Good stuff. Regarding atomicfu, I was playing around with it recently and my impression is that it's very fickle. It has some "magic" to it since it's a compiler plugin that converts regular old atomics to AtomicFieldUpdater. Supposedly it'll perform a bit better, but you end up needing to write your code in a very specific way to satisfy the plugin and even then, I ran into some weird exceptions at runtime that I couldn't figure out. So don't kill Stately quite yet. 🙂