Re: [Xenomai-help] Get current wallclock time from RT task

[Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org>]

On 02/03/2012 09:07 PM, Patrick Doyle wrote:
> What is the easiest way to determine the current wallclock time from
> within an RT task?
> 
> I see that I can call rt_timer_inquire() and get back an RT_TIMER_INFO
> structure containing an RTIME type field labeled "date" and a very
> promising comment "Current wallclock time".
> 
> But how do I convert that to e.g. something I could pass to ctime() to
> get something reasonably close to the current wallclock time?

You need to divide it by one billion. But for the result to be
reasonably accurate, you should either:
- compile xenomai as module
- or having synchronized xenomai clock with linux clock at some earlier
point in time by calling timer_settime(CLOCK_REALTIME) (from posix skin).

If your architecture supports it you may also use
clock_gettime(CLOCK_HOST_REALTIME) then you will get a result with very
good accuracy possibly without even a syscall.

-- 
                                                                Gilles.