tsemaphore.c

Go to the documentation of this file.

#include <pthread.h>
#include <sys/time.h>
#include <errno.h>
#include "tsemaphore.h"
#include "omx_comp_debug_levels.h"

OSCL_EXPORT_REF int tsem_init(tsem_t* tsem, unsigned int val) {
    int i;
    i = pthread_cond_init(&tsem->condition, NULL);
    if (i!=0) {
        return -1;
    }
    i = pthread_mutex_init(&tsem->mutex, NULL);
    if (i!=0) {
        return -1;
    }
    tsem->semval = val;
    return 0;
}

OSCL_EXPORT_REF void tsem_deinit(tsem_t* tsem) {
  pthread_cond_destroy(&tsem->condition);
  pthread_mutex_destroy(&tsem->mutex);
}

OSCL_EXPORT_REF int tsem_timed_down(tsem_t* tsem, unsigned int milliSecondsDelay) {
    int err = 0;
    struct timespec final_time;
    struct timeval currentTime;
    long int microdelay;

    gettimeofday(&currentTime, NULL);
    microdelay = ((milliSecondsDelay * 1000 + currentTime.tv_usec));
    final_time.tv_sec = currentTime.tv_sec + (microdelay / 1000000);
    final_time.tv_nsec = (microdelay % 1000000) * 1000;
    pthread_mutex_lock(&tsem->mutex);
    while (tsem->semval == 0) {
        err = pthread_cond_timedwait(&tsem->condition, &tsem->mutex, &final_time);
        if (err != 0) {
            tsem->semval--;
        }
    }
    tsem->semval--;
    pthread_mutex_unlock(&tsem->mutex);
    return err;
}

OSCL_EXPORT_REF void tsem_down(tsem_t* tsem) {
  pthread_mutex_lock(&tsem->mutex);
  while (tsem->semval == 0) {
    pthread_cond_wait(&tsem->condition, &tsem->mutex);
  }
  tsem->semval--;
  pthread_mutex_unlock(&tsem->mutex);
}

OSCL_EXPORT_REF void tsem_up(tsem_t* tsem) {
  pthread_mutex_lock(&tsem->mutex);
  tsem->semval++;
  pthread_cond_signal(&tsem->condition);
  pthread_mutex_unlock(&tsem->mutex);
}

OSCL_EXPORT_REF void tsem_reset(tsem_t* tsem) {
  pthread_mutex_lock(&tsem->mutex);
  tsem->semval=0;
  pthread_mutex_unlock(&tsem->mutex);
}

OSCL_EXPORT_REF void tsem_wait(tsem_t* tsem) {
  pthread_mutex_lock(&tsem->mutex);
  pthread_cond_wait(&tsem->condition, &tsem->mutex);
  pthread_mutex_unlock(&tsem->mutex);
}

OSCL_EXPORT_REF void tsem_signal(tsem_t* tsem) {
  pthread_mutex_lock(&tsem->mutex);
  pthread_cond_signal(&tsem->condition);
  pthread_mutex_unlock(&tsem->mutex);
}