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/* Copyright (C) 2005, 2006, 2009 Free Software Foundation, Inc.
Contributed by Richard Henderson <rth@redhat.com>.
This file is part of the GNU OpenMP Library (libgomp).
Libgomp is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3, or (at your option)
any later version.
Libgomp 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 General Public License for
more details.
Under Section 7 of GPL version 3, you are granted additional
permissions described in the GCC Runtime Library Exception, version
3.1, as published by the Free Software Foundation.
You should have received a copy of the GNU General Public License and
a copy of the GCC Runtime Library Exception along with this program;
see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
<http://www.gnu.org/licenses/>. */
/* This is the default POSIX 1003.1b implementation of a semaphore
synchronization mechanism for libgomp. This type is private to
the library.
This is a bit heavy weight for what we need, in that we're not
interested in sem_wait as a cancelation point, but it's not too
bad for a default. */
#include "libgomp.h"
#ifdef HAVE_BROKEN_POSIX_SEMAPHORES
#include <stdlib.h>
void gomp_sem_init (gomp_sem_t *sem, int value)
{
int ret;
ret = pthread_mutex_init (&sem->mutex, NULL);
if (ret)
return;
ret = pthread_cond_init (&sem->cond, NULL);
if (ret)
return;
sem->value = value;
}
void gomp_sem_wait (gomp_sem_t *sem)
{
int ret;
ret = pthread_mutex_lock (&sem->mutex);
if (ret)
return;
if (sem->value > 0)
{
sem->value--;
ret = pthread_mutex_unlock (&sem->mutex);
return;
}
while (sem->value <= 0)
{
ret = pthread_cond_wait (&sem->cond, &sem->mutex);
if (ret)
{
pthread_mutex_unlock (&sem->mutex);
return;
}
}
sem->value--;
ret = pthread_mutex_unlock (&sem->mutex);
return;
}
void gomp_sem_post (gomp_sem_t *sem)
{
int ret;
ret = pthread_mutex_lock (&sem->mutex);
if (ret)
return;
sem->value++;
ret = pthread_mutex_unlock (&sem->mutex);
if (ret)
return;
ret = pthread_cond_signal (&sem->cond);
return;
}
void gomp_sem_destroy (gomp_sem_t *sem)
{
int ret;
ret = pthread_mutex_destroy (&sem->mutex);
if (ret)
return;
ret = pthread_cond_destroy (&sem->cond);
return;
}
#else /* HAVE_BROKEN_POSIX_SEMAPHORES */
void
gomp_sem_wait (gomp_sem_t *sem)
{
/* With POSIX, the wait can be canceled by signals. We don't want that.
It is expected that the return value here is -1 and errno is EINTR. */
while (sem_wait (sem) != 0)
continue;
}
#endif
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