Fix 2: Use Isend and Irecv

Do i=1,n_neighbors Call MPI_Irecv(edge,len,MPI_REAL,nbr(i),tag, comm,request(i),ierr)Enddo Do i=1,n_neighbors Call MPI_Isend(edge, len, MPI_REAL, nbr(i), tag, comm, request(n_neighbors+i), ierr)EnddoCall MPI_Waitall(2*n_neighbors, request, statuses, ierr)

Do i=1,n_neighbors Call MPI_Irecv(edge,len,MPI_REAL,nbr(i),tag, comm,request(i),ierr) Enddo Do i=1,n_neighbors Call MPI_Isend(edge, len, MPI_REAL, nbr(i), tag, comm, request(n_neighbors+i), ierr) Enddo Call MPI_Waitall(2*n_neighbors, request, statuses, ierr)