1.\" $NetBSD: nanosleep.2,v 1.11 2010/05/17 07:22:03 jruoho Exp $ 2.\" 3.\" Copyright (c) 1986, 1991, 1993 4.\" The Regents of the University of California. All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 3. Neither the name of the University nor the names of its contributors 15.\" may be used to endorse or promote products derived from this software 16.\" without specific prior written permission. 17.\" 18.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 19.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 22.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28.\" SUCH DAMAGE. 29.\" 30.\" @(#)sleep.3 8.1 (Berkeley) 6/4/93 31.\" 32.Dd May 17, 2010 33.Dt NANOSLEEP 2 34.Os 35.Sh NAME 36.Nm nanosleep 37.Nd high resolution sleep 38.Sh LIBRARY 39.Lb libc 40.Sh SYNOPSIS 41.In time.h 42.Ft int 43.Fn nanosleep "const struct timespec *rqtp" "struct timespec *rmtp" 44.Sh DESCRIPTION 45The 46.Fn nanosleep 47suspends execution of the calling process until either the number of 48seconds and nanoseconds specified by 49.Fa rqtp 50have elapsed or a signal is delivered to the calling process and its 51action is to invoke a signal catching function or to terminate the 52process. 53The suspension time may be longer than requested due to the 54scheduling of other activity by the system. 55The 56.Em struct timespec 57is described in 58.Xr timespec 3 . 59.Sh RETURN VALUES 60If the 61.Fn nanosleep 62function returns because the requested time has elapsed, the value 63returned will be zero. 64.Pp 65If the 66.Fn nanosleep 67function returns due to the delivery of a signal, the value returned 68will be the \-1, and the global variable 69.Va errno 70will be set to indicate the interruption. 71If 72.Fa rmtp 73is 74.Pf non- Dv NULL , 75the timespec structure it references is updated to contain the 76unslept amount (the request time minus the time actually slept). 77.Sh ERRORS 78If any of the following conditions occur, the 79.Nm 80function shall return \-1 and set 81.Va errno 82to the corresponding value. 83.Bl -tag -width Er 84.It Bq Er EFAULT 85Either 86.Fa rqtp 87or 88.Fa rmtp 89points to memory that is not a valid part of the process 90address space. 91.It Bq Er EINTR 92.Nm 93was interrupted by the delivery of a signal. 94.It Bq Er EINVAL 95.Fa rqtp 96specified a nanosecond value less than zero or greater than 1000 million. 97.It Bq Er ENOSYS 98.Nm 99is not supported by this implementation. 100.El 101.Sh SEE ALSO 102.Xr sleep 3 , 103.Xr timespec 3 104.Sh STANDARDS 105The 106.Fn nanosleep 107function conforms to 108.St -p1003.1b-93 . 109