Lockdown on session switch

Thread 28 (Thread 0x7f69769fe700 (LWP 255642)):
#0  0x00007f6a222b300b in __lll_lock_wait_private () from /usr/lib/libc.so.6
#1  0x00007f6a222b545a in _int_free () from /usr/lib/libc.so.6
#2  0x00007f6a22a0bc6a in ?? () from /usr/lib/libQt5Core.so.5  
#3  0x00007f6a22a06bc1 in ?? () from /usr/lib/libQt5Core.so.5
#4  0x00007f6a22a07950 in QCoreApplication::postEvent(QObject*, QEvent*, int) () from /usr/lib/libQt5Core.so.5
#5  0x00007f6a22a30cc0 in ?? () from /usr/lib/libQt5Core.so.5
#6  0x00007f6a22a3b8a5 in ?? () from /usr/lib/libQt5Core.so.5
#7  0x00007f6a1098fa05 in CppTools::CppModelManager::documentUpdated (this=this@entry=0x55e33f20b038, _t1=...) at /sda/home/christian/dev/qtcreator/super-4.13/default/CppTools.52d82d93/qt.headers/moc_cppmodelmanager.cpp:298
#8  0x00007f6a1093aadf in CppTools::CppModelManager::emitDocumentUpdated (this=0x55e33f20b038, doc=...) at /usr/include/c++/10.1.0/bits/atomic_base.h:325                                                                                                     
#9  0x00007f6a1093abb2 in operator() (doc=..., __closure=0x7f6840602378) at /usr/include/c++/10.1.0/bits/atomic_base.h:325     
#10 std::__invoke_impl<void, CppTools::CppModelManager::createSourceProcessor()::<lambda(const Ptr&)>&, const QSharedPointer<CPlusPlus::Document>&> (__f=...) at /usr/include/c++/10.1.0/bits/invoke.h:60                                                     
#11 std::__invoke_r<void, CppTools::CppModelManager::createSourceProcessor()::<lambda(const Ptr&)>&, const QSharedPointer<CPlusPlus::Document>&> (__fn=...) at /usr/include/c++/10.1.0/bits/invoke.h:153                                                      
#12 std::_Function_handler<void(const QSharedPointer<CPlusPlus::Document>&), CppTools::CppModelManager::createSourceProcessor()::<lambda(const Ptr&)> >::_M_invoke(const std::_Any_data &, const QSharedPointer<CPlusPlus::Document> &) (__functor=..., __args#0=...) at /usr/include/c++/10.1.0/bits/std_function.h:291
#13 0x00007f6a10960c8a in std::function<void (QSharedPointer<CPlusPlus::Document> const&)>::operator()(QSharedPointer<CPlusPlus::Document> const&) const (__args#0=..., this=0x7f6840602378) at /usr/include/c++/10.1.0/bits/std_function.h:617               
#14 CppTools::Internal::CppSourceProcessor::sourceNeeded (this=0x7f6840602320, line=<optimized out>, fileName=..., type=<optimized out>, initialIncludes=...) at /sda/home/christian/dev/qtcreator/super-4.13/src/qtcreator/src/plugins/cpptools/cppsourceprocessor.cpp:501                              
#15 0x00007f6a108c4ee1 in (anonymous namespace)::index (params=..., superFuture=..., indexingFuture=...) at /usr/include/qt/QtCore/qlist.h:160                                                                                                                
#16 (anonymous namespace)::parse (indexingFuture=..., superFuture=..., params=...) at /sda/home/christian/dev/qtcreator/super-4.13/src/qtcreator/src/plugins/cpptools/builtinindexingsupport.cpp:259                                                          
#17 0x00007f6a108c2201 in Utils::Internal::runAsyncQFutureInterfaceDispatch<void, void (*)(QFutureInterface<void>&, QFutureInterface<void> const&, (anonymous namespace)::ParseParams), QFutureInterface<void>, (anonymous namespace)::ParseParams> (function=@0x55e3491395a0: 0x7f6a108c4930 <(anonymous namespace)::parse(QFutureInterface<void>&, QFutureInterface<void> const&, (anonymous namespace)::ParseParams)>, function=@0x55e3491395a0: 0x7f6a108c4930 <(anonymous namespace)::parse(QFutureInterface<void>&, QFutureInterface<void> const&, (anonymous namespace)::ParseParams)>, futureInterface=...) at /usr/include/qt/QtCore/qhash.h:253  
#18 Utils::Internal::runAsyncMemberDispatch<void, void (*)(QFutureInterface<void>&, QFutureInterface<void> const&, (anonymous namespace)::ParseParams), QFutureInterface<void>, (anonymous namespace)::ParseParams> (function=@0x55e3491395a0: 0x7f6a108c4930 <(anonymous namespace)::parse(QFutureInterface<void>&, QFutureInterface<void> const&, (anonymous namespace)::ParseParams)>, futureInterface=...) at /sda/home/christian/dev/qtcreator/super-4.13/src/qtcreator/src/libs/utils/runextensions.h:274             
#19 Utils::Internal::runAsyncImpl<void, void (*)(QFutureInterface<void>&, QFutureInterface<void> const&, (anonymous namespace)::ParseParams), QFutureInterface<void>, (anonymous namespace)::ParseParams> (function=@0x55e3491395a0: 0x7f6a108c4930 <(anonymous namespace)::parse(QFutureInterface<void>&, QFutureInterface<void> const&, (anonymous namespace)::ParseParams)>, futureInterface=...) at /sda/home/christian/dev/qtcreator/super-4.13/src/qtcreator/src/libs/utils/runextensions.h:303                       
#20 Utils::Internal::AsyncJob<void, void (&)(QFutureInterface<void>&, QFutureInterface<void> const&, (anonymous namespace)::ParseParams), QFutureInterface<void> const&, (anonymous namespace)::ParseParams&>::runHelper<0, 1, 2> (this=0x55e349139560) at /sda/home/christian/dev/qtcreator/super-4.13/src/qtcreator/src/libs/utils/runextensions.h:372                                     
#21 Utils::Internal::AsyncJob<void, void (&)(QFutureInterface<void>&, QFutureInterface<void> const&, (anonymous namespace)::ParseParams), QFutureInterface<void> const&, (anonymous namespace)::ParseParams&>::run (this=0x55e349139560) at /sda/home/christian/dev/qtcreator/super-4.13/src/qtcreator/src/libs/utils/runextensions.h:352                                                    
#22 0x00007f6a22823de2 in ?? () from /usr/lib/libQt5Core.so.5
#23 0x00007f6a2281fe0f in ?? () from /usr/lib/libQt5Core.so.5
#24 0x00007f6a22739422 in start_thread () from /usr/lib/libpthread.so.0                                                        
#25 0x00007f6a2232cbf3 in clone () from /usr/lib/libc.so.6

Thread 1 (Thread 0x7f6a1edc8800 (LWP 3092773)):
#0  0x00007f6a222b300b in __lll_lock_wait_private () from /usr/lib/libc.so.6
#1  0x00007f6a222b8209 in __malloc_fork_lock_parent () from /usr/lib/libc.so.6
#2  0x00007f6a222f9fda in fork () from /usr/lib/libc.so.6
#3  0x000055e33d7a6f72 in signalHandler (signal=11) at /sda/home/christian/dev/qtcreator/super-4.13/src/qtcreator/src/tools/qtcreatorcrashhandler/crashhandlersetup.cpp:75
#4  <signal handler called>
#5  0x00007f6a222b7248 in _int_malloc () from /usr/lib/libc.so.6
#6  0x00007f6a222b85a9 in malloc () from /usr/lib/libc.so.6
#7  0x00007f6a225f652a in operator new (sz=sz@entry=24) at /build/gcc/src/gcc/libstdc++-v3/libsupc++/new_op.cc:50
#8  0x00007f6a112bb4c2 in QList<Core::Internal::OpenDocumentsFilter::Entry>::node_construct (this=0x55e33e92aa38, t=..., n=0x55e341bf4ed8) at /usr/include/qt/QtCore/qlist.h:463
#9  QList<Core::Internal::OpenDocumentsFilter::Entry>::append (this=this@entry=0x55e33e92aa38, t=...) at /usr/include/qt/QtCore/qlist.h:634
#10 0x00007f6a112ba6c6 in Core::Internal::OpenDocumentsFilter::refreshInternally (this=0x55e33e92a9f8) at /sda/home/christian/dev/qtcreator/super-4.13/src/qtcreator/src/plugins/coreplugin/locator/opendocumentsfilter.cpp:103
#11 0x00007f6a22a3b906 in ?? () from /usr/lib/libQt5Core.so.5
#12 0x00007f6a2299deaf in QAbstractItemModel::rowsInserted(QModelIndex const&, int, int, QAbstractItemModel::QPrivateSignal) () from /usr/lib/libQt5Core.so.5
#13 0x00007f6a229a6731 in QAbstractItemModel::endInsertRows() () from /usr/lib/libQt5Core.so.5
#14 0x00007f6a112f4be7 in Core::Internal::DocumentModelPrivate::addEntry (this=0x55e33e9303e0, entry=<optimized out>) at /sda/home/christian/dev/qtcreator/super-4.13/src/qtcreator/src/plugins/coreplugin/editormanager/documentmodel.cpp:141
#15 0x00007f6a112f5ccf in Core::Internal::DocumentModelPrivate::addSuspendedDocument (fileName=..., displayName=..., id=...) at /sda/home/christian/dev/qtcreator/super-4.13/src/qtcreator/src/plugins/coreplugin/editormanager/documentmodel.cpp:441
#16 0x00007f6a1130a5e8 in Core::EditorManager::restoreState (state=...) at /sda/home/christian/dev/qtcreator/super-4.13/src/qtcreator/src/plugins/coreplugin/editormanager/editormanager.cpp:3386
#17 0x00007f6a10c9ea03 in ProjectExplorer::SessionManagerPrivate::restoreEditors (this=0x55e33f0c6f10, reader=...) at /sda/home/christian/dev/qtcreator/super-4.13/src/qtcreator/src/plugins/projectexplorer/session.cpp:935
#18 0x00007f6a10ca6144 in ProjectExplorer::SessionManager::loadSession (session=..., initial=initial@entry=false) at /sda/home/christian/dev/qtcreator/super-4.13/src/qtcreator/src/plugins/projectexplorer/session.cpp:1090
#19 0x00007f6a10c218a8 in ProjectExplorer::ProjectExplorerPluginPrivate::setSession (this=<optimized out>, action=<optimized out>) at /sda/home/christian/dev/qtcreator/super-4.13/src/qtcreator/src/plugins/projectexplorer/projectexplorer.cpp:3852
#20 0x00007f6a22a3b906 in ?? () from /usr/lib/libQt5Core.so.5
#21 0x00007f6a2365abe0 in QActionGroup::triggered(QAction*) () from /usr/lib/libQt5Widgets.so.5
#22 0x00007f6a22a3b940 in ?? () from /usr/lib/libQt5Core.so.5
#23 0x00007f6a23656f23 in QAction::triggered(bool) () from /usr/lib/libQt5Widgets.so.5
#24 0x00007f6a23659805 in QAction::activate(QAction::ActionEvent) () from /usr/lib/libQt5Widgets.so.5
#25 0x00007f6a237daf1b in ?? () from /usr/lib/libQt5Widgets.so.5
#26 0x00007f6a237e2552 in ?? () from /usr/lib/libQt5Widgets.so.5
#27 0x00007f6a2369ec7e in QWidget::event(QEvent*) () from /usr/lib/libQt5Widgets.so.5
#28 0x00007f6a2365d702 in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /usr/lib/libQt5Widgets.so.5
#29 0x00007f6a23664977 in QApplication::notify(QObject*, QEvent*) () from /usr/lib/libQt5Widgets.so.5
#30 0x00007f6a22a0469a in QCoreApplication::notifyInternal2(QObject*, QEvent*) () from /usr/lib/libQt5Core.so.5
#31 0x00007f6a2366385e in QApplicationPrivate::sendMouseEvent(QWidget*, QMouseEvent*, QWidget*, QWidget*, QWidget**, QPointer<QWidget>&, bool, bool) () from /usr/lib/libQt5Widgets.so.5
#32 0x00007f6a236b792f in ?? () from /usr/lib/libQt5Widgets.so.5
#33 0x00007f6a236ba78f in ?? () from /usr/lib/libQt5Widgets.so.5
#34 0x00007f6a2365d702 in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /usr/lib/libQt5Widgets.so.5