Add an argument in Executor.Run to allow users to choose whether to create and destroy variables every time. (#9242)

Author: Xreki

paddle/fluid/framework/executor.cc

@@ -185,7 +185,7 @@ void Executor::Run(const ProgramDesc& program, Scope* scope,
                    std::map<std::string, const LoDTensor*>& feed_targets,
                    std::map<std::string, LoDTensor*>& fetch_targets,
                    const std::string& feed_holder_name,
-                   const std::string& fetch_holder_name) {
+                   const std::string& fetch_holder_name, bool create_vars) {
   platform::RecordBlock b(kProgramId);
   bool has_feed_ops =
       has_feed_operators(program.Block(0), feed_targets, feed_holder_name);
@@ -255,7 +255,7 @@ void Executor::Run(const ProgramDesc& program, Scope* scope,
     }
   }
 
-  Run(*copy_program, scope, 0, true, true);
+  Run(*copy_program, scope, 0, create_vars, create_vars);
 
   // obtain the data of fetch_targets from fetch_holder
   for (auto* op : global_block->AllOps()) {

paddle/fluid/framework/executor.h

@@ -54,7 +54,8 @@ class Executor {
            std::map<std::string, const LoDTensor*>& feed_targets,
            std::map<std::string, LoDTensor*>& fetch_targets,
            const std::string& feed_holder_name = "feed",
-           const std::string& fetch_holder_name = "fetch");
+           const std::string& fetch_holder_name = "fetch",
+           bool create_vars = true);
 
   static std::unique_ptr<ExecutorPrepareContext> Prepare(
       const ProgramDesc& program, int block_id);