<?xml version="1.0" encoding="UTF-8" standalone="no"?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /> <title>DB_ENV->mutex_lock()</title> <link rel="stylesheet" href="apiReference.css" type="text/css" /> <meta name="generator" content="DocBook XSL Stylesheets V1.73.2" /> <link rel="start" href="index.html" title="Berkeley DB C API Reference" /> <link rel="up" href="mutex.html" title="Chapter 9. Mutex Methods" /> <link rel="prev" href="mutexget_tas_spins.html" title="DB_ENV->mutex_get_tas_spins()" /> <link rel="next" href="mutexset_align.html" title="DB_ENV->mutex_set_align()" /> </head> <body> <div class="navheader"> <table width="100%" summary="Navigation header"> <tr> <th colspan="3" align="center">DB_ENV->mutex_lock()</th> </tr> <tr> <td width="20%" align="left"><a accesskey="p" href="mutexget_tas_spins.html">Prev</a> </td> <th width="60%" align="center">Chapter 9. Mutex Methods </th> <td width="20%" align="right"> <a accesskey="n" href="mutexset_align.html">Next</a></td> </tr> </table> <hr /> </div> <div class="sect1" lang="en" xml:lang="en"> <div class="titlepage"> <div> <div> <h2 class="title" style="clear: both"><a id="mutexlock"></a>DB_ENV->mutex_lock()</h2> </div> </div> </div> <pre class="programlisting">#include <db.h> int DB_ENV->mutex_lock(DB_ENV *dbenv, db_mutex_t mutex); </pre> <p> The <code class="methodname">DB_ENV->mutex_lock()</code> method locks the mutex allocated by <a class="xref" href="mutexalloc.html" title="DB_ENV->mutex_alloc()">DB_ENV->mutex_alloc()</a>. The thread of control calling <code class="methodname">DB_ENV->mutex_lock()</code> will block until the lock is available. </p> <p> The <code class="methodname">DB_ENV->mutex_lock()</code> <span> <span> method returns a non-zero error value on failure and 0 on success. </span> </span> </p> <div class="sect2" lang="en" xml:lang="en"> <div class="titlepage"> <div> <div> <h3 class="title"><a id="id1694034"></a>Parameters</h3> </div> </div> </div> <div class="sect3" lang="en" xml:lang="en"> <div class="titlepage"> <div> <div> <h4 class="title"><a id="id1694027"></a>mutex</h4> </div> </div> </div> <p> The <span class="bold"><strong>mutex</strong></span> parameter is a mutex previously allocated by <a class="xref" href="mutexalloc.html" title="DB_ENV->mutex_alloc()">DB_ENV->mutex_alloc()</a>. </p> </div> </div> <div class="sect2" lang="en" xml:lang="en"> <div class="titlepage"> <div> <div> <h3 class="title"><a id="id1694035"></a>Errors</h3> </div> </div> </div> <p> The <code class="methodname">DB_ENV->mutex_lock()</code> <span> <span> method may fail and return one of the following non-zero errors: </span> </span> </p> <div class="sect3" lang="en" xml:lang="en"> <div class="titlepage"> <div> <div> <h4 class="title"><a id="id1694315"></a>EINVAL</h4> </div> </div> </div> <p> An invalid flag value or parameter was specified. </p> </div> </div> <div class="sect2" lang="en" xml:lang="en"> <div class="titlepage"> <div> <div> <h3 class="title"><a id="id1693917"></a>Class</h3> </div> </div> </div> <p> <a class="link" href="env.html" title="Chapter 5. The DB_ENV Handle">DB_ENV</a> </p> </div> <div class="sect2" lang="en" xml:lang="en"> <div class="titlepage"> <div> <div> <h3 class="title"><a id="id1694316"></a>See Also</h3> </div> </div> </div> <p> <a class="xref" href="mutex.html#mutexlist" title="Mutex Methods">Mutex Methods</a> </p> </div> </div> <div class="navfooter"> <hr /> <table width="100%" summary="Navigation footer"> <tr> <td width="40%" align="left"><a accesskey="p" href="mutexget_tas_spins.html">Prev</a> </td> <td width="20%" align="center"> <a accesskey="u" href="mutex.html">Up</a> </td> <td width="40%" align="right"> <a accesskey="n" href="mutexset_align.html">Next</a></td> </tr> <tr> <td width="40%" align="left" valign="top">DB_ENV->mutex_get_tas_spins() </td> <td width="20%" align="center"> <a accesskey="h" href="index.html">Home</a> </td> <td width="40%" align="right" valign="top"> DB_ENV->mutex_set_align()</td> </tr> </table> </div> </body> </html>