Avoid calling gc in QQmlEngine destructor.

GC may be expensive. GC call in QQmlEngine doesn't have much sense
because V8 will destroy all objects living in a current context.
The only problem is that V8 may decide to not invoke weak callbacks
which may cause a memory leak. To avoid that we track all QObjects that
have JavaScript ownership set and we delete them explicitly.

The change reduce time of destroying QQmlEngine by 75%, which is really
visible in qquicklistmodel test.

Change-Id: I2a3668fd23630669114baee8c241a7ecc4100e33
Reviewed-by: Chris Adams <christopher.adams@nokia.com>

1 files changed, 1 insertions, 21 deletions

diff --git a/src/qml/qml/v8/qv8engine_p.h b/src/qml/qml/v8/qv8engine_p.h
index 1fc03d82e5..09e1ae537e 100644
--- a/src/qml/qml/v8/qv8engine_p.h
+++ b/src/qml/qml/v8/qv8engine_p.h
@@ -72,6 +72,7 @@
 
 #include <private/qqmlpropertycache_p.h>
 
+#include "qv8objectresource_p.h"
 #include "qv8contextwrapper_p.h"
 #include "qv8qobjectwrapper_p.h"
 #include "qv8stringwrapper_p.h"
@@ -91,12 +92,6 @@ QT_BEGIN_NAMESPACE
 // a handle, qFatal() is called.
 // #define QML_GLOBAL_HANDLE_DEBUGGING
 
-#define V8_RESOURCE_TYPE(resourcetype) \
-public: \
-    enum { V8ResourceType = QV8ObjectResource:: resourcetype }; \
-    virtual QV8ObjectResource::ResourceType resourceType() const { return QV8ObjectResource:: resourcetype; } \
-private: 
-
 #define V8ENGINE() ((QV8Engine *)v8::External::Unwrap(args.Data()))
 #define V8FUNCTION(function, engine) v8::FunctionTemplate::New(function, v8::External::Wrap((QV8Engine*)engine))->GetFunction()
 #define V8THROW_ERROR(string) { \
@@ -132,21 +127,6 @@ private:
     } \
 
 
-class QV8Engine;
-class QV8ObjectResource : public v8::Object::ExternalResource
-{
-public:
-    QV8ObjectResource(QV8Engine *engine) : engine(engine) { Q_ASSERT(engine); }
-    enum ResourceType { ContextType, QObjectType, TypeType, ListType, VariantType, 
-                        ValueTypeType, XMLHttpRequestType, DOMNodeType, SQLDatabaseType,
-                        ListModelType, Context2DType, Context2DStyleType, Context2DPixelArrayType, 
-                        ParticleDataType, SignalHandlerType, IncubatorType, VisualDataItemType,
-                        SequenceType, LocaleDataType };
-    virtual ResourceType resourceType() const = 0;
-
-    QV8Engine *engine;
-};
-
 template<class T>
 inline T *v8_resource_cast(v8::Handle<v8::Object> object) {
     QV8ObjectResource *resource = static_cast<QV8ObjectResource *>(object->GetExternalResource());