1 files changed, 64 insertions, 0 deletions
diff --git a/libgomp/config/linux/bar.c b/libgomp/config/linux/bar.c
new file mode 100644
index 00000000000..5c4f32e6f8b
--- /dev/null
+++ b/libgomp/config/linux/bar.c
@@ -0,0 +1,64 @@
+/* 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 a Linux specific implementation of a barrier synchronization
+   mechanism for libgomp.  This type is private to the library.  This 
+   implementation uses atomic instructions and the futex syscall.  */
+
+#include "libgomp.h"
+#include "futex.h"
+#include <limits.h>
+
+
+void
+gomp_barrier_wait_end (gomp_barrier_t *bar, bool last)
+{
+  if (last)
+    {
+      bar->generation++;
+      futex_wake (&bar->generation, INT_MAX);
+    }
+  else
+    {
+      unsigned int generation = bar->generation;
+
+      gomp_mutex_unlock (&bar->mutex);
+
+      do
+	futex_wait (&bar->generation, generation);
+      while (bar->generation == generation);
+    }
+
+  if (__sync_add_and_fetch (&bar->arrived, -1) == 0)
+    gomp_mutex_unlock (&bar->mutex);
+}
+
+void
+gomp_barrier_wait (gomp_barrier_t *barrier)
+{
+  gomp_barrier_wait_end (barrier, gomp_barrier_wait_start (barrier));
+}