📄 a00186.html
字号:
<!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: lib/memb.c Source File</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 id="current"><a href="files.html"><span>Files</span></a></li> <li><a href="examples.html"><span>Examples</span></a></li> </ul></div><div class="tabs"> <ul> <li><a href="files.html"><span>File List</span></a></li> <li><a href="globals.html"><span>Globals</span></a></li> </ul></div><h1>lib/memb.c</h1><a href="a00120.html">Go to the documentation of this file.</a><div class="fragment"><pre class="fragment"><a name="l00001"></a>00001 <span class="comment">/*</span><a name="l00002"></a>00002 <span class="comment"> * Copyright (c) 2004, Swedish Institute of Computer Science.</span><a name="l00003"></a>00003 <span class="comment"> * All rights reserved.</span><a name="l00004"></a>00004 <span class="comment"> *</span><a name="l00005"></a>00005 <span class="comment"> * Redistribution and use in source and binary forms, with or without</span><a name="l00006"></a>00006 <span class="comment"> * modification, are permitted provided that the following conditions</span><a name="l00007"></a>00007 <span class="comment"> * are met:</span><a name="l00008"></a>00008 <span class="comment"> * 1. Redistributions of source code must retain the above copyright</span><a name="l00009"></a>00009 <span class="comment"> * notice, this list of conditions and the following disclaimer.</span><a name="l00010"></a>00010 <span class="comment"> * 2. Redistributions in binary form must reproduce the above copyright</span><a name="l00011"></a>00011 <span class="comment"> * notice, this list of conditions and the following disclaimer in the</span><a name="l00012"></a>00012 <span class="comment"> * documentation and/or other materials provided with the distribution.</span><a name="l00013"></a>00013 <span class="comment"> * 3. Neither the name of the Institute nor the names of its contributors</span><a name="l00014"></a>00014 <span class="comment"> * may be used to endorse or promote products derived from this software</span><a name="l00015"></a>00015 <span class="comment"> * without specific prior written permission.</span><a name="l00016"></a>00016 <span class="comment"> *</span><a name="l00017"></a>00017 <span class="comment"> * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND</span><a name="l00018"></a>00018 <span class="comment"> * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE</span><a name="l00019"></a>00019 <span class="comment"> * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE</span><a name="l00020"></a>00020 <span class="comment"> * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE</span><a name="l00021"></a>00021 <span class="comment"> * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL</span><a name="l00022"></a>00022 <span class="comment"> * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS</span><a name="l00023"></a>00023 <span class="comment"> * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)</span><a name="l00024"></a>00024 <span class="comment"> * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT</span><a name="l00025"></a>00025 <span class="comment"> * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY</span><a name="l00026"></a>00026 <span class="comment"> * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF</span><a name="l00027"></a>00027 <span class="comment"> * SUCH DAMAGE.</span><a name="l00028"></a>00028 <span class="comment"> *</span><a name="l00029"></a>00029 <span class="comment"> * This file is part of the uIP TCP/IP stack</span><a name="l00030"></a>00030 <span class="comment"> *</span><a name="l00031"></a>00031 <span class="comment"> * Author: Adam Dunkels <adam@sics.se></span><a name="l00032"></a>00032 <span class="comment"> *</span><a name="l00033"></a>00033 <span class="comment"> * $Id: memb.c,v 1.1 2006/06/12 08:21:43 adam Exp $</span><a name="l00034"></a>00034 <span class="comment"> */</span><a name="l00035"></a>00035 <span class="comment"></span><a name="l00036"></a>00036 <span class="comment">/**</span><a name="l00037"></a>00037 <span class="comment"> * \addtogroup memb</span><a name="l00038"></a>00038 <span class="comment"> * @{</span><a name="l00039"></a>00039 <span class="comment"> */</span><a name="l00040"></a>00040 <span class="comment"></span><a name="l00041"></a>00041 <span class="comment"> /**</span><a name="l00042"></a>00042 <span class="comment"> * \file</span><a name="l00043"></a>00043 <span class="comment"> * Memory block allocation routines.</span><a name="l00044"></a>00044 <span class="comment"> * \author Adam Dunkels <adam@sics.se></span><a name="l00045"></a>00045 <span class="comment"> */</span><a name="l00046"></a>00046 <span class="preprocessor">#include <string.h></span><a name="l00047"></a>00047 <a name="l00048"></a>00048 <span class="preprocessor">#include "<a class="code" href="a00121.html">memb.h</a>"</span><a name="l00049"></a>00049 <a name="l00050"></a>00050 <span class="comment">/*---------------------------------------------------------------------------*/</span><a name="l00051"></a>00051 <span class="keywordtype">void</span><a name="l00052"></a><a class="code" href="a00159.html#gd58a6c7e62ae59bf7a016ded12ca2910">00052</a> <a class="code" href="a00159.html#gd58a6c7e62ae59bf7a016ded12ca2910">memb_init</a>(<span class="keyword">struct</span> <a class="code" href="a00081.html">memb_blocks</a> *m)<a name="l00053"></a>00053 {<a name="l00054"></a>00054 memset(m-><a class="code" href="a00081.html#5595902fd42d874e35a70206fad8f6d0">count</a>, 0, m-><a class="code" href="a00081.html#164124d48fe85bc98d9a300382a5245d">num</a>);<a name="l00055"></a>00055 memset(m-><a class="code" href="a00081.html#b5801722740492e69bcc73687476009f">mem</a>, 0, m-><a class="code" href="a00081.html#b42c7af6114fde5d21206a2e18a7d3ee">size</a> * m-><a class="code" href="a00081.html#164124d48fe85bc98d9a300382a5245d">num</a>);<a name="l00056"></a>00056 }<a name="l00057"></a>00057 <span class="comment">/*---------------------------------------------------------------------------*/</span><a name="l00058"></a>00058 <span class="keywordtype">void</span> *<a name="l00059"></a><a class="code" href="a00159.html#gfe5e93119035e14cc485760a176249ba">00059</a> <a class="code" href="a00159.html#gfe5e93119035e14cc485760a176249ba">memb_alloc</a>(<span class="keyword">struct</span> <a class="code" href="a00081.html">memb_blocks</a> *m)<a name="l00060"></a>00060 {<a name="l00061"></a>00061 <span class="keywordtype">int</span> i;<a name="l00062"></a>00062 <a name="l00063"></a>00063 <span class="keywordflow">for</span>(i = 0; i < m-><a class="code" href="a00081.html#164124d48fe85bc98d9a300382a5245d">num</a>; ++i) {<a name="l00064"></a>00064 <span class="keywordflow">if</span>(m-><a class="code" href="a00081.html#5595902fd42d874e35a70206fad8f6d0">count</a>[i] == 0) {<a name="l00065"></a>00065 <span class="comment">/* If this block was unused, we increase the reference count to</span><a name="l00066"></a>00066 <span class="comment"> indicate that it now is used and return a pointer to the</span><a name="l00067"></a>00067 <span class="comment"> memory block. */</span><a name="l00068"></a>00068 ++(m-><a class="code" href="a00081.html#5595902fd42d874e35a70206fad8f6d0">count</a>[i]);<a name="l00069"></a>00069 return (<span class="keywordtype">void</span> *)((<span class="keywordtype">char</span> *)m-><a class="code" href="a00081.html#b5801722740492e69bcc73687476009f">mem</a> + (i * m-><a class="code" href="a00081.html#b42c7af6114fde5d21206a2e18a7d3ee">size</a>));<a name="l00070"></a>00070 }<a name="l00071"></a>00071 }<a name="l00072"></a>00072 <a name="l00073"></a>00073 <span class="comment">/* No free block was found, so we return NULL to indicate failure to</span><a name="l00074"></a>00074 <span class="comment"> allocate block. */</span><a name="l00075"></a>00075 <span class="keywordflow">return</span> <a class="code" href="a00160.html#g070d2ce7b6bb7e5c05602aa8c308d0c4">NULL</a>;<a name="l00076"></a>00076 }<a name="l00077"></a>00077 <span class="comment">/*---------------------------------------------------------------------------*/</span><a name="l00078"></a>00078 <span class="keywordtype">char</span><a name="l00079"></a><a class="code" href="a00159.html#gceb952d27de8125d5146ac0bee325b8f">00079</a> <a class="code" href="a00159.html#gceb952d27de8125d5146ac0bee325b8f">memb_free</a>(<span class="keyword">struct</span> <a class="code" href="a00081.html">memb_blocks</a> *m, <span class="keywordtype">void</span> *ptr)<a name="l00080"></a>00080 {<a name="l00081"></a>00081 <span class="keywordtype">int</span> i;<a name="l00082"></a>00082 <span class="keywordtype">char</span> *ptr2;<a name="l00083"></a>00083 <a name="l00084"></a>00084 <span class="comment">/* Walk through the list of blocks and try to find the block to</span><a name="l00085"></a>00085 <span class="comment"> which the pointer "ptr" points to. */</span><a name="l00086"></a>00086 ptr2 = (<span class="keywordtype">char</span> *)m-><a class="code" href="a00081.html#b5801722740492e69bcc73687476009f">mem</a>;<a name="l00087"></a>00087 <span class="keywordflow">for</span>(i = 0; i < m->num; ++i) {<a name="l00088"></a>00088 <a name="l00089"></a>00089 <span class="keywordflow">if</span>(ptr2 == (<span class="keywordtype">char</span> *)ptr) {<a name="l00090"></a>00090 <span class="comment">/* We've found to block to which "ptr" points so we decrease the</span><a name="l00091"></a>00091 <span class="comment"> reference count and return the new value of it. */</span><a name="l00092"></a>00092 <span class="keywordflow">if</span>(m-><a class="code" href="a00081.html#5595902fd42d874e35a70206fad8f6d0">count</a>[i] > 0) {<a name="l00093"></a>00093 <span class="comment">/* Make sure that we don't deallocate free memory. */</span><a name="l00094"></a>00094 --(m-><a class="code" href="a00081.html#5595902fd42d874e35a70206fad8f6d0">count</a>[i]);<a name="l00095"></a>00095 }<a name="l00096"></a>00096 <span class="keywordflow">return</span> m-><a class="code" href="a00081.html#5595902fd42d874e35a70206fad8f6d0">count</a>[i];<a name="l00097"></a>00097 }<a name="l00098"></a>00098 ptr2 += m-><a class="code" href="a00081.html#b42c7af6114fde5d21206a2e18a7d3ee">size</a>;<a name="l00099"></a>00099 }<a name="l00100"></a>00100 <span class="keywordflow">return</span> -1;<a name="l00101"></a>00101 }<a name="l00102"></a>00102 <span class="comment">/*---------------------------------------------------------------------------*/</span><a name="l00103"></a>00103 <span class="comment"></span><a name="l00104"></a>00104 <span class="comment">/** @} */</span></pre></div><hr size="1"><address style="align: right;"><small>Generated on Mon Jun 12 10:23:01 2006 for uIP 1.0 by <a href="http://www.doxygen.org/index.html"><img src="doxygen.png" alt="doxygen" align="middle" border="0"></a> 1.4.6 </small></address></body></html>⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -