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
48static inline void
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
69typedef struct
70{
71   mtx_t mutex;
72   cnd_t cond;
73   int counter;
74} pipe_semaphore;
75
76
77static inline void
78pipe_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
85static inline void
86pipe_semaphore_destroy(pipe_semaphore *sema)
87{
88   mtx_destroy(&sema->mutex);
89   cnd_destroy(&sema->cond);
90}
91
92/** Signal/increment semaphore counter */
93static inline void
94pipe_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 */
103static inline void
104pipe_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