[MPI3 Fortran] Agenda for MPI3 Fortran Working group next week

Jeff Squyres jsquyres at cisco.com
Thu Jun 4 10:34:15 CDT 2009

On Jun 3, 2009, at 11:47 AM, Hubert Ritzdorf wrote:

> An advantage of integer handles could be that the application programs
> are not able to send MPI communicator descriptions (derived types)
> as byte stream to other MPI processes and to overwrite the  
> corresponding
> (MPI private) info in the destination process.
> I have seen application programs which are sending derived user types
> including Fortran pointer descriptions as byte streams
> to other MPI processes and which are using data (ASSOCIATED) from  
> these
> Fortran pointer descriptions.
> If such program put/have communicators in such derived user types, the
> MPI library might use incorrect communicator
> data and cannot check this.

Hmm.  I'm not quite sure I understand; can you explain more?

Are you saying that some applications MPI_SEND the *communicator  
handle itself* to a peer?  If so, that's an erroneous program, no?   
I'd have to check, but I thought that MPI defined all handles to be  
local values only...?

Jeff Squyres
Cisco Systems

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