obs-studio/libobs/util/threading.h

131 lines
3.1 KiB
C

/*
* Copyright (c) 2013 Hugh Bailey <obs.jim@gmail.com>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#pragma once
/*
* Allows posix thread usage on windows as well as other operating systems.
* Use this header if you want to make your code more platform independent.
*
* Also provides a custom platform-independent "event" handler via
* pthread conditional waits.
*/
#include "c99defs.h"
#ifdef _MSC_VER
#include "../../deps/w32-pthreads/pthread.h"
#include "../../deps/w32-pthreads/semaphore.h"
#else
#include <errno.h>
#include <pthread.h>
#include <semaphore.h>
#endif
#ifdef __cplusplus
extern "C" {
#endif
/* this may seem strange, but you can't use it unless it's an initializer */
static inline void pthread_mutex_init_value(pthread_mutex_t *mutex)
{
pthread_mutex_t init_val = PTHREAD_MUTEX_INITIALIZER;
*mutex = init_val;
}
struct event_data {
pthread_mutex_t mutex;
pthread_cond_t cond;
bool signalled;
bool manual;
};
typedef struct event_data event_t;
static inline int event_init(event_t *event, bool manual)
{
int code = 0;
if ((code = pthread_mutex_init(&event->mutex, NULL)) < 0)
return code;
if ((code = pthread_cond_init(&event->cond, NULL)) < 0)
pthread_mutex_destroy(&event->mutex);
event->manual = manual;
event->signalled = false;
return code;
}
static inline void event_destroy(event_t *event)
{
if (event) {
pthread_mutex_destroy(&event->mutex);
pthread_cond_destroy(&event->cond);
}
}
static inline int event_wait(event_t *event)
{
int code = 0;
pthread_mutex_lock(&event->mutex);
if ((code = pthread_cond_wait(&event->cond, &event->mutex)) == 0) {
if (!event->manual)
event->signalled = false;
pthread_mutex_unlock(&event->mutex);
}
return code;
}
static inline int event_try(event_t *event)
{
pthread_mutex_lock(&event->mutex);
if (event->signalled) {
if (!event->manual)
event->signalled = false;
pthread_mutex_unlock(&event->mutex);
return 0;
}
pthread_mutex_unlock(&event->mutex);
return EAGAIN;
}
static inline int event_signal(event_t *event)
{
int code = 0;
pthread_mutex_lock(&event->mutex);
code = pthread_cond_signal(&event->cond);
event->signalled = true;
pthread_mutex_unlock(&event->mutex);
return code;
}
static inline void event_reset(event_t *event)
{
pthread_mutex_lock(&event->mutex);
event->signalled = false;
pthread_mutex_unlock(&event->mutex);
}
#ifdef __cplusplus
}
#endif