Hi guys!

I would intuitively had guessed that Magma has object locks (pessimistic
concurrency) but I can't find it actually. The thing you are asking for
(counters etc that can handle "physical" conflicts that aren't logical)
is in GemStone called "reduced conflict" classes. I remember that it has
rcCounter and rcSet for example with well defined semantics that you can
follow.

regards, Göran