A DESCRIPTION OF THE PROBLEM :
hi team,
I have a question that signalAll function just transfer nodes that exists in the condition queue to CLH queue. However I found that AQS depeneds on unparkSuccessor to wake up thread one by one.
So , is there a puzzle or misunderstanding to learn that signalAll used to wake up all threads in condition queue.

We usually use Object.notifyAll compared to AQS.signalAll . Most of us think that signalAll will do two things:
1. transfer nodes from condition queue to CLH.
2. wake up those threads corresponded to nodes.

However , I just found one done. Because signalAll use transferForSignal op one by one.

Maybe I lose something or misunderstand signalAll.
Sincerely look forward to receiving else from you.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
1.Setup one breakpoint on System.out.println line in Thread3 run function.
2.Debug Application
3.Use jstack or [get thread dump] in idea's Debug pannel
4.You will find Thead1, Main, Thread2 are all waiting status.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
After completing signalAll() , thread1 and thread2 are Runnable status.
ACTUAL -
thread1 and thread2 are waiting status.

---------- BEGIN SOURCE ----------
Main Class:

public class Application {

   private static ReentrantLock _lock = new ReentrantLock();
   private static Condition _cond = _lock.newCondition();

    public static void main(String[] args) throws InterruptedException {

        Thread thread1 = new Thread(new Thread1(_lock,_cond),"thread1");
        Thread thread2 = new Thread(new Thread2(_lock,_cond),"thread2");
        Thread thread3 = new Thread(new Thread3(_lock,_cond),"thread3");

        thread1.start();
        thread2.start();
        thread3.start();

        thread1.join();
        thread2.join();
        thread3.join();

        System.out.println("main end");

    }

}

public class Thread1 implements Runnable{

    private ReentrantLock _lock;

    private Condition _cond;

    public Thread1(ReentrantLock _lock, Condition _cond) {
        this._lock = _lock;
        this._cond = _cond;
    }

   
    @Override
    public void run() {

        String threadName = Thread.currentThread().getName();
        System.out.println(String.format("%s----,启动",threadName));

        LockSupport.parkNanos(TimeUnit.SECONDS.toNanos(1));

        _lock.lock();

        System.out.println(String.format("%s----,wait前",threadName));

        try {
            _cond.await();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }

        System.out.println(String.format("%s----,wait后,time:%d",threadName,System.currentTimeMillis()));

        _lock.unlock();


    }
}

public class Thread2 implements Runnable{

    private ReentrantLock _lock;

    private Condition _cond;

    public Thread2(ReentrantLock _lock, Condition _cond) {
        this._lock = _lock;
        this._cond = _cond;
    }

  
    @Override
    public void run() {

        String threadName = Thread.currentThread().getName();
        System.out.println(String.format("%s----,启动",threadName));

        LockSupport.parkNanos(TimeUnit.SECONDS.toNanos(2));

        _lock.lock();

        System.out.println(String.format("%s----,wait前",threadName));

        try {
            _cond.await();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }

        System.out.println(String.format("%s----,wait后,time:%d",threadName,System.currentTimeMillis()));

        _lock.unlock();


    }
}

public class Thread3 implements Runnable{


    private ReentrantLock _lock;

    private Condition _cond;

    public Thread3(ReentrantLock _lock, Condition _cond) {
        this._lock = _lock;
        this._cond = _cond;
    }



  
    @Override
    public void run() {

        String threadName = Thread.currentThread().getName();
        System.out.println(String.format("%s----,启动",threadName));

        LockSupport.parkNanos(TimeUnit.SECONDS.toNanos(3));

        _lock.lock();

        System.out.println(String.format("%s----,signal前",threadName));

        _cond.signalAll();

        System.out.println(String.format("%s----,signal后",threadName));

        _lock.unlock();




    }
}

---------- END SOURCE ----------