From owner-freebsd-hackers  Mon Dec 22 00:50:34 1997
Return-Path: <owner-freebsd-hackers>
Received: (from root@localhost)
          by hub.freebsd.org (8.8.7/8.8.7) id AAA09382
          for hackers-outgoing; Mon, 22 Dec 1997 00:50:34 -0800 (PST)
          (envelope-from owner-freebsd-hackers)
Received: from word.smith.net.au (vh1.gsoft.com.au [203.38.152.122])
          by hub.freebsd.org (8.8.7/8.8.7) with ESMTP id AAA09373
          for <hackers@FreeBSD.ORG>; Mon, 22 Dec 1997 00:50:27 -0800 (PST)
          (envelope-from mike@word.smith.net.au)
Received: from word (localhost [127.0.0.1])
	by word.smith.net.au (8.8.8/8.8.5) with ESMTP id TAA00494;
	Mon, 22 Dec 1997 19:14:48 +1030 (CST)
Message-Id: <199712220844.TAA00494@word.smith.net.au>
X-Mailer: exmh version 2.0zeta 7/24/97
To: "J. Weatherbee - Senior Systems Architect" <jamil@acroal.com>
cc: hackers@FreeBSD.ORG
Subject: Re: Am I off my rocker? (/dev/tick device) 
In-reply-to: Your message of "Mon, 22 Dec 1997 00:08:48 -0800."
             <Pine.BSF.3.96.971221234402.2497A-100000@acroal.com> 
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Date: Mon, 22 Dec 1997 19:14:48 +1030
From: Mike Smith <mike@smith.net.au>
Sender: owner-freebsd-hackers@FreeBSD.ORG
X-Loop: FreeBSD.org
Precedence: bulk

> for read.  I may be dealing with 64 or so descriptors, but I thought it
> might be useful to have a /dev/tick pseudo device that would come ready
> for i/o say 10-100 times a second (depending on an ioctl).  So suppose you
> open this device, and ioctl() it to 10 hertz, if you went into select() it
> would return ~100ms after opening the read ready on the /dev/tick fd. When
> you call read on /dev/tick, you get a unsigned int representing the number
> of microseconds (or alternately milliseconds) elapsed since the descriptor
> was opened.

Try 'man setitimer' and 'man gettimeofday'.  There's nothing you're 
suggesting that can't already be done with those two.

mike