Fix race condition in the non-GL case

Make sure to also flush output when waiting for an ack from the
compositor, in case we haven't sent the frame request yet.

Reviewed-by: Jørgen

3 files changed, 12 insertions, 5 deletions

diff --git a/src/plugins/platforms/wayland/qwaylanddisplay.cpp b/src/plugins/platforms/wayland/qwaylanddisplay.cpp
index d0a0725..27f4334 100644
--- a/src/plugins/platforms/wayland/qwaylanddisplay.cpp
+++ b/src/plugins/platforms/wayland/qwaylanddisplay.cpp
@@ -141,7 +141,12 @@ void QWaylandDisplay::displayHandleGlobal(struct wl_display *display,
     }
 }
 
-void QWaylandDisplay::eventDispatcher(void)
+void QWaylandDisplay::iterate()
+{
+    wl_display_iterate(mDisplay, WL_DISPLAY_READABLE | WL_DISPLAY_WRITABLE);
+}
+
+void QWaylandDisplay::readEvents(void)
 {
     wl_display_iterate(mDisplay, WL_DISPLAY_READABLE);
 }
@@ -189,7 +194,7 @@ QWaylandDisplay::QWaylandDisplay(void)
     mNativeEglDisplay = 0;
 #endif
 
-    eventDispatcher();
+    readEvents();
 
 #ifdef QT_WAYLAND_GL_SUPPORT
     mEglDisplay = eglGetDisplay((EGLNativeDisplayType)mNativeEglDisplay);
@@ -208,7 +213,7 @@ QWaylandDisplay::QWaylandDisplay(void)
     int fd = wl_display_get_fd(mDisplay, sourceUpdate, this);
     mReadNotifier = new QSocketNotifier(fd, QSocketNotifier::Read, this);
     connect(mReadNotifier,
-            SIGNAL(activated(int)), this, SLOT(eventDispatcher()));
+            SIGNAL(activated(int)), this, SLOT(readEvents()));
 
     mWriteNotifier = new QSocketNotifier(fd, QSocketNotifier::Write, this);
     connect(mWriteNotifier,
diff --git a/src/plugins/platforms/wayland/qwaylanddisplay.h b/src/plugins/platforms/wayland/qwaylanddisplay.h
index ca31756..d994ffe 100644
--- a/src/plugins/platforms/wayland/qwaylanddisplay.h
+++ b/src/plugins/platforms/wayland/qwaylanddisplay.h
@@ -81,8 +81,10 @@ public:
     void syncCallback(wl_display_sync_func_t func, void *data);
     void frameCallback(wl_display_frame_func_t func, void *data);
 
+    void iterate();
+
 public slots:
-    void eventDispatcher(void);
+    void readEvents(void);
     void flushRequests(void);
 
 private:
diff --git a/src/plugins/platforms/wayland/qwaylandshmsurface.cpp b/src/plugins/platforms/wayland/qwaylandshmsurface.cpp
index b1cba71..6872bac 100644
--- a/src/plugins/platforms/wayland/qwaylandshmsurface.cpp
+++ b/src/plugins/platforms/wayland/qwaylandshmsurface.cpp
@@ -111,7 +111,7 @@ QPaintDevice *QWaylandShmWindowSurface::paintDevice()
 void QWaylandShmWindowSurface::beginPaint(const QRegion &)
 {
     while (mWaitingForFrameSync) {
-        mDisplay->eventDispatcher();
+        mDisplay->iterate();
     }
 }