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| author | Ahmad Samir <a.samirh78@gmail.com> | 2024-12-19 14:10:31 +0200 |
|---|---|---|
| committer | Ahmad Samir <a.samirh78@gmail.com> | 2025-02-10 01:13:29 +0200 |
| commit | f1f610bc67bfd5c2ef31270a6945e7bae93b5e4a (patch) | |
| tree | 95df313ad5a5a6bd79501073a6f7311a257d1a1b /src/corelib/kernel/qobject.cpp | |
| parent | d4c312f68aee526848b7b2f0e4b77948e8b55e8f (diff) | |
Qt Timers: disallow setting negative intervals
As disccussed in the code review. Replace negative values with 1ms (not
0ms as that would spin up the event-loop too many times).
Move QTimer::start(std::chrono::milliseconds msec) API docs next to the
method definition so as to not forget changing it when the
implementation changes.
Drive-by, qWarning() and co. are marked cold so there is no need to use
Q_UNLIKELY in an if-condition leading to calling these methods.
[ChangeLog][QtCore][Important Behvaior Change] Timers with negative
intervals aren't allowed anymore, that is, if you try to start a timer
(or set the interval) with a negative value, that interval will be set
to 1ms. Previously Qt timers would let you set the interval to a
negative value, but behave in surprising ways (for example stop the
timer if it was running or not start it at all). This change affects
QTimer, QChronoTimer, QBasicTimer and QObject::startTimer().
Fixes: QTBUG-132359
Change-Id: I09309063665db051337f91160971993d9ce7911e
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Diffstat (limited to 'src/corelib/kernel/qobject.cpp')
| -rw-r--r-- | src/corelib/kernel/qobject.cpp | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/src/corelib/kernel/qobject.cpp b/src/corelib/kernel/qobject.cpp index d3566b1081e..707c12ae0fd 100644 --- a/src/corelib/kernel/qobject.cpp +++ b/src/corelib/kernel/qobject.cpp @@ -1821,6 +1821,8 @@ void QObjectPrivate::setThreadData_helper(QThreadData *currentData, QThreadData startTimer(std::chrono::milliseconds{interval}, timerType); \endcode + \include timers-common.qdocinc negative-intervals-not-allowed + \sa timerEvent(), killTimer(), QChronoTimer, QBasicTimer */ @@ -1843,6 +1845,8 @@ int QObject::startTimer(int interval, Qt::TimerType timerType) then the timer event occurs once every time there are no more window system events to process. + \include timers-common.qdocinc negative-intervals-not-allowed + The virtual timerEvent() function is called with the QTimerEvent event parameter class when a timer event occurs. Reimplement this function to get timer events. @@ -1887,9 +1891,10 @@ int QObject::startTimer(std::chrono::nanoseconds interval, Qt::TimerType timerTy using namespace std::chrono_literals; - if (Q_UNLIKELY(interval < 0ns)) { - qWarning("QObject::startTimer: Timers cannot have negative intervals"); - return 0; + if (interval < 0ns) { + qWarning("QObject::startTimer: negative intervals aren't allowed; the " + "interval will be set to 1ms."); + interval = 1ms; } auto thisThreadData = d->threadData.loadRelaxed(); |