Hi everyone, As mentioned in the MPI Session WG last time, Dominik and me broke down the existing dynamic MPI Session API into smaller and smaller chunks, extended it here and there, etc. We like to mention that we're not sure whether this is the right approach, but that it's worth to at least give it a try since it would simplify many things (even if it first looks more complicated). As promised, please find our current version attached to this Email. (The dummy_vars.h file is only to make the code more pleasant to look at in an IDE like eclipse). It's over 500 lines long, but please don't be shocked by this complexity. We really commented a lot and also included different cases. As a reminder: Dominik also agreed to give a presentation about this on 1st of August. I want to keep this Email short and just like to point out a description of thoughts, terminology, approaches, etc. in this source file. We have this file also in a github repos. If you like to have access to this to also iterate over it, please send us your github user name. All the best, Dominik & Martin -- Prof. Dr. Martin Schreiber Applied Mathematics / High Performance Scientific Comp. for PDEs Université Grenoble Alpes / Laboratoire Jean Kuntzmann, France For Time-X Euro-HPC project: Informatics / Computer Architecture and Parallel Systems Technical University of Munich, Germany