Details
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Bug
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Resolution: Done
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P1: Critical
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None
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5.14.2
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None
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270d2be98ad72e0cffb20339c3a42c8f81e3b8ec (pyside/pyside-setup/5.14)
Description
Between 5.14.1 and 5.14.2, a regression was introduced, causing a deadlock out of the box with one of our tools (https://github.com/gopro/gopro-lib-node.gl/).
You'll need the following 3 files to reproduce the issue:
1. qtbug.pyx:
cdef class X:
def nogil_noop(self):
with nogil:
pass
2. setup.py:
from setuptools import setup
from Cython.Build import cythonize
setup(ext_modules = cythonize("qtbug.pyx"))
3. runme.py:
from PySide2 import QtCore, QtWidgets
from PySide2.QtCore import QEvent
import qtbug
class _Thread(QtCore.QThread):
def __init__(self):
super().__init__()
self._mutex = QtCore.QMutex()
self._pyx = qtbug.X()
def run(self):
while True:
with QtCore.QMutexLocker(self._mutex):
self._pyx.nogil_noop()
def draw(self):
with QtCore.QMutexLocker(self._mutex):
pass
class _Widget(QtWidgets.QWidget):
def __init__(self):
super().__init__()
self._thread = _Thread()
self._thread.start()
def event(self, event):
print(event)
if event.type() == QEvent.Paint:
self._thread.draw()
return super().event(event)
if __name__ == '__main__':
import sys
app = QtWidgets.QApplication(sys.argv)
window = _Widget()
window.show()
app.exec_()
To reproduce:
# Create and enter a Python virtualenv virtualenv venv . venv/bin/activate # Build the small binding pip install cython python setup.py build_ext --inplace # Install PySide and run the script pip install -U pyside2==5.14.2.1 python runme.py
If it doesn't deadlock right away, resizing the window will.
To compare with a working version:
pip install -U pyside2==5.14.1 python runme.py
Following is the backtrace with that test case:
(gdb) bt #0 0x00007ffff7ec3f8d in syscall () from /usr/lib/libc.so.6 #1 0x00007ffff5a8d6f5 in QBasicMutex::lockInternal() () from /home/ux/tmp/pyside-bug/venv/lib/python3.8/site-packages/PySide2/Qt/lib/libQt5Core.so.5 #2 0x00007ffff5a8d746 in QMutex::lock() () from /home/ux/tmp/pyside-bug/venv/lib/python3.8/site-packages/PySide2/Qt/lib/libQt5Core.so.5 #3 0x00007ffff65c7687 in Sbk_QMutexLocker_Init () from /home/ux/tmp/pyside-bug/venv/lib/python3.8/site-packages/PySide2/QtCore.abi3.so #4 0x00007ffff7b401aa in _PyObject_MakeTpCall () from /usr/lib/libpython3.8.so.1.0 #5 0x00007ffff7bfdc51 in _PyEval_EvalFrameDefault () from /usr/lib/libpython3.8.so.1.0 #6 0x00007ffff7beb1d6 in ?? () from /usr/lib/libpython3.8.so.1.0 #7 0x00007ffff7bfd80a in _PyEval_EvalFrameDefault () from /usr/lib/libpython3.8.so.1.0 #8 0x00007ffff7be98f4 in _PyEval_EvalCodeWithName () from /usr/lib/libpython3.8.so.1.0 #9 0x00007ffff7beac7b in _PyFunction_Vectorcall () from /usr/lib/libpython3.8.so.1.0 #10 0x00007ffff7beb4ab in ?? () from /usr/lib/libpython3.8.so.1.0 #11 0x00007ffff7b463fd in PyObject_Call () from /usr/lib/libpython3.8.so.1.0 #12 0x00007ffff2306bb2 in QWidgetWrapper::event(QEvent*) () from /home/ux/tmp/pyside-bug/venv/lib/python3.8/site-packages/PySide2/QtWidgets.abi3.so #13 0x00007ffff15e8b0c in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /home/ux/tmp/pyside-bug/venv/lib/python3.8/site-packages/PySide2/Qt/lib/libQt5Widgets.so.5 #14 0x00007ffff15efa90 in QApplication::notify(QObject*, QEvent*) () from /home/ux/tmp/pyside-bug/venv/lib/python3.8/site-packages/PySide2/Qt/lib/libQt5Widgets.so.5 #15 0x00007ffff1e77565 in QApplicationWrapper::notify(QObject*, QEvent*) () from /home/ux/tmp/pyside-bug/venv/lib/python3.8/site-packages/PySide2/QtWidgets.abi3.so #16 0x00007ffff5c6fc48 in QCoreApplication::notifyInternal2(QObject*, QEvent*) () from /home/ux/tmp/pyside-bug/venv/lib/python3.8/site-packages/PySide2/Qt/lib/libQt5Core.so.5 #17 0x00007ffff16200c5 in QWidgetPrivate::sendPaintEvent(QRegion const&) () from /home/ux/tmp/pyside-bug/venv/lib/python3.8/site-packages/PySide2/Qt/lib/libQt5Widgets.so.5 #18 0x00007ffff1620bc7 in QWidgetPrivate::drawWidget(QPaintDevice*, QRegion const&, QPoint const&, QFlags<QWidgetPrivate::DrawWidgetFlag>, QPainter*, QWidgetRepaintManager*) () from /home/ux/tmp/pyside-bug/venv/lib/python3.8/site-packages/PySide2/Qt/lib/libQt5Widgets.so.5 #19 0x00007ffff15f8f7f in QWidgetRepaintManager::paintAndFlush() () from /home/ux/tmp/pyside-bug/venv/lib/python3.8/site-packages/PySide2/Qt/lib/libQt5Widgets.so.5 #20 0x00007ffff15f9648 in QWidgetRepaintManager::sync() () from /home/ux/tmp/pyside-bug/venv/lib/python3.8/site-packages/PySide2/Qt/lib/libQt5Widgets.so.5 #21 0x00007ffff162174f in QWidgetPrivate::syncBackingStore() () from /home/ux/tmp/pyside-bug/venv/lib/python3.8/site-packages/PySide2/Qt/lib/libQt5Widgets.so.5 #22 0x00007ffff16403d7 in QWidgetWindow::handleResizeEvent(QResizeEvent*) () from /home/ux/tmp/pyside-bug/venv/lib/python3.8/site-packages/PySide2/Qt/lib/libQt5Widgets.so.5 #23 0x00007ffff164391b in QWidgetWindow::event(QEvent*) () from /home/ux/tmp/pyside-bug/venv/lib/python3.8/site-packages/PySide2/Qt/lib/libQt5Widgets.so.5 #24 0x00007ffff15e8b0c in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /home/ux/tmp/pyside-bug/venv/lib/python3.8/site-packages/PySide2/Qt/lib/libQt5Widgets.so.5 #25 0x00007ffff15efa90 in QApplication::notify(QObject*, QEvent*) () from /home/ux/tmp/pyside-bug/venv/lib/python3.8/site-packages/PySide2/Qt/lib/libQt5Widgets.so.5 #26 0x00007ffff1e77565 in QApplicationWrapper::notify(QObject*, QEvent*) () from /home/ux/tmp/pyside-bug/venv/lib/python3.8/site-packages/PySide2/QtWidgets.abi3.so #27 0x00007ffff5c6fc48 in QCoreApplication::notifyInternal2(QObject*, QEvent*) () from /home/ux/tmp/pyside-bug/venv/lib/python3.8/site-packages/PySide2/Qt/lib/libQt5Core.so.5 #28 0x00007ffff0cd452c in QGuiApplicationPrivate::processGeometryChangeEvent(QWindowSystemInterfacePrivate::GeometryChangeEvent*) () from /home/ux/tmp/pyside-bug/venv/lib/python3.8/site-packages/PySide2/Qt/lib/libQt5Gui.so.5 #29 0x00007ffff0cd8d2d in QGuiApplicationPrivate::processWindowSystemEvent(QWindowSystemInterfacePrivate::WindowSystemEvent*) () from /home/ux/tmp/pyside-bug/venv/lib/python3.8/site-packages/PySide2/Qt/lib/libQt5Gui.so.5 #30 0x00007ffff0cb4f4b in QWindowSystemInterface::sendWindowSystemEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /home/ux/tmp/pyside-bug/venv/lib/python3.8/site-packages/PySide2/Qt/lib/libQt5Gui.so.5 #31 0x00007fffef9ac33a in xcbSourceDispatch(_GSource*, int (*)(void*), void*) () from /home/ux/tmp/pyside-bug/venv/lib/python3.8/site-packages/PySide2/Qt/plugins/platforms/../../lib/libQt5XcbQpa.so.5 #32 0x00007ffff2cf16be in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0 #33 0x00007ffff2cf3531 in ?? () from /usr/lib/libglib-2.0.so.0 #34 0x00007ffff2cf3571 in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0 #35 0x00007ffff5cc873c in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /home/ux/tmp/pyside-bug/venv/lib/python3.8/site-packages/PySide2/Qt/lib/libQt5Core.so.5 #36 0x00007ffff5c6e662 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /home/ux/tmp/pyside-bug/venv/lib/python3.8/site-packages/PySide2/Qt/lib/libQt5Core.so.5 #37 0x00007ffff5c77590 in QCoreApplication::exec() () from /home/ux/tmp/pyside-bug/venv/lib/python3.8/site-packages/PySide2/Qt/lib/libQt5Core.so.5 #38 0x00007ffff1e75038 in Sbk_QApplicationFunc_exec_ () from /home/ux/tmp/pyside-bug/venv/lib/python3.8/site-packages/PySide2/QtWidgets.abi3.so #39 0x00007ffff7a8d587 in ?? () from /usr/lib/libpython3.8.so.1.0 #40 0x00007ffff7bfd80a in _PyEval_EvalFrameDefault () from /usr/lib/libpython3.8.so.1.0 #41 0x00007ffff7be98f4 in _PyEval_EvalCodeWithName () from /usr/lib/libpython3.8.so.1.0 #42 0x00007ffff7c70d73 in PyEval_EvalCode () from /usr/lib/libpython3.8.so.1.0 #43 0x00007ffff7c70dc8 in ?? () from /usr/lib/libpython3.8.so.1.0 #44 0x00007ffff7c75063 in ?? () from /usr/lib/libpython3.8.so.1.0 #45 0x00007ffff7b0fdf0 in PyRun_FileExFlags () from /usr/lib/libpython3.8.so.1.0 #46 0x00007ffff7b19aa4 in PyRun_SimpleFileExFlags () from /usr/lib/libpython3.8.so.1.0 #47 0x00007ffff7c8181e in Py_RunMain () from /usr/lib/libpython3.8.so.1.0 #48 0x00007ffff7c81909 in Py_BytesMain () from /usr/lib/libpython3.8.so.1.0 #49 0x00007ffff7df1023 in __libc_start_main () from /usr/lib/libc.so.6 #50 0x000055555555505e in _start () (gdb)
Note the use of the with nogil in the Cython binding.