[Marble-devel] Re: Problem with map creation

[Mülner, Helmut]

Hi,

I think I found the cause of the problem (but no solution):
It is a data race condition caused by the QFileSystemWatcher which results in a rebuild of the
m_mapThemeModel in MapThemeManager::updateMapThemeModel() which leads to undeterministic chaos, made worse by the existance of 3 (three!) MapThemeManagers, see:
C:\source\marble-trunk\marble\src\ControlView.cpp(80):    m_mapThemeManager = new MapThemeManager;
  C:\source\marble-trunk\marble\src\lib\MapViewWidget.cpp(162):        d->m_mapThemeManager = new MapThemeManager();
  C:\source\marble-trunk\marble\src\lib\MarbleModel.cpp(82):          m_mapThemeManager( new MapThemeManager( parent )),

In my local version I have removed the two duplicates (but broken the API), but this does not help, because the sequence of events depends on the behaviour of the QFileSystemWatcher and the speed and other characteristics of the filesystem.

Here the relevant stack traces:
 marblewidgetd.dll!Marble::MapThemeManager::updateMapThemeModel()  Line 297 C++
  marblewidgetd.dll!Marble::MapThemeManager::directoryChanged(const QString & path)  Line 323 C++
  marblewidgetd.dll!Marble::MapThemeManager::qt_metacall(QMetaObject::Call _c, int _id, void * * _a)  Line 82 + 0xf bytes C++
  QtCored4.dll!QMetaObject::metacall(QObject * object, QMetaObject::Call cl, int idx, void * * argv)  Line 238 C++
  QtCored4.dll!QMetaObject::activate(QObject * sender, const QMetaObject * m, int local_signal_index, void * * argv)  Line 3278 + 0x27 bytes C++
  QtCored4.dll!QFileSystemWatcher::directoryChanged(const QString & _t1)  Line 102 + 0x14 bytes C++
  QtCored4.dll!QFileSystemWatcherPrivate::_q_directoryChanged(const QString & path, bool removed)  Line 359 C++
  QtCored4.dll!QFileSystemWatcher::qt_metacall(QMetaObject::Call _c, int _id, void * * _a)  Line 86 C++
  QtCored4.dll!QMetaObject::metacall(QObject * object, QMetaObject::Call cl, int idx, void * * argv)  Line 238 C++
  QtCored4.dll!QMetaObject::activate(QObject * sender, const QMetaObject * m, int local_signal_index, void * * argv)  Line 3278 + 0x27 bytes C++
  QtCored4.dll!QFileSystemWatcherEngine::directoryChanged(const QString & _t1, bool _t2)  Line 95 + 0x14 bytes C++
  QtCored4.dll!QFileSystemWatcherEngine::qt_metacall(QMetaObject::Call _c, int _id, void * * _a)  Line 79 C++
  QtCored4.dll!QWindowsFileSystemWatcherEngine::qt_metacall(QMetaObject::Call _c, int _id, void * * _a)  Line 64 + 0x14 bytes C++
  QtCored4.dll!QMetaObject::metacall(QObject * object, QMetaObject::Call cl, int idx, void * * argv)  Line 238 C++
  QtCored4.dll!QMetaCallEvent::placeMetaCall(QObject * object)  Line 535 + 0x19 bytes C++
  QtCored4.dll!QObject::event(QEvent * e)  Line 1217 + 0x14 bytes C++
  QtGuid4.dll!QApplicationPrivate::notify_helper(QObject * receiver, QEvent * e)  Line 4462 + 0x11 bytes C++
  QtGuid4.dll!QApplication::notify(QObject * receiver, QEvent * e)  Line 3862 + 0x10 bytes C++
  QtCored4.dll!QCoreApplication::notifyInternal(QObject * receiver, QEvent * event)  Line 731 + 0x15 bytes C++
  QtCored4.dll!QCoreApplication::sendEvent(QObject * receiver, QEvent * event)  Line 215 + 0x39 bytes C++
  QtCored4.dll!QCoreApplicationPrivate::sendPostedEvents(QObject * receiver, int event_type, QThreadData * data)  Line 1372 + 0xd bytes C++
  QtCored4.dll!qt_internal_proc(HWND__ * hwnd, unsigned int message, unsigned int wp, long lp)  Line 497 + 0x10 bytes C++
  user32.dll!75a562fa()  
  [Frames below may be incorrect and/or missing, no symbols loaded for user32.dll] 
  user32.dll!75a56d3a()  
  user32.dll!75a56ce9()  
  user32.dll!75a577c4()  
  user32.dll!75a5788a()  
  QtCored4.dll!QEventDispatcherWin32::processEvents(QFlags<enum QEventLoop::ProcessEventsFlag> flags)  Line 813 C++
  QtGuid4.dll!QGuiEventDispatcherWin32::processEvents(QFlags<enum QEventLoop::ProcessEventsFlag> flags)  Line 1170 + 0x15 bytes C++
  QtCored4.dll!QEventLoop::processEvents(QFlags<enum QEventLoop::ProcessEventsFlag> flags)  Line 150 C++
  QtCored4.dll!QEventLoop::exec(QFlags<enum QEventLoop::ProcessEventsFlag> flags)  Line 201 + 0x2d bytes C++
  QtGuid4.dll!QDialog::exec()  Line 553 C++
  marblewidgetd.dll!Marble::MarbleMap::setMapThemeId(const QString & mapThemeId)  Line 830 + 0x15 bytes C++
  marblewidgetd.dll!Marble::MarbleWidget::setMapThemeId(const QString & mapThemeId)  Line 847 C++
  marblewidgetd.dll!Marble::MarbleWidget::qt_metacall(QMetaObject::Call _c, int _id, void * * _a)  Line 302 + 0xf bytes C++
  QtCored4.dll!QMetaObject::metacall(QObject * object, QMetaObject::Call cl, int idx, void * * argv)  Line 238 C++
  QtCored4.dll!QMetaObject::activate(QObject * sender, const QMetaObject * m, int local_signal_index, void * * argv)  Line 3278 + 0x27 bytes C++
  marblewidgetd.dll!Marble::MapViewWidget::selectMapTheme(const QString & _t1)  Line 109 + 0x17 bytes C++
  marblewidgetd.dll!Marble::MapViewWidget::qt_metacall(QMetaObject::Call _c, int _id, void * * _a)  Line 89 + 0xf bytes C++
  QtCored4.dll!QMetaObject::metacall(QObject * object, QMetaObject::Call cl, int idx, void * * argv)  Line 238 C++
  QtCored4.dll!QMetaObject::activate(QObject * sender, const QMetaObject * m, int local_signal_index, void * * argv)  Line 3278 + 0x27 bytes C++
  marblewidgetd.dll!Marble::MarbleThemeSelectView::selectMapTheme(const QString & _t1)  Line 108 + 0x17 bytes C++
  marblewidgetd.dll!Marble::MarbleThemeSelectView::selectedMapTheme(QModelIndex index)  Line 159 C++
  marblewidgetd.dll!Marble::MarbleThemeSelectView::qt_metacall(QMetaObject::Call _c, int _id, void * * _a)  Line 91 + 0x29 bytes C++
 ...

 marblewidgetd.dll!Marble::MapViewWidget::selectTheme(const QString & theme)  Line 201 C++ theme = earth/plain/plain.dgml
  marblewidgetd.dll!Marble::MapViewWidget::updateMapThemeView()  Line 176 C++
  marblewidgetd.dll!Marble::MapViewWidget::qt_metacall(QMetaObject::Call _c, int _id, void * * _a)  Line 96 + 0x8 bytes C++
  QtCored4.dll!QMetaObject::metacall(QObject * object, QMetaObject::Call cl, int idx, void * * argv)  Line 238 C++
  QtCored4.dll!QMetaObject::activate(QObject * sender, const QMetaObject * m, int local_signal_index, void * * argv)  Line 3278 + 0x27 bytes C++
  QtCored4.dll!QAbstractItemModel::rowsInserted(const QModelIndex & _t1, int _t2, int _t3)  Line 181 + 0x14 bytes C++
  QtCored4.dll!QAbstractItemModel::endInsertRows()  Line 2413 C++
  QtGuid4.dll!QStandardItemModelPrivate::rowsInserted(QStandardItem * parent, int row, int count)  Line 559 C++
  QtGuid4.dll!QStandardItemPrivate::insertRows(int row, int count, const QList<QStandardItem *> & items)  Line 434 C++
  QtGuid4.dll!QStandardItem::insertRow(int row, const QList<QStandardItem *> & items)  Line 1458 C++
  QtGuid4.dll!QStandardItem::appendRow(const QList<QStandardItem *> & aitems)  Line 302 + 0x1c bytes C++
  QtGuid4.dll!QStandardItemModel::appendRow(const QList<QStandardItem *> & items)  Line 2464 C++
  marblewidgetd.dll!Marble::MapThemeManager::updateMapThemeModel()  Line 308 + 0x14 bytes C++
  marblewidgetd.dll!Marble::MapThemeManager::directoryChanged(const QString & path)  Line 323 C++
  marblewidgetd.dll!Marble::MapThemeManager::qt_metacall(QMetaObject::Call _c, int _id, void * * _a)  Line 82 + 0xf bytes C++
  QtCored4.dll!QMetaObject::metacall(QObject * object, QMetaObject::Call cl, int idx, void * * argv)  Line 238 C++
  QtCored4.dll!QMetaObject::activate(QObject * sender, const QMetaObject * m, int local_signal_index, void * * argv)  Line 3278 + 0x27 bytes C++
  QtCored4.dll!QFileSystemWatcher::directoryChanged(const QString & _t1)  Line 102 + 0x14 bytes C++
  QtCored4.dll!QFileSystemWatcherPrivate::_q_directoryChanged(const QString & path, bool removed)  Line 359 C++
  QtCored4.dll!QFileSystemWatcher::qt_metacall(QMetaObject::Call _c, int _id, void * * _a)  Line 86 C++
  QtCored4.dll!QMetaObject::metacall(QObject * object, QMetaObject::Call cl, int idx, void * * argv)  Line 238 C++
  QtCored4.dll!QMetaObject::activate(QObject * sender, const QMetaObject * m, int local_signal_index, void * * argv)  Line 3278 + 0x27 bytes C++
  QtCored4.dll!QFileSystemWatcherEngine::directoryChanged(const QString & _t1, bool _t2)  Line 95 + 0x14 bytes C++
  QtCored4.dll!QFileSystemWatcherEngine::qt_metacall(QMetaObject::Call _c, int _id, void * * _a)  Line 79 C++
  QtCored4.dll!QWindowsFileSystemWatcherEngine::qt_metacall(QMetaObject::Call _c, int _id, void * * _a)  Line 64 + 0x14 bytes C++
  QtCored4.dll!QMetaObject::metacall(QObject * object, QMetaObject::Call cl, int idx, void * * argv)  Line 238 C++
  QtCored4.dll!QMetaCallEvent::placeMetaCall(QObject * object)  Line 535 + 0x19 bytes C++
  QtCored4.dll!QObject::event(QEvent * e)  Line 1217 + 0x14 bytes C++
  QtGuid4.dll!QApplicationPrivate::notify_helper(QObject * receiver, QEvent * e)  Line 4462 + 0x11 bytes C++
  QtGuid4.dll!QApplication::notify(QObject * receiver, QEvent * e)  Line 3862 + 0x10 bytes C++
  QtCored4.dll!QCoreApplication::notifyInternal(QObject * receiver, QEvent * event)  Line 731 + 0x15 bytes C++
  QtCored4.dll!QCoreApplication::sendEvent(QObject * receiver, QEvent * event)  Line 215 + 0x39 bytes C++
  QtCored4.dll!QCoreApplicationPrivate::sendPostedEvents(QObject * receiver, int event_type, QThreadData * data)  Line 1372 + 0xd bytes C++
  QtCored4.dll!qt_internal_proc(HWND__ * hwnd, unsigned int message, unsigned int wp, long lp)  Line 497 + 0x10 bytes C++
  user32.dll!75a562fa()  
  [Frames below may be incorrect and/or missing, no symbols loaded for user32.dll] 
  user32.dll!75a56d3a()  
  user32.dll!75a56ce9()  
  user32.dll!75a577c4()  
  user32.dll!75a5788a()  
  QtCored4.dll!QEventDispatcherWin32::processEvents(QFlags<enum QEventLoop::ProcessEventsFlag> flags)  Line 813 C++
  QtGuid4.dll!QGuiEventDispatcherWin32::processEvents(QFlags<enum QEventLoop::ProcessEventsFlag> flags)  Line 1170 + 0x15 bytes C++
  QtCored4.dll!QEventLoop::processEvents(QFlags<enum QEventLoop::ProcessEventsFlag> flags)  Line 150 C++
  QtCored4.dll!QEventLoop::exec(QFlags<enum QEventLoop::ProcessEventsFlag> flags)  Line 201 + 0x2d bytes C++
  QtGuid4.dll!QDialog::exec()  Line 553 C++
  marblewidgetd.dll!Marble::MarbleMap::setMapThemeId(const QString & mapThemeId)  Line 830 + 0x15 bytes C++
  marblewidgetd.dll!Marble::MarbleWidget::setMapThemeId(const QString & mapThemeId)  Line 847 C++
  marblewidgetd.dll!Marble::MarbleWidget::qt_metacall(QMetaObject::Call _c, int _id, void * * _a)  Line 302 + 0xf bytes C++
  QtCored4.dll!QMetaObject::metacall(QObject * object, QMetaObject::Call cl, int idx, void * * argv)  Line 238 C++
  QtCored4.dll!QMetaObject::activate(QObject * sender, const QMetaObject * m, int local_signal_index, void * * argv)  Line 3278 + 0x27 bytes C++
  marblewidgetd.dll!Marble::MapViewWidget::selectMapTheme(const QString & _t1)  Line 109 + 0x17 bytes C++
  marblewidgetd.dll!Marble::MapViewWidget::qt_metacall(QMetaObject::Call _c, int _id, void * * _a)  Line 89 + 0xf bytes C++
  QtCored4.dll!QMetaObject::metacall(QObject * object, QMetaObject::Call cl, int idx, void * * argv)  Line 238 C++
  QtCored4.dll!QMetaObject::activate(QObject * sender, const QMetaObject * m, int local_signal_index, void * * argv)  Line 3278 + 0x27 bytes C++
  marblewidgetd.dll!Marble::MarbleThemeSelectView::selectMapTheme(const QString & _t1)  Line 108 + 0x17 bytes C++
  marblewidgetd.dll!Marble::MarbleThemeSelectView::selectedMapTheme(QModelIndex index)  Line 159 C++
...

Best regards,
Helmut Mülner