Remove cyclic Source->Playlist references (and with it all dependence on Playlist from Source and children and a bunch of finicky reference managing code).

git-svn-id: svn://localhost/ardour2/branches/3.0@5925 d708f5d6-7413-0410-9779-e7cbd77b26cf

11 files changed, 49 insertions, 123 deletions

diff --git a/libs/ardour/ardour/playlist.h b/libs/ardour/ardour/playlist.h
index aa661b8588..693b2de2dd 100644
--- a/libs/ardour/ardour/playlist.h
+++ b/libs/ardour/ardour/playlist.h
@@ -109,6 +109,8 @@ class Playlist : public SessionObject,
 	boost::shared_ptr<Playlist> copy (std::list<AudioRange>&, bool result_is_hidden = true);
 	int                         paste (boost::shared_ptr<Playlist>, nframes_t position, float times);
 
+	const RegionList& region_list () const { return regions; }
+
 	RegionList*                regions_at (nframes_t frame);
 	RegionList*                regions_touched (nframes_t start, nframes_t end);
 	RegionList*                regions_to_read (nframes_t start, nframes_t end);
diff --git a/libs/ardour/ardour/region.h b/libs/ardour/ardour/region.h
index c1c7ddd5e0..7bae98e573 100644
--- a/libs/ardour/ardour/region.h
+++ b/libs/ardour/ardour/region.h
@@ -177,6 +177,7 @@ class Region
 	bool overlap_equivalent (boost::shared_ptr<const Region>) const;
 	bool region_list_equivalent (boost::shared_ptr<const Region>) const;
 	bool source_equivalent (boost::shared_ptr<const Region>) const;
+	bool uses_source (boost::shared_ptr<const Source>) const;
 
 	/* EDITING OPERATIONS */
 
diff --git a/libs/ardour/ardour/session.h b/libs/ardour/ardour/session.h
index 024b866730..d850fb96d6 100644
--- a/libs/ardour/ardour/session.h
+++ b/libs/ardour/ardour/session.h
@@ -642,6 +642,8 @@ class Session : public PBD::StatefulDestructible, public boost::noncopyable
 	void add_source (boost::shared_ptr<Source>);
 	void remove_source (boost::weak_ptr<Source>);
 
+	uint32_t source_use_count (boost::shared_ptr<const Source> src) const;
+
 	struct cleanup_report {
 		std::vector<std::string> paths;
 		int64_t        space;
diff --git a/libs/ardour/ardour/source.h b/libs/ardour/ardour/source.h
index 1ffca509fd..62aca91365 100644
--- a/libs/ardour/ardour/source.h
+++ b/libs/ardour/ardour/source.h
@@ -35,7 +35,6 @@
 namespace ARDOUR {
 
 class Session;
-class Playlist;
 
 class Source : public SessionObject, public boost::noncopyable
 {
@@ -77,7 +76,7 @@ class Source : public SessionObject, public boost::noncopyable
 
 	XMLNode& get_state ();
 	int set_state (const XMLNode&, int version);
-	
+
 	bool         destructive() const       { return (_flags & Destructive); }
 	bool         writable () const         { return (_flags & Writable); }
 	virtual bool set_destructive (bool /*yn*/) { return false; }
@@ -86,11 +85,6 @@ class Source : public SessionObject, public boost::noncopyable
 	void use ()    { _in_use++; }
 	void disuse () { if (_in_use) { _in_use--; } }
 
-	void add_playlist (boost::shared_ptr<ARDOUR::Playlist>);
-	void remove_playlist (boost::weak_ptr<ARDOUR::Playlist>);
-
-	uint32_t used() const;
-
 	static sigc::signal<void,Source*>             SourceCreated;
 	sigc::signal<void,boost::shared_ptr<Source> > Switched;
 
@@ -123,9 +117,6 @@ class Source : public SessionObject, public boost::noncopyable
 	mutable Glib::Mutex _analysis_lock;
 	Glib::Mutex         _playlist_lock;
 
-	typedef std::map<boost::shared_ptr<ARDOUR::Playlist>, uint32_t > PlaylistMap;
-	PlaylistMap _playlists;
-
   private:
 	uint32_t _in_use;
 	void fix_writable_flags ();
diff --git a/libs/ardour/audio_diskstream.cc b/libs/ardour/audio_diskstream.cc
index 70b4a6bf20..fbd10b92e3 100644
--- a/libs/ardour/audio_diskstream.cc
+++ b/libs/ardour/audio_diskstream.cc
@@ -2305,7 +2305,7 @@ AudioDiskstream::can_become_destructive (bool& requires_bounce) const
 
 	assert (afirst);
 
-	if (afirst->source()->used() > 1) {
+	if (_session.source_use_count (afirst->source()) > 1) {
 		requires_bounce = true;
 		return false;
 	}
diff --git a/libs/ardour/midi_playlist.cc b/libs/ardour/midi_playlist.cc
index 2d042ffb44..a1fb01a7bb 100644
--- a/libs/ardour/midi_playlist.cc
+++ b/libs/ardour/midi_playlist.cc
@@ -119,7 +119,7 @@ MidiPlaylist::read (MidiRingBuffer<nframes_t>& dst, nframes_t start, nframes_t d
 				   on, and remove it from the list we are keeping
 				   around, because we don't need it anymore.
 
-				   if the end of the region (where we want to theoretically resolve notes) 
+				   if the end of the region (where we want to theoretically resolve notes)
 				   is outside the current read range, then just do it at the start
 				   of this read range.
 				*/
@@ -128,7 +128,7 @@ MidiPlaylist::read (MidiRingBuffer<nframes_t>& dst, nframes_t start, nframes_t d
 				if (resolve_at >= end) {
 					resolve_at = start;
 				}
-				
+
 				tracker_info.push_back (TrackerInfo (t->second, resolve_at));
 				DEBUG_TRACE (DEBUG::MidiPlaylistIO, string_compose ("time to resolve & remove tracker for %1 @ %2\n", (*i)->name(), resolve_at));
 				note_cnt += (t->second->on());
diff --git a/libs/ardour/playlist.cc b/libs/ardour/playlist.cc
index a072d4977b..f57093ea40 100644
--- a/libs/ardour/playlist.cc
+++ b/libs/ardour/playlist.cc
@@ -505,7 +505,7 @@ Playlist::add_region (boost::shared_ptr<Region> region, nframes_t position, floa
 
 	nframes_t pos = position;
 
-	if(times == 1 && auto_partition){
+	if (times == 1 && auto_partition){
 		partition(pos, (nframes_t) (pos + region->length()), true);
 	}
 
diff --git a/libs/ardour/region.cc b/libs/ardour/region.cc
index a881d9f1ed..20c87fb1de 100644
--- a/libs/ardour/region.cc
+++ b/libs/ardour/region.cc
@@ -338,17 +338,6 @@ Region::Region (boost::shared_ptr<Source> src, const XMLNode& node)
 
 Region::~Region ()
 {
-	boost::shared_ptr<Playlist> pl (playlist());
-
-	if (pl) {
-		for (SourceList::const_iterator i = _sources.begin(); i != _sources.end(); ++i) {
-			(*i)->remove_playlist (pl);
-		}
-		for (SourceList::const_iterator i = _master_sources.begin(); i != _master_sources.end(); ++i) {
-			(*i)->remove_playlist (pl);
-		}
-	}
-
 	notify_callbacks ();
 	GoingAway (); /* EMIT SIGNAL */
 }
@@ -383,44 +372,7 @@ Region::copy_stuff (boost::shared_ptr<const Region> other, nframes_t /*offset*/,
 void
 Region::set_playlist (boost::weak_ptr<Playlist> wpl)
 {
-	boost::shared_ptr<Playlist> old_playlist = (_playlist.lock());
-
-	boost::shared_ptr<Playlist> pl (wpl.lock());
-
-	if (old_playlist == pl) {
-		return;
-	}
-
-	_playlist = pl;
-
-	if (pl) {
-		if (old_playlist) {
-			for (SourceList::const_iterator i = _sources.begin(); i != _sources.end(); ++i) {
-				(*i)->remove_playlist (_playlist);
-				(*i)->add_playlist (pl);
-			}
-			for (SourceList::const_iterator i = _master_sources.begin(); i != _master_sources.end(); ++i) {
-				(*i)->remove_playlist (_playlist);
-				(*i)->add_playlist (pl);
-			}
-		} else {
-			for (SourceList::const_iterator i = _sources.begin(); i != _sources.end(); ++i) {
-				(*i)->add_playlist (pl);
-			}
-			for (SourceList::const_iterator i = _master_sources.begin(); i != _master_sources.end(); ++i) {
-				(*i)->add_playlist (pl);
-			}
-		}
-	} else {
-		if (old_playlist) {
-			for (SourceList::const_iterator i = _sources.begin(); i != _sources.end(); ++i) {
-				(*i)->remove_playlist (old_playlist);
-			}
-			for (SourceList::const_iterator i = _master_sources.begin(); i != _master_sources.end(); ++i) {
-				(*i)->remove_playlist (old_playlist);
-			}
-		}
-	}
+	_playlist = wpl.lock();
 }
 
 bool
@@ -487,7 +439,7 @@ Region::first_edit ()
 
 	if (_first_edit != EditChangesNothing && pl) {
 
-		_name = pl->session().new_region_name (_name);
+		_name = _session.new_region_name (_name);
 		_first_edit = EditChangesNothing;
 
 		send_change (ARDOUR::NameChanged);
@@ -554,7 +506,7 @@ Region::set_position_lock_style (PositionLockStyle ps)
 	_positional_lock_style = ps;
 
 	if (_positional_lock_style == MusicTime) {
-		pl->session().tempo_map().bbt_time (_position, _bbt_time);
+		_session.tempo_map().bbt_time (_position, _bbt_time);
 	}
 
 }
@@ -568,13 +520,13 @@ Region::update_position_after_tempo_map_change ()
 		return;
 	}
 
-	TempoMap& map (pl->session().tempo_map());
+	TempoMap& map (_session.tempo_map());
 	nframes_t pos = map.frame_time (_bbt_time);
 	set_position_internal (pos, false);
 }
 
 void
-Region::set_position (nframes_t pos, void */*src*/)
+Region::set_position (nframes_t pos, void* /*src*/)
 {
 	if (!can_move()) {
 		return;
@@ -616,7 +568,7 @@ Region::set_position_internal (nframes_t pos, bool allow_bbt_recompute)
 }
 
 void
-Region::set_position_on_top (nframes_t pos, void */*src*/)
+Region::set_position_on_top (nframes_t pos, void* /*src*/)
 {
 	if (_flags & Locked) {
 		return;
@@ -644,15 +596,12 @@ void
 Region::recompute_position_from_lock_style ()
 {
 	if (_positional_lock_style == MusicTime) {
-		boost::shared_ptr<Playlist> pl (playlist());
-		if (pl) {
-			pl->session().tempo_map().bbt_time (_position, _bbt_time);
-		}
+		_session.tempo_map().bbt_time (_position, _bbt_time);
 	}
 }
 
 void
-Region::nudge_position (nframes64_t n, void */*src*/)
+Region::nudge_position (nframes64_t n, void* /*src*/)
 {
 	if (_flags & Locked) {
 		return;
@@ -691,7 +640,7 @@ Region::set_ancestral_data (nframes64_t s, nframes64_t l, float st, float sh)
 }
 
 void
-Region::set_start (nframes_t pos, void */*src*/)
+Region::set_start (nframes_t pos, void* /*src*/)
 {
 	if (_flags & (Locked|PositionLocked)) {
 		return;
@@ -1515,6 +1464,17 @@ Region::source_equivalent (boost::shared_ptr<const Region> other) const
 	return true;
 }
 
+bool
+Region::uses_source (boost::shared_ptr<const Source> source) const
+{
+	for (SourceList::const_iterator i = _sources.begin(); i != _sources.end(); ++i) {
+		if (*i == source) {
+			return true;
+		}
+	}
+	return false;
+}
+
 sframes_t
 Region::source_length(uint32_t n) const
 {
@@ -1596,7 +1556,7 @@ Region::get_parent() const
 		boost::shared_ptr<Region> r;
 		boost::shared_ptr<Region const> grrr2 = boost::dynamic_pointer_cast<Region const> (shared_from_this());
 
-		if (grrr2 && (r = pl->session().find_whole_file_parent (grrr2))) {
+		if (grrr2 && (r = _session.find_whole_file_parent (grrr2))) {
 			return boost::static_pointer_cast<Region> (r);
 		}
 	}
diff --git a/libs/ardour/session.cc b/libs/ardour/session.cc
index 1b054fd6fb..d9c83a3ff3 100644
--- a/libs/ardour/session.cc
+++ b/libs/ardour/session.cc
@@ -3004,6 +3004,23 @@ Session::remove_source (boost::weak_ptr<Source> src)
 	}
 }
 
+/** Return the number of playlists (not regions) that contain @a src */
+uint32_t
+Session::source_use_count (boost::shared_ptr<const Source> src) const
+{
+	uint32_t count = 0;
+	for (PlaylistList::const_iterator p = playlists.begin(); p != playlists.end(); ++p) {
+		for (Playlist::RegionList::const_iterator r = (*p)->region_list().begin();
+				r != (*p)->region_list().end(); ++r) {
+			if ((*r)->uses_source(src)) {
+				++count;
+				break;
+			}
+		}
+	}
+	return count;
+}
+
 boost::shared_ptr<Source>
 Session::source_by_id (const PBD::ID& id)
 {
diff --git a/libs/ardour/session_state.cc b/libs/ardour/session_state.cc
index 83cebbccbe..437699f1e9 100644
--- a/libs/ardour/session_state.cc
+++ b/libs/ardour/session_state.cc
@@ -2503,7 +2503,7 @@ Session::cleanup_sources (Session::cleanup_report& rep)
 		   capture files.
 		*/
 
-		if (!i->second->used() && i->second->length(i->second->timeline_position()) > 0) {
+		if (!source_use_count(i->second) && i->second->length(i->second->timeline_position()) > 0) {
 			dead_sources.push_back (i->second);
 			i->second->GoingAway();
 		}
diff --git a/libs/ardour/source.cc b/libs/ardour/source.cc
index 4efd154dcd..0304bfea8a 100644
--- a/libs/ardour/source.cc
+++ b/libs/ardour/source.cc
@@ -36,7 +36,6 @@
 #include "pbd/pthread_utils.h"
 #include "pbd/enumwriter.h"
 
-#include "ardour/playlist.h"
 #include "ardour/session.h"
 #include "ardour/source.h"
 #include "ardour/transient_detector.h"
@@ -149,52 +148,6 @@ Source::set_state (const XMLNode& node, int /*version*/)
 	return 0;
 }
 
-void
-Source::add_playlist (boost::shared_ptr<Playlist> pl)
-{
-	std::pair<PlaylistMap::iterator,bool> res;
-	std::pair<boost::shared_ptr<Playlist>, uint32_t> newpair (pl, 1);
-	Glib::Mutex::Lock lm (_playlist_lock);
-
-	res = _playlists.insert (newpair);
-
-	if (!res.second) {
-		/* it already existed, bump count */
-		res.first->second++;
-	}
-
-	pl->GoingAway.connect (bind (
-			mem_fun (*this, &Source::remove_playlist),
-			boost::weak_ptr<Playlist> (pl)));
-}
-
-void
-Source::remove_playlist (boost::weak_ptr<Playlist> wpl)
-{
-	boost::shared_ptr<Playlist> pl (wpl.lock());
-
-	if (!pl) {
-		return;
-	}
-
-	PlaylistMap::iterator x;
-	Glib::Mutex::Lock lm (_playlist_lock);
-
-	if ((x = _playlists.find (pl)) != _playlists.end()) {
-		if (x->second > 1) {
-			x->second--;
-		} else {
-			_playlists.erase (x);
-		}
-	}
-}
-
-uint32_t
-Source::used () const
-{
-	return _playlists.size();
-}
-
 bool
 Source::has_been_analysed() const
 {