class Puma::Cluster

def stop_workers
  log "- Gracefully shutting down workers..."
  @workers.each { |x| x.term }
  begin
    loop do
      wait_workers
      break if @workers.reject {|w| w.pid.nil?}.empty?
      sleep 0.2
    end
  rescue Interrupt
    log "! Cancelled waiting for workers"
  end
end