[Mpi3-bwcompat] MPI timer requests

[Jeff Squyres]

On Mar 7, 2011, at 7:04 AM, Supalov, Alexander wrote:

> The idea of separating the timeout functionality from the actual request(s) that are being waited upon looks interesting to me. One could probably want to timeout on a non-blocking spawn or connect/accept, etc., as well. Or on any non-blocking collective, for that matter. Would this proposal work there?

Yes, timers will work anywhere -- they're requests, like any other request.  So you can use them with any MPI_WAIT* / MPI_TEST* functions.  

As I understand it, the FT group has some internal proposals about non-blocking spawn, connect, accept, etc.  

Our idea here was to minimally impact other, existing parts of MPI.  A timer request is a standalone item; it can complete independent of any other request (e.g., a non-blocking p2p or collective communication, spawn, accept, connect, ..etc.).  As Fab stated, completion of a timer intentionally has no other connotation about other incomplete actions.

Dave's point about generalized requests is a good one, though -- I need to go think about that and convince myself that what we're talking about isn't syntactic sugar and/or why it's better to be in the MPI implementation.


-- 
Jeff Squyres
jsquyres_at_[hidden]
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