Delay the deletion of QSGTextures until all windows are synchronized

With the 'basic' and the 'windows' render loop the scene graph
context is shared. Because of this we cannot start deleting textures
after the first window is synchronized as it may contain textures
needed by the another window, which is not yet synchronized.

QWindowPrivate::syncSceneGraph() is not calling endSync() anymore
as it doesn't know whether it is the last window or not. Instead
the renderloop is now responsible for calling endSync() once this
is safe to do.

Change-Id: Icb50ebfb447c928e38b41df7e26f3bfafdb4a811
Reviewed-by: Robert Griebl <robert.griebl@pelagicore.com>
Reviewed-by: Gunnar Sletta <gunnar@crimson.no>

10 files changed, 33 insertions, 2 deletions

diff --git a/src/plugins/scenegraph/d3d12/qsgd3d12renderloop.cpp b/src/plugins/scenegraph/d3d12/qsgd3d12renderloop.cpp
index 60b76deb2e..0d3f78d95d 100644
--- a/src/plugins/scenegraph/d3d12/qsgd3d12renderloop.cpp
+++ b/src/plugins/scenegraph/d3d12/qsgd3d12renderloop.cpp
@@ -461,6 +461,7 @@ void QSGD3D12RenderLoop::renderWindow(QQuickWindow *window)
     data.rc->initialize(nullptr);
 
     wd->syncSceneGraph();
+    data.rc->endSync();
 
     if (profileFrames)
         syncTime = renderTimer.nsecsElapsed();
diff --git a/src/plugins/scenegraph/d3d12/qsgd3d12threadedrenderloop.cpp b/src/plugins/scenegraph/d3d12/qsgd3d12threadedrenderloop.cpp
index 11cc257103..120a84566f 100644
--- a/src/plugins/scenegraph/d3d12/qsgd3d12threadedrenderloop.cpp
+++ b/src/plugins/scenegraph/d3d12/qsgd3d12threadedrenderloop.cpp
@@ -410,6 +410,7 @@ bool QSGD3D12RenderThread::event(QEvent *e)
             QQuickWindowPrivate *wd = QQuickWindowPrivate::get(wme->window);
             rc->initialize(nullptr);
             wd->syncSceneGraph();
+            rc->endSync();
             wd->renderSceneGraph(wme->window->size());
             *wme->image = engine->executeAndWaitReadbackRenderTarget();
         }
@@ -545,6 +546,7 @@ void QSGD3D12RenderThread::sync(bool inExpose)
 
         rc->initialize(nullptr);
         wd->syncSceneGraph();
+        rc->endSync();
 
         if (!hadRenderer && wd->renderer) {
             if (Q_UNLIKELY(debug_loop()))
diff --git a/src/plugins/scenegraph/openvg/qsgopenvgrenderloop.cpp b/src/plugins/scenegraph/openvg/qsgopenvgrenderloop.cpp
index f7aa704095..d31156f0eb 100644
--- a/src/plugins/scenegraph/openvg/qsgopenvgrenderloop.cpp
+++ b/src/plugins/scenegraph/openvg/qsgopenvgrenderloop.cpp
@@ -205,6 +205,7 @@ void QSGOpenVGRenderLoop::renderWindow(QQuickWindow *window)
     emit window->afterAnimating();
 
     cd->syncSceneGraph();
+    rc->endSync();
 
     if (profileFrames)
         syncTime = renderTimer.nsecsElapsed();
diff --git a/src/quick/items/qquickrendercontrol.cpp b/src/quick/items/qquickrendercontrol.cpp
index f2828bbedd..7e995936af 100644
--- a/src/quick/items/qquickrendercontrol.cpp
+++ b/src/quick/items/qquickrendercontrol.cpp
@@ -284,6 +284,7 @@ bool QQuickRenderControl::sync()
 
     QQuickWindowPrivate *cd = QQuickWindowPrivate::get(d->window);
     cd->syncSceneGraph();
+    d->rc->endSync();
 
     // TODO: find out if the sync actually caused a scenegraph update.
     return true;
@@ -383,6 +384,7 @@ QImage QQuickRenderControl::grab()
         QQuickWindowPrivate *cd = QQuickWindowPrivate::get(d->window);
         cd->polishItems();
         cd->syncSceneGraph();
+        d->rc->endSync();
         render();
         grabContent = qt_gl_read_framebuffer(d->window->size() * d->window->effectiveDevicePixelRatio(), false, false);
         if (QQuickRenderControl::renderWindowFor(d->window)) {
@@ -402,6 +404,7 @@ QImage QQuickRenderControl::grab()
             softwareRenderer->markDirty();
             cd->polishItems();
             cd->syncSceneGraph();
+            d->rc->endSync();
             render();
             softwareRenderer->setCurrentPaintDevice(prevDev);
         }
diff --git a/src/quick/items/qquickwindow.cpp b/src/quick/items/qquickwindow.cpp
index d30f1c3f78..433c5b25b1 100644
--- a/src/quick/items/qquickwindow.cpp
+++ b/src/quick/items/qquickwindow.cpp
@@ -432,10 +432,8 @@ void QQuickWindowPrivate::syncSceneGraph()
 
     emit q->afterSynchronizing();
     runAndClearJobs(&afterSynchronizingJobs);
-    context->endSync();
 }
 
-
 void QQuickWindowPrivate::renderSceneGraph(const QSize &size)
 {
     QML_MEMORY_SCOPE_STRING("SceneGraph");
diff --git a/src/quick/scenegraph/adaptations/software/qsgsoftwarerenderloop.cpp b/src/quick/scenegraph/adaptations/software/qsgsoftwarerenderloop.cpp
index 962db20cbc..3f0d1383b9 100644
--- a/src/quick/scenegraph/adaptations/software/qsgsoftwarerenderloop.cpp
+++ b/src/quick/scenegraph/adaptations/software/qsgsoftwarerenderloop.cpp
@@ -149,6 +149,7 @@ void QSGSoftwareRenderLoop::renderWindow(QQuickWindow *window, bool isNewExpose)
     emit window->afterAnimating();
 
     cd->syncSceneGraph();
+    rc->endSync();
 
     if (profileFrames)
         syncTime = renderTimer.nsecsElapsed();
diff --git a/src/quick/scenegraph/adaptations/software/qsgsoftwarethreadedrenderloop.cpp b/src/quick/scenegraph/adaptations/software/qsgsoftwarethreadedrenderloop.cpp
index 71db35377e..19f16a79fb 100644
--- a/src/quick/scenegraph/adaptations/software/qsgsoftwarethreadedrenderloop.cpp
+++ b/src/quick/scenegraph/adaptations/software/qsgsoftwarethreadedrenderloop.cpp
@@ -330,6 +330,7 @@ bool QSGSoftwareRenderThread::event(QEvent *e)
                 softwareRenderer->setBackingStore(backingStore);
             rc->initialize(nullptr);
             wd->syncSceneGraph();
+            rc->endSync();
             wd->renderSceneGraph(wme->window->size());
             *wme->image = backingStore->handle()->toImage();
         }
@@ -443,6 +444,7 @@ void QSGSoftwareRenderThread::sync(bool inExpose)
 
         rc->initialize(nullptr);
         wd->syncSceneGraph();
+        rc->endSync();
 
         if (!hadRenderer && wd->renderer) {
             qCDebug(QSG_RASTER_LOG_RENDERLOOP, "RT - created renderer");
diff --git a/src/quick/scenegraph/qsgrenderloop.cpp b/src/quick/scenegraph/qsgrenderloop.cpp
index c27700cf84..bc65dc1bc3 100644
--- a/src/quick/scenegraph/qsgrenderloop.cpp
+++ b/src/quick/scenegraph/qsgrenderloop.cpp
@@ -380,6 +380,16 @@ void QSGGuiThreadRenderLoop::renderWindow(QQuickWindow *window)
     bool alsoSwap = data.updatePending;
     data.updatePending = false;
 
+    bool lastDirtyWindow = true;
+    auto i = m_windows.constBegin();
+    while (i != m_windows.constEnd()) {
+        if (i.value().updatePending) {
+            lastDirtyWindow = false;
+            break;
+        }
+        i++;
+    }
+
     if (!current)
         return;
 
@@ -407,6 +417,8 @@ void QSGGuiThreadRenderLoop::renderWindow(QQuickWindow *window)
     emit window->afterAnimating();
 
     cd->syncSceneGraph();
+    if (lastDirtyWindow)
+        rc->endSync();
 
     if (profileFrames)
         syncTime = renderTimer.nsecsElapsed();
diff --git a/src/quick/scenegraph/qsgthreadedrenderloop.cpp b/src/quick/scenegraph/qsgthreadedrenderloop.cpp
index 2364fb714c..3a8e673c0d 100644
--- a/src/quick/scenegraph/qsgthreadedrenderloop.cpp
+++ b/src/quick/scenegraph/qsgthreadedrenderloop.cpp
@@ -425,6 +425,7 @@ bool QSGRenderThread::event(QEvent *e)
             qCDebug(QSG_LOG_RENDERLOOP) << QSG_RT_PAD << "- sync scene graph";
             QQuickWindowPrivate *d = QQuickWindowPrivate::get(ce->window);
             d->syncSceneGraph();
+            sgrc->endSync();
 
             qCDebug(QSG_LOG_RENDERLOOP) << QSG_RT_PAD << "- rendering scene graph";
             QQuickWindowPrivate::get(ce->window)->renderSceneGraph(ce->window->size());
diff --git a/src/quick/scenegraph/qsgwindowsrenderloop.cpp b/src/quick/scenegraph/qsgwindowsrenderloop.cpp
index e16f7ea966..e10e52d95e 100644
--- a/src/quick/scenegraph/qsgwindowsrenderloop.cpp
+++ b/src/quick/scenegraph/qsgwindowsrenderloop.cpp
@@ -445,6 +445,14 @@ void QSGWindowsRenderLoop::renderWindow(QQuickWindow *window)
         }
     }
 
+    bool lastDirtyWindow = true;
+    for (int i=0; i<m_windows.size(); ++i) {
+        if ( m_windows[i].pendingUpdate) {
+            lastDirtyWindow = false;
+            break;
+        }
+    }
+
     d->flushFrameSynchronousEvents();
     // Event delivery or processing has caused the window to stop rendering.
     if (!windowData(window))
@@ -464,6 +472,8 @@ void QSGWindowsRenderLoop::renderWindow(QQuickWindow *window)
 
     RLDEBUG(" - syncing");
     d->syncSceneGraph();
+    if (lastDirtyWindow)
+        m_rc->endSync();
     QSG_RENDER_TIMING_SAMPLE(QQuickProfiler::SceneGraphRenderLoopFrame, time_synced,
                              QQuickProfiler::SceneGraphRenderLoopSync);