1/*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2000 Jake Burkholder <jake@freebsd.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 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29#ifndef _SYS_CONDVAR_H_
30#define _SYS_CONDVAR_H_
31
32/*
33 * Condition variable. The waiters count is protected by the mutex that
34 * protects the condition; that is, the mutex that is passed to cv_wait*()
35 * and is held across calls to cv_signal() and cv_broadcast(). It is an
36 * optimization to avoid looking up the sleep queue if there are no waiters.
37 */
38struct cv {
39 const char *cv_description;
40 int cv_waiters;
41};
42
43#ifdef _KERNEL
44#include <sys/types.h>
45
46struct lock_object;
47
48void cv_init(struct cv *cvp, const char *desc);
49void cv_destroy(struct cv *cvp);
50
51void _cv_wait(struct cv *cvp, struct lock_object *lock);
52void _cv_wait_unlock(struct cv *cvp, struct lock_object *lock);
53int _cv_wait_sig(struct cv *cvp, struct lock_object *lock);
54int _cv_timedwait_sbt(struct cv *cvp, struct lock_object *lock,
55 sbintime_t sbt, sbintime_t pr, int flags);
56int _cv_timedwait_sig_sbt(struct cv *cvp, struct lock_object *lock,
57 sbintime_t sbt, sbintime_t pr, int flags);
58
59void cv_signal(struct cv *cvp);
60void cv_broadcastpri(struct cv *cvp, int pri);
61
62#define cv_wait(cvp, lock) \
63 _cv_wait((cvp), &(lock)->lock_object)
64#define cv_wait_unlock(cvp, lock) \
65 _cv_wait_unlock((cvp), &(lock)->lock_object)
66#define cv_wait_sig(cvp, lock) \
67 _cv_wait_sig((cvp), &(lock)->lock_object)
68#define cv_timedwait(cvp, lock, timo) \
69 _cv_timedwait_sbt((cvp), &(lock)->lock_object, \
70 tick_sbt * (timo), 0, C_HARDCLOCK)
71#define cv_timedwait_sbt(cvp, lock, sbt, pr, flags) \
72 _cv_timedwait_sbt((cvp), &(lock)->lock_object, (sbt), (pr), (flags))
73#define cv_timedwait_sig(cvp, lock, timo) \
74 _cv_timedwait_sig_sbt((cvp), &(lock)->lock_object, \
75 tick_sbt * (timo), 0, C_HARDCLOCK)
76#define cv_timedwait_sig_sbt(cvp, lock, sbt, pr, flags) \
77 _cv_timedwait_sig_sbt((cvp), &(lock)->lock_object, (sbt), (pr), (flags))
78
79#define cv_broadcast(cvp) cv_broadcastpri(cvp, 0)
80
81#define cv_wmesg(cvp) ((cvp)->cv_description)
82
83#endif /* _KERNEL */
84#endif /* _SYS_CONDVAR_H_ */