class Protobuf::Rpc::Zmq::Server

def wait_for_shutdown_signal
  loop do
    break if IO.select([@shutdown_r], nil, nil, timeout)
    start_broker unless brokerless?
    reap_dead_workers if reap_dead_workers?
    start_missing_workers
    next unless broadcast_heartbeat?
    if broadcast_busy? && all_workers_busy?
      broadcast_flatline
    else
      broadcast_heartbeat
    end
  end
end