cleanup up cleanup at session destruction; clarify the meaning of 3 signals (DropReferences & Destroyed in libardour ; CatchDeletion in the GTK UI); clarify ownership of objects (session no longer pays attention to DropReferences for objects that it is considered to own, such as routes, sources, etc); fix up MIDI parsing and a couple of other places by correcting syntax for return of values from a boost::signals2::signal (possible danger elsewhere to be checked)

git-svn-id: svn://localhost/ardour2/branches/3.0@6389 d708f5d6-7413-0410-9779-e7cbd77b26cf

gtk2_ardour/ardour_ui.cc

@@ -898,7 +898,7 @@ ARDOUR_UI::every_point_zero_one_seconds ()
 }
 
 void
-ARDOUR_UI::update_sample_rate (nframes_t ignored)
+ARDOUR_UI::update_sample_rate (nframes_t)
 {
 	char buf[32];
 

gtk2_ardour/audio_region_view.cc

@@ -1186,7 +1186,7 @@ AudioRegionView::add_ghost (TimeAxisView& tv)
 	ghost->set_colors();
 	ghosts.push_back (ghost);
 
-	ghost->GoingAway.connect (*this, ui_bind (&RegionView::remove_ghost, this, _1), gui_context());
+	ghost->CatchDeletion.connect (*this, ui_bind (&RegionView::remove_ghost, this, _1), gui_context());
 
 	return ghost;
 }

gtk2_ardour/audio_streamview.cc

@@ -190,7 +190,7 @@ AudioStreamView::add_region_view_internal (boost::shared_ptr<Region> r, bool wai
 
 	/* catch region going away */
 
-	r->GoingAway.connect (*this, boost::bind (&AudioStreamView::remove_region_view, this, boost::weak_ptr<Region> (r)), gui_context());
+	r->DropReferences.connect (*this, boost::bind (&AudioStreamView::remove_region_view, this, boost::weak_ptr<Region> (r)), gui_context());
 
 	RegionViewAdded (region_view);
 

gtk2_ardour/automation_streamview.cc

@@ -129,7 +129,7 @@ AutomationStreamView::add_region_view_internal (boost::shared_ptr<Region> region
 	display_region(region_view);
 
 	/* catch regionview going away */
-	region->GoingAway.connect (*this, boost::bind (&AutomationStreamView::remove_region_view, this, boost::weak_ptr<Region>(region)), gui_context());
+	region->DropReferences.connect (*this, boost::bind (&AutomationStreamView::remove_region_view, this, boost::weak_ptr<Region>(region)), gui_context());
 
 	RegionViewAdded (region_view);
 

gtk2_ardour/axis_view.cc

@@ -44,6 +44,7 @@ using namespace Gtkmm2ext;
 using namespace ARDOUR;
 
 list<Gdk::Color> AxisView::used_colors;
+PBD::Signal1<void,AxisView*> AxisView::CatchDeletion;
 
 AxisView::AxisView (ARDOUR::Session* sess) 
 	: SessionHandlePtr (sess)
@@ -54,7 +55,6 @@ AxisView::AxisView (ARDOUR::Session* sess)
 
 AxisView::~AxisView()
 {
-
 }
 
 Gdk::Color

gtk2_ardour/axis_view.h

@@ -26,7 +26,7 @@
 #include <gdkmm/color.h>
 
 #include "pbd/xml++.h"
-#include "pbd/destructible.h"
+#include "pbd/signals.h"
 
 #include "ardour/session_handle.h"
 
@@ -41,7 +41,7 @@ namespace ARDOUR {
  * AxisView defines the abstract base class for time-axis trackviews and routes.
  *
  */
-class AxisView : public virtual Selectable, public PBD::Destructible, public PBD::ScopedConnectionList, public ARDOUR::SessionHandlePtr
+class AxisView : public virtual Selectable, public PBD::ScopedConnectionList, public ARDOUR::SessionHandlePtr
 {
   public:
 	/**
@@ -60,6 +60,8 @@ class AxisView : public virtual Selectable, public PBD::Destructible, public PBD
 		_marked_for_display = yn;
 	}
 	
+	static PBD::Signal1<void,AxisView*> CatchDeletion;
+
 	sigc::signal<void> Hiding;
 
 	void set_old_order_key (uint32_t ok) { _old_order_key = ok; }

gtk2_ardour/crossfade_view.cc

@@ -40,7 +40,7 @@ using namespace Editing;
 using namespace Gnome;
 using namespace Canvas;
 
-PBD::Signal1<void,CrossfadeView*> CrossfadeView::GoingAway;
+PBD::Signal1<void,CrossfadeView*> CrossfadeView::CatchDeletion;
 
 CrossfadeView::CrossfadeView (ArdourCanvas::Group *parent,
 			      RouteTimeAxisView &tv,
@@ -90,7 +90,7 @@ CrossfadeView::CrossfadeView (ArdourCanvas::Group *parent,
 
 CrossfadeView::~CrossfadeView ()
 {
-	 GoingAway (this) ; /* EMIT_SIGNAL */
+	 CatchDeletion (this) ; /* EMIT_SIGNAL */
 }
 
 void

gtk2_ardour/crossfade_view.h

@@ -52,7 +52,7 @@ struct CrossfadeView : public TimeAxisViewItem
     bool visible() const { return _visible; }
     void set_valid (bool yn);
 
-    static PBD::Signal1<void,CrossfadeView*> GoingAway;
+    static PBD::Signal1<void,CrossfadeView*> CatchDeletion;
 
     AudioRegionView& upper_regionview () const;
 

gtk2_ardour/editor.cc

@@ -4804,7 +4804,7 @@ Editor::handle_new_route (RouteList& routes)
 		rtv->view()->RegionViewAdded.connect (sigc::mem_fun (*this, &Editor::region_view_added));
 		rtv->view()->HeightChanged.connect (sigc::mem_fun (*this, &Editor::streamview_height_changed));
 
-		rtv->GoingAway.connect (*this, boost::bind (&Editor::remove_route, this, rtv), gui_context());
+		route->DropReferences.connect (*this, boost::bind (&Editor::remove_route, this, rtv), gui_context());
 	}
 
 	_routes->routes_added (new_views);
@@ -4833,6 +4833,8 @@ Editor::remove_route (TimeAxisView *tv)
 		
 	TimeAxisView* next_tv = 0;
 
+	_routes->route_removed (tv);
+
 	if (tv == entered_track) {
 		entered_track = 0;
 	}
@@ -4862,6 +4864,7 @@ Editor::remove_route (TimeAxisView *tv)
                        ActionManager::uncheck_toggleaction ("<Actions>/Editor/show-editor-mixer");
                }
 	}
+
 }
 
 void

gtk2_ardour/editor_imageframe.cc

@@ -169,11 +169,6 @@ Editor::popup_marker_time_axis_edit_menu(int button, int32_t time, ArdourCanvas:
 }
 /* </CMT Additions file="editor.cc"> */
 
-
-
-
-
-
 /* <CMT Additions file="editor_canvas_events.cc"> */
 bool
 Editor::canvas_imageframe_item_view_event (GdkEvent *event, ArdourCanvas::Item* item, ImageFrameView *ifv)
@@ -1093,7 +1088,7 @@ Editor::handle_new_imageframe_time_axis_view(const string & track_name, void* sr
 	row[route_display_columns.tv] = iftav;
 	route_list_display.get_selection()->select (row);
 
-	iftav->GoingAway.connect (*this, boost::bind (&Editor::remove_route, this, (TimeAxisView*)iftav), gui_context());
+	iftav->CatchDeletion.connect (*this, boost::bind (&Editor::remove_route, this, (TimeAxisView*)iftav), gui_context());
 	iftav->gui_changed.connect(sigc::mem_fun(*this, &Editor::handle_gui_changes)) ;
 }
 
@@ -1110,7 +1105,7 @@ Editor::handle_new_imageframe_marker_time_axis_view(const string & track_name, T
 	row[route_display_columns.tv] = mta;
 	route_list_display.get_selection()->select (row);
 
-	mta->GoingAway.connect (*this, boost::bind (&Editor::remove_route, this, (TimeAxisView*)mta), gui_context());
+	mta->CatchDeletion.connect (*this, boost::bind (&Editor::remove_route, this, (TimeAxisView*)mta), gui_context());
  }
 
 

gtk2_ardour/editor_markers.cc

@@ -165,7 +165,7 @@ Editor::location_changed (Location *location)
 }
 
 void
-Editor::location_flags_changed (Location *location, void *src)
+Editor::location_flags_changed (Location *location, void*)
 {
 	ENSURE_GUI_THREAD (*this, &Editor::location_flags_changed, location, src)
 
@@ -338,7 +338,7 @@ Editor::refresh_location_display ()
 }
 
 void
-Editor::refresh_location_display_s (Change ignored)
+Editor::refresh_location_display_s (Change)
 {
 	ENSURE_GUI_THREAD (*this, &Editor::refresh_location_display_s, ignored)
 

gtk2_ardour/editor_mixer.cc

@@ -169,7 +169,7 @@ Editor::create_editor_mixer ()
 					      _session,
 					      false);
 	current_mixer_strip->Hiding.connect (sigc::mem_fun(*this, &Editor::current_mixer_strip_hidden));
-	current_mixer_strip->GoingAway.connect (*this, boost::bind (&Editor::current_mixer_strip_removed, this), gui_context());
+	current_mixer_strip->CatchDeletion.connect (*this, boost::bind (&Editor::current_mixer_strip_removed, this), gui_context());
 #ifdef GTKOSX
 	current_mixer_strip->WidthChanged.connect (sigc::mem_fun(*this, &Editor::ensure_all_elements_drawn));
 #endif
@@ -349,16 +349,17 @@ Editor::session_going_away ()
 
 	playhead_cursor->canvas_item.hide ();
 
-	/* hide all tracks */
-
-	_routes->hide_all_tracks (false);
-
 	/* rip everything out of the list displays */
 
 	_regions->clear ();
 	_routes->clear ();
 	_route_groups->clear ();
 
+	for (TrackViewList::iterator i = track_views.begin(); i != track_views.end(); ++i) {
+		delete *i;
+	}
+	track_views.clear ();
+
 	zoom_range_clock.set_session (0);
 	nudge_clock.set_session (0);
 

gtk2_ardour/editor_route_groups.cc

@@ -610,7 +610,7 @@ EditorRouteGroups::groups_changed ()
 }
 
 void
-EditorRouteGroups::flags_changed (void* src, RouteGroup* group)
+EditorRouteGroups::flags_changed (void*, RouteGroup* group)
 {
         ENSURE_GUI_THREAD (*this, &EditorRouteGroups::flags_changed, src, group)
 

gtk2_ardour/editor_routes.cc

@@ -327,6 +327,10 @@ EditorRoutes::redisplay ()
 void
 EditorRoutes::route_deleted (Gtk::TreeModel::Path const &)
 {
+	if (!_session || _session->deletion_in_progress()) {
+		return;
+	}
+		
         /* this could require an order reset & sync */
 	_session->set_remote_control_ids();
 	_ignore_reorder = true;
@@ -334,10 +338,13 @@ EditorRoutes::route_deleted (Gtk::TreeModel::Path const &)
 	_ignore_reorder = false;
 }
 
-
 void
 EditorRoutes::visible_changed (Glib::ustring const & path)
 {
+	if (_session && _session->deletion_in_progress()) {
+		return;
+	}
+
 	TreeIter iter;
 
 	if ((iter = _model->get_iter (path))) {
@@ -385,7 +392,6 @@ EditorRoutes::routes_added (list<RouteTimeAxisView*> routes)
 
 		(*x)->route()->gui_changed.connect (*this, ui_bind (&EditorRoutes::handle_gui_changes, this, _1, _2), gui_context());
 		(*x)->route()->NameChanged.connect (*this, boost::bind (&EditorRoutes::route_name_changed, this, wr), gui_context());
-		(*x)->GoingAway.connect (*this, boost::bind (&EditorRoutes::route_removed, this, *x), gui_context());
 
 		if ((*x)->is_track()) {
 			boost::shared_ptr<Track> t = boost::dynamic_pointer_cast<Track> ((*x)->route());
@@ -403,7 +409,7 @@ EditorRoutes::routes_added (list<RouteTimeAxisView*> routes)
 }
 
 void
-EditorRoutes::handle_gui_changes (string const & what, void *src)
+EditorRoutes::handle_gui_changes (string const & what, void*)
 {
 	ENSURE_GUI_THREAD (*this, &EditorRoutes::handle_gui_changes, what, src)
 

gtk2_ardour/editor_routes.h

@@ -49,6 +49,7 @@ public:
 	void redisplay ();
 	void update_visibility ();
 	void routes_added (std::list<RouteTimeAxisView*> routes);
+	void route_removed (TimeAxisView *);
 	void hide_track_in_display (TimeAxisView &);
 	std::list<TimeAxisView*> views () const;
 	void hide_all_tracks (bool);
@@ -69,7 +70,6 @@ private:
 	void reordered (Gtk::TreeModel::Path const &, Gtk::TreeModel::iterator const &, int *);
 	bool button_press (GdkEventButton *);
 	void route_name_changed (boost::weak_ptr<ARDOUR::Route>);
-	void route_removed (TimeAxisView *);
 	void handle_gui_changes (std::string const &, void *);
 	void update_rec_display ();
 	void update_mute_display ();

gtk2_ardour/editor_selection_list.cc

@@ -51,11 +51,11 @@ Editor::handle_new_named_selection ()
 }
 
 void
-Editor::add_named_selection_to_named_selection_display (NamedSelection& selection)
+Editor::add_named_selection_to_named_selection_display (boost::shared_ptr<NamedSelection> selection)
 {
         TreeModel::Row row = *(named_selection_model->append());
 	row[named_selection_columns.text] = selection.name;
-	row[named_selection_columns.selection] = &selection;
+	row[named_selection_columns.selection] = selection;
 }
 
 void
@@ -195,13 +195,14 @@ Editor::create_named_selection ()
 			return;
 		}
 
-		new NamedSelection (name, thelist); // creation will add it to the model
+		boost::shared_ptr<NamedSelection> ns (new NamedSelection (name, thelist));
 		
 		/* make the one we just added be selected */
 
 		TreeModel::Children::iterator added = named_selection_model->children().end();
 		--added;
 		named_selection_display.get_selection()->select (*added);
+
 	} else {
 		error << _("No selectable material found in the currently selected time range") << endmsg;
 	}

gtk2_ardour/editor_tempodisplay.cc

@@ -99,10 +99,11 @@ Editor::tempo_map_changed (Change ignored)
 		return;
 	}
 
-	ENSURE_GUI_THREAD (*this, &Editor::tempo_map_changed, ignored)
+	ENSURE_GUI_THREAD (*this, &Editor::tempo_map_changed ignored);
 
-	if (tempo_lines)
+	if (tempo_lines) {
 		tempo_lines->tempo_map_changed();
+	}
 
 	compute_current_bbt_points(leftmost_frame, leftmost_frame + current_page_frames());
 	_session->tempo_map().apply_with_metrics (*this, &Editor::draw_metric_marks); // redraw metric markers

gtk2_ardour/ghostregion.cc

@@ -34,7 +34,7 @@ using namespace Editing;
 using namespace ArdourCanvas;
 using namespace ARDOUR;
 
-PBD::Signal1<void,GhostRegion*> GhostRegion::GoingAway;
+PBD::Signal1<void,GhostRegion*> GhostRegion::CatchDeletion;
 
 GhostRegion::GhostRegion (ArdourCanvas::Group* parent, TimeAxisView& tv, TimeAxisView& source_tv, double initial_pos)
 	: trackview (tv)
@@ -63,7 +63,7 @@ GhostRegion::GhostRegion (ArdourCanvas::Group* parent, TimeAxisView& tv, TimeAxi
 
 GhostRegion::~GhostRegion ()
 {
-	GoingAway (this);
+	CatchDeletion (this);
 	delete base_rect;
 	delete group;
 }

gtk2_ardour/ghostregion.h

@@ -57,7 +57,7 @@ public:
 	ArdourCanvas::Group* group;
 	ArdourCanvas::SimpleRect* base_rect;
 
-	static PBD::Signal1<void,GhostRegion*> GoingAway;
+	static PBD::Signal1<void,GhostRegion*> CatchDeletion;
 };
 
 class AudioGhostRegion : public GhostRegion {

gtk2_ardour/gui_thread.h

@@ -20,15 +20,12 @@
 #ifndef __ardour_gtk_gui_thread_h__
 #define __ardour_gtk_gui_thread_h__
 
+#include <cstdlib>
 #include <gtkmm2ext/gtk_ui.h>
 #include <boost/bind.hpp>
 #include <boost/bind/protect.hpp>
 
-#define ENSURE_GUI_THREAD(obj,method, ...) \
+#define ENSURE_GUI_THREAD(obj,method, ...) if (!Gtkmm2ext::UI::instance()->caller_is_self()) { abort (); } 
-     if (!Gtkmm2ext::UI::instance()->caller_is_self()) { \
-	     Gtkmm2ext::UI::instance()->call_slot (boost::bind ((method), &(obj), ## __VA_ARGS__)); \
-        return;\
-     }
 
 #define gui_context() Gtkmm2ext::UI::instance() /* a UICallback-derived object that specifies the event loop for GUI signal handling */
 #define ui_bind(f, ...) boost::protect (boost::bind (f, __VA_ARGS__))

gtk2_ardour/imageframe_time_axis.cc

@@ -89,7 +89,7 @@ ImageFrameTimeAxis::ImageFrameTimeAxis(const string & track_id, PublicEditor& ed
  */
 ImageFrameTimeAxis::~ImageFrameTimeAxis ()
 {
-	 GoingAway ; /* EMIT_SIGNAL */
+	CatchDeletion (this);
 
 	// Destroy all the marker views we may have associaited with this TimeAxis
 	for(MarkerTimeAxisList::iterator iter = marker_time_axis_list.begin(); iter != marker_time_axis_list.end(); ++iter)
@@ -322,7 +322,7 @@ ImageFrameTimeAxis::add_marker_time_axis(MarkerTimeAxis* marker_track, void* src
 	else
 	{
 		marker_time_axis_list.push_back(marker_track) ;
-		marker_track->GoingAway.connect (*this, boost::bind (&ImageFrameTimeAxis::remove_time_axis_view, this, marker_track, (void*)this), gui_context());
+		marker_track->CatchDeletion.connect (*this, boost::bind (&ImageFrameTimeAxis::remove_time_axis_view, this, marker_track, (void*)this), gui_context());
 
 		 MarkerTimeAxisAdded(marker_track, src) ; /* EMIT_SIGNAL */
 		ret = true ;

gtk2_ardour/imageframe_time_axis_group.cc

@@ -35,6 +35,8 @@
 
 using namespace ARDOUR ;
 
+PBD::Signal1<void,ImageFrameTimeAxisGroup*> ImageFrameTimeAxisGroup::CatchDeletion;
+
 //---------------------------------------------------------------------------------------//
 // Constructor / Desctructor
 
@@ -74,7 +76,7 @@ ImageFrameTimeAxisGroup::~ImageFrameTimeAxisGroup()
 		iter = next ;
 	}
 
-	 GoingAway ; /* EMIT_SIGNAL */
+	 CatchDeletion ; /* EMIT_SIGNAL */
 }
 
 
@@ -216,7 +218,7 @@ ImageFrameTimeAxisGroup::add_imageframe_item(const string & frame_id, nframes_t
 
 		imageframe_views.push_front(ifv) ;
 
-		ifv->GoingAway.connect (*this, boost::bind (&ImageFrameTimeAxisGroup::remove_imageframe_item, this, (void*)this), gui_context());
+		ifv->CatchDeletion.connect (*this, boost::bind (&ImageFrameTimeAxisGroup::remove_imageframe_item, this, (void*)this), gui_context());
 
 		 ImageFrameAdded(ifv, src) ; /* EMIT_SIGNAL */
 	}

gtk2_ardour/imageframe_time_axis_group.h

@@ -235,11 +235,11 @@ class ImageFrameTimeAxisGroup : public sigc::trackable
 		//---------------------------------------------------------------------------------//
 		// Emitted Signals
 
-		sigc::signal<void> GoingAway ;
+		static sigc::signal<void,ImageFrameTimeAxisGroup*> CatchDeletion;
 
 		/**
 		 * Emitted when this Group has been removed
-		 * This is different to the GoingAway signal in that this signal
+		 * This is different to the CatchDeletion signal in that this signal
 		 * is emitted during the deletion of this Time Axis, and not during
 		 * the destructor, this allows us to capture the source of the deletion
 		 * event

gtk2_ardour/imageframe_time_axis_view.cc

@@ -214,7 +214,7 @@ ImageFrameTimeAxisView::add_imageframe_group(std::string group_id, void* src)
 
 		imageframe_groups.push_front(iftag) ;
 
-		iftag->GoingAway.connect (*this, boost::bind (&ImageFrameTimeAxisView::remove_imageframe_group, this, iftag, (void*)this), gui_context());
+		iftag->CatchDeletion.connect (*this, boost::bind (&ImageFrameTimeAxisView::remove_imageframe_group, this, iftag, (void*)this), gui_context());
 
 		ImageFrameGroupAdded(iftag, src) ; /* EMIT_SIGNAL */
 	}

gtk2_ardour/imageframe_view.cc

@@ -111,7 +111,7 @@ ImageFrameView::ImageFrameView(const string & item_id,
  */
 ImageFrameView::~ImageFrameView()
 {
-	GoingAway (this);
+	CatchDeletion (this);
 
 	// destroy any marker items we have associated with this item
 
@@ -287,7 +287,7 @@ ImageFrameView::add_marker_view_item(MarkerView* item, void* src)
 {
 	marker_view_list.push_back(item) ;
 
-	item->GoingAway.connect (*this, boost::bind (&ImageFrameView::remove_marker_view_item, this, (void*)this), gui_context());
+	item->CatchDeletion.connect (*this, boost::bind (&ImageFrameView::remove_marker_view_item, this, (void*)this), gui_context());
 
 	 MarkerViewAdded(item, src) ; /* EMIT_SIGNAL */
 }

gtk2_ardour/imageframe_view.h

@@ -78,7 +78,7 @@ class ImageFrameView : public TimeAxisViewItem
 		 */
 		~ImageFrameView() ;
 
-		static sigc::signal<void,ImageFrameView*> GoingAway;
+		static PBD::Signal1<void,ImageFrameView*> CatchDeletion;
 
 		//---------------------------------------------------------------------------------------//
 		// Position and duration Accessors/Mutators

gtk2_ardour/io_selector.cc

@@ -272,7 +272,7 @@ PortInsertWindow::PortInsertWindow (ARDOUR::Session* sess, boost::shared_ptr<ARD
 
 	signal_delete_event().connect (sigc::mem_fun (*this, &PortInsertWindow::wm_delete), false);
 
-	pi->GoingAway.connect (going_away_connection, boost::bind (&PortInsertWindow::plugin_going_away, this), gui_context());
+	pi->DropReferences.connect (going_away_connection, boost::bind (&PortInsertWindow::plugin_going_away, this), gui_context());
 }
 
 bool

gtk2_ardour/marker.cc

@@ -40,6 +40,8 @@
 using namespace std;
 using namespace ARDOUR;
 
+PBD::Signal1<void,Marker*> Marker::CatchDeletion;
+
 Marker::Marker (PublicEditor& ed, ArdourCanvas::Group& parent, guint32 rgba, const string& annotation,
 		Type type, nframes_t frame, bool handle_events)
 
@@ -285,7 +287,7 @@ Marker::Marker (PublicEditor& ed, ArdourCanvas::Group& parent, guint32 rgba, con
 
 Marker::~Marker ()
 {
-	drop_references ();
+	CatchDeletion (this); /* EMIT SIGNAL */
 
 	/* destroying the parent group destroys its contents, namely any polygons etc. that we added */
 	delete name_pixbuf;

gtk2_ardour/marker.h

@@ -24,9 +24,10 @@
 #include <glib.h>
 
 #include <libgnomecanvasmm/pixbuf.h>
+#include <sigc++/signal.h>
 
 #include "ardour/ardour.h"
-#include "pbd/destructible.h"
+#include "pbd/signals.h"
 
 #include "canvas.h"
 
@@ -37,7 +38,7 @@ namespace ARDOUR {
 
 class PublicEditor;
 
-class Marker : public PBD::Destructible
+class Marker : public sigc::trackable
 {
   public:
 	enum Type {
@@ -58,6 +59,8 @@ class Marker : public PBD::Destructible
 
 	virtual ~Marker ();
 
+	static PBD::Signal1<void,Marker*> CatchDeletion;
+
 	ArdourCanvas::Item& the_item() const;
 
 	void add_line (ArdourCanvas::Group*, double y_origin, double initial_height);

gtk2_ardour/marker_time_axis.cc

@@ -90,7 +90,7 @@ MarkerTimeAxis::MarkerTimeAxis (PublicEditor& ed, ARDOUR::Session* sess, Canvas&
  */
 MarkerTimeAxis::~MarkerTimeAxis()
 {
-	GoingAway ; /* EMIT_SIGNAL */
+	CatchDeletion (this); /* EMIT_SIGNAL */
 
 	// destroy the view helper
 	// this handles removing and destroying individual marker items

gtk2_ardour/marker_time_axis_view.cc

@@ -211,7 +211,7 @@ MarkerTimeAxisView::add_marker_view(ImageFrameView* ifv, std::string mark_type,
 	ifv->add_marker_view_item(mv, src) ;
 	marker_view_list.push_front(mv) ;
 
-	mv->GoingAway.connect (*this, boost::bind (&MarkerTimeAxisView::remove_marker_view, this, (void*)this), gui_context());
+	mv->CatchDeletion.connect (*this, boost::bind (&MarkerTimeAxisView::remove_marker_view, this, _1), gui_context());
 	
 	MarkerViewAdded(mv,src) ; /* EMIT_SIGNAL */
 
@@ -311,7 +311,7 @@ MarkerTimeAxisView::remove_named_marker_view(std::string item_id, void* src)
  * @param src the identity of the object that initiated the change
  */
 void
-MarkerTimeAxisView::remove_marker_view(MarkerView* mv, void* src)
+MarkerTimeAxisView::remove_marker_view(MarkerView* mv)
 {
 	ENSURE_GUI_THREAD (*this, &MarkerTimeAxisView::remove_marker_view, mv, src)
 

gtk2_ardour/marker_view.cc

@@ -27,7 +27,7 @@
 
 using namespace ARDOUR ;
 
-sigc::signal<void,MarkerView*> MarkerView::GoingAway;
+PBD::Signal1<void,MarkerView*> MarkerView::CatchDeletion
 
 //---------------------------------------------------------------------------------------//
 // Constructor / Desctructor

gtk2_ardour/marker_view.h

@@ -73,7 +73,7 @@ class MarkerView : public TimeAxisViewItem
 		 */
 		~MarkerView() ;
 
-		static sigc::signal<void,MarkerView*> GoingAway;
+		static PBD::Signal1<void,MarkerView*> CatchDeletion;
 
 		//---------------------------------------------------------------------------------------//
 		// Marker Type Methods

gtk2_ardour/midi_region_view.cc

@@ -1071,7 +1071,7 @@ MidiRegionView::add_ghost (TimeAxisView& tv)
 		}
 	}
 
-	ghost->GoingAway.connect (*this, ui_bind (&RegionView::remove_ghost, this, _1), gui_context());
+	ghost->CatchDeletion.connect (*this, ui_bind (&RegionView::remove_ghost, this, _1), gui_context());
 
 	return ghost;
 }

gtk2_ardour/midi_streamview.cc

@@ -180,7 +180,7 @@ MidiStreamView::add_region_view_internal (boost::shared_ptr<Region> r, bool wfd,
 	display_region (region_view, wfd);
 
 	/* catch regionview going away */
-	region->GoingAway.connect (*this, boost::bind (&MidiStreamView::remove_region_view, this, region), gui_context());
+	region->DropReferences.connect (*this, boost::bind (&MidiStreamView::remove_region_view, this, region), gui_context());
 
 	RegionViewAdded (region_view);
 

gtk2_ardour/mixer_strip.cc

@@ -312,7 +312,7 @@ MixerStrip::init ()
 
 MixerStrip::~MixerStrip ()
 {
-	drop_references ();
+	CatchDeletion (this);
 
 	delete input_selector;
 	delete output_selector;
@@ -1693,7 +1693,7 @@ MixerStrip::show_send (boost::shared_ptr<Send> send)
 	_current_delivery = send;
 
 	send->set_metering (true);
-	_current_delivery->GoingAway.connect (send_gone_connection, boost::bind (&MixerStrip::revert_to_default_display, this), gui_context());
+	_current_delivery->DropReferences.connect (send_gone_connection, boost::bind (&MixerStrip::revert_to_default_display, this), gui_context());
 
 	gain_meter().set_controls (_route, send->meter(), send->amp());
 	gain_meter().setup_meters ();

gtk2_ardour/mixer_ui.cc

@@ -334,8 +334,8 @@ Mixer_UI::add_strip (RouteList& routes)
 		}
 
 		route->NameChanged.connect (*this, boost::bind (&Mixer_UI::strip_name_changed, this, strip), gui_context());
+		route->DropReferences.connect (*this, boost::bind (&Mixer_UI::remove_strip, this, strip), gui_context());
 
-		strip->GoingAway.connect (*this, boost::bind (&Mixer_UI::remove_strip, this, strip), gui_context());
 		strip->WidthChanged.connect (sigc::mem_fun(*this, &Mixer_UI::strip_width_changed));
 		strip->signal_button_release_event().connect (sigc::bind (sigc::mem_fun(*this, &Mixer_UI::strip_button_release_event), strip));
 	}
@@ -497,6 +497,11 @@ Mixer_UI::session_going_away ()
 
 	group_model->clear ();
 	_selection.clear ();
+	track_model->clear ();
+
+	for (list<MixerStrip *>::iterator i = strips.begin(); i != strips.end(); ++i) {
+		delete (*i);
+	}
 
 	WindowTitle title(Glib::get_application_name());
 	title += _("Mixer");

gtk2_ardour/plugin_ui.cc

@@ -142,7 +142,7 @@ PluginUIWindow::PluginUIWindow (Gtk::Window* win, boost::shared_ptr<PluginInsert
 	add_events (Gdk::KEY_PRESS_MASK|Gdk::KEY_RELEASE_MASK|Gdk::BUTTON_PRESS_MASK|Gdk::BUTTON_RELEASE_MASK);
 
 	signal_delete_event().connect (sigc::bind (sigc::ptr_fun (just_hide_it), reinterpret_cast<Window*> (this)), false);
-	insert->GoingAway.connect (death_connection, boost::bind (&PluginUIWindow::plugin_going_away, this), gui_context());
+	insert->DropReferences.connect (death_connection, boost::bind (&PluginUIWindow::plugin_going_away, this), gui_context());
 
 	gint h = _pluginui->get_preferred_height ();
 	gint w = _pluginui->get_preferred_width ();
@@ -414,7 +414,7 @@ PlugUIBase::PlugUIBase (boost::shared_ptr<PluginInsert> pi)
 	plugin_analysis_expander.property_expanded().signal_changed().connect( sigc::mem_fun(*this, &PlugUIBase::toggle_plugin_analysis));
 	plugin_analysis_expander.set_expanded(false);
 	
-	insert->GoingAway.connect (death_connection, boost::bind (&PlugUIBase::plugin_going_away, this), gui_context());
+	insert->DropReferences.connect (death_connection, boost::bind (&PlugUIBase::plugin_going_away, this), gui_context());
 }
 
 PlugUIBase::~PlugUIBase()

gtk2_ardour/processor_box.cc

@@ -327,7 +327,7 @@ ProcessorBox::set_route (boost::shared_ptr<Route> r)
 	_route = r;
 
 	_route->processors_changed.connect (connections, ui_bind (&ProcessorBox::route_processors_changed, this, _1), gui_context());
-	_route->GoingAway.connect (connections, boost::bind (&ProcessorBox::route_going_away, this), gui_context());
+	_route->DropReferences.connect (connections, boost::bind (&ProcessorBox::route_going_away, this), gui_context());
 	_route->NameChanged.connect (connections, boost::bind (&ProcessorBox::route_name_changed, this), gui_context());
 
 	redisplay_processors ();

gtk2_ardour/region_view.cc

@@ -80,7 +80,6 @@ RegionView::RegionView (ArdourCanvas::Group*              parent,
 	, wait_for_data(false)
 	, _time_converter(r->session().tempo_map(), r->position())
 {
-	cerr << "RV " << this << " has ref on region " << _region->name() << endl;
 }
 
 RegionView::RegionView (const RegionView& other)
@@ -95,7 +94,6 @@ RegionView::RegionView (const RegionView& other)
 	valid = false;
 	_pixel_width = other._pixel_width;
 	_height = other._height;
-	cerr << "RV " << this << " has ref on region " << _region->name() << endl;
 }
 
 RegionView::RegionView (const RegionView& other, boost::shared_ptr<Region> other_region)
@@ -114,7 +112,6 @@ RegionView::RegionView (const RegionView& other, boost::shared_ptr<Region> other
 	valid = false;
 	_pixel_width = other._pixel_width;
 	_height = other._height;
-	cerr << "RV " << this << " has ref on region " << _region->name() << endl;
 }
 
 RegionView::RegionView (ArdourCanvas::Group*         parent,
@@ -137,7 +134,6 @@ RegionView::RegionView (ArdourCanvas::Group*         parent,
 	, wait_for_data(false)
 	, _time_converter(r->session().tempo_map(), r->position())
 {
-	cerr << "RV " << this << " has ref on region " << _region->name() << endl;
 }
 
 void

gtk2_ardour/return_ui.cc

@@ -110,7 +110,7 @@ ReturnUIWindow::ReturnUIWindow (boost::shared_ptr<Return> r, ARDOUR::Session* s)
 
 	set_name ("ReturnUIWindow");
 
-	r->GoingAway.connect (going_away_connection, boost::bind (&ReturnUIWindow::return_going_away, this), gui_context());
+	r->DropReferences.connect (going_away_connection, boost::bind (&ReturnUIWindow::return_going_away, this), gui_context());
 	signal_delete_event().connect (sigc::bind (sigc::ptr_fun (just_hide_it), reinterpret_cast<Window *> (this)));
 }
 

gtk2_ardour/route_params_ui.cc

@@ -182,7 +182,7 @@ RouteParams_UI::add_routes (RouteList& routes)
 		//route_select_list.rows().back().select ();
 
 		route->NameChanged.connect (*this, boost::bind (&RouteParams_UI::route_name_changed, this, boost::weak_ptr<Route>(route)), gui_context());
-		route->GoingAway.connect (*this, boost::bind (&RouteParams_UI::route_removed, this, boost::weak_ptr<Route>(route)), gui_context());
+		route->DropReferences.connect (*this, boost::bind (&RouteParams_UI::route_removed, this, boost::weak_ptr<Route>(route)), gui_context());
 	}
 }
 
@@ -522,7 +522,7 @@ RouteParams_UI::redirect_selected (boost::shared_ptr<ARDOUR::Processor> proc)
 		SendUI *send_ui = new SendUI (this, send, _session);
 
 		cleanup_view();
-		send->GoingAway.connect (_processor_going_away_connection, boost::bind (&RouteParams_UI::processor_going_away, this, boost::weak_ptr<Processor>(proc)), gui_context());
+		send->DropReferences.connect (_processor_going_away_connection, boost::bind (&RouteParams_UI::processor_going_away, this, boost::weak_ptr<Processor>(proc)), gui_context());
 		_active_view = send_ui;
 
 		redir_hpane.add2 (*_active_view);
@@ -533,7 +533,7 @@ RouteParams_UI::redirect_selected (boost::shared_ptr<ARDOUR::Processor> proc)
 		ReturnUI *return_ui = new ReturnUI (this, retrn, _session);
 
 		cleanup_view();
-		retrn->GoingAway.connect (_processor_going_away_connection, boost::bind (&RouteParams_UI::processor_going_away, this, boost::weak_ptr<Processor>(proc)), gui_context());
+		retrn->DropReferences.connect (_processor_going_away_connection, boost::bind (&RouteParams_UI::processor_going_away, this, boost::weak_ptr<Processor>(proc)), gui_context());
 		_active_view = return_ui;
 
 		redir_hpane.add2 (*_active_view);
@@ -544,7 +544,7 @@ RouteParams_UI::redirect_selected (boost::shared_ptr<ARDOUR::Processor> proc)
 		GenericPluginUI *plugin_ui = new GenericPluginUI (plugin_insert, true);
 
 		cleanup_view();
-		plugin_insert->plugin()->GoingAway.connect (_processor_going_away_connection, boost::bind (&RouteParams_UI::plugin_going_away, this, PreFader), gui_context());
+		plugin_insert->plugin()->DropReferences.connect (_processor_going_away_connection, boost::bind (&RouteParams_UI::plugin_going_away, this, PreFader), gui_context());
 		plugin_ui->start_updating (0);
 		_active_view = plugin_ui;
 
@@ -556,7 +556,7 @@ RouteParams_UI::redirect_selected (boost::shared_ptr<ARDOUR::Processor> proc)
 		PortInsertUI *portinsert_ui = new PortInsertUI (this, _session, port_insert);
 
 		cleanup_view();
-		port_insert->GoingAway.connect (_processor_going_away_connection, boost::bind (&RouteParams_UI::processor_going_away, this, boost::weak_ptr<Processor> (proc)), gui_context());
+		port_insert->DropReferences.connect (_processor_going_away_connection, boost::bind (&RouteParams_UI::processor_going_away, this, boost::weak_ptr<Processor> (proc)), gui_context());
 		_active_view = portinsert_ui;
 
 		redir_hpane.pack2 (*_active_view);

gtk2_ardour/route_processor_selection.cc

@@ -94,7 +94,7 @@ RouteRedirectSelection::add (boost::shared_ptr<Route> r)
 {
 	if (find (routes.begin(), routes.end(), r) == routes.end()) {
 		routes.push_back (r);
-		r->GoingAway.connect (*this, boost::bind (&RouteRedirectSelection::removed, this, boost::weak_ptr<Route>(r)), gui_context());
+		r->DropReferences.connect (*this, boost::bind (&RouteRedirectSelection::removed, this, boost::weak_ptr<Route>(r)), gui_context());
 		RoutesChanged();
 	}
 }

gtk2_ardour/route_time_axis.cc

@@ -269,8 +269,7 @@ RouteTimeAxisView::RouteTimeAxisView (PublicEditor& ed, Session* sess, boost::sh
 
 RouteTimeAxisView::~RouteTimeAxisView ()
 {
-	drop_references ();
+	CatchDeletion (this);
-	drop_connections ();
 
 	for (list<ProcessorAutomationInfo*>::iterator i = processor_automation.begin(); i != processor_automation.end(); ++i) {
 		delete *i;

gtk2_ardour/route_ui.cc

@@ -79,10 +79,6 @@ RouteUI::RouteUI (boost::shared_ptr<ARDOUR::Route> rt, ARDOUR::Session* sess)
 
 RouteUI::~RouteUI()
 {
-       /* derived classes should emit GoingAway so that they receive the signal
-          when the object is still a legal derived instance.
-       */
-
 	delete solo_menu;
 	delete mute_menu;
 	delete sends_menu;
@@ -171,7 +167,6 @@ RouteUI::self_delete ()
 
 	cerr << "\n\nExpect to see route " << _route->name() << " be deleted\n";
 	_route.reset (); /* drop reference to route, so that it can be cleaned up */
-
 	route_connections.drop_connections ();
 	delete_when_idle (this);
 }
@@ -188,7 +183,7 @@ RouteUI::set_route (boost::shared_ptr<Route> rp)
 	}
 
 	if (self_destruct) {
-		rp->GoingAway.connect (route_connections, boost::bind (&RouteUI::self_delete, this), gui_context());
+		rp->DropReferences.connect (route_connections, boost::bind (&RouteUI::self_delete, this), gui_context());
 	}
 	
 	mute_button->set_controllable (_route->mute_control());

gtk2_ardour/selection.cc

@@ -210,7 +210,7 @@ Selection::toggle (TimeAxisView* track)
 
 	if ((i = find (tracks.begin(), tracks.end(), track)) == tracks.end()) {
 		void (Selection::*pmf)(TimeAxisView*) = &Selection::remove;
-		track->GoingAway.connect (*this, boost::bind (pmf, this, track), gui_context());
+		track->CatchDeletion.connect (*this, boost::bind (pmf, this, track), gui_context());
 		tracks.push_back (track);
 	} else {
 		tracks.erase (i);
@@ -339,7 +339,7 @@ Selection::add (const TrackViewList& track_list)
 
 	for (list<TimeAxisView*>::const_iterator i = added.begin(); i != added.end(); ++i) {
 		void (Selection::*pmf)(TimeAxisView*) = &Selection::remove;
-		(*i)->GoingAway.connect (*this, boost::bind (pmf, this, (*i)), gui_context());
+		(*i)->CatchDeletion.connect (*this, boost::bind (pmf, this, (*i)), gui_context());
 	}
 
 	if (!added.empty()) {
@@ -950,7 +950,7 @@ Selection::add (Marker* m)
 
 		void (Selection::*pmf)(Marker*) = &Selection::remove;
 
-		m->GoingAway.connect (*this, boost::bind (pmf, this, m), gui_context());
+		m->CatchDeletion.connect (*this, boost::bind (pmf, this, _1), gui_context());
 
 		markers.push_back (m);
 		MarkersChanged();

gtk2_ardour/send_ui.cc

@@ -130,7 +130,7 @@ SendUIWindow::SendUIWindow (boost::shared_ptr<Send> s, Session* session)
 
 	set_name ("SendUIWindow");
 
-	s->GoingAway.connect (going_away_connection, boost::bind (&SendUIWindow::send_going_away, this), gui_context());
+	s->DropReferences.connect (going_away_connection, boost::bind (&SendUIWindow::send_going_away, this), gui_context());
 
 	signal_delete_event().connect (sigc::bind (
 					       sigc::ptr_fun (just_hide_it),

gtk2_ardour/time_axis_view.cc

@@ -925,7 +925,7 @@ TimeAxisView::add_ghost (RegionView* rv)
 
 	if(gr) {
 		ghosts.push_back(gr);
-		gr->GoingAway.connect (*this, ui_bind (&TimeAxisView::erase_ghost, this, _1), gui_context());
+		gr->CatchDeletion.connect (*this, ui_bind (&TimeAxisView::erase_ghost, this, _1), gui_context());
 	}
 }
 

gtk2_ardour/time_axis_view_item.h

@@ -296,7 +296,7 @@ class TimeAxisViewItem : public Selectable, public PBD::ScopedConnectionList
 
     /**
      * Emitted when this Group has been removed
-     * This is different to the GoingAway signal in that this signal
+     * This is different to the CatchDeletion signal in that this signal
      * is emitted during the deletion of this Time Axis, and not during
      * the destructor, this allows us to capture the source of the deletion
      * event

gtk2_ardour/visual_time_axis.h

@@ -117,7 +117,7 @@ class VisualTimeAxis : public TimeAxisView
 
 		/**
 		 * Emitted when this Visual Time Axis has been removed
-		 * This is different to the GoingAway signal in that this signal
+		 * This is different to the CatchDeletion signal in that this signal
 		 * is emitted during the deletion of this Time Axis, and not during
 		 * the destructor, this allows us to capture the source of the deletion
 		 * event

libs/ardour/ardour/session.h

@@ -570,11 +570,11 @@ class Session : public PBD::StatefulDestructible, public PBD::ScopedConnectionLi
 
 	/* named selections */
 
-	NamedSelection* named_selection_by_name (std::string name);
+	boost::shared_ptr<NamedSelection> named_selection_by_name (std::string name);
-	void add_named_selection (NamedSelection *);
+	void add_named_selection (boost::shared_ptr<NamedSelection>);
-	void remove_named_selection (NamedSelection *);
+	void remove_named_selection (boost::shared_ptr<NamedSelection>);
 
-	template<class T> void foreach_named_selection (T& obj, void (T::*func)(NamedSelection&));
+	template<class T> void foreach_named_selection (T& obj, void (T::*func)(boost::shared_ptr<NamedSelection>));
 	PBD::Signal0<void> NamedSelectionAdded;
 	PBD::Signal0<void> NamedSelectionRemoved;
 
@@ -1287,7 +1287,7 @@ class Session : public PBD::StatefulDestructible, public PBD::ScopedConnectionLi
 	/* NAMED SELECTIONS */
 
 	mutable Glib::Mutex named_selection_lock;
-	typedef std::set<NamedSelection *> NamedSelectionList;
+	typedef std::set<boost::shared_ptr<NamedSelection> > NamedSelectionList;
 	NamedSelectionList named_selections;
 
 	int load_named_selections (const XMLNode&);

libs/ardour/ardour/session_handle.h

@@ -34,6 +34,7 @@ class SessionHandleRef : public PBD::ScopedConnectionList
   protected:
 	ARDOUR::Session&          _session;
 	virtual void session_going_away ();
+	virtual void insanity_check ();
 };
 
 class SessionHandlePtr

libs/ardour/audio_diskstream.cc

@@ -1505,7 +1505,7 @@ AudioDiskstream::transport_stopped (struct tm& when, time_t twhen, bool abort_ca
 				continue; /* XXX is this OK? */
 			}
 
-			region->GoingAway.connect_same_thread (*this, boost::bind (&Diskstream::remove_region_from_last_capture, this, boost::weak_ptr<Region>(region)));
+			region->DropReferences.connect_same_thread (*this, boost::bind (&Diskstream::remove_region_from_last_capture, this, boost::weak_ptr<Region>(region)));
 
 			_last_capture_regions.push_back (region);
 

libs/ardour/audio_playlist.cc

@@ -102,10 +102,6 @@ AudioPlaylist::AudioPlaylist (boost::shared_ptr<const AudioPlaylist> other, nfra
 
 AudioPlaylist::~AudioPlaylist ()
 {
-	drop_references ();
-
-	/* drop connections to signals */
-
 	_crossfades.clear ();
 }
 

libs/ardour/automation_list.cc

@@ -112,7 +112,6 @@ AutomationList::AutomationList (const XMLNode& node, Evoral::Parameter id)
 
 AutomationList::~AutomationList()
 {
-	drop_references ();
 }
 
 boost::shared_ptr<Evoral::ControlList>

libs/ardour/coreaudiosource.cc

@@ -90,7 +90,6 @@ CoreAudioSource::init_cafile ()
 
 CoreAudioSource::~CoreAudioSource ()
 {
-	drop_references ();
 }
 
 int

libs/ardour/diskstream.cc

@@ -148,7 +148,7 @@ Diskstream::set_route (Route& r)
 	non_realtime_input_change ();
 	set_align_style_from_io ();
 
-	_route->GoingAway.connect_same_thread (*this, boost::bind (&Diskstream::route_going_away, this));
+	_route->Destroyed.connect_same_thread (*this, boost::bind (&Diskstream::route_going_away, this));
 }
 
 void
@@ -340,7 +340,7 @@ Diskstream::use_playlist (boost::shared_ptr<Playlist> playlist)
 		}
 
 		_playlist->Modified.connect_same_thread (playlist_connections, boost::bind (&Diskstream::playlist_modified, this));
-		_playlist->GoingAway.connect_same_thread (playlist_connections, boost::bind (&Diskstream::playlist_deleted, this, boost::weak_ptr<Playlist>(_playlist)));
+		_playlist->DropReferences.connect_same_thread (playlist_connections, boost::bind (&Diskstream::playlist_deleted, this, boost::weak_ptr<Playlist>(_playlist)));
 		_playlist->RangesMoved.connect_same_thread (playlist_connections, boost::bind (&Diskstream::playlist_ranges_moved, this, _1));
 	}
 

libs/ardour/internal_send.cc

@@ -43,7 +43,7 @@ InternalSend::InternalSend (Session& s, boost::shared_ptr<MuteMaster> mm, boost:
 
 	set_name (sendto->name());
 
-	_send_to->GoingAway.connect_same_thread (*this, boost::bind (&InternalSend::send_to_going_away, this));
+	_send_to->DropReferences.connect_same_thread (*this, boost::bind (&InternalSend::send_to_going_away, this));
 	_send_to->NameChanged.connect_same_thread (*this, boost::bind (&InternalSend::send_to_name_changed, this));
 }
 

libs/ardour/ladspa_plugin.cc

@@ -144,8 +144,6 @@ LadspaPlugin::~LadspaPlugin ()
 	deactivate ();
 	cleanup ();
 
-	drop_references ();
-
 	/* XXX who should close a plugin? */
 
         // dlclose (module);

libs/ardour/lv2_plugin.cc

@@ -181,8 +181,6 @@ LV2Plugin::~LV2Plugin ()
 	deactivate ();
 	cleanup ();
 
-	drop_references ();
-
 	slv2_instance_free(_instance);
 	slv2_value_free(_name);
 	slv2_value_free(_author);

libs/ardour/midi_diskstream.cc

@@ -1024,7 +1024,7 @@ MidiDiskstream::transport_stopped (struct tm& /*when*/, time_t /*twhen*/, bool a
 				continue; /* XXX is this OK? */
 			}
 
-			region->GoingAway.connect_same_thread (*this, boost::bind (&Diskstream::remove_region_from_last_capture, this, boost::weak_ptr<Region>(region)));
+			region->DropReferences.connect_same_thread (*this, boost::bind (&Diskstream::remove_region_from_last_capture, this, boost::weak_ptr<Region>(region)));
 
 			_last_capture_regions.push_back (region);
 

libs/ardour/midi_playlist.cc

@@ -71,9 +71,6 @@ MidiPlaylist::MidiPlaylist (boost::shared_ptr<const MidiPlaylist> other, nframes
 
 MidiPlaylist::~MidiPlaylist ()
 {
-	drop_references ();
-
-	/* drop connections to signals */
 }
 
 template<typename Time>

libs/ardour/midi_ui.cc

@@ -89,6 +89,8 @@ MidiControlUI::change_midi_ports ()
 bool
 MidiControlUI::midi_input_handler (IOCondition ioc, MIDI::Port* port)
 {
+	DEBUG_TRACE (DEBUG::MidiIO, string_compose ("something happend on  %1\n", port->name()));
+
 	if (ioc & ~IO_IN) {
 		return false;
 	}

libs/ardour/named_selection.cc

@@ -52,8 +52,6 @@ NamedSelection::NamedSelection (string n, PlaylistList& l)
 		(*i)->set_name (new_name);
 		(*i)->use();
 	}
-
-	NamedSelectionCreated (this);
 }
 
 NamedSelection::NamedSelection (Session& session, const XMLNode& node)
@@ -101,8 +99,9 @@ NamedSelection::NamedSelection (Session& session, const XMLNode& node)
 NamedSelection::~NamedSelection ()
 {
 	for (PlaylistList::iterator i = playlists.begin(); i != playlists.end(); ++i) {
-		(*i)->release ();
+		/* XXX who really owns these? us or the session? */
 		(*i)->drop_references ();
+		(*i)->release ();
 	}
 }
 

libs/ardour/plugin_insert.cc

@@ -130,7 +130,6 @@ PluginInsert::set_count (uint32_t num)
 
 PluginInsert::~PluginInsert ()
 {
-	drop_references ();
 }
 
 void

libs/ardour/port_insert.cc

@@ -61,7 +61,6 @@ PortInsert::PortInsert (Session& s, boost::shared_ptr<MuteMaster> mm, const XMLN
 
 PortInsert::~PortInsert ()
 {
-	drop_references ();
 }
 
 void

libs/ardour/region.cc

@@ -109,7 +109,7 @@ Region::Region (boost::shared_ptr<Source> src, nframes_t start, nframes_t length
 	_sources.push_back (src);
 	_master_sources.push_back (src);
 
-	src->GoingAway.connect_same_thread (*this, boost::bind (&Region::source_deleted, this, boost::weak_ptr<Source>(src)));
+	src->DropReferences.connect_same_thread (*this, boost::bind (&Region::source_deleted, this, boost::weak_ptr<Source>(src)));
 
 	assert(_sources.size() > 0);
 	_positional_lock_style = AudioTime;
@@ -338,7 +338,6 @@ Region::Region (boost::shared_ptr<Source> src, const XMLNode& node)
 Region::~Region ()
 {
 	DEBUG_TRACE (DEBUG::Destruction, string_compose ("Region %1 destructor @ %2\n", _name, this));
-	drop_references ();
 }
 
 void
@@ -1416,7 +1415,12 @@ void
 Region::source_deleted (boost::weak_ptr<Source>)
 {
 	_sources.clear ();
-	cerr << "Send drop ref signal from region " << ' ' << this << endl;
+
+	/* this is a very special case: at least one of the region's
+	   sources has bee deleted, so invalidate all references to
+	   ourselves.
+	*/
+
 	drop_references ();
 }
 
@@ -1586,14 +1590,14 @@ Region::use_sources (SourceList const & s)
 
 	for (SourceList::const_iterator i = s.begin (); i != s.end(); ++i) {
 		_sources.push_back (*i);
-		(*i)->GoingAway.connect_same_thread (*this, boost::bind (&Region::source_deleted, this, boost::weak_ptr<Source>(*i)));
+		(*i)->DropReferences.connect_same_thread (*this, boost::bind (&Region::source_deleted, this, boost::weak_ptr<Source>(*i)));
 		unique_srcs.insert (*i);
 	}
 
 	for (SourceList::const_iterator i = s.begin (); i != s.end(); ++i) {
 		_master_sources.push_back (*i);
 		if (unique_srcs.find (*i) == unique_srcs.end()) {
-			(*i)->GoingAway.connect_same_thread (*this, boost::bind (&Region::source_deleted, this, boost::weak_ptr<Source>(*i)));
+			(*i)->DropReferences.connect_same_thread (*this, boost::bind (&Region::source_deleted, this, boost::weak_ptr<Source>(*i)));
 		}
 	}
 }

libs/ardour/return.cc

@@ -67,7 +67,6 @@ Return::Return (Session& s, const XMLNode& node, bool internal)
 
 Return::~Return ()
 {
-	drop_references ();
 }
 
 XMLNode&

libs/ardour/route.cc

@@ -792,6 +792,7 @@ Route::add_processor (boost::shared_ptr<Processor> processor, ProcessorList::ite
 			// XXX: do we want to emit the signal here ? change call order.
 			processor->activate ();
 		}
+
 		processor->ActiveChanged.connect_same_thread (*this, boost::bind (&Session::update_latency_compensation, &_session, false, false));
 
 		_output->set_user_latency (0);

libs/ardour/route_group.cc

@@ -76,7 +76,7 @@ RouteGroup::add (boost::shared_ptr<Route> r)
 	routes->push_back (r);
 
 	r->join_route_group (this);
-	r->GoingAway.connect_same_thread (*this, boost::bind (&RouteGroup::remove_when_going_away, this, boost::weak_ptr<Route> (r)));
+	r->DropReferences.connect_same_thread (*this, boost::bind (&RouteGroup::remove_when_going_away, this, boost::weak_ptr<Route> (r)));
 	
 	_session.set_dirty ();
 	changed (); /* EMIT SIGNAL */

libs/ardour/send.cc

@@ -64,7 +64,6 @@ Send::Send (Session& s, boost::shared_ptr<MuteMaster> mm, const XMLNode& node, i
 
 Send::~Send ()
 {
-	drop_references ();
 }
 
 void

libs/ardour/session.cc

@@ -388,32 +388,19 @@ Session::destroy ()
 	
 	AudioDiskstream::free_working_buffers();
 
+	/* tell everyone who is still standing that we're about to die */
+	drop_references ();
+
+	/* tell everyone to drop references and delete objects as we go */
+
 	DEBUG_TRACE (DEBUG::Destruction, "delete named selections\n");
-	for (NamedSelectionList::iterator i = named_selections.begin(); i != named_selections.end(); ) {
+	named_selections.clear ();
-		NamedSelectionList::iterator tmp;
-
-		tmp = i;
-		++tmp;
-
-		delete *i;
-		i = tmp;
-	}
 
 	DEBUG_TRACE (DEBUG::Destruction, "delete regions\n");
-	for (RegionList::iterator i = regions.begin(); i != regions.end(); ) {
+	for (RegionList::iterator i = regions.begin(); i != regions.end(); ++i) {
-		RegionList::iterator tmp;
+		DEBUG_TRACE(DEBUG::Destruction, string_compose ("Dropping for region %1 ; pre-ref = %2\n", i->second->name(), i->second.use_count()));
-
-		tmp = i;
-		++tmp;
-
-		boost::shared_ptr<Region> keep (i->second);
-		
-		DEBUG_TRACE(DEBUG::Destruction, string_compose ("Dropping for region %1 (%2); pre-ref = %3\n", i->second->name(), i->second.get(), i->second.use_count()));
 		i->second->drop_references ();
-		DEBUG_TRACE(DEBUG::Destruction, string_compose ("region post ref = %1\n", i->second.use_count()));
-		i = tmp;
 	}
-
 	regions.clear ();
 
 	DEBUG_TRACE (DEBUG::Destruction, "delete routes\n");
@@ -427,10 +414,12 @@ Session::destroy ()
 	{
 		RCUWriter<RouteList> writer (routes);
 		boost::shared_ptr<RouteList> r = writer.get_copy ();
+
 		for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
 			DEBUG_TRACE(DEBUG::Destruction, string_compose ("Dropping for route %1 ; pre-ref = %2\n", (*i)->name(), (*i).use_count()));
 			(*i)->drop_references ();
 		}
+
 		r->clear ();
 		/* writer goes out of scope and updates master */
 	}
@@ -444,28 +433,22 @@ Session::destroy ()
 			DEBUG_TRACE(DEBUG::Destruction, string_compose ("Dropping for diskstream %1 ; pre-ref = %2\n", (*i)->name(), (*i).use_count()));
 			(*i)->drop_references ();
 		}
+
 		dsl->clear ();
 	}
 	diskstreams.flush ();
 
 	DEBUG_TRACE (DEBUG::Destruction, "delete sources\n");
-	for (SourceMap::iterator i = sources.begin(); i != sources.end(); ) {
+	for (SourceMap::iterator i = sources.begin(); i != sources.end(); ++i) {
-		SourceMap::iterator tmp;
-
-		tmp = i;
-		++tmp;
-
 		DEBUG_TRACE(DEBUG::Destruction, string_compose ("Dropping for source %1 ; pre-ref = %2\n", i->second->path(), i->second.use_count()));
 		i->second->drop_references ();
-
-		i = tmp;
 	}
 
 	sources.clear ();
 
-
 	DEBUG_TRACE (DEBUG::Destruction, "delete route groups\n");
 	for (list<RouteGroup *>::iterator i = _route_groups.begin(); i != _route_groups.end(); ++i) {
+		
 		delete *i;
 	}
 
@@ -476,10 +459,6 @@ Session::destroy ()
 	/* not strictly necessary, but doing it here allows the shared_ptr debugging to work */
 	playlists.reset ();
 
-	/* tell everyone who is still standing that we're about to die */
-
-	drop_references ();
-
 	boost_debug_list_ptrs ();
 
 	DEBUG_TRACE (DEBUG::Destruction, "Session::destroy() done\n");
@@ -2813,8 +2792,6 @@ Session::add_regions (vector<boost::shared_ptr<Region> >& new_regions)
 			}
 
 			region->StateChanged.connect_same_thread (*this, boost::bind (&Session::region_changed, this, _1, boost::weak_ptr<Region>(region)));
-			region->GoingAway.connect_same_thread (*this, boost::bind (&Session::remove_region, this, boost::weak_ptr<Region>(region)));
-
 			update_region_name_map (region);
 		}
 
@@ -3001,7 +2978,6 @@ Session::add_source (boost::shared_ptr<Source> source)
 	}
 
 	if (result.second) {
-		source->GoingAway.connect_same_thread (*this, boost::bind (&Session::remove_source, this, boost::weak_ptr<Source> (source)));
 		set_dirty();
 	}
 
@@ -3390,10 +3366,7 @@ Session::add_playlist (boost::shared_ptr<Playlist> playlist, bool unused)
 		return;
 	}
 
-	bool existing = playlists->add (playlist);
+	playlists->add (playlist);
-	if (!existing) {
-		playlist->GoingAway.connect_same_thread (*this, boost::bind (&Session::remove_playlist, this, boost::weak_ptr<Playlist>(playlist)));
-	}
 
 	if (unused) {
 		playlist->release();
@@ -3566,7 +3539,11 @@ Session::graph_reordered ()
 void
 Session::add_processor (Processor* processor)
 {
-	processor->GoingAway.connect_same_thread (*this, boost::bind (&Session::remove_processor, this, processor));
+	/* Session does not own Processors (they belong to a Route) but we do want to track
+	   the arrival and departure of port inserts, sends and returns for naming
+	   purposes.
+	*/
+	processor->DropReferences.connect_same_thread (*this, boost::bind (&Session::remove_processor, this, processor));
 	set_dirty();
 }
 
@@ -3810,37 +3787,33 @@ Session::mark_insert_id (uint32_t id)
 
 /* Named Selection management */
 
-NamedSelection *
+boost::shared_ptr<NamedSelection>
 Session::named_selection_by_name (string name)
 {
 	Glib::Mutex::Lock lm (named_selection_lock);
 	for (NamedSelectionList::iterator i = named_selections.begin(); i != named_selections.end(); ++i) {
 		if ((*i)->name == name) {
-			return* i;
+			return *i;
 		}
 	}
-	return 0;
+	return boost::shared_ptr<NamedSelection>();
 }
 
 void
-Session::add_named_selection (NamedSelection* named_selection)
+Session::add_named_selection (boost::shared_ptr<NamedSelection> named_selection)
 {
 	{
 		Glib::Mutex::Lock lm (named_selection_lock);
 		named_selections.insert (named_selections.begin(), named_selection);
 	}
 
-	for (list<boost::shared_ptr<Playlist> >::iterator i = named_selection->playlists.begin(); i != named_selection->playlists.end(); ++i) {
-		add_playlist (*i);
-	}
-
 	set_dirty();
 
 	NamedSelectionAdded (); /* EMIT SIGNAL */
 }
 
 void
-Session::remove_named_selection (NamedSelection* named_selection)
+Session::remove_named_selection (boost::shared_ptr<NamedSelection> named_selection)
 {
 	bool removed = false;
 
@@ -3850,7 +3823,6 @@ Session::remove_named_selection (NamedSelection* named_selection)
 		NamedSelectionList::iterator i = find (named_selections.begin(), named_selections.end(), named_selection);
 
 		if (i != named_selections.end()) {
-			delete (*i);
 			named_selections.erase (i);
 			set_dirty();
 			removed = true;
@@ -4186,6 +4158,10 @@ Session::compute_initial_length ()
 void
 Session::sync_order_keys (std::string const & base)
 {
+	if (deletion_in_progress()) {
+		return;
+	}
+
 	if (!Config->get_sync_all_route_ordering()) {
 		/* leave order keys as they are */
 		return;

libs/ardour/session_handle.cc

@@ -32,7 +32,7 @@ SessionHandlePtr::SessionHandlePtr (Session* s)
 	: _session (s) 
 {
 	if (_session) {
-		_session->GoingAway.connect_same_thread (_session_connections, boost::bind (&SessionHandlePtr::session_going_away, this));
+		_session->DropReferences.connect_same_thread (_session_connections, boost::bind (&SessionHandlePtr::session_going_away, this));
 	}
 }	
 
@@ -47,7 +47,7 @@ SessionHandlePtr::set_session (Session* s)
 
 	if (s) {
 		_session = s;
-		_session->GoingAway.connect_same_thread (_session_connections, boost::bind (&SessionHandlePtr::session_going_away, this));
+		_session->DropReferences.connect_same_thread (_session_connections, boost::bind (&SessionHandlePtr::session_going_away, this));
 	}
 }
 
@@ -63,11 +63,19 @@ SessionHandlePtr::session_going_away ()
 SessionHandleRef::SessionHandleRef (Session& s)
 	: _session (s) 
 {
-	_session.GoingAway.connect_same_thread (*this, boost::bind (&SessionHandleRef::session_going_away, this));
+	_session.DropReferences.connect_same_thread (*this, boost::bind (&SessionHandleRef::session_going_away, this));
+	_session.Destroyed.connect_same_thread (*this, boost::bind (&SessionHandleRef::insanity_check, this));
 }	
 
 void
 SessionHandleRef::session_going_away ()
 {
-	error << string_compose (_("programming error: %1"), "SessionHandleRef exists across sesssion deletion!") << endmsg;
+	/* a handleRef is allowed to exist at the time of DropReferences, but not at the time of Destroyed
+	 */
+}
+
+void
+SessionHandleRef::insanity_check ()
+{
+	cerr << string_compose (_("programming error: %1"), "SessionHandleRef exists across sesssion deletion!") << endl;
 }

libs/ardour/session_playlists.cc

@@ -43,6 +43,7 @@ SessionPlaylists::~SessionPlaylists ()
 		++tmp;
 
 		DEBUG_TRACE(DEBUG::Destruction, string_compose ("Dropping for used playlist %1 ; pre-ref = %2\n", (*i)->name(), (*i).use_count()));
+		boost::shared_ptr<Playlist> keeper (*i);
 		(*i)->drop_references ();
 
 		i = tmp;
@@ -56,6 +57,7 @@ SessionPlaylists::~SessionPlaylists ()
 		++tmp;
 
 		DEBUG_TRACE(DEBUG::Destruction, string_compose ("Dropping for unused playlist %1 ; pre-ref = %2\n", (*i)->name(), (*i).use_count()));
+		boost::shared_ptr<Playlist> keeper (*i);
 		(*i)->drop_references ();
 
 		i = tmp;
@@ -291,6 +293,7 @@ SessionPlaylists::maybe_delete_unused (boost::function<int(boost::shared_ptr<Pla
 	/* now delete any that were marked for deletion */
 
 	for (vector<boost::shared_ptr<Playlist> >::iterator x = playlists_tbd.begin(); x != playlists_tbd.end(); ++x) {
+		boost::shared_ptr<Playlist> keeper (*x);
 		(*x)->drop_references ();
 	}
 

libs/ardour/session_state.cc

@@ -274,7 +274,6 @@ Session::first_stage_init (string fullpath, string snapshot_name)
 	SourceFactory::SourceCreated.connect_same_thread (*this, boost::bind (&Session::add_source, this, _1));
 	PlaylistFactory::PlaylistCreated.connect_same_thread (*this, boost::bind (&Session::add_playlist, this, _1, _2));
 	Processor::ProcessorCreated.connect_same_thread (*this, boost::bind (&Session::add_processor, this, _1));
-	NamedSelection::NamedSelectionCreated.connect_same_thread (*this, boost::bind (&Session::add_named_selection, this, _1));
 	AutomationList::AutomationListCreated.connect_same_thread (*this, boost::bind (&Session::add_automation_list, this, _1));
 	Controllable::Destroyed.connect_same_thread (*this, boost::bind (&Session::remove_controllable, this, _1));
 	IO::PortCountChanged.connect_same_thread (*this, boost::bind (&Session::ensure_buffers, this, _1));
@@ -789,7 +788,7 @@ Session::load_state (string snapshot_name)
 
 		/* there is pending state from a crashed capture attempt */
 
-		if (AskAboutPendingState()) {
+		if (*AskAboutPendingState()) {
 			state_was_pending = true;
 		}
 	}
@@ -1126,7 +1125,7 @@ Session::set_state (const XMLNode& node, int version)
 		_nominal_frame_rate = atoi (prop->value());
 
 		if (_nominal_frame_rate != _current_frame_rate) {
-			if (AskAboutSampleRateMismatch (_nominal_frame_rate, _current_frame_rate)) {
+			if (*AskAboutSampleRateMismatch (_nominal_frame_rate, _current_frame_rate)) {
 				return -1;
 			}
 		}

libs/ardour/sndfilesource.cc

@@ -246,8 +246,6 @@ SndFileSource::open ()
 
 SndFileSource::~SndFileSource ()
 {
-	drop_references ();
-
 	if (sf) {
 		sf_close (sf);
 		sf = 0;

libs/ardour/vst_plugin.cc

@@ -102,7 +102,6 @@ VSTPlugin::VSTPlugin (const VSTPlugin &other)
 VSTPlugin::~VSTPlugin ()
 {
 	deactivate ();
-	drop_references ();
 	fst_close (_fst);
 }
 

libs/gtkmm2ext/gtk_ui.cc

@@ -359,7 +359,11 @@ UI::do_request (UIRequest* req)
 		do_quit ();
 
 	} else if (req->type == CallSlot) {
-
+#ifndef NDEBUG
+		if (getenv ("DEBUG_THREADED_SIGNALS")) {
+			cerr << "call slot for " << name() << endl;
+		}
+#endif
 		req->the_slot ();
 
 	} else if (req->type == TouchDisplay) {

libs/midi++2/parser.cc

@@ -313,7 +313,6 @@ Parser::trace (bool onoff, ostream *o, const string &prefix)
 	trace_connection.disconnect ();
 
 	if (onoff) {
-		cerr << "enabling tracing for port " << _port.name() << endl;
 		trace_stream = o;
 		trace_prefix = prefix;
 		any.connect_same_thread (trace_connection, boost::bind (&Parser::trace_event, this, _1, _2, _3));
@@ -404,6 +403,7 @@ Parser::scanner (unsigned char inbyte)
 	 */
 
 	if (state == VARIABLELENGTH && statusbit)  {
+
 		/* The message has ended, so process it */
 
 		/* add EOX to any sysex message */
@@ -419,7 +419,7 @@ Parser::scanner (unsigned char inbyte)
 		}
 		cerr << dec << endl;
 #endif
-		if (msgindex > 0 && edit (msgbuf, msgindex) >= 0) {
+		if (msgindex > 0 && (edit.empty() || !(*edit (msgbuf, msgindex) >= 0))) {
 			if (!possible_mmc (msgbuf, msgindex) || _mmc_forward) {
 				if (!possible_mtc (msgbuf, msgindex) || _mtc_forward) {
 					if (!_offline) {
@@ -490,8 +490,7 @@ Parser::scanner (unsigned char inbyte)
 		
 	case NEEDONEBYTE:
 		/* We've completed a 1 or 2 byte message. */
-		
+		if (edit.empty() || !(*edit (msgbuf, msgindex) == 0)) {
-		if (edit (msgbuf, msgindex) == 0) {
 			
 			/* message not cancelled by an editor */
 			

libs/pbd/controllable.cc

@@ -62,23 +62,23 @@ Controllable::add (Controllable& ctl)
 
 	/* Controllable::remove() is static - no need to manage this connection */
 
-	ctl.GoingAway.connect_same_thread (registry_connections, boost::bind (&Controllable::remove, ref (ctl)));
+	ctl.DropReferences.connect_same_thread (registry_connections, boost::bind (&Controllable::remove, &ctl));
 }
 
 void
-Controllable::remove (Controllable& ctl)
+Controllable::remove (Controllable* ctl)
 {
 	Glib::RWLock::WriterLock lm (registry_lock);
 
 	for (Controllables::iterator i = registry.begin(); i != registry.end(); ++i) {
-		if ((*i) == &ctl) {
+		if ((*i) == ctl) {
 			registry.erase (i);
 			break;
 		}
 	}
 
-	if (!ctl.uri().empty()) {
+	if (!ctl->uri().empty()) {
-		ControllablesByURI::iterator i = registry_by_uri.find (ctl.uri());
+		ControllablesByURI::iterator i = registry_by_uri.find (ctl->uri());
 		if (i != registry_by_uri.end()) {
 			registry_by_uri.erase (i);
 		}

libs/pbd/pbd/abstract_ui.cc

@@ -1,4 +1,5 @@
 #include <unistd.h>
+#include <iostream>
 
 #include "pbd/stacktrace.h"
 #include "pbd/abstract_ui.h"
@@ -9,11 +10,22 @@
 
 using namespace std;
 
+static void do_not_delete_the_request_buffer (void*) { }
+
+template<typename R>
+Glib::StaticPrivate<typename AbstractUI<R>::RequestBuffer> AbstractUI<R>::per_thread_request_buffer;
+
 template <typename RequestObject>
 AbstractUI<RequestObject>::AbstractUI (const string& name)
 	: BaseUI (name)
 {
-	PBD::ThreadCreatedWithRequestSize.connect (mem_fun (*this, &AbstractUI<RequestObject>::register_thread));
+	void (AbstractUI<RequestObject>::*pmf)(string,pthread_t,string,uint32_t) = &AbstractUI<RequestObject>::register_thread;
+
+	/* better to make this connect a handler that runs in the UI event loop but the syntax seems hard, and 
+	   register_thread() is thread safe anyway.
+	*/
+
+	PBD::ThreadCreatedWithRequestSize.connect_same_thread (new_thread_connection, boost::bind (pmf, this, _1, _2, _3, _4));
 }
 
 template <typename RequestObject> void
@@ -30,7 +42,7 @@ AbstractUI<RequestObject>::register_thread (string target_gui, pthread_t thread_
 		request_buffers[thread_id] = b;
 	}
 
-	per_thread_request_buffer.set (b);
+	per_thread_request_buffer.set (b, do_not_delete_the_request_buffer);
 }
 
 template <typename RequestObject> RequestObject*
@@ -143,6 +155,11 @@ template<typename RequestObject> void
 AbstractUI<RequestObject>::call_slot (const boost::function<void()>& f)
 {
 	if (caller_is_self()) {
+#ifndef NDEBUG
+		if (getenv ("DEBUG_THREADED_SIGNALS")) {
+			std::cerr << "functor called in correct thread for " << name() << " , execute ...\n";
+		}
+#endif
 		f ();
 		return;
 	}
@@ -154,6 +171,11 @@ AbstractUI<RequestObject>::call_slot (const boost::function<void()>& f)
 	}
 
 	req->the_slot = f;
+#ifndef NDEBUG
+	if (getenv ("DEBUG_THREADED_SIGNALS")) {
+		std::cerr << "functor called in wrong thread for " << name() << " (from " << pthread_name() << ") send request ...\n";
+	}
+#endif
 	send_request (req);
 }	
 

libs/pbd/pbd/abstract_ui.h

@@ -24,12 +24,11 @@
 #include <string>
 #include <pthread.h>
 
-#include <sigc++/sigc++.h>
-
 #include <glibmm/thread.h>
 
 #include "pbd/receiver.h"
 #include "pbd/ringbufferNPT.h"
+#include "pbd/signals.h"
 #include "pbd/base_ui.h"
 
 class Touchable;
@@ -52,7 +51,7 @@ class AbstractUI : public BaseUI
 
 	Glib::Mutex request_buffer_map_lock;
 	RequestBufferMap request_buffers;
-	Glib::Private<RequestBuffer> per_thread_request_buffer;
+	static Glib::StaticPrivate<RequestBuffer> per_thread_request_buffer;
 	
 	Glib::Mutex               request_list_lock;
 	std::list<RequestObject*> request_list;
@@ -62,6 +61,7 @@ class AbstractUI : public BaseUI
 	void send_request (RequestObject *);
 
 	virtual void do_request (RequestObject *) = 0;
+	PBD::ScopedConnection new_thread_connection;
 };
 
 #endif /* __pbd_abstract_ui_h__ */

libs/pbd/pbd/controllable.h

@@ -73,7 +73,7 @@ class Controllable : public PBD::StatefulDestructible {
 	bool        _touching;
 
 	static void add (Controllable&);
-	static void remove (Controllable&);
+	static void remove (Controllable*);
 
 	typedef std::set<PBD::Controllable*> Controllables;
 	typedef std::map<std::string,PBD::Controllable*> ControllablesByURI;

libs/pbd/pbd/destructible.h

@@ -26,14 +26,13 @@ namespace PBD {
 
 class Destructible {
   public:
-        Destructible() : refs_dropped (false){}
+        Destructible() {}
-	virtual ~Destructible () {}
+	virtual ~Destructible () { Destroyed(); }
 	
-	PBD::Signal0<void> GoingAway;
+	PBD::Signal0<void> Destroyed;
-	void drop_references () { if (!refs_dropped) { GoingAway(); } refs_dropped = true; }
+	PBD::Signal0<void> DropReferences;
 
-  private:
+	void drop_references () { DropReferences();  }
-	bool refs_dropped;
 };
 
 }

libs/pbd/pbd/memento_command.h

@@ -42,7 +42,7 @@ public:
 		: obj(a_object), before(a_before), after(a_after)
 	{
 		/* if the object dies, make sure that we die and that everyone knows about it */
-		obj.GoingAway.connect_same_thread (obj_death_connection, boost::bind (&MementoCommand::object_died, this));
+		obj.Destroyed.connect_same_thread (obj_death_connection, boost::bind (&MementoCommand::object_died, this));
 	}
 
 	~MementoCommand () {

libs/pbd/pbd/pthread_utils.h

@@ -25,7 +25,7 @@
 #include <string>
 #include <stdint.h>
 
-#include <sigc++/sigc++.h>
+#include <pbd/signals.h>
 
 int  pthread_create_and_store (std::string name, pthread_t  *thread, void * (*start_routine)(void *), void * arg);
 void pthread_cancel_one (pthread_t thread);
@@ -36,10 +36,7 @@ std::string pthread_name ();
 
 namespace PBD {
 	extern void notify_gui_about_thread_creation (std::string, pthread_t, std::string, int requests = 256);
-	extern void notify_gui_about_thread_exit (pthread_t);
+	extern PBD::Signal4<void,std::string,pthread_t,std::string,uint32_t> ThreadCreatedWithRequestSize;
-
-	extern sigc::signal<void,pthread_t>                                  ThreadLeaving;
-	extern sigc::signal<void,std::string,pthread_t,std::string,uint32_t> ThreadCreatedWithRequestSize;
 }
 
 #endif /* __pbd_pthread_utils__ */

libs/pbd/pbd/signals.h

@@ -103,6 +103,8 @@ public:
 	    return _signal ();
     }
 
+    bool empty() const { return _signal.empty(); }
+    
 private:
     SignalType _signal;
 };
@@ -144,6 +146,8 @@ public:
 	    return _signal (arg1);
     }
     
+    bool empty() const { return _signal.empty(); }
+
 private:
     SignalType _signal;
 };
@@ -184,6 +188,8 @@ public:
 	    return _signal (arg1, arg2);
     }
     
+    bool empty() const { return _signal.empty(); }
+
 private:
     SignalType _signal;
 };
@@ -224,6 +230,50 @@ public:
 	    return _signal (arg1, arg2, arg3);
     }
     
+    bool empty() const { return _signal.empty(); }
+
+private:
+    SignalType _signal;
+};
+
+template<typename R, typename A1, typename A2, typename A3, typename A4>
+class Signal4 {
+public:
+    Signal4 () {}
+    typedef boost::signals2::signal<R(A1,A2,A3,A4)> SignalType;
+
+    void connect_same_thread (ScopedConnectionList& clist, 
+		  const typename SignalType::slot_function_type& slot) {
+	    clist.add_connection (_signal.connect (slot));
+    }
+
+    void connect_same_thread (Connection& c, 
+			      const typename SignalType::slot_function_type& slot) {
+	    c = _signal.connect (slot);
+    }
+
+    static void compositor (typename boost::function<void(A1,A2,A3)> f, PBD::EventLoop* event_loop, A1 arg1, A2 arg2, A3 arg3, A4 arg4) {
+	    event_loop->call_slot (boost::bind (f, arg1, arg2, arg3, arg4));
+    }
+
+    void connect (ScopedConnectionList& clist, 
+		  const typename SignalType::slot_function_type& slot,
+		  PBD::EventLoop* event_loop) {
+	    clist.add_connection (_signal.connect (boost::bind (&compositor, slot, event_loop, _1, _2, _3, _4)));
+    }
+    
+    void connect (Connection& c, 
+		  const typename SignalType::slot_function_type& slot,
+		  PBD::EventLoop* event_loop) {
+	    c = _signal.connect (_signal.connect (boost::bind (&compositor, slot, event_loop, _1, _2, _3, _4)));
+    }
+    
+    typename SignalType::result_type operator()(A1 arg1, A2 arg2, A3 arg3, A4 arg4) {
+	    return _signal (arg1, arg2, arg3, arg4);
+    }
+    
+    bool empty() const { return _signal.empty(); }
+
 private:
     SignalType _signal;
 };

libs/pbd/pthread_utils.cc

@@ -33,11 +33,9 @@ using namespace std;
 typedef std::map<string,pthread_t> ThreadMap;
 static ThreadMap all_threads;
 static pthread_mutex_t thread_map_lock = PTHREAD_MUTEX_INITIALIZER;
-static pthread_mutex_t gui_notify_lock = PTHREAD_MUTEX_INITIALIZER;
 
 namespace PBD {
-	sigc::signal<void,pthread_t>             ThreadLeaving;
+	PBD::Signal4<void,std::string, pthread_t,std::string,uint32_t> ThreadCreatedWithRequestSize;
-	sigc::signal<void,std::string, pthread_t,std::string,uint32_t> ThreadCreatedWithRequestSize;
 }
 
 using namespace PBD;
@@ -54,17 +52,7 @@ static int thread_creator (pthread_t* thread_id, const pthread_attr_t* attr, voi
 void
 PBD::notify_gui_about_thread_creation (std::string target_gui, pthread_t thread, std::string str, int request_count)
 {
-	pthread_mutex_lock (&gui_notify_lock);
 	ThreadCreatedWithRequestSize (target_gui, thread, str, request_count);
-	pthread_mutex_unlock (&gui_notify_lock);
-}
-
-void
-PBD::notify_gui_about_thread_exit (pthread_t thread)
-{
-	pthread_mutex_lock (&gui_notify_lock);
-	ThreadLeaving (thread);
-	pthread_mutex_unlock (&gui_notify_lock);
 }
 
 int  

libs/pbd/undo.cc

@@ -83,7 +83,7 @@ UndoTransaction::add_command (Command *const action)
 	   so there is no need to manage this connection.
 	 */
 
-	action->GoingAway.connect_same_thread (*this, boost::bind (&command_death, this, action));
+	action->DropReferences.connect_same_thread (*this, boost::bind (&command_death, this, action));
 	actions.push_back (action);
 }
 
@@ -186,7 +186,7 @@ UndoHistory::add (UndoTransaction* const ut)
 {
 	uint32_t current_depth = UndoList.size();
 
-	ut->GoingAway.connect_same_thread (*this, boost::bind (&UndoHistory::remove, this, ut));
+	ut->DropReferences.connect_same_thread (*this, boost::bind (&UndoHistory::remove, this, ut));
 
 	/* if the current undo history is larger than or equal to the currently
 	   requested depth, then pop off at least 1 element to make space

libs/surfaces/osc/osc.cc

@@ -578,7 +578,7 @@ OSC::listen_to_route (boost::shared_ptr<Route> route, lo_address addr)
 	*/
 	
 	if (!route_exists) {
-		route->GoingAway.connect (*this, boost::bind (&OSC::drop_route, this, boost::weak_ptr<Route> (route)), this);
+		route->DropReferences.connect (*this, boost::bind (&OSC::drop_route, this, boost::weak_ptr<Route> (route)), this);
 	}
 }