ProAndCon 0 produced 1 produced consumed 0 2 produced 3 produced consumed 1 consumed 2 consumed 3 4 produced consumed 4 5 produced consumed 5
转载自：http://www.oschina.net/code/snippet_1045481_33311
Ruby：线程实现经典的生产者消费者问题,布布扣,bubuko.com
原文：http://www.cnblogs.com/hongfei/p/3695310.html