[Tinyos-devel] improving FTSP interface

[Miklos Maroti]

On Thu, Aug 7, 2008 at 7:32 AM, Omprakash Gnawali <gnawali at usc.edu> wrote:
> On Wed, Aug 6, 2008 at 10:22 PM, Miklos Maroti <mmaroti at math.u-szeged.hu> wrote:
>>> It would be nice for FTSP to provide a rollover bit so that the
>>> applications know that the time has wrapped around since the last the
>>> time was read.
>>
>> Why would you want that? In a 32-bit global time you can regard the
>> highest bit as a rollover indicator, whenever that value has changed
>> from 1 to 0 then you have  a rollover.
>
> That bit might change for reasons other than a rollover.

But realize, the 33rd bit (which is what you are asking for) might
change for other reasons as well. How can FTSP detect a rollover
internally? If your timesync is so much messed up that it cannot
distinguish a rollover from a simple 2^31 unit time offset change,
then you should not rely on it in the first place. Trust me, just
watch the 32nd bit, and tell me a concrete scenario when that is not
working.

Miklos