Epollet lessons

In the use of epoll Of ET Pattern . Read a lot of information on the Internet , Some basic concepts ,
for example accept and recive To go back EAGAIN or EWOULDBLOCK Just stop .
problem ：
      Such as EPOLL The author of Davide Libenzi said , If you are right fd Register at the same time EPOLLIN | EPOLLOUT event ,
Even if the send buffer does not change from full to empty , It will also trigger EPOLLOUT event （ Reference link ：http://www.0x61.com/forum/post3712824.html）.

 

stay epoll_wait() Wait until you want to accept the connection , Yes accept（） The function needs to read circularly , Until return EWOULDBLOCK Just stop , Otherwise, when a lot of concurrency comes , It's easy to lose connections