Disconnect Signals before dropping ports

significantly speeds up session close

libs/ardour/ardour/port.h

@@ -125,6 +125,7 @@ public:
 	PBD::Signal1<void,bool> MonitorInputChanged;
 	static PBD::Signal2<void,boost::shared_ptr<Port>,boost::shared_ptr<Port> > PostDisconnect;
 	static PBD::Signal0<void> PortDrop;
+	static PBD::Signal0<void> PortSignalDrop;
 
 	static void set_cycle_framecnt (pframes_t n) {
 		_cycle_nframes = n;
@@ -170,6 +171,7 @@ private:
 	std::set<std::string> _connections;
 
 	void port_connected_or_disconnected (boost::weak_ptr<Port>, boost::weak_ptr<Port>, bool);
+	void signal_drop ();
 	void drop ();
 	PBD::ScopedConnection drop_connection;
 	PBD::ScopedConnection engine_connection;

libs/ardour/port.cc

@@ -38,6 +38,7 @@ using namespace PBD;
 
 PBD::Signal2<void,boost::shared_ptr<Port>, boost::shared_ptr<Port> > Port::PostDisconnect;
 PBD::Signal0<void> Port::PortDrop;
+PBD::Signal0<void> Port::PortSignalDrop;
 
 bool         Port::_connecting_blocked = false;
 pframes_t    Port::_global_port_buffer_offset = 0;
@@ -75,6 +76,7 @@ Port::Port (std::string const & n, DataType t, PortFlags f)
 	}
 
 	PortDrop.connect_same_thread (drop_connection, boost::bind (&Port::drop, this));
+	PortSignalDrop.connect_same_thread (drop_connection, boost::bind (&Port::signal_drop, this));
 	port_manager->PortConnectedOrDisconnected.connect_same_thread (engine_connection,
 			boost::bind (&Port::port_connected_or_disconnected, this, _1, _3, _5));
 }
@@ -118,6 +120,12 @@ Port::set_pretty_name(const std::string& n)
 	return false;
 }
 
+void
+Port::signal_drop ()
+{
+	engine_connection.disconnect ();
+}
+
 void
 Port::drop ()
 {

libs/ardour/session.cc

@@ -591,6 +591,9 @@ Session::destroy ()
 
 	_state_of_the_state = StateOfTheState (CannotSave|Deletion);
 
+	/* stop autoconnecting */
+	auto_connect_thread_terminate ();
+
 	/* disconnect from any and all signals that we are connected to */
 
 	drop_connections ();
@@ -613,6 +616,7 @@ Session::destroy ()
 	 * callbacks from the engine any more.
 	 */
 
+	Port::PortSignalDrop (); /* EMIT SIGNAL */
 	Port::PortDrop (); /* EMIT SIGNAL */
 
 	ltc_tx_cleanup();
@@ -725,8 +729,6 @@ Session::destroy ()
 	pthread_cond_destroy (&_rt_emit_cond);
 	pthread_mutex_destroy (&_rt_emit_mutex);
 
-	auto_connect_thread_terminate ();
-
 	pthread_cond_destroy (&_auto_connect_cond);
 	pthread_mutex_destroy (&_auto_connect_mutex);
 
@@ -6791,12 +6793,12 @@ Session::auto_connect_thread_start ()
 	if (_ac_thread_active) {
 		return;
 	}
-	_ac_thread_active = true;
+
-	// clear queue
 	while (!_auto_connect_queue.empty ()) {
 		_auto_connect_queue.pop ();
 	}
 
+	_ac_thread_active = true;
 	if (pthread_create (&_auto_connect_thread, NULL, auto_connect_thread, this)) {
 		_ac_thread_active = false;
 	}
@@ -6810,6 +6812,13 @@ Session::auto_connect_thread_terminate ()
 	}
 	_ac_thread_active = false;
 
+	{
+		Glib::Threads::Mutex::Lock lx (_auto_connect_queue_lock);
+		while (!_auto_connect_queue.empty ()) {
+			_auto_connect_queue.pop ();
+		}
+	}
+
 	if (pthread_mutex_lock (&_auto_connect_mutex) == 0) {
 		pthread_cond_signal (&_auto_connect_cond);
 		pthread_mutex_unlock (&_auto_connect_mutex);