diff -r 000000000000 -r 1918ee327afb src/corelib/concurrent/qtconcurrentmedian.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/corelib/concurrent/qtconcurrentmedian.h	Mon Jan 11 14:00:40 2010 +0000
@@ -0,0 +1,130 @@
+/****************************************************************************
+**
+** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the QtCore module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the Technology Preview License Agreement accompanying
+** this package.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain additional
+** rights.  These rights are described in the Nokia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@nokia.com.
+**
+**
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QTCONCURRENT_MEDIAN_H
+#define QTCONCURRENT_MEDIAN_H
+
+#include <QtCore/qglobal.h>
+
+#ifndef QT_NO_CONCURRENT
+
+#include <QtCore/qvector.h>
+#include <QtCore/qalgorithms.h>
+
+QT_BEGIN_HEADER
+QT_BEGIN_NAMESPACE
+
+QT_MODULE(Core)
+
+#ifndef qdoc
+
+namespace QtConcurrent {
+
+template <typename T>
+class Median
+{
+public:
+    Median(int _bufferSize)
+        : currentMedian(), bufferSize(_bufferSize), currentIndex(0), valid(false), dirty(true)
+    {
+        values.resize(bufferSize);
+    }
+
+    void reset()
+    {
+        values.fill(0);
+        currentIndex = 0;
+        valid = false;
+        dirty = true;
+    }
+
+    void addValue(T value)
+    {
+        currentIndex = ((currentIndex + 1) % bufferSize);
+        if (valid == false && currentIndex % bufferSize == 0)
+            valid = true;
+
+        // Only update the cached median value when we have to, that
+        // is when the new value is on then other side of the median
+        // compared to the current value at the index.
+        const T currentIndexValue = values[currentIndex];
+        if ((currentIndexValue > currentMedian && currentMedian > value)
+            || (currentMedian > currentIndexValue && value > currentMedian)) {
+            dirty = true;
+        }
+
+        values[currentIndex] = value;
+    }
+
+    bool isMedianValid() const
+    {
+        return valid;
+    }
+
+    T median()
+    {
+        if (dirty) {
+            dirty = false;
+            QVector<T> sorted = values;
+            qSort(sorted);
+            currentMedian = sorted.at(bufferSize / 2 + 1);
+        }
+        return currentMedian;
+    }
+private:
+    QVector<T> values;
+    T currentMedian;
+    int bufferSize;
+    int currentIndex;
+    bool valid;
+    bool dirty;
+};
+
+} // namespace QtConcurrent
+
+#endif //qdoc
+
+QT_END_NAMESPACE
+QT_END_HEADER
+
+#endif // QT_NO_CONCURRENT
+
+#endif