1 files changed, 183 insertions, 0 deletions
diff --git a/src/corelib/tools/qelapsedtimer_win.cpp b/src/corelib/tools/qelapsedtimer_win.cpp
new file mode 100644
index 0000000000..b3210f18a2
--- /dev/null
+++ b/src/corelib/tools/qelapsedtimer_win.cpp
@@ -0,0 +1,183 @@
+/****************************************************************************
+**
+** Copyright (C) 2011 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.
+**
+**
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qelapsedtimer.h"
+#include <windows.h>
+
+// Result of QueryPerformanceFrequency, 0 indicates that the high resolution timer is unavailable
+static quint64 counterFrequency = 0;
+
+typedef ULONGLONG (WINAPI *PtrGetTickCount64)(void);
+static PtrGetTickCount64 ptrGetTickCount64 = 0;
+
+QT_BEGIN_NAMESPACE
+
+static void resolveLibs()
+{
+    static bool done = false;
+    if (done)
+        return;
+
+    // try to get GetTickCount64 from the system
+    HMODULE kernel32 = GetModuleHandleW(L"kernel32");
+    if (!kernel32)
+        return;
+
+#if defined(Q_OS_WINCE)
+    // does this function exist on WinCE, or will ever exist?
+    ptrGetTickCount64 = (PtrGetTickCount64)GetProcAddress(kernel32, L"GetTickCount64");
+#else
+    ptrGetTickCount64 = (PtrGetTickCount64)GetProcAddress(kernel32, "GetTickCount64");
+#endif
+
+    // Retrieve the number of high-resolution performance counter ticks per second
+    LARGE_INTEGER frequency;
+    if (!QueryPerformanceFrequency(&frequency)) {
+        counterFrequency = 0;
+    } else {
+        counterFrequency = frequency.QuadPart;
+    }
+
+    done = true;
+}
+
+static inline qint64 ticksToNanoseconds(qint64 ticks)
+{
+    if (counterFrequency > 0) {
+        // QueryPerformanceCounter uses an arbitrary frequency
+        return ticks * 1000000000 / counterFrequency;
+    } else {
+        // GetTickCount(64) return milliseconds
+        return ticks * 1000000;
+    }
+}
+
+static quint64 getTickCount()
+{
+    resolveLibs();
+
+    // This avoids a division by zero and disables the high performance counter if it's not available
+    if (counterFrequency > 0) {
+        LARGE_INTEGER counter;
+
+        if (QueryPerformanceCounter(&counter)) {
+            return counter.QuadPart;
+        } else {
+            qWarning("QueryPerformanceCounter failed, although QueryPerformanceFrequency succeeded.");
+            return 0;
+        }
+    }
+
+    if (ptrGetTickCount64)
+        return ptrGetTickCount64();
+
+    static quint32 highdword = 0;
+    static quint32 lastval = 0;
+    quint32 val = GetTickCount();
+    if (val < lastval)
+        ++highdword;
+    lastval = val;
+    return val | (quint64(highdword) << 32);
+}
+
+QElapsedTimer::ClockType QElapsedTimer::clockType()
+{
+    resolveLibs();
+
+    if (counterFrequency > 0)
+        return PerformanceCounter;
+    else
+        return TickCounter;
+}
+
+bool QElapsedTimer::isMonotonic()
+{
+    return true;
+}
+
+void QElapsedTimer::start()
+{
+    t1 = getTickCount();
+    t2 = 0;
+}
+
+qint64 QElapsedTimer::restart()
+{
+    qint64 oldt1 = t1;
+    t1 = getTickCount();
+    t2 = 0;
+    return ticksToNanoseconds(t1 - oldt1) / 1000000;
+}
+
+qint64 QElapsedTimer::nsecsElapsed() const
+{
+    qint64 elapsed = getTickCount() - t1;
+    return ticksToNanoseconds(elapsed);
+}
+
+qint64 QElapsedTimer::elapsed() const
+{
+    qint64 elapsed = getTickCount() - t1;
+    return ticksToNanoseconds(elapsed) / 1000000;
+}
+
+qint64 QElapsedTimer::msecsSinceReference() const
+{
+    return ticksToNanoseconds(t1) / 1000000;
+}
+
+qint64 QElapsedTimer::msecsTo(const QElapsedTimer &other) const
+{
+    qint64 difference = other.t1 - t1;
+    return ticksToNanoseconds(difference) / 1000000;
+}
+
+qint64 QElapsedTimer::secsTo(const QElapsedTimer &other) const
+{
+    return msecsTo(other) / 1000;
+}
+
+bool operator<(const QElapsedTimer &v1, const QElapsedTimer &v2)
+{
+    return (v1.t1 - v2.t1) < 0;
+}
+
+QT_END_NAMESPACE