Make sure we don't deadlock when connecting signals

This commit moves the code that finishes the signal-slot connection into
the QtDBus auxiliary thread. That is necessary because we're holding the
lock for writing while making blocking calls. The auxiliary thread might
be waiting for us to release that lock while processing some previous
message.

Change-Id: Iee8cbc07c4434ce9b560ffff13d0521b94a51833
Reviewed-by: Albert Astals Cid <aacid@kde.org>
Reviewed-by: Alex Blasche <alexander.blasche@theqtcompany.com>

1 files changed, 6 insertions, 2 deletions

diff --git a/src/dbus/qdbusconnection_p.h b/src/dbus/qdbusconnection_p.h
index 5f7f58e549..e12b77837e 100644
--- a/src/dbus/qdbusconnection_p.h
+++ b/src/dbus/qdbusconnection_p.h
@@ -213,8 +213,6 @@ public:
     bool connectSignal(const QString &service, const QString &path, const QString& interface,
                        const QString &name, const QStringList &argumentMatch, const QString &signature,
                        QObject *receiver, const char *slot);
-    void connectSignal(const QString &key, const SignalHook &hook);
-    SignalHookHash::Iterator disconnectSignal(SignalHookHash::Iterator &it);
     bool disconnectSignal(const QString &service, const QString &path, const QString& interface,
                           const QString &name, const QStringList &argumentMatch, const QString &signature,
                           QObject *receiver, const char *slot);
@@ -254,6 +252,8 @@ private:
     void deliverCall(QObject *object, int flags, const QDBusMessage &msg,
                      const QVector<int> &metaTypes, int slotIdx);
 
+    SignalHookHash::Iterator removeSignalHookNoLock(SignalHookHash::Iterator it);
+
     bool isServiceRegisteredByThread(const QString &serviceName);
 
     QString getNameOwnerNoCache(const QString &service);
@@ -270,6 +270,8 @@ public slots:
     void socketWrite(int);
     void objectDestroyed(QObject *o);
     void relaySignal(QObject *obj, const QMetaObject *, int signalId, const QVariantList &args);
+    void addSignalHook(const QString &key, const SignalHook &hook);
+    bool removeSignalHook(const QString &key, const SignalHook &hook);
 
 private slots:
     void serviceOwnerChangedNoLock(const QString &name, const QString &oldOwner, const QString &newOwner);
@@ -279,6 +281,8 @@ private slots:
 signals:
     void dispatchStatusChanged();
     void messageNeedsSending(QDBusPendingCallPrivate *pcall, void *msg, int timeout = -1);
+    void signalNeedsConnecting(const QString &key, const QDBusConnectionPrivate::SignalHook &hook);
+    bool signalNeedsDisconnecting(const QString &key, const QDBusConnectionPrivate::SignalHook &hook);
     void serviceOwnerChanged(const QString &name, const QString &oldOwner, const QString &newOwner);
     void callWithCallbackFailed(const QDBusError &error, const QDBusMessage &message);
     void newServerConnection(QDBusConnectionPrivate *newConnection);