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<h1 class="title">QFutureSynchronizer Class Reference</h1>
<!-- $$$QFutureSynchronizer-brief -->
<p>The QFutureSynchronizer class is a convenience class that simplifies <a href="qfuture.html">QFuture</a> synchronization. <a href="#details">More...</a></p>
<!-- @@@QFutureSynchronizer -->
<pre class="cpp"> <span class="preprocessor">#include &lt;QFutureSynchronizer&gt;</span></pre><p>This class was introduced in Qt 4.4.</p>
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<li><a href="qfuturesynchronizer-members.html">List of all members, including inherited members</a></li>
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<h2>Public Functions</h2>
<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-2">QFutureSynchronizer</a></b> ( const QFuture&lt;T&gt; &amp; <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&lt;T&gt; &amp; <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&lt;QFuture&lt;T&gt; &gt; </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&lt;T&gt; &amp; <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>
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<a name="details"></a>
<!-- $$$QFutureSynchronizer-description -->
<div class="descr">
<h2>Detailed Description</h2>
<p>The QFutureSynchronizer class is a convenience class that simplifies <a href="qfuture.html">QFuture</a> synchronization.</p>
<p>QFutureSynchronizer 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 QFutureSynchronizer.</p>
<p>The <a href="qfuturesynchronizer.html#waitForFinished">waitForFinished</a>() function waits for all futures to finish. The destructor of QFutureSynchronizer 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">QFutureSynchronizer</span><span class="operator">&lt;</span><span class="type">void</span><span class="operator">&gt;</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.html">QtConcurrent</a></span><span class="operator">::</span>run(anotherFunction));
synchronizer<span class="operator">.</span>addFuture(<span class="type"><a href="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 setCancelOnWait(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>
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<p><b>See also </b><a href="qfuture.html">QFuture</a>, <a href="qfuturewatcher.html">QFutureWatcher</a>, and <a href="threads-qtconcurrent.html">Qt Concurrent</a>.</p>
<!-- @@@QFutureSynchronizer -->
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<h2>Member Function Documentation</h2>
<!-- $$$QFutureSynchronizer[overload1]$$$QFutureSynchronizer -->
<h3 class="fn"><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"><a name="QFutureSynchronizer-2"></a>QFutureSynchronizer::<span class="name">QFutureSynchronizer</span> ( const <span class="type"><a href="qfuture.html">QFuture</a></span>&lt;<span class="type">T</span>&gt; &amp; <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"><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"><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>&lt;<span class="type">T</span>&gt; &amp; <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"><a name="cancelOnWait"></a><span class="type">bool</span> QFutureSynchronizer::<span class="name">cancelOnWait</span> () const</h3>
<p>Returns true 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"><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"><a name="futures"></a><span class="type"><a href="qlist.html">QList</a></span>&lt;<span class="type"><a href="qfuture.html">QFuture</a></span>&lt;<span class="type">T</span>&gt; &gt; 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"><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"><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>&lt;<span class="type">T</span>&gt; &amp; <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"><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 true, 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 -->
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