[pjmlp]

Although in highly parallel code, the primitives from java.util.concurrent are to be preferred.

I highly advise reading "Java Concurrency in Practice".

Note that future Java primitive classes don't have monitors.

[karmakaze]

Seems like a vague way of saying that locks 'don't scale' or aren't composable, which is certainly the case but straying from the topic of memory models.