0 init 1 init 2 init 0 Irecv 1 2000 1 Isend 0 2000 2 Irecv 1 3000 0 Irecv 2 3000 1 Isend 2 3000 2 Isend 0 3000 0 waitAll 1 waitAll 2 waitAll 0 finalize 1 finalize 2 finalize