1<!--$Id: memp_openfd.so,v 10.4 2007/11/08 16:28:12 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_mp_max_openfd</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_mp_max_openfd</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_mp_max_openfd(DB_ENV *env, int maxopenfd); 26<p> 27int 28DB_ENV->get_mp_max_openfd(DB_ENV *env, int *maxopenfdp); 29</pre></b> 30<hr size=1 noshade> 31<b>Description: DB_ENV->set_mp_max_openfd</b> 32<p>The DB_ENV->set_mp_max_openfd method limits the number of file descriptors 33the library will open concurrently when flushing dirty pages from the 34cache.</p> 35<p>The database environment's limit on open file descriptors to flush dirty pages may also be configured using the 36environment's <a href="/ref/env/db_config.html#DB_CONFIG">DB_CONFIG</a> file. The syntax of the entry in that 37file is a single line with the string "set_max_openfd", one or more whitespace 38characters, and the number of open file descriptors. 39Because the <a href="/ref/env/db_config.html#DB_CONFIG">DB_CONFIG</a> file is read when the database environment 40is opened, it will silently overrule configuration done before that 41time.</p> 42<p>The <a href="/api_c/memp_maxwrite.html">DB_ENV->set_mp_max_write</a> method configures a database environment, not only operations 43performed using the specified <a href="/api_c/env_class.html">DB_ENV</a> handle.</p> 44<p>The DB_ENV->set_mp_max_openfd method 45returns a non-zero error value on failure 46and 0 on success. 47</p> 48<b>Parameters</b> <br> 49 <b>maxopenfd</b><ul compact><li>The maximum number of file descriptors that may be concurrently opened 50by the library when flushing dirty pages from the cache.</ul> 51<br> 52<br><b>Errors</b> 53<p>The DB_ENV->set_mp_max_openfd method 54may fail and return one of the following non-zero errors:</p> 55<br> 56<b>EINVAL</b><ul compact><li>An 57invalid flag value or parameter was specified.</ul> 58<br> 59<hr size=1 noshade> 60<b>Description: DB_ENV->get_mp_max_openfd</b> 61<p>The DB_ENV->get_mp_max_openfd method returns the maximum number of file descriptors open.</p> 62<p>The DB_ENV->get_mp_max_openfd method may be called at any time during the life of the 63application.</p> 64<p>The DB_ENV->get_mp_max_openfd method 65returns a non-zero error value on failure 66and 0 on success. 67</p> 68<b>Parameters</b> <br> 69 <b>maxopenfdp</b><ul compact><li>The DB_ENV->get_mp_max_openfd method returns the 70maximum number of file descriptors open in <b>maxopenfdp</b>.</ul> 71<br> 72<hr size=1 noshade> 73<br><b>Class</b> 74<a href="/api_c/env_class.html">DB_ENV</a>, <a href="/api_c/mempfile_class.html">DB_MPOOLFILE</a> 75<br><b>See Also</b> 76<a href="/api_c/memp_list.html">Memory Pools and Related Methods</a> 77</tt> 78<table width="100%"><tr><td><br></td><td align=right> 79<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> 80</td></tr></table> 81<p><font size=1>Copyright (c) 1996,2008 Oracle. All rights reserved.</font> 82</body> 83</html> 84
