The server process

The job of the server process is simple: receive a request from any worker within the world = MPI_COMM_WORLD communicator, and return an array of CHUNKSIZE random numbers to that process if the request > 0. Otherwise, exit:

do {
   MPI_Recv(&request, 1, MPI_INT, MPI_ANY_SOURCE, REQUEST, world,
            &status);
   if (request) {
      for (i = 0; i < CHUNKSIZE; i++) rands[i] = random();
      MPI_Send(rands, CHUNKSIZE, MPI_INT, status.MPI_SOURCE,
               REPLY, world);
   }
} while ( request > 0 );