[Libevent-users] Timerout procedure can't enter twice

[Michael <michaelxmail@xxxxxxxxx>]

Hi ,

I'm using libevent to create timer procedure.

The attached program will call the timeout function at the first time. 

But it won't call the timeout function after I rewrite the timer.


Attached please find the test code. 

Is there anything I'm missing ?

Thanks!

Michael
/*
 * XXX This sample code was once meant to show how to use the basic Libevent
 * interfaces, but it never worked on non-Unix platforms, and some of the
 * interfaces have changed since it was first written.  It should probably
 * be removed or replaced with something better.
 *
 * Compile with:
 * cc -I/usr/local/include -o time-test time-test.c -L/usr/local/lib -levent
 */

#include <sys/types.h>

#include <event2/event-config.h>

#include <sys/stat.h>
#ifndef WIN32
#include <sys/queue.h>
#endif
#include <time.h>
#include <unistd.h>
#ifdef _EVENT_HAVE_SYS_TIME_H
#include <sys/time.h>
#endif
#include <fcntl.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>

#include <event2/event.h>
#include <event2/event_struct.h>
#include <event2/util.h>

struct timeval lasttime, lasttime2, lasttime3, lasttime4, lasttime5;

int event_is_persistent;

static void
timeout_cb(evutil_socket_t fd, short event, void *arg)
{
	struct timeval newtime, difference;
	struct event *timeout = arg;
	double elapsed;

	evutil_gettimeofday(&newtime, NULL);
	evutil_timersub(&newtime, &lasttime, &difference);
	elapsed = difference.tv_sec +
	    (difference.tv_usec / 1.0e6);

	printf("timeout_cb called at %d: %.3f seconds elapsed.\n",
	    (int)newtime.tv_sec, elapsed);
	lasttime = newtime;

}

void main()
{
	struct event *timeout;
	struct timeval tv;
	struct event_base *base;
	
	int flags;

    event_is_persistent = 0;
    flags = 0;

	/* Initalize the event library */
	base = event_base_new();

	/* Initalize one event */
	timeout = event_new(base, -1, flags, timeout_cb, (void*) timeout);

	evutil_timerclear(&tv);
    tv.tv_sec=2;
    tv.tv_usec=0;
	event_add(timeout, &tv);
    printf("Timer writed \n");
	
	evutil_gettimeofday(&lasttime, NULL);
	event_base_dispatch(base);

    usleep(5000*1000);

    printf("rewrite timer \n");
    
    timeout = event_new(base, -1, flags, timeout_cb, (void*) timeout);
    evutil_timerclear(&tv);
    tv.tv_sec=2;
    tv.tv_usec=0;
	event_add(timeout, &tv);
	
    usleep(5000*1000);

	return (0);
}