Feature/remove global scope (#4950)

* Unify `set_feed_variable` to one method

* Move global scope to python, not in C++

paddle/framework/feed_fetch_method.h

@@ -21,12 +21,12 @@ limitations under the License. */
 namespace paddle {
 namespace framework {
 
-void SetFeedVariable(const LoDTensor& input, const std::string& var_name,
-                     size_t index) {
+void SetFeedVariable(Scope* scope, const LoDTensor& input,
+                     const std::string& var_name, size_t index) {
   // If var_name Variable is not found in GlobalScope, a new variable will
   // be created.
   VLOG(3) << "SetFeedVariable name=" << var_name << " index=" << index;
-  Variable* g_feed_value = GetGlobalScope().Var(var_name);
+  Variable* g_feed_value = scope->Var(var_name);
   auto& feed_inputs =
       *(g_feed_value->GetMutable<std::vector<paddle::framework::LoDTensor>>());
   if (index >= feed_inputs.size()) {
@@ -38,10 +38,11 @@ void SetFeedVariable(const LoDTensor& input, const std::string& var_name,
   feed_inputs[index].set_lod(input.lod());
 }
 
-LoDTensor& GetFetchVariable(const std::string& var_name, size_t index) {
+LoDTensor& GetFetchVariable(const Scope& scope, const std::string& var_name,
+                            size_t index) {
   // Since we want to fetch LodTensor from a variable, the variable must
   // be created alreadly.
-  Variable* g_fetch_value = GetGlobalScope().FindVar(var_name);
+  Variable* g_fetch_value = scope.FindVar(var_name);
   PADDLE_ENFORCE(g_fetch_value->IsType<FeedFetchList>(),
                  "Only %s can be invoked by GetFetchVariable",
                  typeid(FeedFetchList).name());

paddle/framework/scope.cc

@@ -72,13 +72,5 @@ void Scope::DeleteScope(Scope* scope) {
   delete scope;
 }
 
-framework::Scope& GetGlobalScope() {
-  static framework::Scope* g_scope = nullptr;
-  if (g_scope == nullptr) {
-    g_scope = new framework::Scope();
-  }
-  return *g_scope;
-}
-
 }  // namespace framework
 }  // namespace paddle

paddle/framework/scope.h

@@ -74,8 +74,5 @@ class Scope {
 
   DISABLE_COPY_AND_ASSIGN(Scope);
 };
-
-framework::Scope& GetGlobalScope();
-
 }  // namespace framework
 }  // namespace paddle

paddle/pybind/pybind.cc

@@ -219,8 +219,7 @@ All parameter, weight, gradient are variables in Paddle.
       .def(py::init<>())
       .def("new_scope", [](Scope &self) -> Scope * { return &self.NewScope(); },
            py::return_value_policy::reference)
-      .def("drop_kids", &Scope::DropKids)
-      .def_static("global_scope", &GetGlobalScope);
+      .def("drop_kids", &Scope::DropKids);
 
   //! @note: Be careful! PyBind will return std::string as an unicode, not
   //! Python str. If you want a str object, you should cast them in Python.
@@ -451,10 +450,9 @@ All parameter, weight, gradient are variables in Paddle.
 
   py::class_<framework::Executor>(m, "Executor")
       .def(py::init<std::vector<platform::Place> &>())
-      .def("run",
-           [](Executor &self, ProgramDescBind *program_bind, int block_id) {
-             framework::Scope &global_scope = GetGlobalScope();
-             self.Run(*program_bind->Proto(), &global_scope, block_id);
+      .def("run", [](Executor &self, ProgramDescBind *program_bind,
+                     Scope *scope, int block_id) {
+        self.Run(*program_bind->Proto(), scope, block_id);
       });
 
   m.def("unique_integer", UniqueIntegerGenerator);

python/paddle/v2/framework/executor.py

 import paddle.v2.framework.core as core
 from paddle.v2.framework.framework import Block, Program
 
+g_scope = core.Scope()
+
 
 class Executor(object):
     def __init__(self, places):
@@ -20,10 +22,14 @@ class Executor(object):
             feed,
             fetch_list,
             feed_var_name='feed',
-            fetch_var_name='fetch'):
+            fetch_var_name='fetch',
+            scope=None):
         if not isinstance(program, Program):
             raise TypeError()
 
+        if scope is None:
+            scope = g_scope
+
         program = program.clone()
         global_block = program.global_block()
         feed_var = global_block.create_var(
@@ -38,7 +44,7 @@ class Executor(object):
                 inputs={'X': [feed_var]},
                 outputs={'Out': [out]},
                 attrs={'col': i})
-            core.set_feed_variable(feed[name], feed_var.name, i)
+            core.set_feed_variable(scope, feed[name], feed_var.name, i)
 
         fetch_var = global_block.create_var(
             name=fetch_var_name,
@@ -51,8 +57,8 @@ class Executor(object):
                 outputs={'Out': [fetch_var]},
                 attrs={'col': i})
 
-        self.executor.run(program.desc, 0)
+        self.executor.run(program.desc, scope, 0)
         return [
-            core.get_fetch_variable(fetch_var_name, i)
+            core.get_fetch_variable(scope, fetch_var_name, i)
             for i in xrange(len(fetch_list))
         ]

python/paddle/v2/framework/tests/test_feed_fetch_method.py

@@ -5,6 +5,7 @@ import numpy as np
 
 class TestFeedFetch(unittest.TestCase):
     def test_feed_fetch(self):
+        scope = core.Scope()
         place = core.CPUPlace()
         input_array = np.ones((4, 4, 6)).astype("float32")
         input_array[0, 0, 0] = 3
@@ -12,9 +13,9 @@ class TestFeedFetch(unittest.TestCase):
         input_tensor = core.LoDTensor([[0, 2, 4]])
         input_tensor.set(input_array, place)
 
-        core.set_feed_variable(input_tensor, "feed", 0)
+        core.set_feed_variable(scope, input_tensor, "feed", 0)
 
-        output_tensor = core.get_fetch_variable("feed", 0)
+        output_tensor = core.get_fetch_variable(scope, "feed", 0)
 
         output_lod = output_tensor.lod()
         self.assertEqual(0, output_lod[0][0])