How is locking perfomed

[Kalyan Anand]

In this case how the JVM performs lock.

1. When the first synchronzied method is entered, on which objects it holds the lock. Only "this" or "this" as well as "super" ?
2. When the super class method is executed, on which object the lock is held ?

    
public class Widget {
    public synchronized void doSomething() {
        ...
    }
}
 
public class LoggingWidget extends Widget {
    public synchronized void doSomething() {
        ....
        super.doSomething();
        ....
    }
}
 

[Henry Wong]

1. When the first synchronzied method is entered, on which objects it holds the lock. Only "this" or "this" as well as "super" ?

There is no such a thing as a "super" object. The super keyword is used to access the parts of the "this" object that is inherited from the super type. An instance is only one object.

2. When the super class method is executed, on which object the lock is held ?

In the example you provided, it is the "this" object. But as already mentioned, there is no such a thing as a "super" object.

Henry

[Kalyan Anand]

Thanks Henry. I get it.