Re: ada paper critic

[Dale Stanbrough <dstanbro@bigpond.net.au>]

Ted Dennison wrote:

> > async abort is one counter example of this. The definition is such 
> > that programs take a hit in efficiency (or so i have read in this 
> > newsgroup).
> 
> You are missing the entire point. We could sit here all day and come
> up with weird constructions for each language in question that go slow
> on some compilers. What matters when you talk about speed is how
> quickly the code generated by your compiler runs your kinds of
> applications. If there's an unbelieveably slow feature in there, and
> that feature isn't used in this particular person's code in a tight
> loop somewhere, its not going to have any impact whatsoever on their
> percieved performance.


No, async abort requires the compiler to include all sorts of 
extra mutexes (or polling points) throughout the code, to ensure
that abort deferred actions are, well, abort deferred!

The original questions were (partly) about features in Ada that make
it go slow, and async abort is one of them. Don't use it and your
code goes fast. Even the presence of it in an if statement...

   if <some condition that is rarely true> then
      abort <some task>;
   end if;

causes the program to go slower. It doesn't really matter what
compiler you use.

Dale