SE450: Scenario with Locks [26/36]

1. First thread calls add and acquires lock, then executes
   elements[tail] = anObject;
2. Second thread calls add and tries to acquire lock, but it is blocked
   
3. First thread executes
   tail++;
4. First thread completes add, releases lock
   
5. Second thread unblocked
6. Second thread acquires lock, starts executing protected code