Hi, I had forgotten about this.
I went back to the drawing board and had almost completed a new version.  Looking at the Java barrier shows how one can go overboard with stuff.  My though with the barrier is to provide a simple synchronization primitive that works well for example in the unittests, without trying too hard to over design it in terms of failure modes.

Anyway, I´ll get my act together.  Same with RWLock, that is almost ready