Objective: Use private communicators and attributes
Write a routine to circulate data to the next process, using a nonblocking
send and receive operation.
void Init_pipe( comm ) void ISend_pipe( comm, bufin, len, datatype, bufout ) void Wait_pipe( comm )A typical use is
Init_pipe( MPI_COMM_WORLD )
for (i=0; i<n; i++) {
ISend_pipe( comm, bufin, len, datatype, bufout );
Do_Work( bufin, len );
Wait_pipe( comm );
t = bufin; bufin = bufout; bufout = t;
}
What happens if Do_Work calls MPI routines?
127 What do you need to do to clean up Init_pipe?
127 How can you use a user-defined topology to determine the next process? (Hint: see MPI_Topo_test and MPI_Cartdim_get.)