Complete rewrite of threaded render loop.

This change starts using the superior implementation of the scene graph
render loop which has been worked on in the scenegraph-playground
project for a while. It uses a far more straightforward locking/sync
paradigm compared to the existing one and is less deadlock and error
prone. It also enables the scene graph thread to run on its own when
the GUI thread is blocked, enabling threaded animations.

This changes also introduces a naming change inside Qt Quick from
"Window Manager" -> "Render Loop" as that fits better to what the
code does.

Change-Id: I1c2170ee04fcbef79660bd7dae6cace647cdb276
Reviewed-by: Samuel Rødal <samuel.rodal@digia.com>

17 files changed, 1279 insertions, 1168 deletions

diff --git a/src/quick/designer/designersupport.cpp b/src/quick/designer/designersupport.cpp
index 924dfe9551..915c87e51e 100644
--- a/src/quick/designer/designersupport.cpp
+++ b/src/quick/designer/designersupport.cpp
@@ -47,7 +47,7 @@
 #include <QtQml/private/qabstractanimationjob_p.h>
 #include <private/qqmlengine_p.h>
 #include <private/qquickview_p.h>
-#include <private/qquickwindowmanager_p.h>
+#include <private/qsgrenderloop_p.h>
 #include <QtQuick/private/qquickstategroup_p.h>
 #include <QtGui/QImage>
 #include <private/qqmlvme_p.h>
@@ -428,7 +428,7 @@ void DesignerSupport::updateDirtyNode(QQuickItem *item)
 
 void DesignerSupport::activateDesignerWindowManager()
 {
-    QQuickWindowManager::setInstance(new DesignerWindowManager);
+    QSGRenderLoop::setInstance(new DesignerWindowManager);
 }
 
 void DesignerSupport::activateDesignerMode()
diff --git a/src/quick/designer/designerwindowmanager_p.h b/src/quick/designer/designerwindowmanager_p.h
index 0e95b06197..878d236314 100644
--- a/src/quick/designer/designerwindowmanager_p.h
+++ b/src/quick/designer/designerwindowmanager_p.h
@@ -55,7 +55,7 @@
 
 #include <QtCore/QScopedPointer>
 
-#include <private/qquickwindowmanager_p.h>
+#include <private/qsgrenderloop_p.h>
 #include <private/qtquickglobal_p.h>
 #include <QtQuick/private/qsgcontext_p.h>
 
@@ -69,7 +69,7 @@ class QSGContext;
 class QAnimationDriver;
 class QOpenGLContext;
 
-class DesignerWindowManager : public QObject, public QQuickWindowManager
+class DesignerWindowManager : public QObject, public QSGRenderLoop
 {
     Q_OBJECT
 public:
@@ -88,7 +88,7 @@ public:
     void maybeUpdate(QQuickWindow *window);
     void update(QQuickWindow *window); // identical for this implementation.
 
-    void releaseResources() { }
+    void releaseResources(QQuickWindow *) { }
 
     QAnimationDriver *animationDriver() const { return 0; }
 
diff --git a/src/quick/items/context2d/qquickcontext2d.cpp b/src/quick/items/context2d/qquickcontext2d.cpp
index a46cd6ab70..c857a69f75 100644
--- a/src/quick/items/context2d/qquickcontext2d.cpp
+++ b/src/quick/items/context2d/qquickcontext2d.cpp
@@ -62,7 +62,6 @@
 #include <private/qv8domerrors_p.h>
 #include <QtCore/qnumeric.h>
 #include <private/qquickwindow_p.h>
-#include <private/qquickwindowmanager_p.h>
 
 #if defined(Q_OS_QNX) || defined(Q_OS_LINUX_ANDROID)
 #include <ctype.h>
@@ -3348,7 +3347,6 @@ QQuickContext2D::QQuickContext2D(QObject *parent)
     : QQuickCanvasContext(parent)
     , m_buffer(new QQuickContext2DCommandBuffer)
     , m_v8engine(0)
-    , m_windowManager(0)
     , m_surface(0)
     , m_glContext(0)
     , m_thread(0)
@@ -3380,7 +3378,6 @@ void QQuickContext2D::init(QQuickCanvasItem *canvasItem, const QVariantMap &args
     m_renderTarget = canvasItem->renderTarget();
 
     QQuickWindow *window = canvasItem->window();
-    m_windowManager =  QQuickWindowPrivate::get(window)->windowManager;
     m_renderStrategy = canvasItem->renderStrategy();
 
     switch (m_renderTarget) {
diff --git a/src/quick/items/context2d/qquickcontext2d_p.h b/src/quick/items/context2d/qquickcontext2d_p.h
index 2124c731b2..8d96ab579b 100644
--- a/src/quick/items/context2d/qquickcontext2d_p.h
+++ b/src/quick/items/context2d/qquickcontext2d_p.h
@@ -70,7 +70,6 @@ class QQuickContext2DCommandBuffer;
 class QQuickContext2DTexture;
 class QQuickPixmap;
 class QSGTexture;
-class QQuickWindowManager;
 class QSurface;
 class QOpenGLContext;
 
@@ -240,7 +239,6 @@ public:
     v8::Local<v8::Value> m_strokeStyle;
     v8::Handle<v8::Value> m_v8path;
     QV8Engine *m_v8engine;
-    QQuickWindowManager *m_windowManager;
     QSurface *m_surface;
     QOpenGLContext *m_glContext;
     v8::Persistent<v8::Object> m_v8value;
diff --git a/src/quick/items/items.pri b/src/quick/items/items.pri
index 13abf7b958..5272a3d5f7 100644
--- a/src/quick/items/items.pri
+++ b/src/quick/items/items.pri
@@ -74,9 +74,7 @@ HEADERS += \
     $$PWD/qquickitemview_p_p.h \
     $$PWD/qquickitemviewtransition_p.h \
     $$PWD/qquickscreen_p.h \
-    $$PWD/qquickwindowmodule_p.h \
-    $$PWD/qquickwindowmanager_p.h \
-    $$PWD/qquickthreadedwindowmanager_p.h
+    $$PWD/qquickwindowmodule_p.h
 
 SOURCES += \
     $$PWD/qquickevents.cpp \
@@ -128,9 +126,7 @@ SOURCES += \
     $$PWD/qquickitemview.cpp \
     $$PWD/qquickitemviewtransition.cpp \
     $$PWD/qquickwindowmodule.cpp \
-    $$PWD/qquickscreen.cpp \
-    $$PWD/qquickwindowmanager.cpp \
-    $$PWD/qquickthreadedwindowmanager.cpp
+    $$PWD/qquickscreen.cpp
 
 SOURCES += \
     $$PWD/qquickshadereffect.cpp \
diff --git a/src/quick/items/qquickthreadedwindowmanager.cpp b/src/quick/items/qquickthreadedwindowmanager.cpp
deleted file mode 100644
index 6c7b9c0448..0000000000
--- a/src/quick/items/qquickthreadedwindowmanager.cpp
+++ /dev/null
@@ -1,910 +0,0 @@
-/****************************************************************************
-**
-** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
-** Contact: http://www.qt-project.org/legal
-**
-** This file is part of the QtQml module of the Qt Toolkit.
-**
-** $QT_BEGIN_LICENSE:LGPL$
-** Commercial License Usage
-** Licensees holding valid commercial Qt licenses may use this file in
-** accordance with the commercial license agreement provided with the
-** Software or, alternatively, in accordance with the terms contained in
-** a written agreement between you and Digia.  For licensing terms and
-** conditions see http://qt.digia.com/licensing.  For further information
-** use the contact form at http://qt.digia.com/contact-us.
-**
-** GNU Lesser General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU Lesser
-** General Public License version 2.1 as published by the Free Software
-** Foundation and appearing in the file LICENSE.LGPL included in the
-** packaging of this file.  Please review the following information to
-** ensure the GNU Lesser General Public License version 2.1 requirements
-** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
-**
-** In addition, as a special exception, Digia gives you certain additional
-** rights.  These rights are described in the Digia Qt LGPL Exception
-** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
-**
-** GNU General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU
-** General Public License version 3.0 as published by the Free Software
-** Foundation and appearing in the file LICENSE.GPL included in the
-** packaging of this file.  Please review the following information to
-** ensure the GNU General Public License version 3.0 requirements will be
-** met: http://www.gnu.org/copyleft/gpl.html.
-**
-**
-** $QT_END_LICENSE$
-**
-****************************************************************************/
-
-#include "qquickwindowmanager_p.h"
-#include "qquickthreadedwindowmanager_p.h"
-
-#include <QtCore/QTime>
-#include <QtCore/QDebug>
-
-#include <QtGui/QOpenGLContext>
-#include <QtGui/private/qguiapplication_p.h>
-#include <qpa/qplatformintegration.h>
-
-#include <QtQml/private/qqmlglobal_p.h>
-
-#include <QtQuick/QQuickWindow>
-#include <QtQuick/private/qquickwindow_p.h>
-
-QT_BEGIN_NAMESPACE
-
-//#define THREAD_DEBUG
-extern Q_GUI_EXPORT QImage qt_gl_read_framebuffer(const QSize &size, bool alpha_format, bool include_alpha);
-
-const QEvent::Type QEvent_Sync = QEvent::Type(QEvent::User);
-const QEvent::Type QEvent_DeferredUpdate = QEvent::Type(QEvent::User + 1);
-
-#define QQUICK_RENDER_TIMING
-#ifdef QQUICK_RENDER_TIMING
-DEFINE_BOOL_CONFIG_OPTION(qquick_render_timing, QML_RENDER_TIMING)
-static QTime threadTimer;
-static int syncTime;
-static int renderTime;
-static int swapTime;
-#endif
-
-
-/*
-  Threaded Rendering
-  ==================
-
-  The threaded rendering uses a number of different variables to track potential
-  states used to handle resizing, initial paint, grabbing and driving animations
-  while ALWAYS keeping the GL context in the rendering thread and keeping the
-  overhead of normal one-shot paints and vblank driven animations at a minimum.
-
-  Resize, initial show and grab suffer slightly in this model as they are locked
-  to the rendering in the rendering thread, but this is a necessary evil for
-  the system to work.
-
-  Variables that are used:
-
-  Private::animationRunning: This is true while the animations are running, and only
-  written to inside locks.
-
-  RenderThread::isGuiLocked: This is used to indicate that the GUI thread owns the
-  lock. This variable is an integer to allow for recursive calls to lockInGui()
-  without using a recursive mutex. See isPostingSyncEvent.
-
-  RenderThread::isPostingSyncEvent: This variable is set in the render thread just
-  before the sync event is sent to the GUI thread. It is used to avoid deadlocks
-  in the case where render thread waits while waiting for GUI to pick up the sync
-  event and GUI thread gets a resizeEvent, the initial paintEvent or a grab.
-  When this happens, we use the
-  exhaustSyncEvent() function to do the sync right there and mark the coming
-  sync event to be discarded. There can only ever be one sync incoming.
-
-  RenderThread::isRenderBlock: This variable is true when animations are not
-  running and the render thread has gone to sleep, waiting for more to do.
-
-  RenderThread::isExternalUpdatePending: This variable is set to false when
-  a new render pass is started and to true in maybeUpdate(). It is an
-  indication to the render thread that another render pass needs to take
-  place, rather than the render thread going to sleep after completing its swap.
-
-  RenderThread::doGrab: This variable is set by the grab() function and
-  tells the renderer to do a grab after rendering is complete and before
-  swapping happens.
-
-  RenderThread::shouldExit: This variable is used to determine if the render
-  thread should do a nother pass. It is typically set as a result of show()
-  and unset as a result of hide() or during shutdown()
-
-  RenderThread::hasExited: Used by the GUI thread to synchronize the shutdown
-  after shouldExit has been set to true.
- */
-
-
-void QQuickRenderThreadSingleContextWindowManager::initialize()
-{
-    Q_ASSERT(m_rendered_windows.size());
-
-    QQuickWindow *win = 0;
-    for (QHash<QQuickWindow *, WindowData *>::const_iterator it = m_rendered_windows.constBegin();
-        it != m_rendered_windows.constEnd() && !win; ++it) {
-        if (QQuickWindowPrivate::get(it.key())->isRenderable())
-            win = it.key();
-    }
-    if (!win)
-        return;
-
-    gl = new QOpenGLContext();
-    // Pick up the surface format from one of them
-    gl->setFormat(win->requestedFormat());
-    gl->create();
-    if (!gl->makeCurrent(win))
-        qWarning("QQuickWindow: makeCurrent() failed...");
-
-    Q_ASSERT(!sg->isReady());
-    sg->initialize(gl);
-}
-
-
-/*!
-    This function is called when the window is created to register the window with
-    the window manager.
-
-    Called on GUI Thread.
- */
-
-void QQuickRenderThreadSingleContextWindowManager::show(QQuickWindow *window)
-{
-#ifdef THREAD_DEBUG
-    printf("GUI: Window added to windowing system, %p, %dx%d\n", window, window->width(), window->height());
-#endif
-
-    WindowTracker tracker;
-    tracker.window = window;
-    tracker.isVisible = false;
-    tracker.toBeRemoved = false;
-    m_tracked_windows << tracker;
-
-    connect(window, SIGNAL(widthChanged(int)), this, SLOT(windowVisibilityChanged()), Qt::DirectConnection);
-    connect(window, SIGNAL(heightChanged(int)), this, SLOT(windowVisibilityChanged()), Qt::DirectConnection);
-
-    windowVisibilityChanged();
-}
-
-
-void QQuickRenderThreadSingleContextWindowManager::handleAddedWindow(QQuickWindow *window)
-{
-#ifdef THREAD_DEBUG
-    printf("                RenderThread: adding window: %p\n", window);
-#endif
-
-    WindowData *data = new WindowData;
-    data->sizeWasChanged = false;
-    data->windowSize = window->size();
-    data->isVisible = window->isVisible();
-    data->isRenderable = QQuickWindowPrivate::get(window)->isRenderable();
-    m_rendered_windows[window] = data;
-
-    isExternalUpdatePending = true;
-}
-
-
-/*!
-    Called on Render Thread
- */
-void QQuickRenderThreadSingleContextWindowManager::handleAddedWindows()
-{
-#ifdef THREAD_DEBUG
-    printf("                RenderThread: about to add %d\n", m_added_windows.size());
-#endif
-
-    while (m_added_windows.size()) {
-        QQuickWindow *window = m_added_windows.takeLast();
-        handleAddedWindow(window);
-    }
-}
-
-
-/*!
-    Called on the GUI Thread, from the window' destructor
- */
-
-void QQuickRenderThreadSingleContextWindowManager::windowDestroyed(QQuickWindow *window)
-{
-#ifdef THREAD_DEBUG
-    printf("GUI: Window destroyed: %p\n", window);
-#endif
-
-    hide(window);
-}
-
-
-/*!
-    Called on GUI Thread
- */
-
-void QQuickRenderThreadSingleContextWindowManager::hide(QQuickWindow *window)
-{
-#ifdef THREAD_DEBUG
-    printf("GUI: Window hidden: %p\n", window);
-#endif
-
-    int position = -1;
-    for (int i=0; i<m_tracked_windows.size(); ++i) {
-        if (m_tracked_windows.at(i).window == window) {
-            m_tracked_windows[i].toBeRemoved = true;
-            position = i;
-            break;
-        }
-    }
-
-    if (position >= 0) {
-        disconnect(window, SIGNAL(widthChanged(int)), this, SLOT(windowVisibilityChanged()));
-        disconnect(window, SIGNAL(heightChanged(int)), this, SLOT(windowVisibilityChanged()));
-        windowVisibilityChanged();
-        m_tracked_windows.removeAt(position);
-    }
-
-#ifdef THREAD_DEBUG
-    printf("GUI: Window removal completed... %p\n", window);
-#endif
-}
-
-/*!
-    Called on Render Thread
- */
-void QQuickRenderThreadSingleContextWindowManager::handleRemovedWindows(bool clearGLContext)
-{
-#ifdef THREAD_DEBUG
-    printf("                RenderThread: about to remove %d\n", m_removed_windows.size());
-#endif
-
-    bool removedAnything = false;
-    while (m_removed_windows.size()) {
-        QQuickWindow *window = m_removed_windows.takeLast();
-#ifdef THREAD_DEBUG
-    printf("                RenderThread: removing %p\n", window);
-#endif
-
-        QQuickWindowPrivate::get(window)->cleanupNodesOnShutdown();
-        delete m_rendered_windows.take(window);
-        removedAnything = true;
-    }
-
-    // If a window is removed because it has been hidden it will take with it
-    // the gl context (at least on Mac) if bound, so disconnect the gl context
-    // from anything
-    if (removedAnything && clearGLContext)
-        gl->doneCurrent();
-}
-
-
-
-/*!
-    Called on GUI Thread
- */
-
-void QQuickRenderThreadSingleContextWindowManager::windowVisibilityChanged()
-{
-    bool anyoneShowing = false;
-    QList<QQuickWindow *> toAdd, toRemove;
-
-    // Not optimal, but also not frequently used...
-    for (int i=0; i<m_tracked_windows.size(); ++i) {
-        WindowTracker &t = const_cast<WindowTracker &>(m_tracked_windows.at(i));
-        QQuickWindow *win = t.window;
-
-        Q_ASSERT(win->isVisible() || QQuickWindowPrivate::get(win)->renderWithoutShowing || t.toBeRemoved);
-        bool windowVisible = win->width() > 0 && win->height() > 0;
-        anyoneShowing |= (windowVisible && !t.toBeRemoved);
-
-        if ((!windowVisible && t.isVisible) || t.toBeRemoved) {
-            toRemove << win;
-        } else if (windowVisible && !t.isVisible) {
-            toAdd << win;
-        }
-        t.isVisible = windowVisible;
-    }
-
-    if (isRunning()) {
-        if (!anyoneShowing) {
-            stopRendering();
-        } else {
-            lockInGui();
-            exhaustSyncEvent();
-            m_added_windows << toAdd;
-            m_removed_windows << toRemove;
-            while (isRunning() && (m_added_windows.size() || m_removed_windows.size())) {
-                if (isRenderBlocked)
-                    wake();
-                wait();
-            }
-            unlockInGui();
-        }
-
-    } else if (anyoneShowing) {
-        Q_ASSERT(toRemove.isEmpty()); // since loop is not running, nothing is showing now
-        for (int i=0; i<toAdd.size(); ++i)
-            handleAddedWindow(toAdd.at(i));
-        startRendering();
-    }
-
-}
-
-
-void QQuickRenderThreadSingleContextWindowManager::run()
-{
-#ifdef THREAD_DEBUG
-    printf("QML Rendering Thread Started\n");
-#endif
-
-    lock();
-    Q_ASSERT(!gl);
-    initialize();
-    // Wake GUI as it is waiting for the GL context to have appeared, as
-    // an indication that the render thread is now running.
-    wake();
-    unlock();
-
-    if (!gl)
-        return;
-
-    while (!shouldExit) {
-        lock();
-
-#ifdef THREAD_DEBUG
-        printf("                RenderThread: *** NEW FRAME ***\n");
-#endif
-
-        isExternalUpdatePending = false;
-        handleAddedWindows();
-
-        if (!isGuiLocked) {
-            isPostingSyncEvent = true;
-
-#ifdef THREAD_DEBUG
-            printf("                RenderThread: acquired sync lock...\n");
-#endif
-            QCoreApplication::postEvent(this, new QEvent(QEvent_Sync));
-
-#ifdef THREAD_DEBUG
-            printf("                RenderThread: going to sleep...\n");
-#endif
-            wake(); // In case the event got through all the way to wait() before this thread got to wait.
-            wait();
-
-
-            isPostingSyncEvent = false;
-        }
-
-#ifdef THREAD_DEBUG
-        printf("                RenderThread: Doing locked sync\n");
-#endif
-#ifdef QQUICK_RENDER_TIMING
-        if (qquick_render_timing())
-            threadTimer.start();
-#endif
-        inSync = true;
-        for (QHash<QQuickWindow *, WindowData *>::const_iterator it = m_rendered_windows.constBegin();
-             it != m_rendered_windows.constEnd(); ++it) {
-            QQuickWindow *window = it.key();
-
-#ifdef THREAD_DEBUG
-            printf("                RenderThread: Syncing window: %p\n", window);
-#endif
-
-            WindowData *windowData = it.value();
-            QQuickWindowPrivate *windowPrivate = QQuickWindowPrivate::get(window);
-
-            windowData->isRenderable = windowPrivate->isRenderable();
-
-            if (windowData->isRenderable) {
-                gl->makeCurrent(window);
-
-                if (windowData->viewportSize != windowData->windowSize) {
-#ifdef THREAD_DEBUG
-                    printf("                RenderThread: --- window has changed size...\n");
-#endif
-                    windowData->viewportSize = windowData->windowSize;
-                    windowData->sizeWasChanged = true;
-                    glViewport(0, 0, windowData->viewportSize.width(), windowData->viewportSize.height());
-                }
-
-                windowPrivate->syncSceneGraph();
-            }
-        }
-        inSync = false;
-
-        // Wake GUI after sync to let it continue animating and event processing.
-        wake();
-        unlock();
-#ifdef THREAD_DEBUG
-        printf("                RenderThread: sync done\n");
-#endif
-#ifdef QQUICK_RENDER_TIMING
-        if (qquick_render_timing())
-            syncTime = threadTimer.elapsed();
-#endif
-
-        for (QHash<QQuickWindow *, WindowData *>::const_iterator it = m_rendered_windows.constBegin();
-             it != m_rendered_windows.constEnd(); ++it) {
-            QQuickWindow *window = it.key();
-            WindowData *windowData = it.value();
-            QQuickWindowPrivate *windowPrivate = QQuickWindowPrivate::get(window);
-
-            if (!windowData->isRenderable)
-                continue;
-
-#ifdef THREAD_DEBUG
-            printf("                RenderThread: Rendering window %p\n", window);
-#endif
-
-            Q_ASSERT(windowData->windowSize.width() > 0 && windowData->windowSize.height() > 0);
-
-#ifdef THREAD_DEBUG
-            printf("                RenderThread: --- rendering at size %dx%d\n",
-                   windowData->viewportSize.width(), windowData->viewportSize.height()
-                   );
-#endif
-
-            // We only need to re-makeCurrent when we have multiple surfaces.
-            if (m_rendered_windows.size() > 1)
-                gl->makeCurrent(window);
-
-            windowPrivate->renderSceneGraph(windowData->viewportSize);
-#ifdef QQUICK_RENDER_TIMING
-            if (qquick_render_timing())
-                renderTime = threadTimer.elapsed() - syncTime;
-#endif
-
-            // The content of the target buffer is undefined after swap() so grab needs
-            // to happen before swap();
-            if (window == windowToGrab) {
-#ifdef THREAD_DEBUG
-                printf("                RenderThread: --- grabbing...\n");
-#endif
-                grabContent = qt_gl_read_framebuffer(windowData->windowSize, false, false);
-                windowToGrab = 0;
-            }
-
-#ifdef THREAD_DEBUG
-            printf("                RenderThread: --- wait for swap...\n");
-#endif
-
-            if (windowData->isVisible && window->isExposed())
-                gl->swapBuffers(window);
-
-            windowPrivate->fireFrameSwapped();
-#ifdef THREAD_DEBUG
-            printf("                RenderThread: --- swap complete...\n");
-#endif
-
-        }
-
-#ifdef QQUICK_RENDER_TIMING
-            if (qquick_render_timing()) {
-                static QTime lastFrameTime = QTime::currentTime();
-                swapTime = threadTimer.elapsed() - renderTime - syncTime;
-                qDebug() << "- Breakdown of frame time; sync:" << syncTime
-                         << "ms render:" << renderTime << "ms swap:" << swapTime
-                         << "ms total:" << swapTime + renderTime + syncTime
-                         << "ms time since last frame:" << (lastFrameTime.msecsTo(QTime::currentTime()))
-                         << "ms";
-                lastFrameTime = QTime::currentTime();
-            }
-#endif
-
-        lock();
-
-        handleRemovedWindows();
-
-        // Update sizes...
-        for (QHash<QQuickWindow *, WindowData *>::const_iterator it = m_rendered_windows.constBegin();
-             it != m_rendered_windows.constEnd(); ++it) {
-            WindowData *windowData = it.value();
-            if (windowData->sizeWasChanged) {
-                windowData->renderedSize = windowData->viewportSize;
-                windowData->sizeWasChanged = false;
-            }
-        }
-
-
-        // Wake the GUI thread now that rendering is complete, to signal that painting
-        // is done, resizing is done or grabbing is completed. For grabbing, we're
-        // signalling this much later than needed (we could have done it before swap)
-        // but we don't want to lock an extra time.
-        wake();
-
-        if (!animationRunning && !isExternalUpdatePending && !shouldExit && !windowToGrab) {
-#ifdef THREAD_DEBUG
-            printf("                RenderThread: nothing to do, going to sleep...\n");
-#endif
-            isRenderBlocked = true;
-            wait();
-            isRenderBlocked = false;
-        }
-
-        unlock();
-
-        QCoreApplication::processEvents();
-
-        // Process any "deleteLater" objects...
-        QCoreApplication::sendPostedEvents(0, QEvent::DeferredDelete);
-    }
-
-#ifdef THREAD_DEBUG
-    printf("                RenderThread: deleting all outstanding nodes\n");
-#endif
-
-    m_removed_windows << m_rendered_windows.keys();
-    handleRemovedWindows(false);
-
-    sg->invalidate();
-
-    gl->doneCurrent();
-    delete gl;
-    gl = 0;
-
-#ifdef THREAD_DEBUG
-    printf("                RenderThread: render loop exited... Good Night!\n");
-#endif
-
-    lock();
-    hasExited = true;
-
-#ifdef THREAD_DEBUG
-    printf("                RenderThread: waking GUI for final sleep..\n");
-#endif
-    wake();
-    unlock();
-
-#ifdef THREAD_DEBUG
-    printf("                RenderThread: All done...\n");
-#endif
-}
-
-bool QQuickRenderThreadSingleContextWindowManager::event(QEvent *e)
-{
-    Q_ASSERT(QThread::currentThread() == qApp->thread());
-
-    if (e->type() == QEvent_Sync) {
-
-        // If all windowes have been hidden, ignore the event
-        if (!isRunning())
-            return true;
-
-        if (!syncAlreadyHappened)
-            sync(false);
-
-        syncAlreadyHappened = false;
-
-        if (animationRunning) {
-#ifdef THREAD_DEBUG
-            printf("GUI: Advancing animations...\n");
-#endif
-
-            animDriver->advance();
-
-#ifdef THREAD_DEBUG
-            printf("GUI: Animations advanced...\n");
-#endif
-        }
-
-        return true;
-    } else if (e->type() == QEvent_DeferredUpdate) {
-        handleDeferredUpdate();
-
-    } else if (e->type() == QEvent::Timer) {
-#ifdef THREAD_DEBUG
-            printf("GUI: Animations advanced via timer...\n");
-#endif
-        animDriver->advance();
-    }
-
-    return QThread::event(e);
-}
-
-
-
-void QQuickRenderThreadSingleContextWindowManager::exhaustSyncEvent()
-{
-    if (isPostingSyncEvent) {
-        sync(true);
-        syncAlreadyHappened = true;
-    }
-}
-
-
-
-void QQuickRenderThreadSingleContextWindowManager::sync(bool guiAlreadyLocked)
-{
-#ifdef THREAD_DEBUG
-    printf("GUI: sync - %s\n", guiAlreadyLocked ? "outside event" : "inside event");
-#endif
-    if (!guiAlreadyLocked)
-        lockInGui();
-
-    for (QHash<QQuickWindow *, WindowData *>::const_iterator it = m_rendered_windows.constBegin();
-         it != m_rendered_windows.constEnd(); ++it) {
-        QQuickWindowPrivate::get(it.key())->polishItems();
-    }
-
-    wake();
-    wait();
-
-    if (!guiAlreadyLocked)
-        unlockInGui();
-}
-
-
-
-
-/*!
-    Acquires the mutex for the GUI thread. The function uses the isGuiLocked
-    variable to keep track of how many recursion levels the gui is locked with.
-    We only actually acquire the mutex for the first level to avoid deadlocking
-    ourselves.
- */
-
-void QQuickRenderThreadSingleContextWindowManager::lockInGui()
-{
-    if (++isGuiLocked == 1)
-        lock();
-
-#ifdef THREAD_DEBUG
-    printf("GUI: acquired lock... level=%d\n", isGuiLocked);
-#endif
-}
-
-
-
-void QQuickRenderThreadSingleContextWindowManager::unlockInGui()
-{
-#ifdef THREAD_DEBUG
-    printf("GUI: releasing lock... level=%d\n", isGuiLocked);
-#endif
-
-    if (--isGuiLocked == 0)
-        unlock();
-}
-
-
-
-
-void QQuickRenderThreadSingleContextWindowManager::animationStarted()
-{
-#ifdef THREAD_DEBUG
-    printf("GUI: animationStarted()\n");
-#endif
-
-    if (!isRunning()) {
-        animationTimer = startTimer(1000/60);
-        return;
-    }
-
-    lockInGui();
-
-    animationRunning = true;
-
-    if (isRenderBlocked)
-        wake();
-
-    unlockInGui();
-}
-
-
-
-void QQuickRenderThreadSingleContextWindowManager::animationStopped()
-{
-#ifdef THREAD_DEBUG
-    printf("GUI: animationStopped()...\n");
-#endif
-
-    if (!isRunning()) {
-        killTimer(animationTimer);
-        animationTimer = -1;
-        return;
-    }
-
-    lockInGui();
-    animationRunning = false;
-    unlockInGui();
-}
-
-
-void QQuickRenderThreadSingleContextWindowManager::exposureChanged(QQuickWindow *window)
-{
-    Q_UNUSED(window);
-#ifdef THREAD_DEBUG
-    printf("GUI: exposure changed: %p\n", window);
-#endif
-
-    if (window->isExposed())
-        maybeUpdate(window);
-
-#ifdef THREAD_DEBUG
-    printf("GUI: exposure changed done: %p\n", window);
-#endif
-}
-
-
-
-void QQuickRenderThreadSingleContextWindowManager::resize(QQuickWindow *window, const QSize &size)
-{
-#ifdef THREAD_DEBUG
-    printf("GUI: Resize Event: %p = %dx%d\n", window, size.width(), size.height());
-#endif
-
-    // If the rendering thread is not running we do not need to do anything.
-    // Also if the window is being resized to an invalid size, it will be removed
-    // by the windowVisibilityChanged slot as result of width/heightcChanged()
-    if (!isRunning() || size.width() <= 0 || size.height() <= 0)
-        return;
-
-    lockInGui();
-    exhaustSyncEvent();
-
-    WindowData *windowData = m_rendered_windows.value(window);
-    if (windowData) {
-        windowData->windowSize = size;
-        while (isRunning() && windowData->renderedSize != size && size.width() > 0 && size.height() > 0) {
-            if (isRenderBlocked)
-                wake();
-            wait();
-        }
-    }
-    unlockInGui();
-
-#ifdef THREAD_DEBUG
-    printf("GUI: Resize done: %p\n", window);
-#endif
-}
-
-
-
-void QQuickRenderThreadSingleContextWindowManager::startRendering()
-{
-#ifdef THREAD_DEBUG
-    printf("GUI: Starting Render Thread\n");
-#endif
-    hasExited = false;
-    shouldExit = false;
-    isGuiLocked = 0;
-    isPostingSyncEvent = false;
-    syncAlreadyHappened = false;
-    inSync = false;
-
-    lockInGui();
-    animationRunning = animDriver->isRunning();
-    start(); // Start the render thread...
-    wait();
-    unlockInGui();
-
-    // Animations will now be driven from the rendering thread.
-    if (animationTimer >= 0) {
-        killTimer(animationTimer);
-        animationTimer = -1;
-    }
-
-
-}
-
-
-
-void QQuickRenderThreadSingleContextWindowManager::stopRendering()
-{
-#ifdef THREAD_DEBUG
-    printf("GUI: stopping render thread\n");
-#endif
-
-    lockInGui();
-    exhaustSyncEvent();
-    shouldExit = true;
-
-    if (isRenderBlocked) {
-#ifdef THREAD_DEBUG
-        printf("GUI: waking up render thread\n");
-#endif
-        wake();
-    }
-
-    while (!hasExited) {
-#ifdef THREAD_DEBUG
-        printf("GUI: waiting for render thread to have exited..\n");
-#endif
-        wait();
-    }
-
-    unlockInGui();
-
-#ifdef THREAD_DEBUG
-    printf("GUI: waiting for render thread to terminate..\n");
-#endif
-    // Actually wait for the thread to terminate.  Otherwise we can delete it
-    // too early and crash.
-    QThread::wait();
-
-#ifdef THREAD_DEBUG
-    printf("GUI: thread has terminated and we're all good..\n");
-#endif
-
-    // Activate timer to keep animations running
-    if (animDriver->isRunning())
-        animationTimer = startTimer(1000/60);
-}
-
-
-
-QImage QQuickRenderThreadSingleContextWindowManager::grab(QQuickWindow *window)
-{
-    if (!isRunning())
-        return QImage();
-
-    if (QThread::currentThread() != qApp->thread()) {
-        qWarning("QQuickWindow::grabFrameBuffer: can only be called from the GUI thread");
-        return QImage();
-    } else if (window->size().width() <= 0 || window->size().height() <= 0 ) {
-        qWarning("QQuickWindow::grabFrameBuffer: Can't grab a Window with size %dx%d", window->size().width(), window->size().height());
-        return QImage();
-    }
-
-#ifdef THREAD_DEBUG
-    printf("GUI: doing a pixelwise grab..\n");
-#endif
-
-    lockInGui();
-    exhaustSyncEvent();
-
-    windowToGrab = window;
-    while (isRunning() && windowToGrab) {
-        if (isRenderBlocked)
-            wake();
-        wait();
-    }
-
-    QImage grabbed = grabContent;
-    grabContent = QImage();
-
-    unlockInGui();
-
-    return grabbed;
-}
-
-
-void QQuickRenderThreadSingleContextWindowManager::handleDeferredUpdate()
-{
-#ifdef THREAD_DEBUG
-    printf("GUI: handling update to ourselves...\n");
-#endif
-
-    isDeferredUpdatePosted = false;
-
-    lockInGui();
-    isExternalUpdatePending = true;
-    if (isRenderBlocked)
-        wake();
-    unlockInGui();
-}
-
-void QQuickRenderThreadSingleContextWindowManager::maybeUpdate(QQuickWindow *)
-{
-    Q_ASSERT_X(QThread::currentThread() == QCoreApplication::instance()->thread() || inSync,
-               "QQuickWindow::update",
-               "Function can only be called from GUI thread or during QQuickItem::updatePaintNode()");
-
-    if (inSync) {
-        isExternalUpdatePending = true;
-
-    } else if (!isDeferredUpdatePosted) {
-#ifdef THREAD_DEBUG
-        printf("GUI: posting update to ourselves...\n");
-#endif
-        isDeferredUpdatePosted = true;
-        QCoreApplication::postEvent(this, new QEvent(QEvent_DeferredUpdate));
-    }
-
-}
-
-QT_END_NAMESPACE
diff --git a/src/quick/items/qquickthreadedwindowmanager_p.h b/src/quick/items/qquickthreadedwindowmanager_p.h
deleted file mode 100644
index 76325e2d4f..0000000000
--- a/src/quick/items/qquickthreadedwindowmanager_p.h
+++ /dev/null
@@ -1,181 +0,0 @@
-/****************************************************************************
-**
-** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
-** Contact: http://www.qt-project.org/legal
-**
-** This file is part of the QtQml module of the Qt Toolkit.
-**
-** $QT_BEGIN_LICENSE:LGPL$
-** Commercial License Usage
-** Licensees holding valid commercial Qt licenses may use this file in
-** accordance with the commercial license agreement provided with the
-** Software or, alternatively, in accordance with the terms contained in
-** a written agreement between you and Digia.  For licensing terms and
-** conditions see http://qt.digia.com/licensing.  For further information
-** use the contact form at http://qt.digia.com/contact-us.
-**
-** GNU Lesser General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU Lesser
-** General Public License version 2.1 as published by the Free Software
-** Foundation and appearing in the file LICENSE.LGPL included in the
-** packaging of this file.  Please review the following information to
-** ensure the GNU Lesser General Public License version 2.1 requirements
-** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
-**
-** In addition, as a special exception, Digia gives you certain additional
-** rights.  These rights are described in the Digia Qt LGPL Exception
-** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
-**
-** GNU General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU
-** General Public License version 3.0 as published by the Free Software
-** Foundation and appearing in the file LICENSE.GPL included in the
-** packaging of this file.  Please review the following information to
-** ensure the GNU General Public License version 3.0 requirements will be
-** met: http://www.gnu.org/copyleft/gpl.html.
-**
-**
-** $QT_END_LICENSE$
-**
-****************************************************************************/
-
-#ifndef QQUICKTHREADEDWINDOWMANAGER_P_H
-#define QQUICKTHREADEDWINDOWMANAGER_P_H
-
-#include "qquickwindowmanager_p.h"
-
-#include <QtCore/QCoreApplication>
-#include <QtCore/QMutex>
-#include <QtCore/QWaitCondition>
-#include <QtCore/private/qabstractanimation_p.h>
-
-#include <QtGui/QOpenGLContext>
-#include <QtQuick/private/qsgcontext_p.h>
-#include <private/qtquickglobal_p.h>
-
-QT_BEGIN_NAMESPACE
-
-class QQuickRenderThreadSingleContextWindowManager : public QThread, public QQuickWindowManager
-{
-    Q_OBJECT
-public:
-    QQuickRenderThreadSingleContextWindowManager()
-        : sg(QSGContext::createDefaultContext())
-        , gl(0)
-        , animationTimer(-1)
-        , isGuiLocked(0)
-        , animationRunning(false)
-        , isPostingSyncEvent(false)
-        , isRenderBlocked(false)
-        , isExternalUpdatePending(false)
-        , syncAlreadyHappened(false)
-        , inSync(false)
-        , shouldExit(false)
-        , hasExited(false)
-        , isDeferredUpdatePosted(false)
-        , windowToGrab(0)
-    {
-        sg->moveToThread(this);
-
-        animDriver = sg->createAnimationDriver(this);
-        animDriver->install();
-        connect(animDriver, SIGNAL(started()), this, SLOT(animationStarted()));
-        connect(animDriver, SIGNAL(stopped()), this, SLOT(animationStopped()));
-    }
-
-    QSGContext *sceneGraphContext() const { return sg; }
-
-    void releaseResources() { }
-
-    void show(QQuickWindow *window);
-    void hide(QQuickWindow *window);
-
-    void windowDestroyed(QQuickWindow *window);
-
-    void exposureChanged(QQuickWindow *window);
-    QImage grab(QQuickWindow *window);
-    void resize(QQuickWindow *window, const QSize &size);
-    void handleDeferredUpdate();
-    void maybeUpdate(QQuickWindow *window);
-    void update(QQuickWindow *window) { maybeUpdate(window); } // identical for this implementation
-
-    void startRendering();
-    void stopRendering();
-
-    void exhaustSyncEvent();
-    void sync(bool guiAlreadyLocked);
-
-    void initialize();
-
-    bool event(QEvent *);
-
-    inline void lock() { mutex.lock(); }
-    inline void unlock() { mutex.unlock(); }
-    inline void wait() { condition.wait(&mutex); }
-    inline void wake() { condition.wakeOne(); }
-    void lockInGui();
-    void unlockInGui();
-
-    void run();
-
-    QAnimationDriver *animationDriver() const { return animDriver; }
-
-public slots:
-    void animationStarted();
-    void animationStopped();
-    void windowVisibilityChanged();
-
-private:
-    void handleAddedWindows();
-    void handleAddedWindow(QQuickWindow *window);
-    void handleRemovedWindows(bool clearGLContext = true);
-
-    QSGContext *sg;
-    QOpenGLContext *gl;
-    QAnimationDriver *animDriver;
-    int animationTimer;
-
-    QMutex mutex;
-    QWaitCondition condition;
-
-    int isGuiLocked;
-    uint animationRunning: 1;
-    uint isPostingSyncEvent : 1;
-    uint isRenderBlocked : 1;
-    uint isExternalUpdatePending : 1;
-    uint syncAlreadyHappened : 1;
-    uint inSync : 1;
-    uint shouldExit : 1;
-    uint hasExited : 1;
-    uint isDeferredUpdatePosted : 1;
-
-    QQuickWindow *windowToGrab;
-    QImage grabContent;
-
-    struct WindowData {
-        QSize renderedSize;
-        QSize windowSize;
-        QSize viewportSize;
-
-        uint sizeWasChanged : 1;
-        uint isVisible : 1;
-        uint isRenderable : 1;
-    };
-
-    QHash<QQuickWindow *, WindowData *> m_rendered_windows;
-
-    struct WindowTracker {
-        QQuickWindow *window;
-        uint isVisible : 1;
-        uint toBeRemoved : 1;
-    };
-
-    QList<WindowTracker> m_tracked_windows;
-
-    QList<QQuickWindow *> m_removed_windows;
-    QList<QQuickWindow *> m_added_windows;
-};
-
-QT_END_NAMESPACE
-
-#endif // QQUICKTHREADEDWINDOWMANAGER_P_H
diff --git a/src/quick/items/qquickwindow.cpp b/src/quick/items/qquickwindow.cpp
index 1b76dd7390..bf82423ca9 100644
--- a/src/quick/items/qquickwindow.cpp
+++ b/src/quick/items/qquickwindow.cpp
@@ -50,7 +50,7 @@
 #include <QtQuick/private/qsgtexture_p.h>
 #include <QtQuick/private/qsgflashnode_p.h>
 
-#include <private/qquickwindowmanager_p.h>
+#include <private/qsgrenderloop_p.h>
 
 #include <private/qguiapplication_p.h>
 #include <QtGui/QInputMethod>
@@ -366,8 +366,8 @@ QQuickWindowPrivate::QQuickWindowPrivate()
     , windowManager(0)
     , clearColor(Qt::white)
     , clearBeforeRendering(true)
-    , persistentGLContext(false)
-    , persistentSceneGraph(false)
+    , persistentGLContext(true)
+    , persistentSceneGraph(true)
     , lastWheelEventAccepted(false)
     , renderTarget(0)
     , renderTargetId(0)
@@ -392,7 +392,7 @@ void QQuickWindowPrivate::init(QQuickWindow *c)
     contentItemPrivate->windowRefCount = 1;
     contentItemPrivate->flags |= QQuickItem::ItemIsFocusScope;
 
-    windowManager = QQuickWindowManager::instance();
+    windowManager = QSGRenderLoop::instance();
     context = windowManager->sceneGraphContext();
     q->setSurfaceType(QWindow::OpenGLSurface);
     q->setFormat(context->defaultSurfaceFormat());
@@ -923,6 +923,8 @@ QQuickWindow::QQuickWindow(QWindow *parent)
     d->init(this);
 }
 
+
+
 /*!
     \internal
 */
@@ -966,20 +968,32 @@ QQuickWindow::~QQuickWindow()
 void QQuickWindow::releaseResources()
 {
     Q_D(QQuickWindow);
-    d->windowManager->releaseResources();
+    d->windowManager->releaseResources(this);
     QQuickPixmap::purgeCache();
 }
 
 
 
 /*!
-    Sets whether the OpenGL context can be released as a part of a call to
-    releaseResources() to \a persistent.
+    Sets whether the OpenGL context can be released to \a
+    persistent. The default value is true.
+
+    The OpenGL context can be released to free up graphics resources
+    when the window is obscured, hidden or not rendering. When this
+    happens is implementation specific.
 
-    The OpenGL context might still be released when the user makes an explicit
-    call to hide().
+    The QOpenGLContext::aboutToBeDestroyed() signal is emitted from
+    the QQuickWindow::openglContext() when the OpenGL context is about
+    to be released.  The QQuickWindow::sceneGraphInitialized() signal
+    is emitted when a new OpenGL context is created for this
+    window. Make a Qt::DirectConnection to these signals to be
+    notified.
 
-    \sa setPersistentSceneGraph()
+    The OpenGL context is still released when the last QQuickWindow is
+    deleted.
+
+    \sa setPersistentSceneGraph(),
+    QOpenGLContext::aboutToBeDestroyed(), sceneGraphInitialized()
  */
 
 void QQuickWindow::setPersistentOpenGLContext(bool persistent)
@@ -989,9 +1003,13 @@ void QQuickWindow::setPersistentOpenGLContext(bool persistent)
 }
 
 
+
 /*!
-    Returns whether the OpenGL context can be released as a part of a call to
-    releaseResources().
+    Returns whether the OpenGL context can be released during the
+    lifetime of the QQuickWindow.
+
+    \note This is a hint. When and how this happens is implementation
+    specific.
  */
 
 bool QQuickWindow::isPersistentOpenGLContext() const
@@ -1003,13 +1021,24 @@ bool QQuickWindow::isPersistentOpenGLContext() const
 
 
 /*!
-    Sets whether the scene graph nodes and resources can be released as a
-    part of a call to releaseResources() to \a persistent.
+    Sets whether the scene graph nodes and resources can be released
+    to \a persistent.  The default value is true.
+
+    The scene graph nodes and resources can be released to free up
+    graphics resources when the window is obscured, hidden or not
+    rendering. When this happens is implementation specific.
 
-    The scene graph nodes and resources might still be released when the user
-    makes an explicit call to hide().
+    The QQuickWindow::sceneGraphInvalidated() signal is emitted when
+    cleanup occurs. The QQuickWindow::sceneGraphInitialized() signal
+    is emitted when a new scene graph is recreated for this
+    window. Make a Qt::DirectConnection to these signals to be
+    notified.
 
-    \sa setPersistentOpenGLContext()
+    The scene graph nodes and resources are still released when the
+    last QQuickWindow is deleted.
+
+    \sa setPersistentOpenGLContext(),
+    sceneGraphInvalidated(), sceneGraphInitialized()
  */
 
 void QQuickWindow::setPersistentSceneGraph(bool persistent)
@@ -1021,8 +1050,11 @@ void QQuickWindow::setPersistentSceneGraph(bool persistent)
 
 
 /*!
-    Returns whether the scene graph nodes and resources can be released as a part
-    of a call to releaseResources().
+    Returns whether the scene graph nodes and resources can be
+    released during the lifetime of this QQuickWindow.
+
+    \note This is a hint. When and how this happens is implementation
+    specific.
  */
 
 bool QQuickWindow::isPersistentSceneGraph() const
diff --git a/src/quick/items/qquickwindow_p.h b/src/quick/items/qquickwindow_p.h
index da2ae8284d..f272f30f8e 100644
--- a/src/quick/items/qquickwindow_p.h
+++ b/src/quick/items/qquickwindow_p.h
@@ -73,7 +73,7 @@ QT_BEGIN_NAMESPACE
 
 //Make it easy to identify and customize the root item if needed
 
-class QQuickWindowManager;
+class QSGRenderLoop;
 
 class QQuickRootItem : public QQuickItem
 {
@@ -200,7 +200,7 @@ public:
     QSGContext *context;
     QSGRenderer *renderer;
 
-    QQuickWindowManager *windowManager;
+    QSGRenderLoop *windowManager;
 
     QColor clearColor;
 
diff --git a/src/quick/scenegraph/qsgcontext_p.h b/src/quick/scenegraph/qsgcontext_p.h
index 1ae3ada3d8..cdc83d1dee 100644
--- a/src/quick/scenegraph/qsgcontext_p.h
+++ b/src/quick/scenegraph/qsgcontext_p.h
@@ -69,7 +69,7 @@ class QQuickWindow;
 class QSGTexture;
 class QSGMaterial;
 class QSGMaterialShader;
-class QQuickWindowManager;
+class QSGRenderLoop;
 
 class QOpenGLContext;
 class QOpenGLFramebufferObject;
@@ -127,7 +127,7 @@ public:
     virtual QAnimationDriver *createAnimationDriver(QObject *parent);
 
     static QQuickTextureFactory *createTextureFactoryFromImage(const QImage &image);
-    static QQuickWindowManager *createWindowManager();
+    static QSGRenderLoop *createWindowManager();
 
 
 public slots:
diff --git a/src/quick/scenegraph/qsgcontextplugin.cpp b/src/quick/scenegraph/qsgcontextplugin.cpp
index 76b4e63816..545762aa72 100644
--- a/src/quick/scenegraph/qsgcontextplugin.cpp
+++ b/src/quick/scenegraph/qsgcontextplugin.cpp
@@ -157,7 +157,7 @@ QQuickTextureFactory *QSGContext::createTextureFactoryFromImage(const QImage &im
     specific window manager.
  */
 
-QQuickWindowManager *QSGContext::createWindowManager()
+QSGRenderLoop *QSGContext::createWindowManager()
 {
     QSGAdaptionPluginData *plugin = contextFactory();
     if (plugin->factory)
diff --git a/src/quick/scenegraph/qsgcontextplugin_p.h b/src/quick/scenegraph/qsgcontextplugin_p.h
index 4e5be6edce..036bc69c66 100644
--- a/src/quick/scenegraph/qsgcontextplugin_p.h
+++ b/src/quick/scenegraph/qsgcontextplugin_p.h
@@ -53,14 +53,14 @@ QT_BEGIN_NAMESPACE
 
 class QSGContext;
 
-class QQuickWindowManager;
+class QSGRenderLoop;
 
 struct Q_QUICK_PRIVATE_EXPORT QSGContextFactoryInterface : public QFactoryInterface
 {
     virtual QSGContext *create(const QString &key) const = 0;
 
     virtual QQuickTextureFactory *createTextureFactoryFromImage(const QImage &image) = 0;
-    virtual QQuickWindowManager *createWindowManager() = 0;
+    virtual QSGRenderLoop *createWindowManager() = 0;
 };
 
 #define QSGContextFactoryInterface_iid \
@@ -79,7 +79,7 @@ public:
     virtual QSGContext *create(const QString &key) const = 0;
 
     virtual QQuickTextureFactory *createTextureFactoryFromImage(const QImage &) { return 0; }
-    virtual QQuickWindowManager *createWindowManager() { return 0; }
+    virtual QSGRenderLoop *createWindowManager() { return 0; }
 };
 
 QT_END_NAMESPACE
diff --git a/src/quick/items/qquickwindowmanager.cpp b/src/quick/scenegraph/qsgrenderloop.cpp
index 69aa63c278..9117b2cffa 100644
--- a/src/quick/items/qquickwindowmanager.cpp
+++ b/src/quick/scenegraph/qsgrenderloop.cpp
@@ -39,8 +39,8 @@
 **
 ****************************************************************************/
 
-#include "qquickwindowmanager_p.h"
-#include "qquickthreadedwindowmanager_p.h"
+#include "qsgrenderloop_p.h"
+#include "qsgthreadedrenderloop_p.h"
 
 #include <QtCore/QCoreApplication>
 #include <QtCore/QTime>
@@ -74,17 +74,17 @@ extern Q_GUI_EXPORT QImage qt_gl_read_framebuffer(const QSize &size, bool alpha_
 DEFINE_BOOL_CONFIG_OPTION(qmlNoThreadedRenderer, QML_BAD_GUI_RENDER_LOOP);
 DEFINE_BOOL_CONFIG_OPTION(qmlForceThreadedRenderer, QML_FORCE_THREADED_RENDERER); // Might trigger graphics driver threading bugs, use at own risk
 
-QQuickWindowManager *QQuickWindowManager::s_instance = 0;
+QSGRenderLoop *QSGRenderLoop::s_instance = 0;
 
-QQuickWindowManager::~QQuickWindowManager()
+QSGRenderLoop::~QSGRenderLoop()
 {
 }
 
-class QQuickTrivialWindowManager : public QObject, public QQuickWindowManager
+class QSGGuiThreadRenderLoop : public QObject, public QSGRenderLoop
 {
     Q_OBJECT
 public:
-    QQuickTrivialWindowManager();
+    QSGGuiThreadRenderLoop();
 
     void show(QQuickWindow *window);
     void hide(QQuickWindow *window);
@@ -100,7 +100,7 @@ public:
     void maybeUpdate(QQuickWindow *window);
     void update(QQuickWindow *window) { maybeUpdate(window); } // identical for this implementation.
 
-    void releaseResources() { }
+    void releaseResources(QQuickWindow *) { }
 
     QAnimationDriver *animationDriver() const { return 0; }
 
@@ -124,7 +124,7 @@ public:
 };
 
 
-QQuickWindowManager *QQuickWindowManager::instance()
+QSGRenderLoop *QSGRenderLoop::instance()
 {
     if (!s_instance) {
 
@@ -153,20 +153,20 @@ QQuickWindowManager *QQuickWindowManager::instance()
 
         if (!s_instance) {
             s_instance = fancy
-                    ? (QQuickWindowManager*) new QQuickRenderThreadSingleContextWindowManager
-                    : (QQuickWindowManager*) new QQuickTrivialWindowManager;
+                    ? (QSGRenderLoop*) new QSGThreadedRenderLoop
+                    : (QSGRenderLoop*) new QSGGuiThreadRenderLoop;
         }
     }
     return s_instance;
 }
 
-void QQuickWindowManager::setInstance(QQuickWindowManager *instance)
+void QSGRenderLoop::setInstance(QSGRenderLoop *instance)
 {
     Q_ASSERT(!s_instance);
     s_instance = instance;
 }
 
-QQuickTrivialWindowManager::QQuickTrivialWindowManager()
+QSGGuiThreadRenderLoop::QSGGuiThreadRenderLoop()
     : gl(0)
     , eventPending(false)
 {
@@ -174,7 +174,7 @@ QQuickTrivialWindowManager::QQuickTrivialWindowManager()
 }
 
 
-void QQuickTrivialWindowManager::show(QQuickWindow *window)
+void QSGGuiThreadRenderLoop::show(QQuickWindow *window)
 {
     WindowData data;
     data.updatePending = false;
@@ -184,7 +184,7 @@ void QQuickTrivialWindowManager::show(QQuickWindow *window)
     maybeUpdate(window);
 }
 
-void QQuickTrivialWindowManager::hide(QQuickWindow *window)
+void QSGGuiThreadRenderLoop::hide(QQuickWindow *window)
 {
     if (!m_windows.contains(window))
         return;
@@ -200,12 +200,12 @@ void QQuickTrivialWindowManager::hide(QQuickWindow *window)
     }
 }
 
-void QQuickTrivialWindowManager::windowDestroyed(QQuickWindow *window)
+void QSGGuiThreadRenderLoop::windowDestroyed(QQuickWindow *window)
 {
     hide(window);
 }
 
-void QQuickTrivialWindowManager::renderWindow(QQuickWindow *window)
+void QSGGuiThreadRenderLoop::renderWindow(QQuickWindow *window)
 {
     bool renderWithoutShowing = QQuickWindowPrivate::get(window)->renderWithoutShowing;
     if ((!window->isExposed() && !renderWithoutShowing) || !m_windows.contains(window))
@@ -294,13 +294,13 @@ void QQuickTrivialWindowManager::renderWindow(QQuickWindow *window)
         maybeUpdate(window);
 }
 
-void QQuickTrivialWindowManager::exposureChanged(QQuickWindow *window)
+void QSGGuiThreadRenderLoop::exposureChanged(QQuickWindow *window)
 {
     if (window->isExposed())
         maybeUpdate(window);
 }
 
-QImage QQuickTrivialWindowManager::grab(QQuickWindow *window)
+QImage QSGGuiThreadRenderLoop::grab(QQuickWindow *window)
 {
     if (!m_windows.contains(window))
         return QImage();
@@ -316,13 +316,13 @@ QImage QQuickTrivialWindowManager::grab(QQuickWindow *window)
 
 
 
-void QQuickTrivialWindowManager::resize(QQuickWindow *, const QSize &)
+void QSGGuiThreadRenderLoop::resize(QQuickWindow *, const QSize &)
 {
 }
 
 
 
-void QQuickTrivialWindowManager::maybeUpdate(QQuickWindow *window)
+void QSGGuiThreadRenderLoop::maybeUpdate(QQuickWindow *window)
 {
     if (!m_windows.contains(window))
         return;
@@ -337,13 +337,13 @@ void QQuickTrivialWindowManager::maybeUpdate(QQuickWindow *window)
 
 
 
-QSGContext *QQuickTrivialWindowManager::sceneGraphContext() const
+QSGContext *QSGGuiThreadRenderLoop::sceneGraphContext() const
 {
     return sg;
 }
 
 
-bool QQuickTrivialWindowManager::event(QEvent *e)
+bool QSGGuiThreadRenderLoop::event(QEvent *e)
 {
     if (e->type() == QEvent::User) {
         eventPending = false;
@@ -358,6 +358,6 @@ bool QQuickTrivialWindowManager::event(QEvent *e)
     return QObject::event(e);
 }
 
-#include "qquickwindowmanager.moc"
+#include "qsgrenderloop.moc"
 
 QT_END_NAMESPACE
diff --git a/src/quick/items/qquickwindowmanager_p.h b/src/quick/scenegraph/qsgrenderloop_p.h
index 94142a9d90..fc705f48e8 100644
--- a/src/quick/items/qquickwindowmanager_p.h
+++ b/src/quick/scenegraph/qsgrenderloop_p.h
@@ -39,22 +39,24 @@
 **
 ****************************************************************************/
 
-#ifndef QQUICKWINDOWMANAGER_P_H
-#define QQUICKWINDOWMANAGER_P_H
+#ifndef QSGRenderLoop_P_H
+#define QSGRenderLoop_P_H
 
 #include <QtGui/QImage>
 #include <private/qtquickglobal_p.h>
 
+QT_BEGIN_HEADER
+
 QT_BEGIN_NAMESPACE
 
 class QQuickWindow;
 class QSGContext;
 class QAnimationDriver;
 
-class Q_QUICK_PRIVATE_EXPORT QQuickWindowManager
+class Q_QUICK_PRIVATE_EXPORT QSGRenderLoop
 {
 public:
-    virtual ~QQuickWindowManager();
+    virtual ~QSGRenderLoop();
 
     virtual void show(QQuickWindow *window) = 0;
     virtual void hide(QQuickWindow *window) = 0;
@@ -72,16 +74,18 @@ public:
 
     virtual QSGContext *sceneGraphContext() const = 0;
 
-    virtual void releaseResources() = 0;
+    virtual void releaseResources(QQuickWindow *window) = 0;
 
     // ### make this less of a singleton
-    static QQuickWindowManager *instance();
-    static void setInstance(QQuickWindowManager *instance);
+    static QSGRenderLoop *instance();
+    static void setInstance(QSGRenderLoop *instance);
 
 private:
-    static QQuickWindowManager *s_instance;
+    static QSGRenderLoop *s_instance;
 };
 
 QT_END_NAMESPACE
 
-#endif // QQUICKWINDOWMANAGER_P_H
+QT_END_HEADER
+
+#endif // QSGRenderLoop_P_H
diff --git a/src/quick/scenegraph/qsgthreadedrenderloop.cpp b/src/quick/scenegraph/qsgthreadedrenderloop.cpp
new file mode 100644
index 0000000000..5ec6de2f04
--- /dev/null
+++ b/src/quick/scenegraph/qsgthreadedrenderloop.cpp
@@ -0,0 +1,1044 @@
+/****************************************************************************
+**
+** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and Digia.  For licensing terms and
+** conditions see http://qt.digia.com/licensing.  For further information
+** use the contact form at http://qt.digia.com/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Digia gives you certain additional
+** rights.  These rights are described in the Digia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3.0 as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU General Public License version 3.0 requirements will be
+** met: http://www.gnu.org/copyleft/gpl.html.
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+
+#include <QtCore/QMutex>
+#include <QtCore/QWaitCondition>
+#include <QtCore/QAnimationDriver>
+
+#include <QtGui/QGuiApplication>
+#include <QtGui/QScreen>
+
+#include <QtQuick/QQuickWindow>
+#include <private/qquickwindow_p.h>
+
+#include <QtQuick/private/qsgrenderer_p.h>
+
+#include "qsgthreadedrenderloop_p.h"
+
+/*
+   Overall design:
+
+   There are two classes here. QSGThreadedRenderLoop and
+   QSGRenderThread. All communication between the two is based on
+   event passing and we have a number of custom events.
+
+   In this implementation, the render thread is never blocked and the
+   GUI thread will initiate a polishAndSync which will block and wait
+   for the render thread to pick it up and release the block only
+   after the render thread is done syncing. The reason for this
+   is:
+
+   1. Clear blocking paradigm. We only have one real "block" point
+   (polishAndSync()) and all blocking is initiated by GUI and picked
+   up by Render at specific times based on events. This makes the
+   execution deterministic.
+
+   2. Render does not have to interact with GUI. This is done so that
+   the render thread can run its own animation system which stays
+   alive even when the GUI thread is blocked doing i/o, object
+   instantiation, QPainter-painting or any other non-trivial task.
+
+   ---
+
+   The render loop is active while any window is exposed. All visible
+   windows are tracked, but only exposed windows are actually added to
+   the render thread and rendered. That means that if all windows are
+   obscured, we might end up cleaning up the SG and GL context (if all
+   windows have disabled persistency). Especially for multiprocess,
+   low-end systems, this should be quite important.
+
+ */
+
+QT_BEGIN_NAMESPACE
+
+
+// #define QSG_RENDER_LOOP_DEBUG
+// #define QSG_RENDER_LOOP_DEBUG_FULL
+#ifdef QSG_RENDER_LOOP_DEBUG
+#define QSG_RENDER_LOOP_DEBUG_BASIC
+#endif
+
+#ifdef QSG_RENDER_LOOP_DEBUG_FULL
+#define QSG_RENDER_LOOP_DEBUG_BASIC
+#endif
+
+#if defined (QSG_RENDER_LOOP_DEBUG_FULL)
+#  define RLDEBUG1(x) qDebug("%s : %4d - %s", __FILE__, __LINE__, x);
+#  define RLDEBUG(x) qDebug("%s : %4d - %s", __FILE__, __LINE__, x);
+#elif defined (QSG_RENDER_LOOP_DEBUG_BASIC)
+#  define RLDEBUG1(x) qDebug("%s : %4d - %s", __FILE__, __LINE__, x);
+#  define RLDEBUG(x)
+#else
+#  define RLDEBUG1(x)
+#  define RLDEBUG(x)
+#endif
+
+
+static int get_env_int(const char *name, int defaultValue)
+{
+    QByteArray content = qgetenv(name);
+
+    bool ok = false;
+    int value = content.toInt(&ok);
+    return ok ? value : defaultValue;
+}
+
+
+static inline int qsgrl_animation_interval() {
+    qreal refreshRate = QGuiApplication::primaryScreen()->refreshRate();
+    // To work around that some platforms wrongfully return 0 or something
+    // bogus for refreshrate
+    if (refreshRate < 1)
+        return 16;
+    return int(1000 / refreshRate);
+}
+
+
+#define QQUICK_WINDOW_TIMING
+#ifdef QQUICK_WINDOW_TIMING
+static bool qquick_window_timing = !qgetenv("QML_WINDOW_TIMING").isEmpty();
+static QTime threadTimer;
+static int syncTime;
+static int renderTime;
+static int sinceLastTime;
+#endif
+
+extern Q_GUI_EXPORT QImage qt_gl_read_framebuffer(const QSize &size, bool alpha_format, bool include_alpha);
+
+// RL: Render Loop
+// RT: Render Thread
+
+// Passed from the RL to the RT when a window is rendeirng on screen
+// and should be added to the render loop.
+const QEvent::Type WM_Expose            = QEvent::Type(QEvent::User + 1);
+
+// Passed from the RL to the RT when a window is removed obscured and
+// should be removed from the render loop.
+const QEvent::Type WM_Obscure           = QEvent::Type(QEvent::User + 2);
+
+// Passed from the RL to itself to initiate a polishAndSync() call.
+const QEvent::Type WM_LockAndSync       = QEvent::Type(QEvent::User + 3);
+
+// Passed from the RL to RT when GUI has been locked, waiting for sync
+// (updatePaintNode())
+const QEvent::Type WM_RequestSync       = QEvent::Type(QEvent::User + 4);
+
+// Passed by the RT to itself to trigger another render pass. This is
+// typically a result of QQuickWindow::update().
+const QEvent::Type WM_RequestRepaint    = QEvent::Type(QEvent::User + 5);
+
+// Passed by the RL to the RT when a window has changed size.
+const QEvent::Type WM_Resize            = QEvent::Type(QEvent::User + 6);
+
+// Passed by the RL to the RT to free up maybe release SG and GL contexts
+// if no windows are rendering.
+const QEvent::Type WM_TryRelease        = QEvent::Type(QEvent::User + 7);
+
+// Passed by the RL to the RL when maybeUpdate is called on the RT to
+// just replay the maybeUpdate later. This typically happens when
+// updatePaintNode() results in a call to QQuickItem::update().
+const QEvent::Type WM_UpdateLater       = QEvent::Type(QEvent::User + 8);
+
+// Passed by the RL to the RT when a QQuickWindow::grabWindow() is
+// called.
+const QEvent::Type WM_Grab              = QEvent::Type(QEvent::User + 9);
+
+// Passed by the RT to the RL to trigger animations to be advanced.
+const QEvent::Type WM_AdvanceAnimations = QEvent::Type(QEvent::User + 10);
+
+template <typename T> T *windowFor(const QList<T> list, QQuickWindow *window)
+{
+    for (int i=0; i<list.size(); ++i) {
+        const T &t = list.at(i);
+        if (t.window == window)
+            return const_cast<T *>(&t);
+    }
+    return 0;
+}
+
+
+class WMWindowEvent : public QEvent
+{
+public:
+    WMWindowEvent(QQuickWindow *c, QEvent::Type type) : QEvent(type), window(c) { }
+    QQuickWindow *window;
+};
+
+class WMTryReleaseEvent : public WMWindowEvent
+{
+public:
+    WMTryReleaseEvent(QQuickWindow *win, bool destroy)
+        : WMWindowEvent(win, WM_TryRelease)
+        , inDestructor(destroy)
+    {}
+
+    bool inDestructor;
+};
+
+class WMResizeEvent : public WMWindowEvent
+{
+public:
+    WMResizeEvent(QQuickWindow *c, const QSize &s) : WMWindowEvent(c, WM_Resize), size(s) { }
+    QSize size;
+};
+
+
+class WMExposeEvent : public WMWindowEvent
+{
+public:
+    WMExposeEvent(QQuickWindow *c) : WMWindowEvent(c, WM_Expose), size(c->size()) { }
+    QSize size;
+};
+
+
+class WMGrabEvent : public WMWindowEvent
+{
+public:
+    WMGrabEvent(QQuickWindow *c, QImage *result) : WMWindowEvent(c, WM_Grab), image(result) {}
+    QImage *image;
+};
+
+
+class QSGRenderThread : public QThread
+{
+    Q_OBJECT
+public:
+
+    QSGRenderThread(QSGThreadedRenderLoop *w)
+        : wm(w)
+        , gl(0)
+        , sg(QSGContext::createDefaultContext())
+        , pendingUpdate(0)
+        , sleeping(false)
+        , animationRunning(false)
+        , guiIsLocked(false)
+        , shouldExit(false)
+        , allowMainThreadProcessing(true)
+        , animationRequestsPending(0)
+    {
+        sg->moveToThread(this);
+    }
+
+
+    void invalidateOpenGL(QQuickWindow *window, bool inDestructor);
+    void initializeOpenGL();
+
+    bool event(QEvent *);
+    void run();
+
+    void syncAndRender();
+    void sync();
+
+    void requestRepaint()
+    {
+        if (sleeping)
+            exit();
+        if (m_windows.size() > 0)
+            pendingUpdate |= RepaintRequest;
+    }
+
+public slots:
+    void animationStarted() {
+        RLDEBUG("    Render: animationStarted()");
+        animationRunning = true;
+        if (sleeping)
+            exit();
+    }
+
+    void animationStopped() {
+        RLDEBUG("    Render: animationStopped()");
+        animationRunning = false;
+    }
+
+public:
+    enum UpdateRequest {
+        SyncRequest         = 0x01,
+        RepaintRequest      = 0x02
+    };
+
+    QSGThreadedRenderLoop *wm;
+    QOpenGLContext *gl;
+    QSGContext *sg;
+
+    QEventLoop eventLoop;
+
+    uint pendingUpdate : 2;
+    uint sleeping : 1;
+    uint animationRunning : 1;
+
+    volatile bool guiIsLocked;
+    volatile bool shouldExit;
+
+    volatile bool allowMainThreadProcessing;
+    volatile int animationRequestsPending;
+
+    QMutex mutex;
+    QWaitCondition waitCondition;
+
+    QElapsedTimer m_timer;
+
+    struct Window {
+        QQuickWindow *window;
+        QSize size;
+    };
+    QList<Window> m_windows;
+};
+
+bool QSGRenderThread::event(QEvent *e)
+{
+    switch ((int) e->type()) {
+
+    case WM_Expose: {
+        RLDEBUG1("    Render: WM_Expose");
+        WMExposeEvent *se = static_cast<WMExposeEvent *>(e);
+
+        if (windowFor(m_windows, se->window)) {
+            RLDEBUG1("    Render:  - window already added...");
+            return true;
+        }
+
+        Window window;
+        window.window = se->window;
+        window.size = se->size;
+        m_windows << window;
+        return true; }
+
+    case WM_Obscure: {
+        RLDEBUG1("    Render: WM_Obscure");
+        WMWindowEvent *ce = static_cast<WMWindowEvent *>(e);
+        for (int i=0; i<m_windows.size(); ++i) {
+            if (m_windows.at(i).window == ce->window) {
+                RLDEBUG1("    Render:  - removed one...");
+                m_windows.removeAt(i);
+                break;
+            }
+        }
+
+        if (sleeping && m_windows.size())
+            exit();
+
+        return true; }
+
+    case WM_RequestSync:
+        RLDEBUG("    Render: WM_RequestSync");
+        if (sleeping)
+            exit();
+        if (m_windows.size() > 0)
+            pendingUpdate |= SyncRequest;
+        return true;
+
+    case WM_Resize: {
+        RLDEBUG("    Render: WM_Resize");
+        WMResizeEvent *re = static_cast<WMResizeEvent *>(e);
+        Window *w = windowFor(m_windows, re->window);
+        w->size = re->size;
+        // No need to wake up here as we will get a sync shortly.. (see QSGThreadedRenderLoop::resize());
+        return true; }
+
+    case WM_TryRelease:
+        RLDEBUG1("    Render: WM_TryRelease");
+        mutex.lock();
+        if (m_windows.size() == 0) {
+            WMTryReleaseEvent *wme = static_cast<WMTryReleaseEvent *>(e);
+            RLDEBUG1("    Render:  - setting exit flag and invalidating GL");
+            invalidateOpenGL(wme->window, wme->inDestructor);
+            shouldExit = !gl;
+            if (sleeping)
+                exit();
+        } else {
+            RLDEBUG1("    Render:  - not releasing anything because we have active windows...");
+        }
+        waitCondition.wakeOne();
+        mutex.unlock();
+        return true;
+
+    case WM_Grab: {
+        RLDEBUG1("    Render: WM_Grab");
+        WMGrabEvent *ce = static_cast<WMGrabEvent *>(e);
+        Window *w = windowFor(m_windows, ce->window);
+        mutex.lock();
+        if (w) {
+            gl->makeCurrent(ce->window);
+
+            RLDEBUG1("    Render: - syncing scene graph");
+            QQuickWindowPrivate *d = QQuickWindowPrivate::get(w->window);
+            d->syncSceneGraph();
+
+            RLDEBUG1("    Render: - rendering scene graph");
+            QQuickWindowPrivate::get(ce->window)->renderSceneGraph(w->size);
+
+            RLDEBUG1("    Render: - grabbing result...");
+            *ce->image = qt_gl_read_framebuffer(w->size, false, false);
+        }
+        RLDEBUG1("    Render:  - waking gui to handle grab result");
+        waitCondition.wakeOne();
+        mutex.unlock();
+        return true;
+    }
+
+    default:
+        break;
+    }
+    return QThread::event(e);
+}
+
+void QSGRenderThread::invalidateOpenGL(QQuickWindow *window, bool inDestructor)
+{
+    RLDEBUG1("    Render: invalidateOpenGL()");
+
+    if (!gl)
+        return;
+
+    if (!window) {
+        qWarning("QSGThreadedRenderLoop:QSGRenderThread: no window to make current...");
+        return;
+    }
+
+
+    bool persistentGL = false;
+    bool persistentSG = false;
+
+    // GUI is locked so accessing the wm and window here is safe
+    for (int i=0; i<wm->m_windows.size(); ++i) {
+        const QSGThreadedRenderLoop::Window &w = wm->m_windows.at(i);
+        if (!inDestructor || w.window != window) {
+            persistentSG |= w.window->isPersistentSceneGraph();
+            persistentGL |= w.window->isPersistentOpenGLContext();
+        }
+    }
+
+    gl->makeCurrent(window);
+
+    // The canvas nodes must be cleanded up regardless if we are in the destructor..
+    if (!persistentSG || inDestructor) {
+        QQuickWindowPrivate *dd = QQuickWindowPrivate::get(window);
+        dd->cleanupNodesOnShutdown();
+    }
+
+    // We're not doing any cleanup in this case...
+    if (persistentSG) {
+        RLDEBUG1("    Render:  - persistent SG, avoiding cleanup");
+        return;
+    }
+
+    sg->invalidate();
+    QCoreApplication::sendPostedEvents(0, QEvent::DeferredDelete);
+    gl->doneCurrent();
+    RLDEBUG1("    Render:  - invalidated scenegraph..");
+
+    if (!persistentGL) {
+        delete gl;
+        gl = 0;
+        RLDEBUG1("    Render:  - invalidated OpenGL");
+    } else {
+        RLDEBUG1("    Render:  - persistent GL, avoiding cleanup");
+    }
+}
+
+void QSGRenderThread::initializeOpenGL()
+{
+    RLDEBUG1("    Render: initializeOpenGL()");
+    QWindow *win = m_windows.at(0).window;
+    bool temp = false;
+
+    // Workaround for broken expose logic... We should not get an
+    // expose when the size of a window is invalid, but we sometimes do.
+    // On Mac this leads to harmless, yet annoying, console warnings
+    if (m_windows.at(0).size.isEmpty()) {
+        temp = true;
+        win = new QWindow();
+        win->setFormat(m_windows.at(0).window->requestedFormat());
+        win->setSurfaceType(QWindow::OpenGLSurface);
+        win->setGeometry(0, 0, 64, 64);
+        win->create();
+    }
+
+    gl = new QOpenGLContext();
+    // Pick up the surface format from one of them
+    gl->setFormat(win->requestedFormat());
+    gl->create();
+    if (!gl->makeCurrent(win))
+        qWarning("QQuickWindow: makeCurrent() failed...");
+    sg->initialize(gl);
+
+    if (temp) {
+        delete win;
+    }
+}
+
+/*!
+    Enters the mutex lock to make sure GUI is blocking and performs
+    sync, then wakes GUI.
+ */
+void QSGRenderThread::sync()
+{
+    RLDEBUG("    Render: sync()");
+    mutex.lock();
+
+    Q_ASSERT_X(guiIsLocked, "QSGRenderThread::sync()", "sync triggered on bad terms as gui is not already locked...");
+    pendingUpdate = 0;
+
+    for (int i=0; i<m_windows.size(); ++i) {
+        Window &w = const_cast<Window &>(m_windows.at(i));
+        if (w.size.width() == 0 || w.size.height() == 0) {
+            RLDEBUG("    Render:  - window has bad size, waiting...");
+            continue;
+        }
+        gl->makeCurrent(w.window);
+        QQuickWindowPrivate *d = QQuickWindowPrivate::get(w.window);
+        d->syncSceneGraph();
+    }
+
+    RLDEBUG("    Render:  - unlocking after sync");
+
+    waitCondition.wakeOne();
+    mutex.unlock();
+}
+
+
+void QSGRenderThread::syncAndRender()
+{
+#ifdef QQUICK_WINDOW_TIMING
+    if (qquick_window_timing)
+        sinceLastTime = threadTimer.restart();
+#endif
+    RLDEBUG("    Render: syncAndRender()");
+
+    // This animate request will get there after the sync
+    if (animationRunning && animationRequestsPending < 2) {
+        RLDEBUG("    Render:  - posting animate to gui..");
+        ++animationRequestsPending;
+        QCoreApplication::postEvent(wm, new QEvent(WM_AdvanceAnimations));
+
+    }
+
+    if (pendingUpdate & SyncRequest) {
+        RLDEBUG("    Render:  - update pending, doing sync");
+        sync();
+    }
+
+#ifdef QQUICK_WINDOW_TIMING
+    if (qquick_window_timing)
+        syncTime = threadTimer.elapsed();
+#endif
+
+    for (int i=0; i<m_windows.size(); ++i) {
+        Window &w = const_cast<Window &>(m_windows.at(i));
+        QQuickWindowPrivate *d = QQuickWindowPrivate::get(w.window);
+        if (!d->renderer || w.size.width() == 0 || w.size.height() == 0) {
+            RLDEBUG("    Render:  - Window not yet ready, skipping render...");
+            continue;
+        }
+        gl->makeCurrent(w.window);
+        d->renderSceneGraph(w.size);
+#ifdef QQUICK_WINDOW_TIMING
+        if (qquick_window_timing && i == 0)
+            renderTime = threadTimer.elapsed();
+#endif
+        gl->swapBuffers(w.window);
+        d->fireFrameSwapped();
+    }
+    RLDEBUG("    Render:  - rendering done");
+
+#ifdef QQUICK_WINDOW_TIMING
+        if (qquick_window_timing)
+            qDebug("window Time: sinceLast=%d, sync=%d, first render=%d, after final swap=%d",
+                   sinceLastTime,
+                   syncTime,
+                   renderTime - syncTime,
+                   threadTimer.elapsed() - renderTime);
+#endif
+}
+
+void QSGRenderThread::run()
+{
+    RLDEBUG1("    Render: run()");
+    while (!shouldExit) {
+
+        if (m_windows.size() > 0) {
+            if (!gl)
+                initializeOpenGL();
+            if (!sg->isReady())
+                sg->initialize(gl);
+            syncAndRender();
+        }
+
+        QCoreApplication::processEvents();
+        QCoreApplication::sendPostedEvents(0, QEvent::DeferredDelete);
+
+        if (!shouldExit
+            && ((!animationRunning && pendingUpdate == 0) || m_windows.size() == 0)) {
+            RLDEBUG("    Render: enter event loop (going to sleep)");
+            sleeping = true;
+            exec();
+            sleeping = false;
+        }
+
+    }
+
+    Q_ASSERT_X(!gl, "QSGRenderThread::run()", "The OpenGL context should be cleaned up before exiting the render thread...");
+
+    RLDEBUG1("    Render: run() completed...");
+}
+
+QSGThreadedRenderLoop::QSGThreadedRenderLoop()
+    : m_animation_timer(0)
+    , m_update_timer(0)
+{
+    m_thread = new QSGRenderThread(this);
+    m_thread->moveToThread(m_thread);
+
+    m_animation_driver = m_thread->sg->createAnimationDriver(this);
+
+    m_exhaust_delay = get_env_int("QML_EXHAUST_DELAY", 5);
+
+    connect(m_animation_driver, SIGNAL(started()), m_thread, SLOT(animationStarted()));
+    connect(m_animation_driver, SIGNAL(stopped()), m_thread, SLOT(animationStopped()));
+    connect(m_animation_driver, SIGNAL(started()), this, SLOT(animationStarted()));
+    connect(m_animation_driver, SIGNAL(stopped()), this, SLOT(animationStopped()));
+
+    m_animation_driver->install();
+    RLDEBUG1("GUI: QSGThreadedRenderLoop() created");
+}
+
+QAnimationDriver *QSGThreadedRenderLoop::animationDriver() const
+{
+    return m_animation_driver;
+}
+
+QSGContext *QSGThreadedRenderLoop::sceneGraphContext() const
+{
+    return m_thread->sg;
+}
+
+bool QSGThreadedRenderLoop::anyoneShowing()
+{
+    for (int i=0; i<m_windows.size(); ++i) {
+        QQuickWindow *c = m_windows.at(i).window;
+        if (c->isVisible() && c->isExposed())
+            return true;
+    }
+    return false;
+}
+
+void QSGThreadedRenderLoop::animationStarted()
+{
+    RLDEBUG("GUI: animationStarted()");
+    if (!anyoneShowing() && m_animation_timer == 0)
+        m_animation_timer = startTimer(qsgrl_animation_interval());
+}
+
+void QSGThreadedRenderLoop::animationStopped()
+{
+    RLDEBUG("GUI: animationStopped()");
+    if (!anyoneShowing()) {
+        killTimer(m_animation_timer);
+        m_animation_timer = 0;
+    }
+}
+
+
+
+/*
+    Adds this window to the list of tracked windowes in this window
+    manager. show() does not trigger rendering to start, that happens
+    in expose.
+ */
+
+void QSGThreadedRenderLoop::show(QQuickWindow *window)
+{
+    RLDEBUG1("GUI: show()");
+
+    Window win;
+    win.window = window;
+    win.pendingUpdate = false;
+    m_windows << win;
+}
+
+
+
+/*
+    Removes this window from the list of tracked windowes in this
+    window manager. hide() will trigger obscure, which in turn will
+    stop rendering.
+ */
+
+void QSGThreadedRenderLoop::hide(QQuickWindow *window)
+{
+    RLDEBUG1("GUI: hide()");
+
+    if (window->isExposed())
+        handleObscurity(window);
+
+    releaseResources(window);
+
+    for (int i=0; i<m_windows.size(); ++i) {
+        if (m_windows.at(i).window == window) {
+            m_windows.removeAt(i);
+            break;
+        }
+    }
+}
+
+
+/*!
+    If the window is first hide it, then perform a complete cleanup
+    with releaseResources which will take down the GL context and
+    exit the rendering thread.
+ */
+void QSGThreadedRenderLoop::windowDestroyed(QQuickWindow *window)
+{
+    RLDEBUG1("GUI: windowDestroyed()");
+
+    if (window->isVisible())
+        hide(window);
+    releaseResources(window, true);
+
+    RLDEBUG1("GUI:  - done with windowDestroyed()");
+}
+
+
+void QSGThreadedRenderLoop::exposureChanged(QQuickWindow *window)
+{
+    RLDEBUG1("GUI: exposureChanged()");
+    if (windowFor(m_windows, window) == 0)
+        return;
+
+    if (window->isExposed()) {
+        handleExposure(window);
+    } else {
+        handleObscurity(window);
+    }
+}
+
+
+/*!
+    Will post an event to the render thread that this window should
+    start to render.
+ */
+void QSGThreadedRenderLoop::handleExposure(QQuickWindow *window)
+{
+    RLDEBUG1("GUI: handleExposure");
+
+    // Because we are going to bind a GL context to it, make sure it
+    // is created.
+    if (!window->handle())
+        window->create();
+
+    QCoreApplication::postEvent(m_thread, new WMExposeEvent(window));
+
+    // Start render thread if it is not running
+    if (!m_thread->isRunning()) {
+        m_thread->shouldExit = false;
+        m_thread->animationRunning = m_animation_driver->isRunning();
+
+        RLDEBUG1("GUI: - starting render thread...");
+        m_thread->start();
+
+    } else {
+        RLDEBUG1("GUI: - render thread already running");
+    }
+
+    polishAndSync();
+
+    // Kill non-visual animation timer if it is running
+    if (m_animation_timer) {
+        killTimer(m_animation_timer);
+        m_animation_timer = 0;
+    }
+
+}
+
+/*!
+    This function posts an event to the render thread to remove the window
+    from the list of windowses to render.
+
+    It also starts up the non-vsync animation tick if no more windows
+    are showing.
+ */
+void QSGThreadedRenderLoop::handleObscurity(QQuickWindow *window)
+{
+    RLDEBUG1("GUI: handleObscurity");
+    if (m_thread->isRunning())
+        QCoreApplication::postEvent(m_thread, new WMWindowEvent(window, WM_Obscure));
+
+    if (!anyoneShowing() && m_animation_driver->isRunning() && m_animation_timer == 0) {
+        m_animation_timer = startTimer(qsgrl_animation_interval());
+    }
+}
+
+
+/*!
+    Called whenever the QML scene has changed. Will post an event to
+    ourselves that a sync is needed.
+ */
+void QSGThreadedRenderLoop::maybeUpdate(QQuickWindow *window)
+{
+    Q_ASSERT_X(QThread::currentThread() == QCoreApplication::instance()->thread() || m_thread->guiIsLocked,
+               "QQuickItem::update()",
+               "Function can only be called from GUI thread or during QQuickItem::updatePaintNode()");
+
+    RLDEBUG("GUI: maybeUpdate...");
+    Window *w = windowFor(m_windows, window);
+    if (!w || w->pendingUpdate || !m_thread->isRunning()) {
+        return;
+    }
+
+    // Call this function from the Gui thread later as startTimer cannot be
+    // called from the render thread.
+    if (QThread::currentThread() == m_thread) {
+        RLDEBUG("GUI:  - on render thread, posting update later");
+        QCoreApplication::postEvent(this, new WMWindowEvent(window, WM_UpdateLater));
+        return;
+    }
+
+
+    w->pendingUpdate = true;
+
+    if (m_update_timer > 0) {
+        return;
+    }
+
+    RLDEBUG("GUI:  - posting update");
+    m_update_timer = startTimer(m_animation_driver->isRunning() ? m_exhaust_delay : 0, Qt::PreciseTimer);
+}
+
+/*!
+    Called when the QQuickWindow should be explicitly repainted. This function
+    can also be called on the render thread when the GUI thread is blocked to
+    keep render thread animations alive.
+ */
+void QSGThreadedRenderLoop::update(QQuickWindow *window)
+{
+    if (QThread::currentThread() == m_thread) {
+        RLDEBUG("Gui: update called on render thread");
+        m_thread->requestRepaint();
+        return;
+    }
+
+    RLDEBUG("Gui: update called");
+    maybeUpdate(window);
+}
+
+
+
+/*!
+ * Release resources will post an event to the render thread to
+ * free up the SG and GL resources and exists the render thread.
+ */
+void QSGThreadedRenderLoop::releaseResources(QQuickWindow *window, bool inDestructor)
+{
+    RLDEBUG1("GUI: releaseResources requested...");
+
+    m_thread->mutex.lock();
+    if (m_thread->isRunning() && !m_thread->shouldExit) {
+        RLDEBUG1("GUI:  - posting release request to render thread");
+        QCoreApplication::postEvent(m_thread, new WMTryReleaseEvent(window, inDestructor));
+        m_thread->waitCondition.wait(&m_thread->mutex);
+    }
+    m_thread->mutex.unlock();
+}
+
+
+
+void QSGThreadedRenderLoop::polishAndSync()
+{
+    if (!anyoneShowing())
+        return;
+
+#ifdef QQUICK_WINDOW_TIMING
+    QElapsedTimer timer;
+    int polishTime;
+    int waitTime;
+    if (qquick_window_timing)
+        timer.start();
+#endif
+    RLDEBUG("GUI: polishAndSync()");
+    // Polish as the last thing we do before we allow the sync to take place
+    for (int i=0; i<m_windows.size(); ++i) {
+        const Window &w = m_windows.at(i);
+        QQuickWindowPrivate *d = QQuickWindowPrivate::get(w.window);
+        d->polishItems();
+    }
+#ifdef QQUICK_WINDOW_TIMING
+    if (qquick_window_timing)
+        polishTime = timer.elapsed();
+#endif
+
+    RLDEBUG("GUI:  - clearing update flags...");
+    for (int i=0; i<m_windows.size(); ++i) {
+        m_windows[i].pendingUpdate = false;
+    }
+
+    RLDEBUG("GUI:  - lock for sync...");
+    m_thread->mutex.lock();
+    m_thread->guiIsLocked = true;
+    QEvent *event = new QEvent(WM_RequestSync);
+
+    QCoreApplication::postEvent(m_thread, event);
+    RLDEBUG("GUI:  - wait for sync...");
+#ifdef QQUICK_WINDOW_TIMING
+    if (qquick_window_timing)
+        waitTime = timer.elapsed();
+#endif
+    m_thread->waitCondition.wait(&m_thread->mutex);
+    m_thread->guiIsLocked = false;
+    m_thread->mutex.unlock();
+    RLDEBUG("GUI:  - unlocked after sync...");
+
+#ifdef QQUICK_WINDOW_TIMING
+    if (qquick_window_timing)
+        qDebug(" - polish=%d, wait=%d, sync=%d", polishTime, waitTime - polishTime, int(timer.elapsed() - waitTime));
+#endif
+}
+
+bool QSGThreadedRenderLoop::event(QEvent *e)
+{
+    switch ((int) e->type()) {
+
+    case QEvent::Timer:
+        if (static_cast<QTimerEvent *>(e)->timerId() == m_animation_timer) {
+            RLDEBUG("Gui: QEvent::Timer -> non-visual animation");
+            m_animation_driver->advance();
+        } else if (static_cast<QTimerEvent *>(e)->timerId() == m_update_timer) {
+            RLDEBUG("Gui: QEvent::Timer -> polishAndSync()");
+            killTimer(m_update_timer);
+            m_update_timer = 0;
+            polishAndSync();
+        }
+        return true;
+
+    case WM_UpdateLater: {
+        QQuickWindow *window = static_cast<WMWindowEvent *>(e)->window;
+        // The window might have gone away...
+        if (windowFor(m_windows, window))
+            maybeUpdate(window);
+        return true; }
+
+    case WM_AdvanceAnimations:
+        --m_thread->animationRequestsPending;
+        RLDEBUG("GUI: WM_AdvanceAnimations");
+        if (m_animation_driver->isRunning()) {
+#ifdef QQUICK_CANVAS_TIMING
+            QElapsedTimer timer;
+            timer.start();
+#endif
+            m_animation_driver->advance();
+            RLDEBUG("GUI:  - animations advanced..");
+#ifdef QQUICK_CANVAS_TIMING
+            if (qquick_canvas_timing)
+                qDebug(" - animation: %d", (int) timer.elapsed());
+#endif
+        }
+        return true;
+
+    default:
+        break;
+    }
+
+    return QObject::event(e);
+}
+
+
+
+/*
+    Locks down GUI and performs a grab the scene graph, then returns the result.
+
+    Since the QML scene could have changed since the last time it was rendered,
+    we need to polish and sync the scene graph. This might seem superfluous, but
+     - QML changes could have triggered deleteLater() which could have removed
+       textures or other objects from the scene graph, causing render to crash.
+     - Autotests rely on grab(), setProperty(), grab(), compare behavior.
+ */
+
+QImage QSGThreadedRenderLoop::grab(QQuickWindow *window)
+{
+    RLDEBUG("GUI: grab");
+    if (!m_thread->isRunning())
+        return QImage();
+
+    if (!window->handle())
+        window->create();
+
+    RLDEBUG1("GUI: - polishing items...");
+    QQuickWindowPrivate *d = QQuickWindowPrivate::get(window);
+    d->polishItems();
+
+    QImage result;
+    m_thread->mutex.lock();
+    RLDEBUG1("GUI: - locking, posting grab event");
+    QCoreApplication::postEvent(m_thread, new WMGrabEvent(window, &result));
+    m_thread->waitCondition.wait(&m_thread->mutex);
+    RLDEBUG1("GUI: - locking, grab done, unlocking");
+    m_thread->mutex.unlock();
+
+    RLDEBUG1("Gui: - grab complete");
+
+    return result;
+}
+
+/*
+    Notify the render thread that the window is now a new size. Then
+    locks GUI until render has adapted.
+ */
+
+void QSGThreadedRenderLoop::resize(QQuickWindow *w, const QSize &size)
+{
+    RLDEBUG1("GUI: resize");
+
+    if (!m_thread->isRunning() || !m_windows.size() || !w->isExposed() || windowFor(m_windows, w) == 0) {
+        return;
+    }
+
+    if (size.width() == 0 || size.height() == 0)
+        return;
+
+    RLDEBUG("GUI:  - posting resize event...");
+    WMResizeEvent *e = new WMResizeEvent(w, size);
+    QCoreApplication::postEvent(m_thread, e);
+
+    polishAndSync();
+}
+
+#include "qsgthreadedrenderloop.moc"
+
+QT_END_NAMESPACE
diff --git a/src/quick/scenegraph/qsgthreadedrenderloop_p.h b/src/quick/scenegraph/qsgthreadedrenderloop_p.h
new file mode 100644
index 0000000000..fd3ab657d3
--- /dev/null
+++ b/src/quick/scenegraph/qsgthreadedrenderloop_p.h
@@ -0,0 +1,125 @@
+/****************************************************************************
+**
+** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and Digia.  For licensing terms and
+** conditions see http://qt.digia.com/licensing.  For further information
+** use the contact form at http://qt.digia.com/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Digia gives you certain additional
+** rights.  These rights are described in the Digia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3.0 as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU General Public License version 3.0 requirements will be
+** met: http://www.gnu.org/copyleft/gpl.html.
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QSGTHREADEDRENDERLOOP_P_H
+#define QSGTHREADEDRENDERLOOP_P_H
+
+#include <QtCore/QThread>
+#include <QtGui/QOpenGLContext>
+#include <private/qsgcontext_p.h>
+
+#include "qsgrenderloop_p.h"
+
+QT_BEGIN_HEADER
+
+QT_BEGIN_NAMESPACE
+
+class QSGRenderThread;
+
+class QSGThreadedRenderLoop : public QObject, public QSGRenderLoop
+{
+    Q_OBJECT
+public:
+    QSGThreadedRenderLoop();
+
+    void show(QQuickWindow *window);
+    void hide(QQuickWindow *window);
+
+    void windowDestroyed(QQuickWindow *window);
+    void exposureChanged(QQuickWindow *window);
+
+    void handleExposure(QQuickWindow *window);
+    void handleObscurity(QQuickWindow *window);
+
+    QImage grab(QQuickWindow *);
+
+    void resize(QQuickWindow *, const QSize &);
+
+    void update(QQuickWindow *window);
+    void maybeUpdate(QQuickWindow *window);
+    QSGContext *sceneGraphContext() const;
+
+    QAnimationDriver *animationDriver() const;
+
+    void releaseResources(QQuickWindow *window) { releaseResources(window, false); }
+
+    bool event(QEvent *);
+
+    void wakeup();
+
+public slots:
+    void animationStarted();
+    void animationStopped();
+
+private:
+    friend class QSGRenderThread;
+
+    void releaseResources(QQuickWindow *window, bool inDestructor);
+    bool checkAndResetForceUpdate(QQuickWindow *window);
+
+    bool anyoneShowing();
+    void initialize();
+
+    void waitForReleaseComplete();
+
+    void polishAndSync();
+
+    struct Window {
+        QQuickWindow *window;
+        uint pendingUpdate : 1;
+    };
+
+    QSGRenderThread *m_thread;
+    QAnimationDriver *m_animation_driver;
+    QList<Window> m_windows;
+
+    int m_animation_timer;
+    int m_update_timer;
+    int m_exhaust_delay;
+};
+
+
+
+QT_END_NAMESPACE
+
+QT_END_HEADER
+
+#endif // QSGTHREADEDRENDERLOOP_P_H
diff --git a/src/quick/scenegraph/scenegraph.pri b/src/quick/scenegraph/scenegraph.pri
index a58e9b46ad..8c87e23ac9 100644
--- a/src/quick/scenegraph/scenegraph.pri
+++ b/src/quick/scenegraph/scenegraph.pri
@@ -65,7 +65,10 @@ HEADERS += \
     $$PWD/qsgdefaultimagenode_p.h \
     $$PWD/qsgdefaultrectanglenode_p.h \
     $$PWD/qsgflashnode_p.h \
-    $$PWD/qsgshareddistancefieldglyphcache_p.h
+    $$PWD/qsgshareddistancefieldglyphcache_p.h \
+    $$PWD/qsgrenderloop_p.h \
+    $$PWD/qsgthreadedrenderloop_p.h
+
 
 SOURCES += \
     $$PWD/qsgadaptationlayer.cpp \
@@ -79,7 +82,10 @@ SOURCES += \
     $$PWD/qsgdefaultimagenode.cpp \
     $$PWD/qsgdefaultrectanglenode.cpp \
     $$PWD/qsgflashnode.cpp \
-    $$PWD/qsgshareddistancefieldglyphcache.cpp
+    $$PWD/qsgshareddistancefieldglyphcache.cpp \
+    $$PWD/qsgrenderloop.cpp \
+    $$PWD/qsgthreadedrenderloop.cpp
+