minix/include/sys/lock.h

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2012-08-10 18:05:05 +02:00
/* $NetBSD: lock.h,v 1.86 2010/07/01 13:00:57 hannken Exp $ */
/*-
* Copyright (c) 1999, 2000, 2006, 2007 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
* NASA Ames Research Center, by Ross Harvey, and by Andrew Doran.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
/*
* Copyright (c) 1995
* The Regents of the University of California. All rights reserved.
*
* This code contains ideas from software contributed to Berkeley by
* Avadis Tevanian, Jr., Michael Wayne Young, and the Mach Operating
* System project at Carnegie-Mellon University.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)lock.h 8.12 (Berkeley) 5/19/95
*/
#ifndef _SYS_LOCK_H_
#define _SYS_LOCK_H_
#include <sys/stdint.h>
#include <sys/mutex.h>
#include <machine/lock.h>
#ifdef _KERNEL
/*
* From <machine/lock.h>.
*/
#ifndef SPINLOCK_SPIN_HOOK
#define SPINLOCK_SPIN_HOOK
#endif
#ifndef SPINLOCK_BACKOFF_HOOK
#define SPINLOCK_BACKOFF_HOOK nullop(NULL)
#endif
#ifndef SPINLOCK_BACKOFF_MIN
#define SPINLOCK_BACKOFF_MIN 4
#endif
#ifndef SPINLOCK_BACKOFF_MAX
#define SPINLOCK_BACKOFF_MAX 128
#endif
#define SPINLOCK_BACKOFF(count) \
do { \
int __i; \
for (__i = (count); __i != 0; __i--) { \
SPINLOCK_BACKOFF_HOOK; \
} \
if ((count) < SPINLOCK_BACKOFF_MAX) \
(count) += (count); \
} while (/* CONSTCOND */ 0);
#define SPINLOCK_RUN_HOOK(count) ((count) >= SPINLOCK_BACKOFF_MAX)
#ifdef LOCKDEBUG
#define SPINLOCK_SPINOUT(spins) ((spins)++ > 0x0fffffff)
#else
#define SPINLOCK_SPINOUT(spins) ((void)(spins), 0)
#endif
extern __cpu_simple_lock_t kernel_lock[];
#endif /* _KERNEL */
#endif /* _SYS_LOCK_H_ */