Question About Deadlock Situation in Java

Question

I\'m learning about deadlocks in Java, and there\'s this sample code from Sun\'s official tutorial:

Alphonse and Gaston are friends, and great belie

Answer 1

alphonse and gaston are two different objects. Each object has an intrinsic monitor (lock) that is associated with it.

It could happen like this:

alphonse is created. His object monitor is 1.

gaston is created. His object monitor is 2.

alphonse.bow(gaston); alphonse now owns lock #1

gaston.bow(alphonse); gaston now owns lock #2

alphonse calls bowBack on gaston and is waiting for lock #2 gaston calls bowBack on alphonse and is waiting for lock #1

Make sense? Using the synchronized keyword locks that instances monitor for the duration of the method. The example could be rewritten as follows:

public class Deadlock {
    static class Friend {
        private final String name;
        public Friend(String name) {
            this.name = name;
        }
        public String getName() {
            return this.name;
        }
        public void bow(Friend bower) {
            synchronized(this) {            
                        System.out.format("%s: %s has bowed to me!%n", 
                    this.name, bower.getName());
                        bower.bowBack(this);
            }
        }
        public void bowBack(Friend bower) {
            synchronized(this) {
                        System.out.format("%s: %s has bowed back to me!%n",
                    this.name, bower.getName());
            }
        }
    }
}