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>DB_ENV->set_lk_max_locks()</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="lock.html" title="Chapter 6. The DB_LOCK Handle" /> 11 <link rel="prev" href="envset_lk_max_lockers.html" title="DB_ENV->set_lk_max_lockers()" /> 12 <link rel="next" href="envset_lk_max_objects.html" title="DB_ENV->set_lk_max_objects()" /> 13 </head> 14 <body> 15 <div class="navheader"> 16 <table width="100%" summary="Navigation header"> 17 <tr> 18 <th colspan="3" align="center">DB_ENV->set_lk_max_locks()</th> 19 </tr> 20 <tr> 21 <td width="20%" align="left"><a accesskey="p" href="envset_lk_max_lockers.html">Prev</a> </td> 22 <th width="60%" align="center">Chapter 6. 23 The DB_LOCK Handle 24 </th> 25 <td width="20%" align="right"> <a accesskey="n" href="envset_lk_max_objects.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="envset_lk_max_locks"></a>DB_ENV->set_lk_max_locks()</h2> 35 </div> 36 </div> 37 </div> 38 <pre class="programlisting">#include <db.h> 39 40int 41DB_ENV->set_lk_max_locks(DB_ENV *dbenv, u_int32_t max); </pre> 42 <p> 43 Set the maximum number of locks supported by the Berkeley DB 44 environment. This value is used by 45 <a class="xref" href="envopen.html" title="DB_ENV->open()">DB_ENV->open()</a> to estimate how 46 much space to allocate for various lock-table data structures. The 47 default value is 1000 locks. For specific information on configuring 48 the size of the lock subsystem, see <a href="../../programmer_reference/lock_max.html" class="olink">Configuring locking: sizing the system</a>. 49 </p> 50 <p> 51 The database environment's maximum number of locks may also be 52 configured using the environment's <a href="../../programmer_reference/env_db_config.html#env_db_config.DB_CONFIG" class="olink">DB_CONFIG</a> file. The 53 syntax of the entry in that file is a single line with the string 54 "set_lk_max_locks", one or more whitespace characters, and the number 55 of locks. Because the <a href="../../programmer_reference/env_db_config.html#env_db_config.DB_CONFIG" class="olink">DB_CONFIG</a> file is 56 read when the database environment is opened, it will silently 57 overrule configuration done before that time. 58 </p> 59 <p> 60 The <code class="methodname">DB_ENV->set_lk_max_locks()</code> method configures a database 61 environment, not only operations performed using the specified 62 <a class="link" href="env.html" title="Chapter 5. The DB_ENV Handle">DB_ENV</a> handle. 63 </p> 64 <p> 65 The <code class="methodname">DB_ENV->set_lk_max_locks()</code> method may not be called after the 66 <a class="xref" href="envopen.html" title="DB_ENV->open()">DB_ENV->open()</a> method is 67 called. If the database environment already exists when 68 <a class="xref" href="envopen.html" title="DB_ENV->open()">DB_ENV->open()</a> is called, the 69 information specified to <code class="methodname">DB_ENV->set_lk_max_locks()</code> will be ignored. 70 </p> 71 <p> 72 The <code class="methodname">DB_ENV->set_lk_max_locks()</code> <span> 73 <span> 74 method returns a non-zero error value on failure and 0 on success. 75 </span> 76 77 </span> 78 </p> 79 <div class="sect2" lang="en" xml:lang="en"> 80 <div class="titlepage"> 81 <div> 82 <div> 83 <h3 class="title"><a id="id1676140"></a>Parameters</h3> 84 </div> 85 </div> 86 </div> 87 <div class="sect3" lang="en" xml:lang="en"> 88 <div class="titlepage"> 89 <div> 90 <div> 91 <h4 class="title"><a id="id1676151"></a>max</h4> 92 </div> 93 </div> 94 </div> 95 <p> 96 The <span class="bold"><strong>max</strong></span> parameter is the maximum 97 number of locks supported by the Berkeley DB environment. 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="id1676152"></a>Errors</h3> 106 </div> 107 </div> 108 </div> 109 <p> 110 The <code class="methodname">DB_ENV->set_lk_max_locks()</code> <span> 111 <span> 112 method may fail and return one of the following non-zero errors: 113 </span> 114 115 </span> 116 </p> 117 <div class="sect3" lang="en" xml:lang="en"> 118 <div class="titlepage"> 119 <div> 120 <div> 121 <h4 class="title"><a id="id1676134"></a>EINVAL</h4> 122 </div> 123 </div> 124 </div> 125 <p> 126 If the method was called after <a class="xref" href="envopen.html" title="DB_ENV->open()">DB_ENV->open()</a> 127 was called; or if an invalid flag value or parameter was specified. 128 </p> 129 </div> 130 </div> 131 <div class="sect2" lang="en" xml:lang="en"> 132 <div class="titlepage"> 133 <div> 134 <div> 135 <h3 class="title"><a id="id1676210"></a>Class</h3> 136 </div> 137 </div> 138 </div> 139 <p> 140 <a class="link" href="env.html" title="Chapter 5. The DB_ENV Handle">DB_ENV</a>, 141 <a class="link" href="lock.html" title="Chapter 6. The DB_LOCK Handle">DB_LOCK</a> 142 </p> 143 </div> 144 <div class="sect2" lang="en" xml:lang="en"> 145 <div class="titlepage"> 146 <div> 147 <div> 148 <h3 class="title"><a id="id1676203"></a>See Also</h3> 149 </div> 150 </div> 151 </div> 152 <p> 153 <a class="xref" href="lock.html#locklist" title="Locking Subsystem and Related Methods">Locking Subsystem and Related Methods</a> 154 </p> 155 </div> 156 </div> 157 <div class="navfooter"> 158 <hr /> 159 <table width="100%" summary="Navigation footer"> 160 <tr> 161 <td width="40%" align="left"><a accesskey="p" href="envset_lk_max_lockers.html">Prev</a> </td> 162 <td width="20%" align="center"> 163 <a accesskey="u" href="lock.html">Up</a> 164 </td> 165 <td width="40%" align="right"> <a accesskey="n" href="envset_lk_max_objects.html">Next</a></td> 166 </tr> 167 <tr> 168 <td width="40%" align="left" valign="top">DB_ENV->set_lk_max_lockers() </td> 169 <td width="20%" align="center"> 170 <a accesskey="h" href="index.html">Home</a> 171 </td> 172 <td width="40%" align="right" valign="top"> DB_ENV->set_lk_max_objects()</td> 173 </tr> 174 </table> 175 </div> 176 </body> 177</html> 178