<!--$Id: memp_openfd.so,v 10.4 2007/11/08 16:28:12 bostic Exp $--> <!--Copyright (c) 1997,2008 Oracle. All rights reserved.--> <!--See the file LICENSE for redistribution information.--> <html> <head> <title>Berkeley DB: DB_ENV->set_mp_max_openfd</title> <meta name="description" content="Berkeley DB: An embedded database programmatic toolkit."> <meta name="keywords" content="embedded,database,programmatic,toolkit,btree,hash,hashing,transaction,transactions,locking,logging,access method,access methods,Java,C,C++"> </head> <body bgcolor=white> <table width="100%"><tr valign=top> <td> <b>DB_ENV->set_mp_max_openfd</b> </td> <td align=right> <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></td> </tr></table> <hr size=1 noshade> <tt> <b><pre> #include <db.h> <p> int DB_ENV->set_mp_max_openfd(DB_ENV *env, int maxopenfd); <p> int DB_ENV->get_mp_max_openfd(DB_ENV *env, int *maxopenfdp); </pre></b> <hr size=1 noshade> <b>Description: DB_ENV->set_mp_max_openfd</b> <p>The DB_ENV->set_mp_max_openfd method limits the number of file descriptors the library will open concurrently when flushing dirty pages from the cache.</p> <p>The database environment's limit on open file descriptors to flush dirty pages may also be configured using the environment's <a href="../ref/env/db_config.html#DB_CONFIG">DB_CONFIG</a> file. The syntax of the entry in that file is a single line with the string "set_max_openfd", one or more whitespace characters, and the number of open file descriptors. Because the <a href="../ref/env/db_config.html#DB_CONFIG">DB_CONFIG</a> file is read when the database environment is opened, it will silently overrule configuration done before that time.</p> <p>The <a href="../api_c/memp_maxwrite.html">DB_ENV->set_mp_max_write</a> method configures a database environment, not only operations performed using the specified <a href="../api_c/env_class.html">DB_ENV</a> handle.</p> <p>The DB_ENV->set_mp_max_openfd method returns a non-zero error value on failure and 0 on success. </p> <b>Parameters</b> <br> <b>maxopenfd</b><ul compact><li>The maximum number of file descriptors that may be concurrently opened by the library when flushing dirty pages from the cache.</ul> <br> <br><b>Errors</b> <p>The DB_ENV->set_mp_max_openfd method may fail and return one of the following non-zero errors:</p> <br> <b>EINVAL</b><ul compact><li>An invalid flag value or parameter was specified.</ul> <br> <hr size=1 noshade> <b>Description: DB_ENV->get_mp_max_openfd</b> <p>The DB_ENV->get_mp_max_openfd method returns the maximum number of file descriptors open.</p> <p>The DB_ENV->get_mp_max_openfd method may be called at any time during the life of the application.</p> <p>The DB_ENV->get_mp_max_openfd method returns a non-zero error value on failure and 0 on success. </p> <b>Parameters</b> <br> <b>maxopenfdp</b><ul compact><li>The DB_ENV->get_mp_max_openfd method returns the maximum number of file descriptors open in <b>maxopenfdp</b>.</ul> <br> <hr size=1 noshade> <br><b>Class</b> <a href="../api_c/env_class.html">DB_ENV</a>, <a href="../api_c/mempfile_class.html">DB_MPOOLFILE</a> <br><b>See Also</b> <a href="../api_c/memp_list.html">Memory Pools and Related Methods</a> </tt> <table width="100%"><tr><td><br></td><td align=right> <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> </td></tr></table> <p><font size=1>Copyright (c) 1996,2008 Oracle. All rights reserved.</font> </body> </html>