Date: Tue, 4 Jan 2000 14:55:19 -0500 (EST) From: kbyanc@posi.net To: FreeBSD-gnats-submit@freebsd.org Subject: docs/15889: man pages for tvtohz and microtime Message-ID: <200001041955.OAA40696@kronos.alcnet.com>
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>Number: 15889 >Category: docs >Synopsis: man pages for tvtohz and microtime >Confidential: no >Severity: non-critical >Priority: low >Responsible: freebsd-doc >State: open >Quarter: >Keywords: >Date-Required: >Class: change-request >Submitter-Id: current-users >Arrival-Date: Tue Jan 4 12:00:01 PST 2000 >Closed-Date: >Last-Modified: >Originator: Kelly Yancey >Release: FreeBSD 3.2-STABLE i386 >Organization: >Environment: >Description: Documentation for the kernel functions: tvtohz microtime nanotime getmicrotime getnanotime microuptime nanouptime getmicrouptime getnanouptime -Kelly Here are some man pages for review oh, and look, not one but two! Alas, just one poem for you to read But it's so good, that's all you need! :) >How-To-Repeat: >Fix: Attached is a diff taken from /usr/src which includes the 2 man pages the necessary Makefile changes. diff -ruN share/man/man9.orig/Makefile share/man/man9/Makefile --- share/man/man9.orig/Makefile Tue Jan 4 14:30:48 2000 +++ share/man/man9/Makefile Tue Jan 4 14:40:06 2000 @@ -17,7 +17,8 @@ mi_switch.9 namei.9 panic.9 physio.9 posix4.9 ppbconf.9 psignal.9 \ resettodr.9 rtalloc.9 rtentry.9 scsiconf.9 sd.9 sleep.9 spl.9 st.9 \ store.9 style.9 suser.9 time.9 timeout.9 uio.9 \ - vget.9 vnode.9 vput.9 vref.9 vrele.9 vslock.9 + vget.9 vnode.9 vput.9 vref.9 vrele.9 vslock.9 \ + tvtohz.9 microtime.9 MAN9+= device.9 device_add_child.9 device_delete_child.9 device_enable.9 \ device_find_child.9 device_get_devclass.9 device_get_driver.9 \ @@ -77,6 +78,10 @@ MLINKS+=uio.9 uiomove.9 MLINKS+=vref.9 VREF.9 MLINKS+=vslock.9 vsunlock.9 +MLINKS+=microtime.9 microuptime.9 microtime.9 getmicrouptime.9 +MLINKS+=microtime.9 nanouptime.9 microtime.9 getnanouptime.9 +MLINKS+=microtime.9 getmicrotime.9 microtime.9 getnanotime.9 +MLINKS+=microtime.9 nanotime.9 MLINKS+=device_add_child.9 device_add_child_after.9 MLINKS+=device_enable.9 device_disable.9 diff -ruN share/man/man9.orig/microtime.9 share/man/man9/microtime.9 --- share/man/man9.orig/microtime.9 Wed Dec 31 19:00:00 1969 +++ share/man/man9/microtime.9 Tue Jan 4 14:31:20 2000 @@ -0,0 +1,125 @@ +.\" 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. +.\" +.\" $FreeBSD$ +.\" +.Dd January 3, 2000 +.Dt microtime 9 +.Os +.Sh NAME +.Nm microtime , +.Nm getmicrotime , +.Nm nanotime , +.Nm getnanotime +.Nd get the current time +.Pp +.Nm microuptime , +.Nm getmicrouptime , +.Nm nanouptime , +.Nm getnanouptime +.Nd get the time elapsed since boot +.Sh SYNOPSIS +.Fd #include <sys/time.h> +.Ft void +.Fn microtime "struct timeval *tv" +.Ft void +.Fn getmicrotime "struct timeval *tv" +.Ft void +.Fn nanotime "struct timespec *ts" +.Ft void +.Fn getnanotime "struct timespec *tsp" +.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" +.Sh DESCRIPTION +The +.Fn microtime +and +.Fn getmicrotime +functons stores the system time as a +.Ft struct timeval +at the address specified by +.Fa tv . +The +.Fn nanotime +and +.Fn getnanotime +functions perform the same utility, but record the time as a +.Ft struct timespec +instead. +.Pp +.Fn Microtime +and +.Fn nanotime +always query the timecounter to return the current time as precisely as +possible. Whereas +.Fn getmicrotime +and +.Fn getnanotime +functions are abstractions which can alternately return a less precise, but +faster to obtain, time. This behaviour can be toggled via the +kern.timecounter.method sysctl variable: +.Bl -tag -width ABC +.It Dv 0 +sacrifice precision in favor of faster code execution +.It Dv 1 +return the more precise time (the same as calling +.Fn microtime +or +.Fn nanotime +). +.El +.Pp +The "uptime" variants of these functions return the time since system boot rather +than absolute time, but are otherwise identical. These are well suited for time +interval measurements. +.Pp +The intent of the +.Fn getmicrotime , +.Fn getnanotime , +.Fn getmicrouptime , +and +.Fn getnanouptime +functions is to enforce the user's preference for timer accuracy versus execution time. +.Sh SEE ALSO +.Xr tvtohz 9 +.Sh DIAGNOSTICS +Buggy hardware can cause "calcru negative..." when kern.timecounter.method is set to 0. +.Sh HISTORY +The +.Nm microtime +and +.Nm nanotime +functions first appeared in +.Fx 3.0 +but existed in other incarnations since +.Bx 4.4 +.Sh AUTHORS +This manual page was written by +.An Kelly Yancey Aq kbyanc@posi.net . diff -ruN share/man/man9.orig/tvtohz.9 share/man/man9/tvtohz.9 --- share/man/man9.orig/tvtohz.9 Wed Dec 31 19:00:00 1969 +++ share/man/man9/tvtohz.9 Tue Jan 4 14:31:15 2000 @@ -0,0 +1,57 @@ +.\" 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. +.\" +.\" $FreeBSD$ +.\" +.Dd January 3, 2000 +.Dt tvtohz 9 +.Os +.Sh NAME +.Nm tvtohz +.Nd compute number of ticks in the specified amount of time +.Sh SYNOPSIS +.Fd #include <sys/time.h> +.Ft int +.Fn tvtohz "struct timeval *tv" +.Sh DESCRIPTION +The +.Fn tvtohz +function accepts a single argument +.Fa tv +which specifies the time interval over which to calculate the number +of system ticks that would elapse. +.Sh RETURN VALUES +Returns the integral number of system ticks expected to elapse in the given +interval, including the current tick. +.Sh SEE ALSO +.Xr microtime 9 , +.Xr timeout 9 +.Sh HISTORY +The +.Nm +function first appeared in +.Fx 3.0 +.Sh AUTHORS +This manual page was written by +.An Kelly Yancey Aq kbyanc@posi.net . >Release-Note: >Audit-Trail: >Unformatted: To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-doc" in the body of the message
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