Details
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Suggestion
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Resolution: Unresolved
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P2: Important
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None
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5.9.5, 5.14.1, 5.14.2
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None
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All
Description
When a progress dialog that is set to window modal is updated too fast from a thread by sending a signal that is connected (not using Qt::DirectConnection) to QProgressDialog::setValue, it produces a stack overflow error. This example shows a thread with two different calculations one that emits an update value every few milliseconds and one that emits as fast as it can. In both cases, the signals from the thread are connected without using Qt::DirectConnection to the QProgressDialog::setValue slot of the QProgressDialog in the main application thread. The second one produces the stack overflow error.
Here is an example stack call from Ubuntu:
# #0 0x00007ffff76fa330 in QProgressDialog::setValue(int) () at /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5 # #1 0x00007ffff60a3dec in QtPrivate::FunctorCall<QtPrivate::IndexesList<0>, QtPrivate::List<int>, void, void (QProgressDialog:: )(int)>::call(void (QProgressDialog:: )(int), QProgressDialog*, void*) () at /home/apalomer/programming_workspace/progress_bar_example/build/libthreadedworker.so # #2 0x00007ffff60a3ba4 in void QtPrivate::FunctionPointer<void (QProgressDialog:: )(int)>::call<QtPrivate::List<int>, void>(void (QProgressDialog:: )(int), QProgressDialog, void*) () at /home/apalomer/programming_workspace/progress_bar_example/build/libthreadedworker.so # #3 0x00007ffff60a3759 in QtPrivate::QSlotObject<void (QProgressDialog:: )(int), QtPrivate::List<int>, void>::impl(int, QtPrivate::QSlotObjectBase*, QObject*, void*, bool) () at /home/apalomer/programming_workspace/progress_bar_example/build/libthreadedworker.so # #4 0x00007ffff6ef30c2 in QObject::event(QEvent*) (this=0x555555b74610, e=<optimized out>) at kernel/qobject.cpp:1247 # #5 0x00007ffff751775b in QWidget::event(QEvent*) () at /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5 # #6 0x00007ffff74d883c in QApplicationPrivate::notify_helper(QObject*, QEvent*) () at /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5 # #7 0x00007ffff74e0104 in QApplication::notify(QObject*, QEvent*) () at /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5 # #8 0x00007ffff6ec38d8 in QCoreApplication::notifyInternal2(QObject*, QEvent*) (receiver=0x555555b74610, event=event@entry=0x7fffc80037a0) at kernel/qcoreapplication.cpp:1024 # #9 0x00007ffff6ec604d in QCoreApplication::sendEvent(QObject*, QEvent*) (event=0x7fffc80037a0, receiver=<optimized out>) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:233 # #10 0x00007ffff6ec604d in QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) (receiver=receiver@entry=0x0, event_type=event_type@entry=0, data=0x55555576fef0) at kernel/qcoreapplication.cpp:1699 # #11 0x00007ffff6ec65d8 in QCoreApplication::sendPostedEvents(QObject*, int) (receiver=receiver@entry=0x0, event_type=event_type@entry=0) at kernel/qcoreapplication.cpp:1553 # #12 0x00007ffff6f1d263 in postEventSourceDispatch(GSource*, GSourceFunc, gpointer) (s=0x5555558952a0) at kernel/qeventdispatcher_glib.cpp:276 # #13 0x00007ffff4221417 in g_main_context_dispatch () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0 # #14 0x00007ffff4221650 in () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0 # #15 0x00007ffff42216dc in g_main_context_iteration () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0 # #16 0x00007ffff6f1c88f in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x5555558d2b80, flags=...) at kernel/qeventdispatcher_glib.cpp:423 # #17 0x00007ffff76fa4c7 in QProgressDialog::setValue(int) () at /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5 # #18 0x00007ffff60a3dec in QtPrivate::FunctorCall<QtPrivate::IndexesList<0>, QtPrivate::List<int>, void, void (QProgressDialog:: )(int)>::call(void (QProgressDialog:: )(int), QProgressDialog*, void*) () at /home/apalomer/programming_workspace/progress_bar_example/build/libthreadedworker.so # #19 0x00007ffff60a3ba4 in void QtPrivate::FunctionPointer<void (QProgressDialog:: )(int)>::call<QtPrivate::List<int>, void>(void (QProgressDialog:: )(int), QProgressDialog, void*) () at /home/apalomer/programming_workspace/progress_bar_example/build/libthreadedworker.so # #20 0x00007ffff60a3759 in QtPrivate::QSlotObject<void (QProgressDialog:: )(int), QtPrivate::List<int>, void>::impl(int, QtPrivate::QSlotObjectBase*, QObject*, void*, bool) () at /home/apalomer/programming_workspace/progress_bar_example/build/libthreadedworker.so # #21 0x00007ffff6ef30c2 in QObject::event(QEvent*) (this=0x555555b74610, e=<optimized out>) at kernel/qobject.cpp:1247 # #22 0x00007ffff751775b in QWidget::event(QEvent*) () at /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5 # #23 0x00007ffff74d883c in QApplicationPrivate::notify_helper(QObject*, QEvent*) () at /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5 # #24 0x00007ffff74e0104 in QApplication::notify(QObject*, QEvent*) () at /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5 # #25 0x00007ffff6ec38d8 in QCoreApplication::notifyInternal2(QObject*, QEvent*) (receiver=0x555555b74610, event=event@entry=0x7fffc8002ef0) at kernel/qcoreapplication.cpp:1024 # #26 0x00007ffff6ec604d in QCoreApplication::sendEvent(QObject*, QEvent*) (event=0x7fffc8002ef0, receiver=<optimized out>) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:233 # #27 0x00007ffff6ec604d in QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) (receiver=receiver@entry=0x0, event_type=event_type@entry=0, data=0x55555576fef0) at kernel/qcoreapplication.cpp:1699 # #28 0x00007ffff6ec65d8 in QCoreApplication::sendPostedEvents(QObject*, int) (receiver=receiver@entry=0x0, event_type=event_type@entry=0) at kernel/qcoreapplication.cpp:1553 # #29 0x00007ffff6f1d263 in postEventSourceDispatch(GSource*, GSourceFunc, gpointer) (s=0x5555558952a0) at kernel/qeventdispatcher_glib.cpp:276 # #30 0x00007ffff4221417 in g_main_context_dispatch () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0 # #31 0x00007ffff4221650 in () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0 # #32 0x00007ffff42216dc in g_main_context_iteration () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0 # #33 0x00007ffff6f1c88f in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) (this=0x5555558d2b80, flags=...) at kernel/qeventdispatcher_glib.cpp:423 # #34 0x00007ffff6ec190a in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) (this=this@entry=0x7fffffffcfb0, flags=..., flags@entry=...) at kernel/qeventloop.cpp:212 # #35 0x00007ffff6eca9b4 in QCoreApplication::exec() () at kernel/qcoreapplication.cpp:1297 # #36 0x0000555555554cb4 in main ()
And here one from windows
# Qt5Widgets.dll!QProgressDialog::setValue(int progress) Line 653 C++ # [Inline Frame] Qt5Core.dll!QtPrivate::QSlotObjectBase::call(QObject *) Line 398 C++ # Qt5Core.dll!QMetaCallEvent::placeMetaCall(QObject * object) Line 626 C++ # Qt5Core.dll!QObject::event(QEvent * e) Line 1339 C++ # Qt5Widgets.dll!QWidget::event(QEvent * event) Line 9094 C++ # Qt5Widgets.dll!QApplicationPrivate::notify_helper(QObject * receiver, QEvent * e) Line 3687 C++ # Qt5Widgets.dll!QApplication::notify(QObject * receiver, QEvent * e) Line 3639 C++ # Qt5Core.dll!QCoreApplication::notifyInternal2(QObject * receiver, QEvent * event) Line 1075 C++ # [Inline Frame] Qt5Core.dll!QCoreApplication::sendEvent(QObject *) Line 1470 C++ # Qt5Core.dll!QCoreApplicationPrivate::sendPostedEvents(QObject * receiver, int event_type, QThreadData * data) Line 1815 C++ # qwindows.dll!QWindowsGuiEventDispatcher::sendPostedEvents() Line 82 C++ # Qt5Core.dll!QEventDispatcherWin32::processEvents(QFlags<enum QEventLoop::ProcessEventsFlag> flags) Line 525 C++ # qwindows.dll!QWindowsGuiEventDispatcher::processEvents(QFlags<enum QEventLoop::ProcessEventsFlag> flags) Line 75 C++ # Qt5Widgets.dll!QProgressDialog::setValue(int progress) Line 663 C++ # [Inline Frame] Qt5Core.dll!QtPrivate::QSlotObjectBase::call(QObject *) Line 398 C++ # Qt5Core.dll!QMetaCallEvent::placeMetaCall(QObject * object) Line 626 C++ # Qt5Core.dll!QObject::event(QEvent * e) Line 1339 C++ # Qt5Widgets.dll!QWidget::event(QEvent * event) Line 9094 C++ # Qt5Widgets.dll!QApplicationPrivate::notify_helper(QObject * receiver, QEvent * e) Line 3687 C++ # Qt5Widgets.dll!QApplication::notify(QObject * receiver, QEvent * e) Line 3639 C++ # Qt5Core.dll!QCoreApplication::notifyInternal2(QObject * receiver, QEvent * event) Line 1075 C++ # [Inline Frame] Qt5Core.dll!QCoreApplication::sendEvent(QObject *) Line 1470 C++ # Qt5Core.dll!QCoreApplicationPrivate::sendPostedEvents(QObject * receiver, int event_type, QThreadData * data) Line 1815 C++ # qwindows.dll!QWindowsGuiEventDispatcher::sendPostedEvents() Line 82 C++ # Qt5Core.dll!QEventDispatcherWin32::processEvents(QFlags<enum QEventLoop::ProcessEventsFlag> flags) Line 525 C++ # qwindows.dll!QWindowsGuiEventDispatcher::processEvents(QFlags<enum QEventLoop::ProcessEventsFlag> flags) Line 75 C++ # Qt5Widgets.dll!QProgressDialog::setValue(int progress) Line 663 C++ # [Inline Frame] Qt5Core.dll!QtPrivate::QSlotObjectBase::call(QObject *) Line 398 C++ # Qt5Core.dll!QMetaCallEvent::placeMetaCall(QObject * object) Line 626 C++ # Qt5Core.dll!QObject::event(QEvent * e) Line 1339 C++ # Qt5Widgets.dll!QWidget::event(QEvent * event) Line 9094 C++ # Qt5Widgets.dll!QApplicationPrivate::notify_helper(QObject * receiver, QEvent * e) Line 3687 C++ # Qt5Widgets.dll!QApplication::notify(QObject * receiver, QEvent * e) Line 3639 C++ # Qt5Core.dll!QCoreApplication::notifyInternal2(QObject * receiver, QEvent * event) Line 1075 C++ # [Inline Frame] Qt5Core.dll!QCoreApplication::sendEvent(QObject *) Line 1470 C++ # Qt5Core.dll!QCoreApplicationPrivate::sendPostedEvents(QObject * receiver, int event_type, QThreadData * data) Line 1815 C++ # qwindows.dll!QWindowsGuiEventDispatcher::sendPostedEvents() Line 82 C++ # Qt5Core.dll!QEventDispatcherWin32::processEvents(QFlags<enum QEventLoop::ProcessEventsFlag> flags) Line 525 C++ # qwindows.dll!QWindowsGuiEventDispatcher::processEvents(QFlags<enum QEventLoop::ProcessEventsFlag> flags) Line 75 C++ # Qt5Widgets.dll!QProgressDialog::setValue(int progress) Line 663 C++ # [Inline Frame] Qt5Core.dll!QtPrivate::QSlotObjectBase::call(QObject *) Line 398 C++ # Qt5Core.dll!QMetaCallEvent::placeMetaCall(QObject * object) Line 626 C++ # Qt5Core.dll!QObject::event(QEvent * e) Line 1339 C++ # Qt5Widgets.dll!QWidget::event(QEvent * event) Line 9094 C++ # Qt5Widgets.dll!QApplicationPrivate::notify_helper(QObject * receiver, QEvent * e) Line 3687 C++ # Qt5Widgets.dll!QApplication::notify(QObject * receiver, QEvent * e) Line 3639 C++ # Qt5Core.dll!QCoreApplication::notifyInternal2(QObject * receiver, QEvent * event) Line 1075 C++ # [Inline Frame] Qt5Core.dll!QCoreApplication::sendEvent(QObject *) Line 1470 C++ # Qt5Core.dll!QCoreApplicationPrivate::sendPostedEvents(QObject * receiver, int event_type, QThreadData * data) Line 1815 C++ # qwindows.dll!QWindowsGuiEventDispatcher::sendPostedEvents() Line 82 C++ # Qt5Core.dll!QEventDispatcherWin32::processEvents(QFlags<enum QEventLoop::ProcessEventsFlag> flags) Line 525 C++ # qwindows.dll!QWindowsGuiEventDispatcher::processEvents(QFlags<enum QEventLoop::ProcessEventsFlag> flags) Line 75 C++ # Qt5Widgets.dll!QProgressDialog::setValue(int progress) Line 663 C++ # [Inline Frame] Qt5Core.dll!QtPrivate::QSlotObjectBase::call(QObject *) Line 398 C++ # Qt5Core.dll!QMetaCallEvent::placeMetaCall(QObject * object) Line 626 C++ # Qt5Core.dll!QObject::event(QEvent * e) Line 1339 C++ # Qt5Widgets.dll!QWidget::event(QEvent * event) Line 9094 C++ # Qt5Widgets.dll!QApplicationPrivate::notify_helper(QObject * receiver, QEvent * e) Line 3687 C++ # Qt5Widgets.dll!QApplication::notify(QObject * receiver, QEvent * e) Line 3639 C++ # Qt5Core.dll!QCoreApplication::notifyInternal2(QObject * receiver, QEvent * event) Line 1075 C++ # [Inline Frame] Qt5Core.dll!QCoreApplication::sendEvent(QObject *) Line 1470 C++ # Qt5Core.dll!QCoreApplicationPrivate::sendPostedEvents(QObject * receiver, int event_type, QThreadData * data) Line 1815 C++ # qwindows.dll!QWindowsGuiEventDispatcher::sendPostedEvents() Line 82 C++ # Qt5Core.dll!QEventDispatcherWin32::processEvents(QFlags<enum QEventLoop::ProcessEventsFlag> flags) Line 525 C++ # qwindows.dll!QWindowsGuiEventDispatcher::processEvents(QFlags<enum QEventLoop::ProcessEventsFlag> flags) Line 75 C++ # Qt5Widgets.dll!QProgressDialog::setValue(int progress) Line 663 C++ # [Inline Frame] Qt5Core.dll!QtPrivate::QSlotObjectBase::call(QObject *) Line 398 C++ # Qt5Core.dll!QMetaCallEvent::placeMetaCall(QObject * object) Line 626 C++ # Qt5Core.dll!QObject::event(QEvent * e) Line 1339 C++ # Qt5Widgets.dll!QWidget::event(QEvent * event) Line 9094 C++ # Qt5Widgets.dll!QApplicationPrivate::notify_helper(QObject * receiver, QEvent * e) Line 3687 C++ # Qt5Widgets.dll!QApplication::notify(QObject * receiver, QEvent * e) Line 3639 C++ # Qt5Core.dll!QCoreApplication::notifyInternal2(QObject * receiver, QEvent * event) Line 1075 C++ # [Inline Frame] Qt5Core.dll!QCoreApplication::sendEvent(QObject *) Line 1470 C++ # Qt5Core.dll!QCoreApplicationPrivate::sendPostedEvents(QObject * receiver, int event_type, QThreadData * data) Line 1815 C++ # qwindows.dll!QWindowsGuiEventDispatcher::sendPostedEvents() Line 82 C++ # Qt5Core.dll!QEventDispatcherWin32::processEvents(QFlags<enum QEventLoop::ProcessEventsFlag> flags) Line 525 C++ # qwindows.dll!QWindowsGuiEventDispatcher::processEvents(QFlags<enum QEventLoop::ProcessEventsFlag> flags) Line 75 C++ # Qt5Widgets.dll!QProgressDialog::setValue(int progress) Line 663 C++ # [Inline Frame] Qt5Core.dll!QtPrivate::QSlotObjectBase::call(QObject *) Line 398 C++ # Qt5Core.dll!QMetaCallEvent::placeMetaCall(QObject * object) Line 626 C++ # Qt5Core.dll!QObject::event(QEvent * e) Line 1339 C++ # Qt5Widgets.dll!QWidget::event(QEvent * event) Line 9094 C++ # Qt5Widgets.dll!QApplicationPrivate::notify_helper(QObject * receiver, QEvent * e) Line 3687 C++ # Qt5Widgets.dll!QApplication::notify(QObject * receiver, QEvent * e) Line 3639 C++ # Qt5Core.dll!QCoreApplication::notifyInternal2(QObject * receiver, QEvent * event) Line 1075 C++ # [Inline Frame] Qt5Core.dll!QCoreApplication::sendEvent(QObject *) Line 1470 C++ # Qt5Core.dll!QCoreApplicationPrivate::sendPostedEvents(QObject * receiver, int event_type, QThreadData * data) Line 1815 C++ # qwindows.dll!QWindowsGuiEventDispatcher::sendPostedEvents() Line 82 C++ # Qt5Core.dll!QEventDispatcherWin32::processEvents(QFlags<enum QEventLoop::ProcessEventsFlag> flags) Line 525 C++ # qwindows.dll!QWindowsGuiEventDispatcher::processEvents(QFlags<enum QEventLoop::ProcessEventsFlag> flags) Line 75 C++ # [Inline Frame] Qt5Core.dll!QEventLoop::processEvents(QFlags<enum QEventLoop::ProcessEventsFlag>) Line 138 C++ # Qt5Core.dll!QEventLoop::exec(QFlags<enum QEventLoop::ProcessEventsFlag> flags) Line 225 C++ # Qt5Core.dll!QCoreApplication::exec() Line 1383 C++ # progress_bar.exe!main(int argc, char * * argv) Line 9 C++ # [External Code]
I did not put the ones that end up in stack overflow to avoid adding lines because in the two stack examples it can be already seen how the method is invoked recursively.
I have tested this in Windows 10, Visual Studio 16.5.2, MSVC 19.25.28612.0 and Qt 5.14.2 as well as Qt 5.14.1, Qt 5.9.5. Also, I have tried in Ubuntu 18.04, g++ 7.5.0 and Qt 5.9.5.