Disable multi-thread

paddle/fluid/framework/parallel_executor.cc

@@ -84,8 +84,8 @@ struct OpHandle {
 
   virtual ~OpHandle() {}
 
-  virtual void Run() { PADDLE_THROW("Not implemented"); }
-  virtual void Wait(platform::DeviceContext *waited_dev) {}
+  virtual void Run() = 0;
+  virtual void Wait(platform::DeviceContext *waited_dev) = 0;
 };
 
 struct ComputationOpHandle : public OpHandle {
@@ -382,7 +382,6 @@ struct NCCLAllReduceOpHandle : public OpHandle {
       }
 
       auto &var_name = static_cast<VarHandle *>(this->inputs_[0])->name_;
-      VLOG(3) << "Invoke NCCL AllReduce";
       int dtype = -1;
       size_t numel = 0;
 
@@ -848,7 +847,8 @@ void ParallelExecutor::RunOp(
       LOG(FATAL) << "Unknown exception catched";
     }
   };
-  member_->pool_.enqueue(op_run);
+  op_run();
+  //  member_->pool_.enqueue(op_run);
 }
 }  // namespace framework
 }  // namespace paddle