Can this be a case of deadlock ?And how to determine it output ?

[A Agr]

 public class T11 {

	public static void main(String[] args) {
		final StringBuffer s1 = new StringBuffer();
		final StringBuffer s2 = new StringBuffer();
		new Thread() {
			public void run() {
				synchronized (s1) {
					s1.append("A");
					synchronized (s2) {
						s2.append("B");
						System.out.println(s1);
						System.out.println(s2);
					}
				}
			}
		}.start();

		new Thread() {
			public void run() {
				synchronized (s2) {
					s2.append("C");
					synchronized (s1) {
						s1.append("D");
						System.out.println(s1);
						System.out.println(s2);
					}
				}
			}
		}.start();
	}

}
   

[Himalay Majumdar]

Yes it is ...try the following code

public class T11 {   
	  
    public static void main(String[] args) {   
        final StringBuffer s1 = new StringBuffer();   
        final StringBuffer s2 = new StringBuffer();   
        new Thread() {   
            public void run() {   
            	try {
					Thread.sleep(1000);
				} catch (InterruptedException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
                synchronized (s1) {   
                    s1.append("A");   
                    synchronized (s2) {   
                        s2.append("B");   
                        System.out.println(s1);   
                        System.out.println(s2);   
                    }   
                }   
            }   
        }.start();   
  
        new Thread() {   
            public void run() {   
                synchronized (s2) {   
                    s2.append("C");   
                    try {
    					Thread.sleep(3000);
    				} catch (InterruptedException e) {
    					// TODO Auto-generated catch block
    					e.printStackTrace();
    				}
                    synchronized (s1) {   
                        s1.append("D");   
                        System.out.println(s1);   
                        System.out.println(s2);   
                    }   
                }   
            }   
        }.start();   
    }   
  
}  

Getting a deadlock is very unlikely to happen so usually..you will get an output under normal condition. Here by putting sleep method in .I am making it more probable for a deadlock to happen. I many situations..even without a sleep() method..the thread scheduler can behave in such way..that creates deadlock situation.