Thanks Jonas. I fixed the code like you suggested, using
event_base_loop(global_event_base, 0) and evtimer_add(dummy_event,
&five_seconds). Now the dummy_callback() is indeed called, but the
event_base_loop() exited with a failed status, as show below:
***entering main()
***entering EventLoop()
***dummy_event=0x60e690
***in dummy_callback()
event_base_loop() failed
***exiting EventLoop()
***exiting main()
Any idea what might be wrong? Following is the current code:
#include <stdlib.h>
#include <stdio.h>
#include "event2/event.h"
struct event_base *global_event_base;
static void dummy_callback(evutil_socket_t fd, short what, void *arg)
{
printf("***in dummy_callback()\n");
}
static void* EventLoop(void *arg)
{
printf("***entering EventLoop()\n");
global_event_base = event_base_new();
if (!global_event_base) {
printf("event_base_new() failed\n");
exit (-1);
}
struct timeval five_seconds = {5,0};
struct event *dummy_event =
evtimer_new(global_event_base, dummy_callback, arg);
printf("***dummy_event=%p\n", dummy_event);
evtimer_add(dummy_event, &five_seconds);
// int ret = event_base_loop(global_event_base, EVLOOP_NONBLOCK);
int ret = event_base_loop(global_event_base, 0);
if (ret!=0)
printf("event_base_loop() failed\n");
printf("***exiting EventLoop()\n");
return NULL;
}
int main()
{
printf("***entering main()\n");
EventLoop(NULL);
printf("***exiting main()\n");
fflush(stdout);
return 0;
}
On Fri, Jan 29, 2010 at 2:45 AM, Jonas Romfelt <[email protected]> wrote:
> Hi,
>
> if I'm not mistaken your call to event_base_loop() will not wait for
> the timer event you added to expire beacuse the EVLOOP_NONBLOCK flag
> is set. Simply because your 5 seconds timer has not yet expired when
> the event_base_loop() is called.
>
> Try: event_base_loop(global_event_base, 0) or
> event_base_loop(global_event_base, EVLOOP_ONCE) if you want to exit
> the loop after the timer expired.
>
> Also, you could change event_add(dummy_event, &five_seconds) to
> evtimer_add(dummy_event, &five_seconds). Event though it's just a
> macro you never know when something under the API may change...
>
> cheers,
> Jonas Romfelt
>
>
>
> 2010/1/29 Donghua Xu <[email protected]>
> >
> > Hi, I just wrote a simple program trying to use the timeout event in
> libevent 2.0.3-alpha. The source code is at the end of the email. I'm
> expecting to see a print out of "***in dummy_callback()", but this line does
> not show up at all. What I am seeing is only:
> >
> > ***entering main()
> > ***entering EventLoop()
> > ***dummy_event=0x60e690
> > ***exiting EventLoop()
> > ***exiting main()
> >
> > What am I doing wrong in the following source code? A lot of thanks in
> advance...
> >
> >
> >
> > #include <stdlib.h>
> > #include <stdio.h>
> > #include "event2/event.h"
> >
> > struct event_base *global_event_base;
> >
> > static void dummy_callback(evutil_socket_t fd, short what, void *arg)
> > {
> > printf("***in dummy_callback()\n");
> > }
> >
> > static void* EventLoop(void *arg)
> > {
> > printf("***entering EventLoop()\n");
> > global_event_base = event_base_new();
> > if (!global_event_base) {
> > printf("event_base_new() failed\n");
> > exit (-1);
> > }
> >
> > struct timeval five_seconds = {5,0};
> > struct event *dummy_event =
> > evtimer_new(global_event_base, dummy_callback, arg);
> >
> > printf("***dummy_event=%p\n", dummy_event);
> >
> > event_add(dummy_event, &five_seconds);
> >
> > int ret = event_base_loop(global_event_base, EVLOOP_NONBLOCK);
> > if (ret!=0)
> > printf("event_base_loop() failed\n");
> >
> >
> > printf("***exiting EventLoop()\n");
> > return NULL;
> > }
> >
> > int main()
> > {
> > printf("***entering main()\n");
> > EventLoop(NULL);
> > printf("***exiting main()\n");
> > fflush(stdout);
> > return 0;
> > }
> >
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