1.\" $OpenBSD: nanosleep.2,v 1.1 1997/04/20 20:56:20 tholo 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.\" 4. 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.\" $FreeBSD$ 33.\" 34.Dd April 17, 1997 35.Dt NANOSLEEP 2 36.Os 37.Sh NAME 38.Nm nanosleep 39.Nd suspend process execution for an interval measured in nanoseconds 40.Sh LIBRARY 41.Lb libc 42.Sh SYNOPSIS 43.In time.h 44.Ft int 45.Fn nanosleep "const struct timespec *rqtp" "struct timespec *rmtp" 46.Sh DESCRIPTION 47The 48.Fn nanosleep 49system call 50causes the calling thread to sleep until the time interval specified by 51.Fa rqtp 52has elapsed. 53An unmasked signal will 54cause it to terminate the sleep early, regardless of the 55.Dv SA_RESTART 56value on the interrupting signal. 57.Sh RETURN VALUES 58If the 59.Fn nanosleep 60system call returns because the requested time has elapsed, the value 61returned will be zero. 62.Pp 63If the 64.Fn nanosleep 65system call returns due to the delivery of a signal, the value returned 66will be -1, and the global variable 67.Va errno 68will be set to indicate the interruption. 69If 70.Fa rmtp 71is 72.No non- Ns Dv NULL , 73the timespec structure it references is updated to contain the 74unslept amount (the request time minus the time actually slept). 75.Sh ERRORS 76The 77.Fn nanosleep 78system call fails if: 79.Bl -tag -width Er 80.It Bq Er EFAULT 81Either 82.Fa rqtp 83or 84.Fa rmtp 85points to memory that is not a valid part of the process 86address space. 87.It Bq Er EINTR 88The 89.Fn nanosleep 90system call 91was interrupted by the delivery of a signal. 92.It Bq Er EINVAL 93The 94.Fa rqtp 95argument 96specified a nanosecond value less than zero 97or greater than or equal to 1000 million. 98.It Bq Er ENOSYS 99The 100.Fn nanosleep 101system call 102is not supported by this implementation. 103.El 104.Sh SEE ALSO 105.Xr sigsuspend 2 , 106.Xr sleep 3 107.Sh STANDARDS 108The 109.Fn nanosleep 110system call conforms to 111.St -p1003.1b-93 . 112