https://www.cnblogs.com/zhaoyanjun/tag/IO%E6%B5%81/
https://blog.csdn.net/qq_41061437/article/details/81740680
https://blog.csdn.net/a1203991686/article/details/81565432
https://www.cnblogs.com/oubo/archive/2012/01/06/2394638.html
http://www.cnblogs.com/hopeyes/p/9736642.html
https://blog.csdn.net/qq_36962144/article/details/79815457 （重点在源码分析）