Add some docs to FunctionGraph and minor changes of function_module.copy()

theano/compile/function_module.py

@@ -571,27 +571,13 @@ class Function(object):
             # copy SymbolocKits
             ins, outs = copy.deepcopy([self.maker.inputs, self.maker.outputs])
 
-            # get copied input, output variables
-            in_vars = [ i.variable for i in ins ]
-            out_vars = [ o.variable for o in outs ]
-
-            # contruct memo that map old variables to new variables
-            memo = {}
-            for old_i, new_i in zip([i.variable for i in self.maker.inputs],
-                                        in_vars):
-                memo[old_i] = new_i
-            for old_o, new_o in zip([o.variable for o in self.maker.outputs],
-                                        out_vars):
-                memo[old_o] = new_o
-
-            # contruct new fgraph with new vars and complete the memo
-            memo = clone_get_equiv( in_vars, out_vars, memo )
-            new_fgraph = FunctionGraph(in_vars, out_vars)
-
-            # re-initialize new FunctionMaker
+            # copy fgraph and get memo
             maker = self.maker
+            fg_cpy, memo = maker.fgraph.clone_get_equiv(attach_feature=False)
+
+            # use copied ins, outs and fgraph to init a maker
             new_maker = FunctionMaker(inputs=ins, outputs=outs, mode=maker.mode,
-                                        fgraph=new_fgraph, profile=maker.profile,
+                                        fgraph=fg_cpy, profile=maker.profile,
                                         accept_inplace=maker.accept_inplace,
                                         function_builder=maker.function_builder,
                                         on_unused_input=maker.on_unused_input)
@@ -602,20 +588,30 @@ class Function(object):
             storage_map = self.fn.storage_map
             for key in storage_map.keys():
                 # output_storages should not be shared
-                if key not in self.maker.fgraph.outputs and \
-                    memo.has_key(key):
+                # if key not in self.maker.fgraph.outputs and \
+                #     memo.has_key(key):
                 new_storage_map[memo[key]] = storage_map[key]
 
-            # copy input storages and link function with new storage_map
-            input_storage = copy.copy([getattr(i, 'value', None) for i in ins])
-            new_func = new_maker.create(input_storage, storage_map=new_storage_map)
+            # copy input storages if it's mutable
+            input_storage = [] 
+            for i in self.maker.inputs:
+                storage = getattr(i, 'value', None) 
+                if isinstance(i.variable, theano.tensor.Constant) or\
+                    not i.mutable:
+                    input_storage.append(storage )
+                else:
+                    input_storage.append( copy.deepcopy[storage])
+
+            new_func = new_maker.create(input_storage, \
+                                storage_map=new_storage_map)
 
             # share immutable SharedVariable's storage
-            for (input, _1, _2), here, there in zip(self.indices,
-                                                    self.input_storage,
-                                                    new_func.input_storage):
-                if not input.mutable:
-                    there.data = here.data
+            # for (input, _1, _2), here, there in zip(self.indices,
+            #                                         self.input_storage,
+            #                                         new_func.input_storage):
+            #     if isinstance(i.variable, theano.tensor.Constant) or \
+            #         not input.mutable:
+            #         there.data = here.data
 
             return new_func
 

theano/compile/tests/test_function_module.py

@@ -243,7 +243,7 @@ class T_function(unittest.TestCase):
 
     def test_copy_share_memory(self):
         x = T.fscalar('x')
-        y = T.tanh((x+2)/(x+0.2)**2)
+        y = T.tanh((x+2)/(x-0.2)**2)
 
         # test for PerformaLinker, will cover VM_linker later
         ori = theano.function([x], [y], mode="FAST_COMPILE")
@@ -256,13 +256,11 @@ class T_function(unittest.TestCase):
         fgraph_cpy = cpy.maker.fgraph
 
         # assert intermediate and Constants storages are shared
-        i_o_variables = fgraph_cpy.inputs
+        i_o_variables = fgraph_cpy.inputs + fgraph_cpy.outputs
         ori_storages = storage_map_ori.values()
         for key in storage_map_cpy.keys():
             if key not in i_o_variables or isinstance(key, theano.tensor.Constant):
-                print key
                 storage = storage_map_cpy[key]
-                print [ storage is s for s in ori_storages]
                 self.assertTrue( any([ storage is s for s in ori_storages]))
 
         # assert storages of SharedVariable without updates are shared

theano/gof/fg.py

@@ -276,8 +276,19 @@ class FunctionGraph(utils.object2):
             return True
         return False
 
-    # import #
-    def __import_r__(self, variable, reason):
+    ### import ###
+    def __import_r__(self, variables, reason):
+        """
+        Import variables to this FunctionGraph and also their apply_node,
+        if those nodes are not in this graph.
+        ----------------------
+        Parameters;
+            variables -- Iterable if variables needed to import
+            reason -- String. Reason.
+        ----------------------
+        Returns:
+            None
+        """
         global NullType
         if NullType is None:
             from .null_type import NullType
@@ -296,6 +307,12 @@ class FunctionGraph(utils.object2):
         self.variables.add(variable)
 
     def __import__(self, apply_node, check=True, reason=None):
+        """
+        Given an apply_node, recursively search from this node to know graph,
+        and then add all unknown variables and apply_nodes to this graph.
+        """
+        node = apply_node
+
         # We import the nodes in topological order. We only are interested
         # in new nodes, so we use all variables we know of as if they were the input set.
         # (the functions in the graph module only use the input set to