Hi All, I am working on a MPI based server-client application. The number of clients are not fixed. The clients can come up at any time and will connect to server. The server runs two threads. Thread 1: opens a port, calls MPI_Comm_accept on a loop on MPI_COMM_SELF. Thread 2: Distributes works among the clients. When the client comes up, it calls MPI_Comm_connect to server. The problem I am facing is : how to terminate the blocking MPI_Comm_accept of Therad 1, once Thread2 is done with all the work? I tried the following thing which might not be legal to do: Thread2 calls MPI_Comm_connect (MPI_COMM_SELF) to Thread1's port. (created a new inter-communicator newComm) However, when I tried to send a non-blocking message to close the port from Thread2 (MPI_Isend, MPI_Wait) to Thread1 (MPI_Irecv, MPI_Wait) using newComm, the two threads wait forever. Any help regarding the termination of MPI_Comm_accept will be appreciated. Regards, Hirak _______________________________________________ discuss mailing list [email protected] To manage subscription options or unsubscribe: https://lists.mpich.org/mailman/listinfo/discuss