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/* Copyright (C) 2005-2022 Free Software Foundation, Inc. Contributed by Richard Henderson <rth@redhat.com>.
This file is part of the GNU Offloading and Multi Processing 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; }
int gomp_sem_getcount (gomp_sem_t *sem) { int ret, count;
ret = pthread_mutex_lock (&sem->mutex); if (ret) return -1;
count = sem->value;
ret = pthread_mutex_unlock (&sem->mutex); if (ret) return -1;
if (count < 0) return -1;
return count; } #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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