Fix lost MIDI note offs and controllers.

Fix initial read of discrete MIDI controllers.

Fix spurious note offs when starting to play in the middle of a note.

Faster search for initial event when cached iterator is invalid.

So much for dropping the cached iterator.  The iterator is responsible for
handling note offs, so that doesn't work.  This design means we have some stuck
note issues at the source read level, but they should be taken care of by the
state tracker anyway.

libs/ardour/ardour/midi_source.h

@@ -140,6 +140,11 @@ class LIBARDOUR_API MidiSource : virtual public Source, public boost::enable_sha
 	virtual void load_model(bool lock=true, bool force_reload=false) = 0;
 	virtual void destroy_model() = 0;
 
+	/** This must be called with the source lock held whenever the
+	 *  source/model contents have been changed (reset iterators/cache/etc).
+	 */
+	void invalidate();
+
 	void set_note_mode(NoteMode mode);
 
 	boost::shared_ptr<MidiModel> model() { return _model; }
@@ -186,7 +191,11 @@ class LIBARDOUR_API MidiSource : virtual public Source, public boost::enable_sha
 	boost::shared_ptr<MidiModel> _model;
 	bool                         _writing;
 
-	mutable double _length_beats;
+	mutable Evoral::Sequence<Evoral::MusicalTime>::const_iterator _model_iter;
+	mutable bool                                                  _model_iter_valid;
+
+	mutable double     _length_beats;
+	mutable framepos_t _last_read_end;
 
 	/** The total duration of the current capture. */
 	framepos_t _capture_length;

libs/ardour/midi_model.cc

@@ -1630,6 +1630,7 @@ MidiModel::edit_lock()
 	assert (ms);
 
 	Glib::Threads::Mutex::Lock* source_lock = new Glib::Threads::Mutex::Lock (ms->mutex());
+	ms->invalidate(); // Release cached iterator's read lock on model
 	return WriteLock(new WriteLockImpl(source_lock, _lock, _control_lock));
 }
 
@@ -1853,6 +1854,10 @@ MidiModel::set_midi_source (boost::shared_ptr<MidiSource> s)
 {
 	boost::shared_ptr<MidiSource> old = _midi_source.lock ();
 
+	if (old) {
+		old->invalidate ();
+	}
+
 	_midi_source_connections.drop_connections ();
 
 	_midi_source = s;

libs/ardour/midi_region.cc

@@ -421,6 +421,13 @@ MidiRegion::model_automation_state_changed (Evoral::Parameter const & p)
 	} else {
 		_filtered_parameters.insert (p);
 	}
+
+	/* the source will have an iterator into the model, and that iterator will have been set up
+	   for a given set of filtered_parameters, so now that we've changed that list we must invalidate
+	   the iterator.
+	*/
+	Glib::Threads::Mutex::Lock lm (midi_source(0)->mutex());
+	midi_source(0)->invalidate ();
 }
 
 /** This is called when a trim drag has resulted in a -ve _start time for this region.

libs/ardour/midi_source.cc

@@ -56,7 +56,9 @@ PBD::Signal1<void,MidiSource*> MidiSource::MidiSourceCreated;
 MidiSource::MidiSource (Session& s, string name, Source::Flag flags)
 	: Source(s, DataType::MIDI, name, flags)
 	, _writing(false)
+	, _model_iter_valid(false)
 	, _length_beats(0.0)
+	, _last_read_end(0)
 	, _capture_length(0)
 	, _capture_loop_length(0)
 {
@@ -65,7 +67,9 @@ MidiSource::MidiSource (Session& s, string name, Source::Flag flags)
 MidiSource::MidiSource (Session& s, const XMLNode& node)
 	: Source(s, node)
 	, _writing(false)
+	, _model_iter_valid(false)
 	, _length_beats(0.0)
+	, _last_read_end(0)
 	, _capture_length(0)
 	, _capture_loop_length(0)
 {
@@ -169,6 +173,13 @@ MidiSource::update_length (framecnt_t)
 	// You're not the boss of me!
 }
 
+void
+MidiSource::invalidate ()
+{
+	_model_iter_valid = false;
+	_model_iter.invalidate();
+}
+
 framecnt_t
 MidiSource::midi_read (Evoral::EventSink<framepos_t>&     dst,
                        framepos_t                         source_start,
@@ -186,11 +197,18 @@ MidiSource::midi_read (Evoral::EventSink<framepos_t>&     dst,
 	                             source_start, start, cnt, tracker, name()));
 
 	if (_model) {
-		// Read events up to end
-		const double start_beats = converter.from(start);
-		for (Evoral::Sequence<double>::const_iterator i = _model->begin(start_beats, false, filtered);
-		     i != _model->end();
-		     ++i) {
+		// Find appropriate model iterator
+		Evoral::Sequence<double>::const_iterator& i = _model_iter;
+		if (_last_read_end == 0 || start != _last_read_end || !_model_iter_valid) {
+			// Cached iterator is invalid, search for the first event past start
+			i                 = _model->begin(converter.from(start), false, filtered);
+			_model_iter_valid = true;
+		}
+
+		_last_read_end = start + cnt;
+
+		// Copy events in [start, start + cnt) into dst
+		for (; i != _model->end(); ++i) {
 			const framecnt_t time_frames = converter.to(i->time());
 			if (time_frames < start + cnt) {
 				// Offset by source start to convert event time to session time
@@ -225,7 +243,10 @@ MidiSource::midi_write (MidiRingBuffer<framepos_t>& source,
 
 	const framecnt_t ret = write_unlocked (source, source_start, cnt);
 
-	if (cnt != max_framecnt) {
+	if (cnt == max_framecnt) {
+		_last_read_end = 0;
+		invalidate();
+	} else {
 		_capture_length += cnt;
 	}
 

libs/ardour/smf_source.cc

@@ -701,6 +701,7 @@ SMFSource::load_model (bool lock, bool force_reload)
 
 	_model->end_write (Evoral::Sequence<Evoral::MusicalTime>::ResolveStuckNotes, _length_beats);
 	_model->set_edited (false);
+	invalidate();
 
 	free(buf);
 }
@@ -724,6 +725,8 @@ SMFSource::flush_midi ()
 	Evoral::SMF::end_write ();
 	/* data in the file means its no longer removable */
 	mark_nonremovable ();
+
+	invalidate();
 }
 
 void

libs/evoral/src/Sequence.cpp

@@ -61,10 +61,13 @@ namespace Evoral {
 template<typename Time>
 Sequence<Time>::const_iterator::const_iterator()
 	: _seq(NULL)
+	, _event(boost::shared_ptr< Event<Time> >(new Event<Time>()))
+	, _active_patch_change_message (0)
+	, _type(NIL)
 	, _is_end(true)
 	, _control_iter(_control_iters.end())
+	, _force_discrete(false)
 {
-	_event = boost::shared_ptr< Event<Time> >(new Event<Time>());
 }
 
 /** @param force_discrete true to force ControlLists to use discrete evaluation, otherwise false to get them to use their configured mode */
@@ -125,7 +128,7 @@ Sequence<Time>::const_iterator::const_iterator(const Sequence<Time>& seq, Time t
 		DEBUG_TRACE (DEBUG::Sequence, string_compose ("Iterator: control: %1\n", seq._type_map.to_symbol(i->first)));
 		double x, y;
 		bool ret;
-		if (_force_discrete) {
+		if (_force_discrete || i->second->list()->interpolation() == ControlList::Discrete) {
 			ret = i->second->list()->rt_safe_earliest_event_discrete_unlocked (t, x, y, true);
 		} else {
 			ret = i->second->list()->rt_safe_earliest_event_unlocked(t, x, y, true);
@@ -290,12 +293,10 @@ Sequence<Time>::const_iterator::operator++()
 		// Increment current controller iterator
 		if (_force_discrete || _control_iter->list->interpolation() == ControlList::Discrete) {
 			ret = _control_iter->list->rt_safe_earliest_event_discrete_unlocked (
-				_control_iter->x, x, y, false
-			                                                                     );
+				_control_iter->x, x, y, false);
 		} else {
 			ret = _control_iter->list->rt_safe_earliest_event_linear_unlocked (
-				_control_iter->x + time_between_interpolated_controller_outputs, x, y, false
-			                                                                   );
+				_control_iter->x + time_between_interpolated_controller_outputs, x, y, false);
 		}
 		assert(!ret || x > _control_iter->x);
 		if (ret) {