sys/nanosleep.2

   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
   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 .\"
  36 .\"     @(#)sleep.3     8.1 (Berkeley) 6/4/93
  37 .\"
  38 .Dd April 17, 1997
  39 .Dt NANOSLEEP 2
  40 .Os
  41 .Sh NAME
  42 .Nm nanosleep
  43 .Nd suspend thread execution for an interval measured in nanoseconds
  44 .Sh LIBRARY
  45 .Lb libc
  46 .Sh SYNOPSIS
  47 .In time.h
  48 .Ft int
  49 .Fn nanosleep "const struct timespec *rqtp" "struct timespec *rmtp"
  50 .Sh DESCRIPTION
  51 .Fn Nanosleep
  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
  56 cause it to terminate the sleep early, regardless of the
  57 .Dv SA_RESTART
  58 value on the interrupting signal.
  59 .Sh RETURN VALUES
  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).
  77 .Sh ERRORS
  78 The
  79 .Fn nanosleep
  80 call fails if:
  81 .Bl -tag -width Er
  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.
  92 .It Bq Er EINVAL
  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
 100 .Sh SEE ALSO
 101 .Xr sigsuspend 2 ,
 102 .Xr sleep 3
 103 .Sh STANDARDS
 104 The
 105 .Fn nanosleep
 106 function conforms to
 107 .St -p1003.1b-93 .