同步（Synchronous） 异步 (Asynchronous) 阻塞 (Blocking) 非阻塞 (Nonblocking) 同步（Synchronous）异步 (Asynchronous)阻塞 (Blocking)非阻塞 (Nonblocking)Reference [知乎] 怎样理解阻塞非阻塞与同步异步的区别