Re: Ada 95 tasking problems with Ada 83 code

["Pat Rogers" <progers@NOclasswideSPAM.com>]

"Richard Riehle" <laoXhai@ix.netcom.com> wrote in message
news:39B542BE.E0AFA887@ix.netcom.com...
>
> Pat Rogers wrote:
>
> > "Richard Riehle" <laoXhai@ix.netcom.com> wrote in message
> > news:39B52DFC.6EF265D3@ix.netcom.com...
> >
> > > All that being said, we don't know enough details of Wayne's
design to
> > > make absolute pronouncements about how he should proceed, but I
> > > think you would agree that anyone designing a task-based system
ought
> > > to have some awareness of the issues related to schedulability.
> >
> > Certainly for a real-time system.  But for "just" a concurrent
> > program, I think a full schedulability analysis is overkill.
>
> OK.  I will agree with that.   We simply had different models
immediately
> in mind.   The "pool of tasks" design will be different from a
real-time model
> where each task performs some unique action, and deadlines and
schedulability
> are critical.   Also, we are still not sure  what Wayne is doing, so
he has some
> work to do in deciding which approach is more appropriate.   I am
sure you
> agree, though, that anyone planning a design using concurrent tasks
should
> have a little familiarity with the issues related to scheduling,
even when
> using a pool of similar tasks, especially if  those tasks are
communicating with each
> other.

Yes, definitely, if by scheduling you mean the issues of deadlock,
indefinite postponement, livelock, and so on -- i.e., what it means
for a concurrent program to be "correct" --  as well as the
ramifications of task interactions (e.g. context switching) on
performance.  Absent deadlines, though, I think those are sufficient
(as if those were simple subjects!).

A pleasure as always,

pat