Intentional deadlock

Locky.java

import java.util.*;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;

public class Locky {

  private static class Boomer implements Runnable {
    private final Lock lockA;
    private final Lock lockB;

    public Boomer(Lock lockA, Lock lockB) {
      this.lockA = lockA;
      this.lockB = lockB;
    }

    @Override
    public void run() {
      try {
        lockA.lock();
        try {
          Thread.sleep(500);
          lockB.lock();
          lockB.unlock();
        } finally {
          lockA.unlock();
        }
      } catch (InterruptedException e) {
        e.printStackTrace(); // Not good for production, good enough for this demo
      }
    }
  }
  
  public static void main(String[] args) {
    Lock l1 = new ReentrantLock();
    Lock l2 = new ReentrantLock();
    Thread t1 = new Thread(new Boomer(l1, l2));
    Thread t2 = new Thread(new Boomer(l2, l1));

    t1.start();
    t2.start();
  }
}