.\"	$OpenBSD: clock_getcpuclockid.3,v 1.1 2013/06/17 19:11:54 guenther Exp $
.\"
.\" Copyright (c) 2013 Philip Guenther <guenther@openbsd.org>
.\"
.\" Permission to use, copy, modify, and distribute this software for any
.\" purpose with or without fee is hereby granted, provided that the above
.\" copyright notice and this permission notice appear in all copies.
.\"
.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
.\"
.Dd $Mdocdate: June 17 2013 $
.Dt CLOCK_GETCPUCLOCKID 3
.Os
.Sh NAME
.Nm clock_getcpuclockid
.Nd get a clock measuring process CPU time
.Sh SYNOPSIS
.Fd #include <time.h>
.Ft int
.Fn clock_getcpuclockid "pid_t pid" "clockid_t *clock_id"
.Sh DESCRIPTION
The
.Fn clock_getcpuclockid
function allows the calling process to get a
.Vt clockid_t
value that measures the time spent by CPUs running in user or kernel mode
on behalf of the process specified by
.Fa pid .
If
.Fa pid
is zero, then a clock for the calling process will be returned.
.Sh RETURN VALUES
If successful,
.Fn clock_getcpuclockid
will return zero.
Otherwise an error number will be returned to indicate the error.
.Sh ERRORS
.Fn clock_getcpuclockid
will fail if:
.Bl -tag -width Er
.It Bq Er EPERM
.Fa pid
is neither zero nor the PID of the calling process.
.El
.Sh SEE ALSO
.Xr clock_gettime 2 ,
.Xr pthread_getcpuclockid 3
.Sh STANDARDS
The
.Fn clock_getcpuclockid
function conforms to
.St -p1003.1-2008 .
.Sh HISTORY
The
.Fn clock_getcpuclockid
function first appeared in
.St -p1003.1d-99
and has been available since
.Ox 5.4 .