glibc/sysdeps/mach/hppa/machine-lock.h

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1995-02-08 03:06:52 +00:00
/* Machine-specific definition for spin locks. HPPA version.
Copyright (C) 1995 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 __attribute__ ((__aligned__ (16)));
/* Value to initialize `__spin_lock_t' variables to. */
#define __SPIN_LOCK_INITIALIZER -1
#ifndef _EXTERN_INLINE
#define _EXTERN_INLINE extern __inline
#endif
/* Unlock LOCK. */
_EXTERN_INLINE void
__spin_unlock (__spin_lock_t *__lock)
{
*__lock = -1;
}
/* 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 __result;
__asm__ __volatile__ ("ldcws %0, %1" : "=m" (*__lock), "=r" (__result));
return __result != 0;
}
/* Return nonzero if LOCK is locked. */
_EXTERN_INLINE int
__spin_lock_locked (__spin_lock_t *__lock)
{
return *__lock == 0;
}
#endif /* machine-lock.h */