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32            <h2 class="title" style="clear: both"><a id="txnnowait"></a>No Wait on Blocks</h2>
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36      <p>
37            Normally when a DB transaction is blocked on a lock request, it
38            must wait until the requested lock becomes available before its
39            thread-of-control can proceed. However, it is possible to configure a
40            transaction handle such that it will report a deadlock rather
41            than wait for the block to clear.
42        </p>
43      <p>
44            You do this on a transaction by transaction basis by specifying
45
46            <span>
47                <code class="literal">DB_TXN_NOWAIT</code>
48                to the
49                <code class="methodname">DB_ENV-&gt;txn_begin()</code>
50                
51                
52                method.
53            </span>
54            
55            
56        </p>
57      <p>
58            For example:
59        </p>
60      <pre class="programlisting">    /* Get the transaction */
61    DB_TXN *txn = NULL;
62    ret = envp-&gt;txn_begin(envp, NULL, &amp;txn, DB_TXN_NOWAIT);
63    if (ret != 0) {
64            envp-&gt;err(envp, ret, "txn_begin failed");
65            return (EXIT_FAILURE);
66    }
67        ....  
68    /* Deadlock detection and exception handling omitted for brevity. */</pre>
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