Internally all calculations are performed in nanoseconds, so there's no
drift.
Michael.
S?bastien GAUME ([EMAIL PROTECTED]) wrote:
> Hello,
>
> I have a question about the "gethrtime" function.
>
> This function, as said in the man pages, returns the time in
> nanoseconds. Which means that it converts the clock ticks into
> nanoseconds. As the clock period is unfortunately not an integer
> multiple of nanoseconds, the conversion will entail a rounding or
> truncation on the last digit.
>
> Thus, when you ask a task to be periodic, you give the period in
> nanoseconds and I suppose this value is converted into clock ticks,
> which entails a rouding. Suppose a task is periodic, running in the
> oneshot mode. Periodically, the next wake up date is calculated in clock
> units. Because the period in clock unit is not equal to the period in
> nanoseconds, a drift should be seen, especially after a large number of
> periods.
>
> In fact, after having done this test, I did not see such a drift. Do not
> think I am disapointed, I'm not ! I would like to know wether I am wrong
> in my assumptions or not, and if not, how the gethrtime function manages
> not to create a drift.
>
> Thank you
>
> Sebastien
>
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