1<?xml version="1.0" encoding="UTF-8" standalone="no"?> 2<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> 3<html xmlns="http://www.w3.org/1999/xhtml"> 4 <head> 5 <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /> 6 <title>DB_ENV->memp_trickle()</title> 7 <link rel="stylesheet" href="apiReference.css" type="text/css" /> 8 <meta name="generator" content="DocBook XSL Stylesheets V1.73.2" /> 9 <link rel="start" href="index.html" title="Berkeley DB C API Reference" /> 10 <link rel="up" href="memp.html" title="Chapter��8.�� The DB_MPOOLFILE Handle" /> 11 <link rel="prev" href="mempsync.html" title="DB_ENV->memp_sync()" /> 12 <link rel="next" href="envset_cache_max.html" title="DB_ENV->set_cache_max()" /> 13 </head> 14 <body> 15 <div class="navheader"> 16 <table width="100%" summary="Navigation header"> 17 <tr> 18 <th colspan="3" align="center">DB_ENV->memp_trickle()</th> 19 </tr> 20 <tr> 21 <td width="20%" align="left"><a accesskey="p" href="mempsync.html">Prev</a>��</td> 22 <th width="60%" align="center">Chapter��8.�� 23 The DB_MPOOLFILE Handle 24 </th> 25 <td width="20%" align="right">��<a accesskey="n" href="envset_cache_max.html">Next</a></td> 26 </tr> 27 </table> 28 <hr /> 29 </div> 30 <div class="sect1" lang="en" xml:lang="en"> 31 <div class="titlepage"> 32 <div> 33 <div> 34 <h2 class="title" style="clear: both"><a id="memptrickle"></a>DB_ENV->memp_trickle()</h2> 35 </div> 36 </div> 37 </div> 38 <pre class="programlisting">#include <db.h> 39 40int 41DB_ENV->memp_trickle(DB_ENV *env, int percent, int *nwrotep); </pre> 42 <p> 43 The <code class="methodname">DB_ENV->memp_trickle()</code> method ensures that a specified percent of 44 the pages in the cache are clean, by writing dirty pages 45 to their backing files. 46 </p> 47 <p> 48 The purpose of the <code class="methodname">DB_ENV->memp_trickle()</code> function is to enable a 49 memory pool manager to ensure that a page is always available for 50 reading in new information without having to wait for a write. 51 </p> 52 <p> 53 The <code class="methodname">DB_ENV->memp_trickle()</code> <span> 54 <span> 55 method returns a non-zero error value on failure and 0 on success. 56 </span> 57 58 </span> 59 </p> 60 <div class="sect2" lang="en" xml:lang="en"> 61 <div class="titlepage"> 62 <div> 63 <div> 64 <h3 class="title"><a id="id1687847"></a>Parameters</h3> 65 </div> 66 </div> 67 </div> 68 <div class="sect3" lang="en" xml:lang="en"> 69 <div class="titlepage"> 70 <div> 71 <div> 72 <h4 class="title"><a id="id1688063"></a>nwrotep</h4> 73 </div> 74 </div> 75 </div> 76 <p> 77 The <span class="bold"><strong>nwrotep</strong></span> parameter references 78 memory into which the number of pages written to reach the specified 79 percentage is copied. 80 </p> 81 </div> 82 <div class="sect3" lang="en" xml:lang="en"> 83 <div class="titlepage"> 84 <div> 85 <div> 86 <h4 class="title"><a id="id1688202"></a>percent</h4> 87 </div> 88 </div> 89 </div> 90 <p> 91 The <span class="bold"><strong>percent</strong></span> parameter is the percent 92 of the pages in the cache that should be clean. 93 </p> 94 </div> 95 </div> 96 <div class="sect2" lang="en" xml:lang="en"> 97 <div class="titlepage"> 98 <div> 99 <div> 100 <h3 class="title"><a id="id1688064"></a>Errors</h3> 101 </div> 102 </div> 103 </div> 104 <p> 105 The <code class="methodname">DB_ENV->memp_trickle()</code> <span> 106 <span> 107 method may fail and return one of the following non-zero errors: 108 </span> 109 110 </span> 111 following non-zero errors: 112 </p> 113 <div class="sect3" lang="en" xml:lang="en"> 114 <div class="titlepage"> 115 <div> 116 <div> 117 <h4 class="title"><a id="id1688030"></a>EINVAL</h4> 118 </div> 119 </div> 120 </div> 121 <p> 122 An invalid flag value or parameter was specified. 123 </p> 124 </div> 125 </div> 126 <div class="sect2" lang="en" xml:lang="en"> 127 <div class="titlepage"> 128 <div> 129 <div> 130 <h3 class="title"><a id="id1688151"></a>Class</h3> 131 </div> 132 </div> 133 </div> 134 <p> 135 <a class="link" href="env.html" title="Chapter��5.�� The DB_ENV Handle">DB_ENV</a>, <a class="link" href="memp.html" title="Chapter��8.�� The DB_MPOOLFILE Handle">DB_MPOOLFILE</a> 136 </p> 137 </div> 138 <div class="sect2" lang="en" xml:lang="en"> 139 <div class="titlepage"> 140 <div> 141 <div> 142 <h3 class="title"><a id="id1687965"></a>See Also</h3> 143 </div> 144 </div> 145 </div> 146 <p> 147 <a class="xref" href="memp.html#memplist" title="Memory Pools and Related Methods">Memory Pools and Related Methods</a> 148 </p> 149 </div> 150 </div> 151 <div class="navfooter"> 152 <hr /> 153 <table width="100%" summary="Navigation footer"> 154 <tr> 155 <td width="40%" align="left"><a accesskey="p" href="mempsync.html">Prev</a>��</td> 156 <td width="20%" align="center"> 157 <a accesskey="u" href="memp.html">Up</a> 158 </td> 159 <td width="40%" align="right">��<a accesskey="n" href="envset_cache_max.html">Next</a></td> 160 </tr> 161 <tr> 162 <td width="40%" align="left" valign="top">DB_ENV->memp_sync()��</td> 163 <td width="20%" align="center"> 164 <a accesskey="h" href="index.html">Home</a> 165 </td> 166 <td width="40%" align="right" valign="top">��DB_ENV->set_cache_max()</td> 167 </tr> 168 </table> 169 </div> 170 </body> 171</html> 172