124 lines
2.8 KiB
C
124 lines
2.8 KiB
C
/* Copyright (C) 2005-2013 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
|