// define callback
void *on_read(int sock, short which, void *args) {}

// main 
include "levent/epoll.h"
Epoll ep(1024);
struct event_s ev[request_num];
int i = 0;
while(i < request_num) {
    // add event
    ep.set(ev + i, fd, EV_READ, on_read, (void *)this);
    ep.add(ev + i);
    i++;
}
// dispatch
ep.dispatch(max_timeout);