How to use epoll and make the handler functions non-blocking?

Question

I know little about epoll , after checking some documents then think it runs like this:

while(true){
    epoll_wait(some_sock_fds);
    foreach(usable_fds){
        handler(one_fd);  <----- this function must be non-blocking ?
    }
}

In the handler function there should be something about network read/write or file operations, I think it should be non-blocking, yes?

How can I write the handler function so that it does not block the main loop?

Answer 1

The io thread should focus on the network tasks. If the socket is blocked, you should handle every socket in a separate thread. One thread per socket.