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/* Copyright (c) 2012, 2016, The Linux Foundation. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials provided
* with the distribution.
* * Neither the name of The Linux Foundation nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
* OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
* IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/
#ifndef __QCAMERA_SEMAPHORE_H__
#define __QCAMERA_SEMAPHORE_H__
// System dependencies
#include <pthread.h>
#include <errno.h>
#include "cam_cond.h"
#ifdef __cplusplus
extern "C" {
#endif
/* Implement semaphore with mutex and conditional variable.
* Reason being, POSIX semaphore on Android are not used or
* well tested.
*/
typedef struct {
int val;
pthread_mutex_t mutex;
pthread_cond_t cond;
} cam_semaphore_t;
static inline void cam_sem_init(cam_semaphore_t *s, int n)
{
pthread_mutex_init(&(s->mutex), NULL);
PTHREAD_COND_INIT(&(s->cond));
s->val = n;
}
static inline void cam_sem_post(cam_semaphore_t *s)
{
pthread_mutex_lock(&(s->mutex));
s->val++;
pthread_cond_signal(&(s->cond));
pthread_mutex_unlock(&(s->mutex));
}
static inline int cam_sem_wait(cam_semaphore_t *s)
{
int rc = 0;
pthread_mutex_lock(&(s->mutex));
while (s->val == 0)
rc = pthread_cond_wait(&(s->cond), &(s->mutex));
s->val--;
pthread_mutex_unlock(&(s->mutex));
return rc;
}
static inline int cam_sem_timedwait(cam_semaphore_t *s, const struct timespec *abs_timeout)
{
int rc = 0;
pthread_mutex_lock(&(s->mutex));
while (s->val == 0 && rc != ETIMEDOUT)
rc = pthread_cond_timedwait(&(s->cond), &(s->mutex), abs_timeout);
if (s->val > 0)
s->val--;
pthread_mutex_unlock(&(s->mutex));
/* sem_timedwait returns -1 for failure case, and failure code is in errno
*/
if (rc != 0) {
errno = rc;
rc = -1;
}
return rc;
}
static inline void cam_sem_destroy(cam_semaphore_t *s)
{
pthread_mutex_destroy(&(s->mutex));
pthread_cond_destroy(&(s->cond));
s->val = 0;
}
#ifdef __cplusplus
}
#endif
#endif /* __QCAMERA_SEMAPHORE_H__ */
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