How this java code produces deadlock?

Question

i am going through oracle docs for deadlock.. i found this code

public class Deadlock {
    static class Friend {
        private final String name;
                 


        

Answer 1

You have 2 objects, alphonse and gaston and 2 threads, Thread1 and Thread2

Suppose this happens:

1. Thread1: alphonse enters the bow() method. and will hold a lock on the alphonse object

2. Thread2: gaston enters the bow() method. and will hold a lock on the gaston object

3. Thread1: alphonse while in the bow() method, calls bowBack() on the gaston object.

   -> Thread1 will block, since Thread2 already has the lock on gaston

4. Thread2: gaston while in the bow() method, calls bowBack() on the alphonse object.

   -> Thread2 will block, since Thread1 already has the lock on alphonse

So now Thread1 is waiting for Thread2. And Thread2 is waiting for Thread1. This is a deadlock.