git.saurik.com Git - apple/libc.git/blame

Commit	Line	Data
5b2abdfb	1	.\" Copyright (c) 1986, 1991, 1993
e9ce8d39 A	2	.\" The Regents of the University of California. All rights reserved.
	3	.\"
	4	.\" Redistribution and use in source and binary forms, with or without
	5	.\" modification, are permitted provided that the following conditions
	6	.\" are met:
	7	.\" 1. Redistributions of source code must retain the above copyright
	8	.\" notice, this list of conditions and the following disclaimer.
	9	.\" 2. Redistributions in binary form must reproduce the above copyright
	10	.\" notice, this list of conditions and the following disclaimer in the
	11	.\" documentation and/or other materials provided with the distribution.
e9ce8d39 A	12	.\" 4. Neither the name of the University nor the names of its contributors
	13	.\" may be used to endorse or promote products derived from this software
	14	.\" without specific prior written permission.
	15	.\"
	16	.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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	.\"
5b2abdfb	28	.\" @(#)sleep.3 8.1 (Berkeley) 6/4/93
1f2f436a	29	.\" $FreeBSD: src/lib/libc/gen/sleep.3,v 1.17 2007/01/09 00:27:55 imp Exp $
e9ce8d39	30	.\"
5b2abdfb A	31	.Dd February 13, 1998
5b2abdfb A	32	.Dt SLEEP 3
e9ce8d39 A	33	.Os
e9ce8d39 A	34	.Sh NAME
5b2abdfb	35	.Nm sleep
ad3c9f2a	36	.Nd suspend thread execution for an interval measured in seconds
e9ce8d39 A	37	.Sh LIBRARY
	38	.Lb libc
	39	.Sh SYNOPSIS
5b2abdfb A	40	.In unistd.h
	41	.Ft unsigned int
	42	.Fn sleep "unsigned int seconds"
e9ce8d39 A	43	.Sh DESCRIPTION
e9ce8d39 A	44	The
5b2abdfb	45	.Fn sleep
ad3c9f2a	46	function suspends execution of the calling thread until either
5b2abdfb	47	.Fa seconds
ad3c9f2a	48	seconds have elapsed or a signal is delivered to the thread and its
5b2abdfb	49	action is to invoke a signal-catching function or to terminate the
ad3c9f2a	50	thread or process.
5b2abdfb A	51	System activity may lengthen the sleep by an indeterminate amount.
	52	.Pp
	53	This function is implemented using
	54	.Xr nanosleep 2
	55	by pausing for
	56	.Fa seconds
	57	seconds or until a signal occurs.
	58	Consequently, in this implementation,
	59	sleeping has no effect on the state of process timers,
	60	and there is no special handling for SIGALRM.
e9ce8d39	61	.Sh RETURN VALUES
5b2abdfb A	62	If the
	63	.Fn sleep
	64	function returns because the requested time has elapsed, the value
3d9156a7 A	65	returned will be zero.
3d9156a7 A	66	If the
5b2abdfb A	67	.Fn sleep
	68	function returns due to the delivery of a signal, the value returned
	69	will be the unslept amount (the requested time minus the time actually
	70	slept) in seconds.
e9ce8d39	71	.Sh SEE ALSO
5b2abdfb A	72	.Xr nanosleep 2 ,
	73	.Xr usleep 3
	74	.Sh STANDARDS
e9ce8d39	75	The
5b2abdfb A	76	.Fn sleep
	77	function conforms to
	78	.St -p1003.1-90 .
	79	.Sh HISTORY
	80	A
	81	.Fn sleep
	82	function appeared in
	83	.At v7 .