[ntp:questions] Start of new GPS 1024 week epoch

Michael Tatarinov kukabu at gmail.com
Fri Aug 23 12:31:45 UTC 2013

2013/8/23, Martin Burnicki <martin.burnicki at meinberg.de>:
> David Taylor wrote:
>> On 20/08/2013 13:25, Martin Burnicki wrote:
>> []
>>> There were 2 fields in the SHM segment which were previously unused and
>>> are now used to take the nanoseconds from the refclock and from the
>>> system time.
>>> Thus programs like gpsd can now write the nanoseconds in addition to the
>>> microseconds. If there's an old version of ntpd running then it just
>>> evaluates the microseconds, but new versions (ntp-dev for now) check if
>>> the nanoseconds fields are filled up and use them if this is the case.
>>> Thus an old ntpd works with a new gpsd, and a new ntpd works with an old
>>> gpsd. See:
>>> Bug 1232 - nanosecond support in SHM driver
>>> https://bugs.ntp.org/show_bug.cgi?id=1232
>>> Martin
>> Is SHM supported on Windows?  I know that it /could/ be as the
>> mechanisms exist within the OS, but /is/ it?
> I'm afraid it is not.
> A quick look into the config file for Windows for the current ntp-dev
> version shows that support for the SHM driver is commented out.
> I have also worked with shared memory under Windwos for the driver
> software for our PCI cards, Windows uses completely other API calls for
> the shared memory support, and thus "someone" needed to port the SHM
> driver in ntpd to Windows first.

Yes, SHM driver is commented out but look at refclock_shm.c. The shm
refclock supports Windows and it's added over 15 year ago (according
to the BitKeeper).
ps. I don't know if it works?

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