Re: [notes about] What's going on... ?

On Fri, 23 May 2003 [email protected] wrote:

[... genom, execution engine ...]
> If you remember how GenoM works, we are currently able to parse the .gen
> file in order to generate the execution engine. This is a rather empty
> shell as of now, but it should be able to execute something very soon.

We have also been discussing on and off about what exactly should be
the responsibility of the execution engine. We arrive at three
different aspects:
- logic control: i.e., some outputs are Boolean functions of some
  inputs. This is the basic "PLC" functionality. I don't know where
  you would put such kind of logic in the Genom framework.
- sequencing control, i.e., one activity (or set of activities) must
  be finished before another one can start. This is "FSM/Petri" net
  functionality. I guess this is a core functionality of the execution
  engine.
- configuration control, i.e., make sure that an application can only
  start if all components in the application are properly installed
  and configured.
Maybe event handling is also part of the execution engine's
responsibilities...

So, even if you don't have anything working, I would be very
interested in discussing at this conceptual level.

[...]
> We have several independant libraries:
[...]
> - a task abstraction library on top of the posix interface which
> implements threads, semaphores, timers and shared memory. It is
> compatible with the VxWorks API and we use it with our execution engine.
So, this means (implicitly) that you let the execution engine use
"threads" as its basic elements. And what does it do with these basic
elements? Scheduling, I guess?  If so, that means that you only see
the above-mentioned "sequencing control" as part of the execution
engine? Not really a problem for me, but then we have to define
appropriate names for the others stuff (PLC, configuration control).

> - the execution engine itself, used by genom (here you could use
> yours). Almost empty as of now.
What do you expect to be in there? Something that looks like an OS
scheduler?

[...]
> And as you already know we also have released GDHE (desing of graphical
> interfaces). But this is a bit out of the scope of this mail and we'll
> have the opportunity to talk about this on june the 20th.
> 
I'm very interested in discussing the coupling between both things: a
GUI definitely needs some execution engine, especially of complex
systems such as sensor-based robots.

Good luck with the implementation :-)!

Herman Bruyninckx

-- 
  K.U.Leuven, Mechanical Engineering, Robotics Research Group
<http://people.mech.kuleuven.ac.be/~bruyninc> Tel: +32 16 322480