Return to mutex.h CVS log

Up to [local] / sys / sys

Annotation of sys/sys/mutex.h, Revision 1.1.1.1

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