[fpc-devel] NowUTC in the RTL

Sven Barth pascaldragon at googlemail.com
Fri Dec 9 16:10:54 CET 2011


Am 09.12.2011 15:37, schrieb zeljko:
> On Friday 09 of December 2011 14:52:56 Sven Barth wrote:
>
>  > Am 09.12.2011 13:30, schrieb Michael Schnell:
>
>  > > On 12/09/2011 01:17 PM, Felipe Monteiro de Carvalho wrote:
>
>  > >> I would like to define it like this: "FPGetTickCount returns the
>
>  > >> amount of ticks since an unspecified initial time. This initial time
>
>  > >> is unknown, but is fixed for the entire duration of the application.
>
>  > >> Ticks are time intervals and all of them have the same duration, but
>
>  > >> their exact meaning in terms of real world units like milliseconds is
>
>  > >> unspecified. FPGetTickCount is not affected by timezones and also not
>
>  > >> by the user changing the system clock." So it matches
>
>  > >> Windows.GetTickCount well but still is flexible enough to be
>
>  > >> implemented in other platforms.
>
>  > >
>
>  > > What if the PC is polling a time server or similar ? IMHO
> FPGetTickCount
>
>  > > should not be affected by such interference. This rules out using OS
>
>  > > time API calls.
>
>  >
>
>  > 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...
>
>
> No, MONOTONIC_RAW is introduced in 2.6.26 afair, so it won't run on
> older kernels.

My comment was less for which timer type we should support, but more to 
have a argument for what Felipe said.

Regards,
Sven




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