1 /**************************************************************************
2 *
3 * Copyright 1999-2006 Brian Paul
4 * Copyright 2008 VMware, Inc.
5 * All Rights Reserved.
6 *
7 * Permission is hereby granted, free of charge, to any person obtaining a
8 * copy of this software and associated documentation files (the "Software"),
9 * to deal in the Software without restriction, including without limitation
10 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
11 * and/or sell copies of the Software, and to permit persons to whom the
12 * Software is furnished to do so, subject to the following conditions:
13 *
14 * The above copyright notice and this permission notice shall be included
15 * in all copies or substantial portions of the Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
18 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
20 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
21 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
22 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
23 * OTHER DEALINGS IN THE SOFTWARE.
24 *
25 **************************************************************************/
26
27
28 /**
29 * @file
30 *
31 * Thread, mutex, condition variable, barrier, semaphore and
32 * thread-specific data functions.
33 */
34
35
36 #ifndef OS_THREAD_H_
37 #define OS_THREAD_H_
38
39
40 #include "pipe/p_compiler.h"
41 #include "util/u_debug.h" /* for assert */
42 #include "util/u_thread.h"
43
44
45 #define pipe_mutex_assert_locked(mutex) \
46 __pipe_mutex_assert_locked(&(mutex))
47
48 static inline void
__pipe_mutex_assert_locked(mtx_t * mutex)49 __pipe_mutex_assert_locked(mtx_t *mutex)
50 {
51 #ifdef DEBUG
52 /* NOTE: this would not work for recursive mutexes, but
53 * mtx_t doesn't support those
54 */
55 int ret = mtx_trylock(mutex);
56 assert(ret == thrd_busy);
57 if (ret == thrd_success)
58 mtx_unlock(mutex);
59 #else
60 (void)mutex;
61 #endif
62 }
63
64
65 /*
66 * Semaphores
67 */
68
69 typedef struct
70 {
71 mtx_t mutex;
72 cnd_t cond;
73 int counter;
74 } pipe_semaphore;
75
76
77 static inline void
pipe_semaphore_init(pipe_semaphore * sema,int init_val)78 pipe_semaphore_init(pipe_semaphore *sema, int init_val)
79 {
80 (void) mtx_init(&sema->mutex, mtx_plain);
81 cnd_init(&sema->cond);
82 sema->counter = init_val;
83 }
84
85 static inline void
pipe_semaphore_destroy(pipe_semaphore * sema)86 pipe_semaphore_destroy(pipe_semaphore *sema)
87 {
88 mtx_destroy(&sema->mutex);
89 cnd_destroy(&sema->cond);
90 }
91
92 /** Signal/increment semaphore counter */
93 static inline void
pipe_semaphore_signal(pipe_semaphore * sema)94 pipe_semaphore_signal(pipe_semaphore *sema)
95 {
96 mtx_lock(&sema->mutex);
97 sema->counter++;
98 cnd_signal(&sema->cond);
99 mtx_unlock(&sema->mutex);
100 }
101
102 /** Wait for semaphore counter to be greater than zero */
103 static inline void
pipe_semaphore_wait(pipe_semaphore * sema)104 pipe_semaphore_wait(pipe_semaphore *sema)
105 {
106 mtx_lock(&sema->mutex);
107 while (sema->counter <= 0) {
108 cnd_wait(&sema->cond, &sema->mutex);
109 }
110 sema->counter--;
111 mtx_unlock(&sema->mutex);
112 }
113
114 #endif /* OS_THREAD_H_ */
115