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-rw-r--r--libgomp/config/posix/bar.c111
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+/* Copyright (C) 2005 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 implementation of a barrier synchronization mechanism
+ for libgomp. This type is private to the library. Note that we rely on
+ being able to adjust the barrier count while threads are blocked, so the
+ POSIX pthread_barrier_t won't work. */
+
+#include "libgomp.h"
+
+
+void
+gomp_barrier_init (gomp_barrier_t *bar, unsigned count)
+{
+ gomp_mutex_init (&bar->mutex1);
+#ifndef HAVE_SYNC_BUILTINS
+ gomp_mutex_init (&bar->mutex2);
+#endif
+ gomp_sem_init (&bar->sem1, 0);
+ gomp_sem_init (&bar->sem2, 0);
+ bar->total = count;
+ bar->arrived = 0;
+}
+
+void
+gomp_barrier_destroy (gomp_barrier_t *bar)
+{
+ /* Before destroying, make sure all threads have left the barrier. */
+ gomp_mutex_lock (&bar->mutex1);
+ gomp_mutex_unlock (&bar->mutex1);
+
+ gomp_mutex_destroy (&bar->mutex1);
+#ifndef HAVE_SYNC_BUILTINS
+ gomp_mutex_destroy (&bar->mutex2);
+#endif
+ gomp_sem_destroy (&bar->sem1);
+ gomp_sem_destroy (&bar->sem2);
+}
+
+void
+gomp_barrier_reinit (gomp_barrier_t *bar, unsigned count)
+{
+ gomp_mutex_lock (&bar->mutex1);
+ bar->total = count;
+ gomp_mutex_unlock (&bar->mutex1);
+}
+
+void
+gomp_barrier_wait_end (gomp_barrier_t *bar, bool last)
+{
+ unsigned int n;
+
+ if (last)
+ {
+ n = --bar->arrived;
+ if (n > 0)
+ {
+ do
+ gomp_sem_post (&bar->sem1);
+ while (--n != 0);
+ gomp_sem_wait (&bar->sem2);
+ }
+ gomp_mutex_unlock (&bar->mutex1);
+ }
+ else
+ {
+ gomp_mutex_unlock (&bar->mutex1);
+ gomp_sem_wait (&bar->sem1);
+
+#ifdef HAVE_SYNC_BUILTINS
+ n = __sync_add_and_fetch (&bar->arrived, -1);
+#else
+ gomp_mutex_lock (&bar->mutex2);
+ n = --bar->arrived;
+ gomp_mutex_unlock (&bar->mutex2);
+#endif
+
+ if (n == 0)
+ gomp_sem_post (&bar->sem2);
+ }
+}
+
+void
+gomp_barrier_wait (gomp_barrier_t *barrier)
+{
+ gomp_barrier_wait_end (barrier, gomp_barrier_wait_start (barrier));
+}