/*-

 * Copyright (c) 1997 Berkeley Software Design, Inc. All rights reserved.

 *

 * 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. Berkeley Software Design Inc's name may not be used to endorse or

 *    promote products derived from this software without specific prior

 *    written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY BERKELEY SOFTWARE DESIGN INC ``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 BERKELEY SOFTWARE DESIGN INC 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.

 *

 * $FreeBSD: src/sys/sys/_mutex.h,v 1.11 2004/01/25 01:59:26 rwatson Exp $

 */

#ifndef _SYS__MUTEX_H_

#define	_SYS__MUTEX_H_

/*

 * Sleep/spin mutex.

 */

struct mtx {

	struct lock_object	mtx_object;	/* Common lock properties. */

	volatile uintptr_t	mtx_lock;	/* Owner and flags. */

	volatile u_int		mtx_recurse;	/* Number of recursive holds. */

#ifdef MUTEX_PROFILING

	/*

	 * This does not result in variant structure sizes because

	 * MUTEX_PROFILING is in opt_global.h

	 */

	u_int64_t		mtx_acqtime;

	const char		*mtx_filename;

	int			mtx_lineno;

	/*

	 * Fields relating to measuring contention on mutexes.

	 * holding must be accessed atomically since it's

	 * modified by threads that don't yet hold the mutex.

	 * locking is only modified and referenced while

	 * the mutex is held.

	 */

	u_int			mtx_contest_holding;

	u_int			mtx_contest_locking;

#endif

};

#endif /* !_SYS__MUTEX_H_ */