操作系统 - epoll中的ET和LT

参考

https://www.quora.com/What-is-meant-by-edge-triggering-and-level-triggering
http://man7.org/linux/man-pages/man7/epoll.7.html
https://www.quora.com/What-is-the-difference-between-the-edge-trigger-and-the-level-trigger-in-epoll

为啥叫LT和ET

因为这两个是引用电路中的水平触发和边缘触发这两个概念。