[pooma-dev] Re: [PATCH] Fix deadlocks in MPI reduction evaluators

[Richard Guenther]

On Thu, 15 Jan 2004, Jeffrey D. Oldham wrote:

> I appreciate your finding the difficulty and your taking the time to
> explain the problem.  I am reluctant to add code that is known to be
> broken for some situations.  Is there a way to mark the code so 1) the
> known brokenness is marked and 2) the program asks sensibly when the
> brokenness is experienced?

I understand your concerns.  I can add a comment describing the brokenness
(which boils down to "we don't have a collective barrier abstraction" -
blockAndEvaluate() is _not_ collective).  Detecting it would be possible
by asserting that each context at least does either Send or Compute.

I'll think some more about the collective barrier -- maybe extend the
generation tracking to allow blocking (collectively) for completion of the
generation at endGeneration() time.

Richard.

--
Richard Guenther <richard dot guenther at uni-tuebingen dot de>
WWW: http://www.tat.physik.uni-tuebingen.de/~rguenth/