Details
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Bug
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Resolution: Done
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P2: Important
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5.8.0, 5.9.0 Alpha
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None
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qtbase dev, clang 3.9.1, libc++, tsan
Description
qthread_unix.cpp:338 says data->threadId = to_HANDLE(pthread_self());
inside QMutexLocker locker(&thr->d_func()->mutex);
However this is being read without any mutex in QMetaObject::activate, see
qobject.cpp:3711 :
const bool receiverInSameThread = currentThreadId == receiver->d_func()>threadData>threadId;
Found by clang's tsan:
WARNING: ThreadSanitizer: data race (pid=9143) Write of size 8 at 0x7d2000003ec0 by thread T9: #0 QThreadPrivate::start(void*) /d/qt/5/kdab/qtbase-dev/src/corelib/thread/qthread_unix.cpp:338:24 (libQt5Core.so.5+0x0000000ffd1c) Previous read of size 8 at 0x7d2000003ec0 by thread T3: #0 QMetaObject::activate(QObject*, int, int, void**) /d/qt/5/kdab/qtbase-dev/src/corelib/kernel/qobject.cpp:3711:98 (libQt5Core.so.5+0x00000063aca0) #1 QMetaObject::activate(QObject*, QMetaObject const*, int, void**) /d/qt/5/kdab/qtbase-dev/src/corelib/kernel/qobject.cpp:3627:5 (libQt5Core.so.5+0x00000063a746) #2 QDBusConnectionManager::connectionRequested(QDBusConnectionManager::ConnectionRequestData*) /d/qt/5/kdab/qtbase-dev/build/src/dbus/.moc/moc_qdbusconnectionmanager_p.cpp:143:5 (libQt5DBus.so.5+0x0000000ccdf0) #3 QDBusConnectionManager::connectToBus(QDBusConnection::BusType, QString const&, bool) /d/qt/5/kdab/qtbase-dev/src/dbus/qdbusconnection.cpp:207:10 (libQt5DBus.so.5+0x0000000197c0) #4 QDBusConnectionManager::busConnection(QDBusConnection::BusType) /d/qt/5/kdab/qtbase-dev/src/dbus/qdbusconnection.cpp:116:33 (libQt5DBus.so.5+0x000000019583) #5 QDBusConnection::sessionBus() /d/qt/5/kdab/qtbase-dev/src/dbus/qdbusconnection.cpp:1177:42 (libQt5DBus.so.5+0x00000001d8a4)
Attachments
For Gerrit Dashboard: QTBUG-58855 | ||||||
---|---|---|---|---|---|---|
# | Subject | Branch | Project | Status | CR | V |
185656,4 | Turn QThreadData::threadId into a QAtomicPointer | 5.8 | qt/qtbase | Status: MERGED | +2 | 0 |