从另一个同步方法调用同步方法，两者都在不同的 object

Question

Lets say we have two classes A, B and synchronized methods methodA, methodB of the respective classes. If we call synchronized methodB from synchronized methodA whether the thread still hold lock on ObjectA while methodB is still executing?

Class A
{
   public synchronized void methodA()
   {
       //do something;
       synchronized(ObjectB)
       {
          ObjectB.methodB();
       }
   }
}

Class B
{
   public synchronized void methodB()
   {
      //do something
   }
}

Answer 1

The lock will held as long as you are in sync block. It is allowed to lock as many locks as you need but this nested synchronization can impact the overall performance of your application.