14장

조건 큐(condition queue)가 나오는데 왜 ‘큐’일까 ?

https://stackoverflow.com/questions/65117449/why-is-condition-variable-also-called-condition-queue-if-it-is-not-implemented-a

https://stackoverflow.com/questions/40436988/wait-notify-which-thread-first-unlock

// AbstractQueuedSynchronizer 먼가... node가...
public final void signal() {
            ConditionNode first = firstWaiter;
            if (!isHeldExclusively())
                throw new IllegalMonitorStateException();
            if (first != null)
                doSignal(first, false);
        }

15장

CAS!!! compare-and-swap!!

낙관적인 락 ????

이것은 가시성을 어떻게 해결해주는건가 ???