1 files changed, 65 insertions, 0 deletions
diff --git a/gcc-4.2.1-5666.3/libgomp/config/linux/sem.c b/gcc-4.2.1-5666.3/libgomp/config/linux/sem.c
new file mode 100644
index 000000000..798e3f1f2
--- /dev/null
+++ b/gcc-4.2.1-5666.3/libgomp/config/linux/sem.c
@@ -0,0 +1,65 @@
+/* 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 semaphore 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"
+
+
+void
+gomp_sem_wait_slow (gomp_sem_t *sem)
+{
+  while (1)
+    {
+      int val = __sync_val_compare_and_swap (sem, 0, -1);
+      if (val > 0)
+	{
+	  if (__sync_bool_compare_and_swap (sem, val, val - 1))
+	    return;
+	}
+      futex_wait (sem, -1);
+    }
+}
+
+void
+gomp_sem_post_slow (gomp_sem_t *sem)
+{
+  int old, tmp = *sem, wake;
+
+  do
+    {
+      old = tmp;
+      wake = old > 0 ? old + 1 : 1;
+      tmp = __sync_val_compare_and_swap (sem, old, wake);
+    }
+  while (old != tmp);
+
+  futex_wake (sem, wake);
+}