Demo of a non-blocking message chain

Author: mlouhivu

demos/mpi-msg-chain.py

@@ -0,0 +1,24 @@
+from mpi4py import MPI
+import numpy
+
+comm = MPI.COMM_WORLD
+rank = comm.Get_rank()
+size = comm.Get_size()
+
+data = numpy.arange(10, dtype=float) * (rank + 1)  # send buffer
+buffer = numpy.zeros(10, dtype=float)              # receive buffer
+
+tgt = rank + 1
+src = rank - 1
+if rank == 0:
+    src = MPI.PROC_NULL
+if rank == size - 1:
+    tgt = MPI.PROC_NULL
+
+req = []
+req.append(comm.Isend(data, dest=tgt))
+req.append(comm.Irecv(buffer, source=src))
+
+MPI.Request.waitall(req)
+
+print('[{0:2}] Received: {1}'.format(rank, buffer))