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Diffstat (limited to 'sysdeps/generic/machine-lock.h')
-rw-r--r-- | sysdeps/generic/machine-lock.h | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/sysdeps/generic/machine-lock.h b/sysdeps/generic/machine-lock.h new file mode 100644 index 0000000000..3776bb0049 --- /dev/null +++ b/sysdeps/generic/machine-lock.h @@ -0,0 +1,64 @@ +/* Machine-specific definition for spin locks. Stub version. + Copyright (C) 1994, 1997 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., 59 Temple Place - Suite 330, + Boston, MA 02111-1307, 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 */ |