/* Machine-specific definition for spin locks.  MIPS 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/ormodify it under the terms of the GNU Library General Public License aspublished by the Free Software Foundation; either version 2 of theLicense, 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 ofMERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNULibrary General Public License for more details.You should have received a copy of the GNU Library General PublicLicense along with the GNU C Library; see the file COPYING.LIB.  Ifnot, 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 (register __spin_lock_t *__lock){  register int __rtn;  __asm__ __volatile (".set noreorder");#if 0  __asm__ __volatile ("lw %0,0(%1)": "=r" (__rtn) : "r" (__lock));  __asm__ __volatile ("sw %0,0(%0)": : "r" (__lock));  __asm__ __volatile ("xor %0,%1,%0": "=r" (__rtn) : "r" (__lock));#else  /* Use the Mach microkernel's emulated TAS pseudo-instruction.  */  register int __rtn __asm__ ("a0");  __asm__ __volatile (".word 0xf ! %0 " : "=r" (__rtn) : "0" (__lock));#endif  __asm__ __volatile (".set reorder");  return __rtn ^ (int) __lock;}/* Return nonzero if LOCK is locked.  */_EXTERN_INLINE int__spin_lock_locked (__spin_lock_t *__lock){  return *__lock != 0;}#endif /* machine-lock.h */