Locks in java are re-entrant , that aids locking to work effectively with Object Oriented Programming . Why ??
Just consider , if you have a base class
class Mybase{
public synchronized doStuff(){
}
}
Now If you have a child class extending the base class then,
public class MyChild extends MyBase{
public synchronized doStuff(){
super.doStuff();
}
}
This would cause a deadlock . Why ??
When on the child doStuff is called a lock on the MyBase object is obtained . Now in MyChild::doStuff when super.doStuff() is called the code would again try to get a new lock on
Mybase and if locks were non re-entrant then the thread would block and hence would cause a deadlock.
