2 This file is part of PulseAudio.
4 Copyright 2006 Lennart Poettering
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.
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.
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/>.
26 #include <semaphore.h>
28 #include <pulse/xmalloc.h>
29 #include <pulsecore/macro.h>
31 #include "semaphore.h"
37 pa_semaphore* pa_semaphore_new(unsigned value) {
40 s = pa_xnew(pa_semaphore, 1);
41 pa_assert_se(sem_init(&s->sem, 0, value) == 0);
45 void pa_semaphore_free(pa_semaphore *s) {
47 pa_assert_se(sem_destroy(&s->sem) == 0);
51 void pa_semaphore_post(pa_semaphore *s) {
53 pa_assert_se(sem_post(&s->sem) == 0);
56 void pa_semaphore_wait(pa_semaphore *s) {
61 ret = sem_wait(&s->sem);
62 } while (ret < 0 && errno == EINTR);
67 pa_semaphore* pa_static_semaphore_get(pa_static_semaphore *s, unsigned value) {
72 /* First, check if already initialized and short cut */
73 if ((m = pa_atomic_ptr_load(&s->ptr)))
76 /* OK, not initialized, so let's allocate, and fill in */
77 m = pa_semaphore_new(value);
78 if ((pa_atomic_ptr_cmpxchg(&s->ptr, NULL, m)))
83 /* Him, filling in failed, so someone else must have filled in
85 pa_assert_se(m = pa_atomic_ptr_load(&s->ptr));