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Annotation of sys/sys/mutex.h, Revision 1.1

1.1     ! nbrk        1: /*     $OpenBSD: mutex.h,v 1.4 2007/05/15 15:23:36 art Exp $   */
        !             2:
        !             3: /*
        !             4:  * Copyright (c) 2004 Artur Grabowski <art@openbsd.org>
        !             5:  * All rights reserved.
        !             6:  *
        !             7:  * Redistribution and use in source and binary forms, with or without
        !             8:  * modification, are permitted provided that the following conditions
        !             9:  * are met:
        !            10:  *
        !            11:  * 1. Redistributions of source code must retain the above copyright
        !            12:  *    notice, this list of conditions and the following disclaimer.
        !            13:  * 2. The name of the author may not be used to endorse or promote products
        !            14:  *    derived from this software without specific prior written permission.
        !            15:  *
        !            16:  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
        !            17:  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
        !            18:  * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
        !            19:  * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
        !            20:  * EXEMPLARY, OR CONSEQUENTIAL  DAMAGES (INCLUDING, BUT NOT LIMITED TO,
        !            21:  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
        !            22:  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
        !            23:  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
        !            24:  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
        !            25:  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
        !            26:  */
        !            27:
        !            28: #ifndef _SYS_MUTEX_H_
        !            29: #define _SYS_MUTEX_H_
        !            30:
        !            31: /*
        !            32:  * A mutex is:
        !            33:  *  - owned by a cpu.
        !            34:  *  - non-recursive.
        !            35:  *  - spinning.
        !            36:  *  - not providing mutual exclusion between processes, only cpus.
        !            37:  *  - providing interrupt blocking when necessary.
        !            38:  *
        !            39:  * Different mutexes can be nested, but not interleaved. This is ok:
        !            40:  * "mtx_enter(foo); mtx_enter(bar); mtx_leave(bar); mtx_leave(foo);"
        !            41:  * This is _not_ ok:
        !            42:  * "mtx_enter(foo); mtx_enter(bar); mtx_leave(foo); mtx_leave(bar);"
        !            43:  */
        !            44:
        !            45: #include <machine/mutex.h>
        !            46:
        !            47: /*
        !            48:  * Some architectures need to do magic for the ipl, so they need a macro.
        !            49:  */
        !            50: #ifndef mtx_init
        !            51: void mtx_init(struct mutex *, int);
        !            52: #endif
        !            53: void mtx_enter(struct mutex *);
        !            54: void mtx_leave(struct mutex *);
        !            55:
        !            56: #endif