[CHY872]

I've been coding in Java for a bit longer than that, and in my memory it's always been known that ReentrantLock is _faster_, but synchronized has better language level support (as in, the language won't let you forget to unlock, whereas with locks you need to remember your finally statement). And then, unlike ReentrantLock, synchronized uses no extra memory, which is good for things that end up being uncontended, and then in both cases, the performance doesn't matter if the lock is uncontended, which most of mine were.

There of course are things like ErrorProne that statically check that you unlocked your lock, but there's still bugs possible.