Re: Strange behaviour of delay in Windows XP

["Randy Brukardt" <randy@rrsoftware.com>]

"michael bode" <m.g.bode@web.de> wrote in message 
news:i8lcl2$f0i$1@news.eternal-september.org...
...
> But I have a (or rather 2) Dell Vostro MT 220 PC where the actual delay
> is about 2.7s instead. Tested with GNAT GPL 2008 and 2009 on XP. Another
> almost identical Vostro MT 230 works as expected. And to make it more
> interesting when I brought the Vostro 220 from my lab to my office it
> worked as expected. Back to the lab I got the 2.7s delay again. Most of
> the time. Sometimes I got 1.0xxs. There was no noticeable CPU load
> during the tests. Then I booted the machine from a Ubuntu Live CD and
> tested with the program compiled under Debian Lenny. It worked as
> expected: 1.000xxx seconds delay.
>
> Any ideas or should I call a feng shui master?

I have no ideas about your specific problem, but we found when building Claw 
that delays were quite unreliable on Windows. One compiler insisted on 
delaying a full clock tick (0.1s) even for "delay 0.0;" (used to mean 
"yield"; Ada 2012 will actually have a call named "yield") -- this was a 
disaster as we were using it in the primary message loop (adding 0.1s per 
message slowed apps to a crawl). All were inaccurate to some extent or 
another. All were improved to some extent or another after we filed bug 
reports.

It wouldn't be hard to do something in an implementation of "delay" that 
caused a time explosion in some case or another.

                                  Randy.