https://www.dzliving.com/2019/03/26/gcdasyncsocket-%E7%9A%84%E5%B0%81%E8%A3%85%E4%B8%8E%E4%BD%BF%E7%94%A8/
https://blog.csdn.net/piratest/article/details/51684353
https://www.tpyyes.com/a/object-c_ios/2017/1113/375.html
https://cherishjoyby.github.io/2017/06/07/iOS%E5%BC%80%E5%8F%91%E4%B9%8BCocoaAsyncSocket%E4%BD%BF%E7%94%A8/
https://github.com/CainLuo/iOS-NetWork