1 files changed, 209 insertions, 0 deletions
diff --git a/src/corelib/tools/qelapsedtimer_unix.cpp b/src/corelib/tools/qelapsedtimer_unix.cpp
new file mode 100644
index 0000000000..f24c6fb073
--- /dev/null
+++ b/src/corelib/tools/qelapsedtimer_unix.cpp
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+/****************************************************************************
+**
+** 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 <sys/time.h>
+#include <time.h>
+#include <unistd.h>
+
+#if defined(QT_NO_CLOCK_MONOTONIC) || defined(QT_BOOTSTRAPPED)
+// turn off the monotonic clock
+# ifdef _POSIX_MONOTONIC_CLOCK
+#  undef _POSIX_MONOTONIC_CLOCK
+# endif
+# define _POSIX_MONOTONIC_CLOCK -1
+#endif
+
+QT_BEGIN_NAMESPACE
+
+#if (_POSIX_MONOTONIC_CLOCK-0 != 0)
+static const bool monotonicClockChecked = true;
+static const bool monotonicClockAvailable = _POSIX_MONOTONIC_CLOCK > 0;
+#else
+static int monotonicClockChecked = false;
+static int monotonicClockAvailable = false;
+#endif
+
+#ifdef Q_CC_GNU
+# define is_likely(x) __builtin_expect((x), 1)
+#else
+# define is_likely(x) (x)
+#endif
+#define load_acquire(x) ((volatile const int&)(x))
+#define store_release(x,v) ((volatile int&)(x) = (v))
+
+static void unixCheckClockType()
+{
+#if (_POSIX_MONOTONIC_CLOCK-0 == 0)
+    if (is_likely(load_acquire(monotonicClockChecked)))
+        return;
+
+# if defined(_SC_MONOTONIC_CLOCK)
+    // detect if the system support monotonic timers
+    long x = sysconf(_SC_MONOTONIC_CLOCK);
+    store_release(monotonicClockAvailable, x >= 200112L);
+# endif
+
+    store_release(monotonicClockChecked, true);
+#endif
+}
+
+static inline qint64 fractionAdjustment()
+{
+    // disabled, but otherwise indicates bad usage of QElapsedTimer
+    //Q_ASSERT(monotonicClockChecked);
+
+    if (monotonicClockAvailable) {
+        // the monotonic timer is measured in nanoseconds
+        // 1 ms = 1000000 ns
+        return 1000*1000ull;
+    } else {
+        // gettimeofday is measured in microseconds
+        // 1 ms = 1000 us
+        return 1000;
+    }
+}
+
+bool QElapsedTimer::isMonotonic()
+{
+    unixCheckClockType();
+    return monotonicClockAvailable;
+}
+
+QElapsedTimer::ClockType QElapsedTimer::clockType()
+{
+    unixCheckClockType();
+    return monotonicClockAvailable ? MonotonicClock : SystemTime;
+}
+
+static inline void do_gettime(qint64 *sec, qint64 *frac)
+{
+#if (_POSIX_MONOTONIC_CLOCK-0 >= 0)
+    unixCheckClockType();
+    if (is_likely(monotonicClockAvailable)) {
+        timespec ts;
+        clock_gettime(CLOCK_MONOTONIC, &ts);
+        *sec = ts.tv_sec;
+        *frac = ts.tv_nsec;
+        return;
+    }
+#endif
+    // use gettimeofday
+    timeval tv;
+    ::gettimeofday(&tv, 0);
+    *sec = tv.tv_sec;
+    *frac = tv.tv_usec;
+}
+
+// used in qcore_unix.cpp and qeventdispatcher_unix.cpp
+timeval qt_gettime()
+{
+    qint64 sec, frac;
+    do_gettime(&sec, &frac);
+
+    timeval tv;
+    tv.tv_sec = sec;
+    tv.tv_usec = frac;
+    if (monotonicClockAvailable)
+        tv.tv_usec /= 1000;
+
+    return tv;
+}
+
+static qint64 elapsedAndRestart(qint64 sec, qint64 frac,
+                                qint64 *nowsec, qint64 *nowfrac)
+{
+    do_gettime(nowsec, nowfrac);
+    sec = *nowsec - sec;
+    frac = *nowfrac - frac;
+    return sec * Q_INT64_C(1000) + frac / fractionAdjustment();
+}
+
+void QElapsedTimer::start()
+{
+    do_gettime(&t1, &t2);
+}
+
+qint64 QElapsedTimer::restart()
+{
+    return elapsedAndRestart(t1, t2, &t1, &t2);
+}
+
+qint64 QElapsedTimer::nsecsElapsed() const
+{
+    qint64 sec, frac;
+    do_gettime(&sec, &frac);
+    sec = sec - t1;
+    frac = frac - t2;
+    if (!monotonicClockAvailable)
+        frac *= 1000;
+    return sec * Q_INT64_C(1000000000) + frac;
+}
+
+qint64 QElapsedTimer::elapsed() const
+{
+    qint64 sec, frac;
+    return elapsedAndRestart(t1, t2, &sec, &frac);
+}
+
+qint64 QElapsedTimer::msecsSinceReference() const
+{
+    return t1 * Q_INT64_C(1000) + t2 / fractionAdjustment();
+}
+
+qint64 QElapsedTimer::msecsTo(const QElapsedTimer &other) const
+{
+    qint64 secs = other.t1 - t1;
+    qint64 fraction = other.t2 - t2;
+    return secs * Q_INT64_C(1000) + fraction / fractionAdjustment();
+}
+
+qint64 QElapsedTimer::secsTo(const QElapsedTimer &other) const
+{
+    return other.t1 - t1;
+}
+
+bool operator<(const QElapsedTimer &v1, const QElapsedTimer &v2)
+{
+    return v1.t1 < v2.t1 || (v1.t1 == v2.t1 && v1.t2 < v2.t2);
+}
+
+QT_END_NAMESPACE