1 //===-- tsan_interface.h ----------------------------------------*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file is a part of ThreadSanitizer (TSan), a race detector.
10 //
11 // Public interface header for TSan.
12 //===----------------------------------------------------------------------===//
13 #ifndef SANITIZER_TSAN_INTERFACE_H
14 #define SANITIZER_TSAN_INTERFACE_H
15 
16 #include <sanitizer/common_interface_defs.h>
17 
18 #ifdef __cplusplus
19 extern "C" {
20 #endif
21 
22 // __tsan_release establishes a happens-before relation with a preceding
23 // __tsan_acquire on the same address.
24 void __tsan_acquire(void *addr);
25 void __tsan_release(void *addr);
26 
27 // Annotations for custom mutexes.
28 // The annotations allow to get better reports (with sets of locked mutexes),
29 // detect more types of bugs (e.g. mutex misuses, races between lock/unlock and
30 // destruction and potential deadlocks) and improve precision and performance
31 // (by ignoring individual atomic operations in mutex code). However, the
32 // downside is that annotated mutex code itself is not checked for correctness.
33 
34 // Mutex creation flags are passed to __tsan_mutex_create annotation.
35 // If mutex has no constructor and __tsan_mutex_create is not called,
36 // the flags may be passed to __tsan_mutex_pre_lock/__tsan_mutex_post_lock
37 // annotations.
38 
39 // Mutex has static storage duration and no-op constructor and destructor.
40 // This effectively makes tsan ignore destroy annotation.
41 static const unsigned __tsan_mutex_linker_init      = 1 << 0;
42 // Mutex is write reentrant.
43 static const unsigned __tsan_mutex_write_reentrant  = 1 << 1;
44 // Mutex is read reentrant.
45 static const unsigned __tsan_mutex_read_reentrant   = 1 << 2;
46 // Mutex does not have static storage duration, and must not be used after
47 // its destructor runs.  The opposite of __tsan_mutex_linker_init.
48 // If this flag is passed to __tsan_mutex_destroy, then the destruction
49 // is ignored unless this flag was previously set on the mutex.
50 static const unsigned __tsan_mutex_not_static       = 1 << 8;
51 
52 // Mutex operation flags:
53 
54 // Denotes read lock operation.
55 static const unsigned __tsan_mutex_read_lock        = 1 << 3;
56 // Denotes try lock operation.
57 static const unsigned __tsan_mutex_try_lock         = 1 << 4;
58 // Denotes that a try lock operation has failed to acquire the mutex.
59 static const unsigned __tsan_mutex_try_lock_failed  = 1 << 5;
60 // Denotes that the lock operation acquires multiple recursion levels.
61 // Number of levels is passed in recursion parameter.
62 // This is useful for annotation of e.g. Java builtin monitors,
63 // for which wait operation releases all recursive acquisitions of the mutex.
64 static const unsigned __tsan_mutex_recursive_lock   = 1 << 6;
65 // Denotes that the unlock operation releases all recursion levels.
66 // Number of released levels is returned and later must be passed to
67 // the corresponding __tsan_mutex_post_lock annotation.
68 static const unsigned __tsan_mutex_recursive_unlock = 1 << 7;
69 
70 // Annotate creation of a mutex.
71 // Supported flags: mutex creation flags.
72 void __tsan_mutex_create(void *addr, unsigned flags);
73 
74 // Annotate destruction of a mutex.
75 // Supported flags:
76 //   - __tsan_mutex_linker_init
77 //   - __tsan_mutex_not_static
78 void __tsan_mutex_destroy(void *addr, unsigned flags);
79 
80 // Annotate start of lock operation.
81 // Supported flags:
82 //   - __tsan_mutex_read_lock
83 //   - __tsan_mutex_try_lock
84 //   - all mutex creation flags
85 void __tsan_mutex_pre_lock(void *addr, unsigned flags);
86 
87 // Annotate end of lock operation.
88 // Supported flags:
89 //   - __tsan_mutex_read_lock (must match __tsan_mutex_pre_lock)
90 //   - __tsan_mutex_try_lock (must match __tsan_mutex_pre_lock)
91 //   - __tsan_mutex_try_lock_failed
92 //   - __tsan_mutex_recursive_lock
93 //   - all mutex creation flags
94 void __tsan_mutex_post_lock(void *addr, unsigned flags, int recursion);
95 
96 // Annotate start of unlock operation.
97 // Supported flags:
98 //   - __tsan_mutex_read_lock
99 //   - __tsan_mutex_recursive_unlock
100 int __tsan_mutex_pre_unlock(void *addr, unsigned flags);
101 
102 // Annotate end of unlock operation.
103 // Supported flags:
104 //   - __tsan_mutex_read_lock (must match __tsan_mutex_pre_unlock)
105 void __tsan_mutex_post_unlock(void *addr, unsigned flags);
106 
107 // Annotate start/end of notify/signal/broadcast operation.
108 // Supported flags: none.
109 void __tsan_mutex_pre_signal(void *addr, unsigned flags);
110 void __tsan_mutex_post_signal(void *addr, unsigned flags);
111 
112 // Annotate start/end of a region of code where lock/unlock/signal operation
113 // diverts to do something else unrelated to the mutex. This can be used to
114 // annotate, for example, calls into cooperative scheduler or contention
115 // profiling code.
116 // These annotations must be called only from within
117 // __tsan_mutex_pre/post_lock, __tsan_mutex_pre/post_unlock,
118 // __tsan_mutex_pre/post_signal regions.
119 // Supported flags: none.
120 void __tsan_mutex_pre_divert(void *addr, unsigned flags);
121 void __tsan_mutex_post_divert(void *addr, unsigned flags);
122 
123 // External race detection API.
124 // Can be used by non-instrumented libraries to detect when their objects are
125 // being used in an unsafe manner.
126 //   - __tsan_external_read/__tsan_external_write annotates the logical reads
127 //       and writes of the object at the specified address. 'caller_pc' should
128 //       be the PC of the library user, which the library can obtain with e.g.
129 //       `__builtin_return_address(0)`.
130 //   - __tsan_external_register_tag registers a 'tag' with the specified name,
131 //       which is later used in read/write annotations to denote the object type
132 //   - __tsan_external_assign_tag can optionally mark a heap object with a tag
133 void *__tsan_external_register_tag(const char *object_type);
134 void __tsan_external_register_header(void *tag, const char *header);
135 void __tsan_external_assign_tag(void *addr, void *tag);
136 void __tsan_external_read(void *addr, void *caller_pc, void *tag);
137 void __tsan_external_write(void *addr, void *caller_pc, void *tag);
138 
139 // Fiber switching API.
140 //   - TSAN context for fiber can be created by __tsan_create_fiber
141 //     and freed by __tsan_destroy_fiber.
142 //   - TSAN context of current fiber or thread can be obtained
143 //     by calling __tsan_get_current_fiber.
144 //   - __tsan_switch_to_fiber should be called immediatly before switch
145 //     to fiber, such as call of swapcontext.
146 //   - Fiber name can be set by __tsan_set_fiber_name.
147 void *__tsan_get_current_fiber(void);
148 void *__tsan_create_fiber(unsigned flags);
149 void __tsan_destroy_fiber(void *fiber);
150 void __tsan_switch_to_fiber(void *fiber, unsigned flags);
151 void __tsan_set_fiber_name(void *fiber, const char *name);
152 
153 // Flags for __tsan_switch_to_fiber:
154 // Do not establish a happens-before relation between fibers
155 static const unsigned __tsan_switch_to_fiber_no_sync = 1 << 0;
156 
157 #ifdef __cplusplus
158 }  // extern "C"
159 #endif
160 
161 #endif  // SANITIZER_TSAN_INTERFACE_H
162