Method ~BackgroundReader

cpp/src/arrow/io/file_benchmark.cc:79–82

  void Join() { worker_->join(); }

  ~BackgroundReader() {
    ABORT_NOT_OK(internal::FileClose(fd_));
    ARROW_CHECK(CloseHandle(event_));
  }

 protected:
  explicit BackgroundReader(int fd) : fd_(fd), total_bytes_(0) {