Merge pull request #10023 from reyoung/feature/DtorOfPE

Correctly implement destructor of ParallelExecutor

paddle/fluid/framework/parallel_executor.cc

@@ -44,6 +44,7 @@ class ParallelExecutorPrivate {
 #endif
 
   std::vector<std::tuple<std::string, proto::VarType::Type, bool>> var_types_;
+  bool own_local_scope;
 };
 
 std::vector<Scope *> &ParallelExecutor::GetLocalScopes() {
@@ -63,11 +64,13 @@ ParallelExecutor::ParallelExecutor(
   // Step 1. Bcast the params to devs.
   // Create local scopes
   if (local_scopes.empty()) {
+    member_->own_local_scope = true;
     member_->local_scopes_.emplace_back(member_->global_scope_);
     for (size_t i = 1; i < member_->places_.size(); ++i) {
       member_->local_scopes_.emplace_back(&scope->NewScope());
     }
   } else {
+    member_->own_local_scope = false;
     PADDLE_ENFORCE_EQ(member_->places_.size(), local_scopes.size());
     for (size_t i = 0; i < member_->places_.size(); ++i) {
       member_->local_scopes_.emplace_back(local_scopes[i]);
@@ -231,5 +234,13 @@ void ParallelExecutor::FeedAndSplitTensorIntoLocalScopes(
   }
 }
 
+ParallelExecutor::~ParallelExecutor() {
+  if (member_->own_local_scope) {
+    for (size_t i = 1; i < member_->local_scopes_.size(); ++i) {
+      member_->global_scope_->DeleteScope(member_->local_scopes_[i]);
+    }
+  }
+}
+
 }  // namespace framework
 }  // namespace paddle

paddle/fluid/framework/parallel_executor.h

@@ -42,6 +42,8 @@ class ParallelExecutor {
                             const std::vector<Scope*>& local_scopes,
                             bool allow_op_delay);
 
+  ~ParallelExecutor();
+
   std::vector<Scope*>& GetLocalScopes();
 
   /**