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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html><head><meta http-equiv="Content-Type" content="text/html;charset=iso-8859-1"><title>uIP 1.0: Memory block management functions</title><link href="doxygen.css" rel="stylesheet" type="text/css"><link href="tabs.css" rel="stylesheet" type="text/css"></head><body><!-- Generated by Doxygen 1.4.6 --><div class="tabs"> <ul> <li><a href="main.html"><span>Main Page</span></a></li> <li><a href="modules.html"><span>Modules</span></a></li> <li><a href="classes.html"><span>Data Structures</span></a></li> <li><a href="files.html"><span>Files</span></a></li> <li><a href="examples.html"><span>Examples</span></a></li> </ul></div><h1>Memory block management functions</h1><hr><a name="_details"></a><h2>Detailed Description</h2>The memory block allocation routines provide a simple yet powerful set of functions for managing a set of memory blocks of fixed size. <p>A set of memory blocks is statically declared with the <a class="el" href="a00159.html#gf31774d02a69fd3f1c2b282454438cba">MEMB()</a> macro. Memory blocks are allocated from the declared memory by the <a class="el" href="a00159.html#gfe5e93119035e14cc485760a176249ba">memb_alloc()</a> function, and are deallocated with the <a class="el" href="a00159.html#gceb952d27de8125d5146ac0bee325b8f">memb_free()</a> function.<p><dl compact><dt><b>Note:</b></dt><dd>Because of namespace clashes only one <a class="el" href="a00159.html#gf31774d02a69fd3f1c2b282454438cba">MEMB()</a> can be declared per C module, and the name scope of a <a class="el" href="a00159.html#gf31774d02a69fd3f1c2b282454438cba">MEMB()</a> memory block is local to each C module.</dd></dl>The following example shows how to declare and use a memory block called "cmem" which has 8 chunks of memory with each memory chunk being 20 bytes large. <p><table border="0" cellpadding="0" cellspacing="0"><tr><td></td></tr><tr><td colspan="2"><br><h2>Files</h2></td></tr><tr><td class="memItemLeft" nowrap align="right" valign="top">file </td><td class="memItemRight" valign="bottom"><a class="el" href="a00120.html">memb.c</a></td></tr><tr><td class="mdescLeft"> </td><td class="mdescRight">Memory block allocation routines. <br></td></tr><p><tr><td class="memItemLeft" nowrap align="right" valign="top">file </td><td class="memItemRight" valign="bottom"><a class="el" href="a00121.html">memb.h</a></td></tr><tr><td class="mdescLeft"> </td><td class="mdescRight">Memory block allocation routines. <br></td></tr><p><tr><td colspan="2"><br><h2>Data Structures</h2></td></tr><tr><td class="memItemLeft" nowrap align="right" valign="top">struct </td><td class="memItemRight" valign="bottom"><a class="el" href="a00081.html">memb_blocks</a></td></tr><tr><td colspan="2"><br><h2>Defines</h2></td></tr><tr><td class="memItemLeft" nowrap align="right" valign="top"><a class="anchor" name="ga680bc3f3a1a8a6aec20fe729d138cb8"></a><!-- doxytag: member="memb::MEMB_CONCAT2" ref="ga680bc3f3a1a8a6aec20fe729d138cb8" args="(s1, s2)" -->#define </td><td class="memItemRight" valign="bottom"><a class="el" href="a00159.html#ga680bc3f3a1a8a6aec20fe729d138cb8">MEMB_CONCAT2</a>(s1, s2) s1##s2</td></tr><tr><td class="memItemLeft" nowrap align="right" valign="top"><a class="anchor" name="g720ac440c7b24bdd07c53ba146e36fb2"></a><!-- doxytag: member="memb::MEMB_CONCAT" ref="g720ac440c7b24bdd07c53ba146e36fb2" args="(s1, s2)" -->#define </td><td class="memItemRight" valign="bottom"><a class="el" href="a00159.html#g720ac440c7b24bdd07c53ba146e36fb2">MEMB_CONCAT</a>(s1, s2) MEMB_CONCAT2(s1, s2)</td></tr><tr><td class="memItemLeft" nowrap align="right" valign="top">#define </td><td class="memItemRight" valign="bottom"><a class="el" href="a00159.html#gf31774d02a69fd3f1c2b282454438cba">MEMB</a>(name, structure, num)</td></tr><tr><td class="mdescLeft"> </td><td class="mdescRight">Declare a memory block. <a href="#gf31774d02a69fd3f1c2b282454438cba"></a><br></td></tr><tr><td colspan="2"><br><h2>Functions</h2></td></tr><tr><td class="memItemLeft" nowrap align="right" valign="top">void </td><td class="memItemRight" valign="bottom"><a class="el" href="a00159.html#gd58a6c7e62ae59bf7a016ded12ca2910">memb_init</a> (struct <a class="el" href="a00081.html">memb_blocks</a> *m)</td></tr><tr><td class="mdescLeft"> </td><td class="mdescRight">Initialize a memory block that was declared with <a class="el" href="a00159.html#gf31774d02a69fd3f1c2b282454438cba">MEMB()</a>. <a href="#gd58a6c7e62ae59bf7a016ded12ca2910"></a><br></td></tr><tr><td class="memItemLeft" nowrap align="right" valign="top">void * </td><td class="memItemRight" valign="bottom"><a class="el" href="a00159.html#gfe5e93119035e14cc485760a176249ba">memb_alloc</a> (struct <a class="el" href="a00081.html">memb_blocks</a> *m)</td></tr><tr><td class="mdescLeft"> </td><td class="mdescRight">Allocate a memory block from a block of memory declared with <a class="el" href="a00159.html#gf31774d02a69fd3f1c2b282454438cba">MEMB()</a>. <a href="#gfe5e93119035e14cc485760a176249ba"></a><br></td></tr><tr><td class="memItemLeft" nowrap align="right" valign="top">char </td><td class="memItemRight" valign="bottom"><a class="el" href="a00159.html#gceb952d27de8125d5146ac0bee325b8f">memb_free</a> (struct <a class="el" href="a00081.html">memb_blocks</a> *m, void *ptr)</td></tr><tr><td class="mdescLeft"> </td><td class="mdescRight">Deallocate a memory block from a memory block previously declared with <a class="el" href="a00159.html#gf31774d02a69fd3f1c2b282454438cba">MEMB()</a>. <a href="#gceb952d27de8125d5146ac0bee325b8f"></a><br></td></tr></table><hr><h2>Define Documentation</h2><a class="anchor" name="gf31774d02a69fd3f1c2b282454438cba"></a><!-- doxytag: member="memb.h::MEMB" ref="gf31774d02a69fd3f1c2b282454438cba" args="(name, structure, num)" --><p><table class="mdTable" cellpadding="2" cellspacing="0"> <tr> <td class="mdRow"> <table cellpadding="0" cellspacing="0" border="0"> <tr> <td class="md" nowrap valign="top">#define MEMB </td> <td class="md" valign="top">( </td> <td class="md" nowrap valign="top">name, <tr> <td class="md" nowrap align="right"></td> <td class="md"></td> <td class="md" nowrap>structure, <tr> <td class="md" nowrap align="right"></td> <td class="md"></td> <td class="md" nowrap>num </td> <td class="mdname1" valign="top" nowrap> </td> <td class="md" valign="top"> ) </td> <td class="md" nowrap></td> </tr> </table> </td> </tr></table><table cellspacing="5" cellpadding="0" border="0"> <tr> <td> </td> <td><p><b>Value:</b><div class="fragment"><pre class="fragment"><span class="keyword">static</span> <span class="keywordtype">char</span> <a class="code" href="a00159.html#g720ac440c7b24bdd07c53ba146e36fb2">MEMB_CONCAT</a>(name,_memb_count)[num]; \ <span class="keyword">static</span> structure <a class="code" href="a00159.html#g720ac440c7b24bdd07c53ba146e36fb2">MEMB_CONCAT</a>(name,_memb_mem)[num]; \ <span class="keyword">static</span> <span class="keyword">struct </span><a class="code" href="a00081.html">memb_blocks</a> name = {<span class="keyword">sizeof</span>(structure), <a class="code" href="a00081.html#164124d48fe85bc98d9a300382a5245d">num</a>, \ <a class="code" href="a00159.html#g720ac440c7b24bdd07c53ba146e36fb2">MEMB_CONCAT</a>(name,_memb_count), \ (<span class="keywordtype">void</span> *)<a class="code" href="a00159.html#g720ac440c7b24bdd07c53ba146e36fb2">MEMB_CONCAT</a>(name,_memb_mem)}</pre></div>Declare a memory block. <p>This macro is used to staticall declare a block of memory that can be used by the block allocation functions. The macro statically declares a C array with a size that matches the specified number of blocks and their individual sizes.<p>Example: <div class="fragment"><pre class="fragment"><a class="code" href="a00159.html#gf31774d02a69fd3f1c2b282454438cba">MEMB</a>(connections, <span class="keyword">sizeof</span>(<span class="keyword">struct</span> connection), 16);</pre></div><p><dl compact><dt><b>Parameters:</b></dt><dd> <table border="0" cellspacing="2" cellpadding="0"> <tr><td valign="top"></td><td valign="top"><em>name</em> </td><td>The name of the memory block (later used with <a class="el" href="a00159.html#gd58a6c7e62ae59bf7a016ded12ca2910">memb_init()</a>, <a class="el" href="a00159.html#gfe5e93119035e14cc485760a176249ba">memb_alloc()</a> and <a class="el" href="a00159.html#gceb952d27de8125d5146ac0bee325b8f">memb_free()</a>).</td></tr> <tr><td valign="top"></td><td valign="top"><em>size</em> </td><td>The size of each memory chunk, in bytes.</td></tr> <tr><td valign="top"></td><td valign="top"><em>num</em> </td><td>The total number of memory chunks in the block. </td></tr> </table></dl><dl compact><dt><b>Examples: </b></dt><dd><a class="el" href="a00044.html#a206">telnetd.c</a>.</dl><p>Definition at line <a class="el" href="a00187.html#l00098">98</a> of file <a class="el" href="a00187.html">memb.h</a>. </td> </tr></table><hr><h2>Function Documentation</h2><a class="anchor" name="gfe5e93119035e14cc485760a176249ba"></a><!-- doxytag: member="memb.c::memb_alloc" ref="gfe5e93119035e14cc485760a176249ba" args="(struct memb_blocks *m)" --><p><table class="mdTable" cellpadding="2" cellspacing="0"> <tr> <td class="mdRow"> <table cellpadding="0" cellspacing="0" border="0"> <tr> <td class="md" nowrap valign="top">void * memb_alloc </td> <td class="md" valign="top">( </td> <td class="md" nowrap valign="top">struct <a class="el" href="a00081.html">memb_blocks</a> * </td> <td class="mdname1" valign="top" nowrap> <em>m</em> </td> <td class="md" valign="top"> ) </td>⌨️ 快捷键说明
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