Ruby Fibres example

simple.rb

class Engine

  def initialize
    @tick = 0
    @event_count = 0
    @queue = []
    @fibre = Fiber.new do |arg|
      loop do
        @tick += 1
        e = @queue.pop
       	break if e == :stop
        @event_count += 1 if e
        puts "#{@tick} #{@event_count} event:  #{e}"
        Fiber.yield
      end
    end
  end

  def start
    @fibre.resume
  end

  def continue
    @fibre.resume
  end

  def stop
    @queue.unshift(:stop)
  end

  def event
    @queue.unshift(:event)
  end

end

e = Engine.new
e.start      # 1 0
e.event
e.continue   # 2 1 event
e.event
e.continue   # 3 2 event
e.continue   # 4 2
e.continue   # 5 2
e.stop
e.continue
e.continue   # error