Method fetch_rows_lock

be/src/service/client-request-state.h:315–315

  }
  std::mutex* lock() { return &lock_; }
  std::mutex* fetch_rows_lock() { return &fetch_rows_lock_; }

  /// ExecState is stored using an AtomicEnum, so reads do not require holding lock_.
  ExecState exec_state() const { return exec_state_.Load(); }