On Wed, Aug 13, 2014 at 08:37:06AM -0700, Thiago Macieira wrote: > On Wednesday 13 August 2014 17:07:16 Daniel Teske wrote: > > On Wednesday 13 Aug 2014 08:05:52 Thiago Macieira wrote: > > > On Wednesday 13 August 2014 14:32:13 Ziller Eike wrote: > > > > So my question: Does anyone have any idea how this could possibly > > > > happen, > > > > how we could reproduce and/or debug and fix it? > > > > > > I also got a bug report that is similar: > > > https://bugreports.qt-project.org/browse/QTBUG-40636 > > > > > > It's right now in "need info" state. There's nothing I can do with what's > > > reported there or by your backtrace. Any chance we can convince people to > > > run Creator inside valgrind? > > > > > > Also, please store the debug files from the build somewhere. > > > > There is a valgrind log attached to the creator bug. > > Hmm > > ==10972== Invalid read of size 8 > > ==10972== at 0x6528718: QCoreApplication::notifyInternal(QObject*, > QEvent*) > (in /usr/local/Trolltech/5.2.1/gcc_64/lib/libQt5Core.so.5.2.1) > ==10972== Address 0x32c86588 is 8 bytes before a block of size 32 free'd > ==10972== at 0x4C2B60C: free (in /usr/lib/valgrind/vgpreload_memcheck- > amd64-linux.so) > ==10972== by 0x1606157F: CPlusPlus::CreateBindings::~CreateBindings() > (qalgorithms.h:323) > > That doesn't make sense. CPlusPlus::CreateBindings doesn't use any QObject, > so > it shouldn't affect the event processing. > > Theories so far: > 1) bug in QSharedPointer, corrupting the pointer to be freed > 2) bug in QSharedPointer, keeping the pointer past real freeing (dangling > pointer, so it freed something it shouldn't have) > 3) bug in valgrind, reporting bad info > 4) bug in malloc > 5) thread-safety problem
The weird thing is that it's always in QTimerInfoList::activateTimers. Why is it always only QTimerInfo::obj that gets the dangling pointer? Unless it's a thread-safety issue, the only patch that I found since Qt 5.x that could get between ~QObject and QTimerInfoList::unregisterTimers would be : https://codereview.qt-project.org/51304 Though I don't see how this specific patch could be a problem, I was just trying the shotgun approach in git log. Maybe that can give somebody else some idea. Cheers, Jocelyn _______________________________________________ Development mailing list [email protected] http://lists.qt-project.org/mailman/listinfo/development
