Method StartLoadThread

oneflow/user/data/data_reader.h:57–62

 protected:
  void StartLoadThread() {
    if (load_thrd_.joinable()) { return; }
    load_thrd_ = std::thread([this] {
      while (!is_closed_.load() && LoadBatch()) {}
    });
  }

  std::unique_ptr<Dataset<LoadTarget>> loader_;
  std::unique_ptr<Parser<LoadTarget>> parser_;