Copy QTimer source files to QChronoTimer

Ultimately this is the best way to keep the log history of the code.

Change-Id: I3413deffdb093a3239d65b6ca939e744224e722a
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

6 files changed, 2445 insertions, 0 deletions

diff --git a/src/corelib/kernel/qchronotimer.cpp b/src/corelib/kernel/qchronotimer.cpp
new file mode 100644
index 0000000000..cbeeb97934
--- /dev/null
+++ b/src/corelib/kernel/qchronotimer.cpp
@@ -0,0 +1,646 @@
+// Copyright (C) 2022 The Qt Company Ltd.
+// Copyright (C) 2016 Intel Corporation.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
+
+#include "qtimer.h"
+#include "qtimer_p.h"
+#include "qsingleshottimer_p.h"
+
+#include "qabstracteventdispatcher.h"
+#include "qcoreapplication.h"
+#include "qcoreapplication_p.h"
+#include "qdeadlinetimer.h"
+#include "qmetaobject_p.h"
+#include "qobject_p.h"
+#include "qproperty_p.h"
+#include "qthread.h"
+
+using namespace std::chrono_literals;
+
+QT_BEGIN_NAMESPACE
+
+/*!
+    \class QTimer
+    \inmodule QtCore
+    \brief The QTimer class provides repetitive and single-shot timers.
+
+    \ingroup events
+
+
+    The QTimer class provides a high-level programming interface for
+    timers. To use it, create a QTimer, connect its timeout() signal
+    to the appropriate slots, and call start(). From then on, it will
+    emit the timeout() signal at constant intervals.
+
+    Example for a one second (1000 millisecond) timer (from the
+    \l{widgets/analogclock}{Analog Clock} example):
+
+    \snippet ../widgets/widgets/analogclock/analogclock.cpp 4
+    \snippet ../widgets/widgets/analogclock/analogclock.cpp 5
+    \snippet ../widgets/widgets/analogclock/analogclock.cpp 6
+
+    From then on, the \c update() slot is called every second.
+
+    You can set a timer to time out only once by calling
+    setSingleShot(true). You can also use the static
+    QTimer::singleShot() function to call a slot after a specified
+    interval:
+
+    \snippet timers/timers.cpp 3
+
+    In multithreaded applications, you can use QTimer in any thread
+    that has an event loop. To start an event loop from a non-GUI
+    thread, use QThread::exec(). Qt uses the timer's
+    \l{QObject::thread()}{thread affinity} to determine which thread
+    will emit the \l{QTimer::}{timeout()} signal. Because of this, you
+    must start and stop the timer in its thread; it is not possible to
+    start a timer from another thread.
+
+    As a special case, a QTimer with a timeout of 0 will time out as soon as
+    possible, though the ordering between zero timers and other sources of
+    events is unspecified. Zero timers can be used to do some work while still
+    providing a snappy user interface:
+
+    \snippet timers/timers.cpp 4
+    \snippet timers/timers.cpp 5
+    \snippet timers/timers.cpp 6
+
+    From then on, \c processOneThing() will be called repeatedly. It
+    should be written in such a way that it always returns quickly
+    (typically after processing one data item) so that Qt can deliver
+    events to the user interface and stop the timer as soon as it has done all
+    its work. This is the traditional way of implementing heavy work
+    in GUI applications, but as multithreading is nowadays becoming available on
+    more and more platforms, we expect that zero-millisecond
+    QTimer objects will gradually be replaced by \l{QThread}s.
+
+    \section1 Accuracy and Timer Resolution
+
+    The accuracy of timers depends on the underlying operating system
+    and hardware. Most platforms support a resolution of 1 millisecond,
+    though the accuracy of the timer will not equal this resolution
+    in many real-world situations.
+
+    The accuracy also depends on the \l{Qt::TimerType}{timer type}. For
+    Qt::PreciseTimer, QTimer will try to keep the accuracy at 1 millisecond.
+    Precise timers will also never time out earlier than expected.
+
+    For Qt::CoarseTimer and Qt::VeryCoarseTimer types, QTimer may wake up
+    earlier than expected, within the margins for those types: 5% of the
+    interval for Qt::CoarseTimer and 500 ms for Qt::VeryCoarseTimer.
+
+    All timer types may time out later than expected if the system is busy or
+    unable to provide the requested accuracy. In such a case of timeout
+    overrun, Qt will emit timeout() only once, even if multiple timeouts have
+    expired, and then will resume the original interval.
+
+    \section1 Alternatives to QTimer
+
+    An alternative to using QTimer is to call QObject::startTimer()
+    for your object and reimplement the QObject::timerEvent() event
+    handler in your class (which must inherit QObject). The
+    disadvantage is that timerEvent() does not support such
+    high-level features as single-shot timers or signals.
+
+    Another alternative is QBasicTimer. It is typically less
+    cumbersome than using QObject::startTimer()
+    directly. See \l{Timers} for an overview of all three approaches.
+
+    Some operating systems limit the number of timers that may be
+    used; Qt tries to work around these limitations.
+
+    \sa QBasicTimer, QTimerEvent, QObject::timerEvent(), Timers,
+        {Analog Clock}
+*/
+
+/*!
+    Constructs a timer with the given \a parent.
+*/
+
+QTimer::QTimer(QObject *parent)
+    : QObject(*new QTimerPrivate(this), parent)
+{
+    Q_ASSERT(d_func()->isQTimer);
+}
+
+
+/*!
+    Destroys the timer.
+*/
+
+QTimer::~QTimer()
+{
+    if (d_func()->id != QTimerPrivate::INV_TIMER) // stop running timer
+        stop();
+}
+
+
+/*!
+    \fn void QTimer::timeout()
+
+    This signal is emitted when the timer times out.
+
+    \sa interval, start(), stop()
+*/
+
+/*!
+    \property QTimer::active
+    \since 4.3
+
+    This boolean property is \c true if the timer is running; otherwise
+    false.
+*/
+
+/*!
+    \fn bool QTimer::isActive() const
+
+    Returns \c true if the timer is running (pending); otherwise returns
+    false.
+*/
+bool QTimer::isActive() const
+{
+    return d_func()->isActiveData.value();
+}
+
+QBindable<bool> QTimer::bindableActive()
+{
+    return QBindable<bool>(&d_func()->isActiveData);
+}
+
+/*!
+    \fn int QTimer::timerId() const
+
+    Returns the ID of the timer if the timer is running; otherwise returns
+    -1.
+*/
+int QTimer::timerId() const
+{
+    return d_func()->id;
+}
+
+
+/*! \overload start()
+
+    Starts or restarts the timer with the timeout specified in \l interval.
+
+    If the timer is already running, it will be
+    \l{QTimer::stop()}{stopped} and restarted.
+
+    If \l singleShot is true, the timer will be activated only once.
+*/
+void QTimer::start()
+{
+    Q_D(QTimer);
+    if (d->id != QTimerPrivate::INV_TIMER) // stop running timer
+        stop();
+    const int id = QObject::startTimer(std::chrono::milliseconds{d->inter}, d->type);
+    if (id > 0) {
+        d->id = id;
+        d->isActiveData.notify();
+    }
+}
+
+/*!
+    Starts or restarts the timer with a timeout interval of \a msec
+    milliseconds.
+
+    If the timer is already running, it will be
+    \l{QTimer::stop()}{stopped} and restarted.
+
+    If \l singleShot is true, the timer will be activated only once. This is
+    equivalent to:
+
+    \code
+        timer.setInterval(msec);
+        timer.start();
+    \endcode
+
+    \note   Keeping the event loop busy with a zero-timer is bound to
+            cause trouble and highly erratic behavior of the UI.
+*/
+void QTimer::start(int msec)
+{
+    start(msec * 1ms);
+}
+
+void QTimer::start(std::chrono::milliseconds interval)
+{
+    Q_D(QTimer);
+    // This could be narrowing as the interval is stored in an `int` QProperty,
+    // and the type can't be changed in Qt6.
+    const int msec = interval.count();
+    const bool intervalChanged = msec != d->inter;
+    d->inter.setValue(msec);
+    start();
+    if (intervalChanged)
+        d->inter.notify();
+}
+
+
+
+/*!
+    Stops the timer.
+
+    \sa start()
+*/
+
+void QTimer::stop()
+{
+    Q_D(QTimer);
+    if (d->id != QTimerPrivate::INV_TIMER) {
+        QObject::killTimer(d->id);
+        d->id = QTimerPrivate::INV_TIMER;
+        d->isActiveData.notify();
+    }
+}
+
+
+/*!
+  \reimp
+*/
+void QTimer::timerEvent(QTimerEvent *e)
+{
+    Q_D(QTimer);
+    if (e->timerId() == d->id) {
+        if (d->single)
+            stop();
+        emit timeout(QPrivateSignal());
+    }
+}
+
+/*!
+    \internal
+
+    Implementation of the template version of singleShot
+
+    \a msec is the timer interval
+    \a timerType is the timer type
+    \a receiver is the receiver object, can be null. In such a case, it will be the same
+                as the final sender class.
+    \a slotObj the slot object
+*/
+void QTimer::singleShotImpl(std::chrono::milliseconds msec, Qt::TimerType timerType,
+                            const QObject *receiver,
+                            QtPrivate::QSlotObjectBase *slotObj)
+{
+    if (msec == 0ms) {
+        bool deleteReceiver = false;
+        // Optimize: set a receiver context when none is given, such that we can use
+        // QMetaObject::invokeMethod which is more efficient than going through a timer.
+        // We need a QObject living in the current thread. But the QThread itself lives
+        // in a different thread - with the exception of the main QThread which lives in
+        // itself. And QThread::currentThread() is among the few QObjects we know that will
+        // most certainly be there. Note that one can actually call singleShot before the
+        // QApplication is created!
+        if (!receiver && QThread::currentThread() == QCoreApplicationPrivate::mainThread()) {
+            // reuse main thread as context object
+            receiver = QThread::currentThread();
+        } else if (!receiver) {
+            // Create a receiver context object on-demand. According to the benchmarks,
+            // this is still more efficient than going through a timer.
+            receiver = new QObject;
+            deleteReceiver = true;
+        }
+
+        auto h = QtPrivate::invokeMethodHelper({});
+        QMetaObject::invokeMethodImpl(const_cast<QObject *>(receiver), slotObj,
+                Qt::QueuedConnection, h.parameterCount(), h.parameters.data(), h.typeNames.data(),
+                h.metaTypes.data());
+
+        if (deleteReceiver)
+            const_cast<QObject *>(receiver)->deleteLater();
+        return;
+    }
+
+    new QSingleShotTimer(msec, timerType, receiver, slotObj);
+}
+
+/*!
+    \fn void QTimer::singleShot(int msec, const QObject *receiver, const char *member)
+    \reentrant
+    \deprecated [6.8] Use the chrono overloads.
+    This static function calls a slot after a given time interval.
+
+    It is very convenient to use this function because you do not need
+    to bother with a \l{QObject::timerEvent()}{timerEvent} or
+    create a local QTimer object.
+
+    Example:
+    \snippet code/src_corelib_kernel_qtimer.cpp 0
+
+    This sample program automatically terminates after 10 minutes
+    (600,000 milliseconds).
+
+    The \a receiver is the receiving object and the \a member is the
+    slot. The time interval is \a msec milliseconds.
+
+    \sa start()
+*/
+
+/*!
+    \fn void QTimer::singleShot(int msec, Qt::TimerType timerType, const QObject *receiver, const char *member)
+    \overload
+    \reentrant
+    \deprecated [6.8] Use the chrono overloads.
+    This static function calls a slot after a given time interval.
+
+    It is very convenient to use this function because you do not need
+    to bother with a \l{QObject::timerEvent()}{timerEvent} or
+    create a local QTimer object.
+
+    The \a receiver is the receiving object and the \a member is the slot. The
+    time interval is \a msec milliseconds. The \a timerType affects the
+    accuracy of the timer.
+
+    \sa start()
+*/
+
+void QTimer::singleShot(std::chrono::milliseconds msec, Qt::TimerType timerType,
+                        const QObject *receiver, const char *member)
+{
+    if (Q_UNLIKELY(msec < 0ms)) {
+        qWarning("QTimer::singleShot: Timers cannot have negative timeouts");
+        return;
+    }
+    if (receiver && member) {
+        if (msec == 0ms) {
+            // special code shortpath for 0-timers
+            const char* bracketPosition = strchr(member, '(');
+            if (!bracketPosition || !(member[0] >= '0' && member[0] <= '2')) {
+                qWarning("QTimer::singleShot: Invalid slot specification");
+                return;
+            }
+            const auto methodName = QByteArrayView(member + 1, // extract method name
+                                                   bracketPosition - 1 - member).trimmed();
+            QMetaObject::invokeMethod(const_cast<QObject *>(receiver), methodName.toByteArray().constData(),
+                                      Qt::QueuedConnection);
+            return;
+        }
+        (void) new QSingleShotTimer(msec, timerType, receiver, member);
+    }
+}
+
+/*! \fn template<typename Duration, typename Functor> void QTimer::singleShot(Duration msec, const QObject *context, Functor &&functor)
+    \fn template<typename Duration, typename Functor> void QTimer::singleShot(Duration msec, Qt::TimerType timerType, const QObject *context, Functor &&functor)
+    \fn template<typename Duration, typename Functor> void QTimer::singleShot(Duration msec, Functor &&functor)
+    \fn template<typename Duration, typename Functor> void QTimer::singleShot(Duration msec, Qt::TimerType timerType, Functor &&functor)
+    \since 5.4
+
+    \reentrant
+    This static function calls \a functor after \a msec milliseconds.
+
+    It is very convenient to use this function because you do not need
+    to bother with a \l{QObject::timerEvent()}{timerEvent} or
+    create a local QTimer object.
+
+    If \a context is specified, then the \a functor will be called only if the
+    \a context object has not been destroyed before the interval occurs. The functor
+    will then be run the thread of \a context. The context's thread must have a
+    running Qt event loop.
+
+    If \a functor is a member
+    function of \a context, then the function will be called on the object.
+
+    The \a msec parameter can be an \c int or a \c std::chrono::milliseconds value.
+
+    \sa start()
+*/
+
+/*!
+    \fn void QTimer::singleShot(std::chrono::milliseconds msec, const QObject *receiver, const char *member)
+    \since 5.8
+    \overload
+    \reentrant
+
+    This static function calls a slot after a given time interval.
+
+    It is very convenient to use this function because you do not need
+    to bother with a \l{QObject::timerEvent()}{timerEvent} or
+    create a local QTimer object.
+
+    The \a receiver is the receiving object and the \a member is the slot. The
+    time interval is given in the duration object \a msec.
+
+    \sa start()
+*/
+
+/*!
+    \fn void QTimer::singleShot(std::chrono::milliseconds msec, Qt::TimerType timerType, const QObject *receiver, const char *member)
+    \since 5.8
+    \overload
+    \reentrant
+
+    This static function calls a slot after a given time interval.
+
+    It is very convenient to use this function because you do not need
+    to bother with a \l{QObject::timerEvent()}{timerEvent} or
+    create a local QTimer object.
+
+    The \a receiver is the receiving object and the \a member is the slot. The
+    time interval is given in the duration object \a msec. The \a timerType affects the
+    accuracy of the timer.
+
+    \sa start()
+*/
+
+/*!
+    \fn template <typename Functor> QMetaObject::Connection QTimer::callOnTimeout(Functor &&slot)
+    \since 5.12
+
+    Creates a connection from the timer's timeout() signal to \a slot.
+    Returns a handle to the connection.
+
+    This method is provided for convenience. It's equivalent to calling:
+    \code
+    QObject::connect(timer, &QTimer::timeout, timer, slot, Qt::DirectConnection);
+    \endcode
+
+    \note This overload is not available when \c {QT_NO_CONTEXTLESS_CONNECT} is
+    defined, instead use the callOnTimeout() overload that takes a context object.
+
+    \sa QObject::connect(), timeout()
+*/
+
+/*!
+    \fn template <typename Functor> QMetaObject::Connection QTimer::callOnTimeout(const QObject *context, Functor &&slot, Qt::ConnectionType connectionType = Qt::AutoConnection)
+    \since 5.12
+    \overload callOnTimeout()
+
+    Creates a connection from the timeout() signal to \a slot to be placed in a specific
+    event loop of \a context, and returns a handle to the connection.
+
+    This method is provided for convenience. It's equivalent to calling:
+    \code
+    QObject::connect(timer, &QTimer::timeout, context, slot, connectionType);
+    \endcode
+
+    \sa QObject::connect(), timeout()
+*/
+
+/*!
+    \fn void QTimer::start(std::chrono::milliseconds msec)
+    \since 5.8
+    \overload
+
+    Starts or restarts the timer with a timeout of duration \a msec milliseconds.
+
+    If the timer is already running, it will be
+    \l{QTimer::stop()}{stopped} and restarted.
+
+    If \l singleShot is true, the timer will be activated only once. This is
+    equivalent to:
+
+    \code
+        timer.setInterval(msec);
+        timer.start();
+    \endcode
+*/
+
+/*!
+    \fn std::chrono::milliseconds QTimer::intervalAsDuration() const
+    \since 5.8
+
+    Returns the interval of this timer as a \c std::chrono::milliseconds object.
+
+    \sa interval
+*/
+
+/*!
+    \fn std::chrono::milliseconds QTimer::remainingTimeAsDuration() const
+    \since 5.8
+
+    Returns the time remaining in this timer object as a \c
+    std::chrono::milliseconds object. If this timer is due or overdue, the
+    returned value is \c std::chrono::milliseconds::zero(). If the remaining
+    time could not be found or the timer is not active, this function returns a
+    negative duration.
+
+    \sa remainingTime()
+*/
+
+/*!
+    \property QTimer::singleShot
+    \brief whether the timer is a single-shot timer
+
+    A single-shot timer fires only once, non-single-shot timers fire
+    every \l interval milliseconds.
+
+    The default value for this property is \c false.
+
+    \sa interval, singleShot()
+*/
+void QTimer::setSingleShot(bool singleShot)
+{
+    d_func()->single = singleShot;
+}
+
+bool QTimer::isSingleShot() const
+{
+    return d_func()->single;
+}
+
+QBindable<bool> QTimer::bindableSingleShot()
+{
+    return QBindable<bool>(&d_func()->single);
+}
+
+/*!
+    \property QTimer::interval
+    \brief the timeout interval in milliseconds
+
+    The default value for this property is 0.  A QTimer with a timeout
+    interval of 0 will time out as soon as all the events in the window
+    system's event queue have been processed.
+
+    Setting the interval of an active timer changes its timerId().
+
+    \sa singleShot
+*/
+void QTimer::setInterval(int msec)
+{
+    setInterval(std::chrono::milliseconds{msec});
+}
+
+void QTimer::setInterval(std::chrono::milliseconds interval)
+{
+    Q_D(QTimer);
+    // This could be narrowing as the interval is stored in an `int` QProperty,
+    // and the type can't be changed in Qt6.
+    const int msec = interval.count();
+    d->inter.removeBindingUnlessInWrapper();
+    const bool intervalChanged = msec != d->inter.valueBypassingBindings();
+    d->inter.setValueBypassingBindings(msec);
+    if (d->id != QTimerPrivate::INV_TIMER) { // create new timer
+        QObject::killTimer(d->id);                        // restart timer
+        const int id = QObject::startTimer(std::chrono::milliseconds{msec}, d->type);
+        if (id > 0) {
+            // Restarted successfully. No need to update the active state.
+            d->id = id;
+        } else {
+            // Failed to start the timer.
+            // Need to notify about active state change.
+            d->id = QTimerPrivate::INV_TIMER;
+            d->isActiveData.notify();
+        }
+    }
+    if (intervalChanged)
+        d->inter.notify();
+}
+
+int QTimer::interval() const
+{
+    return d_func()->inter;
+}
+
+QBindable<int> QTimer::bindableInterval()
+{
+    return QBindable<int>(&d_func()->inter);
+}
+
+/*!
+    \property QTimer::remainingTime
+    \since 5.0
+    \brief the remaining time in milliseconds
+
+    Returns the timer's remaining value in milliseconds left until the timeout.
+    If the timer is inactive, the returned value will be -1. If the timer is
+    overdue, the returned value will be 0.
+
+    \sa interval
+*/
+int QTimer::remainingTime() const
+{
+    Q_D(const QTimer);
+    if (d->id != QTimerPrivate::INV_TIMER) {
+        return QAbstractEventDispatcher::instance()->remainingTime(d->id);
+    }
+
+    return -1;
+}
+
+/*!
+    \property QTimer::timerType
+    \brief controls the accuracy of the timer
+
+    The default value for this property is \c Qt::CoarseTimer.
+
+    \sa Qt::TimerType
+*/
+void QTimer::setTimerType(Qt::TimerType atype)
+{
+    d_func()->type = atype;
+}
+
+Qt::TimerType QTimer::timerType() const
+{
+    return d_func()->type;
+}
+
+QBindable<Qt::TimerType> QTimer::bindableTimerType()
+{
+    return QBindable<Qt::TimerType>(&d_func()->type);
+}
+
+QT_END_NAMESPACE
+
+#include "moc_qtimer.cpp"
diff --git a/src/corelib/kernel/qchronotimer.h b/src/corelib/kernel/qchronotimer.h
new file mode 100644
index 0000000000..9b59895e60
--- /dev/null
+++ b/src/corelib/kernel/qchronotimer.h
@@ -0,0 +1,187 @@
+// Copyright (C) 2016 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
+
+#ifndef QTIMER_H
+#define QTIMER_H
+
+#include <QtCore/qglobal.h>
+
+#ifndef QT_NO_QOBJECT
+
+#include <QtCore/qbasictimer.h> // conceptual inheritance
+#include <QtCore/qobject.h>
+
+#include <chrono>
+
+QT_BEGIN_NAMESPACE
+
+class QTimerPrivate;
+class Q_CORE_EXPORT QTimer : public QObject
+{
+    Q_OBJECT
+    Q_PROPERTY(bool singleShot READ isSingleShot WRITE setSingleShot BINDABLE bindableSingleShot)
+    Q_PROPERTY(int interval READ interval WRITE setInterval BINDABLE bindableInterval)
+    Q_PROPERTY(int remainingTime READ remainingTime)
+    Q_PROPERTY(Qt::TimerType timerType READ timerType WRITE setTimerType BINDABLE bindableTimerType)
+    Q_PROPERTY(bool active READ isActive STORED false BINDABLE bindableActive)
+public:
+    explicit QTimer(QObject *parent = nullptr);
+    ~QTimer();
+
+    bool isActive() const;
+    QBindable<bool> bindableActive();
+    int timerId() const;
+
+    void setInterval(int msec);
+    int interval() const;
+    QBindable<int> bindableInterval();
+
+    int remainingTime() const;
+
+    void setTimerType(Qt::TimerType atype);
+    Qt::TimerType timerType() const;
+    QBindable<Qt::TimerType> bindableTimerType();
+
+    void setSingleShot(bool singleShot);
+    bool isSingleShot() const;
+    QBindable<bool> bindableSingleShot();
+
+    QT_CORE_INLINE_SINCE(6, 8)
+    static void singleShot(int msec, const QObject *receiver, const char *member);
+
+    QT_CORE_INLINE_SINCE(6, 8)
+    static void singleShot(int msec, Qt::TimerType timerType, const QObject *receiver, const char *member);
+
+    // singleShot with context
+#ifdef Q_QDOC
+    template <typename Duration, typename Functor>
+    static inline void singleShot(Duration interval, const QObject *receiver, Functor &&slot);
+    template <typename Duration, typename Functor>
+    static inline void singleShot(Duration interval, Qt::TimerType timerType,
+                                  const QObject *receiver, Functor &&slot);
+#else
+    template <typename Duration, typename Functor>
+    static inline void singleShot(Duration interval,
+                                  const typename QtPrivate::ContextTypeForFunctor<Functor>::ContextType *receiver,
+                                  Functor &&slot)
+    {
+        singleShot(interval, defaultTypeFor(interval), receiver, std::forward<Functor>(slot));
+    }
+    template <typename Duration, typename Functor>
+    static inline void singleShot(Duration interval, Qt::TimerType timerType,
+                                  const typename QtPrivate::ContextTypeForFunctor<Functor>::ContextType *receiver,
+                                  Functor &&slot)
+    {
+        using Prototype = void(*)();
+        singleShotImpl(interval, timerType, receiver,
+                       QtPrivate::makeCallableObject<Prototype>(std::forward<Functor>(slot)));
+    }
+#endif
+
+    // singleShot without context
+    template <typename Duration, typename Functor>
+    static inline void singleShot(Duration interval, Functor &&slot)
+    {
+        singleShot(interval, defaultTypeFor(interval), nullptr, std::forward<Functor>(slot));
+    }
+    template <typename Duration, typename Functor>
+    static inline void singleShot(Duration interval, Qt::TimerType timerType, Functor &&slot)
+    {
+        singleShot(interval, timerType, nullptr, std::forward<Functor>(slot));
+    }
+
+#ifdef Q_QDOC
+    template <typename Functor>
+    QMetaObject::Connection callOnTimeout(Functor &&slot);
+    template <typename Functor>
+    QMetaObject::Connection callOnTimeout(const QObject *context, Functor &&slot, Qt::ConnectionType connectionType = Qt::AutoConnection);
+#else
+    template <typename ... Args>
+    QMetaObject::Connection callOnTimeout(Args && ...args)
+    {
+        return QObject::connect(this, &QTimer::timeout, std::forward<Args>(args)... );
+    }
+
+#endif
+
+public Q_SLOTS:
+    void start(int msec);
+
+    void start();
+    void stop();
+
+Q_SIGNALS:
+    void timeout(QPrivateSignal);
+
+public:
+    void setInterval(std::chrono::milliseconds value);
+
+    std::chrono::milliseconds intervalAsDuration() const
+    {
+        return std::chrono::milliseconds(interval());
+    }
+
+    std::chrono::milliseconds remainingTimeAsDuration() const
+    {
+        return std::chrono::milliseconds(remainingTime());
+    }
+
+    static void singleShot(std::chrono::milliseconds value, const QObject *receiver, const char *member)
+    {
+        singleShot(value, defaultTypeFor(value), receiver, member);
+    }
+    static void singleShot(std::chrono::milliseconds interval, Qt::TimerType timerType,
+                           const QObject *receiver, const char *member);
+
+    void start(std::chrono::milliseconds value);
+
+protected:
+    void timerEvent(QTimerEvent *) override;
+
+private:
+    Q_DISABLE_COPY(QTimer)
+    Q_DECLARE_PRIVATE(QTimer)
+
+    inline int startTimer(int){ return -1;}
+    inline void killTimer(int){}
+
+    static constexpr Qt::TimerType defaultTypeFor(int msecs) noexcept
+    { return defaultTypeFor(std::chrono::milliseconds{msecs}); }
+
+    static constexpr Qt::TimerType defaultTypeFor(std::chrono::milliseconds interval) noexcept
+    {
+        // coarse timers are worst in their first firing
+        // so we prefer a high precision timer for something that happens only once
+        // unless the timeout is too big, in which case we go for coarse anyway
+        using namespace std::chrono_literals;
+        return interval >= 2s ? Qt::CoarseTimer : Qt::PreciseTimer;
+    }
+
+    QT_CORE_INLINE_SINCE(6, 8)
+    static void singleShotImpl(int msec, Qt::TimerType timerType,
+                               const QObject *receiver, QtPrivate::QSlotObjectBase *slotObj);
+
+    static void singleShotImpl(std::chrono::milliseconds interval, Qt::TimerType timerType,
+                               const QObject *receiver, QtPrivate::QSlotObjectBase *slotObj);
+};
+
+#if QT_CORE_INLINE_IMPL_SINCE(6, 8)
+void QTimer::singleShot(int msec, const QObject *receiver, const char *member)
+{ singleShot(std::chrono::milliseconds{msec}, receiver, member); }
+
+void QTimer::singleShot(int msec, Qt::TimerType timerType, const QObject *receiver,
+                        const char *member)
+{ singleShot(std::chrono::milliseconds{msec}, timerType, receiver, member); }
+
+void QTimer::singleShotImpl(int msec, Qt::TimerType timerType,
+                            const QObject *receiver, QtPrivate::QSlotObjectBase *slotObj)
+{
+    singleShotImpl(std::chrono::milliseconds{msec}, timerType, receiver, slotObj);
+}
+#endif
+
+QT_END_NAMESPACE
+
+#endif // QT_NO_QOBJECT
+
+#endif // QTIMER_H
diff --git a/tests/auto/corelib/kernel/qchronotimer/.gitignore b/tests/auto/corelib/kernel/qchronotimer/.gitignore
new file mode 100644
index 0000000000..14fd00629e
--- /dev/null
+++ b/tests/auto/corelib/kernel/qchronotimer/.gitignore
@@ -0,0 +1 @@
+tst_qtimer
diff --git a/tests/auto/corelib/kernel/qchronotimer/CMakeLists.txt b/tests/auto/corelib/kernel/qchronotimer/CMakeLists.txt
new file mode 100644
index 0000000000..6bb3b15850
--- /dev/null
+++ b/tests/auto/corelib/kernel/qchronotimer/CMakeLists.txt
@@ -0,0 +1,34 @@
+# Copyright (C) 2022 The Qt Company Ltd.
+# SPDX-License-Identifier: BSD-3-Clause
+
+if(NOT QT_BUILD_STANDALONE_TESTS AND NOT QT_BUILDING_QT)
+    cmake_minimum_required(VERSION 3.16)
+    project(tst_qtimer LANGUAGES CXX)
+    find_package(Qt6BuildInternals REQUIRED COMPONENTS STANDALONE_TEST)
+endif()
+
+if (NOT QT_FEATURE_thread)
+    return()
+endif()
+
+function(addTimerTest test)
+    qt_internal_add_test(${test}
+        SOURCES
+            tst_qtimer.cpp
+        LIBRARIES
+            Qt::CorePrivate
+            Qt::TestPrivate
+    )
+endfunction()
+
+addTimerTest(tst_qtimer)
+
+if(QT_FEATURE_glib AND UNIX)
+    addTimerTest(tst_qtimer_no_glib)
+    qt_internal_extend_target(tst_qtimer_no_glib
+        DEFINES
+            DISABLE_GLIB
+            tst_QTimer=tst_QTimer_no_glib # Class name in the unittest
+    )
+endif()
+
diff --git a/tests/auto/corelib/kernel/qchronotimer/tst_qchronotimer.cpp b/tests/auto/corelib/kernel/qchronotimer/tst_qchronotimer.cpp
new file mode 100644
index 0000000000..467fc9abd7
--- /dev/null
+++ b/tests/auto/corelib/kernel/qchronotimer/tst_qchronotimer.cpp
@@ -0,0 +1,1539 @@
+// Copyright (C) 2020 The Qt Company Ltd.
+// Copyright (C) 2016 Intel Corporation.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only
+
+/* WARNING: this source-code is reused by another test.
+
+   As Qt built with GUI support may use a different backend for its event loops
+   and other timer-related matters, it is important to test it in that form, as
+   well as in its GUI-less form. So this source file is reused by a build config
+   in the GUI module. Similarly, testing with and without glib is supported,
+   where relevant (see DISABLE_GLIB below).
+*/
+#ifdef QT_GUI_LIB
+// When compiled as tests/auto/gui/kernel/qguitimer/'s source-code:
+#  include <QtGui/QGuiApplication>
+#else
+// When compiled as tests/auto/corelib/kernel/qtimer/'s source-code:
+#  include <QtCore/QCoreApplication>
+#endif
+
+#include <QtCore/private/qglobal_p.h>
+#include <QTest>
+#include <QSignalSpy>
+#include <QtTest/private/qpropertytesthelper_p.h>
+
+#include <qtimer.h>
+#include <qthread.h>
+#include <qelapsedtimer.h>
+#include <qproperty.h>
+
+#if defined Q_OS_UNIX
+#include <unistd.h>
+#endif
+
+#ifdef DISABLE_GLIB
+static bool glibDisabled = []() {
+    qputenv("QT_NO_GLIB", "1");
+    return true;
+}();
+#endif
+
+using namespace std::chrono_literals;
+
+class tst_QTimer : public QObject
+{
+    Q_OBJECT
+public:
+    static void initMain();
+
+private slots:
+    void cleanupTestCase();
+    void zeroTimer();
+    void singleShotTimeout();
+    void timeout();
+    void singleShotNormalizes_data();
+    void singleShotNormalizes();
+    void sequentialTimers_data();
+    void sequentialTimers();
+    void singleShotSequentialTimers_data();
+    void singleShotSequentialTimers();
+    void remainingTime();
+    void remainingTimeInitial_data();
+    void remainingTimeInitial();
+    void remainingTimeDuringActivation_data();
+    void remainingTimeDuringActivation();
+    void basic_chrono();
+    void livelock_data();
+    void livelock();
+    void timerInfiniteRecursion_data();
+    void timerInfiniteRecursion();
+    void recurringTimer_data();
+    void recurringTimer();
+    void deleteLaterOnQTimer(); // long name, don't want to shadow QObject::deleteLater()
+    void moveToThread();
+    void restartedTimerFiresTooSoon();
+    void timerFiresOnlyOncePerProcessEvents_data();
+    void timerFiresOnlyOncePerProcessEvents();
+    void timerIdPersistsAfterThreadExit();
+    void cancelLongTimer();
+    void singleShotStaticFunctionZeroTimeout();
+    void recurseOnTimeoutAndStopTimer();
+    void singleShotToFunctors();
+    void singleShot_chrono();
+    void singleShot_static();
+    void crossThreadSingleShotToFunctor_data();
+    void crossThreadSingleShotToFunctor();
+    void timerOrder();
+    void timerOrder_data();
+    void timerOrderBackgroundThread();
+    void timerOrderBackgroundThread_data() { timerOrder_data(); }
+
+    void dontBlockEvents();
+    void postedEventsShouldNotStarveTimers();
+    void callOnTimeout();
+
+    void bindToTimer();
+    void bindTimer();
+    void automatedBindingTests();
+
+    void negativeInterval();
+};
+
+void tst_QTimer::zeroTimer()
+{
+    QTimer timer;
+    QVERIFY(!timer.isSingleShot());
+    timer.setInterval(0);
+    timer.setSingleShot(true);
+    QVERIFY(timer.isSingleShot());
+
+    QSignalSpy timeoutSpy(&timer, &QTimer::timeout);
+    timer.start();
+
+    // Pass timeout to work round glib issue, see QTBUG-84291.
+    QCoreApplication::processEvents(QEventLoop::AllEvents, INT_MAX);
+
+    QCOMPARE(timeoutSpy.size(), 1);
+}
+
+void tst_QTimer::singleShotTimeout()
+{
+    QTimer timer;
+    QVERIFY(!timer.isSingleShot());
+    timer.setSingleShot(true);
+    QVERIFY(timer.isSingleShot());
+
+    QSignalSpy timeoutSpy(&timer, &QTimer::timeout);
+    timer.start(100);
+
+    QVERIFY(timeoutSpy.wait(500));
+    QCOMPARE(timeoutSpy.size(), 1);
+    QTest::qWait(500);
+    QCOMPARE(timeoutSpy.size(), 1);
+}
+
+#define TIMEOUT_TIMEOUT 200
+
+void tst_QTimer::timeout()
+{
+    QTimer timer;
+    QSignalSpy timeoutSpy(&timer, &QTimer::timeout);
+    timer.start(100);
+
+    QCOMPARE(timeoutSpy.size(), 0);
+
+    QTRY_VERIFY_WITH_TIMEOUT(timeoutSpy.size() > 0, TIMEOUT_TIMEOUT);
+    int oldCount = timeoutSpy.size();
+
+    QTRY_VERIFY_WITH_TIMEOUT(timeoutSpy.size() > oldCount, TIMEOUT_TIMEOUT);
+}
+
+void tst_QTimer::singleShotNormalizes_data()
+{
+    QTest::addColumn<QByteArray>("slotName");
+
+    QTest::newRow("normalized") << QByteArray(SLOT(exitLoop()));
+
+    QTest::newRow("space-before") << QByteArray(SLOT( exitLoop()));
+    QTest::newRow("space-after") << QByteArray(SLOT(exitLoop ()));
+    QTest::newRow("space-around") << QByteArray(SLOT( exitLoop ()));
+    QTest::newRow("spaces-before") << QByteArray(SLOT(  exitLoop()));
+    QTest::newRow("spaces-after") << QByteArray(SLOT(exitLoop  ()));
+    QTest::newRow("spaces-around") << QByteArray(SLOT(  exitLoop  ()));
+
+    QTest::newRow("space-in-parens") << QByteArray(SLOT(exitLoop( )));
+    QTest::newRow("spaces-in-parens") << QByteArray(SLOT(exitLoop(  )));
+    QTest::newRow("space-after-parens") << QByteArray(SLOT(exitLoop() ));
+    QTest::newRow("spaces-after-parens") << QByteArray(SLOT(exitLoop()  ));
+}
+
+void tst_QTimer::singleShotNormalizes()
+{
+    static constexpr auto TestTimeout = 250ms;
+    QFETCH(QByteArray, slotName);
+    QEventLoop loop;
+
+    // control test: regular connection
+    {
+        QTimer timer;
+        QVERIFY(QObject::connect(&timer, SIGNAL(timeout()), &QTestEventLoop::instance(), slotName));
+        timer.setSingleShot(true);
+        timer.start(1);
+        QTestEventLoop::instance().enterLoop(TestTimeout);
+        QVERIFY(!QTestEventLoop::instance().timeout());
+    }
+
+    // non-zero time
+    QTimer::singleShot(1, &QTestEventLoop::instance(), slotName);
+    QTestEventLoop::instance().enterLoop(TestTimeout);
+    QVERIFY(!QTestEventLoop::instance().timeout());
+
+    QTimer::singleShot(1ms, &QTestEventLoop::instance(), slotName);
+    QTestEventLoop::instance().enterLoop(TestTimeout);
+    QVERIFY(!QTestEventLoop::instance().timeout());
+
+    // zero time
+    QTimer::singleShot(0, &QTestEventLoop::instance(), slotName);
+    QTestEventLoop::instance().enterLoop(TestTimeout);
+    QVERIFY(!QTestEventLoop::instance().timeout());
+
+    QTimer::singleShot(0ms, &QTestEventLoop::instance(), slotName);
+    QTestEventLoop::instance().enterLoop(TestTimeout);
+    QVERIFY(!QTestEventLoop::instance().timeout());
+}
+
+void tst_QTimer::sequentialTimers_data()
+{
+#ifdef Q_OS_WIN
+    QSKIP("The API used by QEventDispatcherWin32 doesn't respect the order");
+#endif
+    QTest::addColumn<QList<int>>("timeouts");
+    auto addRow = [](const QList<int> &l) {
+        QByteArray name;
+        int last = -1;
+        for (int i = 0; i < l.size(); ++i) {
+            Q_ASSERT_X(l[i] >= last, "tst_QTimer", "input list must be sorted");
+            name += QByteArray::number(l[i]) + ',';
+        }
+        name.chop(1);
+        QTest::addRow("%s", name.constData()) << l;
+    };
+    // PreciseTimers
+    addRow({0, 0, 0, 0, 0, 0});
+    addRow({0, 1, 2});
+    addRow({1, 1, 1, 2, 2, 2, 2});
+    addRow({1, 2, 3});
+    addRow({19, 19, 19});
+    // CoarseTimer for setInterval
+    addRow({20, 20, 20, 20, 20});
+    addRow({25, 25, 25, 25, 25, 25, 50});
+}
+
+void tst_QTimer::sequentialTimers()
+{
+    QFETCH(const QList<int>, timeouts);
+    QByteArray result, expected;
+    std::vector<std::unique_ptr<QTimer>> timers;
+    expected.resize(timeouts.size());
+    result.reserve(timeouts.size());
+    timers.reserve(timeouts.size());
+    for (int i = 0; i < timeouts.size(); ++i) {
+        auto timer = std::make_unique<QTimer>();
+        timer->setSingleShot(true);
+        timer->setInterval(timeouts[i]);
+
+        char c = 'A' + i;
+        expected[i] = c;
+        QObject::connect(timer.get(), &QTimer::timeout, this, [&result, c = c]() {
+            result.append(c);
+        });
+        timers.push_back(std::move(timer));
+    }
+
+    // start the timers
+    for (auto &timer : timers)
+        timer->start();
+
+    QTestEventLoop::instance().enterLoopMSecs(timeouts.last() * 2 + 10);
+
+    QCOMPARE(result, expected);
+}
+
+void tst_QTimer::singleShotSequentialTimers_data()
+{
+    sequentialTimers_data();
+}
+
+void tst_QTimer::singleShotSequentialTimers()
+{
+    QFETCH(const QList<int>, timeouts);
+    QByteArray result, expected;
+    expected.resize(timeouts.size());
+    result.reserve(timeouts.size());
+    for (int i = 0; i < timeouts.size(); ++i) {
+        char c = 'A' + i;
+        expected[i] = c;
+        QTimer::singleShot(timeouts[i], this, [&result, c = c]() {
+            result.append(c);
+        });
+    }
+
+    QTestEventLoop::instance().enterLoopMSecs(timeouts.last() * 2 + 10);
+
+    QCOMPARE(result, expected);
+}
+
+void tst_QTimer::remainingTime()
+{
+    QTimer tested;
+    tested.setTimerType(Qt::PreciseTimer);
+
+    QTimer tester;
+    tester.setTimerType(Qt::PreciseTimer);
+    tester.setSingleShot(true);
+
+    const int testedInterval = 200;
+    const int testerInterval = 50;
+    const int expectedRemainingTime = testedInterval - testerInterval;
+
+    int testIteration = 0;
+    const int desiredTestCount = 2;
+
+    auto connection = QObject::connect(&tested, &QTimer::timeout, [&tester]() {
+        // We let tested (which isn't a single-shot) run repeatedly, to verify
+        // it *does* repeat, and check that the single-shot tester, starting
+        // at the same time, does finish first each time, by about the right duration.
+        tester.start(); // Start tester again.
+    });
+
+    QObject::connect(&tester, &QTimer::timeout, [&]() {
+        const int remainingTime = tested.remainingTime();
+        // We expect that remainingTime is at most 150 and not overdue.
+        const bool remainingTimeInRange = remainingTime > 0
+                                       && remainingTime <= expectedRemainingTime;
+        if (remainingTimeInRange)
+            ++testIteration;
+        else
+            testIteration = desiredTestCount; // We are going to fail on QVERIFY2()
+                                              // below, so we don't want to iterate
+                                              // anymore and quickly exit the QTRY_...()
+                                              // with this failure.
+        if (testIteration == desiredTestCount)
+            QObject::disconnect(connection); // Last iteration, don't start tester again.
+        QVERIFY2(remainingTimeInRange, qPrintable("Remaining time "
+                 + QByteArray::number(remainingTime) + "ms outside expected range (0ms, "
+                 + QByteArray::number(expectedRemainingTime) + "ms]"));
+    });
+
+    tested.start(testedInterval);
+    tester.start(testerInterval); // Start tester for the 1st time.
+
+    // Test it desiredTestCount times, give it reasonable amount of time
+    // (twice as much as needed).
+    QTRY_COMPARE_WITH_TIMEOUT(testIteration, desiredTestCount,
+                              testedInterval * desiredTestCount * 2);
+}
+
+void tst_QTimer::remainingTimeInitial_data()
+{
+    QTest::addColumn<int>("startTimeMs");
+    QTest::addColumn<Qt::TimerType>("timerType");
+
+    QTest::addRow("precise time 0ms") << 0 << Qt::PreciseTimer;
+    QTest::addRow("precise time 1ms") << 1 << Qt::PreciseTimer;
+    QTest::addRow("precise time 10ms") << 10 << Qt::PreciseTimer;
+
+    QTest::addRow("coarse time 0ms") << 0 << Qt::CoarseTimer;
+    QTest::addRow("coarse time 1ms") << 1 << Qt::CoarseTimer;
+    QTest::addRow("coarse time 10ms") << 10 << Qt::CoarseTimer;
+}
+
+void tst_QTimer::remainingTimeInitial()
+{
+    QFETCH(int, startTimeMs);
+    QFETCH(Qt::TimerType, timerType);
+
+    QTimer timer;
+    QCOMPARE(timer.timerType(), Qt::CoarseTimer);
+    timer.setTimerType(timerType);
+    QCOMPARE(timer.timerType(), timerType);
+    timer.start(startTimeMs);
+
+    const int rt = timer.remainingTime();
+    QVERIFY2(rt >= 0 && rt <= startTimeMs, qPrintable(QString::number(rt)));
+}
+
+void tst_QTimer::remainingTimeDuringActivation_data()
+{
+    QTest::addColumn<bool>("singleShot");
+    QTest::newRow("repeating") << false;
+    QTest::newRow("single-shot") << true;
+}
+
+void tst_QTimer::remainingTimeDuringActivation()
+{
+    QFETCH(bool, singleShot);
+
+    QTimer timer;
+    timer.setSingleShot(singleShot);
+
+    int remainingTime = 0; // not the expected value in either case
+    connect(&timer, &QTimer::timeout,
+            [&]() {
+                remainingTime = timer.remainingTime();
+            });
+    QSignalSpy timeoutSpy(&timer, &QTimer::timeout);
+    const int timeout = 20; // 20 ms is short enough and should not round down to 0 in any timer mode
+    timer.start(timeout);
+
+    QVERIFY(timeoutSpy.wait());
+    if (singleShot)
+        QCOMPARE(remainingTime, -1);     // timer not running
+    else
+        QVERIFY2(remainingTime <= timeout && remainingTime > 0,
+                 qPrintable(QString::number(remainingTime)));
+
+    if (!singleShot) {
+        // do it again - see QTBUG-46940
+        remainingTime = -1;
+        QVERIFY(timeoutSpy.wait());
+        QVERIFY2(remainingTime <= timeout && remainingTime > 0,
+                 qPrintable(QString::number(remainingTime)));
+    }
+}
+
+namespace {
+
+    template <typename T>
+    std::chrono::milliseconds to_ms(T t)
+    { return std::chrono::duration_cast<std::chrono::milliseconds>(t); }
+
+} // unnamed namespace
+
+void tst_QTimer::basic_chrono()
+{
+    // duplicates zeroTimer, singleShotTimeout, interval and remainingTime
+    using namespace std::chrono;
+    QTimer timer;
+    QSignalSpy timeoutSpy(&timer, &QTimer::timeout);
+    timer.setInterval(to_ms(nanoseconds(0)));
+    timer.start();
+    QCOMPARE(timer.intervalAsDuration().count(), milliseconds::rep(0));
+    QCOMPARE(timer.remainingTimeAsDuration().count(), milliseconds::rep(0));
+
+    QCoreApplication::processEvents();
+
+    QCOMPARE(timeoutSpy.size(), 1);
+
+    timeoutSpy.clear();
+    timer.start(milliseconds(100));
+    QCOMPARE(timeoutSpy.size(), 0);
+
+    QVERIFY(timeoutSpy.wait(TIMEOUT_TIMEOUT));
+    QVERIFY(timeoutSpy.size() > 0);
+    int oldCount = timeoutSpy.size();
+
+    QVERIFY(timeoutSpy.wait(TIMEOUT_TIMEOUT));
+    QVERIFY(timeoutSpy.size() > oldCount);
+
+    timeoutSpy.clear();
+    timer.start(to_ms(microseconds(200000)));
+    QCOMPARE(timer.intervalAsDuration().count(), milliseconds::rep(200));
+    QTest::qWait(50);
+    QCOMPARE(timeoutSpy.size(), 0);
+
+    milliseconds rt = timer.remainingTimeAsDuration();
+    QVERIFY2(rt.count() >= 50 && rt.count() <= 200, qPrintable(QString::number(rt.count())));
+
+    timeoutSpy.clear();
+    timer.setSingleShot(true);
+    timer.start(milliseconds(100));
+    QVERIFY(timeoutSpy.wait(TIMEOUT_TIMEOUT));
+    QCOMPARE(timeoutSpy.size(), 1);
+    QTest::qWait(500);
+    QCOMPARE(timeoutSpy.size(), 1);
+}
+
+void tst_QTimer::livelock_data()
+{
+    QTest::addColumn<int>("interval");
+    QTest::newRow("zero timer") << 0;
+    QTest::newRow("non-zero timer") << 1;
+    QTest::newRow("longer than sleep") << 20;
+}
+
+/*!
+ *
+ * DO NOT "FIX" THIS TEST!  it is written like this for a reason, do
+ * not *change it without first dicussing it with its maintainers.
+ *
+*/
+class LiveLockTester : public QObject
+{
+public:
+    LiveLockTester(int i)
+        : interval(i),
+          timeoutsForFirst(0), timeoutsForExtra(0), timeoutsForSecond(0),
+          postEventAtRightTime(false)
+    {
+        firstTimerId = startTimer(interval);
+        extraTimerId = startTimer(interval + 80);
+        secondTimerId = -1; // started later
+    }
+
+    bool event(QEvent *e) override
+    {
+        if (e->type() == 4002) {
+            // got the posted event
+            if (timeoutsForFirst == 1 && timeoutsForSecond == 0)
+                postEventAtRightTime = true;
+            return true;
+        }
+        return QObject::event(e);
+    }
+
+    void timerEvent(QTimerEvent *te) override
+    {
+        if (te->timerId() == firstTimerId) {
+            if (++timeoutsForFirst == 1) {
+                killTimer(extraTimerId);
+                extraTimerId = -1;
+                QCoreApplication::postEvent(this, new QEvent(static_cast<QEvent::Type>(4002)));
+                secondTimerId = startTimer(interval);
+            }
+        } else if (te->timerId() == secondTimerId) {
+            ++timeoutsForSecond;
+        } else if (te->timerId() == extraTimerId) {
+            ++timeoutsForExtra;
+        }
+
+        // sleep for 2ms
+        QTest::qSleep(2);
+        killTimer(te->timerId());
+    }
+
+    const int interval;
+    int firstTimerId;
+    int secondTimerId;
+    int extraTimerId;
+    int timeoutsForFirst;
+    int timeoutsForExtra;
+    int timeoutsForSecond;
+    bool postEventAtRightTime;
+};
+
+void tst_QTimer::livelock()
+{
+    /*
+      New timers created in timer event handlers should not be sent
+      until the next iteration of the eventloop.  Note: this test
+      depends on the fact that we send posted events before timer
+      events (since new posted events are not sent until the next
+      iteration of the eventloop either).
+    */
+    QFETCH(int, interval);
+    LiveLockTester tester(interval);
+    QTest::qWait(180); // we have to use wait here, since we're testing timers with a non-zero timeout
+    QTRY_COMPARE(tester.timeoutsForFirst, 1);
+    QCOMPARE(tester.timeoutsForExtra, 0);
+    QTRY_COMPARE(tester.timeoutsForSecond, 1);
+    QVERIFY(tester.postEventAtRightTime);
+}
+
+class TimerInfiniteRecursionObject : public QObject
+{
+public:
+    bool inTimerEvent;
+    bool timerEventRecursed;
+    int interval;
+
+    TimerInfiniteRecursionObject(int interval)
+        : inTimerEvent(false), timerEventRecursed(false), interval(interval)
+    { }
+
+    void timerEvent(QTimerEvent *timerEvent) override
+    {
+        timerEventRecursed = inTimerEvent;
+        if (timerEventRecursed) {
+            // bug detected!
+            return;
+        }
+
+        inTimerEvent = true;
+
+        QEventLoop eventLoop;
+        QTimer::singleShot(qMax(100, interval * 2), &eventLoop, SLOT(quit()));
+        eventLoop.exec();
+
+        inTimerEvent = false;
+
+        killTimer(timerEvent->timerId());
+    }
+};
+
+void tst_QTimer::timerInfiniteRecursion_data()
+{
+    QTest::addColumn<int>("interval");
+    QTest::newRow("zero timer") << 0;
+    QTest::newRow("non-zero timer") << 1;
+    QTest::newRow("10ms timer") << 10;
+    QTest::newRow("11ms timer") << 11;
+    QTest::newRow("100ms timer") << 100;
+    QTest::newRow("1s timer") << 1000;
+}
+
+
+void tst_QTimer::timerInfiniteRecursion()
+{
+    QFETCH(int, interval);
+    TimerInfiniteRecursionObject object(interval);
+    (void) object.startTimer(interval);
+
+    QEventLoop eventLoop;
+    QTimer::singleShot(qMax(100, interval * 2), &eventLoop, SLOT(quit()));
+    eventLoop.exec();
+
+    QVERIFY(!object.timerEventRecursed);
+}
+
+class RecurringTimerObject : public QObject
+{
+Q_OBJECT
+public:
+    int times;
+    int target;
+    bool recurse;
+
+    RecurringTimerObject(int target)
+        : times(0), target(target), recurse(false)
+    { }
+
+    void timerEvent(QTimerEvent *timerEvent) override
+    {
+        if (++times == target) {
+            killTimer(timerEvent->timerId());
+            emit done();
+        } if (recurse) {
+            QEventLoop eventLoop;
+            QTimer::singleShot(100, &eventLoop, SLOT(quit()));
+            eventLoop.exec();
+        }
+    }
+
+signals:
+    void done();
+};
+
+void tst_QTimer::recurringTimer_data()
+{
+    QTest::addColumn<int>("interval");
+    QTest::addColumn<bool>("recurse");
+    // make sure that eventloop recursion doesn't affect timer recurrence
+    QTest::newRow("zero timer, don't recurse") << 0 << false;
+    QTest::newRow("zero timer, recurse") << 0 << true;
+    QTest::newRow("non-zero timer, don't recurse") << 1 << false;
+    QTest::newRow("non-zero timer, recurse") << 1 << true;
+}
+
+void tst_QTimer::recurringTimer()
+{
+    const int target = 5;
+    QFETCH(int, interval);
+    QFETCH(bool, recurse);
+
+    RecurringTimerObject object(target);
+    object.recurse = recurse;
+    QSignalSpy doneSpy(&object, &RecurringTimerObject::done);
+
+    (void) object.startTimer(interval);
+    QVERIFY(doneSpy.wait());
+
+    QCOMPARE(object.times, target);
+}
+
+void tst_QTimer::deleteLaterOnQTimer()
+{
+    QTimer *timer = new QTimer;
+    connect(timer, SIGNAL(timeout()), timer, SLOT(deleteLater()));
+    QSignalSpy destroyedSpy(timer, &QObject::destroyed);
+    timer->setInterval(1);
+    timer->setSingleShot(true);
+    timer->start();
+    QPointer<QTimer> pointer = timer;
+    QVERIFY(destroyedSpy.wait());
+    QVERIFY(pointer.isNull());
+}
+
+#define MOVETOTHREAD_TIMEOUT 200
+#define MOVETOTHREAD_WAIT 300
+
+void tst_QTimer::moveToThread()
+{
+#if defined(Q_OS_WIN32)
+    QSKIP("Does not work reliably on Windows :(");
+#elif defined(Q_OS_MACOS)
+    QSKIP("Does not work reliably on macOS 10.12+ (QTBUG-59679)");
+#endif
+    QTimer ti1;
+    QTimer ti2;
+    ti1.setSingleShot(true);
+    ti1.start(MOVETOTHREAD_TIMEOUT);
+    ti2.start(MOVETOTHREAD_TIMEOUT);
+    QVERIFY((ti1.timerId() & 0xffffff) != (ti2.timerId() & 0xffffff));
+    QThread tr;
+    ti1.moveToThread(&tr);
+    connect(&ti1,SIGNAL(timeout()), &tr, SLOT(quit()));
+    tr.start();
+    QTimer ti3;
+    ti3.start(MOVETOTHREAD_TIMEOUT);
+    QVERIFY((ti3.timerId() & 0xffffff) != (ti2.timerId() & 0xffffff));
+    QVERIFY((ti3.timerId() & 0xffffff) != (ti1.timerId() & 0xffffff));
+    QTest::qWait(MOVETOTHREAD_WAIT);
+    QVERIFY(tr.wait());
+    ti2.stop();
+    QTimer ti4;
+    ti4.start(MOVETOTHREAD_TIMEOUT);
+    ti3.stop();
+    ti2.start(MOVETOTHREAD_TIMEOUT);
+    ti3.start(MOVETOTHREAD_TIMEOUT);
+    QVERIFY((ti4.timerId() & 0xffffff) != (ti2.timerId() & 0xffffff));
+    QVERIFY((ti3.timerId() & 0xffffff) != (ti2.timerId() & 0xffffff));
+    QVERIFY((ti3.timerId() & 0xffffff) != (ti1.timerId() & 0xffffff));
+}
+
+class RestartedTimerFiresTooSoonObject : public QObject
+{
+    Q_OBJECT
+
+public:
+    QBasicTimer m_timer;
+
+    int m_interval;
+    QElapsedTimer m_elapsedTimer;
+    QEventLoop eventLoop;
+
+    inline RestartedTimerFiresTooSoonObject()
+        : QObject(), m_interval(0)
+    { }
+
+    void timerFired()
+    {
+        static int interval = 1000;
+
+        m_interval = interval;
+        m_elapsedTimer.start();
+        m_timer.start(interval, this);
+
+        // alternate between single-shot and 1 sec
+        interval = interval ? 0 : 1000;
+    }
+
+    void timerEvent(QTimerEvent* ev) override
+    {
+        if (ev->timerId() != m_timer.timerId())
+            return;
+
+        m_timer.stop();
+
+        int elapsed = m_elapsedTimer.elapsed();
+
+        if (elapsed < m_interval / 2) {
+            // severely too early!
+            m_timer.stop();
+            eventLoop.exit(-1);
+            return;
+        }
+
+        timerFired();
+
+        // don't do this forever
+        static int count = 0;
+        if (count++ > 20) {
+            m_timer.stop();
+            eventLoop.quit();
+            return;
+        }
+    }
+};
+
+void tst_QTimer::restartedTimerFiresTooSoon()
+{
+    RestartedTimerFiresTooSoonObject object;
+    object.timerFired();
+    QCOMPARE(object.eventLoop.exec(), 0);
+}
+
+class LongLastingSlotClass : public QObject
+{
+    Q_OBJECT
+
+public:
+    LongLastingSlotClass(QTimer *timer) : count(0), timer(timer) {}
+
+public slots:
+    void longLastingSlot()
+    {
+        // Don't use QTimer for this, because we are testing it.
+        QElapsedTimer control;
+        control.start();
+        while (control.elapsed() < 200) {
+            for (int c = 0; c < 100000; c++) {} // Mindless looping.
+        }
+        if (++count >= 2) {
+            timer->stop();
+        }
+    }
+
+public:
+    int count;
+    QTimer *timer;
+};
+
+void tst_QTimer::timerFiresOnlyOncePerProcessEvents_data()
+{
+    QTest::addColumn<int>("interval");
+    QTest::newRow("zero timer") << 0;
+    QTest::newRow("non-zero timer") << 10;
+}
+
+void tst_QTimer::timerFiresOnlyOncePerProcessEvents()
+{
+    QFETCH(int, interval);
+
+    QTimer t;
+    LongLastingSlotClass longSlot(&t);
+    t.start(interval);
+    connect(&t, SIGNAL(timeout()), &longSlot, SLOT(longLastingSlot()));
+    // Loop because there may be other events pending.
+    while (longSlot.count == 0) {
+        QCoreApplication::processEvents(QEventLoop::WaitForMoreEvents);
+    }
+
+    QCOMPARE(longSlot.count, 1);
+}
+
+class TimerIdPersistsAfterThreadExitThread : public QThread
+{
+public:
+    QTimer *timer;
+    int timerId, returnValue;
+
+    TimerIdPersistsAfterThreadExitThread()
+        : QThread(), timer(0), timerId(-1), returnValue(-1)
+    { }
+    ~TimerIdPersistsAfterThreadExitThread()
+    {
+        delete timer;
+    }
+
+    void run() override
+    {
+        QEventLoop eventLoop;
+        timer = new QTimer;
+        connect(timer, SIGNAL(timeout()), &eventLoop, SLOT(quit()));
+        timer->start(100);
+        timerId = timer->timerId();
+        returnValue = eventLoop.exec();
+    }
+};
+
+void tst_QTimer::timerIdPersistsAfterThreadExit()
+{
+    TimerIdPersistsAfterThreadExitThread thread;
+    thread.start();
+    QVERIFY(thread.wait(30000));
+    QCOMPARE(thread.returnValue, 0);
+
+    // even though the thread has exited, and the event dispatcher destroyed, the timer is still
+    // "active", meaning the timer id should NOT be reused (i.e. the event dispatcher should not
+    // have unregistered it)
+    int timerId = thread.startTimer(100);
+    QVERIFY((timerId & 0xffffff) != (thread.timerId & 0xffffff));
+}
+
+void tst_QTimer::cancelLongTimer()
+{
+    QTimer timer;
+    timer.setSingleShot(true);
+    timer.start(1000 * 60 * 60); //set timer for 1 hour
+    QCoreApplication::processEvents();
+    QVERIFY(timer.isActive()); //if the timer completes immediately with an error, then this will fail
+    timer.stop();
+    QVERIFY(!timer.isActive());
+}
+
+class TimeoutCounter : public QObject
+{
+    Q_OBJECT
+public slots:
+    void timeout() { ++count; };
+public:
+    int count = 0;
+};
+
+void tst_QTimer::singleShotStaticFunctionZeroTimeout()
+{
+    {
+        TimeoutCounter counter;
+
+        QTimer::singleShot(0, &counter, SLOT(timeout()));
+        QTRY_COMPARE(counter.count, 1);
+        QTest::qWait(500);
+        QCOMPARE(counter.count, 1);
+    }
+
+    {
+        TimeoutCounter counter;
+
+        QTimer::singleShot(0, &counter, &TimeoutCounter::timeout);
+        QTRY_COMPARE(counter.count, 1);
+        QTest::qWait(500);
+        QCOMPARE(counter.count, 1);
+    }
+}
+
+class RecursOnTimeoutAndStopTimerTimer : public QObject
+{
+    Q_OBJECT
+
+public:
+    QTimer *one;
+    QTimer *two;
+
+public slots:
+    void onetrigger()
+    {
+        QCoreApplication::processEvents();
+    }
+
+    void twotrigger()
+    {
+        one->stop();
+    }
+};
+
+void tst_QTimer::recurseOnTimeoutAndStopTimer()
+{
+    QEventLoop eventLoop;
+    QTimer::singleShot(1000, &eventLoop, SLOT(quit()));
+
+    RecursOnTimeoutAndStopTimerTimer t;
+    t.one = new QTimer(&t);
+    t.two = new QTimer(&t);
+
+    QObject::connect(t.one, SIGNAL(timeout()), &t, SLOT(onetrigger()));
+    QObject::connect(t.two, SIGNAL(timeout()), &t, SLOT(twotrigger()));
+
+    t.two->setSingleShot(true);
+
+    t.one->start();
+    t.two->start();
+
+    (void) eventLoop.exec();
+
+    QVERIFY(!t.one->isActive());
+    QVERIFY(!t.two->isActive());
+}
+
+struct CountedStruct
+{
+    CountedStruct(int *count, QThread *t = nullptr) : count(count), thread(t) { }
+    ~CountedStruct() { }
+    void operator()() const { ++(*count); if (thread) QCOMPARE(QThread::currentThread(), thread); }
+
+    int *count;
+    QThread *thread;
+};
+
+static QScopedPointer<QEventLoop> _e;
+static QThread *_t = nullptr;
+
+class StaticEventLoop
+{
+public:
+    static void quitEventLoop()
+    {
+        quitEventLoop_noexcept();
+    }
+
+    static void quitEventLoop_noexcept() noexcept
+    {
+        QVERIFY(!_e.isNull());
+        _e->quit();
+        if (_t)
+            QCOMPARE(QThread::currentThread(), _t);
+    }
+};
+
+void tst_QTimer::singleShotToFunctors()
+{
+    int count = 0;
+    _e.reset(new QEventLoop);
+    QEventLoop e;
+
+    QTimer::singleShot(0, CountedStruct(&count));
+    QCoreApplication::processEvents();
+    QCOMPARE(count, 1);
+
+    QTimer::singleShot(0, &StaticEventLoop::quitEventLoop);
+    QCOMPARE(_e->exec(), 0);
+
+    QTimer::singleShot(0, &StaticEventLoop::quitEventLoop_noexcept);
+    QCOMPARE(_e->exec(), 0);
+
+    QThread t1;
+    QObject c1;
+    c1.moveToThread(&t1);
+
+    QObject::connect(&t1, SIGNAL(started()), &e, SLOT(quit()));
+    t1.start();
+    QCOMPARE(e.exec(), 0);
+
+    QTimer::singleShot(0, &c1, CountedStruct(&count, &t1));
+    QTRY_COMPARE(count, 2);
+
+    t1.quit();
+    t1.wait();
+
+    _t = new QThread;
+    QObject c2;
+    c2.moveToThread(_t);
+
+    QObject::connect(_t, SIGNAL(started()), &e, SLOT(quit()));
+    _t->start();
+    QCOMPARE(e.exec(), 0);
+
+    QTimer::singleShot(0, &c2, &StaticEventLoop::quitEventLoop);
+    QCOMPARE(_e->exec(), 0);
+
+    _t->quit();
+    _t->wait();
+    _t->deleteLater();
+    _t = nullptr;
+
+    {
+        QObject c3;
+        QTimer::singleShot(500, &c3, CountedStruct(&count));
+    }
+    QTest::qWait(800); // Wait until the singleshot timer would have timed out
+    QCOMPARE(count, 2);
+
+    QTimer::singleShot(0, [&count] { ++count; });
+    QTRY_COMPARE(count, 3);
+
+    QObject context;
+    QThread thread;
+
+    context.moveToThread(&thread);
+    QObject::connect(&thread, SIGNAL(started()), &e, SLOT(quit()));
+    thread.start();
+    QCOMPARE(e.exec(), 0);
+
+    QTimer::singleShot(0, &context, [&count, &thread] { ++count; QCOMPARE(QThread::currentThread(), &thread); });
+    QTRY_COMPARE(count, 4);
+
+    thread.quit();
+    thread.wait();
+
+    struct MoveOnly : CountedStruct {
+        Q_DISABLE_COPY(MoveOnly)
+        MoveOnly(MoveOnly &&o) : CountedStruct(std::move(o)) {};
+        MoveOnly(int *c) : CountedStruct(c) {}
+    };
+    QTimer::singleShot(0, MoveOnly(&count));
+    QTRY_COMPARE(count, 5);
+
+    _e.reset();
+    _t = nullptr;
+}
+
+void tst_QTimer::singleShot_chrono()
+{
+    // duplicates singleShotStaticFunctionZeroTimeout and singleShotToFunctors
+    using namespace std::chrono;
+    {
+        TimeoutCounter counter;
+
+        QTimer::singleShot(hours(0), &counter, SLOT(timeout()));
+        QTRY_COMPARE(counter.count, 1);
+        QTest::qWait(500);
+        QCOMPARE(counter.count, 1);
+    }
+
+    {
+        TimeoutCounter counter;
+
+        QTimer::singleShot(hours(0), &counter, &TimeoutCounter::timeout);
+        QTRY_COMPARE(counter.count, 1);
+        QTest::qWait(500);
+        QCOMPARE(counter.count, 1);
+    }
+
+    int count = 0;
+    QTimer::singleShot(to_ms(microseconds(0)), CountedStruct(&count));
+    QTRY_COMPARE(count, 1);
+
+    _e.reset(new QEventLoop);
+    QTimer::singleShot(0, &StaticEventLoop::quitEventLoop);
+    QCOMPARE(_e->exec(), 0);
+
+    QObject c3;
+    QTimer::singleShot(milliseconds(500), &c3, CountedStruct(&count));
+    QTRY_COMPARE(count, 2);
+
+    QTimer::singleShot(0, [&count] { ++count; });
+    QTRY_COMPARE(count, 3);
+
+    _e.reset();
+}
+
+class DontBlockEvents : public QObject
+{
+    Q_OBJECT
+public:
+    DontBlockEvents();
+    void timerEvent(QTimerEvent*) override;
+
+    int count;
+    int total;
+    QBasicTimer m_timer;
+
+public slots:
+    void paintEvent();
+
+};
+
+DontBlockEvents::DontBlockEvents()
+{
+    count = 0;
+    total = 0;
+
+    // need a few unrelated timers running to reproduce the bug.
+    (new QTimer(this))->start(2000);
+    (new QTimer(this))->start(2500);
+    (new QTimer(this))->start(3000);
+    (new QTimer(this))->start(5000);
+    (new QTimer(this))->start(1000);
+    (new QTimer(this))->start(2000);
+
+    m_timer.start(1, this);
+}
+
+void DontBlockEvents::timerEvent(QTimerEvent* event)
+{
+    if (event->timerId() == m_timer.timerId()) {
+        QMetaObject::invokeMethod(this, "paintEvent", Qt::QueuedConnection);
+        m_timer.start(0, this);
+        count++;
+        QCOMPARE(count, 1);
+        total++;
+    }
+}
+
+void DontBlockEvents::paintEvent()
+{
+    count--;
+    QCOMPARE(count, 0);
+}
+
+// This is a regression test for QTBUG-13633, where a timer with a zero
+// timeout that was restarted by the event handler could starve other timers.
+void tst_QTimer::dontBlockEvents()
+{
+    DontBlockEvents t;
+    QTest::qWait(60);
+    QTRY_VERIFY(t.total > 2);
+}
+
+class SlotRepeater : public QObject {
+    Q_OBJECT
+public:
+    SlotRepeater() {}
+
+public slots:
+    void repeatThisSlot()
+    {
+        QMetaObject::invokeMethod(this, "repeatThisSlot", Qt::QueuedConnection);
+    }
+};
+
+void tst_QTimer::postedEventsShouldNotStarveTimers()
+{
+    QTimer timer;
+    timer.setInterval(0);
+    timer.setSingleShot(false);
+    QSignalSpy timeoutSpy(&timer, &QTimer::timeout);
+    timer.start();
+    SlotRepeater slotRepeater;
+    slotRepeater.repeatThisSlot();
+    QTRY_VERIFY_WITH_TIMEOUT(timeoutSpy.size() > 5, 100);
+}
+
+struct DummyFunctor {
+    static QThread *callThread;
+    void operator()() {
+        callThread = QThread::currentThread();
+        callThread->quit();
+    }
+};
+QThread *DummyFunctor::callThread = nullptr;
+
+void tst_QTimer::crossThreadSingleShotToFunctor_data()
+{
+    QTest::addColumn<int>("timeout");
+
+    QTest::addRow("zero-timer") << 0;
+    QTest::addRow("1ms") << 1;
+}
+
+void tst_QTimer::crossThreadSingleShotToFunctor()
+{
+    QFETCH(int, timeout);
+    // We're also testing for crashes here, so the test simply running to
+    // completion is part of the success
+    DummyFunctor::callThread = nullptr;
+
+    QThread t;
+    std::unique_ptr<QObject> o(new QObject());
+    o->moveToThread(&t);
+
+    QTimer::singleShot(timeout, o.get(), DummyFunctor());
+
+    // wait enough time for the timer to have timed out before the timer
+    // could be start in the receiver's thread.
+    QTest::qWait(10 + timeout * 10);
+    t.start();
+    t.wait();
+    QCOMPARE(DummyFunctor::callThread, &t);
+
+    // continue with a stress test - the calling thread is busy, the
+    // timer should still fire and no crashes.
+    DummyFunctor::callThread = nullptr;
+    t.start();
+    for (int i = 0; i < 10000; i++)
+        QTimer::singleShot(timeout, o.get(), DummyFunctor());
+
+    t.wait();
+    o.reset();
+
+    QCOMPARE(DummyFunctor::callThread, &t);
+}
+
+void tst_QTimer::callOnTimeout()
+{
+    QTimer timer;
+    QSignalSpy timeoutSpy(&timer, &QTimer::timeout);
+    timer.setInterval(0);
+    timer.start();
+
+    auto context = new QObject();
+
+    int count = 0;
+    timer.callOnTimeout([&count] { count++; });
+    QMetaObject::Connection connection = timer.callOnTimeout(context, [&count] { count++; });
+    timer.callOnTimeout(&timer, &QTimer::stop);
+
+
+    QTest::qWait(100);
+    QCOMPARE(count, 2);
+    QCOMPARE(timeoutSpy.size(), 1);
+
+    // Test that connection is bound to context lifetime
+    QVERIFY(connection);
+    delete context;
+    QVERIFY(!connection);
+}
+
+void tst_QTimer::bindToTimer()
+{
+    QTimer timer;
+
+    // singleShot property
+    QProperty<bool> singleShot;
+    singleShot.setBinding(timer.bindableSingleShot().makeBinding());
+    QCOMPARE(timer.isSingleShot(), singleShot);
+
+    timer.setSingleShot(true);
+    QVERIFY(singleShot);
+    timer.setSingleShot(false);
+    QVERIFY(!singleShot);
+
+    // interval property
+    QProperty<int> interval;
+    interval.setBinding([&](){ return timer.interval(); });
+    QCOMPARE(timer.interval(), interval);
+
+    timer.setInterval(10);
+    QCOMPARE(interval, 10);
+    timer.setInterval(100);
+    QCOMPARE(interval, 100);
+
+    // timerType property
+    QProperty<Qt::TimerType> timerType;
+    timerType.setBinding(timer.bindableTimerType().makeBinding());
+    QCOMPARE(timer.timerType(), timerType);
+
+    timer.setTimerType(Qt::PreciseTimer);
+    QCOMPARE(timerType, Qt::PreciseTimer);
+
+    timer.setTimerType(Qt::VeryCoarseTimer);
+    QCOMPARE(timerType, Qt::VeryCoarseTimer);
+
+    // active property
+    QProperty<bool> active;
+    active.setBinding([&](){ return timer.isActive(); });
+    QCOMPARE(active, timer.isActive());
+
+    timer.start(1000);
+    QVERIFY(active);
+
+    timer.stop();
+    QVERIFY(!active);
+
+    auto ignoreMsg = [] {
+        QTest::ignoreMessage(QtWarningMsg,
+                             "QObject::startTimer: Timers cannot have negative intervals");
+    };
+
+    // also test that using negative interval updates the binding correctly
+    timer.start(100);
+    QVERIFY(active);
+    ignoreMsg();
+    timer.setInterval(-100);
+    QVERIFY(!active);
+    timer.start(100);
+    QVERIFY(active);
+    ignoreMsg();
+    timer.start(-100);
+    QVERIFY(!active);
+}
+
+void tst_QTimer::bindTimer()
+{
+    QTimer timer;
+
+    // singleShot property
+    QVERIFY(!timer.isSingleShot());
+
+    QProperty<bool> singleShot;
+    timer.bindableSingleShot().setBinding(Qt::makePropertyBinding(singleShot));
+
+    singleShot = true;
+    QVERIFY(timer.isSingleShot());
+    singleShot = false;
+    QVERIFY(!timer.isSingleShot());
+
+    // interval property
+    QCOMPARE(timer.interval(), 0);
+
+    QProperty<int> interval;
+    timer.bindableInterval().setBinding(Qt::makePropertyBinding(interval));
+
+    interval = 10;
+    QCOMPARE(timer.interval(), 10);
+    interval = 100;
+    QCOMPARE(timer.interval(), 100);
+    timer.setInterval(50);
+    QCOMPARE(timer.interval(), 50);
+    interval = 30;
+    QCOMPARE(timer.interval(), 50);
+
+    // timerType property
+    QCOMPARE(timer.timerType(), Qt::CoarseTimer);
+
+    QProperty<Qt::TimerType> timerType;
+    timer.bindableTimerType().setBinding(Qt::makePropertyBinding(timerType));
+
+    timerType = Qt::PreciseTimer;
+    QCOMPARE(timer.timerType(), Qt::PreciseTimer);
+    timerType = Qt::VeryCoarseTimer;
+    QCOMPARE(timer.timerType(), Qt::VeryCoarseTimer);
+}
+
+void tst_QTimer::automatedBindingTests()
+{
+    QTimer timer;
+
+    QVERIFY(!timer.isSingleShot());
+    QTestPrivate::testReadWritePropertyBasics(timer, true, false, "singleShot");
+    if (QTest::currentTestFailed()) {
+        qDebug("Failed property test for QTimer::singleShot");
+        return;
+    }
+
+    QCOMPARE_NE(timer.interval(), 10);
+    QTestPrivate::testReadWritePropertyBasics(timer, 10, 20, "interval");
+    if (QTest::currentTestFailed()) {
+        qDebug("Failed property test for QTimer::interval");
+        return;
+    }
+
+    QCOMPARE_NE(timer.timerType(), Qt::PreciseTimer);
+    QTestPrivate::testReadWritePropertyBasics(timer, Qt::PreciseTimer, Qt::CoarseTimer,
+                                              "timerType");
+    if (QTest::currentTestFailed()) {
+        qDebug("Failed property test for QTimer::timerType");
+        return;
+    }
+
+    timer.start(1000);
+    QVERIFY(timer.isActive());
+    QTestPrivate::testReadOnlyPropertyBasics(timer, true, false, "active",
+                                             [&timer]() { timer.stop(); });
+    if (QTest::currentTestFailed()) {
+        qDebug("Failed property test for QTimer::active");
+        return;
+    }
+}
+
+void tst_QTimer::negativeInterval()
+{
+    auto ignoreMsg = [] {
+        QTest::ignoreMessage(QtWarningMsg,
+                             "QObject::startTimer: Timers cannot have negative intervals");
+    };
+
+    QTimer timer;
+
+    // Starting with a negative interval does not change active state.
+    ignoreMsg();
+    timer.start(-100ms);
+    QVERIFY(!timer.isActive());
+
+    // Updating the interval to a negative value stops the timer and changes
+    // the active state.
+    timer.start(100ms);
+    QVERIFY(timer.isActive());
+    ignoreMsg();
+    timer.setInterval(-100);
+    QVERIFY(!timer.isActive());
+
+    // Starting with a negative interval when already started leads to stop
+    // and inactive state.
+    timer.start(100);
+    QVERIFY(timer.isActive());
+    ignoreMsg();
+    timer.start(-100ms);
+    QVERIFY(!timer.isActive());
+}
+
+class OrderHelper : public QObject
+{
+    Q_OBJECT
+public:
+    enum CallType
+    {
+        String,
+        PMF,
+        Functor,
+        FunctorNoCtx
+    };
+    Q_ENUM(CallType)
+    QList<CallType> calls;
+
+    void triggerCall(CallType callType)
+    {
+        switch (callType)
+        {
+        case String:
+            QTimer::singleShot(0, this, SLOT(stringSlot()));
+            break;
+        case PMF:
+            QTimer::singleShot(0, this, &OrderHelper::pmfSlot);
+            break;
+        case Functor:
+            QTimer::singleShot(0, this, [this]() { functorSlot(); });
+            break;
+        case FunctorNoCtx:
+            QTimer::singleShot(0, [this]() { functorNoCtxSlot(); });
+            break;
+        }
+    }
+
+public slots:
+    void stringSlot() { calls << String; }
+    void pmfSlot() { calls << PMF; }
+    void functorSlot() { calls << Functor; }
+    void functorNoCtxSlot() { calls << FunctorNoCtx; }
+};
+
+Q_DECLARE_METATYPE(OrderHelper::CallType)
+
+void tst_QTimer::timerOrder()
+{
+    QFETCH(QList<OrderHelper::CallType>, calls);
+
+    OrderHelper helper;
+
+    for (const auto call : calls)
+        helper.triggerCall(call);
+
+    QTRY_COMPARE(helper.calls, calls);
+}
+
+void tst_QTimer::timerOrder_data()
+{
+    QTest::addColumn<QList<OrderHelper::CallType>>("calls");
+
+    QList<OrderHelper::CallType> calls = {
+        OrderHelper::String, OrderHelper::PMF,
+        OrderHelper::Functor, OrderHelper::FunctorNoCtx
+    };
+    std::sort(calls.begin(), calls.end());
+
+    int permutation = 0;
+    do {
+        QTest::addRow("permutation=%d", permutation) << calls;
+        ++permutation;
+    } while (std::next_permutation(calls.begin(), calls.end()));
+}
+
+void tst_QTimer::timerOrderBackgroundThread()
+{
+    auto *thread = QThread::create([this]() { timerOrder(); });
+    thread->start();
+    QVERIFY(thread->wait());
+    delete thread;
+}
+
+struct StaticSingleShotUser
+{
+    StaticSingleShotUser()
+    {
+        for (auto call : calls())
+            helper.triggerCall(call);
+    }
+    OrderHelper helper;
+
+    static QList<OrderHelper::CallType> calls()
+    {
+        return {OrderHelper::String, OrderHelper::PMF,
+                OrderHelper::Functor, OrderHelper::FunctorNoCtx};
+    }
+};
+
+// NOTE: to prevent any static initialization order fiasco, we implement
+//       initMain() to instantiate staticSingleShotUser before qApp
+
+static StaticSingleShotUser *s_staticSingleShotUser = nullptr;
+
+void tst_QTimer::initMain()
+{
+    s_staticSingleShotUser = new StaticSingleShotUser;
+}
+
+void tst_QTimer::cleanupTestCase()
+{
+    delete s_staticSingleShotUser;
+}
+
+void tst_QTimer::singleShot_static()
+{
+    QCoreApplication::processEvents();
+    QCOMPARE(s_staticSingleShotUser->helper.calls, s_staticSingleShotUser->calls());
+}
+
+QTEST_MAIN(tst_QTimer)
+
+#include "tst_qtimer.moc"
diff --git a/tests/auto/gui/kernel/qguichronotimer/CMakeLists.txt b/tests/auto/gui/kernel/qguichronotimer/CMakeLists.txt
new file mode 100644
index 0000000000..bc292e133b
--- /dev/null
+++ b/tests/auto/gui/kernel/qguichronotimer/CMakeLists.txt
@@ -0,0 +1,38 @@
+# Copyright (C) 2022 The Qt Company Ltd.
+# SPDX-License-Identifier: BSD-3-Clause
+
+#####################################################################
+## tst_qguitimer Test:
+#####################################################################
+
+if(NOT QT_BUILD_STANDALONE_TESTS AND NOT QT_BUILDING_QT)
+    cmake_minimum_required(VERSION 3.16)
+    project(tst_qguitimer LANGUAGES CXX)
+    find_package(Qt6BuildInternals REQUIRED COMPONENTS STANDALONE_TEST)
+endif()
+
+function(addGuiTimerTest test)
+    qt_internal_add_test(${test}
+        SOURCES
+            ../../../corelib/kernel/qtimer/tst_qtimer.cpp
+        LIBRARIES
+            Qt::CorePrivate
+            Qt::Gui
+            Qt::TestPrivate
+    )
+endfunction()
+
+addGuiTimerTest(tst_qguitimer)
+qt_internal_extend_target(tst_qguitimer
+    DEFINES
+        tst_Qtimer=tst_QGuiTimer
+)
+
+if(QT_FEATURE_glib AND UNIX)
+    addGuiTimerTest(tst_qguitimer_no_glib)
+    qt_internal_extend_target(tst_qguitimer_no_glib
+        DEFINES
+            DISABLE_GLIB
+            tst_QTimer=tst_QGuiTimer_no_glib # Class name in the unittest
+    )
+endif()