That doesn't seem that bad to me. It's an explicit, unambiguous recommendation, one that even be recognized by static analysis. It's not much worse than an API

That doesn't seem that bad to me. It's an explicit, unambiguous recommendation, one that even be recognized by static analysis. It's not much worse than an API that requires that you call some particular method--the only part that's bad is that you can fail to notice the problem because the code will usually work. What I worry about are things that can't be easily caught. I trust myself to write embarrassingly parallel code, and I've written some code that has real risks of deadlock. But shared data structures that have complex locking schemes still scare me.