0.https://en.wikipedia.org/wiki/Select_%28Unix%29 1.http://linux.die.net/man/2/select 2.http://bbs.youkuaiyun.com/topics/391874748 3.http://lobert.iteye.com/blog/1768502 4.http://www.cnblogs.com/RascallySnake/archive/2013/07/11/3185071.html