[PATCH 8/8] score: Replace watchdog handler implementation

Joel Sherrill joel at rtems.org
Fri Mar 4 19:12:55 UTC 2016


On Fri, Mar 4, 2016 at 12:25 AM, Sebastian Huber <
sebastian.huber at embedded-brains.de> wrote:

>
>
> On 03/03/16 23:44, Joel Sherrill wrote:
>
>>
>>     >
>>     > "be placed on Red-Black Trees for set management." copy-pasted
>>     comment
>>     > should be Chains?
>>
>>     Thanks, for spotting this.
>>
>>     >
>>     > "watchdog is scheduled and a black node". ditto, black should be red
>>     > for the second one.
>>
>>     Oh, yes.
>>
>>     >
>>     > _Watchdog_Ticks_from_seconds(): why is ticks = seconds<<30 the right
>>     > thing to do? Same for _Watchdog_Ticks_from_timespec(). I am missing
>>     > some assumption here, I guess. It might improve readability to
>>     provide
>>     > a helper function for this.
>>
>>     Ok, sorry for the magic numbers.  2**30 == 1073741824 enough to
>>     cope with 1e9 nanoseconds.  So, we have 2**34 seconds available,
>>     leading to a year 2514 problem.
>>
>>
>> That's pretty close to the 2^64 nanosecond limit as I recall. So
>> reasonable but
>> I suppose that should be very explicit somewhere in a comment.
>>
>> Funny, before there was a wiki, we had a FAQ document which had a section
>> on
>> date/time overflow issues. We probably need a section in the users manual
>> with
>> the current truth on this:
>>
>>
>> https://docs.rtems.org/releases/rtemsdocs-4.6.4/share/rtems/html/FAQ/FAQ00100.html
>>
>> We have multiple date/time and interval representations in the score,
>> classic and
>> POSIX APIs. It would be good to capture them again.
>>
>
> Yes, this is on my TODO list along with the year 2038 problem.
>
>
I thought we had discussed on newlib just changing time_t to 64 bits for
RTEMS.
But clearly the code still has it as a long.

That seems to be the most straightforward solution.

--joel


> --
> Sebastian Huber, embedded brains GmbH
>
> Address : Dornierstr. 4, D-82178 Puchheim, Germany
> Phone   : +49 89 189 47 41-16
> Fax     : +49 89 189 47 41-09
> E-Mail  : sebastian.huber at embedded-brains.de
> PGP     : Public key available on request.
>
> Diese Nachricht ist keine geschäftliche Mitteilung im Sinne des EHUG.
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.rtems.org/pipermail/devel/attachments/20160304/ed6cc3e2/attachment-0002.html>


More information about the devel mailing list