| /* 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> |
| |
| #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), NULL); |
| 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 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__ */ |