.\" Copyright (c) 2000 Kelly Yancey
.\" All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\" $FreeBSD: head/share/man/man9/microuptime.9 279115 2015-02-21 22:25:24Z jmg $
.\"
.Dd February 21, 2015
.Dt MICROUPTIME 9
.Os
.Sh NAME
.Nm binuptime ,
.Nm getbinuptime ,
.Nm microuptime ,
.Nm getmicrouptime ,
.Nm nanouptime ,
.Nm getnanouptime ,
.Nm sbinuptime ,
.Nm getsbinuptime
.Nd get the time elapsed since boot
.Sh SYNOPSIS
.In sys/time.h
.Ft void
.Fn binuptime "struct bintime *bt"
.Ft void
.Fn getbinuptime "struct bintime *bt"
.Ft void
.Fn microuptime "struct timeval *tv"
.Ft void
.Fn getmicrouptime "struct timeval *tv"
.Ft void
.Fn nanouptime "struct timespec *ts"
.Ft void
.Fn getnanouptime "struct timespec *tsp"
.Ft sbintime_t
.Fn sbinuptime "void"
.Ft sbintime_t
.Fn getsbinuptime "void"
.Sh DESCRIPTION
The
.Fn binuptime
and
.Fn getbinuptime
functions store the time elapsed since boot as a
.Vt "struct bintime"
at the address specified by
.Fa bt .
The
.Fn microuptime
and
.Fn getmicrouptime
functions perform the same utility, but record the elapsed time as a
.Vt "struct timeval"
instead.
Similarly the
.Fn nanouptime
and
.Fn getnanouptime
functions store the elapsed time as a
.Vt "struct timespec" .
The
.Fn sbinuptime
and
.Fn getsbinuptime
functions return the time elapsed since boot as a
.Vt "sbintime_t" .
.Pp
The
.Fn binuptime ,
.Fn microuptime ,
.Fn nanouptime ,
and
.Fn sbinuptime
functions
always query the timecounter to return the current time as precisely as
possible.
Whereas
.Fn getbinuptime ,
.Fn getmicrouptime ,
.Fn getnanouptime ,
and
.Fn getsbinuptime
functions are abstractions which return a less precise, but
faster to obtain, time.
.Pp
The intent of the
.Fn getbinuptime ,
.Fn getmicrouptime ,
.Fn getnanouptime ,
and
.Fn getsbinuptime
functions is to enforce the user's preference for timer accuracy versus
execution time.
.Sh SEE ALSO
.Xr bintime 9 ,
.Xr get_cyclecount 9 ,
.Xr getbintime 9 ,
.Xr getmicrotime 9 ,
.Xr getnanotime 9 ,
.Xr microtime 9 ,
.Xr nanotime 9 ,
.Xr tvtohz 9
.Sh AUTHORS
This manual page was written by
.An Kelly Yancey Aq Mt kbyanc@posi.net .