orders.rb

#!/usr/bin/ruby

pid = fork do
  def find_order
    # check for order and return one if found
  end

  monitor = Fiber.new do
    # Keep checking
    loop do
      # check for new orders in a loop
      order = find_order

      # When one is found
      if order.found?
        # Pass the order to handle Fiber
        handle.resume order
      end

      # Wait 5 minutes
      sleep 60*5
    end
  end

  handle = Fiber.new do |order|
    # handle it here... then resume monitoring
    monitor.resume
  end
end

Process.detach(pid)