File: [cvs.NetBSD.org] / src / sys / sys / condvar.h (download)
Revision 1.2.4.4, Thu Nov 15 11:45:29 2007 UTC (16 years, 5 months ago) by yamt
Branch: yamt-lazymbuf
Changes since 1.2.4.3: +2 -2
lines
sync with head.
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/* $NetBSD: condvar.h,v 1.2.4.4 2007/11/15 11:45:29 yamt Exp $ */
/*-
* Copyright (c) 2006, 2007 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Andrew Doran.
*
* 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the NetBSD
* Foundation, Inc. and its contributors.
* 4. Neither the name of The NetBSD Foundation nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``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 FOUNDATION OR CONTRIBUTORS
* 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 _SYS_CONDVAR_H_
#define _SYS_CONDVAR_H_
#include <sys/mutex.h>
/*
* The condition variable implementation is private to kern_condvar.c but
* the size of a kcondvar_t must remain constant. cv_waiters is protected
* both by the interlock passed to cv_wait() (increment only), and the sleep
* queue lock acquired with sleeptab_lookup() (increment and decrement).
* cv_wmesg is static and does not change throughout the life of the CV.
*/
typedef struct kcondvar {
const char *cv_wmesg; /* description for /bin/ps */
u_int cv_waiters; /* number of waiters */
} kcondvar_t;
#ifdef _KERNEL
void cv_init(kcondvar_t *, const char *);
void cv_destroy(kcondvar_t *);
void cv_wait(kcondvar_t *, kmutex_t *);
int cv_wait_sig(kcondvar_t *, kmutex_t *);
int cv_timedwait(kcondvar_t *, kmutex_t *, int);
int cv_timedwait_sig(kcondvar_t *, kmutex_t *, int);
void cv_signal(kcondvar_t *);
void cv_broadcast(kcondvar_t *);
void cv_wakeup(kcondvar_t *);
bool cv_has_waiters(kcondvar_t *);
/* The "lightning bolt", awoken once per second by the clock interrupt. */
extern kcondvar_t lbolt;
#endif /* _KERNEL */
#endif /* _SYS_CONDVAR_H_ */