Transparent BSend

[niklas-uhl]

Just posting this here, because I had an idea for a future feature of KaMPIng

I looked a bit into MPI_Bsend. The user may/has to attach a buffer allocated by himself via MPI_Buffer_attach. If a message may not be directly received upon send, it is buffered. This may be an alternative to Isend when sending many small messages. The problem with the current implementation is, that it may fail if the buffer is full. Maybe we can overcome this by blocking upon a buffer overflow (assuming that we get no deadlock) until it has been emptied, making the whole buffered sending process transparent to the user. It also seems like MPI uses a rather simple approach for buffering to be generically applicable, we should do some implementation studies and maybe could provide the user with alternative buffering strategies to plug in.

[niklas-uhl]

Nothing that should be part of a publication and needs some additional thought