<?xml version="1.0" encoding="UTF-8" standalone="no"?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /> <title>DbEnv::cdsgroup_begin()</title> <link rel="stylesheet" href="apiReference.css" type="text/css" /> <meta name="generator" content="DocBook XSL Stylesheets V1.73.2" /> <link rel="start" href="index.html" title="Berkeley DB C++ API Reference" /> <link rel="up" href="txn.html" title="Chapter 13. The DbTxn Handle" /> <link rel="prev" href="dbget_transactional.html" title="Db::get_transactional()" /> <link rel="next" href="envget_tx_max.html" title="DbEnv::get_tx_max()" /> </head> <body> <div class="navheader"> <table width="100%" summary="Navigation header"> <tr> <th colspan="3" align="center">DbEnv::cdsgroup_begin()</th> </tr> <tr> <td width="20%" align="left"><a accesskey="p" href="dbget_transactional.html">Prev</a> </td> <th width="60%" align="center">Chapter 13. The DbTxn Handle </th> <td width="20%" align="right"> <a accesskey="n" href="envget_tx_max.html">Next</a></td> </tr> </table> <hr /> </div> <div class="sect1" lang="en" xml:lang="en"> <div class="titlepage"> <div> <div> <h2 class="title" style="clear: both"><a id="envcdsgroup_begin"></a>DbEnv::cdsgroup_begin()</h2> </div> </div> </div> <pre class="programlisting">#include <db_cxx.h> int DbEnv::cdsgroup_begin(DbTxn **tid);</pre> <p> The <code class="methodname">DbEnv::cdsgroup_begin()</code> method allocates a locker ID in an environment configured for Berkeley DB Concurrent Data Store applications. It copies a pointer to a <a class="link" href="txn.html" title="Chapter 13. The DbTxn Handle">DbTxn</a> that uniquely identifies the locker ID into the memory to which <span class="bold"><strong>tid</strong></span> refers. Calling the <a class="xref" href="txncommit.html" title="DbTxn::commit()">DbTxn::commit()</a> method will discard the allocated locker ID. </p> <p> 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 required. </p> <p> The <code class="methodname">DbEnv::cdsgroup_begin()</code> method may be called at any time during the life of the application. </p> <p> The <code class="methodname">DbEnv::cdsgroup_begin()</code> <span> <span> method either returns a non-zero error value or throws an exception that encapsulates a non-zero error value on failure, and returns 0 on success. </span> </span> </p> <div class="sect2" lang="en" xml:lang="en"> <div class="titlepage"> <div> <div> <h3 class="title"><a id="id1712322"></a>Errors</h3> </div> </div> </div> <p> The <code class="methodname">DbEnv::cdsgroup_begin()</code> <span> <span> method may fail and throw a <a class="link" href="dbexception.html" title="Chapter 6. The DbException Class">DbException</a> exception, encapsulating one of the following non-zero errors, or return one of the following non-zero errors: </span> </span> </p> <div class="sect3" lang="en" xml:lang="en"> <div class="titlepage"> <div> <div> <h4 class="title"><a id="id1712052"></a>ENOMEM</h4> </div> </div> </div> <p> The maximum number of lockers has been reached. </p> </div> </div> <div class="sect2" lang="en" xml:lang="en"> <div class="titlepage"> <div> <div> <h3 class="title"><a id="id1712323"></a>Class</h3> </div> </div> </div> <p> <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> </p> </div> <div class="sect2" lang="en" xml:lang="en"> <div class="titlepage"> <div> <div> <h3 class="title"><a id="id1712058"></a>See Also</h3> </div> </div> </div> <p> <a class="xref" href="txn.html#txnlist" title="Transaction Subsystem and Related Methods">Transaction Subsystem and Related Methods</a> </p> </div> </div> <div class="navfooter"> <hr /> <table width="100%" summary="Navigation footer"> <tr> <td width="40%" align="left"><a accesskey="p" href="dbget_transactional.html">Prev</a> </td> <td width="20%" align="center"> <a accesskey="u" href="txn.html">Up</a> </td> <td width="40%" align="right"> <a accesskey="n" href="envget_tx_max.html">Next</a></td> </tr> <tr> <td width="40%" align="left" valign="top">Db::get_transactional() </td> <td width="20%" align="center"> <a accesskey="h" href="index.html">Home</a> </td> <td width="40%" align="right" valign="top"> DbEnv::get_tx_max()</td> </tr> </table> </div> </body> </html>