mirror of
https://github.com/berkeleydb/libdb.git
synced 2024-11-17 01:26:25 +00:00
181 lines
7.2 KiB
HTML
181 lines
7.2 KiB
HTML
|
<?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_set_align()</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="mutexlock.html" title="DB_ENV->mutex_lock()" />
|
|||
|
|
<link rel="next" href="mutexset_increment.html" title="DB_ENV->mutex_set_increment()" />
|
|||
|
|
</head>
|
|||
|
|
<body>
|
|||
|
|
<div xmlns="" class="navheader">
|
|||
|
|
<div class="libver">
|
|||
|
|
<p>Library Version 11.2.5.2</p>
|
|||
|
|
</div>
|
|||
|
|
<table width="100%" summary="Navigation header">
|
|||
|
|
<tr>
|
|||
|
|
<th colspan="3" align="center">DB_ENV->mutex_set_align()</th>
|
|||
|
|
</tr>
|
|||
|
|
<tr>
|
|||
|
|
<td width="20%" align="left"><a accesskey="p" href="mutexlock.html">Prev</a> </td>
|
|||
|
|
<th width="60%" align="center">Chapter 9.
|
|||
|
|
Mutex Methods
|
|||
|
|
</th>
|
|||
|
|
<td width="20%" align="right"> <a accesskey="n" href="mutexset_increment.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="mutexset_align"></a>DB_ENV->mutex_set_align()</h2>
|
|||
|
|
</div>
|
|||
|
|
</div>
|
|||
|
|
</div>
|
|||
|
|
<pre class="programlisting">#include <db.h>
|
|||
|
|
|
|||
|
|
int
|
|||
|
|
DB_ENV->mutex_set_align(DB_ENV *dbenv, u_int32_t align); </pre>
|
|||
|
|
<p>
|
|||
|
|
Set the mutex alignment, in bytes.
|
|||
|
|
</p>
|
|||
|
|
<p>
|
|||
|
|
It is sometimes advantageous to align mutexes on specific byte
|
|||
|
|
boundaries in order to minimize cache line collisions. The
|
|||
|
|
<code class="methodname">DB_ENV->mutex_set_align()</code> method specifies an alignment for mutexes
|
|||
|
|
allocated by Berkeley DB.
|
|||
|
|
</p>
|
|||
|
|
<p>
|
|||
|
|
The database environment's mutex alignment may also be 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
|
|||
|
|
syntax of the entry in that file is a single line with the string
|
|||
|
|
"mutex_set_align", one or more whitespace characters, and the mutex
|
|||
|
|
alignment in bytes. Because the <a href="../../programmer_reference/env_db_config.html#env_db_config.DB_CONFIG" class="olink">DB_CONFIG</a> file is
|
|||
|
|
read when the database environment is opened, it will silently
|
|||
|
|
overrule configuration done before that time.
|
|||
|
|
</p>
|
|||
|
|
<p>
|
|||
|
|
The <code class="methodname">DB_ENV->mutex_set_align()</code> method configures a database
|
|||
|
|
environment, not only operations performed using the specified
|
|||
|
|
<a class="link" href="env.html" title="Chapter 5. The DB_ENV Handle">DB_ENV</a> handle.
|
|||
|
|
</p>
|
|||
|
|
<p>
|
|||
|
|
The <code class="methodname">DB_ENV->mutex_set_align()</code> method may not be called after the
|
|||
|
|
<a class="xref" href="envopen.html" title="DB_ENV->open()">DB_ENV->open()</a> method is
|
|||
|
|
called. If the database environment already exists when
|
|||
|
|
<a class="xref" href="envopen.html" title="DB_ENV->open()">DB_ENV->open()</a> is called, the
|
|||
|
|
information specified to <code class="methodname">DB_ENV->mutex_set_align()</code> will be ignored.
|
|||
|
|
</p>
|
|||
|
|
<p>
|
|||
|
|
The <code class="methodname">DB_ENV->mutex_set_align()</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="id3922211"></a>Parameters</h3>
|
|||
|
|
</div>
|
|||
|
|
</div>
|
|||
|
|
</div>
|
|||
|
|
<div class="sect3" lang="en" xml:lang="en">
|
|||
|
|
<div class="titlepage">
|
|||
|
|
<div>
|
|||
|
|
<div>
|
|||
|
|
<h4 class="title"><a id="id3921988"></a>align</h4>
|
|||
|
|
</div>
|
|||
|
|
</div>
|
|||
|
|
</div>
|
|||
|
|
<p>
|
|||
|
|
The <span class="bold"><strong>align</strong></span> parameter is the mutex
|
|||
|
|
alignment, in bytes. The mutex alignment must be a power-of-two.
|
|||
|
|
</p>
|
|||
|
|
</div>
|
|||
|
|
</div>
|
|||
|
|
<div class="sect2" lang="en" xml:lang="en">
|
|||
|
|
<div class="titlepage">
|
|||
|
|
<div>
|
|||
|
|
<div>
|
|||
|
|
<h3 class="title"><a id="id3920960"></a>Errors</h3>
|
|||
|
|
</div>
|
|||
|
|
</div>
|
|||
|
|
</div>
|
|||
|
|
<p>
|
|||
|
|
The <code class="methodname">DB_ENV->mutex_set_align()</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="id3922499"></a>EINVAL</h4>
|
|||
|
|
</div>
|
|||
|
|
</div>
|
|||
|
|
</div>
|
|||
|
|
<p>
|
|||
|
|
If the method was called after <a class="xref" href="envopen.html" title="DB_ENV->open()">DB_ENV->open()</a>
|
|||
|
|
was called; or if 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="id3922481"></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="id3921992"></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="mutexlock.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_increment.html">Next</a></td>
|
|||
|
|
</tr>
|
|||
|
|
<tr>
|
|||
|
|
<td width="40%" align="left" valign="top">DB_ENV->mutex_lock() </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_increment()</td>
|
|||
|
|
</tr>
|
|||
|
|
</table>
|
|||
|
|
</div>
|
|||
|
|
</body>
|
|||
|
|
</html>
|