| /* Copyright (C) 2005, 2006 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 Lesser General Public License as published by |
| the Free Software Foundation; either version 2.1 of the License, 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 Lesser General Public License for |
| more details. |
| |
| You should have received a copy of the GNU Lesser General Public License |
| along with libgomp; see the file COPYING.LIB. If not, write to the |
| Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, |
| MA 02110-1301, USA. */ |
| |
| /* As a special exception, if you link this library with other files, some |
| of which are compiled with GCC, to produce an executable, this library |
| does not by itself cause the resulting executable to be covered by the |
| GNU General Public License. This exception does not however invalidate |
| any other reasons why the executable file might be covered by the GNU |
| General Public License. */ |
| |
| /* 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 |