2008-06-06 Basile Starynkevitch <basile@starynkevitch.net>

	MELT branch merged with trunk r136492



git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/branches/melt-branch@136504 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 65 insertions, 0 deletions

diff --git a/libgomp/config/linux/ptrlock.h b/libgomp/config/linux/ptrlock.h
new file mode 100644
index 00000000000..bb5441676a4
--- /dev/null
+++ b/libgomp/config/linux/ptrlock.h
@@ -0,0 +1,65 @@
+/* Copyright (C) 2008 Free Software Foundation, Inc.
+   Contributed by Jakub Jelinek <jakub@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 mutex synchronization
+   mechanism for libgomp.  This type is private to the library.  This
+   implementation uses atomic instructions and the futex syscall.  */
+
+#ifndef GOMP_PTRLOCK_H
+#define GOMP_PTRLOCK_H 1
+
+typedef void *gomp_ptrlock_t;
+
+static inline void gomp_ptrlock_init (gomp_ptrlock_t *ptrlock, void *ptr)
+{
+  *ptrlock = ptr;
+}
+
+extern void *gomp_ptrlock_get_slow (gomp_ptrlock_t *ptrlock);
+static inline void *gomp_ptrlock_get (gomp_ptrlock_t *ptrlock)
+{
+  if ((uintptr_t) *ptrlock > 2)
+    return *ptrlock;
+
+  if (__sync_bool_compare_and_swap (ptrlock, NULL, (uintptr_t) 1))
+    return NULL;
+
+  return gomp_ptrlock_get_slow (ptrlock);
+}
+
+extern void gomp_ptrlock_set_slow (gomp_ptrlock_t *ptrlock, void *ptr);
+static inline void gomp_ptrlock_set (gomp_ptrlock_t *ptrlock, void *ptr)
+{
+  if (!__sync_bool_compare_and_swap (ptrlock, (uintptr_t) 1, ptr))
+    gomp_ptrlock_set_slow (ptrlock, ptr);
+}
+
+static inline void gomp_ptrlock_destroy (gomp_ptrlock_t *ptrlock)
+{
+}
+
+#endif /* GOMP_PTRLOCK_H */