From: Ted Dennison <dennison@telepath.com>
Subject: Re: Using "delay until" in real-time
Date: Tue, 12 Dec 2000 19:57:32 GMT
Date: 2000-12-12T19:57:32+00:00 [thread overview]
Message-ID: <915vv7$vfo$1@nnrp1.deja.com> (raw)
In-Reply-To: 915p5n$p2j$1@nnrp1.deja.com
In article <915p5n$p2j$1@nnrp1.deja.com>,
Mike Silva <mjsilva@my-deja.com> wrote:
> It's Son of Patriot bug...
That's similar to what I called it. :-)
> I'm as far from an expert as you can get, but what if you defined your
> Iteration in terms of Tick (4*Tick in your case)? Seems like that
> should provide an exact representation (why do I feel like that
> comment will get me nailed?). Otherwise, keep your own Iteration
> count in a scalar and add it (first converted to a Time_Span) to a
> Start_time for each delay until.
I'm still feeling too dumb for not seeing this before to "nail" anyone
about it. Since Iteration_Hz in my old example was 4*tick, it sounds
like you are saying something like:
task Executive is
Iteration_Count : Natural := 0;
Start_Time : Ada.Real_Time.Time := Ada.Real_Time.Clock;
begin
loop
-- do work
Iteration_Count := Iteration_Count + 1;
delay until Start_Time + (Iteration_Count * Iteration_Hz);
end loop;
end Executive;
I see a couple of problems with this.
o This would only work for Natural'last iterations. That could be
accounted for though.
o Iteration_Count * Iteration_Hz is no different mathematicly from
adding Iteration_Hz to Start_Time Iteration_Count times, which is what I
was doing. You'd still get the same compounding round-off error.
> It's a very interesting question, and if I'm wrong I look forward to
> learning the right answer.
Very. I had a lot of enthusiasticly offered ideas here at work when I
asked about it yesterday.
--
T.E.D.
http://www.telepath.com/~dennison/Ted/TED.html
Sent via Deja.com
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next prev parent reply other threads:[~2000-12-12 19:57 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2000-12-12 16:27 Using "delay until" in real-time Ted Dennison
2000-12-12 18:01 ` Mike Silva
2000-12-12 19:57 ` Ted Dennison [this message]
2000-12-12 23:02 ` Mike Silva
2000-12-12 23:49 ` Ted Dennison
2000-12-18 6:26 ` Ray Blaak
2000-12-12 20:00 ` Ken Garlington
2000-12-12 20:40 ` Ted Dennison
2000-12-13 4:02 ` Ken Garlington
2000-12-13 14:29 ` Ted Dennison
2000-12-13 16:53 ` Larry Hazel
2000-12-13 17:41 ` Ted Dennison
2000-12-12 20:22 ` Keith Thompson
2000-12-12 20:54 ` Ted Dennison
2000-12-13 5:35 ` tmoran
2000-12-12 20:23 ` David C. Hoos, Sr.
2000-12-12 21:58 ` Ted Dennison
2000-12-12 23:18 ` Jeff Carter
2000-12-12 21:18 ` JP Thornley
2000-12-12 22:31 ` Ted Dennison
2000-12-13 8:02 ` Brian Orpin
2000-12-13 17:32 ` JP Thornley
2000-12-12 23:09 ` Ted Dennison
2000-12-13 7:43 ` Brian Orpin
2000-12-15 0:27 ` Frank
2000-12-19 7:50 ` Martin Gangkofer
2000-12-20 3:32 ` Ted Dennison
2000-12-20 5:29 ` tmoran
2000-12-20 7:59 ` Martin Gangkofer
2000-12-20 9:15 ` java servlets JF Harrison
2000-12-20 12:50 ` Using "delay until" in real-time Marin David Condic
2000-12-21 0:08 ` Alejandro R. Mosteo
2000-12-20 3:17 ` Ted Dennison
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