FreeBSD/Linux Kernel Cross Reference
sys/sys/condvar.h
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: src/sys/sys/condvar.h,v 1.15 2008/03/12 06:31:06 jeff Exp $
27 */
28
29 #ifndef _SYS_CONDVAR_H_
30 #define _SYS_CONDVAR_H_
31
32 #ifndef LOCORE
33 #include <sys/queue.h>
34
35 struct lock_object;
36 struct thread;
37
38 TAILQ_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 */
46 struct cv {
47 const char *cv_description;
48 int cv_waiters;
49 };
50
51 #ifdef _KERNEL
52 void cv_init(struct cv *cvp, const char *desc);
53 void cv_destroy(struct cv *cvp);
54
55 void _cv_wait(struct cv *cvp, struct lock_object *lock);
56 void _cv_wait_unlock(struct cv *cvp, struct lock_object *lock);
57 int _cv_wait_sig(struct cv *cvp, struct lock_object *lock);
58 int _cv_timedwait(struct cv *cvp, struct lock_object *lock, int timo);
59 int _cv_timedwait_sig(struct cv *cvp, struct lock_object *lock, int timo);
60
61 void cv_signal(struct cv *cvp);
62 void cv_broadcastpri(struct cv *cvp, int pri);
63
64 #define cv_wait(cvp, lock) \
65 _cv_wait((cvp), &(lock)->lock_object)
66 #define cv_wait_unlock(cvp, lock) \
67 _cv_wait_unlock((cvp), &(lock)->lock_object)
68 #define cv_wait_sig(cvp, lock) \
69 _cv_wait_sig((cvp), &(lock)->lock_object)
70 #define cv_timedwait(cvp, lock, timo) \
71 _cv_timedwait((cvp), &(lock)->lock_object, (timo))
72 #define cv_timedwait_sig(cvp, lock, timo) \
73 _cv_timedwait_sig((cvp), &(lock)->lock_object, (timo))
74
75 #define cv_broadcast(cvp) cv_broadcastpri(cvp, 0)
76
77 #define cv_wmesg(cvp) ((cvp)->cv_description)
78
79 #endif /* _KERNEL */
80 #endif /* !LOCORE */
81 #endif /* _SYS_CONDVAR_H_ */
82
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