注意:我也在PyQt邮件列表上发布了这个问题 - 如果那里有一个好的答案,我会在这里回答自己的问题。
当执行QApplication.quit()
时,我遇到了偶尔出现的段错误问题,可能与libQt5Network.so和/或QtWebkit有关。
首先,我使用以下3个测试系统:
- Arch Linux,PyQt 5.2,Qt 5.2.0,Python 3.3.3
- Ubuntu 13.10,PyQt 5.0.1,Qt 5.0.2,Python 3.3.2在虚拟机中
- Windows 7,PyQt 5.2,Qt 5.2.0,Python 3.3.3
这些崩溃在Arch上从未发生过,但在Ubuntu上经常发生,在Windows上偶尔发生(尽管Windows只是一个猜测,我只是得到这个python.exe不再工作的提示)。
原始崩溃
我最初在一个大型项目qutebrowser中注意到了这个问题,在Ubuntu上键入:quit
时给了我这个堆栈跟踪:
#0 0xb5c296fc in QMutex::lock() () from /usr/lib/i386-linux-gnu/libQt5Core.so.5
#1 0xb3bdd97d in ?? () from /usr/lib/i386-linux-gnu/libQt5Network.so.5
#2 0xb3bdf0d0 in ?? () from /usr/lib/i386-linux-gnu/libQt5Network.so.5
#3 0xb3bd4418 in ?? () from /usr/lib/i386-linux-gnu/libQt5Network.so.5
#4 0xb3bd8b1e in ?? () from /usr/lib/i386-linux-gnu/libQt5Network.so.5
#5 0xb5dedf10 in QMetaObject::activate(QObject*, int, int, void**) ()
from /usr/lib/i386-linux-gnu/libQt5Core.so.5
#6 0xb5dee48b in QMetaObject::activate(QObject*, QMetaObject const*, int, void**) () from /usr/lib/i386-linux-gnu/libQt5Core.so.5
#7 0xb5e59155 in QIODevice::readyRead() ()
from /usr/lib/i386-linux-gnu/libQt5Core.so.5
#8 0xb3bb1f14 in ?? () from /usr/lib/i386-linux-gnu/libQt5Network.so.5
#9 0xb3ba4d99 in ?? () from /usr/lib/i386-linux-gnu/libQt5Network.so.5
#10 0xb3bc03bb in ?? () from /usr/lib/i386-linux-gnu/libQt5Network.so.5
#11 0xb6483a54 in QApplicationPrivate::notify_helper(QObject*, QEvent*) ()
from /usr/lib/i386-linux-gnu/libQt5Widgets.so.5
#12 0xb6488e66 in QApplication::notify(QObject*, QEvent*) ()
from /usr/lib/i386-linux-gnu/libQt5Widgets.so.5
#13 0xb6bb7e80 in sipQApplication::notify(QObject*, QEvent*) ()
from /usr/lib/python3/dist-packages/PyQt5/QtWidgets.cpython-33m-i386-linux-gnu.so
#14 0xb5dc737a in QCoreApplication::notifyInternal(QObject*, QEvent*) ()
from /usr/lib/i386-linux-gnu/libQt5Core.so.5
#15 0xb5e11f67 in ?? () from /usr/lib/i386-linux-gnu/libQt5Core.so.5
#16 0xb5aaf83e in g_main_context_dispatch ()
from /lib/i386-linux-gnu/libglib-2.0.so.0
#17 0xb5aafbe8 in ?? () from /lib/i386-linux-gnu/libglib-2.0.so.0
#18 0xb5aafca8 in g_main_context_iteration ()
from /lib/i386-linux-gnu/libglib-2.0.so.0
#19 0xb5e1138f in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/i386-linux-gnu/libQt5Core.so.5
#20 0xb5dc5c06 in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/i386-linux-gnu/libQt5Core.so.5
#21 0xb5dc6014 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) ()
from /usr/lib/i386-linux-gnu/libQt5Core.so.5
#22 0xb5c2b90b in QThread::exec() ()
from /usr/lib/i386-linux-gnu/libQt5Core.so.5
#23 0xb5c2b99b in QThread::run() () from /usr/lib/i386-linux-gnu/libQt5Core.so.5
#24 0xb5c2fa08 in ?? () from /usr/lib/i386-linux-gnu/libQt5Core.so.5
#25 0xb7774d78 in start_thread (arg=0xa5314b40) at pthread_create.c:311
#26 0xb76ac01e in clone () at ../sysdeps/unix/sysv/linux/i386/clone.S:131
这里是核心转储文件(15MB,gzip)。
最简单的示例
然后我用一个简单的示例再试了一次,使用QTimer自动在一秒钟后退出。在它崩溃之前,我必须循环运行大约一分钟左右:
from PyQt5.QtCore import QUrl, QTimer
from PyQt5.QtWidgets import QApplication
from PyQt5.QtWebKitWidgets import QWebView
app = QApplication([])
wv = QWebView()
wv.load(QUrl("http://www.heise.de/"))
t = QTimer()
t.timeout.connect(QApplication.quit)
t.start(1000)
wv.show()
app.exec_()
这给了我一个非常相似的堆栈跟踪(在Ubuntu上):
#0 0xb6cfd8d2 in QCoreApplication::postEvent(QObject*, QEvent*, int) ()
from /usr/lib/i386-linux-gnu/libQt5Core.so.5
#1 0xb6d21c83 in QMetaObject::activate(QObject*, int, int, void**) ()
from /usr/lib/i386-linux-gnu/libQt5Core.so.5
#2 0xb6d2248b in QMetaObject::activate(QObject*, QMetaObject const*, int, void**) () from /usr/lib/i386-linux-gnu/libQt5Core.so.5
#3 0xb3e47935 in ?? () from /usr/lib/i386-linux-gnu/libQt5Network.so.5
#4 0xb3dcf687 in ?? () from /usr/lib/i386-linux-gnu/libQt5Network.so.5
#5 0xb3e483b3 in ?? () from /usr/lib/i386-linux-gnu/libQt5Network.so.5
#6 0xb6d21f10 in QMetaObject::activate(QObject*, int, int, void**) ()
from /usr/lib/i386-linux-gnu/libQt5Core.so.5
#7 0xb6d2248b in QMetaObject::activate(QObject*, QMetaObject const*, int, void**) () from /usr/lib/i386-linux-gnu/libQt5Core.so.5
#8 0xb3e43fe5 in ?? () from /usr/lib/i386-linux-gnu/libQt5Network.so.5
#9 0xb3d93b1e in ?? () from /usr/lib/i386-linux-gnu/libQt5Network.so.5
#10 0xb3d94630 in ?? () from /usr/lib/i386-linux-gnu/libQt5Network.so.5
#11 0xb3d9471b in ?? () from /usr/lib/i386-linux-gnu/libQt5Network.so.5
#12 0xb6d21f10 in QMetaObject::activate(QObject*, int, int, void**) ()
from /usr/lib/i386-linux-gnu/libQt5Core.so.5
#13 0xb6d2248b in QMetaObject::activate(QObject*, QMetaObject const*, int, void**) () from /usr/lib/i386-linux-gnu/libQt5Core.so.5
#14 0xb6d8d155 in QIODevice::readyRead() ()
from /usr/lib/i386-linux-gnu/libQt5Core.so.5
#15 0xb3e09f14 in ?? () from /usr/lib/i386-linux-gnu/libQt5Network.so.5
#16 0xb3dfcd99 in ?? () from /usr/lib/i386-linux-gnu/libQt5Network.so.5
#17 0xb3e183bb in ?? () from /usr/lib/i386-linux-gnu/libQt5Network.so.5
#18 0xb492ba54 in QApplicationPrivate::notify_helper(QObject*, QEvent*) ()
from /usr/lib/i386-linux-gnu/libQt5Widgets.so.5
#19 0xb4930e66 in QApplication::notify(QObject*, QEvent*) ()
from /usr/lib/i386-linux-gnu/libQt5Widgets.so.5
#20 0xb505fe80 in sipQApplication::notify(QObject*, QEvent*) ()
from /usr/lib/python3/dist-packages/PyQt5/QtWidgets.cpython-33m-i386-linux-gnu.so
#21 0xb6cfb37a in QCoreApplication::notifyInternal(QObject*, QEvent*) ()
from /usr/lib/i386-linux-gnu/libQt5Core.so.5
#22 0xb6d45f67 in ?? () from /usr/lib/i386-linux-gnu/libQt5Core.so.5
#23 0xb65f483e in g_main_context_dispatch ()
from /lib/i386-linux-gnu/libglib-2.0.so.0
#24 0xb65f4be8 in ?? () from /lib/i386-linux-gnu/libglib-2.0.so.0
#25 0xb65f4ca8 in g_main_context_iteration ()
from /lib/i386-linux-gnu/libglib-2.0.so.0
#26 0xb6d4536d in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/i386-linux-gnu/libQt5Core.so.5
#27 0xb6cf9c06 in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/i386-linux-gnu/libQt5Core.so.5
#28 0xb6cfa014 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) ()
from /usr/lib/i386-linux-gnu/libQt5Core.so.5
#29 0xb6b5f90b in QThread::exec() ()
from /usr/lib/i386-linux-gnu/libQt5Core.so.5
#30 0xb6b5f99b in QThread::run() () from /usr/lib/i386-linux-gnu/libQt5Core.so.5
#31 0xb6b63a08 in ?? () from /usr/lib/i386-linux-gnu/libQt5Core.so.5
#32 0xb7798d78 in start_thread (arg=0xa7812b40) at pthread_create.c:311
#33 0xb76d001e in clone () at ../sysdeps/unix/sysv/linux/i386/clone.S:131
在此处生成核心转储文件(15MB,gzip)。有人知道这里出了什么问题吗?是否与垃圾回收的方式有关?我还尝试了一些解决 PyQt4 相似症状的方法,但也没有帮助。
* 找不到描述它的 StackOverflow 答案 - 基本上在运行
exec_()
之前将 QtWidgets.qApp
设置为 QApplication
实例,并在之后设置为 None
。
deleteLater
方法也是异步的,所以可能会发生的情况是,你的shutdown
方法完成后,deleteLater
被调度,应用程序退出,但对象并没有被真正快速地删除。我通过将destroyed
信号连接到一个方法来解决这个问题,在该方法中检查是否成功删除了所有组件,然后才允许应用程序退出。 - andrean