Re: [Freepooma-devel] Reviewing thread-safety

[Richard Guenther]

ron hylton wrote:
> Richard,
> 
> This isn't an answer to your question but it is thread-safety related :-)
> 
> In my applications I use Pooma to solve a large number of uncoupled
> problems that are individually too small so far to be worth splitting
> across processors.  In this case I would like to be able to use multiple
> instances of Pooma in independent threads, but this currently doesn't
> work because of the existence of some global data for scheduling and
> statistics.
> 
> One item on my to-do list is to make an "Object Pooma" that wraps the
> currently global data so I can instantiate multiple Pooma's.  This looks
> relatively straightforward to me but I have no experience with OpenMP or
> MPI and I don't know whether these would break if I went down this route.
> 
> Does anyone have any views on the feasibility of Object Pooma?

Hmm, I don't think an Object Pooma will be a good idea.  Instead you
could try issuing the complete iterates to different threads.  I once
tried this with OpenMP, but had some problems.  With natively using
pthreads this should be simpler, and one may share some of the
ideas used with the asynchronous completion of MPI requests.  Making
this sort of threading play nicely with OpenMP and MPI is of course
another thing.  I.e. you would massage (aka replace)
Threads/IterateSchedulers/SerialAsync to be a pthread based
implementation.  This may stress thread-safety of the library much, though.

Richard.