147 lines
4.4 KiB
C
147 lines
4.4 KiB
C
/*
|
|
* -------------------------------------------------------------
|
|
*
|
|
* 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)
|
|
*
|
|
* -------------------------------------------------------------
|
|
*
|
|
* --------------------------------------------------------------------------
|
|
*
|
|
* Pthreads-win32 - POSIX Threads Library for Win32
|
|
* Copyright(C) 1998 John E. Bossom
|
|
* Copyright(C) 1999,2005 Pthreads-win32 contributors
|
|
*
|
|
* Contact Email: rpj@callisto.canberra.edu.au
|
|
*
|
|
* 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:
|
|
* http://sources.redhat.com/pthreads-win32/contributors.html
|
|
*
|
|
* This library is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU Lesser General Public
|
|
* License as published by the Free Software Foundation; either
|
|
* version 2 of the License, or (at your option) any later version.
|
|
*
|
|
* This library is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
* Lesser General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU Lesser General Public
|
|
* License along with this library in the file COPYING.LIB;
|
|
* if not, write to the Free Software Foundation, Inc.,
|
|
* 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
|
|
*/
|
|
|
|
#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
|
|
{
|
|
s = *sem;
|
|
*sem = NULL;
|
|
|
|
if ((result = pthread_mutex_trylock (&s->lock)) == 0)
|
|
{
|
|
if (s->value >= 0)
|
|
{
|
|
(void) pthread_mutex_unlock (&s->lock);
|
|
|
|
if (!CloseHandle (s->sem))
|
|
{
|
|
*sem = s;
|
|
result = EINVAL;
|
|
}
|
|
else if ((result = pthread_mutex_destroy (&s->lock)) != 0)
|
|
{
|
|
|
|
#ifdef NEED_SEM
|
|
s->sem = CreateEvent (NULL,
|
|
PTW32_FALSE, /* manual reset is false */
|
|
PTW32_FALSE, /* initial state is unset */
|
|
NULL);
|
|
#else
|
|
s->sem = CreateSemaphore (NULL, /* Always NULL */
|
|
(long) 0, /* Force threads to wait */
|
|
(long) _POSIX_SEM_VALUE_MAX, /* Maximum value */
|
|
NULL); /* Name */
|
|
#endif
|
|
|
|
if (s->sem == 0)
|
|
{
|
|
/* We just have to pretend that we've destroyed the semaphore
|
|
* even though we're leaving a mutex around.
|
|
*/
|
|
result = 0;
|
|
}
|
|
else
|
|
{
|
|
*sem = s;
|
|
if (result != EBUSY)
|
|
result = EINVAL;
|
|
}
|
|
}
|
|
}
|
|
else
|
|
{
|
|
(void) pthread_mutex_unlock (&s->lock);
|
|
result = EBUSY;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (result != 0)
|
|
{
|
|
errno = result;
|
|
return -1;
|
|
}
|
|
|
|
free (s);
|
|
|
|
return 0;
|
|
|
|
} /* sem_destroy */
|