[apple/libc.git] / sys / nanosleep.2

.\" $FreeBSD: src/lib/libc/sys/nanosleep.2,v 1.8.2.4 2001/12/14 18:34:01 ru Exp $
.\"	$OpenBSD: nanosleep.2,v 1.1 1997/04/20 20:56:20 tholo Exp $
.\"	$NetBSD: nanosleep.2,v 1.1 1997/04/17 18:12:02 jtc Exp $
.\"
.\" Copyright (c) 1986, 1991, 1993
.\"	The Regents of the University of California.  All rights reserved.
.\"
.\" 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 University of
.\"	California, Berkeley and its contributors.
.\" 4. Neither the name of the University 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 REGENTS 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 REGENTS 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.
.\"
.\"     @(#)sleep.3	8.1 (Berkeley) 6/4/93
.\"
.Dd April 17, 1997
.Dt NANOSLEEP 2
.Os
.Sh NAME
.Nm nanosleep
.Nd suspend thread execution for an interval measured in nanoseconds
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In time.h
.Ft int
.Fn nanosleep "const struct timespec *rqtp" "struct timespec *rmtp"
.Sh DESCRIPTION
.Fn Nanosleep
causes the calling thread to sleep for the specified time
(the actual time slept may be longer, due to system latencies
and possible limitations in the timer resolution of the hardware).
An unmasked signal will
cause it to terminate the sleep early, regardless of the
.Dv SA_RESTART
value on the interrupting signal.
.Sh RETURN VALUES
If the
.Fn nanosleep
function returns because the requested time has elapsed, the value
returned will be zero.
.Pp
If the
.Fn nanosleep
function returns due to the delivery of a signal, the value returned
will be the -1, and the global variable
.Va errno
will be set to indicate the interruption.
If
.Fa rmtp
is
.Pf non- Dv NULL ,
the timespec structure it references is updated to contain the
unslept amount (the request time minus the time actually slept).
.Sh ERRORS
The
.Fn nanosleep
call fails if:
.Bl -tag -width Er
.It Bq Er EFAULT
Either
.Fa rqtp
or
.Fa rmtp
points to memory that is not a valid part of the process
address space.
.It Bq Er EINTR
.Fn nanosleep
was interrupted by the delivery of a signal.
.It Bq Er EINVAL
.Fa rqtp
specified a nanosecond value less than zero
or greater than or equal to 1000 million.
.It Bq Er ENOSYS
.Fn nanosleep
is not supported by this implementation.
.El
.Sh SEE ALSO
.Xr sigsuspend 2 ,
.Xr sleep 3
.Sh STANDARDS
The
.Fn nanosleep
function conforms to
.St -p1003.1b-93 .
Commit	Line	Data
5b2abdfb A	1	.\" $FreeBSD: src/lib/libc/sys/nanosleep.2,v 1.8.2.4 2001/12/14 18:34:01 ru Exp $
	2	.\" $OpenBSD: nanosleep.2,v 1.1 1997/04/20 20:56:20 tholo Exp $
	3	.\" $NetBSD: nanosleep.2,v 1.1 1997/04/17 18:12:02 jtc Exp $
	4	.\"
	5	.\" Copyright (c) 1986, 1991, 1993
e9ce8d39 A	6	.\" The Regents of the University of California. All rights reserved.
	7	.\"
	8	.\" Redistribution and use in source and binary forms, with or without
	9	.\" modification, are permitted provided that the following conditions
	10	.\" are met:
	11	.\" 1. Redistributions of source code must retain the above copyright
	12	.\" notice, this list of conditions and the following disclaimer.
	13	.\" 2. Redistributions in binary form must reproduce the above copyright
	14	.\" notice, this list of conditions and the following disclaimer in the
	15	.\" documentation and/or other materials provided with the distribution.
	16	.\" 3. All advertising materials mentioning features or use of this software
	17	.\" must display the following acknowledgement:
	18	.\" This product includes software developed by the University of
	19	.\" California, Berkeley and its contributors.
	20	.\" 4. Neither the name of the University nor the names of its contributors
	21	.\" may be used to endorse or promote products derived from this software
	22	.\" without specific prior written permission.
	23	.\"
	24	.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	25	.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	26	.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	27	.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	28	.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	29	.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	30	.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	31	.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	32	.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	33	.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	34	.\" SUCH DAMAGE.
	35	.\"
5b2abdfb	36	.\" @(#)sleep.3 8.1 (Berkeley) 6/4/93
e9ce8d39	37	.\"
5b2abdfb A	38	.Dd April 17, 1997
5b2abdfb A	39	.Dt NANOSLEEP 2
e9ce8d39 A	40	.Os
e9ce8d39 A	41	.Sh NAME
5b2abdfb	42	.Nm nanosleep
59e0d9fe	43	.Nd suspend thread execution for an interval measured in nanoseconds
e9ce8d39 A	44	.Sh LIBRARY
	45	.Lb libc
	46	.Sh SYNOPSIS
5b2abdfb	47	.In time.h
e9ce8d39	48	.Ft int
5b2abdfb	49	.Fn nanosleep "const struct timespec rqtp" "struct timespec rmtp"
e9ce8d39	50	.Sh DESCRIPTION
5b2abdfb	51	.Fn Nanosleep
59e0d9fe A	52	causes the calling thread to sleep for the specified time
	53	(the actual time slept may be longer, due to system latencies
	54	and possible limitations in the timer resolution of the hardware).
	55	An unmasked signal will
5b2abdfb A	56	cause it to terminate the sleep early, regardless of the
	57	.Dv SA_RESTART
	58	value on the interrupting signal.
e9ce8d39	59	.Sh RETURN VALUES
5b2abdfb A	60	If the
	61	.Fn nanosleep
	62	function returns because the requested time has elapsed, the value
	63	returned will be zero.
	64	.Pp
	65	If the
	66	.Fn nanosleep
	67	function returns due to the delivery of a signal, the value returned
	68	will be the -1, and the global variable
	69	.Va errno
	70	will be set to indicate the interruption.
	71	If
	72	.Fa rmtp
	73	is
	74	.Pf non- Dv NULL ,
	75	the timespec structure it references is updated to contain the
	76	unslept amount (the request time minus the time actually slept).
e9ce8d39	77	.Sh ERRORS
5b2abdfb A	78	The
	79	.Fn nanosleep
	80	call fails if:
e9ce8d39	81	.Bl -tag -width Er
5b2abdfb A	82	.It Bq Er EFAULT
	83	Either
	84	.Fa rqtp
	85	or
	86	.Fa rmtp
	87	points to memory that is not a valid part of the process
	88	address space.
	89	.It Bq Er EINTR
	90	.Fn nanosleep
	91	was interrupted by the delivery of a signal.
e9ce8d39	92	.It Bq Er EINVAL
5b2abdfb A	93	.Fa rqtp
	94	specified a nanosecond value less than zero
	95	or greater than or equal to 1000 million.
	96	.It Bq Er ENOSYS
	97	.Fn nanosleep
	98	is not supported by this implementation.
	99	.El
e9ce8d39	100	.Sh SEE ALSO
5b2abdfb A	101	.Xr sigsuspend 2 ,
	102	.Xr sleep 3
	103	.Sh STANDARDS
e9ce8d39	104	The
5b2abdfb A	105	.Fn nanosleep
	106	function conforms to
	107	.St -p1003.1b-93 .