1 /***
2 This file is part of PulseAudio.
3
4 Copyright 2006 Lennart Poettering
5
6 PulseAudio is free software; you can redistribute it and/or modify
7 it under the terms of the GNU Lesser General Public License as published
8 by the Free Software Foundation; either version 2.1 of the License,
9 or (at your option) any later version.
10
11 PulseAudio is distributed in the hope that it will be useful, but
12 WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 General Public License for more details.
15
16 You should have received a copy of the GNU Lesser General Public License
17 along with PulseAudio; if not, see <http://www.gnu.org/licenses/>.
18 ***/
19
20 #ifdef HAVE_CONFIG_H
21 #include <config.h>
22 #endif
23
24 #include <pthread.h>
25 #include <errno.h>
26
27 #include <pulse/xmalloc.h>
28 #include <pulsecore/macro.h>
29
30 #include "mutex.h"
31
32 struct pa_mutex {
33 pthread_mutex_t mutex;
34 };
35
36 struct pa_cond {
37 pthread_cond_t cond;
38 };
39
pa_mutex_new(bool recursive,bool inherit_priority)40 pa_mutex* pa_mutex_new(bool recursive, bool inherit_priority) {
41 pa_mutex *m;
42 pthread_mutexattr_t attr;
43 #ifdef HAVE_PTHREAD_PRIO_INHERIT
44 int r;
45 #endif
46
47 pa_assert_se(pthread_mutexattr_init(&attr) == 0);
48
49 if (recursive)
50 pa_assert_se(pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE) == 0);
51
52 #ifdef HAVE_PTHREAD_PRIO_INHERIT
53 if (inherit_priority) {
54 r = pthread_mutexattr_setprotocol(&attr, PTHREAD_PRIO_INHERIT);
55 pa_assert(r == 0 || r == ENOTSUP);
56 }
57 #endif
58
59 m = pa_xnew(pa_mutex, 1);
60
61 #ifndef HAVE_PTHREAD_PRIO_INHERIT
62 pa_assert_se(pthread_mutex_init(&m->mutex, &attr) == 0);
63
64 #else
65 if ((r = pthread_mutex_init(&m->mutex, &attr))) {
66
67 /* If this failed, then this was probably due to non-available
68 * priority inheritance. In which case we fall back to normal
69 * mutexes. */
70 pa_assert(r == ENOTSUP && inherit_priority);
71
72 pa_assert_se(pthread_mutexattr_setprotocol(&attr, PTHREAD_PRIO_NONE) == 0);
73 pa_assert_se(pthread_mutex_init(&m->mutex, &attr) == 0);
74 }
75 #endif
76
77 return m;
78 }
79
pa_mutex_free(pa_mutex * m)80 void pa_mutex_free(pa_mutex *m) {
81 pa_assert(m);
82
83 pa_assert_se(pthread_mutex_destroy(&m->mutex) == 0);
84 pa_xfree(m);
85 }
86
pa_mutex_lock(pa_mutex * m)87 void pa_mutex_lock(pa_mutex *m) {
88 pa_assert(m);
89
90 pa_assert_se(pthread_mutex_lock(&m->mutex) == 0);
91 }
92
pa_mutex_try_lock(pa_mutex * m)93 bool pa_mutex_try_lock(pa_mutex *m) {
94 int r;
95 pa_assert(m);
96
97 if ((r = pthread_mutex_trylock(&m->mutex)) != 0) {
98 pa_assert(r == EBUSY);
99 return false;
100 }
101
102 return true;
103 }
104
pa_mutex_unlock(pa_mutex * m)105 void pa_mutex_unlock(pa_mutex *m) {
106 pa_assert(m);
107
108 pa_assert_se(pthread_mutex_unlock(&m->mutex) == 0);
109 }
110
pa_cond_new(void)111 pa_cond *pa_cond_new(void) {
112 pa_cond *c;
113
114 c = pa_xnew(pa_cond, 1);
115 pa_assert_se(pthread_cond_init(&c->cond, NULL) == 0);
116 return c;
117 }
118
pa_cond_free(pa_cond * c)119 void pa_cond_free(pa_cond *c) {
120 pa_assert(c);
121
122 pa_assert_se(pthread_cond_destroy(&c->cond) == 0);
123 pa_xfree(c);
124 }
125
pa_cond_signal(pa_cond * c,int broadcast)126 void pa_cond_signal(pa_cond *c, int broadcast) {
127 pa_assert(c);
128
129 if (broadcast)
130 pa_assert_se(pthread_cond_broadcast(&c->cond) == 0);
131 else
132 pa_assert_se(pthread_cond_signal(&c->cond) == 0);
133 }
134
pa_cond_wait(pa_cond * c,pa_mutex * m)135 int pa_cond_wait(pa_cond *c, pa_mutex *m) {
136 pa_assert(c);
137 pa_assert(m);
138
139 return pthread_cond_wait(&c->cond, &m->mutex);
140 }
141
pa_static_mutex_get(pa_static_mutex * s,bool recursive,bool inherit_priority)142 pa_mutex* pa_static_mutex_get(pa_static_mutex *s, bool recursive, bool inherit_priority) {
143 pa_mutex *m;
144
145 pa_assert(s);
146
147 /* First, check if already initialized and short cut */
148 if ((m = pa_atomic_ptr_load(&s->ptr)))
149 return m;
150
151 /* OK, not initialized, so let's allocate, and fill in */
152 m = pa_mutex_new(recursive, inherit_priority);
153 if ((pa_atomic_ptr_cmpxchg(&s->ptr, NULL, m)))
154 return m;
155
156 pa_mutex_free(m);
157
158 /* Him, filling in failed, so someone else must have filled in
159 * already */
160 pa_assert_se(m = pa_atomic_ptr_load(&s->ptr));
161 return m;
162 }
163