUIRE_SHARED(...) \
72       THREAD_ANNOTATION_ATTRIBUTE__(try_acquire_shared_capability(__VA_ARGS__))
73 
74 #define EXCLUDES(...) \
75       THREAD_ANNOTATION_ATTRIBUTE__(locks_excluded(__VA_ARGS__))
76 
77 #define ASSERT_CAPABILITY(x) \
78       THREAD_ANNOTATION_ATTRIBUTE__(assert_capability(x))
79 
80 #define ASSERT_SHARED_CAPABILITY(x) \
81       THREAD_ANNOTATION_ATTRIBUTE__(assert_shared_capability(x))
82 
83 #define RETURN_CAPABILITY(x) \
84       THREAD_ANNOTATION_ATTRIBUTE__(lock_returned(x))
85 
86 #define EXCLUSIVE_LOCK_FUNCTION(...) \
87       THREAD_ANNOTATION_ATTRIBUTE__(exclusive_lock_function(__VA_ARGS__))
88 
89 #define EXCLUSIVE_TRYLOCK_FUNCTION(...) \
90       THREAD_ANNOTATION_ATTRIBUTE__(exclusive_trylock_function(__VA_ARGS__))
91 
92 #define SHARED_LOCK_FUNCTION(...) \
93       THREAD_ANNOTATION_ATTRIBUTE__(shared_lock_function(__VA_ARGS__))
94 
95 #define SHARED_TRYLOCK_FUNCTION(...) \
96       THREAD_ANNOTATION_ATTRIBUTE__(shared_trylock_function(__VA_ARGS__))
97 
98 #define UNLOCK_FUNCTION(...) \
99       THREAD_ANNOTATION_ATTRIBUTE__(unlock_function(__VA_ARGS__))
100 
101 #define SCOPED_LOCKABLE \
102       THREAD_ANNOTATION_ATTRIBUTE__(scoped_lockable)
103 
104 #define LOCK_RETURNED(x) \
105       THREAD_ANNOTATION_ATTRIBUTE__(lock_returned(x))
106 
107 #define NO_THREAD_SAFETY_ANALYSIS \
108       THREAD_ANNOTATION_ATTRIBUTE__(no_thread_safety_analysis)
109 
110 namespace android {
111 namespace base {
112 
113 // A class to help thread safety analysis deal with std::unique_lock and condition_variable.
114 //
115 // Clang's thread safety analysis currently doesn't perform alias analysis, so movable types
116 // like std::unique_lock can't be marked with thread safety annotations. This helper allows
117 // for manual assertion of lock state in a scope.
118 //
119 // For example:
120 //
121 //   std::mutex mutex;
122 //   std::condition_variable cv;
123 //   std::vector<int> vec GUARDED_BY(mutex);
124 //
125 //   int pop() {
126 //     std::unique_lock lock(mutex);
127 //     ScopedLockAssertion lock_assertion(mutex);
128 //     cv.wait(lock, []() {
129 //       ScopedLockAssertion lock_assertion(mutex);
130 //       return !vec.empty();
131 //     });
132 //
133 //     int result = vec.back();
134 //     vec.pop_back();
135 //     return result;
136 //   }
137 class SCOPED_CAPABILITY ScopedLockAssertion {
138  public:
ScopedLockAssertion(std::mutex & mutex)139   ScopedLockAssertion(std::mutex& mutex) ACQUIRE(mutex) {}
RELEASE()140   ~ScopedLockAssertion() RELEASE() {}
141 };
142 
143 }  // namespace base
144 }  // namespace android
145