diff options
| -rw-r--r-- | src/dbus/qdbusconnection_p.h | 13 | ||||
| -rw-r--r-- | src/dbus/qdbusintegrator.cpp | 35 | ||||
| -rw-r--r-- | tests/auto/qdbusconnection/tst_qdbusconnection.cpp | 69 |
3 files changed, 108 insertions, 9 deletions
diff --git a/src/dbus/qdbusconnection_p.h b/src/dbus/qdbusconnection_p.h index 1bd00da..67145b8 100644 --- a/src/dbus/qdbusconnection_p.h +++ b/src/dbus/qdbusconnection_p.h @@ -203,6 +203,8 @@ public: void disconnectRelay(const QString &service, const QString &path, const QString &interface, QDBusAbstractInterface *receiver, const char *signal); + void registerService(const QString &serviceName); + void unregisterService(const QString &serviceName); bool handleMessage(const QDBusMessage &msg); void waitForFinished(QDBusPendingCallPrivate *pcall); @@ -247,9 +249,11 @@ public slots: void socketWrite(int); void objectDestroyed(QObject *o); void relaySignal(QObject *obj, const QMetaObject *, int signalId, const QVariantList &args); - void _q_serviceOwnerChanged(const QString &name, const QString &oldOwner, const QString &newOwner); - void registerService(const QString &serviceName); - void unregisterService(const QString &serviceName); + +private slots: + void serviceOwnerChangedNoLock(const QString &name, const QString &oldOwner, const QString &newOwner); + void registerServiceNoLock(const QString &serviceName); + void unregisterServiceNoLock(const QString &serviceName); signals: void serviceOwnerChanged(const QString &name, const QString &oldOwner, const QString &newOwner); @@ -303,6 +307,9 @@ public: QObject *receiver, const char *signal, int minMIdx, bool buildSignature); static DBusHandlerResult messageFilter(DBusConnection *, DBusMessage *, void *); + static bool checkReplyForDelivery(QDBusConnectionPrivate *target, QObject *object, + int idx, const QList<int> &metaTypes, + const QDBusMessage &msg); static QDBusCallDeliveryEvent *prepareReply(QDBusConnectionPrivate *target, QObject *object, int idx, const QList<int> &metaTypes, const QDBusMessage &msg); diff --git a/src/dbus/qdbusintegrator.cpp b/src/dbus/qdbusintegrator.cpp index a5d8ada..1842e5a 100644 --- a/src/dbus/qdbusintegrator.cpp +++ b/src/dbus/qdbusintegrator.cpp @@ -552,6 +552,9 @@ bool QDBusConnectionPrivate::handleMessage(const QDBusMessage &amsg) (*(*list)[i])(amsg); } + if (!ref) + return false; + switch (amsg.type()) { case QDBusMessage::SignalMessage: handleSignal(amsg); @@ -713,6 +716,8 @@ static int findSlot(const QMetaObject *mo, const QByteArray &name, int flags, return -1; } +static QDBusCallDeliveryEvent * const DIRECT_DELIVERY = (QDBusCallDeliveryEvent *)1; + QDBusCallDeliveryEvent* QDBusConnectionPrivate::prepareReply(QDBusConnectionPrivate *target, QObject *object, int idx, const QList<int> &metaTypes, @@ -736,6 +741,8 @@ QDBusCallDeliveryEvent* QDBusConnectionPrivate::prepareReply(QDBusConnectionPriv // we can deliver // prepare for the call + if (target == object) + return DIRECT_DELIVERY; return new QDBusCallDeliveryEvent(QDBusConnection(target), idx, target, msg, metaTypes); } @@ -750,6 +757,12 @@ void QDBusConnectionPrivate::activateSignal(const QDBusConnectionPrivate::Signal // Slots can optionally have one final parameter that is a QDBusMessage // Slots receive read-only copies of the message (i.e., pass by value or by const-ref) QDBusCallDeliveryEvent *call = prepareReply(this, hook.obj, hook.midx, hook.params, msg); + if (call == DIRECT_DELIVERY) { + // short-circuit delivery + Q_ASSERT(this == hook.obj); + deliverCall(this, 0, msg, hook.params, hook.midx); + return; + } if (call) postEventToThread(ActivateSignalAction, hook.obj, call); } @@ -1207,11 +1220,11 @@ void QDBusConnectionPrivate::relaySignal(QObject *obj, const QMetaObject *mo, in q_dbus_message_unref(msg); } -void QDBusConnectionPrivate::_q_serviceOwnerChanged(const QString &name, - const QString &oldOwner, const QString &newOwner) +void QDBusConnectionPrivate::serviceOwnerChangedNoLock(const QString &name, + const QString &oldOwner, const QString &newOwner) { Q_UNUSED(oldOwner); - QDBusWriteLocker locker(UpdateSignalHookOwnerAction, this); +// QDBusWriteLocker locker(UpdateSignalHookOwnerAction, this); WatchedServicesHash::Iterator it = watchedServices.find(name); if (it == watchedServices.end()) return; @@ -1686,11 +1699,11 @@ void QDBusConnectionPrivate::setConnection(DBusConnection *dbc, const QDBusError hook.obj = this; hook.params << QMetaType::Void << QVariant::String; // both functions take a QString as parameter and return void - hook.midx = staticMetaObject.indexOfSlot("registerService(QString)"); + hook.midx = staticMetaObject.indexOfSlot("registerServiceNoLock(QString)"); Q_ASSERT(hook.midx != -1); signalHooks.insert(QLatin1String("NameAcquired:" DBUS_INTERFACE_DBUS), hook); - hook.midx = staticMetaObject.indexOfSlot("unregisterService(QString)"); + hook.midx = staticMetaObject.indexOfSlot("unregisterServiceNoLock(QString)"); Q_ASSERT(hook.midx != -1); signalHooks.insert(QLatin1String("NameLost:" DBUS_INTERFACE_DBUS), hook); @@ -2081,7 +2094,7 @@ void QDBusConnectionPrivate::connectSignal(const QString &key, const SignalHook // we need to watch for this service changing connectSignal(dbusServiceString(), QString(), dbusInterfaceString(), QLatin1String("NameOwnerChanged"), QStringList() << hook.service, QString(), - this, SLOT(_q_serviceOwnerChanged(QString,QString,QString))); + this, SLOT(serviceOwnerChangedNoLock(QString,QString,QString))); data.owner = getNameOwnerNoCache(hook.service); qDBusDebug() << this << "Watching service" << hook.service << "for owner changes (current owner:" << data.owner << ")"; @@ -2342,12 +2355,22 @@ QDBusConnectionPrivate::findMetaObject(const QString &service, const QString &pa void QDBusConnectionPrivate::registerService(const QString &serviceName) { QDBusWriteLocker locker(RegisterServiceAction, this); + registerServiceNoLock(serviceName); +} + +void QDBusConnectionPrivate::registerServiceNoLock(const QString &serviceName) +{ serviceNames.append(serviceName); } void QDBusConnectionPrivate::unregisterService(const QString &serviceName) { QDBusWriteLocker locker(UnregisterServiceAction, this); + unregisterServiceNoLock(serviceName); +} + +void QDBusConnectionPrivate::unregisterServiceNoLock(const QString &serviceName) +{ serviceNames.removeAll(serviceName); } diff --git a/tests/auto/qdbusconnection/tst_qdbusconnection.cpp b/tests/auto/qdbusconnection/tst_qdbusconnection.cpp index 599abbd..4494d6f 100644 --- a/tests/auto/qdbusconnection/tst_qdbusconnection.cpp +++ b/tests/auto/qdbusconnection/tst_qdbusconnection.cpp @@ -106,6 +106,8 @@ private slots: void slotsWithLessParameters(); void nestedCallWithCallback(); + void serviceRegistrationRaceCondition(); + public: QString serviceName() const { return "com.trolltech.Qt.Autotests.QDBusConnection"; } bool callMethod(const QDBusConnection &conn, const QString &path); @@ -647,6 +649,73 @@ void tst_QDBusConnection::nestedCallWithCallback() QCOMPARE(signalsReceived, 1); } +class RaceConditionSignalWaiter : public QObject +{ + Q_OBJECT +public: + int count; + RaceConditionSignalWaiter() : count (0) {} + virtual ~RaceConditionSignalWaiter() {} + +public slots: + void countUp() { ++count; emit done(); } +signals: + void done(); +}; + +void tst_QDBusConnection::serviceRegistrationRaceCondition() +{ + // There was a race condition in the updating of list of name owners in + // QtDBus. When the user connects to a signal coming from a given + // service, we must listen for NameOwnerChanged signals relevant to that + // name and update when the owner changes. However, it's possible that we + // receive in one chunk from the server both the NameOwnerChanged signal + // about the service and the signal we're interested in. Since QtDBus + // posts events in order to handle the incoming signals, the update + // happens too late. + + const QString connectionName = "testConnectionName"; + const QString serviceName = "org.example.SecondaryName"; + + QDBusConnection session = QDBusConnection::sessionBus(); + QVERIFY(!session.interface()->isServiceRegistered(serviceName)); + + // connect to the signal: + RaceConditionSignalWaiter recv; + session.connect(serviceName, "/", "com.trolltech.TestCase", "oneSignal", &recv, SLOT(countUp())); + + // create a secondary connection and register a name + QDBusConnection connection = QDBusConnection::connectToBus(QDBusConnection::SessionBus, connectionName); + QDBusConnection::disconnectFromBus(connectionName); // disconnection happens when "connection" goes out of scope + QVERIFY(connection.isConnected()); + QVERIFY(connection.registerService(serviceName)); + + // send a signal + QDBusMessage msg = QDBusMessage::createSignal("/", "com.trolltech.TestCase", "oneSignal"); + connection.send(msg); + + // make a blocking call just to be sure that the buffer was flushed + msg = QDBusMessage::createMethodCall("org.freedesktop.DBus", "/org/freedesktop/DBus", "org.freedesktop.DBus", + "NameHasOwner"); + msg << connectionName; + connection.call(msg); // ignore result + + // Now here's the race condition (more info on task QTBUG-15651): + // the bus has most likely queued three signals for us to work on: + // 1) NameOwnerChanged for the connection we created above + // 2) NameOwnerChanged for the service we registered above + // 3) The "oneSignal" signal we sent + // + // We'll most likely receive all three in one go from the server. We must + // update the owner of serviceName before we start processing the + // "oneSignal" signal. + + QTestEventLoop::instance().connect(&recv, SIGNAL(done()), SLOT(exitLoop())); + QTestEventLoop::instance().enterLoop(1); + QVERIFY(!QTestEventLoop::instance().timeout()); + QCOMPARE(recv.count, 1); +} + QString MyObject::path; QTEST_MAIN(tst_QDBusConnection) |