Fix tst_QEventLoop::exec() regression introduced by commit 816523117bc00cfeb17e347f7fe5f11278a5e871

The quitNow flag needs to be reset at the beginning of exec() to allow
exec() to recurse and be run multiple times.

This changes reverts commit 816523117bc00cfeb17e347f7fe5f11278a5e871 an
introduces the QThreadPrivate::exited flag to fix the race between
start() and exit(), and QThreadPrivate::returnCode to make sure exec()
returns the code passed to exit().

Task-number: QTBUG-1184
Reviewed-by: olivier

1 files changed, 12 insertions, 3 deletions

diff --git a/src/corelib/thread/qthread.cpp b/src/corelib/thread/qthread.cpp
index cdcb65c..2c63dfc 100644
--- a/src/corelib/thread/qthread.cpp
+++ b/src/corelib/thread/qthread.cpp
@@ -173,7 +173,7 @@ void QAdoptedThread::run()
 */
 
 QThreadPrivate::QThreadPrivate(QThreadData *d)
-    : QObjectPrivate(), running(false), finished(false), terminated(false),
+    : QObjectPrivate(), running(false), finished(false), terminated(false), exited(false), returnCode(-1),
       stackSize(0), priority(QThread::InheritPriority), data(d)
 {
 #if defined (Q_OS_UNIX)
@@ -480,11 +480,18 @@ uint QThread::stackSize() const
 int QThread::exec()
 {
     Q_D(QThread);
+    QMutexLocker locker(&d->mutex);
+    d->data->quitNow = false;
+    if (d->exited)
+        return d->returnCode;
+    locker.unlock();
+
     QEventLoop eventLoop;
     int returnCode = eventLoop.exec();
 
-    QMutexLocker locker(&d->mutex);
-    d->data->quitNow = false;
+    locker.relock();
+    d->exited = false;
+    d->returnCode = -1;
     return returnCode;
 }
 
@@ -511,6 +518,8 @@ void QThread::exit(int returnCode)
 {
     Q_D(QThread);
     QMutexLocker locker(&d->mutex);
+    d->exited = true;
+    d->returnCode = returnCode;
     d->data->quitNow = true;
     for (int i = 0; i < d->data->eventLoops.size(); ++i) {
         QEventLoop *eventLoop = d->data->eventLoops.at(i);