From: "Alain Coetmeur" Newsgroups: comp.parallel.mpi Subject: Re: Context in mpi Date: Mon, 28 Dec 1998 11:22:32 +0100 Organization: Informatique-CDC Message-Id: <767m9f$ak91@puligny.idt.cdc.fr> References: <75tq80$pt86@puligny.idt.cdc.fr> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit MPI have functions to manipulate "group"s which represent the list of the processes that are included in a communicator (for inter-communicator there are 2 groups) . there are function to translate rank from one group (often in a communicator) to a rank in another communicator, or detect the incoherence if process is absent in the other group. you can for example translate all ranks relative to a communicator into the rank in MPI_COMM_WORLD, or prefer to convert into another. ---------------------- My code has two sections, one that checks the buffers to see if I've already received a valid message, and another to receive a message from anyone who isn't in the buffer and is in the comm that the user passes me. My problem is checking in the 1st part (buffer check). I need to see if a source that provided the message in my buffer is in the passed comm. Is that possible in MPI (specifically MPICH)? I.e. I need an "int MPI_Comm_contains_source (comm, src)" function.