利用libevent的timer实现定时器interval

在不怎么了解libevent的情况下，看到timer这个关键字想到可以用来做定时任务，官方资料也不齐全，就从代码里看到了TIMEOUT字样，这么说来应该是支持timeout了，那interval呢，貌似没有发现更好的办法，姑且在timeout里再timeout一次吧，留代码备用。

#include <stdio.h>
#include <stdlib.h>
#include <event2/event.h>

typedef struct {
        struct timeval tv;
        struct event * ev;
} timer_param_t;


void timer_task(int fd, short events, void * ctx) {
        printf("...
");

        timer_param_t * param = (timer_param_t *) ctx;
        evtimer_add(param->ev, &param->tv);
}

int main() {
        struct event_base * base;
        base = event_base_new();
        if(!base) {
                printf("open event base error
");
                return -1;
        }
        timer_param_t * param = calloc(1, sizeof(timer_param_t));
        param->ev = evtimer_new(base, timer_task, param);
        param->tv.tv_sec = 1;
        evtimer_add(param->ev, &param->tv);
        int err = event_base_dispatch(base);
        printf("error = %d
", err);
        return 0;
}

 编译：gcc -o timer timer.c -levent