1997-03-22 19:09:31 +00:00
|
|
|
.\" $NetBSD: time.9,v 1.1 1995/11/25 21:24:53 perry Exp $
|
|
|
|
.\"
|
|
|
|
.\" Copyright (c) 1994 Christopher G. Demetriou
|
|
|
|
.\" 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.
|
|
|
|
.\" 3. All advertising materials mentioning features or use of this software
|
|
|
|
.\" must display the following acknowledgement:
|
|
|
|
.\" This product includes software developed by Christopher G. Demetriou
|
|
|
|
.\" for the NetBSD Project.
|
|
|
|
.\" 3. The name of the author may not be used to endorse or promote products
|
|
|
|
.\" derived from this software without specific prior written permission
|
|
|
|
.\"
|
|
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 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.
|
|
|
|
.\"
|
1999-08-28 00:22:10 +00:00
|
|
|
.\" $FreeBSD$
|
1999-07-12 21:02:10 +00:00
|
|
|
.\"
|
2004-09-17 07:24:18 +00:00
|
|
|
.Dd September 17, 2004
|
1997-03-22 19:09:31 +00:00
|
|
|
.Dt TIME 9
|
2001-07-10 15:31:11 +00:00
|
|
|
.Os
|
1997-03-22 19:09:31 +00:00
|
|
|
.Sh NAME
|
|
|
|
.Nm boottime ,
|
2004-09-17 07:24:18 +00:00
|
|
|
.Nm time_second ,
|
|
|
|
.Nm time_uptime
|
1997-03-22 19:09:31 +00:00
|
|
|
.Nd system time variables
|
|
|
|
.Sh SYNOPSIS
|
2005-01-12 21:48:25 +00:00
|
|
|
.In sys/time.h
|
|
|
|
.Pp
|
|
|
|
.Vt extern struct timeval boottime ;
|
2006-03-02 19:47:41 +00:00
|
|
|
.Vt extern time_t time_second ;
|
|
|
|
.Vt extern time_t time_uptime ;
|
1997-03-22 19:09:31 +00:00
|
|
|
.Sh DESCRIPTION
|
|
|
|
The
|
|
|
|
.Va boottime
|
2003-10-23 02:33:03 +00:00
|
|
|
variable holds the system boot time.
|
1997-03-22 19:09:31 +00:00
|
|
|
.Pp
|
|
|
|
The
|
2004-09-17 07:24:18 +00:00
|
|
|
.Va time_second
|
|
|
|
variable is the system's
|
|
|
|
.Dq wall time
|
|
|
|
clock to the second.
|
1997-03-22 19:09:31 +00:00
|
|
|
.Pp
|
|
|
|
The
|
2005-01-12 21:48:25 +00:00
|
|
|
.Va time_uptime
|
|
|
|
variable is the number of seconds since boot.
|
1997-03-22 19:09:31 +00:00
|
|
|
.Pp
|
|
|
|
The
|
2005-01-21 20:48:00 +00:00
|
|
|
.Xr bintime 9 ,
|
2004-09-17 07:24:18 +00:00
|
|
|
.Xr getbintime 9 ,
|
|
|
|
.Xr microtime 9 ,
|
|
|
|
.Xr getmicrotime 9 ,
|
|
|
|
.Xr nanotime 9 ,
|
|
|
|
and
|
2005-01-12 21:48:25 +00:00
|
|
|
.Xr getnanotime 9
|
2004-09-17 07:24:18 +00:00
|
|
|
functions can be used to get the current time more accurately and in an
|
|
|
|
atomic manner.
|
|
|
|
Similarly, the
|
2005-01-21 20:48:00 +00:00
|
|
|
.Xr binuptime 9 ,
|
2004-09-17 07:24:18 +00:00
|
|
|
.Xr getbinuptime 9 ,
|
|
|
|
.Xr microuptime 9 ,
|
|
|
|
.Xr getmicrouptime 9 ,
|
|
|
|
.Xr nanouptime 9 ,
|
1997-03-22 19:09:31 +00:00
|
|
|
and
|
2005-01-12 21:48:25 +00:00
|
|
|
.Xr getnanouptime 9
|
2004-09-17 07:24:18 +00:00
|
|
|
functions can be used to get the time elapse since boot more accurately
|
|
|
|
and in an atomic manner.
|
|
|
|
The
|
|
|
|
.Va boottime
|
|
|
|
variable may be read and written without special precautions.
|
1997-03-22 19:09:31 +00:00
|
|
|
.Sh SEE ALSO
|
2004-09-17 07:24:18 +00:00
|
|
|
.Xr clock_settime 2 ,
|
|
|
|
.Xr ntp_adjtime 2 ,
|
1997-03-22 19:09:31 +00:00
|
|
|
.Xr settimeofday 2 ,
|
2005-06-15 13:31:23 +00:00
|
|
|
.Xr bintime 9 ,
|
|
|
|
.Xr binuptime 9 ,
|
2004-09-17 07:24:18 +00:00
|
|
|
.Xr getbintime 9 ,
|
|
|
|
.Xr getbinuptime 9 ,
|
|
|
|
.Xr getmicrotime 9 ,
|
|
|
|
.Xr getmicrouptime 9 ,
|
|
|
|
.Xr getnanotime 9 ,
|
|
|
|
.Xr getnanouptime 9 ,
|
|
|
|
.Xr microtime 9 ,
|
|
|
|
.Xr microuptime 9 ,
|
2005-01-21 20:48:00 +00:00
|
|
|
.Xr nanotime 9 ,
|
2004-09-17 07:24:18 +00:00
|
|
|
.Xr nanouptime 9
|
|
|
|
.Rs
|
|
|
|
.%A "Poul-Henning Kamp"
|
|
|
|
.%T "Timecounters: Efficient and precise timekeeping in SMP kernels"
|
2005-01-12 21:48:25 +00:00
|
|
|
.%J "Proceedings of EuroBSDCon 2002, Amsterdam"
|
2004-09-17 07:24:18 +00:00
|
|
|
.%O /usr/share/doc/papers/timecounter.ascii.gz
|
|
|
|
.Re
|
|
|
|
.Rs
|
|
|
|
.%A "Marshall Kirk McKusick"
|
|
|
|
.%A "George V. Neville-Neil"
|
|
|
|
.%B "The Design and Implementation of the FreeBSD Operating System"
|
|
|
|
.%D "July 2004"
|
|
|
|
.%I "Addison-Wesley"
|
|
|
|
.%P "57-61,65-66"
|
|
|
|
.Re
|