int
sem_post_multiple (sem_t * sem, int count )
/*
* ------------------------------------------------------
* DOCPUBLIC
* This function posts multiple wakeups to a semaphore.
*
* PARAMETERS
* sem
* pointer to an instance of sem_t
*
* count
* counter, must be greater than zero.
*
* DESCRIPTION
* This function posts multiple wakeups to a semaphore. If there
* are waiting threads (or processes), n <= count are awakened;
* the semaphore value is incremented by count - n.
*
* RESULTS
* 0 successfully posted semaphore,
* -1 failed, error in errno
* ERRNO
* EINVAL 'sem' is not a valid semaphore
* or count is less than or equal to zero.
*
* ------------------------------------------------------
*/
{
int result = 0;
if (sem == NULL || *sem == NULL || count <= 0)
{
result = EINVAL;
}
#ifdef NEED_SEM
else if (! ptw32_increase_semaphore (sem, count))
#else /* NEED_SEM */
else if (! ReleaseSemaphore ((*sem)->sem, count, 0))
#endif /* NEED_SEM */
{
result = EINVAL;
}
if (result != 0)
{
errno = result;
return -1;
}
return 0;
} /* sem_post_multiple */
int
sem_post (sem_t * sem)
/*
* ------------------------------------------------------
* DOCPUBLIC
* This function posts a wakeup to a semaphore.
*
* PARAMETERS
* sem
* pointer to an instance of sem_t
*
* DESCRIPTION
* This function posts a wakeup to a semaphore. If there
* are waiting threads (or processes), one is awakened;
* otherwise, the semaphore value is incremented by one.
*
* RESULTS
* 0 successfully posted semaphore,
* -1 failed, error in errno
* ERRNO
* EINVAL 'sem' is not a valid semaphore,
* ENOSYS semaphores are not supported,
*
* ------------------------------------------------------
*/
{
int result = 0;
if (sem == NULL || *sem == NULL)
{
result = EINVAL;
}
#ifdef NEED_SEM
else if (!ptw32_increase_semaphore (sem, 1))
#else /* NEED_SEM */
else if (!ReleaseSemaphore ((*sem)->sem, 1, 0))
#endif /* NEED_SEM */
{
result = EINVAL;
}
if (result != 0)
{
errno = result;
return -1;
}
return 0;
} /* sem_post */
int
sem_post_multiple (sem_t * sem, int count)
/*
* ------------------------------------------------------
* DOCPUBLIC
* This function posts multiple wakeups to a semaphore.
*
* PARAMETERS
* sem
* pointer to an instance of sem_t
*
* count
* counter, must be greater than zero.
*
* DESCRIPTION
* This function posts multiple wakeups to a semaphore. If there
* are waiting threads (or processes), n <= count are awakened;
* the semaphore value is incremented by count - n.
*
* RESULTS
* 0 successfully posted semaphore,
* -1 failed, error in errno
* ERRNO
* EINVAL 'sem' is not a valid semaphore
* or count is less than or equal to zero.
*
* ------------------------------------------------------
*/
{
int result = 0;
#ifndef NEED_SEM
long waiters;
sem_t s = *sem;
#endif
if (s == NULL || count <= 0)
{
result = EINVAL;
}
#ifdef NEED_SEM
else if (!ptw32_increase_semaphore (sem, count))
{
result = EINVAL;
}
#else /* NEED_SEM */
else if ((result = pthread_mutex_lock (&s->lock)) == 0)
{
waiters = -s->value;
s->value += count;
if (waiters > 0)
{
if (!ReleaseSemaphore (s->sem, (waiters<=count)?waiters:count, 0))
{
result = EINVAL;
}
}
(void) pthread_mutex_unlock (&s->lock);
}
#endif /* NEED_SEM */
if (result != 0)
{
errno = result;
return -1;
}
return 0;
} /* sem_post_multiple */
