Make FunctionGraph() clone the input by default to don't have constant from the cache.

theano/compile/function_module.py

@@ -129,8 +129,7 @@ def std_fgraph(input_specs, output_specs, accept_inplace = False):
     updates = [spec.update for spec in input_specs if spec.update]
     orig_outputs = [spec.variable for spec in output_specs] + updates
 
-    inputs, outputs = gof.graph.clone(orig_inputs, orig_outputs)
-    fgraph = gof.fg.FunctionGraph(inputs, outputs)
+    fgraph = gof.fg.FunctionGraph(orig_inputs, orig_outputs)
 
     for node in fgraph.apply_nodes:
         if getattr(node.op, 'destroy_map', None):
@@ -143,7 +142,7 @@ def std_fgraph(input_specs, output_specs, accept_inplace = False):
     # We need to protect all immutable inputs from inplace operations.
     fgraph.attach_feature(
             Supervisor(input
-                for spec, input in zip(input_specs, inputs)
+                for spec, input in zip(input_specs, fgraph.inputs)
                 if not (spec.mutable or
                         (hasattr(fgraph, 'destroyers') and
                             fgraph.destroyers(input)))))

theano/gof/fg.py

@@ -74,7 +74,7 @@ class FunctionGraph(utils.object2):
 
     """
 
-    def __init__(self, inputs, outputs, features=None):
+    def __init__(self, inputs, outputs, features=None, clone=True):
         """
         Create an FunctionGraph which operates on the subgraph bound by the inputs and
         outputs sets.
@@ -85,7 +85,12 @@ class FunctionGraph(utils.object2):
         #TODO: document what variables are[not] set in the FunctionGraph when a feature
         is added via the constructor.  How constructed is the FunctionGraph?
 
+        :param clone: If true, we will clone the graph. This is
+        usefull to remove the constant cache problem.
+
         """
+        if clone:
+            inputs, outputs = graph.clone(inputs, outputs)
 
         self.execute_callbacks_time = 0
 

theano/gof/op.py

@@ -593,7 +593,7 @@ class Op(utils.object2, PureOp, CLinkerOp):
         #logger.debug('Compiling node %i of graph' % node_idx)
         if self._op_use_c_code:
             try:
-                e = FunctionGraph(*graph.clone(node.inputs, node.outputs))
+                e = FunctionGraph(node.inputs, node.outputs)
 
                 e_no_recycling = [new_o
                         for (new_o, old_o) in zip(e.outputs, node.outputs)

theano/gof/opt.py

@@ -631,7 +631,9 @@ def is_same_graph_with_merge(var1, var2, givens=None):
     givens = copied[2]
     # Create FunctionGraph.
     inputs = theano.gof.graph.inputs(vars)
-    fgraph = theano.gof.fg.FunctionGraph(inputs, vars)
+    # The clone isn't needed as we did a deepcopy and we cloning will
+    # break the mapping in givens.
+    fgraph = theano.gof.fg.FunctionGraph(inputs, vars, clone=False)
     # Perform Variable substitution.
     for to_replace, replace_by in givens.iteritems():
         fgraph.replace(to_replace, replace_by)

theano/gof/tests/test_destroyhandler.py

@@ -93,7 +93,7 @@ def inputs():
 
 
 def Env(inputs, outputs, validate=True):
-    e = FunctionGraph(inputs, outputs)
+    e = FunctionGraph(inputs, outputs, clone=False)
     e.attach_feature(destroyhandler.DestroyHandler())
     e.attach_feature(ReplaceValidate())
     if validate:

theano/gof/tests/test_fg.py

+import unittest
+
+import theano
+from theano.gof import CachedConstantError, FunctionGraph
+
+
+class TFunctionGraph(unittest.TestCase):
+    def test_constant_cache_error(self):
+        v = theano.tensor.constant(1)
+        assert v.cached
+        self.assertRaises(CachedConstantError, FunctionGraph, [], [v + 1],
+                          clone=False)
+
+    def test_clone(self):
+        v = theano.tensor.constant(1)
+        assert v.cached
+        FunctionGraph([], [v + 1])

theano/gof/tests/test_toolbox.py

@@ -3,7 +3,7 @@ from theano.gof.graph import Variable, Apply
 from theano.gof.type import Type
 from theano.gof.op import Op
 
-from theano.gof.fg import FunctionGraph as Env, InconsistencyError
+from theano.gof.fg import FunctionGraph, InconsistencyError
 from theano.gof.toolbox import *
 
 
@@ -61,14 +61,13 @@ def inputs():
     return x, y, z
 
 
-
 class TestNodeFinder:
 
     def test_straightforward(self):
         x, y, z = inputs()
         e0 = dot(y, z)
         e = add(add(sigmoid(x), sigmoid(sigmoid(z))), dot(add(x, y), e0))
-        g = Env([x, y, z], [e])
+        g = FunctionGraph([x, y, z], [e], clone=False)
         g.attach_feature(NodeFinder())
 
         assert hasattr(g, 'get_nodes')

theano/scalar/basic.py

@@ -2928,7 +2928,7 @@ class Composite(ScalarOp):
         self.name = rval
 
     def init_fgraph(self):
-        fgraph = FunctionGraph(*gof.graph.clone(self.inputs, self.outputs))
+        fgraph = FunctionGraph(self.inputs, self.outputs)
         gof.MergeOptimizer().optimize(fgraph)
         for node in fgraph.apply_nodes:
             if not isinstance(node.op, ScalarOp):