Enforce texture cleanup to happen at the end of the sync phase.

This was ok for the threaded renderer, but for the single-threaded
renderers where the event loop was spinning we could run the risk
of scheduling a texture for deleteLater() and then cleaning it
up before we got around to the sync phase.

Task-number: QTBUG-35670
Change-Id: I92074294b427fd8ab2a1823ba79c7ac3b59094ec
Reviewed-by: Michael Brasser <michael.brasser@live.com>

2 files changed, 12 insertions, 3 deletions

diff --git a/src/quick/scenegraph/qsgcontext.cpp b/src/quick/scenegraph/qsgcontext.cpp
index 1eeb9441b8..829d33a0d7 100644
--- a/src/quick/scenegraph/qsgcontext.cpp
+++ b/src/quick/scenegraph/qsgcontext.cpp
@@ -358,6 +358,12 @@ QSGRenderContext::~QSGRenderContext()
     invalidate();
 }
 
+void QSGRenderContext::endSync()
+{
+    qDeleteAll(m_texturesToDelete);
+    m_texturesToDelete.clear();
+}
+
 static QBasicMutex qsg_framerender_mutex;
 
 void QSGRenderContext::renderNextFrame(QSGRenderer *renderer, GLuint fboId)
@@ -475,6 +481,9 @@ void QSGRenderContext::invalidate()
     if (!m_gl)
         return;
 
+    qDeleteAll(m_texturesToDelete);
+    m_texturesToDelete.clear();
+
     qDeleteAll(m_textures.values());
     m_textures.clear();
 
@@ -617,10 +626,8 @@ QSGTexture *QSGRenderContext::textureForFactory(QQuickTextureFactory *factory, Q
 void QSGRenderContext::textureFactoryDestroyed(QObject *o)
 {
     m_mutex.lock();
-    QSGTexture *t = m_textures.take(static_cast<QQuickTextureFactory *>(o));
+    m_texturesToDelete << m_textures.take(static_cast<QQuickTextureFactory *>(o));
     m_mutex.unlock();
-    if (t)
-        t->deleteLater();
 }
 
 QT_END_NAMESPACE
diff --git a/src/quick/scenegraph/qsgcontext_p.h b/src/quick/scenegraph/qsgcontext_p.h
index c562a909c5..c1bf78a018 100644
--- a/src/quick/scenegraph/qsgcontext_p.h
+++ b/src/quick/scenegraph/qsgcontext_p.h
@@ -94,6 +94,7 @@ public:
     virtual void invalidate();
 
     virtual void renderNextFrame(QSGRenderer *renderer, GLuint fboId);
+    virtual void endSync();
 
     virtual QSharedPointer<QSGDepthStencilBuffer> depthStencilBufferForFbo(QOpenGLFramebufferObject *fbo);
     QSGDepthStencilBufferManager *depthStencilBufferManager();
@@ -124,6 +125,7 @@ protected:
 
     QMutex m_mutex;
     QHash<QQuickTextureFactory *, QSGTexture *> m_textures;
+    QSet<QSGTexture *> m_texturesToDelete;
     QSGAtlasTexture::Manager *m_atlasManager;
 
     QSGDepthStencilBufferManager *m_depthStencilManager;