Re: Worst Case Execution Time Tool?

["annonymous" <annonymous@OrangeCT.Org>]

Ted writes:
> In most cases there is a smaller "worst case" available, but you have to
know a
> fair bit about the system to know what it is. For my real-time scheduler
> example, it could be that the list is implemented in an array with a hard
limit
> of 40 items, and it wouldn't be too horribly dificult for a code analyzer
to
> figure that out (although not trivial). On the other hand, it could be
that the
> limit is the number of items listed in a configuration file that is read
in at
> runtime. There's no possible way a tool could figure that out, because it
isn't
> really set at all.

There are many cases where it may be necessary to supply guidance to the
timing tools in the form of annotations.  As long as the tool can identify
these
or they are easy to spot by huge variations between measured and theoretical
times it is usually not difficult for the systems engineer to supply the
constraints
needed to do WCET analysis.  The tool needs to be able to accept this
information
information in the some form that can be correlated with the program
(usually
specialized comments).

-Tom