/*-
* 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.
*
* $FreeBSD$
*/
#ifndef _SYS__MUTEX_H_
#define _SYS__MUTEX_H_
#include <machine/param.h>
/*
* Sleep/spin mutex.
*
* All mutex implementations must always have a member called mtx_lock.
* Other locking primitive structures are not allowed to use this name
* for their members.
* If this rule needs to change, the bits in the mutex implementation must
* be modified appropriately.
*/
struct mtx {
struct lock_object lock_object; /* Common lock properties. */
volatile uintptr_t mtx_lock; /* Owner and flags. */
};
/*
* Members of struct mtx_padalign must mirror members of struct mtx.
* mtx_padalign mutexes can use the mtx(9) API transparently without
* modification.
* Pad-aligned mutexes used within structures should generally be the
* first member of the struct. Otherwise, the compiler can generate
* additional padding for the struct to keep a correct alignment for
* the mutex.
*/
struct mtx_padalign {
struct lock_object lock_object; /* Common lock properties. */
volatile uintptr_t mtx_lock; /* Owner and flags. */
} __aligned(CACHE_LINE_SIZE);
#endif /* !_SYS__MUTEX_H_ */