[linux-audio-dev] Audio/Midi system - RT prios..

[fons adriaensen]

On Fri, Dec 30, 2005 at 11:54:56AM -0500, Paul Davis wrote:

> you don't know the correct priority to use. i imagine an api along the
> lines of:
> 
> 	jack_create_thread (pthread_t*, void* (thread_function)(void*), 
>                             void* arg, int relative_to_jack);
> 
> the last argument would specify that the thread should run at, above or
> below the jack RT thread(s) by a given amount. typical values would be 
> +1, 0, -1 etc.

- It's fairly easy to find out a JACK client's thread priority - some
  of my apps, e.g. Aeolus do this to set their thread priorities relative
  to it.

- It could be wise to express *all* (including JACK's) priorities relative
  to the maximum. That way things will still work when the kernel developers
  decide to revise their numbering scheme.

- Some apps may want to run as well without linking to libjack, so I'm not
  so sure that this is the right place for a RT-thread creation routine.
  Anyway, unless you want to use capabilities or work around completely
  broken things such as NPTL 0.60, creating a RT thread *is* quite simple.
  If you are using an application framework or toolkit, and it provides
  safe communication between RT and e.g. GUI threads, then it probably 
  will have a call to do it anyway.


Best wishes to all !

-- 
FA