Hi Sumit,
I believe the code is correct. The first call of the timer triggers it after
a random duration. This is to keep the durations different for different
nodes. But once it is triggered you repeatedly call the single shot timer
with a deterministic duration. This deterministic duration will maintain
the original randomness throughout (assuming clock drifts etc are absent).
Hope this helps,
Kannan.
Quoting Sumit Gupta <[EMAIL PROTECTED]>:
> Hi,
>
> I am trying to understand the code of SurgeTelos application. Now this
> application is using Component MultiHopLQI (located in
> ..tinyos-1.x/tos/lib/MultiHopLQI/)
> for routing. In this component developer use Timer component for
> triggering
> the collection of data and sending it to base station.
>
> Now I am bit confused. In this they are using argument TIMER_ONE_SHOT for
> Timer, which I believe is wrong because it should be TIMER_REPEAT to
> repeat
> the process of sending data to base station over and over again. If not
> then
> how it has been implemented. Please explain if you understand what I am
> missing out here.
>
> They used it at two places. First when application initialized, which
> make
> sense to me as they are awaking each node at random time, but I am not
> sure
> why they are using again at second time with TIMER_ONE_SHOT parameter.
> Please give a look and help me understanding. Is it a typo?
>
> // First time when timer will initialized
> command result_t StdControl.start() {
> gLastHeard = 0;
> call Timer.start(TIMER_ONE_SHOT,
> call Random.rand() % (1024 * gUpdateInterval));
> return SUCCESS;
> }
>
> //Second time when timer will fire
> event result_t Timer.fired() {
> post TimerTask();
> call Timer.start(TIMER_ONE_SHOT, 1024 * gUpdateInterval + 1);
> return SUCCESS;
> }
>
> Is it because Timer is being started again from Timer.fired function? I
> just
> want to make sure that I am understanding it in a right way. Please
> advice.
>
> Regards,
> Sumit Gupta
>
_______________________________________________
Tinyos-help mailing list
Tinyos-help@Millennium.Berkeley.EDU
https://mail.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
