Hi Bob, The long is not necessarily defined as 4 bytes. I have checked the GNU reference manual [1] and it states
> The 32-bit unsigned long int data type can hold integer values in the range > of at least 0 to 4,294,967,295. (Depending on your system, this data type > might be 64-bit, in which case its range is identical to that of the unsigned > long long int data type.) You may also refer to this data type as unsigned > long. So it can be 64bit long. I have tested this on x86_64 Linux and x86_64 Genode on NOVA and in both cases the sizeof(unsigned long) returned 8. So it is a 64 bit integer type. I also tested this by assigning 2^32 which should yield 0 on a 32 bit type but it didn't. Regarding this the overflow is most probably happening at some lower level (I have not checked the exact implementation of the timer). Regards, Johannes [1]: https://www.gnu.org/software/gnu-c-manual/gnu-c-manual.html#Integer-Types Am 18.02.2018 um 20:59 schrieb Bob Stewart: > Johannes, > > Unsigned longs are 4 bytes. Unsigned long longs are 8 bytes. One byte > equals 8 bits. > > Bob Stewart > > > Get Outlook for Android <https://aka.ms/ghei36> > > ------------------------------------------------------------------------ > *From:* Johannes Kliemann <kliem...@componolit.com> > *Sent:* Sunday, February 18, 2018 6:01:36 AM > *To:* Genode OS Framework Mailing List > *Subject:* 32 bit overflow in timer > > Hi all, > > I noticed a 32 bit overflow in the Timer::Connection sleep functions and > triggers. > Calling usleep or trigger_once with an hour (3 600 000 000 us) works but > calling it with two hours (7 200 000 000 us) causes something to > overflow and stop the timer after 2 905 032 704 us which equals 7 200 > 000 000 & (2^32 - 1). > > As far as I have checked this these functions use the unsigned long > which is indeed 64 bit but I think at some point only 32 bit are used. > > Is this intended behaviour? > If so I think it would make sense to give out a warning at least. > > Regards, > Johannes > > ------------------------------------------------------------------------------ > Check out the vibrant tech community on one of the world's most > engaging tech sites, Slashdot.org! http://sdm.link/slashdot > _______________________________________________ > genode-main mailing list > genode-main@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/genode-main > > > ------------------------------------------------------------------------------ > Check out the vibrant tech community on one of the world's most > engaging tech sites, Slashdot.org! http://sdm.link/slashdot > > > > _______________________________________________ > genode-main mailing list > genode-main@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/genode-main > ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ genode-main mailing list genode-main@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/genode-main
