1<!--$Id: env_set_lk_max_lockers.so,v 1.23 2004/09/28 15:04:20 bostic Exp $--> 2<!--Copyright (c) 1997,2008 Oracle. All rights reserved.--> 3<!--See the file LICENSE for redistribution information.--> 4<html> 5<head> 6<title>Berkeley DB: DB_ENV->set_lk_max_lockers</title> 7<meta name="description" content="Berkeley DB: An embedded database programmatic toolkit."> 8<meta name="keywords" content="embedded,database,programmatic,toolkit,btree,hash,hashing,transaction,transactions,locking,logging,access method,access methods,Java,C,C++"> 9</head> 10<body bgcolor=white> 11<table width="100%"><tr valign=top> 12<td> 13<b>DB_ENV->set_lk_max_lockers</b> 14</td> 15<td align=right> 16<a href="/api_c/api_core.html"><img src="/images/api.gif" alt="API"></a> 17<a href="/ref/toc.html"><img src="/images/ref.gif" alt="Ref"></a></td> 18</tr></table> 19<hr size=1 noshade> 20<tt> 21<b><pre> 22#include <db.h> 23<p> 24int 25DB_ENV->set_lk_max_lockers(DB_ENV *dbenv, u_int32_t max); 26<p> 27int 28DB_ENV->get_lk_max_lockers(DB_ENV *dbenv, u_int32_t *lk_maxp); 29</pre></b> 30<hr size=1 noshade> 31<b>Description: DB_ENV->set_lk_max_lockers</b> 32<p>Set the maximum number of locking entities supported by the Berkeley DB 33environment. This value is used by <a href="/api_c/env_open.html">DB_ENV->open</a> to estimate how 34much space to allocate for various lock-table data structures. The 35default value is 1000 lockers. For specific information on configuring 36the size of the lock subsystem, see <a href="/ref/lock/max.html">Configuring locking: sizing the system</a>.</p> 37<p>The database environment's maximum number of lockers may also be configured using the 38environment's <a href="/ref/env/db_config.html#DB_CONFIG">DB_CONFIG</a> file. The syntax of the entry in that 39file is a single line with the string "set_lk_max_lockers", one or more whitespace 40characters, and the number of lockers. 41Because the <a href="/ref/env/db_config.html#DB_CONFIG">DB_CONFIG</a> file is read when the database environment 42is opened, it will silently overrule configuration done before that 43time.</p> 44<p>The DB_ENV->set_lk_max_lockers method configures a database environment, not only operations 45performed using the specified <a href="/api_c/env_class.html">DB_ENV</a> handle.</p> 46<p>The DB_ENV->set_lk_max_lockers method may not be called after the <a href="/api_c/env_open.html">DB_ENV->open</a> method is 47called. 48If the database environment already exists when 49<a href="/api_c/env_open.html">DB_ENV->open</a> is called, the information specified to DB_ENV->set_lk_max_lockers 50will be ignored. 51</p> 52<p>The DB_ENV->set_lk_max_lockers method 53returns a non-zero error value on failure 54and 0 on success. 55</p> 56<b>Parameters</b> <br> 57 <b>max</b><ul compact><li>The <b>max</b> parameter is the maximum number simultaneous locking 58entities supported by the Berkeley DB environment.</ul> 59<br> 60<br><b>Errors</b> 61<p>The DB_ENV->set_lk_max_lockers method 62may fail and return one of the following non-zero errors:</p> 63<br> 64<b>EINVAL</b><ul compact><li>If the method was called after <a href="/api_c/env_open.html">DB_ENV->open</a> was called; or if an 65invalid flag value or parameter was specified.</ul> 66<br> 67<hr size=1 noshade> 68<b>Description: DB_ENV->get_lk_max_lockers</b> 69<p>The DB_ENV->get_lk_max_lockers method returns the maximum number of lockers.</p> 70<p>The DB_ENV->get_lk_max_lockers method may be called at any time during the life of the 71application.</p> 72<p>The DB_ENV->get_lk_max_lockers method 73returns a non-zero error value on failure 74and 0 on success. 75</p> 76<b>Parameters</b> <br> 77 <b>lk_maxp</b><ul compact><li>The DB_ENV->get_lk_max_lockers method returns the 78maximum number of lockers in <b>lk_maxp</b>.</ul> 79<br> 80<hr size=1 noshade> 81<br><b>Class</b> 82<a href="/api_c/env_class.html">DB_ENV</a>, <a href="/api_c/lock_class.html">DB_LOCK</a> 83<br><b>See Also</b> 84<a href="/api_c/lock_list.html">Locking Subsystem and Related Methods</a> 85</tt> 86<table width="100%"><tr><td><br></td><td align=right> 87<a href="/api_c/api_core.html"><img src="/images/api.gif" alt="API"></a><a href="/ref/toc.html"><img src="/images/ref.gif" alt="Ref"></a> 88</td></tr></table> 89<p><font size=1>Copyright (c) 1996,2008 Oracle. All rights reserved.</font> 90</body> 91</html> 92