<?xml version="1.0" encoding="iso-8859-1"?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "DTD/xhtml1-strict.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> <!-- /tmp/qt-4.3.4-qt-1203442408707/qt-x11-opensource-src-4.3.4/src/corelib/thread/qmutex.cpp --> <head> <title>Qt 4.3: Qt 3 Support Members for QMutex</title> <link href="classic.css" rel="stylesheet" type="text/css" /> </head> <body> <table border="0" cellpadding="0" cellspacing="0" width="100%"> <tr> <td align="left" valign="top" width="32"><a href="http://www.trolltech.com/products/qt"><img src="images/qt-logo.png" align="left" width="32" height="32" border="0" /></a></td> <td width="1"> </td><td class="postheader" valign="center"><a href="index.html"><font color="#004faf">Home</font></a> · <a href="classes.html"><font color="#004faf">All Classes</font></a> · <a href="mainclasses.html"><font color="#004faf">Main Classes</font></a> · <a href="groups.html"><font color="#004faf">Grouped Classes</font></a> · <a href="modules.html"><font color="#004faf">Modules</font></a> · <a href="functions.html"><font color="#004faf">Functions</font></a></td> <td align="right" valign="top" width="230"><a href="http://www.trolltech.com"><img src="images/trolltech-logo.png" align="right" width="203" height="32" border="0" /></a></td></tr></table><h1 align="center">Qt 3 Support Members for QMutex</h1> <p><b>The following class members are part of the <a href="qt3support.html">Qt 3 support layer</a>.</b> They are provided to help you port old code to Qt 4. We advise against using them in new code.</p> <p><ul><li><a href="qmutex.html">QMutex class reference</a></li></ul></p> <h3>Public Functions</h3> <ul> <li><div class="fn"/><b><a href="qmutex-qt3.html#QMutex-2">QMutex</a></b> ( bool <i>recursive</i> )</li> <li><div class="fn"/>bool <b><a href="qmutex-qt3.html#locked">locked</a></b> ()</li> </ul> <hr /> <h2>Member Function Documentation</h2> <h3 class="fn"><a name="QMutex-2"></a>QMutex::QMutex ( bool <i>recursive</i> )</h3> <p>Use the constructor that takes a <a href="qmutex.html#RecursionMode-enum">RecursionMode</a> parameter instead.</p> <h3 class="fn"><a name="locked"></a>bool QMutex::locked ()</h3> <p>Returns true if the mutex is locked by another thread; otherwise returns false.</p> <p>It is generally a bad idea to use this function, because code that uses it has a race condition. Use <a href="qmutex.html#tryLock">tryLock</a>() and <a href="qmutex.html#unlock">unlock</a>() instead.</p> <p>For example, if you have code like</p> <pre><font color="#404040"> bool isLocked = mutex.locked();</font></pre> <p>you can rewrite it as</p> <pre> bool isLocked = true; if (mutex.tryLock()) { mutex.unlock(); isLocked = false; }</pre> <p /><address><hr /><div align="center"> <table width="100%" cellspacing="0" border="0"><tr class="address"> <td width="30%">Copyright © 2008 <a href="trolltech.html">Trolltech</a></td> <td width="40%" align="center"><a href="trademarks.html">Trademarks</a></td> <td width="30%" align="right"><div align="right">Qt 4.3.4</div></td> </tr></table></div></address></body> </html>