libevent(一)定时器Demo

开始研究libevent，使用的版本是2.0.22。 

 

实现一个定时器：每2秒执行一次printf。

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <event2/event.h>
#include <event2/event_struct.h>
#include <time.h>

int event_is_persistent;

static void timeout_cb(int fd, short event, void *arg)
{
    printf("run timeout_cb\n");
    
    if (!event_is_persistent) {
        struct event *timeout = (struct event*)arg;
        struct timeval tv;
        tv.tv_sec = 2;
        tv.tv_usec = 0;
        event_add(timeout, &tv);
    }
}

int main(int argc, char **argv)
{
    int flags;
    
    if (argc == 2 && !strcmp(argv[1], "-p")) {
        event_is_persistent = 1;
        flags = EV_PERSIST;
    } else {
        event_is_persistent = 0;
        flags = 0;
    }
    
    /* Initalize the event library */
    struct event_base *base = event_base_new();
    
    /* Initalize one event */
    struct event timeout;
    event_assign(&timeout, base, -1, flags, timeout_cb, (void*) &timeout);
    
    struct timeval tv;
    tv.tv_sec = 2;
    tv.tv_usec = 0;
    event_add(&timeout, &tv);
    
    event_base_dispatch(base);
    
    return (0);
}

 

参考资料:

libevent分析 - sparkliang的专栏 - 博客频道 - CSDN.NET

Libevent源码分析 - luotuo44的专栏 - 博客频道 - CSDN.NET