AQS之CyclicBarrie

transferForSignal(Node node)

firstWaiter

waitStatus=0thread=thread1

lock.unlock()

唤醒thread0

prev

唤醒后续的节点

加锁

next

lastWaiter

thread2

唤醒thread1

waitStatus=-1thread=null

waitStatus=-2thread=thread0

parties=3

head

条件队列

同步队列转条件队列

LockSupport.park(this)

CAS尝试获取锁成功

nextWaiter

同步队列入队

tail

trip.signalAll()

frist

入队（条件队列)， 阻塞

阻塞thread0

同步队列出队成功

waitStatus=0thread=null

阻塞thread1

真正用到的计数器，用于标记线程数

lock.lock()

LockSupport.unpark(s.thread)

waitStatus=-2thread=thread1

 private void doSignalAll(Node first) {            lastWaiter = firstWaiter = null;            do {                Node next = first.nextWaiter;                first.nextWaiter = null;                transferForSignal(first);                first = next;            } while (first != null);        }

count=1

条件队列出队操纵

waitStatus=-1thread=thread0

thread0

条件等待对列： Condition

冲洗获取锁，执行完业务逻辑，再释放锁

入队成功

AQS: 同步等待队列  获取锁失败时， 入队 阻塞条件等待对列： Condition

count=0

总结：

thread1

释放锁

waitStatus=0thread=thread0

trip.await()

count=2

指定线程数，副本，用于重置

count=3

阻塞线程的唤醒，条件队列的出队