thread_pool_.reset();
  mutex_lock l(mu_);
  return status_;
}

void QueueRunner::UpdateStatus(const Status& status) {
  {
    mutex_lock l(mu_);
    if (!status_.ok() || status.ok() || IsQueueClosed(status)) {
      return;
    }
    status_ = status;
  }
  if (coord_) {
    coord_->ReportStatus(status);
  }
  mutex_lock l(cb_mu_);
  for (auto& cb : callbacks_) {
    cb(status);
  }