condvar.h revision 331722 
1/*-
2 * Copyright (c) 2000 Jake Burkholder <jake@freebsd.org>.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 * $FreeBSD: stable/11/sys/sys/condvar.h 331722 2018-03-29 02:50:57Z eadler $
27 */
28
29#ifndef	_SYS_CONDVAR_H_
30#define	_SYS_CONDVAR_H_
31
32#ifndef	LOCORE
33#include <sys/queue.h>
34
35struct lock_object;
36struct thread;
37
38TAILQ_HEAD(cv_waitq, thread);
39
40/*
41 * Condition variable.  The waiters count is protected by the mutex that
42 * protects the condition; that is, the mutex that is passed to cv_wait*()
43 * and is held across calls to cv_signal() and cv_broadcast().  It is an
44 * optimization to avoid looking up the sleep queue if there are no waiters.
45 */
46struct cv {
47	const char	*cv_description;
48	int		cv_waiters;
49};
50
51#ifdef _KERNEL
52void	cv_init(struct cv *cvp, const char *desc);
53void	cv_destroy(struct cv *cvp);
54
55void	_cv_wait(struct cv *cvp, struct lock_object *lock);
56void	_cv_wait_unlock(struct cv *cvp, struct lock_object *lock);
57int	_cv_wait_sig(struct cv *cvp, struct lock_object *lock);
58int	_cv_timedwait_sbt(struct cv *cvp, struct lock_object *lock,
59	    sbintime_t sbt, sbintime_t pr, int flags);
60int	_cv_timedwait_sig_sbt(struct cv *cvp, struct lock_object *lock,
61	    sbintime_t sbt, sbintime_t pr, int flags);
62
63void	cv_signal(struct cv *cvp);
64void	cv_broadcastpri(struct cv *cvp, int pri);
65
66#define	cv_wait(cvp, lock)						\
67	_cv_wait((cvp), &(lock)->lock_object)
68#define	cv_wait_unlock(cvp, lock)					\
69	_cv_wait_unlock((cvp), &(lock)->lock_object)
70#define	cv_wait_sig(cvp, lock)						\
71	_cv_wait_sig((cvp), &(lock)->lock_object)
72#define	cv_timedwait(cvp, lock, timo)					\
73	_cv_timedwait_sbt((cvp), &(lock)->lock_object,			\
74	    tick_sbt * (timo), 0, C_HARDCLOCK)
75#define	cv_timedwait_sbt(cvp, lock, sbt, pr, flags)			\
76	_cv_timedwait_sbt((cvp), &(lock)->lock_object, (sbt), (pr), (flags))
77#define	cv_timedwait_sig(cvp, lock, timo)				\
78	_cv_timedwait_sig_sbt((cvp), &(lock)->lock_object,		\
79	    tick_sbt * (timo), 0, C_HARDCLOCK)
80#define	cv_timedwait_sig_sbt(cvp, lock, sbt, pr, flags)			\
81	_cv_timedwait_sig_sbt((cvp), &(lock)->lock_object, (sbt), (pr), (flags))
82
83#define cv_broadcast(cvp)	cv_broadcastpri(cvp, 0)
84
85#define	cv_wmesg(cvp)		((cvp)->cv_description)
86
87#endif	/* _KERNEL */
88#endif	/* !LOCORE */
89#endif	/* _SYS_CONDVAR_H_ */
90