docs/api_reference/CXX/envcdsgroup_begin.html

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  21           <th colspan="3" align="center">DbEnv::cdsgroup_begin()</th>
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  24           <td width="20%" align="left"><a accesskey="p" href="dbget_transactional.html">Prev</a> </td>
  25           <th width="60%" align="center">Chapter 13.
  26                 The DbTxn Handle
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  37             <h2 class="title" style="clear: both"><a id="envcdsgroup_begin"></a>DbEnv::cdsgroup_begin()</h2>
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  41       <pre class="programlisting">#include &lt;db_cxx.h&gt;
  42
  43 int
  44 DbEnv::cdsgroup_begin(DbTxn **tid);</pre>
  45       <p>
  46          The <code class="methodname">DbEnv::cdsgroup_begin()</code> method allocates a locker ID in an
  47          environment configured for Berkeley DB Concurrent Data Store
  48          applications.  It copies a pointer to a
  49          <a class="link" href="txn.html" title="Chapter 13.  The DbTxn Handle">DbTxn</a>  that uniquely identifies
  50          the locker ID into the memory to which <span class="bold"><strong>tid</strong></span> refers.
  51          Calling the
  52          <a class="xref" href="txncommit.html" title="DbTxn::commit()">DbTxn::commit()</a>  method will
  53          discard the allocated locker ID.
  54     </p>
  55       <p>
  56          See <a href="../../programmer_reference/cam.html#cam_intro" class="olink">Berkeley DB Concurrent Data Store applications</a> for more information about when this is
  57          required.
  58     </p>
  59       <p>
  60          The <code class="methodname">DbEnv::cdsgroup_begin()</code> method may be called at any time during
  61          the life of the application.
  62     </p>
  63       <p>
  64          The <code class="methodname">DbEnv::cdsgroup_begin()</code> <span>
  65
  66             <span>
  67                 method either returns a non-zero error value or throws an
  68                 exception that encapsulates a non-zero error value on
  69                 failure, and returns 0 on success.
  70             </span>
  71         </span>
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  77               <h3 class="title"><a id="idp4874904"></a>Errors</h3>
  78             </div>
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  80         </div>
  81         <p>
  82                      The <code class="methodname">DbEnv::cdsgroup_begin()</code> <span>
  83
  84             <span>
  85                 method may fail and throw a <a class="link" href="dbexception.html" title="Chapter 6. The DbException Class">DbException</a>
  86                 exception, encapsulating one of the following non-zero errors, or return one
  87                 of the following non-zero errors:
  88             </span>
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  93             <div>
  94               <div>
  95                 <h4 class="title"><a id="idp4885184"></a>ENOMEM</h4>
  96               </div>
  97             </div>
  98           </div>
  99           <p>
 100                 The maximum number of lockers has been reached.
 101             </p>
 102         </div>
 103       </div>
 104       <div class="sect2" lang="en" xml:lang="en">
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 107             <div>
 108               <h3 class="title"><a id="idp4879832"></a>Class</h3>
 109             </div>
 110           </div>
 111         </div>
 112         <p>
 113                 <a class="link" href="env.html" title="Chapter 5.  The DbEnv Handle">DbEnv</a>, <a class="link" href="txn.html" title="Chapter 13.  The DbTxn Handle">DbTxn</a>
 114             </p>
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 120               <h3 class="title"><a id="idp4886480"></a>See Also</h3>
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 124         <p>
 125                      <a class="xref" href="txn.html#txnlist" title="Transaction Subsystem and Related Methods">Transaction Subsystem and Related Methods</a>
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