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authorRoland McGrath <roland@gnu.org>1995-02-18 01:27:10 +0000
committerRoland McGrath <roland@gnu.org>1995-02-18 01:27:10 +0000
commit28f540f45bbacd939bfd07f213bcad2bf730b1bf (patch)
tree15f07c4c43d635959c6afee96bde71fb1b3614ee /sysdeps/stub/machine-lock.h
initial import
Diffstat (limited to 'sysdeps/stub/machine-lock.h')
-rw-r--r--sysdeps/stub/machine-lock.h64
1 files changed, 64 insertions, 0 deletions
diff --git a/sysdeps/stub/machine-lock.h b/sysdeps/stub/machine-lock.h
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+++ b/sysdeps/stub/machine-lock.h
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+/* Machine-specific definition for spin locks. Stub version.
+Copyright (C) 1994 Free Software Foundation, Inc.
+This file is part of the GNU C Library.
+
+The GNU C Library is free software; you can redistribute it and/or
+modify it under the terms of the GNU Library General Public License as
+published by the Free Software Foundation; either version 2 of the
+License, or (at your option) any later version.
+
+The GNU C Library 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
+Library General Public License for more details.
+
+You should have received a copy of the GNU Library General Public
+License along with the GNU C Library; see the file COPYING.LIB. If
+not, write to the Free Software Foundation, Inc., 675 Mass Ave,
+Cambridge, MA 02139, USA. */
+
+#ifndef _MACHINE_LOCK_H
+#define _MACHINE_LOCK_H
+
+/* The type of a spin lock variable. */
+
+typedef volatile int __spin_lock_t;
+
+/* Value to initialize `__spin_lock_t' variables to. */
+
+#define __SPIN_LOCK_INITIALIZER 0
+
+
+#ifndef _EXTERN_INLINE
+#define _EXTERN_INLINE extern __inline
+#endif
+
+/* Unlock LOCK. */
+
+_EXTERN_INLINE void
+__spin_unlock (__spin_lock_t *__lock)
+{
+ *__lock = 0;
+}
+
+/* Try to lock LOCK; return nonzero if we locked it, zero if another has. */
+
+_EXTERN_INLINE int
+__spin_try_lock (__spin_lock_t *__lock)
+{
+ if (*__lock)
+ return 0;
+ *__lock = 1;
+ return 1;
+}
+
+/* Return nonzero if LOCK is locked. */
+
+_EXTERN_INLINE int
+__spin_lock_locked (__spin_lock_t *__lock)
+{
+ return *__lock != 0;
+}
+
+
+#endif /* machine-lock.h */