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author | Roland McGrath <roland@gnu.org> | 1995-02-18 01:27:10 +0000 |
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committer | Roland McGrath <roland@gnu.org> | 1995-02-18 01:27:10 +0000 |
commit | 28f540f45bbacd939bfd07f213bcad2bf730b1bf (patch) | |
tree | 15f07c4c43d635959c6afee96bde71fb1b3614ee /sysdeps/mach/i386/machine-lock.h | |
download | glibc-28f540f45bbacd939bfd07f213bcad2bf730b1bf.zip glibc-28f540f45bbacd939bfd07f213bcad2bf730b1bf.tar.gz glibc-28f540f45bbacd939bfd07f213bcad2bf730b1bf.tar.bz2 |
initial import
Diffstat (limited to 'sysdeps/mach/i386/machine-lock.h')
-rw-r--r-- | sysdeps/mach/i386/machine-lock.h | 66 |
1 files changed, 66 insertions, 0 deletions
diff --git a/sysdeps/mach/i386/machine-lock.h b/sysdeps/mach/i386/machine-lock.h new file mode 100644 index 0000000..bdc57e0 --- /dev/null +++ b/sysdeps/mach/i386/machine-lock.h @@ -0,0 +1,66 @@ +/* Machine-specific definition for spin locks. i386 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) +{ + register int __unlocked; + __asm__ __volatile ("xchgl %0, %1" + : "=&r" (__unlocked), "=m" (*__lock) : "0" (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) +{ + register int __locked; + __asm__ __volatile ("xchgl %0, %1" + : "=&r" (__locked), "=m" (*__lock) : "0" (1)); + return !__locked; +} + +/* Return nonzero if LOCK is locked. */ + +_EXTERN_INLINE int +__spin_lock_locked (__spin_lock_t *__lock) +{ + return *__lock != 0; +} + + +#endif /* machine-lock.h */ |