This has been debated in the standard. There are a few tickets open for this issue. https://svn.mpi-forum.org/trac/mpi-forum-web/ticket/478 https://svn.mpi-forum.org/trac/mpi-forum-web/ticket/479 https://svn.mpi-forum.org/trac/mpi-forum-web/ticket/480 -- Pavan

On Oct 31, 2015, at 6:12 AM, Marek Tomáštík <[email protected]> wrote:

Hello, I am trying to find out what should happen, according to the MPI 3.0* standard, in the following scenario: 1) process 0 initiates a nonblocking send operation with MPI_Issend 2) process 1 matches the message with MPI_Mprobe, but doesn't yet call MPI_Mrecv/MPI_Imrecv 3) process 0 calls MPI_Cancel to cancel the send.

I cannot think of anything the cancel operation could do that wouldn't contradict either the specification of MPI_Cancel, or of the matched receive functions. How can this situation be handled in compliance with the standard?

Thank you in advance, Marek Tomáštík

*or 3.1 -- I believe there weren't any changes in this area? _______________________________________________ mpi-forum mailing list [email protected] http://lists.mpi-forum.org/mailman/listinfo.cgi/mpi-forum