Details
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Bug
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Resolution: Done
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P1: Critical
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5.3.0 Beta1, 5.3.0
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Windows 7 (x64). Also observed on QNX.
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a560018d08d4212bc65c163eb608639f19b38df2 (qtdeclarative)
Description
Observed a crash when creating new QML Components from C++. Verified that object ownership was correct.
Did a stack trace and discovered that in qv4qobjectwrapper.cpp markChildQObjectsRecursively() we are attempting to dereference a NULL child pointer. I know that the QML parent of these children is being destroyed via a call to destroy() in QML and was dynamically created. So when I look at the QList of children one step up in the recursive stack all the children are null.
Will include the stack trace. It is difficult to provide example code because this is buried in a proprietary C++ class. It is also not reproducible 100% of the time, only about 80% in my case. This indicates that an element of timing may be involved so here is the timeline in my code that leads to the crash:
1. A "Page" is being destroyed.
2. When one of the components on the page is set to null it triggers a binding in an external component which changes its model.
3. The model change causes the external component to re-create its delegates (which happens in C++). During the beginCreate() call (and occasionally during the completeCreate() call) garbage collection is triggered and seems to be trying to garbage collect my entire application. When I followed the recursive marking up to the top, the first QObject without a parent that is being garbage collected is the QML component in my main.qml file.
Could be related to https://bugreports.qt-project.org/browse/QTBUG-36183
Stack Backtrace:
0 QScopedPointer<QObjectData,QScopedPointerDeleter<QObjectData> >::data qscopedpointer.h 143 0x59f7277a 1 qGetPtrHelper<QScopedPointer<QObjectData,QScopedPointerDeleter<QObjectData> > > qglobal.h 938 0x59f69b4b 2 QObject::d_func qobject.h 118 0x59f6fc23 3 QObjectPrivate::get qobject_p.h 200 0x59f6c47b 4 QQmlData::get qqmldata_p.h 196 0x656adb30 5 markChildQObjectsRecursively qv4qobjectwrapper.cpp 958 0x658de1fd 6 markChildQObjectsRecursively qv4qobjectwrapper.cpp 961 0x658de225 7 markChildQObjectsRecursively qv4qobjectwrapper.cpp 961 0x658de225 8 markChildQObjectsRecursively qv4qobjectwrapper.cpp 961 0x658de225 9 markChildQObjectsRecursively qv4qobjectwrapper.cpp 961 0x658de225 10 QV4::QObjectWrapper::markObjects qv4qobjectwrapper.cpp 979 0x658de18b 11 QV4::MemoryManager::mark qv4mm.cpp 312 0x65868733 12 QV4::MemoryManager::runGC qv4mm.cpp 440 0x65868bf4 13 QV4::MemoryManager::alloc qv4mm.cpp 207 0x658682d3 14 QV4::MemoryManager::allocManaged qv4mm_p.h 102 0x657b4614 15 QV4::Members::ensureIndex qv4memberdata.cpp 78 0x65899fb0 16 QV4::Object::ensureMemberIndex qv4object.cpp 232 0x6589c1df 17 QV4::Object::insertMember qv4object.cpp 242 0x6589c22f 18 QV4::SimpleScriptFunction::SimpleScriptFunction qv4functionobject.cpp 458 0x658885bc 19 QV4::FunctionObject::createScriptFunction qv4functionobject.cpp 183 0x658870ee 20 QQmlObjectCreator::setPropertyBinding qqmlobjectcreator.cpp 823 0x659c9c51 21 QQmlObjectCreator::setupBindings qqmlobjectcreator.cpp 724 0x659c94b5 22 QQmlObjectCreator::populateInstance qqmlobjectcreator.cpp 1316 0x659cc182 23 QQmlObjectCreator::createInstance qqmlobjectcreator.cpp 1158 0x659cb7f9 24 QQmlObjectCreator::setPropertyBinding qqmlobjectcreator.cpp 765 0x659c9887 25 QQmlObjectCreator::setupBindings qqmlobjectcreator.cpp 724 0x659c94b5 26 QQmlObjectCreator::populateInstance qqmlobjectcreator.cpp 1316 0x659cc182 27 QQmlObjectCreator::createInstance qqmlobjectcreator.cpp 1158 0x659cb7f9 28 QQmlObjectCreator::create qqmlobjectcreator.cpp 219 0x659c6cc3 29 QQmlObjectCreator::createInstance qqmlobjectcreator.cpp 1075 0x659cb1c9 30 QQmlObjectCreator::create qqmlobjectcreator.cpp 219 0x659c6cc3 31 QQmlObjectCreator::createInstance qqmlobjectcreator.cpp 1075 0x659cb1c9 32 QQmlObjectCreator::setPropertyBinding qqmlobjectcreator.cpp 765 0x659c9887 33 QQmlObjectCreator::setupBindings qqmlobjectcreator.cpp 724 0x659c94b5 34 QQmlObjectCreator::populateInstance qqmlobjectcreator.cpp 1316 0x659cc182 35 QQmlObjectCreator::createInstance qqmlobjectcreator.cpp 1158 0x659cb7f9 36 QQmlObjectCreator::setPropertyBinding qqmlobjectcreator.cpp 765 0x659c9887 37 QQmlObjectCreator::setupBindings qqmlobjectcreator.cpp 724 0x659c94b5 38 QQmlObjectCreator::populateInstance qqmlobjectcreator.cpp 1316 0x659cc182 39 QQmlObjectCreator::createInstance qqmlobjectcreator.cpp 1158 0x659cb7f9 40 QQmlObjectCreator::setPropertyBinding qqmlobjectcreator.cpp 765 0x659c9887 41 QQmlObjectCreator::setupBindings qqmlobjectcreator.cpp 724 0x659c94b5 42 QQmlObjectCreator::populateInstance qqmlobjectcreator.cpp 1316 0x659cc182 43 QQmlObjectCreator::createInstance qqmlobjectcreator.cpp 1158 0x659cb7f9 44 QQmlObjectCreator::create qqmlobjectcreator.cpp 219 0x659c6cc3 45 QQmlObjectCreator::createInstance qqmlobjectcreator.cpp 1075 0x659cb1c9 46 QQmlObjectCreator::create qqmlobjectcreator.cpp 219 0x659c6cc3 47 QQmlObjectCreator::createInstance qqmlobjectcreator.cpp 1075 0x659cb1c9 48 QQmlObjectCreator::create qqmlobjectcreator.cpp 219 0x659c6cc3 49 QQmlComponentPrivate::beginCreate qqmlcomponent.cpp 884 0x6592d7ff 50 QQmlComponent::beginCreate qqmlcomponent.cpp 834 0x6592d512 51 Hmi::Core::KeyboardAbstract::generateKeyboard KeyboardAbstract.cpp 474 0x10062ff3 52 Hmi::Core::KeyboardAbstract::handleKeysChanged KeyboardAbstract.cpp 302 0x100627df 53 Hmi::Core::KeyboardAbstract::qt_static_metacall KeyboardAbstract.moc.1.cpp 150 0x100aaba0 54 QMetaObject::activate qobject.cpp 3680 0x5a29b66c 55 QMetaObject::activate qobject.cpp 3546 0x5a29b081 56 Hmi::Core::KeyboardModel::keysChanged KeyboardModel.moc.1.cpp 285 0x100ac7ea 57 Hmi::Core::KeyboardModel::setLevel KeyboardModel.cpp 277 0x1006bcbb 58 Hmi::Core::KeyboardModel::qt_metacall KeyboardModel.moc.1.cpp 260 0x100ac70c 59 QMetaObject::metacall qmetaobject.cpp 309 0x5a2542a0 60 QQmlPropertyPrivate::write qqmlproperty.cpp 1449 0x659282a2 61 QQmlPropertyPrivate::writeValueProperty qqmlproperty.cpp 1246 0x659274ce 62 QQmlPropertyPrivate::writeValueProperty qqmlproperty.cpp 1212 0x65927390 63 QQmlPropertyPrivate::write qqmlproperty.cpp 1709 0x65929582 64 QQmlProperty::write qqmlproperty.cpp 1631 0x659293e9 65 QQmlBind::eval qqmlbind.cpp 307 0x65a19fa4 66 QQmlBind::setObject qqmlbind.cpp 209 0x65a19c36 67 QQmlBind::qt_metacall moc_qqmlbind_p.cpp 118 0x65a5a2a5 68 QMetaObject::metacall qmetaobject.cpp 309 0x5a2542a0 69 QQmlPropertyPrivate::write qqmlproperty.cpp 1317 0x659278f3 70 QQmlPropertyPrivate::writeValueProperty qqmlproperty.cpp 1246 0x659274ce 71 QQmlPropertyPrivate::writeBinding qqmlproperty.cpp 1572 0x6592904a 72 QQmlBinding::update qqmlbinding.cpp 266 0x659bb660 73 QQmlBinding::update qqmlbinding_p.h 105 0x6578906b 74 QQmlBinding::expressionChanged qqmlbinding.cpp 328 0x659bba3c 75 QQmlJavaScriptExpressionGuard_callback qqmljavascriptexpression.cpp 371 0x659b0c3e 76 QQmlNotifier::emitNotify qqmlnotifier.cpp 81 0x6598b0bc 77 QQmlData::signalEmitted qqmlengine.cpp 721 0x6590a5cc 78 QMetaObject::activate qobject.cpp 3567 0x5a29b13f 79 QMetaObject::activate qobject.cpp 3546 0x5a29b081 80 Hmi::Core::KeyboardAbstract::modelChanged KeyboardAbstract.moc.1.cpp 333 0x100ab2ca 81 Hmi::Core::KeyboardAbstract::setModel KeyboardAbstract.cpp 224 0x10062659 82 Hmi::Core::KeyboardAbstract::setGroupName KeyboardAbstract.cpp 261 0x1006271a 83 Hmi::Core::KeyboardAbstract::qt_metacall KeyboardAbstract.moc.1.cpp 284 0x100ab116 84 QQmlVMEMetaObject::metaCall qqmlvmemetaobject.cpp 981 0x65903fec 85 QAbstractDynamicMetaObject::metaCall qobject_p.h 428 0x59f6cd90 86 QMetaObject::metacall qmetaobject.cpp 306 0x5a254283 87 QQmlPropertyPrivate::writeBinding qqmlproperty.cpp 1500 0x6592893e 88 QQmlBinding::update qqmlbinding.cpp 266 0x659bb660 89 QQmlBinding::update qqmlbinding_p.h 105 0x6578906b 90 QQmlBinding::expressionChanged qqmlbinding.cpp 328 0x659bba3c 91 QQmlJavaScriptExpressionGuard_callback qqmljavascriptexpression.cpp 371 0x659b0c3e 92 QQmlNotifier::emitNotify qqmlnotifier.cpp 81 0x6598b0bc 93 QQmlNotifier::emitNotify qqmlnotifier.cpp 76 0x6598b054 94 QQmlNotifier::emitNotify qqmlnotifier.cpp 76 0x6598b054 95 QQmlNotifier::emitNotify qqmlnotifier.cpp 76 0x6598b054 96 QQmlNotifier::emitNotify qqmlnotifier.cpp 76 0x6598b054 97 QQmlNotifier::emitNotify qqmlnotifier.cpp 76 0x6598b054 98 QQmlNotifier::emitNotify qqmlnotifier.cpp 76 0x6598b054 99 QQmlNotifier::emitNotify qqmlnotifier.cpp 76 0x6598b054 100 QQmlNotifier::emitNotify qqmlnotifier.cpp 76 0x6598b054 101 QQmlNotifier::emitNotify qqmlnotifier.cpp 76 0x6598b054 102 QQmlNotifier::emitNotify qqmlnotifier.cpp 76 0x6598b054 103 QQmlNotifier::emitNotify qqmlnotifier.cpp 76 0x6598b054 104 QQmlNotifier::emitNotify qqmlnotifier.cpp 76 0x6598b054 105 QQmlNotifier::emitNotify qqmlnotifier.cpp 76 0x6598b054 106 QQmlNotifier::emitNotify qqmlnotifier.cpp 76 0x6598b054 107 QQmlNotifier::emitNotify qqmlnotifier.cpp 76 0x6598b054 108 QQmlNotifier::emitNotify qqmlnotifier.cpp 76 0x6598b054 109 QQmlNotifier::emitNotify qqmlnotifier.cpp 76 0x6598b054 110 QQmlNotifier::emitNotify qqmlnotifier.cpp 76 0x6598b054 111 QQmlNotifier::emitNotify qqmlnotifier.cpp 76 0x6598b054 112 QQmlNotifier::emitNotify qqmlnotifier.cpp 76 0x6598b054 113 QQmlNotifier::emitNotify qqmlnotifier.cpp 76 0x6598b054 114 QQmlNotifier::emitNotify qqmlnotifier.cpp 76 0x6598b054 115 QQmlData::signalEmitted qqmlengine.cpp 721 0x6590a5cc 116 QMetaObject::activate qobject.cpp 3567 0x5a29b13f 117 QQmlVMEMetaObject::activate qqmlvmemetaobject.cpp 1333 0x6590540c 118 QQmlVMEVariantQObjectPtr::objectDestroyed qqmlvmemetaobject.cpp 88 0x659075ef 119 QQmlData::destroyed qqmlengine.cpp 1659 0x6590c079 120 QQmlData::destroyed qqmlengine.cpp 633 0x6590a292 121 QObject::~QObject qobject.cpp 916 0x5a295631 122 QQuickItem::~QQuickItem qquickitem.cpp 2118 0xf437805 123 QQuickFocusScope::~QQuickFocusScope qquickfocusscope.cpp 69 0xf468be2 124 QQmlPrivate::QQmlElement<QQuickFocusScope>::~QQmlElement<QQuickFocusScope> qqmlprivate.h 106 0xf4a6cef 125 QQmlPrivate::QQmlElement<QQuickFocusScope>::`scalar deleting destructor' Qt5Quickd 0xf4967cf 126 QObjectPrivate::deleteChildren qobject.cpp 1935 0x5a296f29 127 QObject::~QObject qobject.cpp 1030 0x5a295a05 128 QQuickItem::~QQuickItem qquickitem.cpp 2118 0xf437805 129 QQmlPrivate::QQmlElement<QQuickItem>::~QQmlElement<QQuickItem> qqmlprivate.h 106 0xf4a6f5f 130 QQmlPrivate::QQmlElement<QQuickItem>::`scalar deleting destructor' Qt5Quickd 0xf49694f 131 qDeleteInEventHandler qobject.cpp 4342 0x5a29cf07 132 QObject::event qobject.cpp 1232 0x5a295d20 133 QQuickItem::event qquickitem.cpp 7112 0xf441e0b 134 QCoreApplicationPrivate::notify_helper qcoreapplication.cpp 1053 0x5a248cde 135 QCoreApplication::notify qcoreapplication.cpp 997 0x5a248a93 136 QGuiApplication::notify qguiapplication.cpp 1458 0x996d6a 137 QCoreApplication::notifyInternal qcoreapplication.cpp 935 0x5a2489e4 138 QCoreApplication::sendEvent qcoreapplication.h 237 0x5a24d379 139 QCoreApplicationPrivate::sendPostedEvents qcoreapplication.cpp 1539 0x5a249886 140 QCoreApplication::sendPostedEvents qcoreapplication.cpp 1397 0x5a249542 141 QWindowsGuiEventDispatcher::sendPostedEvents qwindowsguieventdispatcher.cpp 88 0x5746ce91 142 qt_internal_proc qeventdispatcher_win.cpp 423 0x5a2e1404 143 InternalCallWinProc USER32 0x772162fa 144 UserCallWinProcCheckWow USER32 0x77216d3a 145 DispatchMessageWorker USER32 0x772177c4 146 DispatchMessageW USER32 0x7721788a 147 QEventDispatcherWin32::processEvents qeventdispatcher_win.cpp 757 0x5a2e255b 148 QWindowsGuiEventDispatcher::processEvents qwindowsguieventdispatcher.cpp 80 0x5746cdbc 149 QEventLoop::processEvents qeventloop.cpp 137 0x5a2455fc 150 QEventLoop::exec qeventloop.cpp 212 0x5a245762 151 QCoreApplication::exec qcoreapplication.cpp 1188 0x5a248f42 152 QGuiApplication::exec qguiapplication.cpp 1437 0x996cb8 153 main main.cpp 135 0x4bc2e0 154 WinMain hmi_main 0x596702 155 __tmainCRTStartup crtexe.c 574 0x5952a8 156 WinMainCRTStartup crtexe.c 399 0x59500f 157 BaseThreadInitThunk kernel32 0x7594336a 158 __RtlUserThreadStart ntdll32 0x77c89f72 159 _RtlUserThreadStart ntdll32 0x77c89f45
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- Closed
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- Closed
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