[kepler-dev] SDF/PN question

[Bertram Ludaescher]

Hi:

Efrat and I are just having an interesting discussion on how the
display actor (and similarly, a new "logging actor") work/should work.

Assume you have a display actor to which two parallel actors are
connected:
       ________
[A1]--|DISPLAY|
[A2]--|DISPLAY|
       --------

In an SDF domain, it seems that input channels are tried in the order
the corresponding actors where connected -- let's say A1 first, then
A2.

If the token arrives first on A2 (even a week earlier ;-) then nothing 
would be displayed until also A1 arrives (because DISPLAY cannot fire
until A1 is ready).

Conversely, if we change this to PN, the behaviour would/should change
(I think), right? 

If A2 was arriving first, would the firing rule of DISPLAY (under PN
semantics) be so that A2's output would be written first?

It seems that PN is the director of choice then for most of the
example workflows we've encountered -- in this case for logging the
workflow execution.

Who wants to make a stand for SDF (other than the nice animation
feature) or a version between SDF and PN (dynamic dataflow?) 

Or would another director (Efrat just mentioned DE) be more
appropriate?

Bertram