Make connectNotify() work with QML

Call connectNotify() and disconnectNotify() in QQmlNotifierEndPoint,
which works for QML signal handlers and for QML bindings.

Task-number: QTBUG-11284
Change-Id: Ic9a08ee6687e5c7e606f315c8fb30eec1493cd83
Reviewed-by: Kent Hansen <kent.hansen@nokia.com>

10 files changed, 122 insertions, 45 deletions

diff --git a/src/qml/qml/qqmlabstractbinding_p.h b/src/qml/qml/qqmlabstractbinding_p.h
index ae92077add..1ce0a23149 100644
--- a/src/qml/qml/qqmlabstractbinding_p.h
+++ b/src/qml/qml/qqmlabstractbinding_p.h
@@ -63,8 +63,24 @@ QT_BEGIN_NAMESPACE
 class Q_QML_PRIVATE_EXPORT QQmlAbstractBinding
 {
 public:
+    enum DestroyMode {
+
+        // The binding should disconnect itself upon destroy
+        DisconnectBinding,
+
+        // The binding doesn't need to disconnect itself, but it can if it wants to.
+        //
+        // This is used in QQmlData::destroyed() - at the point at which the bindings are
+        // destroyed, the notifiers are already disconnected, so no need to disconnect each
+        // binding again.
+        //
+        // Bindings can use this flag to speed up destruction, especially for v4 bindings
+        // disconnecting a single binding might be slow.
+        KeepBindingConnected
+    };
+
     struct VTable {
-        void (*destroy)(QQmlAbstractBinding *);
+        void (*destroy)(QQmlAbstractBinding *, DestroyMode destroyMode);
         QString (*expression)(const QQmlAbstractBinding *);
         int (*propertyIndex)(const QQmlAbstractBinding *);
         QObject *(*object)(const QQmlAbstractBinding *);
@@ -82,7 +98,9 @@ public:
     // Bindings are free to implement their own memory management, so the delete operator is
     // not necessarily safe.  The default implementation clears the binding, removes it from
     // the object and calls delete.
-    void destroy() { vtable()->destroy(this); }
+    void destroy(DestroyMode destroyMode = DisconnectBinding)
+    { vtable()->destroy(this, destroyMode); }
+
     QString expression() const { return vtable()->expression(this); }
 
     // Should return the encoded property index for the binding.  Should return this value
@@ -108,7 +126,7 @@ public:
 
     // Default implementation for some VTable functions
     template<typename T>
-    static void default_destroy(QQmlAbstractBinding *);
+    static void default_destroy(QQmlAbstractBinding *, DestroyMode);
     static QString default_expression(const QQmlAbstractBinding *);
     static void default_retargetBinding(QQmlAbstractBinding *, QObject *, int);
 
@@ -182,8 +200,12 @@ QQmlAbstractBinding::BindingType QQmlAbstractBinding::bindingType() const
 }
 
 template<typename T>
-void QQmlAbstractBinding::default_destroy(QQmlAbstractBinding *This)
+void QQmlAbstractBinding::default_destroy(QQmlAbstractBinding *This, DestroyMode mode)
 {
+    // Assume the binding disconnects itself in the destructor, which for example QQmlBinding
+    // does in the destructor of its base class, QQmlJavaScriptExpression
+    Q_UNUSED(mode);
+
     This->removeFromObject();
     This->clear();
     delete static_cast<T *>(This);
diff --git a/src/qml/qml/qqmldata_p.h b/src/qml/qml/qqmldata_p.h
index 92c1a0cc68..5f5dafa1f9 100644
--- a/src/qml/qml/qqmldata_p.h
+++ b/src/qml/qml/qqmldata_p.h
@@ -145,6 +145,7 @@ public:
     void addNotify(int index, QQmlNotifierEndpoint *);
     int endpointCount(int index);
     bool signalHasEndpoint(int index);
+    void disconnectNotifiers();
 
     // The context that created the C++ object
     QQmlContextData *context; 
diff --git a/src/qml/qml/qqmlengine.cpp b/src/qml/qml/qqmlengine.cpp
index 90a71f997a..6ebd6b7666 100644
--- a/src/qml/qml/qqmlengine.cpp
+++ b/src/qml/qml/qqmlengine.cpp
@@ -483,6 +483,11 @@ void QQmlPrivate::qdeclarativeelement_destructor(QObject *o)
         // Mark this object as in the process of deletion to
         // prevent it resolving in bindings
         QQmlData::markAsDeleted(o);
+
+        // Disconnect the notifiers now - during object destruction this would be too late, since
+        // the disconnect call wouldn't be able to call disconnectNotify(), as it isn't possible to
+        // get the metaobject anymore.
+        d->disconnectNotifiers();
     }
 }
 
@@ -1330,6 +1335,21 @@ bool QQmlData::signalHasEndpoint(int index)
     return notifyList && (notifyList->connectionMask & (1ULL << quint64(index % 64)));
 }
 
+void QQmlData::disconnectNotifiers()
+{
+    if (notifyList) {
+        while (notifyList->todo)
+            notifyList->todo->disconnect();
+        for (int ii = 0; ii < notifyList->notifiesSize; ++ii) {
+            while (QQmlNotifierEndpoint *ep = notifyList->notifies[ii])
+                ep->disconnect();
+        }
+        free(notifyList->notifies);
+        free(notifyList);
+        notifyList = 0;
+    }
+}
+
 QHash<int, QObject *> *QQmlData::attachedProperties() const
 {
     if (!extendedData) extendedData = new QQmlDataExtended;
@@ -1410,17 +1430,7 @@ void QQmlData::destroyed(QObject *object)
         guard->objectDestroyed(object);
     }
 
-    if (notifyList) {
-        while (notifyList->todo)
-            notifyList->todo->disconnect();
-        for (int ii = 0; ii < notifyList->notifiesSize; ++ii) {
-            while (QQmlNotifierEndpoint *ep = notifyList->notifies[ii])
-                ep->disconnect();
-        }
-        free(notifyList->notifies);
-        free(notifyList);
-        notifyList = 0;
-    }
+    disconnectNotifiers();
 
     if (extendedData)
         delete extendedData;
diff --git a/src/qml/qml/qqmljavascriptexpression_p.h b/src/qml/qml/qqmljavascriptexpression_p.h
index dc9b4b63c6..09da661186 100644
--- a/src/qml/qml/qqmljavascriptexpression_p.h
+++ b/src/qml/qml/qqmljavascriptexpression_p.h
@@ -141,6 +141,7 @@ public:
     inline bool hasDelayedError() const;
     QQmlError error(QQmlEngine *) const;
     void clearError();
+    void clearGuards();
     QQmlDelayedError *delayedError();
 
     static void exceptionToError(v8::Handle<v8::Message>, QQmlError &);
@@ -185,8 +186,6 @@ private:
     //    activeGuards:flag2  - useSharedContext
     QBiPointer<QObject, DeleteWatcher> m_scopeObject;
     QForwardFieldList<Guard, &Guard::next> activeGuards;
-
-    void clearGuards();
 };
 
 QQmlJavaScriptExpression::DeleteWatcher::DeleteWatcher(QQmlJavaScriptExpression *e)
diff --git a/src/qml/qml/qqmlnotifier.cpp b/src/qml/qml/qqmlnotifier.cpp
index 2e451ee761..0d63012353 100644
--- a/src/qml/qml/qqmlnotifier.cpp
+++ b/src/qml/qml/qqmlnotifier.cpp
@@ -118,6 +118,8 @@ void QQmlNotifierEndpoint::connect(QObject *source, int sourceSignal, QQmlEngine
     QQmlPropertyPrivate::flushSignal(source, sourceSignal);
     QQmlData *ddata = QQmlData::get(source, true);
     ddata->addNotify(sourceSignal, this);
+    QObjectPrivate * const priv = QObjectPrivate::get(source);
+    priv->connectNotify(QMetaObjectPrivate::signal(source->metaObject(), sourceSignal));
 }
 
 QT_END_NAMESPACE
diff --git a/src/qml/qml/qqmlnotifier_p.h b/src/qml/qml/qqmlnotifier_p.h
index 7f5606fd68..2e5288291c 100644
--- a/src/qml/qml/qqmlnotifier_p.h
+++ b/src/qml/qml/qqmlnotifier_p.h
@@ -44,6 +44,8 @@
 
 #include "qqmldata_p.h"
 #include "qqmlguard_p.h"
+#include <QtCore/qmetaobject.h>
+#include <private/qmetaobject_p.h>
 
 QT_BEGIN_NAMESPACE
 
@@ -187,6 +189,11 @@ void QQmlNotifierEndpoint::connect(QQmlNotifier *notifier)
 
 void QQmlNotifierEndpoint::disconnect()
 {
+    if (sourceSignal != -1) {
+        QObject * const obj = senderAsObject();
+        QObjectPrivate * const priv = QObjectPrivate::get(obj);
+        priv->disconnectNotify(QMetaObjectPrivate::signal(obj->metaObject(), sourceSignal));
+    }
     if (next) next->prev = prev;
     if (prev) *prev = next;
     if (isNotifying()) *((intptr_t *)(senderPtr & ~0x1)) = 0;
diff --git a/src/qml/qml/v4/qv4bindings.cpp b/src/qml/qml/v4/qv4bindings.cpp
index 150a11d011..0088741170 100644
--- a/src/qml/qml/v4/qv4bindings.cpp
+++ b/src/qml/qml/v4/qv4bindings.cpp
@@ -382,10 +382,13 @@ void QV4Bindings::Binding::update(QQmlAbstractBinding *_This, QQmlPropertyPrivat
     This->parent->run(This, flags);
 }
 
-void QV4Bindings::Binding::destroy(QQmlAbstractBinding *_This)
+void QV4Bindings::Binding::destroy(QQmlAbstractBinding *_This, QQmlAbstractBinding::DestroyMode mode)
 {
     QV4Bindings::Binding *This = static_cast<QV4Bindings::Binding *>(_This);
 
+    if (mode == QQmlAbstractBinding::DisconnectBinding)
+        This->disconnect();
+
     This->setEnabledFlag(false);
     This->removeFromObject();
     This->clear();
@@ -417,8 +420,30 @@ void QV4Bindings::Binding::retargetBinding(QQmlAbstractBinding *_This, QObject *
     This->target.value().targetProperty = i;
 }
 
+void QV4Bindings::Binding::disconnect()
+{
+    // We iterate over the signal table to find all subscriptions associated with this binding.
+    // This is slow, but disconnect() is not called in the common case, only in special cases
+    // like when the binding is overwritten.
+    QV4Program * const program = parent->program;
+    for (quint16 subIndex = 0; subIndex < program->subscriptions; subIndex++) {
+        QV4Program::BindingReferenceList * const list = program->signalTable(subIndex);
+        for (quint32 bindingIndex = 0; bindingIndex < list->count; ++bindingIndex) {
+            QV4Program::BindingReference * const bindingRef = list->bindings + bindingIndex;
+            Binding * const binding = parent->bindings + bindingRef->binding;
+            if (binding == this) {
+                Subscription * const sub = parent->subscriptions + subIndex;
+                if (sub->active) {
+                    sub->active = false;
+                    sub->disconnect();
+                }
+            }
+        }
+    }
+}
+
 QV4Bindings::Subscription::Subscription()
-: bindings(0), method(-1)
+    : bindings(0), method(-1), active(false)
 {
     setCallback(QQmlNotifierEndpoint::QV4BindingsSubscription);
 }
@@ -526,22 +551,18 @@ void QV4Bindings::run(Binding *binding, QQmlPropertyPrivate::WriteFlags flags)
     }
 }
 
-
-void QV4Bindings::unsubscribe(int subIndex)
+void QV4Bindings::subscribeId(QQmlContextData *p, int idIndex, int subIndex)
 {
     Subscription *sub = (subscriptions + subIndex);
     sub->disconnect();
-}
-
-void QV4Bindings::subscribeId(QQmlContextData *p, int idIndex, int subIndex)
-{
-    unsubscribe(subIndex);
 
     if (p->idValues[idIndex]) {
-        Subscription *sub = (subscriptions + subIndex);
         sub->bindings = this;
         sub->method = subIndex;
         sub->connect(&p->idValues[idIndex].bindings);
+        sub->active = true;
+    } else {
+        sub->active = false;
     }
 }
 
@@ -552,10 +573,13 @@ void QV4Bindings::subscribe(QObject *o, int notifyIndex, int subIndex, QQmlEngin
         return;
     sub->bindings = this;
     sub->method = subIndex;
-    if (o)
+    if (o) {
         sub->connect(o, notifyIndex, e);
-    else
+        sub->active = true;
+    } else {
         sub->disconnect();
+        sub->active = false;
+    }
 }
 
 static bool testCompareVariants(const QVariant &qtscriptRaw, const QVariant &v4)
@@ -942,14 +966,6 @@ void QV4Bindings::run(int instrIndex, quint32 &executedBlocks,
         } else {
             INVALIDATION_CHECK(invalidated, object, instr->fetchAndSubscribe.property.coreIndex);
 
-            int subIdx = instr->fetchAndSubscribe.subscription;
-            Subscription *sub = 0;
-            if (subIdx != -1) {
-                sub = (subscriptions + subIdx);
-                sub->bindings = this;
-                sub->method = subIdx;
-            }
-
             const Register::Type valueType = (Register::Type)instr->fetchAndSubscribe.valueType;
             reg.init(valueType);
             if (instr->fetchAndSubscribe.valueType >= FirstCleanupType)
@@ -967,9 +983,22 @@ void QV4Bindings::run(int instrIndex, quint32 &executedBlocks,
             if (accessors->notifier) {
                 QQmlNotifier *notifier = 0;
                 accessors->notifier(object, instr->fetchAndSubscribe.property.accessorData, &notifier);
-                if (notifier) sub->connect(notifier);
-            } else if (instr->fetchAndSubscribe.property.notifyIndex != -1) {
-                sub->connect(object, instr->fetchAndSubscribe.property.notifyIndex, context->engine);
+                if (notifier) {
+                    int subIdx = instr->fetchAndSubscribe.subscription;
+                    Subscription *sub = 0;
+                    if (subIdx != -1) {
+                        sub = (subscriptions + subIdx);
+                        sub->bindings = this;
+                        sub->method = subIdx;
+                    }
+                    sub->connect(notifier);
+                }
+            } else {
+                const int notifyIndex = instr->fetchAndSubscribe.property.notifyIndex;
+                if (notifyIndex != -1) {
+                    const int subIdx = instr->fetchAndSubscribe.subscription;
+                    subscribe(object, notifyIndex, subIdx, context->engine);
+                }
             }
         }
     }
diff --git a/src/qml/qml/v4/qv4bindings_p.h b/src/qml/qml/v4/qv4bindings_p.h
index 0553e575a5..04fca8529f 100644
--- a/src/qml/qml/v4/qv4bindings_p.h
+++ b/src/qml/qml/v4/qv4bindings_p.h
@@ -84,13 +84,15 @@ public:
             : QQmlAbstractBinding(V4), target(0), scope(0), instruction(0), executedBlocks(0), parent(0) {}
 
         // Inherited from QQmlAbstractBinding
-        static void destroy(QQmlAbstractBinding *);
+        static void destroy(QQmlAbstractBinding *, QQmlAbstractBinding::DestroyMode mode);
         static int propertyIndex(const QQmlAbstractBinding *);
         static QObject *object(const QQmlAbstractBinding *);
         static void setEnabled(QQmlAbstractBinding *, bool, QQmlPropertyPrivate::WriteFlags);
         static void update(QQmlAbstractBinding *, QQmlPropertyPrivate::WriteFlags);
         static void retargetBinding(QQmlAbstractBinding *, QObject *, int);
 
+        void disconnect();
+
         struct Retarget {
             QObject *target;
             int targetProperty;
@@ -121,7 +123,10 @@ private:
     public:
         inline Subscription();
         QV4Bindings *bindings;
-        int method;
+        int method:31;
+
+        // Subscriptions are not shared between bindings (anymore), so this can be a simple bool flag
+        bool active:1;
     };
     friend void QV4BindingsSubscription_callback(QQmlNotifierEndpoint *e, void **);
 
@@ -144,7 +149,6 @@ private:
              );
 
 
-    inline void unsubscribe(int subIndex);
     inline void subscribeId(QQmlContextData *p, int idIndex, int subIndex);
     inline void subscribe(QObject *o, int notifyIndex, int subIndex, QQmlEngine *);
 
diff --git a/src/qml/qml/v8/qv8bindings.cpp b/src/qml/qml/v8/qv8bindings.cpp
index dd57d57ee7..a15831a39c 100644
--- a/src/qml/qml/v8/qv8bindings.cpp
+++ b/src/qml/qml/v8/qv8bindings.cpp
@@ -214,10 +214,13 @@ void QV8Bindings::Binding::expressionChanged(QQmlJavaScriptExpression *e)
     This->update(QQmlPropertyPrivate::DontRemoveBinding);
 }
 
-void QV8Bindings::Binding::destroy(QQmlAbstractBinding *_This)
+void QV8Bindings::Binding::destroy(QQmlAbstractBinding *_This, QQmlAbstractBinding::DestroyMode mode)
 {
     QV8Bindings::Binding *This = static_cast<QV8Bindings::Binding *>(_This);
 
+    if (mode == QQmlAbstractBinding::DisconnectBinding)
+        This->clearGuards();
+
     This->setEnabledFlag(false);
     This->setDestroyedFlag(true);
     This->removeFromObject();
diff --git a/src/qml/qml/v8/qv8bindings_p.h b/src/qml/qml/v8/qv8bindings_p.h
index ca5c028824..9fbeaeb0eb 100644
--- a/src/qml/qml/v8/qv8bindings_p.h
+++ b/src/qml/qml/v8/qv8bindings_p.h
@@ -94,7 +94,7 @@ public:
         static void expressionChanged(QQmlJavaScriptExpression *);
 
         // "Inherited" from QQmlAbstractBinding
-        static void destroy(QQmlAbstractBinding *);
+        static void destroy(QQmlAbstractBinding *, QQmlAbstractBinding::DestroyMode mode);
         static int propertyIndex(const QQmlAbstractBinding *);
         static QObject *object(const QQmlAbstractBinding *);
         static void setEnabled(QQmlAbstractBinding *, bool, QQmlPropertyPrivate::WriteFlags);