Method Send

cpp/src/arrow/util/io_util.cc:1311–1319

XXX return StatusCode from here?

  // XXX return StatusCode from here?
  void Send(uint64_t payload) override {
    if (signal_safe_) {
      int saved_errno = errno;
      DoSend(payload);
      errno = saved_errno;
    } else {
      DoSend(payload);
    }
  }

  Status Shutdown() override {
    please_shutdown_.store(true);