FreeBSD/Linux Kernel Cross Reference
sys/sys/condvar.h
1 /* $NetBSD: condvar.h,v 1.10 2008/05/31 13:36:25 ad Exp $ */
2
3 /*-
4 * Copyright (c) 2006, 2007, 2008 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Andrew Doran.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32 #ifndef _SYS_CONDVAR_H_
33 #define _SYS_CONDVAR_H_
34
35 #include <sys/mutex.h>
36
37 /*
38 * The condition variable implementation is private to kern_condvar.c but
39 * the size of a kcondvar_t must remain constant. cv_opaque is protected
40 * both by the interlock passed to cv_wait() (enqueue only), and the sleep
41 * queue lock acquired with sleeptab_lookup() (enqueue and dequeue).
42 * cv_wmesg is static and does not change throughout the life of the CV.
43 */
44 typedef struct kcondvar {
45 void *cv_opaque[2]; /* sleep queue */
46 const char *cv_wmesg; /* description for /bin/ps */
47 } kcondvar_t;
48
49 #ifdef _KERNEL
50
51 void cv_init(kcondvar_t *, const char *);
52 void cv_destroy(kcondvar_t *);
53
54 void cv_wait(kcondvar_t *, kmutex_t *);
55 int cv_wait_sig(kcondvar_t *, kmutex_t *);
56 int cv_timedwait(kcondvar_t *, kmutex_t *, int);
57 int cv_timedwait_sig(kcondvar_t *, kmutex_t *, int);
58
59 void cv_signal(kcondvar_t *);
60 void cv_broadcast(kcondvar_t *);
61
62 void cv_wakeup(kcondvar_t *);
63
64 bool cv_has_waiters(kcondvar_t *);
65 bool cv_is_valid(kcondvar_t *);
66
67 /* The "lightning bolt", awoken once per second by the clock interrupt. */
68 extern kcondvar_t lbolt;
69
70 #endif /* _KERNEL */
71
72 #endif /* _SYS_CONDVAR_H_ */
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