Hi Doug, Douglas Miller wrote:

The example is as I intended. The usage I've been promoting is that all team members do the join and leave. This is the only way to get all threads participating.

Sorry if I'm forgetting something we already discussed -- in your example, are the t != 0 threads blocking inside MPI_Endpoint_join()? My guess is no, since the t == 0 thread which needs to make the Allgather call needs to come out. Then how will MPI use these threads (they need to be under MPI's control to be used). -- Pavan -- Pavan Balaji http://www.mcs.anl.gov/~balaji