Extended classes synchronized methods locking

Question

Suppose this code

class A
{
    public synchronized void methodA()
    {
        // ...
    }
}

class B extends A
{
    @Override
    public synchronized void methodA()
    {
        // ...
        super.methodA();
    }
}

What lock should be acquired by any thread if it wants to access methodA function of class B and methodA of super class A by super.methodA()?

Answer 1

When you call B b = new B(); b.methodA(); current thread will aquire lock on b , enter B.methodA and call A.methodA. Both methods share the same object and when entering A.methodA the thread will just re-enter the same lock which it already owns.