un this code against an existing database.
        Therefore, there is no way that <code class="literal">DB_KEYEXISTS</code>
        will be returned by <code class="methodname">DB-&gt;put()</code>.
    </p>
      <pre class="programlisting">/* 
 * A function that performs a series of writes to a
 * Berkeley DB database. The information written
 * to the database is largely nonsensical, but the
 * mechanism of transactional commit/abort and
 * deadlock detection is illustrated here.
 */
int
writer_thread(vo