先Mark,后续完成
https://segmentfault.com/a/1190000017255405
http://ifeve.com/volatile/
http://cmsblogs.com/?hmsr=toutiao.io&p=2092&utm_medium=toutiao.io&utm_source=toutiao.io
https://my.oschina.net/u/2288283/blog/656572
https://blog.csdn.net/eff666/article/details/67640648
http://www.importnew.com/23520.html
https://crowhawk.github.io/2018/02/10/volatile/
https://www.cnblogs.com/xrq730/p/7048693.html
https://www.jianshu.com/p/bd68ddf91240
https://blog.itzmn.com/2018/12/14/并发编程-java并发机制的底层实现原理/