Re: Worst Case Execution Time Tool?

[StationSteve <Steven.Suchting@computer.org>]

Ok, do you have time to educate me a little bit?
Why would a tool have to be "pretty darn smart" to measure the worst-case execution
time of a list traversal?  What's the big driver in making such a thing hard to do?
How hard are we talking?  Ph.D/New Theory Required hard or Grad Student Thesis hard
or Kappa-Key undergrad hard or Lock-the-new-hire-in-the-lab-just-get-it-done hard?

Ted Dennison wrote:

> In article <3C0F7B36.52960668@computer.org>, StationSteve says...
> >
> >Of course.  Er, I mean sorry, I guess I should have said that I was looking
> >for a *practical* tool that could *productively* address a *real world*
> >problem! ;-)
> >
> >Ted Dennison wrote:
> >> Ah. So we aren't looking for something that can handle any old program
> >> (which it still seems to be would be reducable to the Halting Problem), but
> >> rather one that can handle programs that fit certian restrictions.
>
> :-)
>
> For that to be accurate though, you'd have to be able to say that all programs
> that don't fit within the restrictions are not "real world" programs for some
> reason. That could be the case I suppose. However, I'd bet quite a few "real
> world" programs wouldn't meet all the restrictions in any such existing tool.
> Certianly "No recursion" and "no loops with a dynamicly determined amount of
> iterations" (which is what Stuart said) would take out a great deal of the "real
> world" code I have seen.
>
> For instance, just about anything that handles terminated I/O would be out. A
> lot of dynamic data structure code would be out too. I could easily see where a
> hard realtime app might want to measure the worst-case execution time of a list
> traversal (eg: the scheduler's list of scheduled tasks). It'd be a pretty darn
> smart tool if it could handle that, no matter how the list is implemented.
>
> ---
> T.E.D.    homepage   - http://www.telepath.com/dennison/Ted/TED.html
>
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