From mboxrd@z Thu Jan  1 00:00:00 1970
X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me
X-Spam-Level: 
X-Spam-Status: No, score=0.7 required=5.0 tests=BAYES_00,MSGID_RANDY
	autolearn=no autolearn_force=no version=3.4.4
X-Google-Language: ENGLISH,ASCII-7-bit
X-Google-Thread: 103376,f8311a3a7edd715
X-Google-Attributes: gid103376,public
X-Google-ArrivalTime: 2000-12-13 09:50:07 PST
Path: 
 supernews.google.com!sn-xit-02!supernews.com!216.227.56.88.MISMATCH!telocity-west!TELOCITY!news-spur1.maxwell.syr.edu!news.maxwell.syr.edu!nntp2.deja.com!nnrp1.deja.com!not-for-mail
From: Ted Dennison <dennison@telepath.com>
Newsgroups: comp.lang.ada
Subject: Re: Using "delay until" in real-time
Date: Wed, 13 Dec 2000 17:41:00 GMT
Organization: Deja.com
Message-ID: <918cba$tkm$1@nnrp1.deja.com>
References: <915jl7$jt5$1@nnrp1.deja.com>
 <ntvZ5.6802$bw.582745@news.flash.net> <9162gf$1or$1@nnrp1.deja.com>
 <3A37A974.C85EB683@mindspring.com>
NNTP-Posting-Host: 38.195.186.125
X-Article-Creation-Date: Wed Dec 13 17:41:00 2000 GMT
X-Http-User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US;
 0.6) Gecko/20001205
X-Http-Proxy: 1.1 x58.deja.com:80 (Squid/1.1.22) for client 38.195.186.125
X-MyDeja-Info: XMYDJUIDtedennison
Xref: supernews.google.com comp.lang.ada:3080
Date: 2000-12-13T17:41:00+00:00
List-Id: <comp.lang.ada>

In article <3A37A974.C85EB683@mindspring.com>,
  Larry Hazel <lhazel@mindspring.com> wrote:
>
>
> Why don't they have the same rounding problem in FORTRAN?  If 60 Hz
can't be
> done exactly in the hardware, language shouldn't matter.  Are they using
> different hardware where 60 Hz is exact?

Fortran has no such problem because Fortran has no tasking. It would be
forced to use the OS facilities, which would probably involve doing a
taskDelay X (where X is an intergral number of clock ticks). I could of
course do that in Ada too. But the issue I raised here deals with the
Ada mechanism, which is "delay until", and uses units of seconds. If the
OS's "ticks" can't be represented exactly in seconds, then the problem
arises.

--
T.E.D.

http://www.telepath.com/~dennison/Ted/TED.html


Sent via Deja.com
http://www.deja.com/