From 7c09916b055332ded9a05dca026d98794856b072 Mon Sep 17 00:00:00 2001
From: Paul Davis <paul@linuxaudiosystems.com>
Date: Fri, 27 Nov 2009 17:29:27 +0000
Subject: [PATCH] switch Route::fed_by from shared_ptr to weak_ptr and thus
 begin to allow Route destructors to be called

git-svn-id: svn://localhost/ardour2/branches/3.0@6189 d708f5d6-7413-0410-9779-e7cbd77b26cf
---
 libs/ardour/ardour/route.h |  2 +-
 libs/ardour/audioengine.cc |  4 ++++
 libs/ardour/session.cc     | 26 ++++++++++++++++++--------
 3 files changed, 23 insertions(+), 9 deletions(-)

diff --git a/libs/ardour/ardour/route.h b/libs/ardour/ardour/route.h
index e3c3a370a9..6c6acb89bd 100644
--- a/libs/ardour/ardour/route.h
+++ b/libs/ardour/ardour/route.h
@@ -268,7 +268,7 @@ class Route : public SessionObject, public AutomatableControls
 	void drop_listen (boost::shared_ptr<Route>);
 
 	bool feeds (boost::shared_ptr<Route>, bool* via_send_only = 0);
-	std::set<boost::shared_ptr<Route> > fed_by;
+	std::set<boost::weak_ptr<Route> > fed_by;
 
 	/* Controls (not all directly owned by the Route */
 
diff --git a/libs/ardour/audioengine.cc b/libs/ardour/audioengine.cc
index b7a37824c9..2e5aea9047 100644
--- a/libs/ardour/audioengine.cc
+++ b/libs/ardour/audioengine.cc
@@ -1115,6 +1115,10 @@ AudioEngine::remove_all_ports ()
 
 		ps->clear ();
 	}
+
+	/* clear dead wood list too */
+
+	ports.flush ();
 }
 
 static void
diff --git a/libs/ardour/session.cc b/libs/ardour/session.cc
index 792029c9cd..67f41a906f 100644
--- a/libs/ardour/session.cc
+++ b/libs/ardour/session.cc
@@ -99,6 +99,7 @@ using namespace std;
 using namespace ARDOUR;
 using namespace PBD;
 using boost::shared_ptr;
+using boost::weak_ptr;
 
 bool Session::_disable_all_loaded_plugins = false;
 
@@ -378,6 +379,12 @@ Session::destroy ()
 	delete _silent_buffers;
 	delete _mix_buffers;
 
+	/* clear out any pending dead wood from RCU managed objects */
+
+	routes.flush ();
+	diskstreams.flush ();
+	_bundles.flush ();
+	
 	AudioDiskstream::free_working_buffers();
 
 	Route::SyncOrderKeys.clear();
@@ -493,9 +500,7 @@ Session::destroy ()
 
 	delete mmc;
 
-	for (vector<void*>::iterator x = debug_pointers.begin(); x != debug_pointers.end(); ++x) {
-		boost_debug_shared_ptr_show (cerr, *x);	
-	}
+	boost_debug_list_ptrs ();
 }
 
 void
@@ -1449,15 +1454,18 @@ trace_terminal (shared_ptr<Route> r1, shared_ptr<Route> rbase)
 
 	/* make a copy of the existing list of routes that feed r1 */
 
-	set<shared_ptr<Route> > existing = r1->fed_by;
+	set<weak_ptr<Route> > existing = r1->fed_by;
 
 	/* for each route that feeds r1, recurse, marking it as feeding
 	   rbase as well.
 	*/
 
-	for (set<shared_ptr<Route> >::iterator i = existing.begin(); i != existing.end(); ++i) {
-		r2 =* i;
-
+	for (set<weak_ptr<Route> >::iterator i = existing.begin(); i != existing.end(); ++i) {
+		if (!(r2 = (*i).lock ())) {
+			/* (*i) went away, ignore it */
+			continue;
+		}
+		
 		/* r2 is a route that feeds r1 which somehow feeds base. mark
 		   base as being fed by r2
 		*/
@@ -1468,7 +1476,7 @@ trace_terminal (shared_ptr<Route> r1, shared_ptr<Route> rbase)
 
 			/* 2nd level feedback loop detection. if r1 feeds or is fed by r2,
 			   stop here.
-			 */
+			*/
 
 			if ((r1->fed_by.find (r2) != r1->fed_by.end()) && (r2->fed_by.find (r1) != r2->fed_by.end())) {
 				continue;
@@ -1512,6 +1520,8 @@ Session::resort_routes_using (shared_ptr<RouteList> r)
 
 	for (i = r->begin(); i != r->end(); ++i) {
 
+		cerr << "\n\n\n CLEAR FED BY for " << (*i)->name() << endl;
+
 		(*i)->fed_by.clear ();
 
 		for (j = r->begin(); j != r->end(); ++j) {