refine some codes

paddle/framework/executor.cc

@@ -74,16 +74,6 @@ void Executor::Run(const ProgramDesc& pdesc, Scope* scope) {
   for (auto& device_context : device_contexts_) {
     device_context->Wait();
   }
-  // // print tensor value
-  // for (auto& var : block.vars()) {
-  //   std::cout << var.name() << std::endl;
-  //   auto v = scope->FindVar(var.name());
-  //   const LoDTensor& t = v->Get<LoDTensor>();
-  //   for (int i = 0; i < t.numel(); ++i) {
-  //     std::cout << t.data<float>()[i] << " ";
-  //   }
-  //   std::cout << std::endl;
-  // }
 }
 
 }  // namespace framework

paddle/framework/executor_test.cc

@@ -130,6 +130,7 @@ std::once_flag set_variable_flag;
 template <typename T>
 void set_feed_variable(const std::vector<std::vector<T>>& inputs) {
   typedef std::vector<paddle::framework::Tensor> FeedInputs;
+  // Tensors in feed value variable will only be in CPUPlace
   Variable* g_feed_value = GetScope()->FindVar("feed_value");
   FeedInputs& feed_inputs = *(g_feed_value->GetMutable<FeedInputs>());
   auto size = inputs.size();
@@ -144,6 +145,7 @@ void set_feed_variable(const std::vector<std::vector<T>>& inputs) {
 template <typename T>
 std::vector<std::vector<T>> get_fetch_variable() {
   typedef std::vector<paddle::framework::Tensor> FetchOutputs;
+  // Tensors in fetch value variable will only be in CPUPlace
   Variable* g_fetch_value = GetScope()->FindVar("fetch_value");
   FetchOutputs& fetch_outputs = *(g_fetch_value->GetMutable<FetchOutputs>());
 

paddle/framework/scope.cc

@@ -66,15 +66,10 @@ void Scope::DropKids() {
 
 std::once_flag feed_variable_flag;
 
-template <typename T, typename... Args>
-std::unique_ptr<T> make_unique(Args&&... args) {
-  return std::unique_ptr<T>(new T(std::forward<Args>(args)...));
-}
-
 framework::Scope* GetScope() {
-  static std::unique_ptr<framework::Scope> g_scope =
-      make_unique<framework::Scope>();
+  static std::unique_ptr<framework::Scope> g_scope{nullptr};
   std::call_once(feed_variable_flag, [&]() {
+    g_scope.reset(new framework::Scope());
     g_scope->NewVar("feed_value");
     g_scope->NewVar("fetch_value");
   });

paddle/operators/feed_op.cc

@@ -33,7 +33,7 @@ class FeedOp : public framework::OperatorWithKernel {
 
     auto in_dim = tensors[col].dims();
     ctx->SetOutputDim("Out", in_dim);
-    // TODO(qijun) need to handle LodTensor later
+    // TODO(qijun): need to handle LodTensor later
   }
 
   framework::DataType IndicateDataType(

paddle/operators/fetch_op.cc

@@ -39,7 +39,7 @@ class FetchOp : public framework::OperatorWithKernel {
     tmp.Resize(input_dim);
     (*tensors)[col].Resize(input_dim);
 
-    // TODO(qijun) need to handle LodTensor later
+    // TODO(qijun): need to handle LodTensor later
   }
 
   framework::DataType IndicateDataType(