[fpc-devel] NowUTC in the RTL

[Henry Vermaak]

On 09/12/11 15:15, Sven Barth wrote:
> Am 09.12.2011 15:22, schrieb Michael Schnell:
>> On 12/09/2011 02:52 PM, Sven Barth wrote:
>>>
>>> The description of Felipe mathes Windows' GetTickCount (number of
>>> milliseconds since system start) and Linux' MONOTONIC_RAW time (or
>>> however it is called exactly). So I don't see why this should rule out
>>> OS time API calls...
>>
>> He writes: " Ticks are time intervals and all of them have the same
>> duration "
>>
>> So the counting is not allowed to stop or to jump forward in case a time
>> server access by daemon changing the system time is not allowed to
>> interfere in any way.
>>
>> So I suppose "GetTickCount (number of milliseconds since system start)"
>> would be OK, but MONOTONIC_RAW time does not _sound_ correct.
>
> I haven't found an entry for "MONOTONIC_RAW" (my system's manpage has
> one, but I'm currently at work), but for MONOTONIC:
>
> CLOCK_MONOTONIC
> Clock that cannot be set and represents monotonic time since some
> unspecified starting point.
>
> So even if a deamon plays around with the time the MONOTONIC clock
> should not be affected. That's the basic idea of the MONOTONIC clocks.

MONOTONIC can still be affected by NTP, MONOTONIC_RAW can't.

Henry