libevent::事件::定时器

#include <cstdio>

#include <errno.h>

#include <sys/types.h>

#include <event.h>

#include <event2/event.h>

#include <event2/event_struct.h>

#include <event2/event-config.h>

#include <event2/util.h>

int lasttime;

static void

timeout_cb(int fd, short event, void *arg)

{

    struct timeval tv;

    struct event *timeout = (struct event *)(arg);

    int newtime = time(NULL);

    printf("%s: called at %d: %d\n", "timeout_cb", newtime, newtime - lasttime);

    lasttime = newtime;

    evutil_timerclear(&tv);

    tv.tv_sec = 2;

    // 重新添加定时事件（定时事件触发后默认自动删除）  

    event_add(timeout, &tv);

}

int main(int argc, char **argv)

{

    struct event timeout;

    struct timeval tv;

    //初始化event环境

    event_init();

    //设置事件

    evtimer_set(&timeout, timeout_cb, &timeout);

    evutil_timerclear(&tv);

    tv.tv_sec = 2;    //2s

    //注册事件

    event_add(&timeout, &tv);

    lasttime = time(NULL);

    //等待,分发,处理事件

    event_dispatch();

    return (0);

}