Add weakref to random state to distinguish them from other shared variables

theano/sandbox/rng_mrg.py

@@ -6,6 +6,7 @@ http://www.iro.umontreal.ca/~simardr/ssj/indexe.html
 
 """
 import warnings
+import weakref
 
 import numpy
 
@@ -1220,6 +1221,8 @@ class MRG_RandomStreams(object):
             u = self.pretty_return(node_rstate,
                                    *mrg_uniform.new(node_rstate,
                                                     ndim, dtype, size))
+        # Add a reference to distinguish from other shared variables
+        node_rstate.rng_owner = weakref.ref(self)
         r = u * (high - low) + low
 
         if u.type.broadcastable != r.type.broadcastable: