Initial import from the monolithic Qt.

This is the beginning of revision history for this module. If you
want to look at revision history older than this, please refer to the
Qt Git wiki for how to use Git history grafting. At the time of
writing, this wiki is located here:

http://qt.gitorious.org/qt/pages/GitIntroductionWithQt

If you have already performed the grafting and you don't see any
history beyond this commit, try running "git log" with the "--follow"
argument.

Branched from the monolithic repo, Qt master branch, at commit
896db169ea224deb96c59ce8af800d019de63f12

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
@@ -0,0 +1,209 @@
+/****************************************************************************
+**
+** 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