/* $OpenBSD: mutex.h,v 1.4 2010/01/10 04:07:18 kettenis Exp $ */ /* * Copyright (c) 2004 Artur Grabowski * 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. The name of the author may not be used to endorse or promote products * derived from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED ``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 AUTHOR 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. */ #ifndef _MACHINE_MUTEX_H_ #define _MACHINE_MUTEX_H_ #define MUTEX_LOCKED { 0, 0, 0, 0 } #define MUTEX_UNLOCKED { 1, 1, 1, 1 } /* Note: mtx_lock must be 16-byte aligned. */ struct mutex { volatile int mtx_lock[4]; int mtx_wantipl; int mtx_oldipl; void *mtx_owner; }; void mtx_init(struct mutex *, int); #define MUTEX_INITIALIZER(ipl) { MUTEX_UNLOCKED, (ipl), 0, NULL } #ifdef DIAGNOSTIC #define MUTEX_ASSERT_LOCKED(mtx) do { \ if ((mtx)->mtx_lock[0] == 1 && (mtx)->mtx_lock[1] == 1 && \ (mtx)->mtx_lock[2] == 1 && (mtx)->mtx_lock[3] == 1) \ panic("mutex %p not held in %s", (mtx), __func__); \ } while (0) #define MUTEX_ASSERT_UNLOCKED(mtx) do { \ if ((mtx)->mtx_lock[0] != 1 && (mtx)->mtx_lock[1] != 1 && \ (mtx)->mtx_lock[2] != 1 && (mtx)->mtx_lock[3] != 1) \ panic("mutex %p held in %s", (mtx), __func__); \ } while (0) #else #define MUTEX_ASSERT_LOCKED(mtx) do { } while (0) #define MUTEX_ASSERT_UNLOCKED(mtx) do { } while (0) #endif #define MUTEX_OLDIPL(mtx) (mtx)->mtx_oldipl #endif