|
236
|
1 //===----------------------------------------------------------------------===//
|
|
150
|
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 // Abstract interface to shared reader/writer log, hiding platform and
|
|
|
9 // configuration differences.
|
|
|
10 //
|
|
|
11 //===----------------------------------------------------------------------===//
|
|
|
12
|
|
|
13 #ifndef __RWMUTEX_HPP__
|
|
|
14 #define __RWMUTEX_HPP__
|
|
|
15
|
|
|
16 #if defined(_WIN32)
|
|
|
17 #include <windows.h>
|
|
|
18 #elif !defined(_LIBUNWIND_HAS_NO_THREADS)
|
|
|
19 #include <pthread.h>
|
|
|
20 #if defined(__ELF__) && defined(_LIBUNWIND_LINK_PTHREAD_LIB)
|
|
|
21 #pragma comment(lib, "pthread")
|
|
|
22 #endif
|
|
|
23 #endif
|
|
|
24
|
|
|
25 namespace libunwind {
|
|
|
26
|
|
|
27 #if defined(_LIBUNWIND_HAS_NO_THREADS)
|
|
|
28
|
|
|
29 class _LIBUNWIND_HIDDEN RWMutex {
|
|
|
30 public:
|
|
|
31 bool lock_shared() { return true; }
|
|
|
32 bool unlock_shared() { return true; }
|
|
|
33 bool lock() { return true; }
|
|
|
34 bool unlock() { return true; }
|
|
|
35 };
|
|
|
36
|
|
|
37 #elif defined(_WIN32)
|
|
|
38
|
|
|
39 class _LIBUNWIND_HIDDEN RWMutex {
|
|
|
40 public:
|
|
|
41 bool lock_shared() {
|
|
|
42 AcquireSRWLockShared(&_lock);
|
|
|
43 return true;
|
|
|
44 }
|
|
|
45 bool unlock_shared() {
|
|
|
46 ReleaseSRWLockShared(&_lock);
|
|
|
47 return true;
|
|
|
48 }
|
|
|
49 bool lock() {
|
|
|
50 AcquireSRWLockExclusive(&_lock);
|
|
|
51 return true;
|
|
|
52 }
|
|
|
53 bool unlock() {
|
|
|
54 ReleaseSRWLockExclusive(&_lock);
|
|
|
55 return true;
|
|
|
56 }
|
|
|
57
|
|
|
58 private:
|
|
|
59 SRWLOCK _lock = SRWLOCK_INIT;
|
|
|
60 };
|
|
|
61
|
|
|
62 #elif !defined(LIBUNWIND_USE_WEAK_PTHREAD)
|
|
|
63
|
|
|
64 class _LIBUNWIND_HIDDEN RWMutex {
|
|
|
65 public:
|
|
|
66 bool lock_shared() { return pthread_rwlock_rdlock(&_lock) == 0; }
|
|
|
67 bool unlock_shared() { return pthread_rwlock_unlock(&_lock) == 0; }
|
|
|
68 bool lock() { return pthread_rwlock_wrlock(&_lock) == 0; }
|
|
|
69 bool unlock() { return pthread_rwlock_unlock(&_lock) == 0; }
|
|
|
70
|
|
|
71 private:
|
|
|
72 pthread_rwlock_t _lock = PTHREAD_RWLOCK_INITIALIZER;
|
|
|
73 };
|
|
|
74
|
|
|
75 #else
|
|
|
76
|
|
|
77 extern "C" int __attribute__((weak))
|
|
|
78 pthread_create(pthread_t *thread, const pthread_attr_t *attr,
|
|
|
79 void *(*start_routine)(void *), void *arg);
|
|
|
80 extern "C" int __attribute__((weak))
|
|
|
81 pthread_rwlock_rdlock(pthread_rwlock_t *lock);
|
|
|
82 extern "C" int __attribute__((weak))
|
|
|
83 pthread_rwlock_wrlock(pthread_rwlock_t *lock);
|
|
|
84 extern "C" int __attribute__((weak))
|
|
|
85 pthread_rwlock_unlock(pthread_rwlock_t *lock);
|
|
|
86
|
|
|
87 // Calls to the locking functions are gated on pthread_create, and not the
|
|
|
88 // functions themselves, because the data structure should only be locked if
|
|
|
89 // another thread has been created. This is what similar libraries do.
|
|
|
90
|
|
|
91 class _LIBUNWIND_HIDDEN RWMutex {
|
|
|
92 public:
|
|
|
93 bool lock_shared() {
|
|
|
94 return !pthread_create || (pthread_rwlock_rdlock(&_lock) == 0);
|
|
|
95 }
|
|
|
96 bool unlock_shared() {
|
|
|
97 return !pthread_create || (pthread_rwlock_unlock(&_lock) == 0);
|
|
|
98 }
|
|
|
99 bool lock() {
|
|
|
100 return !pthread_create || (pthread_rwlock_wrlock(&_lock) == 0);
|
|
|
101 }
|
|
|
102 bool unlock() {
|
|
|
103 return !pthread_create || (pthread_rwlock_unlock(&_lock) == 0);
|
|
|
104 }
|
|
|
105
|
|
|
106 private:
|
|
|
107 pthread_rwlock_t _lock = PTHREAD_RWLOCK_INITIALIZER;
|
|
|
108 };
|
|
|
109
|
|
|
110 #endif
|
|
|
111
|
|
|
112 } // namespace libunwind
|
|
|
113
|
|
|
114 #endif // __RWMUTEX_HPP__
|
