Don't store texture references after the view has gone away

This is a partial fix only. We will eventually need to get
proper sharing of resources across multiple GL contexts, but this
fixes the autotest and will work for most usecases.

The task QTBUG-19455 has been created to solve it properly.

6 files changed, 98 insertions, 30 deletions

diff --git a/src/declarative/items/qsgborderimage.cpp b/src/declarative/items/qsgborderimage.cpp
index 108d87ef28..9a8a8818e8 100644
--- a/src/declarative/items/qsgborderimage.cpp
+++ b/src/declarative/items/qsgborderimage.cpp
@@ -322,7 +322,9 @@ QSGNode *QSGBorderImage::updatePaintNode(QSGNode *oldNode, UpdatePaintNodeData *
 {
     Q_D(QSGBorderImage);
 
-    if (!d->pix.texture() || width() <= 0 || height() <= 0) {
+    QSGTexture *texture = d->pix.texture(d->sceneGraphContext());
+
+    if (!texture || width() <= 0 || height() <= 0) {
         delete oldNode;
         return 0;
     }
@@ -333,7 +335,7 @@ QSGNode *QSGBorderImage::updatePaintNode(QSGNode *oldNode, UpdatePaintNodeData *
         node = new QSGNinePatchNode();
     }
 
-    node->setTexture(d->pix.texture());
+    node->setTexture(texture);
 
     const QSGScaleGrid *border = d->getScaleGrid();
     node->setInnerRect(QRectF(border->left(),
diff --git a/src/declarative/items/qsgcanvas.cpp b/src/declarative/items/qsgcanvas.cpp
index d17df05ee3..c0a5ceff58 100644
--- a/src/declarative/items/qsgcanvas.cpp
+++ b/src/declarative/items/qsgcanvas.cpp
@@ -959,7 +959,19 @@ QSGCanvas::~QSGCanvas()
     delete d->rootItem; d->rootItem = 0;
     d->cleanupNodes();
 
+
+    // We need to remove all references to textures pointing to "our" QSGContext
+    // from the QDeclarativePixmapCache. Call into the cache to remove the GL / Scene Graph
+    // part of those cache entries.
+    // To "play nice" with other GL apps that are potentially running in the GUI thread,
+    // We get the current context and only temporarily make our own current
+    QGLContext *currentContext = const_cast<QGLContext *>(QGLContext::currentContext());
+    makeCurrent();
+    extern void qt_declarative_pixmapstore_clean(QSGContext *context);
+    qt_declarative_pixmapstore_clean(d->context);
     delete d->context;
+    if (currentContext)
+        currentContext->makeCurrent();
 }
 
 QSGItem *QSGCanvas::rootItem() const
diff --git a/src/declarative/items/qsgimage.cpp b/src/declarative/items/qsgimage.cpp
index c77f7a47db..706aaa7d5d 100644
--- a/src/declarative/items/qsgimage.cpp
+++ b/src/declarative/items/qsgimage.cpp
@@ -178,7 +178,7 @@ QRectF QSGImage::boundingRect() const
 QSGTexture *QSGImage::texture() const
 {
     Q_D(const QSGImage);
-    QSGTexture *t = d->pix.texture();
+    QSGTexture *t = d->pix.texture(d->sceneGraphContext());
     if (t) {
         t->setFiltering(QSGItemPrivate::get(this)->smooth ? QSGTexture::Linear : QSGTexture::Nearest);
         t->setMipmapFiltering(QSGTexture::None);
@@ -192,7 +192,9 @@ QSGNode *QSGImage::updatePaintNode(QSGNode *oldNode, UpdatePaintNodeData *)
 {
     Q_D(QSGImage);
 
-    if (!d->pix.texture() || width() <= 0 || height() <= 0) {
+    QSGTexture *texture = d->pix.texture(d->sceneGraphContext());
+
+    if (!texture || width() <= 0 || height() <= 0) {
         delete oldNode;
         return 0;
     }
@@ -201,15 +203,14 @@ QSGNode *QSGImage::updatePaintNode(QSGNode *oldNode, UpdatePaintNodeData *)
     if (!node) { 
         d->pixmapChanged = true;
         node = d->sceneGraphContext()->createImageNode();
-        node->setTexture(d->pix.texture());
+        node->setTexture(texture);
     }
 
     if (d->pixmapChanged) {
         // force update the texture in the node to trigger reconstruction of
         // geometry and the likes when a atlas segment has changed.
-        QSGTexture *t = d->pix.texture();
         node->setTexture(0);
-        node->setTexture(t);
+        node->setTexture(texture);
         d->pixmapChanged = false;
     }
 
diff --git a/src/declarative/util/qdeclarativepixmapcache.cpp b/src/declarative/util/qdeclarativepixmapcache.cpp
index ef0c422411..ddb0032644 100644
--- a/src/declarative/util/qdeclarativepixmapcache.cpp
+++ b/src/declarative/util/qdeclarativepixmapcache.cpp
@@ -103,7 +103,7 @@ public:
     class Event : public QEvent {
     public:
         Event(ReadError, const QString &, const QSize &, const QImage &image);
-        Event(ReadError, const QString &, const QSize &, QSGTexture *t, QSGContext *context);
+        Event(ReadError, const QString &, const QSize &, QSGTexture *t, QSGContext *context, const QImage &image);
 
         ReadError error;
         QString errorString;
@@ -113,7 +113,7 @@ public:
         QSGContext *context;
     };
     void postReply(ReadError, const QString &, const QSize &, const QImage &);
-    void postReply(ReadError, const QString &, const QSize &, QSGTexture *t, QSGContext *context);
+    void postReply(ReadError, const QString &, const QSize &, QSGTexture *t, QSGContext *context, const QImage &image);
 
 
 Q_SIGNALS:
@@ -211,9 +211,9 @@ public:
     {
     }
 
-    QDeclarativePixmapData(const QUrl &u, QSGTexture *t, QSGContext *c, const QSize &s, const QSize &r)
+    QDeclarativePixmapData(const QUrl &u, QSGTexture *t, QSGContext *c, const QPixmap &p, const QSize &s, const QSize &r)
     : refCount(1), inCache(false), privatePixmap(false), pixmapStatus(QDeclarativePixmap::Ready),
-      url(u), implicitSize(s), requestSize(r), texture(t), context(c), reply(0), prevUnreferenced(0),
+      url(u), pixmap(p), implicitSize(s), requestSize(r), texture(t), context(c), reply(0), prevUnreferenced(0),
       prevUnreferencedPtr(0), nextUnreferenced(0)
     {
     }
@@ -282,10 +282,10 @@ void QDeclarativePixmapReply::postReply(ReadError error, const QString &errorStr
 
 void QDeclarativePixmapReply::postReply(ReadError error, const QString &errorString,
                                         const QSize &implicitSize, QSGTexture *texture,
-                                        QSGContext *context)
+                                        QSGContext *context, const QImage &image)
 {
     loading = false;
-    QCoreApplication::postEvent(this, new Event(error, errorString, implicitSize, texture, context));
+    QCoreApplication::postEvent(this, new Event(error, errorString, implicitSize, texture, context, image));
 }
 
 QDeclarativePixmapReply::Event::Event(ReadError e, const QString &s, const QSize &iSize, const QImage &i)
@@ -293,8 +293,8 @@ QDeclarativePixmapReply::Event::Event(ReadError e, const QString &s, const QSize
 {
 }
 
-QDeclarativePixmapReply::Event::Event(ReadError e, const QString &s, const QSize &iSize, QSGTexture *t, QSGContext *c)
-    : QEvent(QEvent::User), error(e), errorString(s), implicitSize(iSize), texture(t), context(c)
+QDeclarativePixmapReply::Event::Event(ReadError e, const QString &s, const QSize &iSize, QSGTexture *t, QSGContext *c, const QImage &i)
+    : QEvent(QEvent::User), error(e), errorString(s), implicitSize(iSize), image(i), texture(t), context(c)
 {
 }
 
@@ -419,7 +419,7 @@ void QDeclarativePixmapReader::networkRequestDone(QNetworkReply *reply)
         mutex.lock();
         if (!cancelled.contains(job)) {
             if (texture)
-                job->postReply(error, errorString, readSize, texture, ctx);
+                job->postReply(error, errorString, readSize, texture, ctx, image);
             else
                 job->postReply(error, errorString, readSize, image);
         } else {
@@ -514,7 +514,7 @@ void QDeclarativePixmapReader::processJob(QDeclarativePixmapReply *runningJob, c
             mutex.lock();
             if (!cancelled.contains(runningJob)) {
                 if (sgContext)
-                    runningJob->postReply(errorCode, errorStr, readSize, sgContext->createTexture(image), sgContext);
+                    runningJob->postReply(errorCode, errorStr, readSize, sgContext->createTexture(image), sgContext, image);
                 else
                     runningJob->postReply(errorCode, errorStr, readSize, image);
             }
@@ -530,7 +530,7 @@ void QDeclarativePixmapReader::processJob(QDeclarativePixmapReply *runningJob, c
             mutex.lock();
             if (!cancelled.contains(runningJob)) {
                 if (sgContext)
-                    runningJob->postReply(errorCode, errorStr, readSize, sgContext->createTexture(image), sgContext);
+                    runningJob->postReply(errorCode, errorStr, readSize, sgContext->createTexture(image), sgContext, image);
                 else
                     runningJob->postReply(errorCode, errorStr, readSize, image);
             }
@@ -545,7 +545,7 @@ void QDeclarativePixmapReader::processJob(QDeclarativePixmapReply *runningJob, c
             }
             mutex.lock();
             if (!cancelled.contains(runningJob))
-                runningJob->postReply(errorCode, errorStr, readSize, t, sgContext);
+                runningJob->postReply(errorCode, errorStr, readSize, t, sgContext, QImage());
             mutex.unlock();
 
         }
@@ -577,7 +577,7 @@ void QDeclarativePixmapReader::processJob(QDeclarativePixmapReply *runningJob, c
             mutex.lock();
             if (!cancelled.contains(runningJob)) {
                 if (texture)
-                    runningJob->postReply(errorCode, errorStr, readSize, texture, sgContext);
+                    runningJob->postReply(errorCode, errorStr, readSize, texture, sgContext, image);
                 else
                     runningJob->postReply(errorCode, errorStr, readSize, image);
             } else {
@@ -678,6 +678,8 @@ inline uint qHash(const QDeclarativePixmapKey &key)
     return qHash(*key.url) ^ key.size->width() ^ key.size->height();
 }
 
+class QSGContext;
+
 class QDeclarativePixmapStore : public QObject
 {
     Q_OBJECT
@@ -693,6 +695,9 @@ protected:
 public:
     QHash<QDeclarativePixmapKey, QDeclarativePixmapData *> m_cache;
 
+    void cleanTexturesForContext(QSGContext *context);
+    void cleanTextureForContext(QDeclarativePixmapData *data);
+
 private:
     void shrinkCache(int remove);
 
@@ -704,11 +709,52 @@ private:
 };
 Q_GLOBAL_STATIC(QDeclarativePixmapStore, pixmapStore);
 
+
+void qt_declarative_pixmapstore_clean(QSGContext *context)
+{
+    pixmapStore()->cleanTexturesForContext(context);
+}
+
+
 QDeclarativePixmapStore::QDeclarativePixmapStore()
 : m_unreferencedPixmaps(0), m_lastUnreferencedPixmap(0), m_unreferencedCost(0), m_timerId(-1)
 {
 }
 
+void QDeclarativePixmapStore::cleanTextureForContext(QDeclarativePixmapData *data)
+{
+    if (data->context) {
+        Q_ASSERT(QGLContext::currentContext());
+        delete data->texture;
+        data->context = 0;
+        data->texture = 0;
+    }
+}
+
+void QDeclarativePixmapStore::cleanTexturesForContext(QSGContext *context)
+{
+    QDeclarativePixmapData *data = m_unreferencedPixmaps;
+    while (data) {
+        if (data->context == context)
+            cleanTextureForContext(data);
+        if (data == m_lastUnreferencedPixmap)
+            break;
+        data = data->nextUnreferenced;
+    }
+
+    QHash<QDeclarativePixmapKey, QDeclarativePixmapData *>::iterator it = m_cache.begin();
+    while (it != m_cache.end()) {
+        data = *it;
+        if (data->context == context) {
+            cleanTextureForContext(data);
+        }
+        ++it;
+    }
+
+}
+
+
+
 void QDeclarativePixmapStore::unreferencePixmap(QDeclarativePixmapData *data)
 {
     Q_ASSERT(data->prevUnreferenced == 0);
@@ -896,7 +942,7 @@ static QDeclarativePixmapData* createPixmapDataSync(QDeclarativeEngine *engine,
                 QSGTexture *texture = ep->getTextureFromProvider(url, &readSize, requestSize);
                 if (texture) {
                     *ok = true;
-                    return new QDeclarativePixmapData(url, texture, sgContext, readSize, requestSize);
+                    return new QDeclarativePixmapData(url, texture, sgContext, QPixmap(), readSize, requestSize);
                 }
             }
 
@@ -907,7 +953,7 @@ static QDeclarativePixmapData* createPixmapDataSync(QDeclarativeEngine *engine,
                     *ok = true;
                     if (sgContext) {
                         QSGTexture *t = sgContext->createTexture(image);
-                        return new QDeclarativePixmapData(url, t, sgContext,readSize, requestSize);
+                        return new QDeclarativePixmapData(url, t, sgContext, QPixmap::fromImage(image), readSize, requestSize);
                     }
                     return new QDeclarativePixmapData(url, QPixmap::fromImage(image), readSize, requestSize);
                 }
@@ -919,7 +965,7 @@ static QDeclarativePixmapData* createPixmapDataSync(QDeclarativeEngine *engine,
                     *ok = true;
                     if (sgContext) {
                         QSGTexture *t = sgContext->createTexture(pixmap.toImage());
-                        return new QDeclarativePixmapData(url, t, sgContext,readSize, requestSize);
+                        return new QDeclarativePixmapData(url, t, sgContext, pixmap, readSize, requestSize);
                     }
                     return new QDeclarativePixmapData(url, pixmap, readSize, requestSize);
                 }
@@ -959,7 +1005,7 @@ static QDeclarativePixmapData* createPixmapDataSync(QDeclarativeEngine *engine,
         }
 
         if (texture)
-            return new QDeclarativePixmapData(url, texture, ctx, readSize, requestSize);
+            return new QDeclarativePixmapData(url, texture, ctx, QPixmap::fromImage(image), readSize, requestSize);
         else
             return new QDeclarativePixmapData(url, QPixmap::fromImage(image), readSize, requestSize);
 
@@ -1062,9 +1108,17 @@ const QSize &QDeclarativePixmap::requestSize() const
         return nullPixmap()->size;
 }
 
-QSGTexture *QDeclarativePixmap::texture() const
+QSGTexture *QDeclarativePixmap::texture(QSGContext *context) const
 {
-    return d ? d->texture : 0;
+    if (d) {
+        if (d->texture)
+            return d->texture;
+        else if (d->pixmapStatus == Ready) {
+            d->texture = context->createTexture(d->pixmap.toImage());
+            return d->texture;
+        }
+    }
+    return 0;
 }
 
 const QPixmap &QDeclarativePixmap::pixmap() const
diff --git a/src/declarative/util/qdeclarativepixmapcache_p.h b/src/declarative/util/qdeclarativepixmapcache_p.h
index b917693e3e..84d22d65a7 100644
--- a/src/declarative/util/qdeclarativepixmapcache_p.h
+++ b/src/declarative/util/qdeclarativepixmapcache_p.h
@@ -56,6 +56,7 @@ QT_MODULE(Declarative)
 class QDeclarativeEngine;
 class QDeclarativePixmapData;
 class QSGTexture;
+class QSGContext;
 
 class Q_DECLARATIVE_EXPORT QDeclarativePixmap
 {
@@ -87,7 +88,7 @@ public:
     const QPixmap &pixmap() const;
     void setPixmap(const QPixmap &);
 
-    QSGTexture *texture() const;
+    QSGTexture *texture(QSGContext *context) const;
 
     QRect rect() const;
     int width() const;
diff --git a/src/imports/particles/pictureaffector.cpp b/src/imports/particles/pictureaffector.cpp
index d684b3fd80..636e26b830 100644
--- a/src/imports/particles/pictureaffector.cpp
+++ b/src/imports/particles/pictureaffector.cpp
@@ -72,9 +72,7 @@ void PictureAffector::startLoadImage()
 }
 void PictureAffector::loadImage()
 {
-    QSGPlainTexture* ptext = qobject_cast<QSGPlainTexture*>(m_pix->texture());
-    if(ptext)
-        m_loadedImage = ptext->image();
+    m_loadedImage = m_pix->pixmap().toImage();
     if(m_loadedImage.isNull())
         qWarning() << "PictureAffector could not load picture " << m_image;
 }