From: cis.ohio-state.edu!zaphod.mps.ohio-state.edu!cs.utexas.edu!wupost!spool.m u.edu!umn.edu!hecto.cs.umn.edu!hansen@ucbvax.Berkeley.EDU (David M. Hansen)
Subject: Re: What is "real-time"?
Date: 18 Oct 92 20:31:43 GMT [thread overview]
Message-ID: <1992Oct18.203143.182@news2.cis.umn.edu> (raw)
In article <gsc.719318183@coombs>, gsc@coombs.anu.edu.au (Sean Case) writes:
|> hansen@micro.cs.umn.edu (David M. Hansen) writes:
|>
|> >A better definition, I think (this is not original BTW), is that a
|> >real-time system must _manage_ time as a resource.
|>
|> This is the definition I've been working towards for some time.
|> Do you have a reference for it?
Unfortunately, no, I don't. To be honest, at the time I read this, I
didn't much like it, although it did stick in my mind. I believe I read it
in Computer Language magazine about three years ago, and I believe it was
P. J. Plauger who wrote it, but I'm far from certain on either count.
|>
|> >Certainly, it must meet all its deadlines (I imagine that word has
|> >an interesting etymology), but also it must delay taking action on
|> >a calculation if that calculation completes before its answer is
|> >required.
|>
|> More generally, it must perform calculations taking into account the
|> time elapsed since its inputs were valid and the time that will elapse
|> before its outputs are used.
|>
|> Consider a radar tracking system: it has a position for an object at
|> some point in the past, and must calculate where to look for it the
|> next time around.
Well put, I agree completely.
-=Dave
next reply other threads:[~1992-10-18 20:31 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
1992-10-18 20:31 cis.ohio-state.edu!zaphod.mps.ohio-state.edu!cs.utexas.edu!wupost!spool.m [this message]
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1992-10-22 15:38 What is "real-time"? dog.ee.lbl.gov!hellgate.utah.edu!cs.utexas.edu!csc.ti.com!tilde.csc.ti.co
1992-10-21 18:34 Al Mok
1992-10-21 3:58 munnari.oz.au!metro!seagoon.newcastle.edu.au!wombat.newcastle.edu.au!eepj
1992-10-20 15:41 Daniel Wengelin
1992-10-20 0:29 Ian Cunningham
1992-10-19 20:17 bloom-picayune.mit.edu!mintaka.lcs.mit.edu!spdcc!merk!alliant!russ
1992-10-19 13:02 MILLS,JOHN M.
1992-10-18 14:28 cis.ohio-state.edu!magnus.acs.ohio-state.edu!usenet.ins.cwru.edu!agate!do
1992-10-17 21:35 Hossein Moiin
1992-10-17 20:10 Don Gillies
1992-10-17 20:02 dog.ee.lbl.gov!hellgate.utah.edu!caen!zaphod.mps.ohio-state.edu!cis.ohio-
1992-10-17 15:18 mcsun!uknet!yorkohm!minster!mjl-b
1992-10-17 12:25 Mike Palmer
1992-10-17 10:36 Sean Case
1992-10-17 1:29 Michael A. Whelan
1992-10-16 23:14 news.orst.edu!umn.edu!micro.cs.umn.edu!hansen
1992-10-16 21:38 Tim Chambers
1992-10-15 21:41 Bob Kitzberger
1992-10-15 16:36 uwm.edu!cs.utexas.edu!sun-barr!news2me.EBay.Sun.COM!exodus.Eng.Sun.COM!br
1992-10-15 15:35 Val Kartchner
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