I agree that it is fishy and I would never use it in practice (the reason for the lack of real code and the disclaimer in the last line of the post) since over the years I've learned that once you start messing around with operation ordering too much, and start requiring non-blocking locks, chances are good the locking strategy is incorrect.

That said, I'm not entirely convinced that it can't be fixed, perhaps by using only a single rename, only that it isn't worth it. Your solution is more elegant in any case.

bluto