sing the database are read-only or
    when the Berkeley DB Concurrent Data Store product is used; the
    Berkeley DB Concurrent Data Store product guarantees deadlock-free
    operation at the expense of reduced concurrency.
</p>
      <p>
    When the deadlock occurs, two (or more) threads of control each request
    additional locks that can never be granted because one of the threads
    of control waiting holds the requested resource.  For example, consider
    two processes: A and B.  Let's say that 