Drop session's monitor bus reference when removing the bus

Since 44610c787 RCU keeps references until another write happens.
even before then, some shared_ptr references may have been kept.

When using a process graph, a route's activision-set can
hold references to other graph-nodes (routes). This lead
to Routes not being deleted until a second graph-reorder
flushed the RCU.

libs/ardour/ardour/graphnode.h

@@ -60,6 +60,7 @@ public:
 
 	node_set_t const& activation_set (GraphChain const* const g) const;
 	int               init_refcount (GraphChain const* const g) const;
+	void              flush_graph_activision_rcu ();
 
 protected:
 	friend struct GraphChain;

libs/ardour/graphnode.cc

@@ -46,6 +46,12 @@ GraphActivision::init_refcount (GraphChain const* const g) const
 	return m->at (g);
 }
 
+void
+GraphActivision::flush_graph_activision_rcu ()
+{
+	_activation_set.flush ();
+}
+
 /* ****************************************************************************/
 
 GraphNode::GraphNode (std::shared_ptr<Graph> graph)

libs/ardour/session.cc

@@ -1101,6 +1101,7 @@ Session::remove_monitor_section ()
 	}
 
 	remove_route (_monitor_out);
+	_monitor_out.reset ();
 	if (deletion_in_progress ()) {
 		return;
 	}
@@ -1410,6 +1411,8 @@ Session::remove_surround_master ()
 	}
 
 	remove_route (_surround_master);
+	_surround_master.reset ();
+
 	if (deletion_in_progress ()) {
 		return;
 	}
@@ -3849,12 +3852,10 @@ Session::remove_routes (std::shared_ptr<RouteList> routes_to_remove)
 	 * going away, then flush old references out of the graph.
 	 */
 
-	routes.flush (); // maybe unsafe, see below.
 	resort_routes ();
 
 	/* get rid of it from the dead wood collection in the route list manager */
 	/* XXX i think this is unsafe as it currently stands, but i am not sure. (pd, october 2nd, 2006) */
-
 	routes.flush ();
 
 	/* remove these routes from the selection if appropriate, and signal
@@ -3882,6 +3883,15 @@ Session::remove_routes (std::shared_ptr<RouteList> routes_to_remove)
 		return;
 	}
 
+	/* really drop reference to the Surround Master to
+	 * unload the vapor plugin. While the RCU keeps a refecent the
+	 * SurroundMaster, a new SurroundMaster cannot be added.
+	 */
+	std::shared_ptr<RouteList const> r = routes.reader ();
+	for (auto const& rt : *r) {
+		rt->flush_graph_activision_rcu ();
+	}
+
 	PropertyChange pc;
 	pc.add (Properties::order);
 	PresentationInfo::Change (pc);

tools/icons/icon.cc

@@ -196,7 +196,10 @@ main (int argc, char** argv)
 
 	sq = ceil (sqrt (ArdourIcon::NoIcon + 3));
 
-	cairo_surface_t* cs = cairo_image_surface_create (CAIRO_FORMAT_ARGB32, 2 * bd + wh * sq, 2 * bd + wh * sq);
+	int w = sq;
+	int h = ceil ((ArdourIcon::NoIcon + 3.0) / sq);
+
+	cairo_surface_t* cs = cairo_image_surface_create (CAIRO_FORMAT_ARGB32, 2 * bd + wh * w, 2 * bd + wh * h);
 	cairo_t*         cr = cairo_create (cs);
 
 	Gtkmm2ext::set_source_rgba (cr, bg_color);
@@ -214,7 +217,7 @@ main (int argc, char** argv)
 	if (bd > 0) {
 		Gtkmm2ext::set_source_rgba (cr, fg_color);
 		cairo_set_line_width (cr, 1);
-		cairo_rectangle (cr, bd - .5, bd - .5, 1 + wh * sq, 1 + wh * sq);
+		cairo_rectangle (cr, bd - .5, bd - .5, 1 + wh * w, 1 + wh * h);
 		cairo_stroke (cr);
 		cairo_set_font_size (cr, fs);
 		for (int rc = 0; rc < sq; ++rc) {
@@ -228,6 +231,10 @@ main (int argc, char** argv)
 					);
 			cairo_show_text (cr, tmp);
 
+			if (rc >= h) {
+				continue;
+			}
+
 			snprintf (tmp, sizeof(tmp), "%d", rc + 1);
 			cairo_text_extents (cr, tmp, &extents);
 			cairo_move_to (cr,

tools/icons/makefile

@@ -1,15 +1,33 @@
 ICONFLAGS?=-g
 
 AD = ../..
-CXXFLAGS = -Wall
+BL = ../../build/libs
+TK = ../../build/libs/tk
+
+CXXFLAGS = -Wall -fsanitize=address
+
 CPPFLAGS = -I $(AD)/libs/gtkmm2ext -I $(AD)/libs/widgets -I $(AD)/libs/pbd -I $(AD)/build/libs/pbd
-CPPFLAGS += `pkg-config --cflags cairo cairomm-1.0 libxml-2.0 glibmm-2.4 gtkmm-2.4`
+CPPFLAGS += -I $(AD)/libs/tk/ydkmm/ydkmm -I $(AD)/libs/tk/ydk/ydk/
+CPPFLAGS += -I $(AD)/libs/tk/ytkmm/ytkmm -I $(AD)/libs/tk/ytk/ytk/
+CPPFLAGS += -I $(AD)/libs/tk/ztkmm/ztkmm/ -I $(AD)/libs/tk/ztk/ztk/
+CPPFLAGS += -I $(AD)/libs/tk/ydk-pixbuf/ydk-pixbuf/
+CPPFLAGS += `pkg-config --cflags cairo pangomm-1.4 cairomm-1.0 libxml-2.0 glibmm-2.4 giomm-2.4`
 
-LDFLAGS = -L$(AD)/build/libs/pbd -Wl,-rpath=$(AD)/build/libs/pbd
-LDFLAGS += -L$(AD)/build/libs/gtkmm2ext -Wl,-rpath=$(AD)/build/libs/gtkmm2ext
-LDFLAGS += -L$(AD)/build/libs/widgets -Wl,-rpath=$(AD)/build/libs/widgets
+LDFLAGS = -L$(BL)/pbd -Wl,-rpath=$(BL)/pbd
+LDFLAGS += -L$(BL)/gtkmm2ext -Wl,-rpath=$(BL)/gtkmm2ext
+LDFLAGS += -L$(BL)/widgets -Wl,-rpath=$(BL)/widgets
 
-LDLIBS = `pkg-config --libs cairo cairomm-1.0 libxml-2.0 glibmm-2.4` -lpbd -lgtkmm2ext -lwidgets
+LDFLAGS += -L$(TK)/ztk -Wl,-rpath=$(TK)/ztk
+LDFLAGS += -L$(TK)/ydk -Wl,-rpath=$(TK)/ydk
+LDFLAGS += -L$(TK)/ytk -Wl,-rpath=$(TK)/ytk
+LDFLAGS += -L$(TK)/ydk-pixbuf -Wl,-rpath=$(TK)/ydk-pixbuf
+LDFLAGS += -L$(TK)/ztkmm -Wl,-rpath=$(TK)/ztkmm
+LDFLAGS += -L$(TK)/ydkmm -Wl,-rpath=$(TK)/ydkmm
+LDFLAGS += -L$(TK)/ytkmm -Wl,-rpath=$(TK)/ytkmm
+
+LDLIBS = `pkg-config --libs cairo cairomm-1.0 libxml-2.0 glibmm-2.4`
+LDLIBS += -lztk -lydk -lytk -lydk-pixbuf -lztkmm -lydkmm -lytkmm
+LDLIBS += -lpbd -lgtkmm2ext -lwidgets
 
 icon: icon.cc libwidgets
 	$(CXX) $(CPPFLAGS) $(CXXFLAGS) $(LDFLAGS) -o $@ icon.cc $(LDLIBS)
@@ -19,10 +37,10 @@ libwidgets:
 
 show: icon
 	rm -f /tmp/ardour_icons-*.png
-	./icon $(ICONFLAGS) -s 22 -o /tmp/ardour_icons-22.png
-	./icon $(ICONFLAGS) -s 23 -o /tmp/ardour_icons-23.png
-	./icon $(ICONFLAGS) -s 44 -o /tmp/ardour_icons-44.png
-	./icon $(ICONFLAGS) -s 45 -o /tmp/ardour_icons-45.png
+	ASAN_OPTIONS=halt_on_error=0 LD_LIBRARY_PATH=$(TK)/ytkmm/:$(TK)/ydkmm:$(TK)/ytk:$(TK)/ydk:$(TK)/ztkmm:$(TK)/ydk-pixbuf:$(TK)/ztk ./icon $(ICONFLAGS) -s 22 -o /tmp/ardour_icons-22.png
+	ASAN_OPTIONS=halt_on_error=0 LD_LIBRARY_PATH=$(TK)/ytkmm/:$(TK)/ydkmm:$(TK)/ytk:$(TK)/ydk:$(TK)/ztkmm:$(TK)/ydk-pixbuf:$(TK)/ztk ./icon $(ICONFLAGS) -s 23 -o /tmp/ardour_icons-23.png
+	ASAN_OPTIONS=halt_on_error=0 LD_LIBRARY_PATH=$(TK)/ytkmm/:$(TK)/ydkmm:$(TK)/ytk:$(TK)/ydk:$(TK)/ztkmm:$(TK)/ydk-pixbuf:$(TK)/ztk ./icon $(ICONFLAGS) -s 44 -o /tmp/ardour_icons-44.png
+	ASAN_OPTIONS=halt_on_error=0 LD_LIBRARY_PATH=$(TK)/ytkmm/:$(TK)/ydkmm:$(TK)/ytk:$(TK)/ydk:$(TK)/ztkmm:$(TK)/ydk-pixbuf:$(TK)/ztk ./icon $(ICONFLAGS) -s 45 -o /tmp/ardour_icons-45.png
 	convert -gravity center \
 		/tmp/ardour_icons-*.png \
 		-background none \