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Diffstat (limited to 'libgomp/config/posix/sem.c')
-rw-r--r-- | libgomp/config/posix/sem.c | 123 |
1 files changed, 123 insertions, 0 deletions
diff --git a/libgomp/config/posix/sem.c b/libgomp/config/posix/sem.c new file mode 100644 index 000000000..e05767513 --- /dev/null +++ b/libgomp/config/posix/sem.c @@ -0,0 +1,123 @@ +/* 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 |