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This file is part of PulseAudio.
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Copyright 2006 Lennart Poettering
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PulseAudio is free software; you can redistribute it and/or modify
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it under the terms of the GNU Lesser General Public License as published
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by the Free Software Foundation; either version 2.1 of the License,
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or (at your option) any later version.
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PulseAudio is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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General Public License for more details.
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You should have received a copy of the GNU Lesser General Public License
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along with PulseAudio; if not, see <http://www.gnu.org/licenses/>.
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#include <semaphore.h>
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#include <pulse/xmalloc.h>
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#include <pulsecore/macro.h>
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#include "semaphore.h"
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pa_semaphore* pa_semaphore_new(unsigned value) {
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s = pa_xnew(pa_semaphore, 1);
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pa_assert_se(sem_init(&s->sem, 0, value) == 0);
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void pa_semaphore_free(pa_semaphore *s) {
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pa_assert_se(sem_destroy(&s->sem) == 0);
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void pa_semaphore_post(pa_semaphore *s) {
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pa_assert_se(sem_post(&s->sem) == 0);
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void pa_semaphore_wait(pa_semaphore *s) {
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ret = sem_wait(&s->sem);
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} while (ret < 0 && errno == EINTR);
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pa_semaphore* pa_static_semaphore_get(pa_static_semaphore *s, unsigned value) {
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/* First, check if already initialized and short cut */
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if ((m = pa_atomic_ptr_load(&s->ptr)))
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/* OK, not initialized, so let's allocate, and fill in */
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m = pa_semaphore_new(value);
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if ((pa_atomic_ptr_cmpxchg(&s->ptr, NULL, m)))
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/* Him, filling in failed, so someone else must have filled in
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pa_assert_se(m = pa_atomic_ptr_load(&s->ptr));