Fix pickling of FunctionGraph

theano/gof/fg.py

@@ -743,3 +743,19 @@ class FunctionGraph(utils.object2):
         for feature in self._features:
             e.attach_feature(feature)
         return e, equiv
+
+    def __getstate__(self):
+        """This is needed as some feature introduce instancemethod and
+        this is not pickable.
+        """
+        d = self.__dict__.copy()
+        for feature in self._features:
+            for attr in getattr(feature, "pickle_rm_attr", []):
+                del d[attr]
+        return d
+
+    def __setstate__(self, dct):
+        self.__dict__.update(dct)
+        for feature in self._features:
+            if hasattr(feature, "unpickle"):
+                feature.unpickle(self)

theano/gof/tests/test_fg.py

+import pickle
 import unittest
 
 import theano
 from theano.gof import CachedConstantError, FunctionGraph
+from theano import tensor as tt
 
 
 class TFunctionGraph(unittest.TestCase):
@@ -15,3 +17,10 @@ class TFunctionGraph(unittest.TestCase):
         v = theano.tensor.constant(1)
         assert v.cached
         FunctionGraph([], [v + 1])
+
+    def test_pickle(self):
+        v = tt.vector()
+        func = theano.gof.FunctionGraph([v], [v + 1])
+
+        s = pickle.dumps(func)
+        func2 = pickle.loads(s)

theano/gof/toolbox.py

@@ -105,6 +105,7 @@ class Bookkeeper(Feature):
 
 
 class History(Feature):
+    pickle_rm_attr = ["checkpoint", "revert"]
 
     def __init__(self):
         self.history = {}
@@ -114,6 +115,13 @@ class History(Feature):
             raise AlreadyThere("History feature is already present or in"
                                " conflict with another plugin.")
         self.history[fgraph] = []
+        # Don't call unpickle here, as ReplaceValidate.on_attach()
+        # call to History.on_attach() will call the
+        # ReplaceValidate.unpickle and not History.unpickle
+        fgraph.checkpoint = lambda: len(self.history[fgraph])
+        fgraph.revert = partial(self.revert, fgraph)
+
+    def unpickle(self, fgraph):
         fgraph.checkpoint = lambda: len(self.history[fgraph])
         fgraph.revert = partial(self.revert, fgraph)
 
@@ -144,14 +152,28 @@ class History(Feature):
 
 
 class Validator(Feature):
+    pickle_rm_attr = ["validate", "consistent"]
 
     def on_attach(self, fgraph):
         for attr in ('validate', 'validate_time'):
             if hasattr(fgraph, attr):
                 raise AlreadyThere("Validator feature is already present or in"
                                    " conflict with another plugin.")
+        # Don't call unpickle here, as ReplaceValidate.on_attach()
+        # call to History.on_attach() will call the
+        # ReplaceValidate.unpickle and not History.unpickle
+        fgraph.validate = partial(self.validate, fgraph)
+        fgraph.consistent = partial(self.consistent, fgraph)
 
-        def validate():
+    def unpickle(self, fgraph):
+        fgraph.validate = partial(self.validate, fgraph)
+        fgraph.consistent = partial(self.consistent, fgraph)
+
+    def on_detach(self, fgraph):
+        del fgraph.validate
+        del fgraph.consistent
+
+    def validate(self, fgraph):
         t0 = time.time()
         ret = fgraph.execute_callbacks('validate')
         t1 = time.time()
@@ -159,32 +181,37 @@ class Validator(Feature):
             fgraph.profile.validate_time += t1 - t0
         return ret
 
-        fgraph.validate = validate
-
-        def consistent():
+    def consistent(self, fgraph):
         try:
             fgraph.validate()
             return True
         except Exception:
             return False
-        fgraph.consistent = consistent
-
-    def on_detach(self, fgraph):
-        del fgraph.validate
-        del fgraph.consistent
 
 
 class ReplaceValidate(History, Validator):
+    pickle_rm_attr = ["replace_validate", "replace_all_validate",
+                      "replace_all_validate_remove",
+                      #Parent pickle_rm_attr
+                      "consistent", "validate", "checkpoint", "revert"
+    ]
 
     def on_attach(self, fgraph):
-        History.on_attach(self, fgraph)
-        Validator.on_attach(self, fgraph)
-        for attr in ('replace_validate', 'replace_all_validate'):
+        for attr in ('replace_validate', 'replace_all_validate',
+                     'replace_all_validate_remove'):
             if hasattr(fgraph, attr):
                 raise AlreadyThere("ReplaceValidate feature is already present"
                                    " or in conflict with another plugin.")
+        History.on_attach(self, fgraph)
+        Validator.on_attach(self, fgraph)
+        self.unpickle(fgraph)
+
+    def unpickle(self, fgraph):
+        History.unpickle(self, fgraph)
+        Validator.unpickle(self, fgraph)
         fgraph.replace_validate = partial(self.replace_validate, fgraph)
-        fgraph.replace_all_validate = partial(self.replace_all_validate, fgraph)
+        fgraph.replace_all_validate = partial(self.replace_all_validate,
+                                              fgraph)
         fgraph.replace_all_validate_remove = partial(
             self.replace_all_validate_remove, fgraph)