<!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>Apache Portable Runtime: apr_atomic.h Source File</title> <link href="doxygen.css" rel="stylesheet" type="text/css"> </head><body> <!-- Generated by Doxygen 1.3.9.1 --> <div class="qindex"><a class="qindex" href="index.html">Main Page</a> | <a class="qindex" href="modules.html">Modules</a> | <a class="qindex" href="annotated.html">Data Structures</a> | <a class="qindex" href="files.html">File List</a> | <a class="qindex" href="functions.html">Data Fields</a> | <a class="qindex" href="globals.html">Globals</a> | <a class="qindex" href="pages.html">Related Pages</a></div> <div class="nav"> <a class="el" href="dir_000000.html">home</a> / <a class="el" href="dir_000001.html">oden</a> / <a class="el" href="dir_000002.html">RPM</a> / <a class="el" href="dir_000003.html">BUILD</a> / <a class="el" href="dir_000004.html">apr-1.1.1</a> / <a class="el" href="dir_000005.html">include</a></div> <h1>apr_atomic.h</h1><a href="apr__atomic_8h.html">Go to the documentation of this file.</a><div class="fragment"><pre class="fragment">00001 <span class="comment">/* Copyright 2000-2004 The Apache Software Foundation</span> 00002 <span class="comment"> *</span> 00003 <span class="comment"> * Licensed under the Apache License, Version 2.0 (the "License");</span> 00004 <span class="comment"> * you may not use this file except in compliance with the License.</span> 00005 <span class="comment"> * You may obtain a copy of the License at</span> 00006 <span class="comment"> *</span> 00007 <span class="comment"> * http://www.apache.org/licenses/LICENSE-2.0</span> 00008 <span class="comment"> *</span> 00009 <span class="comment"> * Unless required by applicable law or agreed to in writing, software</span> 00010 <span class="comment"> * distributed under the License is distributed on an "AS IS" BASIS,</span> 00011 <span class="comment"> * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.</span> 00012 <span class="comment"> * See the License for the specific language governing permissions and</span> 00013 <span class="comment"> * limitations under the License.</span> 00014 <span class="comment"> */</span> 00015 00016 <span class="preprocessor">#ifndef APR_ATOMIC_H</span> 00017 <span class="preprocessor"></span><span class="preprocessor">#define APR_ATOMIC_H</span> 00018 <span class="preprocessor"></span><span class="comment"></span> 00019 <span class="comment">/**</span> 00020 <span class="comment"> * @file apr_atomic.h</span> 00021 <span class="comment"> * @brief APR Atomic Operations</span> 00022 <span class="comment"> */</span> 00023 00024 <span class="preprocessor">#include "<a class="code" href="apr_8h.html">apr.h</a>"</span> 00025 <span class="preprocessor">#include "<a class="code" href="apr__pools_8h.html">apr_pools.h</a>"</span> 00026 00027 <span class="preprocessor">#ifdef __cplusplus</span> 00028 <span class="preprocessor"></span><span class="keyword">extern</span> <span class="stringliteral">"C"</span> { 00029 <span class="preprocessor">#endif</span> 00030 <span class="preprocessor"></span><span class="comment"></span> 00031 <span class="comment">/**</span> 00032 <span class="comment"> * @defgroup apr_atomic Atomic Operations</span> 00033 <span class="comment"> * @ingroup APR </span> 00034 <span class="comment"> * @{</span> 00035 <span class="comment"> */</span> 00036 <span class="comment"></span> 00037 <span class="comment">/**</span> 00038 <span class="comment"> * this function is required on some platforms to initialize the</span> 00039 <span class="comment"> * atomic operation's internal structures</span> 00040 <span class="comment"> * @param p pool</span> 00041 <span class="comment"> * @return APR_SUCCESS on successful completion</span> 00042 <span class="comment"> */</span> 00043 <a class="code" href="group__apr__platform.html#ga123">APR_DECLARE</a>(apr_status_t) apr_atomic_init(apr_pool_t *p); 00044 00045 <span class="comment">/*</span> 00046 <span class="comment"> * Atomic operations on 32-bit values</span> 00047 <span class="comment"> * Note: Each of these functions internally implements a memory barrier</span> 00048 <span class="comment"> * on platforms that require it</span> 00049 <span class="comment"> */</span> 00050 <span class="comment"></span> 00051 <span class="comment">/**</span> 00052 <span class="comment"> * atomically read an apr_uint32_t from memory</span> 00053 <span class="comment"> * @param mem the pointer</span> 00054 <span class="comment"> */</span> 00055 APR_DECLARE(apr_uint32_t) apr_atomic_read32(volatile apr_uint32_t *mem); 00056 <span class="comment"></span> 00057 <span class="comment">/**</span> 00058 <span class="comment"> * atomically set an apr_uint32_t in memory</span> 00059 <span class="comment"> * @param mem pointer to the object</span> 00060 <span class="comment"> * @param val value that the object will assume</span> 00061 <span class="comment"> */</span> 00062 APR_DECLARE(<span class="keywordtype">void</span>) apr_atomic_set32(volatile apr_uint32_t *mem, apr_uint32_t val); 00063 <span class="comment"></span> 00064 <span class="comment">/**</span> 00065 <span class="comment"> * atomically add 'val' to an apr_uint32_t</span> 00066 <span class="comment"> * @param mem pointer to the object</span> 00067 <span class="comment"> * @param val amount to add</span> 00068 <span class="comment"> * @return old value pointed to by mem</span> 00069 <span class="comment"> */</span> 00070 APR_DECLARE(apr_uint32_t) apr_atomic_add32(volatile apr_uint32_t *mem, apr_uint32_t val); 00071 <span class="comment"></span> 00072 <span class="comment">/**</span> 00073 <span class="comment"> * atomically subtract 'val' from an apr_uint32_t</span> 00074 <span class="comment"> * @param mem pointer to the object</span> 00075 <span class="comment"> * @param val amount to subtract</span> 00076 <span class="comment"> */</span> 00077 APR_DECLARE(<span class="keywordtype">void</span>) apr_atomic_sub32(volatile apr_uint32_t *mem, apr_uint32_t val); 00078 <span class="comment"></span> 00079 <span class="comment">/**</span> 00080 <span class="comment"> * atomically increment an apr_uint32_t by 1</span> 00081 <span class="comment"> * @param mem pointer to the object</span> 00082 <span class="comment"> * @return old value pointed to by mem</span> 00083 <span class="comment"> */</span> 00084 APR_DECLARE(apr_uint32_t) apr_atomic_inc32(volatile apr_uint32_t *mem); 00085 <span class="comment"></span> 00086 <span class="comment">/**</span> 00087 <span class="comment"> * atomically decrement an apr_uint32_t by 1</span> 00088 <span class="comment"> * @param mem pointer to the atomic value</span> 00089 <span class="comment"> * @return zero if the value becomes zero on decrement, otherwise non-zero</span> 00090 <span class="comment"> */</span> 00091 APR_DECLARE(<span class="keywordtype">int</span>) apr_atomic_dec32(volatile apr_uint32_t *mem); 00092 <span class="comment"></span> 00093 <span class="comment">/**</span> 00094 <span class="comment"> * compare an apr_uint32_t's value with 'cmp'.</span> 00095 <span class="comment"> * If they are the same swap the value with 'with'</span> 00096 <span class="comment"> * @param mem pointer to the value</span> 00097 <span class="comment"> * @param with what to swap it with</span> 00098 <span class="comment"> * @param cmp the value to compare it to</span> 00099 <span class="comment"> * @return the old value of *mem</span> 00100 <span class="comment"> */</span> 00101 APR_DECLARE(apr_uint32_t) apr_atomic_cas32(volatile apr_uint32_t *mem, apr_uint32_t with, 00102 apr_uint32_t cmp); 00103 <span class="comment"></span> 00104 <span class="comment">/**</span> 00105 <span class="comment"> * exchange an apr_uint32_t's value with 'val'.</span> 00106 <span class="comment"> * @param mem pointer to the value</span> 00107 <span class="comment"> * @param val what to swap it with</span> 00108 <span class="comment"> * @return the old value of *mem</span> 00109 <span class="comment"> */</span> 00110 APR_DECLARE(apr_uint32_t) apr_atomic_xchg32(volatile apr_uint32_t *mem, apr_uint32_t val); 00111 <span class="comment"></span> 00112 <span class="comment">/**</span> 00113 <span class="comment"> * compare the pointer's value with cmp.</span> 00114 <span class="comment"> * If they are the same swap the value with 'with'</span> 00115 <span class="comment"> * @param mem pointer to the pointer</span> 00116 <span class="comment"> * @param with what to swap it with</span> 00117 <span class="comment"> * @param cmp the value to compare it to</span> 00118 <span class="comment"> * @return the old value of the pointer</span> 00119 <span class="comment"> */</span> 00120 APR_DECLARE(<span class="keywordtype">void</span>*) apr_atomic_casptr(volatile <span class="keywordtype">void</span> **mem, <span class="keywordtype">void</span> *with, const <span class="keywordtype">void</span> *cmp); 00121 <span class="comment"></span> 00122 <span class="comment">/** @} */</span> 00123 00124 #ifdef __cplusplus 00125 } 00126 #endif 00127 00128 #endif <span class="comment">/* !APR_ATOMIC_H */</span> </pre></div><hr size="1"><address style="align: right;"><small>Generated on Sun Mar 20 19:52:26 2005 for Apache Portable Runtime by <a href="http://www.doxygen.org/index.html"> <img src="doxygen.png" alt="doxygen" align="middle" border="0"></a> 1.3.9.1 </small></address> </body> </html>