What is the diagram option "Reaction level" supposed to do?

[cmnrd]

I stumbled across the diagram option "Reaction level" today. However, it does not seem to do anything. I tested this on various programs, but the diagrams did not change when checking or unchecking this option.

[a-sr]

@edwardalee added this option, he can probably explain best what it does.
As far as I know, it shows levels that indicate orderings due to dependencies and exposes potential for parallelization of reactions.
What I don't know is how it works. I guess the option will only display something if there was some kind of compilation producing the necessary information.

[edwardalee]

I suspect this no longer works because of this change by @petervdonovan in ReactionInstance.java:

    // Force calculation of levels if it has not been done.
FIXME
    // FIXME: Comment out this as I think it is redundant.
    //  If it is NOT redundant then deadline propagation is not correct
    // parent.assignLevels();

Testing this hypothesis, however, seems rather time consuming now that everything is in separate repos. I don't have time to check this.

[edwardalee]

That said, maybe we don't really need this feature? Perhaps easiest to just remove it.

[cmnrd]

I was also wondering if it is worth repairing. I'll open a PR removing this synthesis option.