Add in the library doc the content of io.py

doc/library/tensor/index.txt

@@ -24,3 +24,4 @@ They are grouped into the following sections:
     signal/index
     utils
     extra_ops
+    io

doc/library/tensor/io.txt

+===================================================================
+:mod:`tensor.io` --  Tensor IO Ops
+===================================================================
+
+.. module:: tensor.io
+   :platform: Unix, Windows
+   :synopsis: Tensor IO Ops
+.. moduleauthor:: LISA
+
+File operation
+==============
+
+- Load from disk with the function :func:`load <theano.tensor.io.load>` and its associated op :class:`LoadFromDisk <theano.tensor.io.LoadFromDisk>`
+
+MPI operation
+=============
+- Non-blocking transfer: :func:`isend <theano.tensor.io.isend>` and :func:`irecv <theano.tensor.io.irecv>`.
+- Blocking transfer: :func:`send <theano.tensor.io.send>` and :func:`recv <theano.tensor.io.recv>`
+
+Details
+=======
+
+.. automodule:: theano.tensor.io
+    :members:
+

theano/tensor/io.py

@@ -256,18 +256,30 @@ class MPISendWait(Op):
 
 
 def isend(var, dest, tag):
+    """
+    Non blocking send
+    """
     return MPISend(dest, tag)(var)
 
 
 def send(var, dest, tag):
+    """
+    blocking send
+    """
     return MPISendWait(tag)(*isend(var, dest, tag))
 
 
 def irecv(shape, dtype, source, tag):
+    """
+    non-blocking receive
+    """
     return MPIRecv(source, tag, shape, dtype)()
 
 
 def recv(shape, dtype, source, tag):
+    """
+    blocking receive
+    """
     return MPIRecvWait(tag)(*irecv(shape, dtype, source, tag))