On Fri, Sep 30, 2005 at 10:41:13AM -0700, Juan Betty-MGIA2720 wrote:
> Oops, must be the multitasking problem. This should work -
>
> --- snmp_alarm.c.old 2005-09-28 11:03:28.000000000 -0700
> +++ snmp_alarm.c 2005-09-30 09:20:30.000000000 -0700
> @@ -223,6 +223,7 @@
> return NULL;
> }
>
> +static timeval t_last_run_alarms={ 0, 0 };
> void
> run_alarms(void)
> {
> @@ -231,6 +232,16 @@
> unsigned int clientreg;
> struct timeval t_now;
>
> + int timeBackFlag = 0;
> + gettimeofday(&t_now, NULL);
> + if( (t_now.tv_sec < t_last_run_alarms.tv_sec) ||
> + ((t_now.tv_sec == t_last_run_alarms.tv_sec) && (t_now.tv_usec <
> t_last_run_alarms.tv_usec) )
> + ) { // we have a clock going back reset the timers
> + timeBackFlag =1;
> + }
> + t_last_run_alarms.tv_sec = t_now.tv_sec;
> + t_last_run_alarms.tv_usec = t_now.tv_usec;
> +
> /*
> * Loop through everything we have repeatedly looking for the next thing
> to
> * call until all events are finally in the future again.
> @@ -243,13 +254,14 @@
>
> gettimeofday(&t_now, NULL);
>
> - if ((a->t_next.tv_sec < t_now.tv_sec) ||
> + if ( timeBackFlag || (a->t_next.tv_sec < t_now.tv_sec) ||
> ((a->t_next.tv_sec == t_now.tv_sec) &&
> (a->t_next.tv_usec < t_now.tv_usec))) {
> clientreg = a->clientreg;
> DEBUGMSGTL(("snmp_alarm", "run alarm %d\n", clientreg));
> (*(a->thecallback)) (clientreg, a->clientarg);
> DEBUGMSGTL(("snmp_alarm", "alarm %d completed\n", clientreg));
> + timeBackFlag = 0;
>
> if ((a = sa_find_specific(clientreg)) != NULL) {
> a->t_last.tv_sec = t_now.tv_sec;
>
>
Yes - this should fix problem #0, have you thought about #1 and #2 yet as those
are he hard ones?
> Now to the problems with the patch:
>
> 0) It doesn't apply since it is malformed (Chunk 1 and 2 lacks one line each)
> This I am certain is just a cut'n-paste mistake or some such :-)
>
> 1) It might end up running things early if the time went backwards. Now I do
> not say that early is worse than late, I just say that it is't much better
> either.
>
> 2) It handles only one outstanding timeout, if there are two in the queue that
> should happen in the next minute and you set back the clock an hour your
> patch will run the first one and the second one will be delayed.
>
> Now, to run every timeout is also wrong, what is needed is a way to tell
> how big the time warp was and then adjust timeouts that should wait for
> N time units but leave those that should run at a certain time alone.
>
> The size of the timewarp could probably be found using something like
> clock_gettime(CLOCK_MONOTONIC, ...) but that is not a required interface.
> Also note that this could be used to detect forward warps.
>
/MF
-------------------------------------------------------
This SF.Net email is sponsored by:
Power Architecture Resource Center: Free content, downloads, discussions,
and more. http://solutions.newsforge.com/ibmarch.tmpl
_______________________________________________
Net-snmp-coders mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/net-snmp-coders
