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Breadcrumbs go here --> <li><a href="modules.html">Modules</a></li> <li><a href="qtcore.html">QtCore</a></li> <li>QWriteLocker</li> </ul> </div> <div class="toolbuttons toolblock"> <ul> <li id="smallA" class="t_button">A</li> <li id="medA" class="t_button active">A</li> <li id="bigA" class="t_button">A</li> <li id="print" class="t_button"><a href="javascript:this.print();"> <span>Print</span></a></li> </ul> </div> </div> <div class="content mainContent"> <div class="toc"> <h3><a name="toc">Contents</a></h3> <ul> <li class="level1"><a href="#public-functions">Public Functions</a></li> <li class="level1"><a href="#details">Detailed Description</a></li> </ul> </div> <h1 class="title">QWriteLocker Class Reference</h1> <!-- $$$QWriteLocker-brief --> <p>The QWriteLocker class is a convenience class that simplifies locking and unlocking read-write locks for write access. <a href="#details">More...</a></p> <!-- @@@QWriteLocker --> <pre class="cpp"> <span class="preprocessor">#include <QWriteLocker></span></pre><p><b>Note:</b> All functions in this class are <a href="threads-reentrancy.html#thread-safe">thread-safe</a>.</p> <ul> <li><a href="qwritelocker-members.html">List of all members, including inherited members</a></li> </ul> <a name="public-functions"></a> <h2>Public Functions</h2> <table class="alignedsummary"> <tr><td class="memItemLeft rightAlign topAlign"> </td><td class="memItemRight bottomAlign"><b><a href="qwritelocker.html#QWriteLocker">QWriteLocker</a></b> ( QReadWriteLock * <i>lock</i> )</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> </td><td class="memItemRight bottomAlign"><b><a href="qwritelocker.html#dtor.QWriteLocker">~QWriteLocker</a></b> ()</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> QReadWriteLock * </td><td class="memItemRight bottomAlign"><b><a href="qwritelocker.html#readWriteLock">readWriteLock</a></b> () const</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> void </td><td class="memItemRight bottomAlign"><b><a href="qwritelocker.html#relock">relock</a></b> ()</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> void </td><td class="memItemRight bottomAlign"><b><a href="qwritelocker.html#unlock">unlock</a></b> ()</td></tr> </table> <a name="details"></a> <!-- $$$QWriteLocker-description --> <div class="descr"> <h2>Detailed Description</h2> <p>The QWriteLocker class is a convenience class that simplifies locking and unlocking read-write locks for write access.</p> <p>The purpose of QWriteLocker (and <a href="qreadlocker.html">QReadLocker</a> is to simplify <a href="qreadwritelock.html">QReadWriteLock</a> locking and unlocking. Locking and unlocking statements or in exception handling code is error-prone and difficult to debug. QWriteLocker can be used in such situations to ensure that the state of the lock is always well-defined.</p> <p>Here's an example that uses QWriteLocker to lock and unlock a read-write lock for writing:</p> <pre class="cpp"> <span class="type"><a href="qreadwritelock.html">QReadWriteLock</a></span> lock; <span class="type">void</span> writeData(<span class="keyword">const</span> <span class="type"><a href="qbytearray.html">QByteArray</a></span> <span class="operator">&</span>data) { <span class="type">QWriteLocker</span> locker(<span class="operator">&</span>lock); <span class="operator">.</span><span class="operator">.</span><span class="operator">.</span> }</pre> <p>It is equivalent to the following code:</p> <pre class="cpp"> <span class="type"><a href="qreadwritelock.html">QReadWriteLock</a></span> lock; <span class="type">void</span> writeData(<span class="keyword">const</span> <span class="type"><a href="qbytearray.html">QByteArray</a></span> <span class="operator">&</span>data) { lock<span class="operator">.</span>lockForWrite(); <span class="operator">.</span><span class="operator">.</span><span class="operator">.</span> lock<span class="operator">.</span>unlock(); }</pre> <p>The <a href="qmutexlocker.html">QMutexLocker</a> documentation shows examples where the use of a locker object greatly simplifies programming.</p> </div> <p><b>See also </b><a href="qreadlocker.html">QReadLocker</a> and <a href="qreadwritelock.html">QReadWriteLock</a>.</p> <!-- @@@QWriteLocker --> <div class="func"> <h2>Member Function Documentation</h2> <!-- $$$QWriteLocker[overload1]$$$QWriteLockerQReadWriteLock* --> <h3 class="fn"><a name="QWriteLocker"></a>QWriteLocker::<span class="name">QWriteLocker</span> ( <span class="type"><a href="qreadwritelock.html">QReadWriteLock</a></span> * <i>lock</i> )</h3> <p>Constructs a <a href="qwritelocker.html">QWriteLocker</a> and locks <i>lock</i> for writing. The lock will be unlocked when the <a href="qwritelocker.html">QWriteLocker</a> is destroyed. If <tt>lock</tt> is zero, <a href="qwritelocker.html">QWriteLocker</a> does nothing.</p> <p><b>See also </b><a href="qreadwritelock.html#lockForWrite">QReadWriteLock::lockForWrite</a>().</p> <!-- @@@QWriteLocker --> <!-- $$$~QWriteLocker[overload1]$$$~QWriteLocker --> <h3 class="fn"><a name="dtor.QWriteLocker"></a>QWriteLocker::<span class="name">~QWriteLocker</span> ()</h3> <p>Destroys the <a href="qwritelocker.html">QWriteLocker</a> and unlocks the lock that was passed to the constructor.</p> <p><b>See also </b><a href="qreadwritelock.html#unlock">QReadWriteLock::unlock</a>().</p> <!-- @@@~QWriteLocker --> <!-- $$$readWriteLock[overload1]$$$readWriteLock --> <h3 class="fn"><a name="readWriteLock"></a><span class="type"><a href="qreadwritelock.html">QReadWriteLock</a></span> * QWriteLocker::<span class="name">readWriteLock</span> () const</h3> <p>Returns a pointer to the read-write lock that was passed to the constructor.</p> <!-- @@@readWriteLock --> <!-- $$$relock[overload1]$$$relock --> <h3 class="fn"><a name="relock"></a><span class="type">void</span> QWriteLocker::<span class="name">relock</span> ()</h3> <p>Relocks an unlocked lock.</p> <p><b>See also </b><a href="qwritelocker.html#unlock">unlock</a>().</p> <!-- @@@relock --> <!-- $$$unlock[overload1]$$$unlock --> <h3 class="fn"><a name="unlock"></a><span class="type">void</span> QWriteLocker::<span class="name">unlock</span> ()</h3> <p>Unlocks the lock associated with this locker.</p> <p><b>See also </b><a href="qreadwritelock.html#unlock">QReadWriteLock::unlock</a>().</p> <!-- @@@unlock --> </div> </div> </div> </div> <div class="ft"> <span></span> </div> </div> <div class="footer"> <p> <acronym title="Copyright">©</acronym> 2015 The Qt Company Ltd. 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