QtDBus: Move dispatch enabling code into a single function

Remove the helper class.

Change-Id: I82edd7fa1ce1d8b9044938a1378f992a40a0bbdf
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

src/dbus/qdbusconnection.cpp

@@ -148,13 +148,9 @@ QDBusConnectionPrivate *QDBusConnectionManager::connectToBus(QDBusConnection::Bu
     data.suspendedDelivery = suspendedDelivery;
 
     emit connectionRequested(&data);
-    if (suspendedDelivery && data.result->connection) {
+    if (suspendedDelivery && data.result->connection)
-        data.result->ref.ref();
+        data.result->enableDispatchDelayed(qApp); // qApp was checked in the caller
-        QDBusConnectionDispatchEnabler *o = new QDBusConnectionDispatchEnabler(data.result);
+
-        QMetaObject::invokeMethod(o, &QDBusConnectionDispatchEnabler::execute,
-                                  Qt::QueuedConnection);
-        o->moveToThread(qApp->thread());    // qApp was checked in the caller
-    }
     return data.result;
 }
 

src/dbus/qdbusconnection_p.h

@@ -212,6 +212,8 @@ public:
 
     void postEventToThread(int action, QObject *target, QEvent *event);
 
+    void enableDispatchDelayed(QObject *context);
+
 private:
     void checkThread();
     bool handleError(const QDBusErrorInternal &error);
@@ -357,27 +359,6 @@ extern QDBusMessage qDBusPropertySet(const QDBusConnectionPrivate::ObjectTreeNod
 extern QDBusMessage qDBusPropertyGetAll(const QDBusConnectionPrivate::ObjectTreeNode &node,
                                         const QDBusMessage &msg);
 
-// can be replaced with a lambda in Qt 5.7
-class QDBusConnectionDispatchEnabler : public QObject
-{
-    Q_OBJECT
-    QDBusConnectionPrivate *con;
-public:
-    QDBusConnectionDispatchEnabler(QDBusConnectionPrivate *con) : con(con) {}
-
-public slots:
-    void execute()
-    {
-        // This call cannot race with something disabling dispatch only because dispatch is
-        // never re-disabled from Qt code on an in-use connection once it has been enabled.
-        QMetaObject::invokeMethod(
-                con, [con = con]() { con->setDispatchEnabled(true); }, Qt::QueuedConnection);
-        if (!con->ref.deref())
-            con->deleteLater();
-        deleteLater();
-    }
-};
-
 #endif // QT_BOOTSTRAPPED
 
 QT_END_NAMESPACE

src/dbus/qdbusintegrator.cpp

@@ -293,12 +293,8 @@ static void qDBusNewConnection(DBusServer *server, DBusConnection *connection, v
     // QDBusServer's thread in order to enable it after the
     // QDBusServer::newConnection() signal has been received by the
     // application's code
-    newConnection->ref.ref();
     QReadLocker serverLock(&serverConnection->lock);
-    QDBusConnectionDispatchEnabler *o = new QDBusConnectionDispatchEnabler(newConnection);
+    newConnection->enableDispatchDelayed(serverConnection->serverObject);
-    QMetaObject::invokeMethod(o, &QDBusConnectionDispatchEnabler::execute, Qt::QueuedConnection);
-    if (serverConnection->serverObject)
-        o->moveToThread(serverConnection->serverObject->thread());
 }
 
 void QDBusConnectionPrivate::_q_newConnection(QDBusConnectionPrivate *newConnection)
@@ -2656,6 +2652,28 @@ void QDBusConnectionPrivate::postEventToThread(int action, QObject *object, QEve
     QDBusLockerBase::reportThreadAction(action, QDBusLockerBase::AfterPost, this);
 }
 
+/*
+ * Enable dispatch of D-Bus events for this connection, but only after
+ * context's thread's event loop has started and processed any already
+ * pending events. The event dispatch is then enabled in the DBus aux thread.
+ */
+void QDBusConnectionPrivate::enableDispatchDelayed(QObject *context)
+{
+    ref.ref();
+    QMetaObject::invokeMethod(
+            context,
+            [this]() {
+                // This call cannot race with something disabling dispatch only
+                // because dispatch is never re-disabled from Qt code on an
+                // in-use connection once it has been enabled.
+                QMetaObject::invokeMethod(
+                        this, [this] { setDispatchEnabled(true); }, Qt::QueuedConnection);
+                if (!ref.deref())
+                    deleteLater();
+            },
+            Qt::QueuedConnection);
+}
+
 QT_END_NAMESPACE
 
 #endif // QT_NO_DBUS