xref: /netbsd-src/lib/libc/sys/nanosleep.2 (revision 5e4c038a45edbc7d63b7c2daa76e29f88b64a4e3)
1.\"	$NetBSD: nanosleep.2,v 1.6 2002/02/08 01:28:20 ross Exp $
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34.\"     @(#)sleep.3	8.1 (Berkeley) 6/4/93
35.\"
36.Dd April 17, 1997
37.Dt NANOSLEEP 2
38.Os
39.Sh NAME
40.Nm nanosleep
41.Nd high resolution sleep
42.Sh LIBRARY
43.Lb libc
44.Sh SYNOPSIS
45.Fd #include \*[Lt]time.h\*[Gt]
46.Ft int
47.Fn nanosleep "const struct timespec *rqtp" "struct timespec *rmtp"
48.Sh DESCRIPTION
49The
50.Fn nanosleep
51suspends execution of the calling process until either the number of
52seconds and nanoseconds specified by
53.Fa rqtp
54have elapsed or a signal is delivered to the calling process and its
55action is to invoke a signal catching function or to terminate the
56process.
57The suspension time may be longer than requested due to the
58scheduling of other activity by the system.
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.Sh STANDARDS
104The
105.Fn nanosleep
106function conforms to
107.St -p1003.1b-93 .
108