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#include "Thread.h"
#include "Timespec.h"
#include <stdlib.h>
#include <errno.h>
#include <time.h>
#if (_POSIX_SEMAPHORES >= 200112L)
BH_Semaphore *BH_SemaphoreNew(int value)
{
BH_Semaphore *semaphore;
/* Allocate space for mutex and initialize it */
semaphore = malloc(sizeof(BH_Semaphore));
if (semaphore && sem_init(&semaphore->handle, 0, value))
{
free(semaphore);
return NULL;
}
return semaphore;
}
void BH_SemaphoreFree(BH_Semaphore *semaphore)
{
sem_destroy(&semaphore->handle);
free(semaphore);
}
int BH_SemaphorePost(BH_Semaphore *semaphore)
{
if (sem_post(&semaphore->handle))
return BH_ERROR;
return BH_OK;
}
int BH_SemaphoreWait(BH_Semaphore *semaphore)
{
if (sem_wait(&semaphore->handle))
return BH_ERROR;
return BH_OK;
}
int BH_SemaphoreTryWait(BH_Semaphore *semaphore)
{
if (sem_trywait(&semaphore->handle))
return BH_ERROR;
return BH_OK;
}
int BH_SemaphoreWaitFor(BH_Semaphore *semaphore,
uint32_t timeout)
{
struct timespec ts;
if (convertToTimespec(&ts, timeout))
return BH_ERROR;
switch (sem_timedwait(&semaphore->handle, &ts))
{
case 0: return BH_OK;
case ETIMEDOUT: return BH_TIMEOUT;
default: return BH_ERROR;
}
}
#else
BH_Semaphore *BH_SemaphoreNew(int value)
{
BH_Semaphore *semaphore;
/* Allocate space for mutex and initialize it */
semaphore = malloc(sizeof(BH_Semaphore));
if (semaphore)
{
semaphore->count = value;
semaphore->waiters = 0;
if (pthread_mutex_init(&semaphore->mutex, NULL))
{
free(semaphore);
return NULL;
}
if (pthread_cond_init(&semaphore->condition, NULL))
{
pthread_mutex_destroy(&semaphore->mutex);
free(semaphore);
return NULL;
}
}
return semaphore;
}
void BH_SemaphoreFree(BH_Semaphore *semaphore)
{
/* Destroy condition variable and mutex */
pthread_cond_destroy(&semaphore->condition);
pthread_mutex_destroy(&semaphore->mutex);
free(semaphore);
}
int BH_SemaphorePost(BH_Semaphore *semaphore)
{
int result;
/* Increase semaphore value */
if (pthread_mutex_lock(&semaphore->mutex))
return BH_ERROR;
result = BH_OK;
semaphore->count++;
if (semaphore->waiters && pthread_cond_signal(&semaphore->condition))
result = BH_ERROR;
pthread_mutex_unlock(&semaphore->mutex);
return result;
}
int BH_SemaphoreWait(BH_Semaphore *semaphore)
{
int result;
/* Wait until semaphore count is not zero */
if (pthread_mutex_lock(&semaphore->mutex))
return BH_ERROR;
result = BH_OK;
semaphore->waiters++;
while (!semaphore->count) {
result = pthread_cond_wait(&semaphore->condition, &semaphore->mutex);
if (result && result != ETIMEDOUT) {
result = BH_ERROR;
break;
}
result = BH_OK;
}
semaphore->waiters--;
semaphore->count--;
pthread_mutex_unlock(&semaphore->mutex);
return result;
}
int BH_SemaphoreTryWait(BH_Semaphore *semaphore)
{
int result;
result = BH_OK;
/* Check if semaphore count is not zero and decrement it */
pthread_mutex_lock(&semaphore->mutex);
if (!semaphore->count)
result = BH_ERROR;
else
semaphore->count--;
pthread_mutex_unlock(&semaphore->mutex);
return result;
}
int BH_SemaphoreWaitFor(BH_Semaphore *semaphore,
uint32_t timeout)
{
int result;
struct timespec ts;
/* Calculate absoulute time for timed wait */
if (convertToTimespec(&ts, timeout))
return BH_ERROR;
result = BH_OK;
/* Wait until semaphore count is not zero or timeout */
pthread_mutex_lock(&semaphore->mutex);
semaphore->waiters++;
while (!semaphore->count && result == BH_OK)
{
switch (pthread_cond_timedwait(&semaphore->condition, &semaphore->mutex, &ts))
{
case 0: result = BH_OK; break;
case ETIMEDOUT: result = BH_TIMEOUT; break;
default: result = BH_ERROR; break;
}
}
semaphore->waiters--;
/* If everything went fine - decrement semaphore counter */
if (!result)
semaphore->count--;
pthread_mutex_unlock(&semaphore->mutex);
return result;
}
#endif
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