The JVM provides a lot more flexible concurrency abstractions, but they're now appearing in the standard library instead of hardwired into the language. This le

The JVM provides a lot more flexible concurrency abstractions, but they're now appearing in the standard library instead of hardwired into the language. This lets us extend or reimplement them. (Synchronized blocks/methods are primitive and haven't been deprecated, but they recommend using java.util.concurrent.locks instead.)