Add a generic memory.h file based on gcc's __sync functions.

libpthread/

2008-12-17  Neal H. Walfield  <neal@gnu.org>

	* sysdeps/generic/bits/memory.h: New file.

1 files changed, 36 insertions, 0 deletions

diff --git a/libpthread/sysdeps/generic/bits/memory.h b/libpthread/sysdeps/generic/bits/memory.h
new file mode 100644
index 0000000..7b88a7e
--- /dev/null
+++ b/libpthread/sysdeps/generic/bits/memory.h
@@ -0,0 +1,36 @@
+/* Memory barrier operations.  Generic version.
+   Copyright (C) 2008 Free Software Foundation, Inc.
+   This file is part of the GNU Hurd.
+
+   The GNU Hurd 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 of the
+   License, or (at your option) any later version.
+
+   The GNU Hurd 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.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#ifndef _BITS_MEMORY_H
+#define _BITS_MEMORY_H	1
+
+/* Prevent read and write reordering across this function.  */
+static inline void
+__memory_barrier (void)
+{
+  /* Any lock'ed instruction will do.  */
+  __sync_synchronize ();
+}
+
+/* Prevent read reordering across this function.  */
+#define __memory_read_barrier __memory_barrier
+
+/* Prevent write reordering across this function.  */
+#define __memory_write_barrier __memory_barrier
+
+#endif