[Xenomai-help] Re: Re: Re: A fairly small rtnet/Xenomai...

["M. Koehrer" <mathias_koehrer@domain.hid>]

Hi Dmitry, 

> 
> > As this is hard to understand, I strongly recommend that there is Xenomai
> support
> > for this! I.e. a Xenomai API that can be called with a (callback-)function
> pointer and
> > a user data pointer.
> > When a (realtime) thread calls this function, the real time thread is
> blocked.
> > The callback function is then called from a safe context and
> > after exit of the callback function the real time thread is resumed.
> 
> I haven't got your idea. Did you get the cause of the problem with fork() ?
Yes, I think I got it (more or less).

However, as a typical user of a OS I do not want to take care of this
very specific things. I want to call an OS-API that is doing the job for me.
I.e. in my example, I want to call an API that allows me to execute whatever
external application without any risk and side effects.
>From the functional point of view I want to use the "system()" call.
When it is not save to call system() directly (due to all the things that have been
discussed), I think it is important to document this (e.g. in the Wiki) _and_ to
provide an easy usable replacement for it, i.e. something like a rt_task_system()
that does all the required things internally for me and behaves on the functional side exactly
like the standard system() does.
The Xenomai Native example is a very good example for a cleanly designed API that
can be easily (and nearly intuitively) used. 
Any workarounds (I call it workaround as the intuitive, straightforward approach is not possible)
that are required to get a problem solved, weakens the whole OS (Xenomai).

Regards

Mathias

-- 
Mathias Koehrer
mathias_koehrer@domain.hid


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