Qt-interest Archive, April 2008
Crash in QApplication::topLevelWidgets()
Message 1 in thread
Hi,
I port my application from 3.3.8 to 4.3.4 on Windows XP with VS2005.
I use Qt3Support module. I've got very strange crash in "QWidgetList
QApplication::topLevelWidgets()"
when I call it inside my "customEvent(QEvent *evt)" method . I debug the
Qt sources and see that one of the widget
in the widget list returned by "QApplication::allWidgets()" is a dead
pointer(data=0xffffffff).
How it could happened that "allWidgets()" could possible contain a
pointer to freed memory?
Did I miss something in Qt4 new widget life cycle strategy ?
Thanks,
Vladimir
--
[ signature omitted ]
Message 2 in thread
Hi,
> when I call it inside my "customEvent(QEvent *evt)" method . I debug the
> Qt sources and see that one of the widget
> in the widget list returned by "QApplication::allWidgets()" is a dead
> pointer(data=0xffffffff).
It could be a bug in Qt, or a memory bug in the application. It's hard to tell
without a small compilable example that reproduces the problem.
--
[ signature omitted ]
Message 3 in thread
Is it possible that the widget is deleted yet the event loop has not
been run yet?
Since many widget deletes when not done explicitly, are done via a
deleteLater, it is possible that your getting the system in an
indeterminate state.
While I would nto recommend production code using this, you might want
to try and run
QApplication::processEvents(QEventLoop::ExcludeUserInputEvents )
To see if the object deleted signals get processed first
Scott
> -----Original Message-----
> From: Vladimir Romanovskiy [mailto:3504-214@xxxxxxxxx]
> Sent: Tuesday, April 08, 2008 2:24 PM
> To: qt-interest@xxxxxxxxxxxxx
> Subject: Crash in QApplication::topLevelWidgets()
>
> Hi,
>
> I port my application from 3.3.8 to 4.3.4 on Windows XP with VS2005.
> I use Qt3Support module. I've got very strange crash in "QWidgetList
> QApplication::topLevelWidgets()"
> when I call it inside my "customEvent(QEvent *evt)" method . I debug
> the
> Qt sources and see that one of the widget
> in the widget list returned by "QApplication::allWidgets()" is a dead
> pointer(data=0xffffffff).
>
> How it could happened that "allWidgets()" could possible contain a
> pointer to freed memory?
> Did I miss something in Qt4 new widget life cycle strategy ?
>
> Thanks,
> Vladimir
>
> --
> To unsubscribe - send a mail to qt-interest-request@xxxxxxxxxxxxx with
> "unsubscribe" in the subject or the body.
> List archive and information: http://lists.trolltech.com/qt-interest/
--
[ signature omitted ]
