Fix two data races in QThread/QThreadData

* theMainThread is written by the main thread and read by
   QThreadData::~QThreadData() (any managed thread)

* QThreadData::thread is written by QThread::~QThread (in the parent thread)
  and read+written by QThreadData::~QThreadData (in the managed thread).
  This can happen because QThreadData is refcounted so the managed
  thread (which derefs it) races with the parent thread (which sets it to 0).

Change-Id: I72de793716391a0937254cda6b4328fcad5060c7
Reviewed-by: Olivier Goffart (Woboq GmbH) <ogoffart@woboq.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/src/corelib/kernel/qobject.cpp b/src/corelib/kernel/qobject.cpp
index bcc4e7f8e6..f2c67fb3a0 100644
--- a/src/corelib/kernel/qobject.cpp
+++ b/src/corelib/kernel/qobject.cpp
@@ -1468,7 +1468,7 @@ void QObject::moveToThread(QThread *targetThread)
     } else if (d->threadData != currentData) {
         qWarning("QObject::moveToThread: Current thread (%p) is not the object's thread (%p).\n"
                  "Cannot move to target thread (%p)\n",
-                 currentData->thread, d->threadData->thread, targetData ? targetData->thread : Q_NULLPTR);
+                 currentData->thread.load(), d->threadData->thread.load(), targetData ? targetData->thread.load() : Q_NULLPTR);
 
 #ifdef Q_OS_MAC
         qWarning("You might be loading two sets of Qt binaries into the same process. "