Test program showing lock stack dumps.

package com.mprew.be.service.auto.freecause;

public class Foo {

    final static Object lock = new Object();

    public static void main(String[] args) {
        new Foo().doMain(args);
    }

    private void doMain(String[] args) {
        new Thread(new OurRunnable()).start();
        new Thread(new OurRunnable()).start();
        try {
            Thread.sleep(1000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        Object other = new Object();
        synchronized (lock) {
            synchronized (other) {
                try {
                    other.wait();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        }
    }

    private static class OurRunnable implements Runnable {
        @Override
        public void run() {
            synchronized (lock) {
                try {
                    lock.wait(10000);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        }
    }
}