MPI Group (Process Group) Objects
MPI provides a process-group object (the MPI_Group handle) so the user can define and manipulate groups of processes and use them to define communicators. Groups are lightweight objects that are easily created and destroyed, while creation and destruction of communicators should be synchronized accross all the referenced processes.
Process groups cannot be changed once they are created. They can be combined to create new process groups.
Still needed
MPI functions, mapping to class and methods. How groups are used (to define communicators). Pointer to home_process and process_ref pages.