def kill(signal)
      Process.kill(signal.to_s, pid) if pid && @self_started
      @killed = true
    rescue Errno::ESRCH => e
      log "Can't kill #{pid}: #{e}"
    end
def kill(signal)
      Process.kill(signal.to_s, pid) if pid && @self_started
      @killed = true
    rescue Errno::ESRCH => e
      log "Can't kill #{pid}: #{e}"
    end
Public: Shut this worker down.