[Rock-dev] Roby v3 / Syskit v2

[Sylvain Joyeux]

This is a status update about upcoming changes in Roby/Syskit, as well

I've done some refactoring work on Roby, mainly to remove the C++
extension, and in particular the really horrible 13-year-old graph
parts that were still implemented in C++. The end goal was to improve
performance (which for the real-world benchmarks I used was a 10 fold
improvement, real-system results coming soon)

Given how deep that stuff was in Roby, I used the opportunity to clean
up a few things that were really really old and really really feeling
old. Given the amount of changes, I decided to call the result Roby 3.
Syskit 2 ended up being the adaptation of the Syskit codebase to the
new graph API and to the other Roby changes.

In principle, at least in our case, Roby 3 / Syskit 2 did NOT require
any change from the bundles. *The* major backward compatibility
breakage comes from the log format, which is not compatible with the
existing format. Given how little time I have, I don't see myself
spending the effort necessary to convert the old to the new.

It *did* require a change in the syskit-transformer plugin, which will
have to be merged at the same time.

The point of this email is a warning, and to let the Syskit users ask
questions / require some tests / extra info before these changes land
on their heads. I won't merge this on master tomorrow, but not in a
year from now either (i.e. one month or two sounds like a decent
timeframe)

Sylvain