1.\" $OpenBSD: nanosleep.2,v 1.15 2015/05/31 23:54:25 schwarze Exp $ 2.\" $NetBSD: nanosleep.2,v 1.1 1997/04/17 18:12:02 jtc Exp $ 3.\" 4.\" Copyright (c) 1986, 1991, 1993 5.\" The Regents of the University of California. All rights reserved. 6.\" 7.\" Redistribution and use in source and binary forms, with or without 8.\" modification, are permitted provided that the following conditions 9.\" are met: 10.\" 1. Redistributions of source code must retain the above copyright 11.\" notice, this list of conditions and the following disclaimer. 12.\" 2. Redistributions in binary form must reproduce the above copyright 13.\" notice, this list of conditions and the following disclaimer in the 14.\" documentation and/or other materials provided with the distribution. 15.\" 3. Neither the name of the University nor the names of its contributors 16.\" may be used to endorse or promote products derived from this software 17.\" without specific prior written permission. 18.\" 19.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29.\" SUCH DAMAGE. 30.\" 31.\" @(#)sleep.3 8.1 (Berkeley) 6/4/93 32.\" 33.Dd $Mdocdate: May 31 2015 $ 34.Dt NANOSLEEP 2 35.Os 36.Sh NAME 37.Nm nanosleep 38.Nd high resolution sleep 39.Sh SYNOPSIS 40.In time.h 41.Ft int 42.Fn nanosleep "const struct timespec *timeout" "struct timespec *remainder" 43.Sh DESCRIPTION 44.Fn nanosleep 45suspends execution of the calling process for the duration specified by 46.Fa timeout . 47An unmasked signal will cause it to terminate the sleep early, 48regardless of the 49.Dv SA_RESTART 50value on the interrupting signal. 51.Sh RETURN VALUES 52If the 53.Fn nanosleep 54function returns because the requested duration has elapsed, the value 55returned will be zero. 56.Pp 57If the 58.Fn nanosleep 59function returns due to the delivery of a signal, the value returned 60will be \-1, and the global variable 61.Va errno 62will be set to indicate the interruption. 63If 64.Fa remainder 65is non-null, the timespec structure it references is updated to contain the 66unslept amount (the requested duration minus the duration actually slept). 67.Sh ERRORS 68If any of the following conditions occur, the 69.Fn nanosleep 70function shall return \-1 and set 71.Va errno 72to the corresponding value. 73.Bl -tag -width Er 74.It Bq Er EINTR 75.Fn nanosleep 76was interrupted by the delivery of a signal. 77.It Bq Er EINVAL 78.Fa timeout 79specified a nanosecond value less than zero or greater than 1000 million, 80or a second value less than zero or greater than 100 million. 81.It Bq Er EFAULT 82Either 83.Fa timeout 84or 85.Fa remainder 86points to memory that is not a valid part of the process address space. 87.El 88.Sh SEE ALSO 89.Xr sleep 1 , 90.Xr sleep 3 91.Sh STANDARDS 92The 93.Fn nanosleep 94function conforms to 95.St -p1003.1-2008 . 96.Sh HISTORY 97The predecessor of this system call, 98.Fn sleep , 99appeared in 100.At v3 , 101but was removed when 102.Xr alarm 3 103was introduced into 104.At v7 . 105The 106.Fn nanosleep 107system call has been available since 108.Nx 1.3 109and was ported to 110.Ox 2.1 111and 112.Fx 3.0 . 113