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/*
* Mach Operating System
* Copyright (c) 1993,1991,1990 Carnegie Mellon University
* All Rights Reserved.
*
* Permission to use, copy, modify and distribute this software and its
* documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation.
*
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
* ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
*
* Carnegie Mellon requests users of this software to return to
*
* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
* School of Computer Science
* Carnegie Mellon University
* Pittsburgh PA 15213-3890
*
* any improvements or extensions that they make and grant Carnegie Mellon
* the rights to redistribute these changes.
*/
/*
* HISTORY
* $Log: cthreads.h,v $
* Revision 2.9 93/01/24 13:24:58 danner
* Move ! in spin_try_lock to give the compiler
* a fighting chance.
* [92/11/19 rvb]
*
* Revision 2.8 93/01/14 18:05:09 danner
* asm -> __asm__
* [93/01/10 danner]
*
* Revision 2.7 92/01/03 20:36:59 dbg
* Add volatile to spin_lock_t. Change spin_unlock and
* spin_try_lock definitions back to memory operands, but rely on
* volatile attribute to keep from using value in memory.
* [91/09/04 dbg]
*
* Revision 2.6 91/08/28 20:18:39 jsb
* Safer definitions for spin_unlock and spin_try_lock from mib.
*
* Revision 2.5 91/07/31 18:36:49 dbg
* Add inline substitution for cthread_sp, spin_unlock,
* spin_try_lock.
* [91/07/30 17:35:53 dbg]
*
* Revision 2.4 91/05/14 17:57:11 mrt
* Correcting copyright
*
* Revision 2.3 91/02/14 14:20:14 mrt
* Changed to new Mach copyright
* [91/02/13 12:20:00 mrt]
*
* Revision 2.2 90/11/05 14:37:23 rpd
* Created.
* [90/11/01 rwd]
*
*
*/
#ifndef _MACHINE_CTHREADS_H_
#define _MACHINE_CTHREADS_H_
typedef volatile int spin_lock_t;
#define SPIN_LOCK_INITIALIZER 0
#define spin_lock_init(s) (*(s) = 0)
#define spin_lock_locked(s) (*(s) != 0)
#ifdef __GNUC__
#define spin_unlock(p) \
({ register int _u__ ; \
__asm__ volatile("xorl %0, %0; \n\
xchgl %0, %1" \
: "=&r" (_u__), "=m" (*(p)) ); \
0; })
#define spin_try_lock(p)\
(!({ boolean_t _r__; \
__asm__ volatile("movl $1, %0; \n\
xchgl %0, %1" \
: "=&r" (_r__), "=m" (*(p)) ); \
_r__; }))
#define cthread_sp() \
({ int _sp__; \
__asm__("movl %%esp, %0" \
: "=g" (_sp__) ); \
_sp__; })
#endif /* __GNUC__ */
#endif _MACHINE_CTHREADS_H_
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