Re: [Xenomai-core] Monotonic, realtime, and other timers

[Philippe Gerum <rpm@xenomai.org>]

On Mon, 2007-06-25 at 08:12 +0200, Jan Kiszka wrote:
> Ok, I think it's time to summarise some results of this thread:
> 
>  - xntimers will be of three kinds: real-time absolute, monotonic
>    absolute, and monotonic relative ones (ie. all POSIX). I'm currently
>    in favour of passing this property on timer start and not pushing
>    parts or more of it into timer init.

I will probably experiment this change in the course of x3-devel anyway,
we'll see what we get from it then.

> 
>  - XNTBISOL will be introduced, a flag that, if set, declares a time
>    base being isolated from the master base (and associates). In my
>    understanding, this flag should be passed to xntbase_alloc and should
>    also leave the wallclock offset initially untouched again.
> 
>  - On xntbase_adjust_time, first define the set of affected time bases:
>    if XNTBISOL is set, only touch the passed base, if it is not set,
>    change all bases in the system that have it cleared as well. For this
>    set of time bases, modify the offset and adjust all running real-time
>    timers.
> 
>  - Make all legacy RTOS skins isolated by default again, but offer a
>    runtime or compile-time switch to add them individually to the gang
>    of synchronised time bases (i.e. POSIX, native, RTDM).
> 
> Did I get it correctly?
> 

Looks good. Regarding the monotonic support, I tend to agree with you:
let's avoid conversions especially if doing so is cheap
implementation-wise.

> Jan
> 
-- 
Philippe.