headthread=null
ReentrantReadWriteLock
node[singnal]thread=线程A
FIFO
firstWaiterthread=线程A
tail[exulsive]thread=线程C
CyclicBarrier
node[singnal]thread=线程B
通知加入FIFO
ReentrantReadWriteLock示例，其中读锁是共享锁，当读锁线程拥有锁，通过setHeadAndPropagate会唤醒下个是SHARED状态的节点，b style=\"\
CyclicBarrier cyclicBarrier = new CyclicBarrier(3 );
tail[singnal]thread=线程C
CountDownLatch
node[shared]thread=线程B
node[shared]thread=线程A
tail[singnal]thread=线程B
node[singnal]thread=线程C
lastWaiterthread=线程B
condition
