/*
* -------------------------------------------------------------
*
* Module: sem_destroy.c
*
* Purpose:
* Semaphores aren't actually part of the PThreads standard.
* They are defined by the POSIX Standard:
*
* POSIX 1003.1b-1993 (POSIX.1b)
*
* -------------------------------------------------------------
*
* --------------------------------------------------------------------------
*
* Pthreads4w - POSIX Threads for Windows
* Copyright 1998 John E. Bossom
* Copyright 1999-2018, Pthreads4w contributors
*
* Homepage: https://sourceforge.net/projects/pthreads4w/
*
* The current list of contributors is contained
* in the file CONTRIBUTORS included with the source
* code distribution. The list can also be seen at the
* following World Wide Web location:
*
* https://sourceforge.net/p/pthreads4w/wiki/Contributors/
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include "pthread.h"
#include "semaphore.h"
#include "implement.h"
int
sem_destroy (sem_t * sem)
/*
* ------------------------------------------------------
* DOCPUBLIC
* This function destroys an unnamed semaphore.
*
* PARAMETERS
* sem
* pointer to an instance of sem_t
*
* DESCRIPTION
* This function destroys an unnamed semaphore.
*
* RESULTS
* 0 successfully destroyed semaphore,
* -1 failed, error in errno
* ERRNO
* EINVAL 'sem' is not a valid semaphore,
* ENOSYS semaphores are not supported,
* EBUSY threads (or processes) are currently
* blocked on 'sem'
*
* ------------------------------------------------------
*/
{
int result = 0;
sem_t s = NULL;
if (sem == NULL || *sem == NULL)
{
result = EINVAL;
}
else
{
__ptw32_mcs_local_node_t node;
s = *sem;
if ((result = __ptw32_mcs_lock_try_acquire(&s->lock, &node)) == 0)
{
if (s->value < 0)
{
result = EBUSY;
}
else
{
/*
* There are no threads currently blocked on this semaphore
* however there could be threads about to wait behind us.
* It is up to the application to ensure this is not the case.
*/
if (!CloseHandle (s->sem))
{
result = EINVAL;
}
}
__ptw32_mcs_lock_release(&node);
}
}
if (result != 0)
{
__PTW32_SET_ERRNO(result);
return -1;
}
free (s);
return 0;
} /* sem_destroy */
