VST3: Use a proxy for connecting and passing messages #8481

This separates channels in each direction component <> controller,
preventing recursions.

libs/ardour/ardour/vst3_host.h

@@ -198,6 +198,28 @@ protected:
 	boost::shared_ptr<HostAttributeList> _attribute_list;
 };
 
+class LIBARDOUR_API ConnectionProxy : public Vst::IConnectionPoint, public RefObject
+{
+public:
+	ConnectionProxy (IConnectionPoint* src);
+	~ConnectionProxy () SMTG_OVERRIDE;
+
+	QUERY_INTERFACE_IMPL (Vst::IConnectionPoint);
+	uint32 PLUGIN_API addRef () SMTG_OVERRIDE { return RefObject::addRef (); }
+	uint32 PLUGIN_API release () SMTG_OVERRIDE { return RefObject::release (); }
+
+	/* IConnectionPoint API */
+	tresult PLUGIN_API connect (Vst::IConnectionPoint*) SMTG_OVERRIDE;
+	tresult PLUGIN_API disconnect (Vst::IConnectionPoint*) SMTG_OVERRIDE;
+	tresult PLUGIN_API notify (Vst::IMessage*) SMTG_OVERRIDE;
+
+	bool disconnect ();
+
+protected:
+	IConnectionPoint* _src;
+	IConnectionPoint* _dst;
+};
+
 class LIBARDOUR_API PlugInterfaceSupport : public Vst::IPlugInterfaceSupport
 {
 public:

libs/ardour/ardour/vst3_plugin.h

@@ -54,7 +54,6 @@ namespace Steinberg {
 class LIBARDOUR_API VST3PI
 	: public Vst::IComponentHandler
 	, public Vst::IComponentHandler2
-	, public Vst::IConnectionPoint
 	, public Vst::IUnitHandler
 	, public IPlugFrame
 	, public Presonus::IContextInfoProvider3
@@ -75,11 +74,6 @@ public:
 	tresult PLUGIN_API startGroupEdit () SMTG_OVERRIDE;
 	tresult PLUGIN_API finishGroupEdit () SMTG_OVERRIDE;
 
-	/* IConnectionPoint API */
-	tresult PLUGIN_API connect (Vst::IConnectionPoint* other) SMTG_OVERRIDE;
-	tresult PLUGIN_API disconnect (Vst::IConnectionPoint* other) SMTG_OVERRIDE;
-	tresult PLUGIN_API notify (Vst::IMessage* message) SMTG_OVERRIDE;
-
 	/* IPlugFrame */
 	tresult PLUGIN_API resizeView (IPlugView* view, ViewRect* newSize) SMTG_OVERRIDE;
 
@@ -217,7 +211,8 @@ private:
 
 	boost::shared_ptr<ARDOUR::VST3PluginModule> _module;
 
-	std::vector <Vst::IConnectionPoint*> _connections;
+	boost::shared_ptr<ConnectionProxy> _component_cproxy;
+	boost::shared_ptr<ConnectionProxy> _controller_cproxy;
 
 	FUID                  _fuid;
 	Vst::IComponent*      _component;

libs/ardour/vst3_host.cc

@@ -299,6 +299,90 @@ HostMessage::getAttributes ()
 
 /* ****************************************************************************/
 
+ConnectionProxy::ConnectionProxy (Vst::IConnectionPoint* src)
+	: _src (src)
+	, _dst (0)
+{
+	if (_src) {
+		_src->addRef ();
+	}
+}
+
+ConnectionProxy::~ConnectionProxy ()
+{
+	if (_src) {
+		_src->release ();
+	}
+	if (_dst) {
+		_dst->release ();
+	}
+}
+
+tresult
+ConnectionProxy::connect (Vst::IConnectionPoint* dst)
+{
+	if (!dst) {
+		return kInvalidArgument;
+	}
+	if (_dst) {
+		return kResultFalse;
+	}
+
+	_dst = dst;
+	_dst->addRef ();
+
+	tresult res = _src->connect (this);
+
+	if (res != kResultTrue) {
+		_dst->release ();
+		_dst = 0;
+	}
+	return res;
+}
+
+tresult
+ ConnectionProxy::disconnect (Vst::IConnectionPoint* dst)
+{
+  if (!dst) {
+    return kInvalidArgument;
+	}
+
+  if (dst != _dst) {
+		return kInvalidArgument;
+	}
+
+	if (_src) {
+		_src->disconnect (this);
+	}
+
+	_dst->release ();
+	_dst = 0;
+	return kResultTrue;
+}
+
+
+tresult
+ConnectionProxy::notify (Vst::IMessage* message)
+{
+  if (!_dst) {
+		return kResultFalse;
+	}
+#if 0
+	if (strcmp ("ArdourGUI",  pthread_name ())) {
+		return kResultFalse;
+	}
+#endif
+	return _dst->notify (message);
+}
+
+bool
+ConnectionProxy::disconnect ()
+{
+  return kResultTrue == disconnect (_dst);
+}
+
+/* ****************************************************************************/
+
 PlugInterfaceSupport::PlugInterfaceSupport ()
 {
 	using namespace Vst;

libs/ardour/vst3_plugin.cc

@@ -1232,14 +1232,18 @@ VST3PI::connect_components ()
 		return true;
 	}
 
-	tresult res = componentCP->connect (this);
+	_component_cproxy = boost::shared_ptr<ConnectionProxy> (new ConnectionProxy (componentCP));
+	_controller_cproxy = boost::shared_ptr<ConnectionProxy> (new ConnectionProxy (controllerCP));
+
+	tresult res = _component_cproxy->connect (controllerCP);
 	if (!(res == kResultOk || res == kNotImplemented)) {
-		return false;
+		DEBUG_TRACE (DEBUG::VST3Config, "VST3PI::connect_components Cannot connect controller to component\n");
+		//return false;
 	}
 
-	res = controllerCP->connect (this);
+	res = _controller_cproxy->connect (componentCP);
 	if (!(res == kResultOk || res == kNotImplemented)) {
-		DEBUG_TRACE (DEBUG::VST3Config, "VST3PI::connect_components Cannot connect controller, ignored.\n");
+		DEBUG_TRACE (DEBUG::VST3Config, "VST3PI::connect_components Cannot connect component to controller\n");
 	}
 
 	return true;
@@ -1248,60 +1252,17 @@ VST3PI::connect_components ()
 bool
 VST3PI::disconnect_components ()
 {
-	FUnknownPtr<Vst::IConnectionPoint> componentCP (_component);
+	if (!_component_cproxy || !_controller_cproxy) {
-	FUnknownPtr<Vst::IConnectionPoint> controllerCP (_controller);
-	if (!componentCP || !controllerCP) {
 		return false;
 	}
 
-	bool res = kResultTrue == componentCP->disconnect (this);
+	bool rv = _component_cproxy->disconnect ();
-	res &= kResultTrue == controllerCP->disconnect (this);
+	rv &= _controller_cproxy->disconnect ();
-	return res;
-}
 
-tresult
+	_component_cproxy.reset ();
-VST3PI::connect (Vst::IConnectionPoint* other)
+	_controller_cproxy.reset ();
-{
-	if (!other) {
-		return kInvalidArgument;
-	}
-	_connections.push_back (other);
-	return kResultTrue;
-}
 
-tresult
+	return rv;
-VST3PI::disconnect (Vst::IConnectionPoint* other)
-{
-	std::vector <Vst::IConnectionPoint*>::iterator i = std::find (_connections.begin(), _connections.end(), other);
-	if (i != _connections.end()) {
-		_connections.erase (i);
-		return kResultTrue;
-	}
-	return kInvalidArgument;
-}
-
-tresult
-VST3PI::notify (Vst::IMessage* msg)
-{
-	DEBUG_TRACE (DEBUG::VST3Callbacks, "VST3PI::notify.\n");
-	for (std::vector <Vst::IConnectionPoint*>::const_iterator i = _connections.begin(); i != _connections.end(); ++i) {
-		/* TODO delegate to GUI thread if available
-		 * see ./libs/pbd/pbd/event_loop.h ir->call_slot ()
-		 * and HostMessage()
-		 */
-		(*i)->notify (msg);
-	}
-
-	FUnknownPtr<Vst::IConnectionPoint> componentCP (_component);
-	FUnknownPtr<Vst::IConnectionPoint> controllerCP (_controller);
-	if (componentCP) {
-		componentCP->notify (msg);
-	}
-	if (controllerCP) {
-		controllerCP->notify (msg);
-	}
-
-	return kResultTrue;
 }
 
 tresult
@@ -1311,7 +1272,6 @@ VST3PI::queryInterface (const TUID _iid, void** obj)
 	QUERY_INTERFACE (_iid, obj, Vst::IComponentHandler::iid, Vst::IComponentHandler)
 	QUERY_INTERFACE (_iid, obj, Vst::IComponentHandler2::iid, Vst::IComponentHandler2)
 
-	QUERY_INTERFACE (_iid, obj, Vst::IConnectionPoint::iid, Vst::IConnectionPoint)
 	QUERY_INTERFACE (_iid, obj, Vst::IUnitHandler::iid, Vst::IUnitHandler)
 
 	QUERY_INTERFACE (_iid, obj, Presonus::IContextInfoProvider::iid, Presonus::IContextInfoProvider)