1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
|
.\" $NetBSD: timeout.9,v 1.7 1999/03/16 00:40:48 garbled Exp $
.\"
.\" Copyright (c) 1996 The NetBSD Foundation, Inc.
.\" All rights reserved.
.\"
.\" This code is derived from software contributed to The NetBSD Foundation
.\" by Paul Kranenburg.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\" notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\" notice, this list of conditions and the following disclaimer in the
.\" documentation and/or other materials provided with the distribution.
.\" 3. All advertising materials mentioning features or use of this software
.\" must display the following acknowledgement:
.\" This product includes software developed by the NetBSD
.\" Foundation, Inc. and its contributors.
.\" 4. Neither the name of The NetBSD Foundation nor the names of its
.\" contributors may be used to endorse or promote products derived
.\" from this software without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
.\" POSSIBILITY OF SUCH DAMAGE.
.\"
.Dd June 23, 1996
.Dt TIMEOUT 9
.Os
.Sh NAME
.Nm timeout ,
.Nm untimeout
.Nd execute a function after a specified length of time
.Sh SYNOPSIS
.Fd #include <sys/types.h>
.Fd #include <sys/systm.h>
.Ft void
.Fn "timeout" "void (*ftn)(void *)" "void *arg" "int ticks"
.Ft void
.Fn "untimeout" "void (*ftn)(void *)" "void *arg"
.Sh DESCRIPTION
The function
.Fn timeout
schedules a call to the function given by the argument
.Fa ftn
to take place after
.Fa ticks Ns No /hz
seconds.
Non-positive values of
.Fa ticks
are silently converted to the value
.Sq 1 .
.Fa ftn
should be a pointer to a function that takes a
.Fa void *
argument, to which the argument
.Fa arg
will be passed.
.Pp
The function
.Fn untimeout
cancels the first scheduled call
.Pq i.e. the one with the shortest delay left
that matches the
.Aq Fa ftn , Ns Fa arg
pair.
If a match can not be found in the callout queue, nothing happens.
.Pp
The callout queue is statically sized, dependent on the
.Va MAXUSERS
parameter.
.Sh CODE REFERENCES
These functions are implemented in the file
.Pa sys/kern/kern_clock.c .
.Sh SEE ALSO
.Xr hz 9 ,
.Xr sleep 9
.Sh BUGS
.Fn untimeout
should probably remove all matches from the queue.
|
