blob: cfc501ebd232bf9c78965b3c89f9cf3918812330 [file] [log] [blame]
<!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"/>
<title>Event Flags</title>
<title>CMSIS-RTOS2: Event Flags</title>
<link href="tabs.css" rel="stylesheet" type="text/css"/>
<link href="cmsis.css" rel="stylesheet" type="text/css" />
<script type="text/javascript" src="jquery.js"></script>
<script type="text/javascript" src="dynsections.js"></script>
<script type="text/javascript" src="printComponentTabs.js"></script>
<link href="navtree.css" rel="stylesheet" type="text/css"/>
<script type="text/javascript" src="resize.js"></script>
<script type="text/javascript" src="navtree.js"></script>
<script type="text/javascript">
$(document).ready(initResizable);
$(window).load(resizeHeight);
</script>
<link href="search/search.css" rel="stylesheet" type="text/css"/>
<script type="text/javascript" src="search/search.js"></script>
<script type="text/javascript">
$(document).ready(function() { searchBox.OnSelectItem(0); });
</script>
</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: 46px;">
<td id="projectlogo"><img alt="Logo" src="CMSIS_Logo_Final.png"/></td>
<td style="padding-left: 0.5em;">
<div id="projectname">CMSIS-RTOS2
&#160;<span id="projectnumber">Version 2.1.3</span>
</div>
<div id="projectbrief">Real-Time Operating System: API and RTX Reference Implementation</div>
</td>
</tr>
</tbody>
</table>
</div>
<!-- end header part -->
<div id="CMSISnav" class="tabs1">
<ul class="tablist">
<script type="text/javascript">
<!--
writeComponentTabs.call(this);
//-->
</script>
</ul>
</div>
<!-- Generated by Doxygen 1.8.6 -->
<script type="text/javascript">
var searchBox = new SearchBox("searchBox", "search",false,'Search');
</script>
<div id="navrow1" class="tabs">
<ul class="tablist">
<li><a href="index.html"><span>Main&#160;Page</span></a></li>
<li><a href="pages.html"><span>Usage&#160;and&#160;Description</span></a></li>
<li><a href="modules.html"><span>Reference</span></a></li>
<li>
<div id="MSearchBox" class="MSearchBoxInactive">
<span class="left">
<img id="MSearchSelect" src="search/mag_sel.png"
onmouseover="return searchBox.OnSearchSelectShow()"
onmouseout="return searchBox.OnSearchSelectHide()"
alt=""/>
<input type="text" id="MSearchField" value="Search" accesskey="S"
onfocus="searchBox.OnSearchFieldFocus(true)"
onblur="searchBox.OnSearchFieldFocus(false)"
onkeyup="searchBox.OnSearchFieldChange(event)"/>
</span><span class="right">
<a id="MSearchClose" href="javascript:searchBox.CloseResultsWindow()"><img id="MSearchCloseImg" border="0" src="search/close.png" alt=""/></a>
</span>
</div>
</li>
</ul>
</div>
</div><!-- top -->
<div id="side-nav" class="ui-resizable side-nav-resizable">
<div id="nav-tree">
<div id="nav-tree-contents">
<div id="nav-sync" class="sync"></div>
</div>
</div>
<div id="splitbar" style="-moz-user-select:none;"
class="ui-resizable-handle">
</div>
</div>
<script type="text/javascript">
$(document).ready(function(){initNavTree('group__CMSIS__RTOS__EventFlags.html','');});
</script>
<div id="doc-content">
<!-- window showing the filter options -->
<div id="MSearchSelectWindow"
onmouseover="return searchBox.OnSearchSelectShow()"
onmouseout="return searchBox.OnSearchSelectHide()"
onkeydown="return searchBox.OnSearchSelectKey(event)">
<a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(0)"><span class="SelectionMark">&#160;</span>All</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(1)"><span class="SelectionMark">&#160;</span>Data Structures</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(2)"><span class="SelectionMark">&#160;</span>Files</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(3)"><span class="SelectionMark">&#160;</span>Functions</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(4)"><span class="SelectionMark">&#160;</span>Variables</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(5)"><span class="SelectionMark">&#160;</span>Typedefs</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(6)"><span class="SelectionMark">&#160;</span>Enumerations</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(7)"><span class="SelectionMark">&#160;</span>Enumerator</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(8)"><span class="SelectionMark">&#160;</span>Macros</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(9)"><span class="SelectionMark">&#160;</span>Groups</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(10)"><span class="SelectionMark">&#160;</span>Pages</a></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="#nested-classes">Data Structures</a> &#124;
<a href="#typedef-members">Typedefs</a> &#124;
<a href="#func-members">Functions</a> </div>
<div class="headertitle">
<div class="title">Event Flags<div class="ingroups"><a class="el" href="group__CMSIS__RTOS.html">CMSIS-RTOS API v2</a></div></div> </div>
</div><!--header-->
<div class="contents">
<p>Synchronize threads using event flags.
<a href="#details">More...</a></p>
<table class="memberdecls">
<tr class="heading"><td colspan="2"><h2 class="groupheader"><a name="nested-classes"></a>
Data Structures</h2></td></tr>
<tr class="memitem:structosEventFlagsAttr__t"><td class="memItemLeft" align="right" valign="top">struct &#160;</td><td class="memItemRight" valign="bottom"><a class="el" href="group__CMSIS__RTOS__EventFlags.html#structosEventFlagsAttr__t">osEventFlagsAttr_t</a></td></tr>
<tr class="memdesc:structosEventFlagsAttr__t"><td class="mdescLeft">&#160;</td><td class="mdescRight">Attributes structure for event flags. <a href="group__CMSIS__RTOS__EventFlags.html#structosEventFlagsAttr__t">More...</a><br/></td></tr>
<tr class="separator:structosEventFlagsAttr__t"><td class="memSeparator" colspan="2">&#160;</td></tr>
</table><table class="memberdecls">
<tr class="heading"><td colspan="2"><h2 class="groupheader"><a name="typedef-members"></a>
Typedefs</h2></td></tr>
<tr class="memitem:gafdbab933146d6d81d7cca7287e267a50"><td class="memItemLeft" align="right" valign="top">typedef void *&#160;</td><td class="memItemRight" valign="bottom"><a class="el" href="group__CMSIS__RTOS__EventFlags.html#gafdbab933146d6d81d7cca7287e267a50">osEventFlagsId_t</a></td></tr>
<tr class="separator:gafdbab933146d6d81d7cca7287e267a50"><td class="memSeparator" colspan="2">&#160;</td></tr>
</table><table class="memberdecls">
<tr class="heading"><td colspan="2"><h2 class="groupheader"><a name="func-members"></a>
Functions</h2></td></tr>
<tr class="memitem:gab14b1caeb12ffa42cce1bfe889cd07df"><td class="memItemLeft" align="right" valign="top"><a class="el" href="group__CMSIS__RTOS__EventFlags.html#gafdbab933146d6d81d7cca7287e267a50">osEventFlagsId_t</a>&#160;</td><td class="memItemRight" valign="bottom"><a class="el" href="group__CMSIS__RTOS__EventFlags.html#gab14b1caeb12ffa42cce1bfe889cd07df">osEventFlagsNew</a> (const <a class="el" href="group__CMSIS__RTOS__EventFlags.html#structosEventFlagsAttr__t">osEventFlagsAttr_t</a> *attr)</td></tr>
<tr class="memdesc:gab14b1caeb12ffa42cce1bfe889cd07df"><td class="mdescLeft">&#160;</td><td class="mdescRight">Create and Initialize an Event Flags object. <a href="#gab14b1caeb12ffa42cce1bfe889cd07df">More...</a><br/></td></tr>
<tr class="separator:gab14b1caeb12ffa42cce1bfe889cd07df"><td class="memSeparator" colspan="2">&#160;</td></tr>
<tr class="memitem:ga33b71d14cecf90b4e72639dd19f23a5e"><td class="memItemLeft" align="right" valign="top">uint32_t&#160;</td><td class="memItemRight" valign="bottom"><a class="el" href="group__CMSIS__RTOS__EventFlags.html#ga33b71d14cecf90b4e72639dd19f23a5e">osEventFlagsSet</a> (<a class="el" href="group__CMSIS__RTOS__EventFlags.html#gafdbab933146d6d81d7cca7287e267a50">osEventFlagsId_t</a> ef_id, uint32_t flags)</td></tr>
<tr class="memdesc:ga33b71d14cecf90b4e72639dd19f23a5e"><td class="mdescLeft">&#160;</td><td class="mdescRight">Set the specified Event Flags. <a href="#ga33b71d14cecf90b4e72639dd19f23a5e">More...</a><br/></td></tr>
<tr class="separator:ga33b71d14cecf90b4e72639dd19f23a5e"><td class="memSeparator" colspan="2">&#160;</td></tr>
<tr class="memitem:ga93bf258ca0007c6641fbe8e4f2b8a1e5"><td class="memItemLeft" align="right" valign="top">uint32_t&#160;</td><td class="memItemRight" valign="bottom"><a class="el" href="group__CMSIS__RTOS__EventFlags.html#ga93bf258ca0007c6641fbe8e4f2b8a1e5">osEventFlagsClear</a> (<a class="el" href="group__CMSIS__RTOS__EventFlags.html#gafdbab933146d6d81d7cca7287e267a50">osEventFlagsId_t</a> ef_id, uint32_t flags)</td></tr>
<tr class="memdesc:ga93bf258ca0007c6641fbe8e4f2b8a1e5"><td class="mdescLeft">&#160;</td><td class="mdescRight">Clear the specified Event Flags. <a href="#ga93bf258ca0007c6641fbe8e4f2b8a1e5">More...</a><br/></td></tr>
<tr class="separator:ga93bf258ca0007c6641fbe8e4f2b8a1e5"><td class="memSeparator" colspan="2">&#160;</td></tr>
<tr class="memitem:ga8bda3185f46bfd278cea8a6cf357677d"><td class="memItemLeft" align="right" valign="top">uint32_t&#160;</td><td class="memItemRight" valign="bottom"><a class="el" href="group__CMSIS__RTOS__EventFlags.html#ga8bda3185f46bfd278cea8a6cf357677d">osEventFlagsGet</a> (<a class="el" href="group__CMSIS__RTOS__EventFlags.html#gafdbab933146d6d81d7cca7287e267a50">osEventFlagsId_t</a> ef_id)</td></tr>
<tr class="memdesc:ga8bda3185f46bfd278cea8a6cf357677d"><td class="mdescLeft">&#160;</td><td class="mdescRight">Get the current Event Flags. <a href="#ga8bda3185f46bfd278cea8a6cf357677d">More...</a><br/></td></tr>
<tr class="separator:ga8bda3185f46bfd278cea8a6cf357677d"><td class="memSeparator" colspan="2">&#160;</td></tr>
<tr class="memitem:ga52acb34a8322e58020227344fe662b4e"><td class="memItemLeft" align="right" valign="top">uint32_t&#160;</td><td class="memItemRight" valign="bottom"><a class="el" href="group__CMSIS__RTOS__EventFlags.html#ga52acb34a8322e58020227344fe662b4e">osEventFlagsWait</a> (<a class="el" href="group__CMSIS__RTOS__EventFlags.html#gafdbab933146d6d81d7cca7287e267a50">osEventFlagsId_t</a> ef_id, uint32_t flags, uint32_t options, uint32_t timeout)</td></tr>
<tr class="memdesc:ga52acb34a8322e58020227344fe662b4e"><td class="mdescLeft">&#160;</td><td class="mdescRight">Wait for one or more Event Flags to become signaled. <a href="#ga52acb34a8322e58020227344fe662b4e">More...</a><br/></td></tr>
<tr class="separator:ga52acb34a8322e58020227344fe662b4e"><td class="memSeparator" colspan="2">&#160;</td></tr>
<tr class="memitem:ga7c4acf2fb0d506ec82905dee53fb5435"><td class="memItemLeft" align="right" valign="top"><a class="el" href="group__CMSIS__RTOS__Definitions.html#ga6c0dbe6069e4e7f47bb4cd32ae2b813e">osStatus_t</a>&#160;</td><td class="memItemRight" valign="bottom"><a class="el" href="group__CMSIS__RTOS__EventFlags.html#ga7c4acf2fb0d506ec82905dee53fb5435">osEventFlagsDelete</a> (<a class="el" href="group__CMSIS__RTOS__EventFlags.html#gafdbab933146d6d81d7cca7287e267a50">osEventFlagsId_t</a> ef_id)</td></tr>
<tr class="memdesc:ga7c4acf2fb0d506ec82905dee53fb5435"><td class="mdescLeft">&#160;</td><td class="mdescRight">Delete an Event Flags object. <a href="#ga7c4acf2fb0d506ec82905dee53fb5435">More...</a><br/></td></tr>
<tr class="separator:ga7c4acf2fb0d506ec82905dee53fb5435"><td class="memSeparator" colspan="2">&#160;</td></tr>
<tr class="memitem:ga59f4ddf0ee8c395b1672bb978d1cfc88"><td class="memItemLeft" align="right" valign="top">const char *&#160;</td><td class="memItemRight" valign="bottom"><a class="el" href="group__CMSIS__RTOS__EventFlags.html#ga59f4ddf0ee8c395b1672bb978d1cfc88">osEventFlagsGetName</a> (<a class="el" href="group__CMSIS__RTOS__EventFlags.html#gafdbab933146d6d81d7cca7287e267a50">osEventFlagsId_t</a> ef_id)</td></tr>
<tr class="memdesc:ga59f4ddf0ee8c395b1672bb978d1cfc88"><td class="mdescLeft">&#160;</td><td class="mdescRight">Get name of an Event Flags object. <a href="#ga59f4ddf0ee8c395b1672bb978d1cfc88">More...</a><br/></td></tr>
<tr class="separator:ga59f4ddf0ee8c395b1672bb978d1cfc88"><td class="memSeparator" colspan="2">&#160;</td></tr>
</table>
<a name="details" id="details"></a><h2 class="groupheader">Description</h2>
<p>The event flags management functions in CMSIS-RTOS allow you to control or wait for event flags. Each signal has up to 31 event flags.</p>
<p>A thread</p>
<ul>
<li>can wait for event flags to be set (using <a class="el" href="group__CMSIS__RTOS__EventFlags.html#ga52acb34a8322e58020227344fe662b4e">osEventFlagsWait</a>). Using this function, it enters the <a class="el" href="group__CMSIS__RTOS__ThreadMgmt.html#ThreadStates">BLOCKED</a> state.</li>
<li>may set one or more flags in any other given thread (using <a class="el" href="group__CMSIS__RTOS__EventFlags.html#ga33b71d14cecf90b4e72639dd19f23a5e">osEventFlagsSet</a>).</li>
<li>may clear its own signals or the signals of other threads (using <a class="el" href="group__CMSIS__RTOS__EventFlags.html#ga93bf258ca0007c6641fbe8e4f2b8a1e5">osEventFlagsClear</a>).</li>
</ul>
<p>When a thread wakes up and resumes execution, its signal flags are automatically cleared (unless event flags option <a class="el" href="group__CMSIS__RTOS__Definitions.html#gaade844a42237d8c37569d4d9b16b9f1c">osFlagsNoClear</a> is specified).</p>
<dl class="section note"><dt>Note</dt><dd>The functions <a class="el" href="group__CMSIS__RTOS__EventFlags.html#ga33b71d14cecf90b4e72639dd19f23a5e">osEventFlagsSet</a>, <a class="el" href="group__CMSIS__RTOS__EventFlags.html#ga93bf258ca0007c6641fbe8e4f2b8a1e5">osEventFlagsClear</a>, <a class="el" href="group__CMSIS__RTOS__EventFlags.html#ga8bda3185f46bfd278cea8a6cf357677d">osEventFlagsGet</a>, and <a class="el" href="group__CMSIS__RTOS__EventFlags.html#ga52acb34a8322e58020227344fe662b4e">osEventFlagsWait</a> can be called from <a class="el" href="theory_of_operation.html#CMSIS_RTOS_ISR_Calls">Interrupt Service Routines</a>. </dd>
<dd>
Refer to <a class="el" href="config_rtx5.html#eventFlagsConfig">Event Flags Configuration</a> for RTX5 configuration options.</dd></dl>
<h2>Working with Events </h2>
<p>Here is a simple example that shows how two thread can communicate with each others using event flags:</p>
<div class="image">
<img src="simple_signal.png" alt="simple_signal.png"/>
<div class="caption">
Simple event communication</div></div>
<p> The following steps are required to use event flags:</p>
<ol type="1">
<li>In the thread that is supposed to send a event with id sig1_id, call the set function: <div class="fragment"><div class="line"><a class="code" href="group__CMSIS__RTOS__Wait.html#gaf6055a51390ef65b6b6edc28bf47322e">osDelay</a>(1000U); <span class="comment">// wait for 1 second</span></div>
<div class="line"><a class="code" href="group__CMSIS__RTOS__EventFlags.html#ga33b71d14cecf90b4e72639dd19f23a5e">osEventFlagsSet</a>(sig1_id, 0x0001U); <span class="comment">// set the flag 0x0001U for event sig1_id</span></div>
</div><!-- fragment --></li>
<li>In another thread (or threads) that are supposed to wait for the event, call the wait function: <div class="fragment"><div class="line"><a class="code" href="group__CMSIS__RTOS__EventFlags.html#ga52acb34a8322e58020227344fe662b4e">osEventFlagsWait</a>(sig1_id, 0x0001U, NULL, <a class="code" href="group__CMSIS__RTOS__Definitions.html#ga9eb9a7a797a42e4b55eb171ecc609ddb">osWaitForever</a>); <span class="comment">// wait forever for any flag</span></div>
</div><!-- fragment --></li>
</ol>
<p>The following complete example code can be directly used with the "CMSIS-RTOS2 main template" and is also provided as a stand-alone template for RTX5:</p>
<p><b>Code Example</b> </p>
<div class="fragment"><div class="line"><span class="preprocessor">#include &quot;<a class="code" href="cmsis__os2_8h.html">cmsis_os2.h</a>&quot;</span> <span class="comment">// CMSIS RTOS header file</span></div>
<div class="line"> </div>
<div class="line"><span class="comment">/*----------------------------------------------------------------------------</span></div>
<div class="line"><span class="comment"> * Event Flags creation &amp; usage</span></div>
<div class="line"><span class="comment"> *---------------------------------------------------------------------------*/</span></div>
<div class="line"> </div>
<div class="line"><span class="preprocessor">#define FLAGS_MSK1 0x00000001U</span></div>
<div class="line"><span class="preprocessor"></span> </div>
<div class="line"><a class="code" href="group__CMSIS__RTOS__EventFlags.html#gafdbab933146d6d81d7cca7287e267a50">osEventFlagsId_t</a> evt_id; <span class="comment">// event flags id</span></div>
<div class="line"> </div>
<div class="line"><a class="code" href="group__CMSIS__RTOS__ThreadMgmt.html#gaa6c32fe2a3e0a2e01f212d55b02e51c7">osThreadId_t</a> tid_Thread_EventSender; <span class="comment">// thread id 1</span></div>
<div class="line"><a class="code" href="group__CMSIS__RTOS__ThreadMgmt.html#gaa6c32fe2a3e0a2e01f212d55b02e51c7">osThreadId_t</a> tid_Thread_EventReceiver; <span class="comment">// thread id 2</span></div>
<div class="line"> </div>
<div class="line"><span class="keywordtype">void</span> Thread_EventSender (<span class="keywordtype">void</span> *argument); <span class="comment">// thread function 1</span></div>
<div class="line"><span class="keywordtype">void</span> Thread_EventReceiver (<span class="keywordtype">void</span> *argument); <span class="comment">// thread function 2</span></div>
<div class="line"> </div>
<div class="line"><span class="keywordtype">int</span> Init_Events (<span class="keywordtype">void</span>) {</div>
<div class="line"> </div>
<div class="line"> evt_id = <a class="code" href="group__CMSIS__RTOS__EventFlags.html#gab14b1caeb12ffa42cce1bfe889cd07df">osEventFlagsNew</a>(NULL);</div>
<div class="line"> <span class="keywordflow">if</span> (evt_id == NULL) {</div>
<div class="line"> ; <span class="comment">// Event Flags object not created, handle failure</span></div>
<div class="line"> }</div>
<div class="line"> </div>
<div class="line"> tid_Thread_EventSender = <a class="code" href="group__CMSIS__RTOS__ThreadMgmt.html#ga48d68b8666d99d28fa646ee1d2182b8f">osThreadNew</a>(Thread_EventSender, NULL, NULL);</div>
<div class="line"> <span class="keywordflow">if</span> (tid_Thread_EventSender == NULL) {</div>
<div class="line"> <span class="keywordflow">return</span>(-1);</div>
<div class="line"> }</div>
<div class="line"> tid_Thread_EventReceiver = <a class="code" href="group__CMSIS__RTOS__ThreadMgmt.html#ga48d68b8666d99d28fa646ee1d2182b8f">osThreadNew</a>(Thread_EventReceiver, NULL, NULL);</div>
<div class="line"> <span class="keywordflow">if</span> (tid_Thread_EventReceiver == NULL) {</div>
<div class="line"> <span class="keywordflow">return</span>(-1);</div>
<div class="line"> }</div>
<div class="line"></div>
<div class="line"> <span class="keywordflow">return</span>(0);</div>
<div class="line">}</div>
<div class="line"> </div>
<div class="line"><span class="keywordtype">void</span> Thread_EventSender (<span class="keywordtype">void</span> *argument) {</div>
<div class="line"> </div>
<div class="line"> <span class="keywordflow">while</span> (1) { </div>
<div class="line"> <a class="code" href="group__CMSIS__RTOS__EventFlags.html#ga33b71d14cecf90b4e72639dd19f23a5e">osEventFlagsSet</a>(evt_id, FLAGS_MSK1);</div>
<div class="line"> <a class="code" href="group__CMSIS__RTOS__ThreadMgmt.html#gad01c7ec26535b1de6b018bb9466720e2">osThreadYield</a>(); <span class="comment">// suspend thread</span></div>
<div class="line"> }</div>
<div class="line">}</div>
<div class="line"> </div>
<div class="line"><span class="keywordtype">void</span> Thread_EventReceiver (<span class="keywordtype">void</span> *argument) {</div>
<div class="line"> uint32_t flags;</div>
<div class="line"> </div>
<div class="line"> <span class="keywordflow">while</span> (1) {</div>
<div class="line"> flags = <a class="code" href="group__CMSIS__RTOS__EventFlags.html#ga52acb34a8322e58020227344fe662b4e">osEventFlagsWait</a>(evt_id, FLAGS_MSK1, <a class="code" href="group__CMSIS__RTOS__Definitions.html#ga18e63587b8450d5b8798b6f6ec04e012">osFlagsWaitAny</a>, <a class="code" href="group__CMSIS__RTOS__Definitions.html#ga9eb9a7a797a42e4b55eb171ecc609ddb">osWaitForever</a>);</div>
<div class="line"> <span class="comment">//handle event</span></div>
<div class="line"> }</div>
<div class="line">}</div>
</div><!-- fragment --> <hr/><h2 class="groupheader">Data Structure Documentation</h2>
<a name="structosEventFlagsAttr__t" id="structosEventFlagsAttr__t"></a>
<div class="memitem">
<div class="memproto">
<table class="memname">
<tr>
<td class="memname">struct osEventFlagsAttr_t</td>
</tr>
</table>
</div><div class="memdoc">
<div class="textblock"><p>Attributes to configure an event flag set.</p>
<p>Refer to <a class="el" href="group__CMSIS__RTOS__MemoryMgmt.html">Memory Management</a> for details about usage of</p>
<ul>
<li><a class="el" href="group__CMSIS__RTOS__EventFlags.html#a1e100dc33d403841ed3c344e3397868e" title="memory for control block ">osEventFlagsAttr_t::cb_mem</a></li>
<li><a class="el" href="group__CMSIS__RTOS__EventFlags.html#aa55a4335d12dc2785dc00fdc292d1159" title="size of provided memory for control block ">osEventFlagsAttr_t::cb_size</a> </li>
</ul>
</div><table class="fieldtable">
<tr><th colspan="3">Data Fields</th></tr>
<tr><td class="fieldtype">
<a class="anchor" id="ab74e6bf80237ddc4109968cedc58c151"></a>const char *</td>
<td class="fieldname">
name</td>
<td class="fielddoc">
name of the event flags <p>Pointer to a constant string with a human readable name (displayed during debugging) of the event flag object.</p>
<p>Default: <span class="XML-Token">NULL</span> no name specified. </p>
</td></tr>
<tr><td class="fieldtype">
<a class="anchor" id="a6e93b49cb79c12f768d72580c7731f30"></a>uint32_t</td>
<td class="fieldname">
attr_bits</td>
<td class="fielddoc">
attribute bits <p>Reserved for future use (must be set to '0' for future compatibility). </p>
</td></tr>
<tr><td class="fieldtype">
<a class="anchor" id="a1e100dc33d403841ed3c344e3397868e"></a>void *</td>
<td class="fieldname">
cb_mem</td>
<td class="fielddoc">
memory for control block <p>Pointer to a memory for the event flag control block object. Refer to <a class="el" href="theory_of_operation.html#StaticObjectMemory">Static Object Memory</a> for more information.</p>
<p>Default: <span class="XML-Token">NULL</span> to use <a class="el" href="group__CMSIS__RTOS__MemoryMgmt.html#CMSIS_RTOS_MemoryMgmt_Automatic">Automatic Dynamic Allocation</a> for the event flag control block. </p>
</td></tr>
<tr><td class="fieldtype">
<a class="anchor" id="aa55a4335d12dc2785dc00fdc292d1159"></a>uint32_t</td>
<td class="fieldname">
cb_size</td>
<td class="fielddoc">
size of provided memory for control block <p>The size (in bytes) of memory block passed with <a class="el" href="group__CMSIS__RTOS__EventFlags.html#a1e100dc33d403841ed3c344e3397868e">cb_mem</a>. For RTX, the minimum value is defined with <a class="el" href="group__rtx5__specific__defines.html#ga68100c8c44931f03547973294c433075">osRtxEventFlagsCbSize</a> (higher values are permitted).</p>
<p>Default: <span class="XML-Token">0</span> as the default is no memory provided with <a class="el" href="group__CMSIS__RTOS__EventFlags.html#a1e100dc33d403841ed3c344e3397868e">cb_mem</a>. </p>
</td></tr>
</table>
</div>
</div>
<h2 class="groupheader">Typedef Documentation</h2>
<a class="anchor" id="gafdbab933146d6d81d7cca7287e267a50"></a>
<div class="memitem">
<div class="memproto">
<table class="memname">
<tr>
<td class="memname"><a class="el" href="group__CMSIS__RTOS__EventFlags.html#gafdbab933146d6d81d7cca7287e267a50">osEventFlagsId_t</a></td>
</tr>
</table>
</div><div class="memdoc">
<p>Event Flags ID identifies the event flags.</p>
<p>Returned by:</p>
<ul>
<li><a class="el" href="group__CMSIS__RTOS__EventFlags.html#gab14b1caeb12ffa42cce1bfe889cd07df">osEventFlagsNew</a> </li>
</ul>
</div>
</div>
<h2 class="groupheader">Function Documentation</h2>
<a class="anchor" id="gab14b1caeb12ffa42cce1bfe889cd07df"></a>
<div class="memitem">
<div class="memproto">
<table class="memname">
<tr>
<td class="memname"><a class="el" href="group__CMSIS__RTOS__EventFlags.html#gafdbab933146d6d81d7cca7287e267a50">osEventFlagsId_t</a> osEventFlagsNew </td>
<td>(</td>
<td class="paramtype">const <a class="el" href="group__CMSIS__RTOS__EventFlags.html#structosEventFlagsAttr__t">osEventFlagsAttr_t</a> *&#160;</td>
<td class="paramname"><em>attr</em></td><td>)</td>
<td></td>
</tr>
</table>
</div><div class="memdoc">
<dl class="params"><dt>Parameters</dt><dd>
<table class="params">
<tr><td class="paramdir">[in]</td><td class="paramname">attr</td><td>event flags attributes; NULL: default values. </td></tr>
</table>
</dd>
</dl>
<dl class="section return"><dt>Returns</dt><dd>event flags ID for reference by other functions or NULL in case of error.</dd></dl>
<p>The function <b>osEventFlagsNew</b> creates a new event flags object that is used to send events across threads and returns the pointer to the event flags object identifier or <span class="XML-Token">NULL</span> in case of an error. It can be safely called before the RTOS is started (call to <a class="el" href="group__CMSIS__RTOS__KernelCtrl.html#ga9ae2cc00f0d89d7b6a307bba942b5221">osKernelStart</a>), but not before it is initialized (call to <a class="el" href="group__CMSIS__RTOS__KernelCtrl.html#gae818f6611d25ba3140bede410a52d659">osKernelInitialize</a>).</p>
<p>The parameter <em>attr</em> sets the event flags attributes (refer to <a class="el" href="group__CMSIS__RTOS__EventFlags.html#structosEventFlagsAttr__t">osEventFlagsAttr_t</a>). Default attributes will be used if set to <span class="XML-Token">NULL</span>, i.e. kernel memory allocation is used for the event control block.</p>
<dl class="section note"><dt>Note</dt><dd>Cannot be called from <a class="el" href="theory_of_operation.html#CMSIS_RTOS_ISR_Calls">Interrupt Service Routines</a>.</dd></dl>
<p><b>Code Example</b> </p>
<div class="fragment"><div class="line"><span class="preprocessor">#include &quot;<a class="code" href="cmsis__os2_8h.html">cmsis_os2.h</a>&quot;</span> <span class="comment">// CMSIS RTOS header file</span></div>
<div class="line"> </div>
<div class="line"><a class="code" href="group__CMSIS__RTOS__EventFlags.html#gafdbab933146d6d81d7cca7287e267a50">osEventFlagsId_t</a> evt_id; <span class="comment">// message queue id</span></div>
<div class="line"> </div>
<div class="line"><span class="keywordtype">int</span> Init_Events (<span class="keywordtype">void</span>) {</div>
<div class="line"> </div>
<div class="line"> evt_id = <a class="code" href="group__CMSIS__RTOS__EventFlags.html#gab14b1caeb12ffa42cce1bfe889cd07df">osEventFlagsNew</a>(NULL);</div>
<div class="line"> <span class="keywordflow">if</span> (evt_id == NULL) {</div>
<div class="line"> ; <span class="comment">// Event Flags object not created, handle failure</span></div>
<div class="line"> <span class="keywordflow">return</span>(-1);</div>
<div class="line"> }</div>
<div class="line"></div>
<div class="line"> <span class="keywordflow">return</span>(0);</div>
<div class="line">}</div>
</div><!-- fragment -->
</div>
</div>
<a class="anchor" id="ga33b71d14cecf90b4e72639dd19f23a5e"></a>
<div class="memitem">
<div class="memproto">
<table class="memname">
<tr>
<td class="memname">uint32_t osEventFlagsSet </td>
<td>(</td>
<td class="paramtype"><a class="el" href="group__CMSIS__RTOS__EventFlags.html#gafdbab933146d6d81d7cca7287e267a50">osEventFlagsId_t</a>&#160;</td>
<td class="paramname"><em>ef_id</em>, </td>
</tr>
<tr>
<td class="paramkey"></td>
<td></td>
<td class="paramtype">uint32_t&#160;</td>
<td class="paramname"><em>flags</em>&#160;</td>
</tr>
<tr>
<td></td>
<td>)</td>
<td></td><td></td>
</tr>
</table>
</div><div class="memdoc">
<dl class="params"><dt>Parameters</dt><dd>
<table class="params">
<tr><td class="paramdir">[in]</td><td class="paramname">ef_id</td><td>event flags ID obtained by <a class="el" href="group__CMSIS__RTOS__EventFlags.html#gab14b1caeb12ffa42cce1bfe889cd07df">osEventFlagsNew</a>. </td></tr>
<tr><td class="paramdir">[in]</td><td class="paramname">flags</td><td>specifies the flags that shall be set. </td></tr>
</table>
</dd>
</dl>
<dl class="section return"><dt>Returns</dt><dd>event flags after setting or error code if highest bit set.</dd></dl>
<p>The function <b>osEventFlagsSet</b> sets the event flags specified by the parameter <em>flags</em> in an event flags object specified by parameter <em>ef_id</em>. All threads waiting for the flag set will be notified to resume from <a class="el" href="group__CMSIS__RTOS__ThreadMgmt.html#ThreadStates">BLOCKED</a> state. The function returns the event flags after setting or an error code (highest bit is set, refer to <a class="el" href="group__flags__error__codes.html">Flags Functions Error Codes</a>).</p>
<p>Possible <a class="el" href="group__flags__error__codes.html">Flags Functions Error Codes</a> return values:</p>
<ul>
<li><em>osFlagsErrorUnknown:</em> unspecified error.</li>
<li><em>osFlagsErrorParameter:</em> parameter <em>ef_id</em> does not identify a valid event flags object or <em>flags</em> has highest bit set.</li>
<li><em>osFlagsErrorResource:</em> the event flags object is in an invalid state.</li>
</ul>
<dl class="section note"><dt>Note</dt><dd>This function may be called from <a class="el" href="theory_of_operation.html#CMSIS_RTOS_ISR_Calls">Interrupt Service Routines</a>.</dd></dl>
<p><b>Code Example</b> </p>
<div class="fragment"><div class="line"><span class="preprocessor">#include &quot;<a class="code" href="cmsis__os2_8h.html">cmsis_os2.h</a>&quot;</span> <span class="comment">// CMSIS RTOS header file</span></div>
<div class="line"> </div>
<div class="line"><a class="code" href="group__CMSIS__RTOS__EventFlags.html#gafdbab933146d6d81d7cca7287e267a50">osEventFlagsId_t</a> evt_id; <span class="comment">// event flasg id</span></div>
<div class="line"> </div>
<div class="line"><span class="keywordtype">void</span> Thread_EventSender (<span class="keywordtype">void</span> *argument) {</div>
<div class="line"> </div>
<div class="line"> <span class="keywordflow">while</span> (1) { </div>
<div class="line"> <a class="code" href="group__CMSIS__RTOS__EventFlags.html#ga33b71d14cecf90b4e72639dd19f23a5e">osEventFlagsSet</a>(evt_id, 0x00000001U);</div>
<div class="line"> <a class="code" href="group__CMSIS__RTOS__ThreadMgmt.html#gad01c7ec26535b1de6b018bb9466720e2">osThreadYield</a>(); <span class="comment">// suspend thread</span></div>
<div class="line"> }</div>
<div class="line">}</div>
</div><!-- fragment -->
</div>
</div>
<a class="anchor" id="ga93bf258ca0007c6641fbe8e4f2b8a1e5"></a>
<div class="memitem">
<div class="memproto">
<table class="memname">
<tr>
<td class="memname">uint32_t osEventFlagsClear </td>
<td>(</td>
<td class="paramtype"><a class="el" href="group__CMSIS__RTOS__EventFlags.html#gafdbab933146d6d81d7cca7287e267a50">osEventFlagsId_t</a>&#160;</td>
<td class="paramname"><em>ef_id</em>, </td>
</tr>
<tr>
<td class="paramkey"></td>
<td></td>
<td class="paramtype">uint32_t&#160;</td>
<td class="paramname"><em>flags</em>&#160;</td>
</tr>
<tr>
<td></td>
<td>)</td>
<td></td><td></td>
</tr>
</table>
</div><div class="memdoc">
<dl class="params"><dt>Parameters</dt><dd>
<table class="params">
<tr><td class="paramdir">[in]</td><td class="paramname">ef_id</td><td>event flags ID obtained by <a class="el" href="group__CMSIS__RTOS__EventFlags.html#gab14b1caeb12ffa42cce1bfe889cd07df">osEventFlagsNew</a>. </td></tr>
<tr><td class="paramdir">[in]</td><td class="paramname">flags</td><td>specifies the flags that shall be cleared. </td></tr>
</table>
</dd>
</dl>
<dl class="section return"><dt>Returns</dt><dd>event flags before clearing or error code if highest bit set.</dd></dl>
<p>The function <b>osEventFlagsClear</b> clears the event flags specified by the parameter <em>flags</em> in an event flags object specified by parameter <em>ef_id</em>. The function returns the event flags before clearing or an error code (highest bit is set, refer to <a class="el" href="group__flags__error__codes.html">Flags Functions Error Codes</a>).</p>
<p>Possible <a class="el" href="group__flags__error__codes.html">Flags Functions Error Codes</a> return values:</p>
<ul>
<li><em>osFlagsErrorUnknown:</em> unspecified error.</li>
<li><em>osFlagsErrorParameter:</em> parameter <em>ef_id</em> does not identify a valid event flags object or <em>flags</em> has highest bit set.</li>
<li><em>osFlagsErrorResource:</em> the event flags object is in an invalid state.</li>
</ul>
<dl class="section note"><dt>Note</dt><dd>This function may be called from <a class="el" href="theory_of_operation.html#CMSIS_RTOS_ISR_Calls">Interrupt Service Routines</a>. </dd></dl>
</div>
</div>
<a class="anchor" id="ga8bda3185f46bfd278cea8a6cf357677d"></a>
<div class="memitem">
<div class="memproto">
<table class="memname">
<tr>
<td class="memname">uint32_t osEventFlagsGet </td>
<td>(</td>
<td class="paramtype"><a class="el" href="group__CMSIS__RTOS__EventFlags.html#gafdbab933146d6d81d7cca7287e267a50">osEventFlagsId_t</a>&#160;</td>
<td class="paramname"><em>ef_id</em></td><td>)</td>
<td></td>
</tr>
</table>
</div><div class="memdoc">
<dl class="params"><dt>Parameters</dt><dd>
<table class="params">
<tr><td class="paramdir">[in]</td><td class="paramname">ef_id</td><td>event flags ID obtained by <a class="el" href="group__CMSIS__RTOS__EventFlags.html#gab14b1caeb12ffa42cce1bfe889cd07df">osEventFlagsNew</a>. </td></tr>
</table>
</dd>
</dl>
<dl class="section return"><dt>Returns</dt><dd>current event flags.</dd></dl>
<p>The function <b>osEventFlagsGet</b> returns the event flags currently set in an event flags object specified by parameter <em>ef_id</em> or <span class="XML-Token">0</span> in case of an error.</p>
<dl class="section note"><dt>Note</dt><dd>This function may be called from <a class="el" href="theory_of_operation.html#CMSIS_RTOS_ISR_Calls">Interrupt Service Routines</a>. </dd></dl>
</div>
</div>
<a class="anchor" id="ga52acb34a8322e58020227344fe662b4e"></a>
<div class="memitem">
<div class="memproto">
<table class="memname">
<tr>
<td class="memname">uint32_t osEventFlagsWait </td>
<td>(</td>
<td class="paramtype"><a class="el" href="group__CMSIS__RTOS__EventFlags.html#gafdbab933146d6d81d7cca7287e267a50">osEventFlagsId_t</a>&#160;</td>
<td class="paramname"><em>ef_id</em>, </td>
</tr>
<tr>
<td class="paramkey"></td>
<td></td>
<td class="paramtype">uint32_t&#160;</td>
<td class="paramname"><em>flags</em>, </td>
</tr>
<tr>
<td class="paramkey"></td>
<td></td>
<td class="paramtype">uint32_t&#160;</td>
<td class="paramname"><em>options</em>, </td>
</tr>
<tr>
<td class="paramkey"></td>
<td></td>
<td class="paramtype">uint32_t&#160;</td>
<td class="paramname"><em>timeout</em>&#160;</td>
</tr>
<tr>
<td></td>
<td>)</td>
<td></td><td></td>
</tr>
</table>
</div><div class="memdoc">
<dl class="params"><dt>Parameters</dt><dd>
<table class="params">
<tr><td class="paramdir">[in]</td><td class="paramname">ef_id</td><td>event flags ID obtained by <a class="el" href="group__CMSIS__RTOS__EventFlags.html#gab14b1caeb12ffa42cce1bfe889cd07df">osEventFlagsNew</a>. </td></tr>
<tr><td class="paramdir">[in]</td><td class="paramname">flags</td><td>specifies the flags to wait for. </td></tr>
<tr><td class="paramdir">[in]</td><td class="paramname">options</td><td>specifies flags options (osFlagsXxxx). </td></tr>
<tr><td class="paramdir">[in]</td><td class="paramname">timeout</td><td><a class="el" href="theory_of_operation.html#CMSIS_RTOS_TimeOutValue">Timeout Value</a> or 0 in case of no time-out. </td></tr>
</table>
</dd>
</dl>
<dl class="section return"><dt>Returns</dt><dd>event flags before clearing or error code if highest bit set.</dd></dl>
<p>The function <b>osEventFlagsWait</b> suspends the execution of the currently <a class="el" href="group__CMSIS__RTOS__ThreadMgmt.html#ThreadStates">RUNNING</a> thread until any or all event flags specified by the parameter <em>flags</em> in the event object specified by parameter <em>ef_id</em> are set. When these event flags are already set, the function returns instantly. Otherwise, the thread is put into the state <a class="el" href="group__CMSIS__RTOS__ThreadMgmt.html#ThreadStates">BLOCKED</a>.</p>
<p>The <em>options</em> parameter specifies the wait condition: </p>
<table class="doxtable">
<tr>
<th>Option </th><th></th></tr>
<tr>
<td><b>osFlagsWaitAny</b> </td><td>Wait for any flag (default). </td></tr>
<tr>
<td><b>osFlagsWaitAll</b> </td><td>Wait for all flags. </td></tr>
<tr>
<td><b>osFlagsNoClear</b> </td><td>Do not clear flags which have been specified to wait for. </td></tr>
</table>
<p>If <code>osFlagsNoClear</code> is set in the options <a class="el" href="group__CMSIS__RTOS__EventFlags.html#ga93bf258ca0007c6641fbe8e4f2b8a1e5">osEventFlagsClear</a> can be used to clear flags manually.</p>
<p>The parameter <em>timeout</em> specifies how long the system waits for event flags. While the system waits, the thread that is calling this function is put into the <a class="el" href="group__CMSIS__RTOS__ThreadMgmt.html#ThreadStates">BLOCKED</a> state. The parameter <a class="el" href="theory_of_operation.html#CMSIS_RTOS_TimeOutValue">timeout</a> can have the following values:</p>
<ul>
<li>when <em>timeout</em> is <span class="XML-Token">0</span>, the function returns instantly (i.e. try semantics).</li>
<li>when <em>timeout</em> is set to <b>osWaitForever</b> the function will wait for an infinite time until the event flags become available (i.e. wait semantics).</li>
<li>all other values specify a time in kernel ticks for a timeout (i.e. timed-wait semantics).</li>
</ul>
<p>The function returns the event flags before clearing or an error code (highest bit is set, refer to <a class="el" href="group__flags__error__codes.html">Flags Functions Error Codes</a>).</p>
<p>Possible <a class="el" href="group__flags__error__codes.html">Flags Functions Error Codes</a> return values:</p>
<ul>
<li><em>osFlagsErrorUnknown:</em> unspecified error.</li>
<li><em>osFlagsErrorTimeout:</em> awaited flags have not been set in the given time.</li>
<li><em>osFlagsErrorResource:</em> awaited flags have not been set when no <em>timeout</em> was specified.</li>
<li><em>osFlagsErrorParameter:</em> parameter <em>ef_id</em> does not identify a valid event flags object or <em>flags</em> has highest bit set.</li>
</ul>
<dl class="section note"><dt>Note</dt><dd>May be called from <a class="el" href="theory_of_operation.html#CMSIS_RTOS_ISR_Calls">Interrupt Service Routines</a> if the parameter <em>timeout</em> is set to <span class="XML-Token">0</span>.</dd></dl>
<p><b>Code</b> <b>Example</b> </p>
<div class="fragment"><div class="line"><span class="preprocessor">#include &quot;<a class="code" href="cmsis__os2_8h.html">cmsis_os2.h</a>&quot;</span> <span class="comment">// CMSIS RTOS header file</span></div>
<div class="line"> </div>
<div class="line"><a class="code" href="group__CMSIS__RTOS__EventFlags.html#gafdbab933146d6d81d7cca7287e267a50">osEventFlagsId_t</a> evt_id; <span class="comment">// event flasg id</span></div>
<div class="line"> </div>
<div class="line"><span class="keywordtype">void</span> Thread_EventReceiver (<span class="keywordtype">void</span> *argument) {</div>
<div class="line"> uint32_t flags;</div>
<div class="line"> </div>
<div class="line"> <span class="keywordflow">while</span> (1) {</div>
<div class="line"> flags = <a class="code" href="group__CMSIS__RTOS__EventFlags.html#ga52acb34a8322e58020227344fe662b4e">osEventFlagsWait</a>(evt_id, 0x00000001U, <a class="code" href="group__CMSIS__RTOS__Definitions.html#ga18e63587b8450d5b8798b6f6ec04e012">osFlagsWaitAny</a>, <a class="code" href="group__CMSIS__RTOS__Definitions.html#ga9eb9a7a797a42e4b55eb171ecc609ddb">osWaitForever</a>);</div>
<div class="line"> <span class="comment">//handle event</span></div>
<div class="line"> }</div>
<div class="line">}</div>
</div><!-- fragment -->
</div>
</div>
<a class="anchor" id="ga7c4acf2fb0d506ec82905dee53fb5435"></a>
<div class="memitem">
<div class="memproto">
<table class="memname">
<tr>
<td class="memname"><a class="el" href="group__CMSIS__RTOS__Definitions.html#ga6c0dbe6069e4e7f47bb4cd32ae2b813e">osStatus_t</a> osEventFlagsDelete </td>
<td>(</td>
<td class="paramtype"><a class="el" href="group__CMSIS__RTOS__EventFlags.html#gafdbab933146d6d81d7cca7287e267a50">osEventFlagsId_t</a>&#160;</td>
<td class="paramname"><em>ef_id</em></td><td>)</td>
<td></td>
</tr>
</table>
</div><div class="memdoc">
<dl class="params"><dt>Parameters</dt><dd>
<table class="params">
<tr><td class="paramdir">[in]</td><td class="paramname">ef_id</td><td>event flags ID obtained by <a class="el" href="group__CMSIS__RTOS__EventFlags.html#gab14b1caeb12ffa42cce1bfe889cd07df">osEventFlagsNew</a>. </td></tr>
</table>
</dd>
</dl>
<dl class="section return"><dt>Returns</dt><dd>status code that indicates the execution status of the function.</dd></dl>
<p>The function <b>osEventFlagsDelete</b> deletes the event flags object specified by parameter <em>ef_id</em> and releases the internal memory obtained for the event flags handling. After this call, the <em>ef_id</em> is no longer valid and cannot be used. This can cause starvation of threads that are waiting for flags of this event object. The <em>ef_id</em> may be created again using the function <a class="el" href="group__CMSIS__RTOS__EventFlags.html#gab14b1caeb12ffa42cce1bfe889cd07df">osEventFlagsNew</a>.</p>
<p>Possible <a class="el" href="group__CMSIS__RTOS__Definitions.html#ga6c0dbe6069e4e7f47bb4cd32ae2b813e">osStatus_t</a> return values:</p>
<ul>
<li><em>osOK:</em> the specified event flags object has been deleted.</li>
<li><em>osErrorISR:</em> <b>osEventFlagsDelete</b> cannot be called from interrupt service routines.</li>
<li><em>osErrorParameter:</em> parameter <em>ef_id</em> is <span class="XML-Token">NULL</span> or invalid.</li>
<li><em>osErrorResource:</em> the event flags object is in an invalid state.</li>
</ul>
<dl class="section note"><dt>Note</dt><dd>This function <b>cannot</b> be called from <a class="el" href="theory_of_operation.html#CMSIS_RTOS_ISR_Calls">Interrupt Service Routines</a>. </dd></dl>
</div>
</div>
<a class="anchor" id="ga59f4ddf0ee8c395b1672bb978d1cfc88"></a>
<div class="memitem">
<div class="memproto">
<table class="memname">
<tr>
<td class="memname">const char * osEventFlagsGetName </td>
<td>(</td>
<td class="paramtype"><a class="el" href="group__CMSIS__RTOS__EventFlags.html#gafdbab933146d6d81d7cca7287e267a50">osEventFlagsId_t</a>&#160;</td>
<td class="paramname"><em>ef_id</em></td><td>)</td>
<td></td>
</tr>
</table>
</div><div class="memdoc">
<dl class="params"><dt>Parameters</dt><dd>
<table class="params">
<tr><td class="paramdir">[in]</td><td class="paramname">ef_id</td><td>event flags ID obtained by <a class="el" href="group__CMSIS__RTOS__EventFlags.html#gab14b1caeb12ffa42cce1bfe889cd07df">osEventFlagsNew</a>. </td></tr>
</table>
</dd>
</dl>
<dl class="section return"><dt>Returns</dt><dd>name as null-terminated string.</dd></dl>
<p>The function <b>osEventFlagsGetName</b> returns the pointer to the name string of the event flags object identified by parameter <em>ef_id</em> or <span class="XML-Token">NULL</span> in case of an error.</p>
<dl class="section note"><dt>Note</dt><dd>This function <b>cannot</b> be called from <a class="el" href="theory_of_operation.html#CMSIS_RTOS_ISR_Calls">Interrupt Service Routines</a>.</dd></dl>
<p><b>Code Example</b> </p>
<div class="fragment"><div class="line"><span class="preprocessor">#include &quot;<a class="code" href="cmsis__os2_8h.html">cmsis_os2.h</a>&quot;</span> <span class="comment">// CMSIS RTOS header file</span></div>
<div class="line"> </div>
<div class="line"><a class="code" href="group__CMSIS__RTOS__EventFlags.html#gafdbab933146d6d81d7cca7287e267a50">osEventFlagsId_t</a> evt_id; <span class="comment">// event flasg id</span></div>
<div class="line"> </div>
<div class="line"><span class="keywordtype">void</span> EvtFlagsGetName_example (<span class="keywordtype">void</span>) {</div>
<div class="line"> <span class="keywordtype">char</span> *name;</div>
<div class="line"> </div>
<div class="line"> name = <a class="code" href="group__CMSIS__RTOS__EventFlags.html#ga59f4ddf0ee8c395b1672bb978d1cfc88">osEventFlagsGetName</a>(evt_id);</div>
<div class="line"> <span class="keywordflow">if</span> (name == NULL) {</div>
<div class="line"> <span class="comment">// Failed to get the event flags object name</span></div>
<div class="line"> }</div>
<div class="line">}</div>
</div><!-- fragment -->
</div>
</div>
</div><!-- contents -->
</div><!-- doc-content -->
<!-- start footer part -->
<div id="nav-path" class="navpath"><!-- id is needed for treeview function! -->
<ul>
<li class="footer">Generated on Wed Jul 10 2019 15:21:04 for CMSIS-RTOS2 Version 2.1.3 by Arm Ltd. All rights reserved.
<!--
<a href="http://www.doxygen.org/index.html">
<img class="footer" src="doxygen.png" alt="doxygen"/></a> 1.8.6
-->
</li>
</ul>
</div>
</body>
</html>