<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE html> <html lang="en"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <!-- qfuturesynchronizer.qdoc --> <title>QFutureSynchronizer Class | Qt Core 5.9</title> <link rel="stylesheet" type="text/css" href="style/offline-simple.css" /> <script type="text/javascript"> document.getElementsByTagName("link").item(0).setAttribute("href", "style/offline.css"); // loading style sheet breaks anchors that were jumped to before // so force jumping to anchor again setTimeout(function() { var anchor = location.hash; // need to jump to different anchor first (e.g. none) location.hash = "#"; setTimeout(function() { location.hash = anchor; }, 0); }, 0); </script> </head> <body> <div class="header" id="qtdocheader"> <div class="main"> <div class="main-rounded"> <div class="navigationbar"> <table><tr> <td >Qt 5.9</td><td ><a href="qtcore-index.html">Qt Core</a></td><td ><a href="qtcore-module.html">C++ Classes</a></td><td >QFutureSynchronizer</td></tr></table><table class="buildversion"><tr> <td id="buildversion" width="100%" align="right">Qt 5.9.4 Reference Documentation</td> </tr></table> </div> </div> <div class="content"> <div class="line"> <div class="content mainContent"> <div class="sidebar"> <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> <div class="sidebar-content" id="sidebar-content"></div></div> <h1 class="title">QFutureSynchronizer Class</h1> <!-- $$$QFutureSynchronizer-brief --> <p>The <a href="qfuturesynchronizer.html">QFutureSynchronizer</a> class is a convenience class that simplifies <a href="qfuture.html">QFuture</a> synchronization. <a href="#details">More...</a></p> <!-- @@@QFutureSynchronizer --> <div class="table"><table class="alignedsummary"> <tr><td class="memItemLeft rightAlign topAlign"> Header:</td><td class="memItemRight bottomAlign"> <span class="preprocessor">#include <QFutureSynchronizer></span> </td></tr><tr><td class="memItemLeft rightAlign topAlign"> qmake:</td><td class="memItemRight bottomAlign"> QT += core</td></tr><tr><td class="memItemLeft rightAlign topAlign"> Since:</td><td class="memItemRight bottomAlign"> Qt 4.4</td></tr></table></div><ul> <li><a href="qfuturesynchronizer-members.html">List of all members, including inherited members</a></li> </ul> <a name="public-functions"></a> <h2 id="public-functions">Public Functions</h2> <div class="table"><table class="alignedsummary"> <tr><td class="memItemLeft rightAlign topAlign"> </td><td class="memItemRight bottomAlign"><b><a href="qfuturesynchronizer.html#QFutureSynchronizer">QFutureSynchronizer</a></b>()</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> </td><td class="memItemRight bottomAlign"><b><a href="qfuturesynchronizer.html#QFutureSynchronizer-1">QFutureSynchronizer</a></b>(const QFuture<T> &<i>future</i>)</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> </td><td class="memItemRight bottomAlign"><b><a href="qfuturesynchronizer.html#dtor.QFutureSynchronizer">~QFutureSynchronizer</a></b>()</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> void </td><td class="memItemRight bottomAlign"><b><a href="qfuturesynchronizer.html#addFuture">addFuture</a></b>(const QFuture<T> &<i>future</i>)</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> bool </td><td class="memItemRight bottomAlign"><b><a href="qfuturesynchronizer.html#cancelOnWait">cancelOnWait</a></b>() const</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> void </td><td class="memItemRight bottomAlign"><b><a href="qfuturesynchronizer.html#clearFutures">clearFutures</a></b>()</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> QList<QFuture<T> > </td><td class="memItemRight bottomAlign"><b><a href="qfuturesynchronizer.html#futures">futures</a></b>() const</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> void </td><td class="memItemRight bottomAlign"><b><a href="qfuturesynchronizer.html#setCancelOnWait">setCancelOnWait</a></b>(bool <i>enabled</i>)</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> void </td><td class="memItemRight bottomAlign"><b><a href="qfuturesynchronizer.html#setFuture">setFuture</a></b>(const QFuture<T> &<i>future</i>)</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> void </td><td class="memItemRight bottomAlign"><b><a href="qfuturesynchronizer.html#waitForFinished">waitForFinished</a></b>()</td></tr> </table></div> <a name="details"></a> <!-- $$$QFutureSynchronizer-description --> <div class="descr"> <h2 id="details">Detailed Description</h2> <p>The <a href="qfuturesynchronizer.html">QFutureSynchronizer</a> class is a convenience class that simplifies <a href="qfuture.html">QFuture</a> synchronization.</p> <p><a href="qfuturesynchronizer.html">QFutureSynchronizer</a> is a template class that simplifies synchronization of one or more <a href="qfuture.html">QFuture</a> objects. Futures are added using the <a href="qfuturesynchronizer.html#addFuture">addFuture</a>() or <a href="qfuturesynchronizer.html#setFuture">setFuture</a>() functions. The <a href="qfuturesynchronizer.html#futures">futures</a>() function returns a list of futures. Use <a href="qfuturesynchronizer.html#clearFutures">clearFutures</a>() to remove all futures from the <a href="qfuturesynchronizer.html">QFutureSynchronizer</a>.</p> <p>The <a href="qfuturesynchronizer.html#waitForFinished">waitForFinished</a>() function waits for all futures to finish. The destructor of <a href="qfuturesynchronizer.html">QFutureSynchronizer</a> calls <a href="qfuturesynchronizer.html#waitForFinished">waitForFinished</a>(), providing an easy way to ensure that all futures have finished before returning from a function:</p> <pre class="cpp"> <span class="type">void</span> someFunction() { <span class="type"><a href="qfuturesynchronizer.html#QFutureSynchronizer">QFutureSynchronizer</a></span><span class="operator"><</span><span class="type">void</span><span class="operator">></span> synchronizer; <span class="operator">.</span><span class="operator">.</span><span class="operator">.</span> synchronizer<span class="operator">.</span>addFuture(<span class="type"><a href="../qtconcurrent/qtconcurrent.html">QtConcurrent</a></span><span class="operator">::</span>run(anotherFunction)); synchronizer<span class="operator">.</span>addFuture(<span class="type"><a href="../qtconcurrent/qtconcurrent.html">QtConcurrent</a></span><span class="operator">::</span>map(list<span class="operator">,</span> mapFunction)); <span class="keyword">return</span>; <span class="comment">// QFutureSynchronizer waits for all futures to finish</span> } </pre> <p>The behavior of <a href="qfuturesynchronizer.html#waitForFinished">waitForFinished</a>() can be changed using the <a href="qfuturesynchronizer.html#setCancelOnWait">setCancelOnWait</a>() function. Calling <a href="qfuturesynchronizer.html#setCancelOnWait">setCancelOnWait</a>(true) will cause <a href="qfuturesynchronizer.html#waitForFinished">waitForFinished</a>() to cancel all futures before waiting for them to finish. You can query the status of the cancel-on-wait feature using the <a href="qfuturesynchronizer.html#cancelOnWait">cancelOnWait</a>() function.</p> </div> <p><b>See also </b><a href="qfuture.html">QFuture</a>, <a href="qfuturewatcher.html">QFutureWatcher</a>, and <a href="../qtconcurrent/qtconcurrent-index.html">Qt Concurrent</a>.</p> <!-- @@@QFutureSynchronizer --> <div class="func"> <h2>Member Function Documentation</h2> <!-- $$$QFutureSynchronizer[overload1]$$$QFutureSynchronizer --> <h3 class="fn" id="QFutureSynchronizer"><a name="QFutureSynchronizer"></a>QFutureSynchronizer::<span class="name">QFutureSynchronizer</span>()</h3> <p>Constructs a <a href="qfuturesynchronizer.html">QFutureSynchronizer</a>.</p> <!-- @@@QFutureSynchronizer --> <!-- $$$QFutureSynchronizer$$$QFutureSynchronizerconstQFuture<T>& --> <h3 class="fn" id="QFutureSynchronizer-1"><a name="QFutureSynchronizer-1"></a>QFutureSynchronizer::<span class="name">QFutureSynchronizer</span>(const <span class="type"><a href="qfuture.html">QFuture</a></span><<span class="type">T</span>> &<i>future</i>)</h3> <p>Constructs a <a href="qfuturesynchronizer.html">QFutureSynchronizer</a> and begins watching <i>future</i> by calling <a href="qfuturesynchronizer.html#addFuture">addFuture</a>().</p> <p><b>See also </b><a href="qfuturesynchronizer.html#addFuture">addFuture</a>().</p> <!-- @@@QFutureSynchronizer --> <!-- $$$~QFutureSynchronizer[overload1]$$$~QFutureSynchronizer --> <h3 class="fn" id="dtor.QFutureSynchronizer"><a name="dtor.QFutureSynchronizer"></a>QFutureSynchronizer::<span class="name">~QFutureSynchronizer</span>()</h3> <p>Calls <a href="qfuturesynchronizer.html#waitForFinished">waitForFinished</a>() function to ensure that all futures have finished before destroying this <a href="qfuturesynchronizer.html">QFutureSynchronizer</a>.</p> <p><b>See also </b><a href="qfuturesynchronizer.html#waitForFinished">waitForFinished</a>().</p> <!-- @@@~QFutureSynchronizer --> <!-- $$$addFuture[overload1]$$$addFutureconstQFuture<T>& --> <h3 class="fn" id="addFuture"><a name="addFuture"></a><span class="type">void</span> QFutureSynchronizer::<span class="name">addFuture</span>(const <span class="type"><a href="qfuture.html">QFuture</a></span><<span class="type">T</span>> &<i>future</i>)</h3> <p>Adds <i>future</i> to the list of managed futures.</p> <p><b>See also </b><a href="qfuturesynchronizer.html#futures">futures</a>().</p> <!-- @@@addFuture --> <!-- $$$cancelOnWait[overload1]$$$cancelOnWait --> <h3 class="fn" id="cancelOnWait"><a name="cancelOnWait"></a><span class="type">bool</span> QFutureSynchronizer::<span class="name">cancelOnWait</span>() const</h3> <p>Returns <code>true</code> if the cancel-on-wait feature is enabled; otherwise returns false. If cancel-on-wait is enabled, the <a href="qfuturesynchronizer.html#waitForFinished">waitForFinished</a>() function will cancel all futures before waiting for them to finish.</p> <p><b>See also </b><a href="qfuturesynchronizer.html#setCancelOnWait">setCancelOnWait</a>() and <a href="qfuturesynchronizer.html#waitForFinished">waitForFinished</a>().</p> <!-- @@@cancelOnWait --> <!-- $$$clearFutures[overload1]$$$clearFutures --> <h3 class="fn" id="clearFutures"><a name="clearFutures"></a><span class="type">void</span> QFutureSynchronizer::<span class="name">clearFutures</span>()</h3> <p>Removes all managed futures from this <a href="qfuturesynchronizer.html">QFutureSynchronizer</a>.</p> <p><b>See also </b><a href="qfuturesynchronizer.html#addFuture">addFuture</a>() and <a href="qfuturesynchronizer.html#setFuture">setFuture</a>().</p> <!-- @@@clearFutures --> <!-- $$$futures[overload1]$$$futures --> <h3 class="fn" id="futures"><a name="futures"></a><span class="type"><a href="qlist.html">QList</a></span><<span class="type"><a href="qfuture.html">QFuture</a></span><<span class="type">T</span>> > QFutureSynchronizer::<span class="name">futures</span>() const</h3> <p>Returns a list of all managed futures.</p> <p><b>See also </b><a href="qfuturesynchronizer.html#addFuture">addFuture</a>() and <a href="qfuturesynchronizer.html#setFuture">setFuture</a>().</p> <!-- @@@futures --> <!-- $$$setCancelOnWait[overload1]$$$setCancelOnWaitbool --> <h3 class="fn" id="setCancelOnWait"><a name="setCancelOnWait"></a><span class="type">void</span> QFutureSynchronizer::<span class="name">setCancelOnWait</span>(<span class="type">bool</span> <i>enabled</i>)</h3> <p>Enables or disables the cancel-on-wait feature based on the <i>enabled</i> argument. If <i>enabled</i> is true, the <a href="qfuturesynchronizer.html#waitForFinished">waitForFinished</a>() function will cancel all futures before waiting for them to finish.</p> <p><b>See also </b><a href="qfuturesynchronizer.html#cancelOnWait">cancelOnWait</a>() and <a href="qfuturesynchronizer.html#waitForFinished">waitForFinished</a>().</p> <!-- @@@setCancelOnWait --> <!-- $$$setFuture[overload1]$$$setFutureconstQFuture<T>& --> <h3 class="fn" id="setFuture"><a name="setFuture"></a><span class="type">void</span> QFutureSynchronizer::<span class="name">setFuture</span>(const <span class="type"><a href="qfuture.html">QFuture</a></span><<span class="type">T</span>> &<i>future</i>)</h3> <p>Sets <i>future</i> to be the only future managed by this <a href="qfuturesynchronizer.html">QFutureSynchronizer</a>. This is a convenience function that calls <a href="qfuturesynchronizer.html#waitForFinished">waitForFinished</a>(), then <a href="qfuturesynchronizer.html#clearFutures">clearFutures</a>(), and finally passes <i>future</i> to <a href="qfuturesynchronizer.html#addFuture">addFuture</a>().</p> <p><b>See also </b><a href="qfuturesynchronizer.html#addFuture">addFuture</a>(), <a href="qfuturesynchronizer.html#waitForFinished">waitForFinished</a>(), and <a href="qfuturesynchronizer.html#clearFutures">clearFutures</a>().</p> <!-- @@@setFuture --> <!-- $$$waitForFinished[overload1]$$$waitForFinished --> <h3 class="fn" id="waitForFinished"><a name="waitForFinished"></a><span class="type">void</span> QFutureSynchronizer::<span class="name">waitForFinished</span>()</h3> <p>Waits for all futures to finish. If <a href="qfuturesynchronizer.html#cancelOnWait">cancelOnWait</a>() returns <code>true</code>, each future is canceled before waiting for them to finish.</p> <p><b>See also </b><a href="qfuturesynchronizer.html#cancelOnWait">cancelOnWait</a>() and <a href="qfuturesynchronizer.html#setCancelOnWait">setCancelOnWait</a>().</p> <!-- @@@waitForFinished --> </div> </div> </div> </div> </div> </div> <div class="footer"> <p> <acronym title="Copyright">©</acronym> 2017 The Qt Company Ltd. Documentation contributions included herein are the copyrights of their respective owners.<br> The documentation provided herein is licensed under the terms of the <a href="http://www.gnu.org/licenses/fdl.html">GNU Free Documentation License version 1.3</a> as published by the Free Software Foundation.<br> Qt and respective logos are trademarks of The Qt Company Ltd. in Finland and/or other countries worldwide. All other trademarks are property of their respective owners. </p> </div> </body> </html>