Merge "QEventDispatcher(Win): Always honor interrupted status to avoid races"

6 files changed, 39 insertions, 3 deletions

diff --git a/src/corelib/doc/snippets/code/src_corelib_kernel_qdeadlinetimer.cpp b/src/corelib/doc/snippets/code/src_corelib_kernel_qdeadlinetimer.cpp
index 35c06f842e..5858b6a78d 100644
--- a/src/corelib/doc/snippets/code/src_corelib_kernel_qdeadlinetimer.cpp
+++ b/src/corelib/doc/snippets/code/src_corelib_kernel_qdeadlinetimer.cpp
@@ -53,7 +53,7 @@
     {
         QDeadlineTimer deadline(msecs);
         do {
-            if (readFromDevice(deadline.remainingTime())
+            if (readFromDevice(deadline.remainingTime()))
                 break;
             waitForReadyRead(deadline);
         } while (!deadline.hasExpired());
diff --git a/src/corelib/kernel/qeventdispatcher_win.cpp b/src/corelib/kernel/qeventdispatcher_win.cpp
index 19604de32f..80297feef1 100644
--- a/src/corelib/kernel/qeventdispatcher_win.cpp
+++ b/src/corelib/kernel/qeventdispatcher_win.cpp
@@ -475,13 +475,17 @@ bool QEventDispatcherWin32::processEvents(QEventLoop::ProcessEventsFlags flags)
 {
     Q_D(QEventDispatcherWin32);
 
-    d->interrupt.storeRelaxed(false);
+    // We don't know _when_ the interrupt occurred so we have to honor it.
+    const bool wasInterrupted = d->interrupt.fetchAndStoreRelaxed(false);
     emit awake();
 
     // To prevent livelocks, send posted events once per iteration.
     // QCoreApplication::sendPostedEvents() takes care about recursions.
     sendPostedEvents();
 
+    if (wasInterrupted)
+        return false;
+
     auto threadData = d->threadData.loadRelaxed();
     bool canWait;
     bool retVal = false;
diff --git a/tests/auto/corelib/kernel/qeventdispatcher/tst_qeventdispatcher.cpp b/tests/auto/corelib/kernel/qeventdispatcher/tst_qeventdispatcher.cpp
index 8d69314fa5..21aee94e5d 100644
--- a/tests/auto/corelib/kernel/qeventdispatcher/tst_qeventdispatcher.cpp
+++ b/tests/auto/corelib/kernel/qeventdispatcher/tst_qeventdispatcher.cpp
@@ -71,6 +71,7 @@ private slots:
     void processEventsOnlySendsQueuedEvents();
     void postedEventsPingPong();
     void eventLoopExit();
+    void interruptTrampling();
 };
 
 bool tst_QEventDispatcher::event(QEvent *e)
@@ -421,5 +422,31 @@ void tst_QEventDispatcher::eventLoopExit()
     QVERIFY(!timeoutObserved);
 }
 
+// Based on QTBUG-91539: In the event dispatcher on Windows we overwrite the
+// interrupt once we start processing events (this pattern is also in the 'unix' dispatcher)
+// which would lead the dispatcher to accidentally ignore certain interrupts and,
+// as in the bug report, would not quit, leaving the thread alive and running.
+void tst_QEventDispatcher::interruptTrampling()
+{
+    class WorkerThread : public QThread
+    {
+        void run() override {
+            auto dispatcher = eventDispatcher();
+            QVERIFY(dispatcher);
+            dispatcher->processEvents(QEventLoop::AllEvents);
+            QTimer::singleShot(0, [dispatcher]() {
+                dispatcher->wakeUp();
+            });
+            dispatcher->processEvents(QEventLoop::WaitForMoreEvents);
+            dispatcher->interrupt();
+            dispatcher->processEvents(QEventLoop::WaitForMoreEvents);
+        }
+    };
+    WorkerThread thread;
+    thread.start();
+    QVERIFY(thread.wait(1000));
+    QVERIFY(thread.isFinished());
+}
+
 QTEST_MAIN(tst_QEventDispatcher)
 #include "tst_qeventdispatcher.moc"
diff --git a/tests/auto/gui/kernel/qshortcut/tst_qshortcut.cpp b/tests/auto/gui/kernel/qshortcut/tst_qshortcut.cpp
index fc230f98e2..777f486263 100644
--- a/tests/auto/gui/kernel/qshortcut/tst_qshortcut.cpp
+++ b/tests/auto/gui/kernel/qshortcut/tst_qshortcut.cpp
@@ -74,6 +74,7 @@ void tst_QShortcut::trigger()
     new QShortcut(Qt::CTRL | Qt::Key_Q, &w, SLOT(close()));
     w.show();
     QVERIFY(QTest::qWaitForWindowExposed(&w));
+    QTRY_VERIFY(QGuiApplication::applicationState() == Qt::ApplicationActive);
     sendKey(&w, Qt::Key_Q, 'q', Qt::ControlModifier);
     QTRY_VERIFY(!w.isVisible());
 }
diff --git a/tests/auto/gui/qopengl/tst_qopengl.cpp b/tests/auto/gui/qopengl/tst_qopengl.cpp
index 9e66ec9a43..e2e7f153a0 100644
--- a/tests/auto/gui/qopengl/tst_qopengl.cpp
+++ b/tests/auto/gui/qopengl/tst_qopengl.cpp
@@ -1480,6 +1480,9 @@ void tst_QOpenGL::glxContextWrap()
     if (QGuiApplication::platformName().startsWith(QLatin1String("offscreen"), Qt::CaseInsensitive))
         QSKIP("Offscreen: This fails.");
 
+    if (QGuiApplication::platformName().startsWith(QLatin1String("wayland"), Qt::CaseInsensitive))
+        QSKIP("Fails on Wayland.");
+
     QWindow *window = new QWindow;
     window->setSurfaceType(QWindow::OpenGLSurface);
     window->setGeometry(0, 0, 10, 10);
diff --git a/tests/auto/widgets/dialogs/qdialog/tst_qdialog.cpp b/tests/auto/widgets/dialogs/qdialog/tst_qdialog.cpp
index 53c33255bf..6a59edca10 100644
--- a/tests/auto/widgets/dialogs/qdialog/tst_qdialog.cpp
+++ b/tests/auto/widgets/dialogs/qdialog/tst_qdialog.cpp
@@ -552,10 +552,11 @@ void tst_QDialog::keepPositionOnClose()
     dialog.setWindowTitle(QTest::currentTestFunction());
     const QRect availableGeometry = QGuiApplication::primaryScreen()->availableGeometry();
     dialog.resize(availableGeometry.size() / 4);
-    const QPoint pos = availableGeometry.topLeft() + QPoint(100, 100);
+    QPoint pos = availableGeometry.topLeft() + QPoint(100, 100);
     dialog.move(pos);
     dialog.show();
     QVERIFY(QTest::qWaitForWindowExposed(&dialog));
+    pos = dialog.pos();
     dialog.close();
     dialog.windowHandle()->destroy(); // Emulate a click on close by destroying the window.
     QTest::qWait(50);