microtime.9 revision 1.6
$NetBSD: microtime.9,v 1.6 2001/09/04 02:51:16 wiz Exp $
Copyright (c) 1998 The NetBSD Foundation, Inc.
All rights reserved.
This code is derived from software contributed to The NetBSD Foundation
by Jeremy Cooper.
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 the NetBSD
Foundation, Inc. and its contributors.
4. Neither the name of The NetBSD Foundation nor the names of its
contributors may be used to endorse or promote products derived
from this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
.Dd September 14, 1998 .Dt MICROTIME 9 .Os .Sh NAME .Nm microtime .Nd realtime system clock .Sh SYNOPSIS .Fd #include <sys/time.h> .Ft void .Fo "microtime" .Fa "struct timeval *tv" .Fc .Sh DESCRIPTION .Fn microtime returns the current value of the system realtime clock in the structure pointed to by the argument .Fa tv . The system realtime clock is guaranteed to be monotonically increasing at all times. As such, all calls to .Fn microtime are guaranteed to return a system time greater than or equal to the system time returned in any previous calls. .Sh SEE ALSO \" .Xr hz 9 , \" .Xr hardclock 9 , .Xr inittodr 9 , .Xr time 9 , .Xr settimeofday 9 .Sh CODE REFERENCES The implementation of the .Fn microtime function is machine dependent, hence its location in the source code tree varies from architecture to architecture. .Sh BUGS Despite the guarantee that the system realtime clock will always be monotonically increasing, it is always possible for the system clock to be manually reset by the system administrator to any date.
Copyright (c) 1998 The NetBSD Foundation, Inc.
All rights reserved.
This code is derived from software contributed to The NetBSD Foundation
by Jeremy Cooper.
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 the NetBSD
Foundation, Inc. and its contributors.
4. Neither the name of The NetBSD Foundation nor the names of its
contributors may be used to endorse or promote products derived
from this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
.Dd September 14, 1998 .Dt MICROTIME 9 .Os .Sh NAME .Nm microtime .Nd realtime system clock .Sh SYNOPSIS .Fd #include <sys/time.h> .Ft void .Fo "microtime" .Fa "struct timeval *tv" .Fc .Sh DESCRIPTION .Fn microtime returns the current value of the system realtime clock in the structure pointed to by the argument .Fa tv . The system realtime clock is guaranteed to be monotonically increasing at all times. As such, all calls to .Fn microtime are guaranteed to return a system time greater than or equal to the system time returned in any previous calls. .Sh SEE ALSO \" .Xr hz 9 , \" .Xr hardclock 9 , .Xr inittodr 9 , .Xr time 9 , .Xr settimeofday 9 .Sh CODE REFERENCES The implementation of the .Fn microtime function is machine dependent, hence its location in the source code tree varies from architecture to architecture. .Sh BUGS Despite the guarantee that the system realtime clock will always be monotonically increasing, it is always possible for the system clock to be manually reset by the system administrator to any date.