1<?xml version="1.0" encoding="UTF-8" standalone="no"?> 2<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> 3<html xmlns="http://www.w3.org/1999/xhtml"> 4 <head> 5 <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /> 6 <title>DbEnv::cdsgroup_begin()</title> 7 <link rel="stylesheet" href="apiReference.css" type="text/css" /> 8 <meta name="generator" content="DocBook XSL Stylesheets V1.73.2" /> 9 <link rel="start" href="index.html" title="Berkeley DB C++ API Reference" /> 10 <link rel="up" href="txn.html" title="Chapter 13. The DbTxn Handle" /> 11 <link rel="prev" href="dbget_transactional.html" title="Db::get_transactional()" /> 12 <link rel="next" href="envget_tx_max.html" title="DbEnv::get_tx_max()" /> 13 </head> 14 <body> 15 <div class="navheader"> 16 <table width="100%" summary="Navigation header"> 17 <tr> 18 <th colspan="3" align="center">DbEnv::cdsgroup_begin()</th> 19 </tr> 20 <tr> 21 <td width="20%" align="left"><a accesskey="p" href="dbget_transactional.html">Prev</a> </td> 22 <th width="60%" align="center">Chapter 13. 23 The DbTxn Handle 24 </th> 25 <td width="20%" align="right"> <a accesskey="n" href="envget_tx_max.html">Next</a></td> 26 </tr> 27 </table> 28 <hr /> 29 </div> 30 <div class="sect1" lang="en" xml:lang="en"> 31 <div class="titlepage"> 32 <div> 33 <div> 34 <h2 class="title" style="clear: both"><a id="envcdsgroup_begin"></a>DbEnv::cdsgroup_begin()</h2> 35 </div> 36 </div> 37 </div> 38 <pre class="programlisting">#include <db_cxx.h> 39 40int 41DbEnv::cdsgroup_begin(DbTxn **tid);</pre> 42 <p> 43 The <code class="methodname">DbEnv::cdsgroup_begin()</code> method allocates a locker ID in an 44 environment configured for Berkeley DB Concurrent Data Store 45 applications. It copies a pointer to a 46 <a class="link" href="txn.html" title="Chapter 13. The DbTxn Handle">DbTxn</a> that uniquely identifies 47 the locker ID into the memory to which <span class="bold"><strong>tid</strong></span> refers. 48 Calling the 49 <a class="xref" href="txncommit.html" title="DbTxn::commit()">DbTxn::commit()</a> method will 50 discard the allocated locker ID. 51 </p> 52 <p> 53 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 54 required. 55 </p> 56 <p> 57 The <code class="methodname">DbEnv::cdsgroup_begin()</code> method may be called at any time during 58 the life of the application. 59 </p> 60 <p> 61 The <code class="methodname">DbEnv::cdsgroup_begin()</code> <span> 62 63 <span> 64 method either returns a non-zero error value or throws an 65 exception that encapsulates a non-zero error value on 66 failure, and returns 0 on success. 67 </span> 68 </span> 69 </p> 70 <div class="sect2" lang="en" xml:lang="en"> 71 <div class="titlepage"> 72 <div> 73 <div> 74 <h3 class="title"><a id="id1712322"></a>Errors</h3> 75 </div> 76 </div> 77 </div> 78 <p> 79 The <code class="methodname">DbEnv::cdsgroup_begin()</code> <span> 80 81 <span> 82 method may fail and throw a <a class="link" href="dbexception.html" title="Chapter 6. The DbException Class">DbException</a> 83 exception, encapsulating one of the following non-zero errors, or return one 84 of the following non-zero errors: 85 </span> 86 </span> 87 </p> 88 <div class="sect3" lang="en" xml:lang="en"> 89 <div class="titlepage"> 90 <div> 91 <div> 92 <h4 class="title"><a id="id1712052"></a>ENOMEM</h4> 93 </div> 94 </div> 95 </div> 96 <p> 97 The maximum number of lockers has been reached. 98 </p> 99 </div> 100 </div> 101 <div class="sect2" lang="en" xml:lang="en"> 102 <div class="titlepage"> 103 <div> 104 <div> 105 <h3 class="title"><a id="id1712323"></a>Class</h3> 106 </div> 107 </div> 108 </div> 109 <p> 110 <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> 111 </p> 112 </div> 113 <div class="sect2" lang="en" xml:lang="en"> 114 <div class="titlepage"> 115 <div> 116 <div> 117 <h3 class="title"><a id="id1712058"></a>See Also</h3> 118 </div> 119 </div> 120 </div> 121 <p> 122 <a class="xref" href="txn.html#txnlist" title="Transaction Subsystem and Related Methods">Transaction Subsystem and Related Methods</a> 123 </p> 124 </div> 125 </div> 126 <div class="navfooter"> 127 <hr /> 128 <table width="100%" summary="Navigation footer"> 129 <tr> 130 <td width="40%" align="left"><a accesskey="p" href="dbget_transactional.html">Prev</a> </td> 131 <td width="20%" align="center"> 132 <a accesskey="u" href="txn.html">Up</a> 133 </td> 134 <td width="40%" align="right"> <a accesskey="n" href="envget_tx_max.html">Next</a></td> 135 </tr> 136 <tr> 137 <td width="40%" align="left" valign="top">Db::get_transactional() </td> 138 <td width="20%" align="center"> 139 <a accesskey="h" href="index.html">Home</a> 140 </td> 141 <td width="40%" align="right" valign="top"> DbEnv::get_tx_max()</td> 142 </tr> 143 </table> 144 </div> 145 </body> 146</html> 147