epoll.c

#include <stdio.h>
#include <sys/epoll.h>

void start_epoll(int fd)
{
    int efd,ret;
    struct epoll_event ev,events;
    int buf;

    efd = epoll_create(1);

    ev.events = EPOLLIN | EPOLLET ;
    ev.data.fd = fd;

    epoll_ctl(efd,EPOLL_CTL_ADD,fd,&ev);

    printf("start to epoll wait...\n");
    while(1){
        ret = epoll_wait(efd, &events, 1, -1);
        /* events is overwritten by epoll_wait, and have ev.data.fd */
        read(events.data.fd, &buf, sizeof(int));
        printf("[%s] ret %d cnt %d \n",__FUNCTION__,ret,buf);
    }
}

main()
{
    int fd[2];
    int cnt = 0;

    pipe(fd);

    if ( fork() == 0 ){
        int rfd = fd[0];
        start_epoll(rfd);
    }

    while(1){
        sleep(1);
        write(fd[1],&cnt,sizeof(int));
        cnt++;
    }

}