<!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/xhtml;charset=UTF-8"/>
<meta http-equiv="X-UA-Compatible" content="IE=9"/>
<meta name="generator" content="Doxygen 1.8.13"/>
<meta name="viewport" content="width=device-width, initial-scale=1"/>
<title>Apache Portable Runtime: Atomic Operations</title>
<link href="tabs.css" rel="stylesheet" type="text/css"/>
<script type="text/javascript" src="jquery.js"></script>
<script type="text/javascript" src="dynsections.js"></script>
<link href="search/search.css" rel="stylesheet" type="text/css"/>
<script type="text/javascript" src="search/searchdata.js"></script>
<script type="text/javascript" src="search/search.js"></script>
<link href="doxygen.css" rel="stylesheet" type="text/css" />
</head>
<body>
<div id="top"><!-- do not remove this div, it is closed by doxygen! -->
<div id="titlearea">
<table cellspacing="0" cellpadding="0">
<tbody>
<tr style="height: 56px;">
<td id="projectalign" style="padding-left: 0.5em;">
<div id="projectname">Apache Portable Runtime
</div>
</td>
</tr>
</tbody>
</table>
</div>
<!-- end header part -->
<!-- Generated by Doxygen 1.8.13 -->
<script type="text/javascript">
var searchBox = new SearchBox("searchBox", "search",false,'Search');
</script>
<script type="text/javascript" src="menudata.js"></script>
<script type="text/javascript" src="menu.js"></script>
<script type="text/javascript">
$(function() {
initMenu('',true,false,'search.php','Search');
$(document).ready(function() { init_search(); });
});
</script>
<div id="main-nav"></div>
</div><!-- top -->
<!-- window showing the filter options -->
<div id="MSearchSelectWindow"
onmouseover="return searchBox.OnSearchSelectShow()"
onmouseout="return searchBox.OnSearchSelectHide()"
onkeydown="return searchBox.OnSearchSelectKey(event)">
</div>
<!-- iframe showing the search results (closed by default) -->
<div id="MSearchResultsWindow">
<iframe src="javascript:void(0)" frameborder="0"
name="MSearchResults" id="MSearchResults">
</iframe>
</div>
<div class="header">
<div class="summary">
<a href="#func-members">Functions</a> </div>
<div class="headertitle">
<div class="title">Atomic Operations<div class="ingroups"><a class="el" href="group___a_p_r.html">Apache Portability Runtime library</a></div></div> </div>
</div><!--header-->
<div class="contents">
<table class="memberdecls">
<tr class="heading"><td colspan="2"><h2 class="groupheader"><a name="func-members"></a>
Functions</h2></td></tr>
<tr class="memitem:gaa89b4022de39ca4d1c2ae6715e888e97"><td class="memItemLeft" align="right" valign="top"><a class="el" href="group__apr__errno.html#gaf76ee4543247e9fb3f3546203e590a6c">apr_status_t</a> </td><td class="memItemRight" valign="bottom"><a class="el" href="group__apr__atomic.html#gaa89b4022de39ca4d1c2ae6715e888e97">apr_atomic_init</a> (<a class="el" href="group__apr__pools.html#gaf137f28edcf9a086cd6bc36c20d7cdfb">apr_pool_t</a> *p)</td></tr>
<tr class="separator:gaa89b4022de39ca4d1c2ae6715e888e97"><td class="memSeparator" colspan="2"> </td></tr>
<tr class="memitem:gafba4de90e113d26536cff48418689771"><td class="memItemLeft" align="right" valign="top">apr_uint32_t </td><td class="memItemRight" valign="bottom"><a class="el" href="group__apr__atomic.html#gafba4de90e113d26536cff48418689771">apr_atomic_read32</a> (volatile apr_uint32_t *mem)</td></tr>
<tr class="separator:gafba4de90e113d26536cff48418689771"><td class="memSeparator" colspan="2"> </td></tr>
<tr class="memitem:gac689de9df18c093f66959227359328bb"><td class="memItemLeft" align="right" valign="top">void </td><td class="memItemRight" valign="bottom"><a class="el" href="group__apr__atomic.html#gac689de9df18c093f66959227359328bb">apr_atomic_set32</a> (volatile apr_uint32_t *mem, apr_uint32_t val)</td></tr>
<tr class="separator:gac689de9df18c093f66959227359328bb"><td class="memSeparator" colspan="2"> </td></tr>
<tr class="memitem:ga3ef16e13b679710fafd5196713e17433"><td class="memItemLeft" align="right" valign="top">apr_uint32_t </td><td class="memItemRight" valign="bottom"><a class="el" href="group__apr__atomic.html#ga3ef16e13b679710fafd5196713e17433">apr_atomic_add32</a> (volatile apr_uint32_t *mem, apr_uint32_t val)</td></tr>
<tr class="separator:ga3ef16e13b679710fafd5196713e17433"><td class="memSeparator" colspan="2"> </td></tr>
<tr class="memitem:ga4603396650e844bd987f01358ccb4df1"><td class="memItemLeft" align="right" valign="top">void </td><td class="memItemRight" valign="bottom"><a class="el" href="group__apr__atomic.html#ga4603396650e844bd987f01358ccb4df1">apr_atomic_sub32</a> (volatile apr_uint32_t *mem, apr_uint32_t val)</td></tr>
<tr class="separator:ga4603396650e844bd987f01358ccb4df1"><td class="memSeparator" colspan="2"> </td></tr>
<tr class="memitem:ga4af33da5aa6493ec321af14bedfc47a9"><td class="memItemLeft" align="right" valign="top">apr_uint32_t </td><td class="memItemRight" valign="bottom"><a class="el" href="group__apr__atomic.html#ga4af33da5aa6493ec321af14bedfc47a9">apr_atomic_inc32</a> (volatile apr_uint32_t *mem)</td></tr>
<tr class="separator:ga4af33da5aa6493ec321af14bedfc47a9"><td class="memSeparator" colspan="2"> </td></tr>
<tr class="memitem:ga7a8d16335fdcd27f2baca90df35ad300"><td class="memItemLeft" align="right" valign="top">int </td><td class="memItemRight" valign="bottom"><a class="el" href="group__apr__atomic.html#ga7a8d16335fdcd27f2baca90df35ad300">apr_atomic_dec32</a> (volatile apr_uint32_t *mem)</td></tr>
<tr class="separator:ga7a8d16335fdcd27f2baca90df35ad300"><td class="memSeparator" colspan="2"> </td></tr>
<tr class="memitem:gae45c529f14f8489102382bd3fd4cce22"><td class="memItemLeft" align="right" valign="top">apr_uint32_t </td><td class="memItemRight" valign="bottom"><a class="el" href="group__apr__atomic.html#gae45c529f14f8489102382bd3fd4cce22">apr_atomic_cas32</a> (volatile apr_uint32_t *mem, apr_uint32_t with, apr_uint32_t cmp)</td></tr>
<tr class="separator:gae45c529f14f8489102382bd3fd4cce22"><td class="memSeparator" colspan="2"> </td></tr>
<tr class="memitem:ga50850e462d65e0409d5a93a6b4ec26c6"><td class="memItemLeft" align="right" valign="top">apr_uint32_t </td><td class="memItemRight" valign="bottom"><a class="el" href="group__apr__atomic.html#ga50850e462d65e0409d5a93a6b4ec26c6">apr_atomic_xchg32</a> (volatile apr_uint32_t *mem, apr_uint32_t val)</td></tr>
<tr class="separator:ga50850e462d65e0409d5a93a6b4ec26c6"><td class="memSeparator" colspan="2"> </td></tr>
<tr class="memitem:gafdd02b41cc39ade873daa2734597b0fa"><td class="memItemLeft" align="right" valign="top">void * </td><td class="memItemRight" valign="bottom"><a class="el" href="group__apr__atomic.html#gafdd02b41cc39ade873daa2734597b0fa">apr_atomic_casptr</a> (volatile void **mem, void *with, const void *cmp)</td></tr>
<tr class="separator:gafdd02b41cc39ade873daa2734597b0fa"><td class="memSeparator" colspan="2"> </td></tr>
<tr class="memitem:gaab4c1c5b8be70ded06dd31a1a4f65bf6"><td class="memItemLeft" align="right" valign="top">void * </td><td class="memItemRight" valign="bottom"><a class="el" href="group__apr__atomic.html#gaab4c1c5b8be70ded06dd31a1a4f65bf6">apr_atomic_xchgptr</a> (volatile void **mem, void *with)</td></tr>
<tr class="separator:gaab4c1c5b8be70ded06dd31a1a4f65bf6"><td class="memSeparator" colspan="2"> </td></tr>
</table>
<a name="details" id="details"></a><h2 class="groupheader">Detailed Description</h2>
<h2 class="groupheader">Function Documentation</h2>
<a id="ga3ef16e13b679710fafd5196713e17433"></a>
<h2 class="memtitle"><span class="permalink"><a href="#ga3ef16e13b679710fafd5196713e17433">◆ </a></span>apr_atomic_add32()</h2>
<div class="memitem">
<div class="memproto">
<table class="memname">
<tr>
<td class="memname">apr_uint32_t apr_atomic_add32 </td>
<td>(</td>
<td class="paramtype">volatile apr_uint32_t * </td>
<td class="paramname"><em>mem</em>, </td>
</tr>
<tr>
<td class="paramkey"></td>
<td></td>
<td class="paramtype">apr_uint32_t </td>
<td class="paramname"><em>val</em> </td>
</tr>
<tr>
<td></td>
<td>)</td>
<td></td><td></td>
</tr>
</table>
</div><div class="memdoc">
<p>atomically add 'val' to an apr_uint32_t </p><dl class="params"><dt>Parameters</dt><dd>
<table class="params">
<tr><td class="paramname">mem</td><td>pointer to the object </td></tr>
<tr><td class="paramname">val</td><td>amount to add </td></tr>
</table>
</dd>
</dl>
<dl class="section return"><dt>Returns</dt><dd>old value pointed to by mem </dd></dl>
</div>
</div>
<a id="gae45c529f14f8489102382bd3fd4cce22"></a>
<h2 class="memtitle"><span class="permalink"><a href="#gae45c529f14f8489102382bd3fd4cce22">◆ </a></span>apr_atomic_cas32()</h2>
<div class="memitem">
<div class="memproto">
<table class="memname">
<tr>
<td class="memname">apr_uint32_t apr_atomic_cas32 </td>
<td>(</td>
<td class="paramtype">volatile apr_uint32_t * </td>
<td class="paramname"><em>mem</em>, </td>
</tr>
<tr>
<td class="paramkey"></td>
<td></td>
<td class="paramtype">apr_uint32_t </td>
<td class="paramname"><em>with</em>, </td>
</tr>
<tr>
<td class="paramkey"></td>
<td></td>
<td class="paramtype">apr_uint32_t </td>
<td class="paramname"><em>cmp</em> </td>
</tr>
<tr>
<td></td>
<td>)</td>
<td></td><td></td>
</tr>
</table>
</div><div class="memdoc">
<p>compare an apr_uint32_t's value with 'cmp'. If they are the same swap the value with 'with' </p><dl class="params"><dt>Parameters</dt><dd>
<table class="params">
<tr><td class="paramname">mem</td><td>pointer to the value </td></tr>
<tr><td class="paramname">with</td><td>what to swap it with </td></tr>
<tr><td class="paramname">cmp</td><td>the value to compare it to </td></tr>
</table>
</dd>
</dl>
<dl class="section return"><dt>Returns</dt><dd>the old value of *mem </dd></dl>
</div>
</div>
<a id="gafdd02b41cc39ade873daa2734597b0fa"></a>
<h2 class="memtitle"><span class="permalink"><a href="#gafdd02b41cc39ade873daa2734597b0fa">◆ </a></span>apr_atomic_casptr()</h2>
<div class="memitem">
<div class="memproto">
<table class="memname">
<tr>
<td class="memname">void* apr_atomic_casptr </td>
<td>(</td>
<td class="paramtype">volatile void ** </td>
<td class="paramname"><em>mem</em>, </td>
</tr>
<tr>
<td class="paramkey"></td>
<td></td>
<td class="paramtype">void * </td>
<td class="paramname"><em>with</em>, </td>
</tr>
<tr>
<td class="paramkey"></td>
<td></td>
<td class="paramtype">const void * </td>
<td class="paramname"><em>cmp</em> </td>
</tr>
<tr>
<td></td>
<td>)</td>
<td></td><td></td>
</tr>
</table>
</div><div class="memdoc">
<p>compare the pointer's value with cmp. If they are the same swap the value with 'with' </p><dl class="params"><dt>Parameters</dt><dd>
<table class="params">
<tr><td class="paramname">mem</td><td>pointer to the pointer </td></tr>
<tr><td class="paramname">with</td><td>what to swap it with </td></tr>
<tr><td class="paramname">cmp</td><td>the value to compare it to </td></tr>
</table>
</dd>
</dl>
<dl class="section return"><dt>Returns</dt><dd>the old value of the pointer </dd></dl>
</div>
</div>
<a id="ga7a8d16335fdcd27f2baca90df35ad300"></a>
<h2 class="memtitle"><span class="permalink"><a href="#ga7a8d16335fdcd27f2baca90df35ad300">◆ </a></span>apr_atomic_dec32()</h2>
<div class="memitem">
<div class="memproto">
<table class="memname">
<tr>
<td class="memname">int apr_atomic_dec32 </td>
<td>(</td>
<td class="paramtype">volatile apr_uint32_t * </td>
<td class="paramname"><em>mem</em></td><td>)</td>
<td></td>
</tr>
</table>
</div><div class="memdoc">
<p>atomically decrement an apr_uint32_t by 1 </p><dl class="params"><dt>Parameters</dt><dd>
<table class="params">
<tr><td class="paramname">mem</td><td>pointer to the atomic value </td></tr>
</table>
</dd>
</dl>
<dl class="section return"><dt>Returns</dt><dd>zero if the value becomes zero on decrement, otherwise non-zero </dd></dl>
</div>
</div>
<a id="ga4af33da5aa6493ec321af14bedfc47a9"></a>
<h2 class="memtitle"><span class="permalink"><a href="#ga4af33da5aa6493ec321af14bedfc47a9">◆ </a></span>apr_atomic_inc32()</h2>
<div class="memitem">
<div class="memproto">
<table class="memname">
<tr>
<td class="memname">apr_uint32_t apr_atomic_inc32 </td>
<td>(</td>
<td class="paramtype">volatile apr_uint32_t * </td>
<td class="paramname"><em>mem</em></td><td>)</td>
<td></td>
</tr>
</table>
</div><div class="memdoc">
<p>atomically increment an apr_uint32_t by 1 </p><dl class="params"><dt>Parameters</dt><dd>
<table class="params">
<tr><td class="paramname">mem</td><td>pointer to the object </td></tr>
</table>
</dd>
</dl>
<dl class="section return"><dt>Returns</dt><dd>old value pointed to by mem </dd></dl>
</div>
</div>
<a id="gaa89b4022de39ca4d1c2ae6715e888e97"></a>
<h2 class="memtitle"><span class="permalink"><a href="#gaa89b4022de39ca4d1c2ae6715e888e97">◆ </a></span>apr_atomic_init()</h2>
<div class="memitem">
<div class="memproto">
<table class="memname">
<tr>
<td class="memname"><a class="el" href="group__apr__errno.html#gaf76ee4543247e9fb3f3546203e590a6c">apr_status_t</a> apr_atomic_init </td>
<td>(</td>
<td class="paramtype"><a class="el" href="group__apr__pools.html#gaf137f28edcf9a086cd6bc36c20d7cdfb">apr_pool_t</a> * </td>
<td class="paramname"><em>p</em></td><td>)</td>
<td></td>
</tr>
</table>
</div><div class="memdoc">
<p>this function is required on some platforms to initialize the atomic operation's internal structures </p><dl class="params"><dt>Parameters</dt><dd>
<table class="params">
<tr><td class="paramname">p</td><td>pool </td></tr>
</table>
</dd>
</dl>
<dl class="section return"><dt>Returns</dt><dd>APR_SUCCESS on successful completion </dd></dl>
<dl class="section remark"><dt>Remarks</dt><dd>Programs do NOT need to call this directly. APR will call this automatically from apr_initialize. </dd></dl>
</div>
</div>
<a id="gafba4de90e113d26536cff48418689771"></a>
<h2 class="memtitle"><span class="permalink"><a href="#gafba4de90e113d26536cff48418689771">◆ </a></span>apr_atomic_read32()</h2>
<div class="memitem">
<div class="memproto">
<table class="memname">
<tr>
<td class="memname">apr_uint32_t apr_atomic_read32 </td>
<td>(</td>
<td class="paramtype">volatile apr_uint32_t * </td>
<td class="paramname"><em>mem</em></td><td>)</td>
<td></td>
</tr>
</table>
</div><div class="memdoc">
<p>atomically read an apr_uint32_t from memory </p><dl class="params"><dt>Parameters</dt><dd>
<table class="params">
<tr><td class="paramname">mem</td><td>the pointer </td></tr>
</table>
</dd>
</dl>
</div>
</div>
<a id="gac689de9df18c093f66959227359328bb"></a>
<h2 class="memtitle"><span class="permalink"><a href="#gac689de9df18c093f66959227359328bb">◆ </a></span>apr_atomic_set32()</h2>
<div class="memitem">
<div class="memproto">
<table class="memname">
<tr>
<td class="memname">void apr_atomic_set32 </td>
<td>(</td>
<td class="paramtype">volatile apr_uint32_t * </td>
<td class="paramname"><em>mem</em>, </td>
</tr>
<tr>
<td class="paramkey"></td>
<td></td>
<td class="paramtype">apr_uint32_t </td>
<td class="paramname"><em>val</em> </td>
</tr>
<tr>
<td></td>
<td>)</td>
<td></td><td></td>
</tr>
</table>
</div><div class="memdoc">
<p>atomically set an apr_uint32_t in memory </p><dl class="params"><dt>Parameters</dt><dd>
<table class="params">
<tr><td class="paramname">mem</td><td>pointer to the object </td></tr>
<tr><td class="paramname">val</td><td>value that the object will assume </td></tr>
</table>
</dd>
</dl>
</div>
</div>
<a id="ga4603396650e844bd987f01358ccb4df1"></a>
<h2 class="memtitle"><span class="permalink"><a href="#ga4603396650e844bd987f01358ccb4df1">◆ </a></span>apr_atomic_sub32()</h2>
<div class="memitem">
<div class="memproto">
<table class="memname">
<tr>
<td class="memname">void apr_atomic_sub32 </td>
<td>(</td>
<td class="paramtype">volatile apr_uint32_t * </td>
<td class="paramname"><em>mem</em>, </td>
</tr>
<tr>
<td class="paramkey"></td>
<td></td>
<td class="paramtype">apr_uint32_t </td>
<td class="paramname"><em>val</em> </td>
</tr>
<tr>
<td></td>
<td>)</td>
<td></td><td></td>
</tr>
</table>
</div><div class="memdoc">
<p>atomically subtract 'val' from an apr_uint32_t </p><dl class="params"><dt>Parameters</dt><dd>
<table class="params">
<tr><td class="paramname">mem</td><td>pointer to the object </td></tr>
<tr><td class="paramname">val</td><td>amount to subtract </td></tr>
</table>
</dd>
</dl>
</div>
</div>
<a id="ga50850e462d65e0409d5a93a6b4ec26c6"></a>
<h2 class="memtitle"><span class="permalink"><a href="#ga50850e462d65e0409d5a93a6b4ec26c6">◆ </a></span>apr_atomic_xchg32()</h2>
<div class="memitem">
<div class="memproto">
<table class="memname">
<tr>
<td class="memname">apr_uint32_t apr_atomic_xchg32 </td>
<td>(</td>
<td class="paramtype">volatile apr_uint32_t * </td>
<td class="paramname"><em>mem</em>, </td>
</tr>
<tr>
<td class="paramkey"></td>
<td></td>
<td class="paramtype">apr_uint32_t </td>
<td class="paramname"><em>val</em> </td>
</tr>
<tr>
<td></td>
<td>)</td>
<td></td><td></td>
</tr>
</table>
</div><div class="memdoc">
<p>exchange an apr_uint32_t's value with 'val'. </p><dl class="params"><dt>Parameters</dt><dd>
<table class="params">
<tr><td class="paramname">mem</td><td>pointer to the value </td></tr>
<tr><td class="paramname">val</td><td>what to swap it with </td></tr>
</table>
</dd>
</dl>
<dl class="section return"><dt>Returns</dt><dd>the old value of *mem </dd></dl>
</div>
</div>
<a id="gaab4c1c5b8be70ded06dd31a1a4f65bf6"></a>
<h2 class="memtitle"><span class="permalink"><a href="#gaab4c1c5b8be70ded06dd31a1a4f65bf6">◆ </a></span>apr_atomic_xchgptr()</h2>
<div class="memitem">
<div class="memproto">
<table class="memname">
<tr>
<td class="memname">void* apr_atomic_xchgptr </td>
<td>(</td>
<td class="paramtype">volatile void ** </td>
<td class="paramname"><em>mem</em>, </td>
</tr>
<tr>
<td class="paramkey"></td>
<td></td>
<td class="paramtype">void * </td>
<td class="paramname"><em>with</em> </td>
</tr>
<tr>
<td></td>
<td>)</td>
<td></td><td></td>
</tr>
</table>
</div><div class="memdoc">
<p>exchange a pair of pointer values </p><dl class="params"><dt>Parameters</dt><dd>
<table class="params">
<tr><td class="paramname">mem</td><td>pointer to the pointer </td></tr>
<tr><td class="paramname">with</td><td>what to swap it with </td></tr>
</table>
</dd>
</dl>
<dl class="section return"><dt>Returns</dt><dd>the old value of the pointer </dd></dl>
</div>
</div>
</div><!-- contents -->
<!-- start footer part -->
<hr class="footer"/><address class="footer"><small>
Generated by  <a href="http://www.doxygen.org/index.html">
<img class="footer" src="doxygen.png" alt="doxygen"/>
</a> 1.8.13
</small></address>
</body>
</html>
