2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
4 * Copyright (c) 2000 Jake Burkholder <jake@freebsd.org>.
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
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.
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
31 #ifndef _SYS_CONDVAR_H_
32 #define _SYS_CONDVAR_H_
35 #include <sys/queue.h>
40 TAILQ_HEAD(cv_waitq, thread);
43 * Condition variable. The waiters count is protected by the mutex that
44 * protects the condition; that is, the mutex that is passed to cv_wait*()
45 * and is held across calls to cv_signal() and cv_broadcast(). It is an
46 * optimization to avoid looking up the sleep queue if there are no waiters.
49 const char *cv_description;
54 void cv_init(struct cv *cvp, const char *desc);
55 void cv_destroy(struct cv *cvp);
57 void _cv_wait(struct cv *cvp, struct lock_object *lock);
58 void _cv_wait_unlock(struct cv *cvp, struct lock_object *lock);
59 int _cv_wait_sig(struct cv *cvp, struct lock_object *lock);
60 int _cv_timedwait_sbt(struct cv *cvp, struct lock_object *lock,
61 sbintime_t sbt, sbintime_t pr, int flags);
62 int _cv_timedwait_sig_sbt(struct cv *cvp, struct lock_object *lock,
63 sbintime_t sbt, sbintime_t pr, int flags);
65 void cv_signal(struct cv *cvp);
66 void cv_broadcastpri(struct cv *cvp, int pri);
68 #define cv_wait(cvp, lock) \
69 _cv_wait((cvp), &(lock)->lock_object)
70 #define cv_wait_unlock(cvp, lock) \
71 _cv_wait_unlock((cvp), &(lock)->lock_object)
72 #define cv_wait_sig(cvp, lock) \
73 _cv_wait_sig((cvp), &(lock)->lock_object)
74 #define cv_timedwait(cvp, lock, timo) \
75 _cv_timedwait_sbt((cvp), &(lock)->lock_object, \
76 tick_sbt * (timo), 0, C_HARDCLOCK)
77 #define cv_timedwait_sbt(cvp, lock, sbt, pr, flags) \
78 _cv_timedwait_sbt((cvp), &(lock)->lock_object, (sbt), (pr), (flags))
79 #define cv_timedwait_sig(cvp, lock, timo) \
80 _cv_timedwait_sig_sbt((cvp), &(lock)->lock_object, \
81 tick_sbt * (timo), 0, C_HARDCLOCK)
82 #define cv_timedwait_sig_sbt(cvp, lock, sbt, pr, flags) \
83 _cv_timedwait_sig_sbt((cvp), &(lock)->lock_object, (sbt), (pr), (flags))
85 #define cv_broadcast(cvp) cv_broadcastpri(cvp, 0)
87 #define cv_wmesg(cvp) ((cvp)->cv_description)
91 #endif /* _SYS_CONDVAR_H_ */