added live mpi test

theano/tensor/tests/_test_mpi_roundtrip.py

+# Run using
+# mpiexec -np 2 python _test_mpi_roundtrip.py
+
+
 from mpi4py import MPI
 comm = MPI.COMM_WORLD
 import theano
@@ -8,26 +12,29 @@ from sys import stdout
 
 rank = comm.Get_rank()
 size = comm.Get_size()
-print size
-print rank
 
-shape = (10, 10)
+shape = (2, 2)
 dtype = 'float32'
 
+mode = theano.Mode(optimizer=None, linker='py')
+
 if rank == 0:
     x = theano.tensor.matrix('x', dtype=dtype)
-    y = x + 1
+    # y = x + x
+    # send_request = send(y, 1, 11)
     send_request = send(x, 1, 11)
 
     z = recv(shape, dtype, 1, 12)
 
-    f = theano.function([x], [send_request, z])
+    f = theano.function([x], [send_request, z], mode=mode)
 
     xx = np.random.rand(*shape).astype(dtype)
+    # expected = (xx + 1) * 2
+    expected = xx * 2
 
-    zz = f(xx)
+    _, zz = f(xx)
 
-    same = np.linalg.norm(zz - (xx+1)*2) < .001
+    same = np.linalg.norm(zz - expected) < .001
     stdout.write(str(same))
 
 if rank == 1:
@@ -36,6 +43,6 @@ if rank == 1:
     z = y * 2
     send_request = send(z, 0, 12)
 
-    f = theano.function([], send_request)
+    f = theano.function([], send_request, mode=mode)
 
     f()

theano/tensor/tests/test_mpi.py

@@ -16,4 +16,3 @@ def test_send():
     sendnode = y.owner.inputs[0].owner
     assert sendnode.op.dest == 1
     assert sendnode.op.tag  == 11
-