require "thread"
puts "ProAndCon"
  
queue = Queue.new    #用隊列Queue實現線程同步 
  
producer = Thread.new do
    10.times do |i| 
        sleep rand(i) # 讓線程睡眠一段時間 
        queue i 
        puts "#{i} produced"
    end
end
  
consumer = Thread.new do
    10.times do |i| 
        value = queue.pop 
        sleep rand(i/2) 
        puts "consumed #{value}"
    end
end
  
consumer.join  #等待consumer線程的輸出完成再關閉此進程

ProAndCon
produced
produced
consumed 0
produced
produced
consumed 1
consumed 2
consumed 3
produced
consumed 4
produced
consumed 5