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/*
* Mach Operating System
* Copyright (c) 1992,1991,1990,1989 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: sync.c,v $
* Revision 2.8 93/01/14 18:06:23 danner
* Converted file to ANSI C.
* [92/12/18 pds]
*
* Revision 2.7 92/03/06 14:09:59 rpd
* Replaced swtch_pri with yield.
* [92/03/06 rpd]
*
* Revision 2.6 91/05/14 17:59:54 mrt
* Correcting copyright
*
* Revision 2.5 91/02/14 14:21:38 mrt
* Added new Mach copyright
* [91/02/13 12:41:42 mrt]
*
* Revision 2.4 90/11/05 14:38:08 rpd
* Fix casting. Use new macros.
* [90/10/31 rwd]
*
* Revision 2.3 90/08/07 14:31:50 rpd
* Removed RCS keyword nonsense.
*
* Revision 2.2 89/12/08 19:55:01 rwd
* Changed spin_lock to spin_lock_solid to optimize.
* [89/11/13 rwd]
* Added copyright. Move mutexes to cproc.c. Spin locks are now
* old mutexes.
* [89/10/23 rwd]
*
*/
/*
* sync.c
*
* Spin locks
*/
#include <cthreads.h>
#include "cthread_internals.h"
/*
* Spin locks.
* Use test and test-and-set logic on all architectures.
*/
int cthread_spin_count=0;
void
spin_lock_solid(register spin_lock_t *p)
{
while (spin_lock_locked(p) || !spin_try_lock(p)) {
#ifdef STATISTICS
cthread_spin_count++;
#endif
#ifdef SPIN_RESCHED
yield();
#endif
}
}
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