From cb567dd8818cf4d871a1f77385a3ce8f8c1f91ed Mon Sep 17 00:00:00 2001
From: Paul Davis <paul@linuxaudiosystems.com>
Date: Thu, 3 Nov 2016 10:44:17 +0000
Subject: [PATCH] remove complex iterator from Evoral::Sequence and replace
 with wrapping a normal std::multiset iterator

---
 libs/ardour/ardour/midi_source.h |   1 -
 libs/ardour/midi_model.cc        |   6 +-
 libs/ardour/midi_region.cc       |   7 +-
 libs/ardour/midi_source.cc       | 183 +++++---------
 libs/ardour/midi_stretch.cc      |   2 +-
 libs/evoral/evoral/Sequence.hpp  |  92 ++-----
 libs/evoral/src/Sequence.cpp     | 405 +------------------------------
 7 files changed, 90 insertions(+), 606 deletions(-)

diff --git a/libs/ardour/ardour/midi_source.h b/libs/ardour/ardour/midi_source.h
index 29f88773a9..731fd1d835 100644
--- a/libs/ardour/ardour/midi_source.h
+++ b/libs/ardour/ardour/midi_source.h
@@ -236,7 +236,6 @@ class LIBARDOUR_API MidiSource : virtual public Source, public boost::enable_sha
 	mutable bool                                            _model_iter_valid;
 
 	mutable Evoral::Beats _length_beats;
-	mutable framepos_t    _last_read_end;
 
 	/** The total duration of the current capture. */
 	framepos_t _capture_length;
diff --git a/libs/ardour/midi_model.cc b/libs/ardour/midi_model.cc
index d410b1ab3e..e50a3678ef 100644
--- a/libs/ardour/midi_model.cc
+++ b/libs/ardour/midi_model.cc
@@ -1428,7 +1428,7 @@ MidiModel::write_to (boost::shared_ptr<MidiSource>     source,
 	source->drop_model(source_lock);
 	source->mark_streaming_midi_write_started (source_lock, note_mode());
 
-	for (Evoral::Sequence<TimeType>::const_iterator i = begin(TimeType(), true); i != end(); ++i) {
+	for (Evoral::Sequence<TimeType>::const_iterator i = begin (); i != end(); ++i) {
 		source->append_event_beats(source_lock, *i);
 	}
 
@@ -1466,7 +1466,7 @@ MidiModel::sync_to_source (const Glib::Threads::Mutex::Lock& source_lock)
 
 	ms->mark_streaming_midi_write_started (source_lock, note_mode());
 
-	for (Evoral::Sequence<TimeType>::const_iterator i = begin(TimeType(), true); i != end(); ++i) {
+	for (Evoral::Sequence<TimeType>::const_iterator i = begin (); i != end(); ++i) {
 		ms->append_event_beats(source_lock, *i);
 	}
 
@@ -1501,7 +1501,7 @@ MidiModel::write_section_to (boost::shared_ptr<MidiSource>     source,
 	source->drop_model(source_lock);
 	source->mark_streaming_midi_write_started (source_lock, note_mode());
 
-	for (Evoral::Sequence<TimeType>::const_iterator i = begin(TimeType(), true); i != end(); ++i) {
+	for (Evoral::Sequence<TimeType>::const_iterator i = begin (); i != end(); ++i) {
 		if (i->time() >= begin_time && i->time() < end_time) {
 
 			Evoral::MIDIEvent<TimeType> mev (*i, true); /* copy the event */
diff --git a/libs/ardour/midi_region.cc b/libs/ardour/midi_region.cc
index a2838bdc55..1ce304ce37 100644
--- a/libs/ardour/midi_region.cc
+++ b/libs/ardour/midi_region.cc
@@ -421,8 +421,7 @@ MidiRegion::_read_at (const SourceList&              /*srcs*/,
 	     << " _start = " << _start
 	     << " intoffset = " << internal_offset
 	     << " pulse = " << pulse()
-	     << " start_pulse = " << start_pulse()
-	     << " start_beat = " << _start_beats
+	     << " beat = " << _start_beats
 	     << endl;
 #endif
 
@@ -438,8 +437,8 @@ MidiRegion::_read_at (const SourceList&              /*srcs*/,
 		    tracker,
 		    filter,
 		    _filtered_parameters,
-		    pulse(),
-		    _start_beats
+		    pulse(), // position of region in musical time
+		    _start_beats // offset into source file in musical time
 		    ) != to_read) {
 		return 0; /* "read nothing" */
 	}
diff --git a/libs/ardour/midi_source.cc b/libs/ardour/midi_source.cc
index a770a2c290..ae2589f1cb 100644
--- a/libs/ardour/midi_source.cc
+++ b/libs/ardour/midi_source.cc
@@ -63,7 +63,6 @@ MidiSource::MidiSource (Session& s, string name, Source::Flag flags)
 	, _writing(false)
 	, _model_iter_valid(false)
 	, _length_beats(0.0)
-	, _last_read_end(0)
 	, _capture_length(0)
 	, _capture_loop_length(0)
 {
@@ -74,7 +73,6 @@ MidiSource::MidiSource (Session& s, const XMLNode& node)
 	, _writing(false)
 	, _model_iter_valid(false)
 	, _length_beats(0.0)
-	, _last_read_end(0)
 	, _capture_length(0)
 	, _capture_loop_length(0)
 {
@@ -182,151 +180,91 @@ void
 MidiSource::invalidate (const Lock& lock, std::set<Evoral::Sequence<Evoral::Beats>::WeakNotePtr>* notes)
 {
 	_model_iter_valid = false;
-	_model_iter.invalidate(notes);
+	//_model_iter.invalidate(notes);
 }
 
 framecnt_t
 MidiSource::midi_read (const Lock&                        lm,
                        Evoral::EventSink<framepos_t>&     dst,
-                       framepos_t                         source_start,
-                       framepos_t                         start,
+                       framepos_t                         source_start, // position of source origin (samples)
+                       framepos_t                         start,        // first position to read (samples)
                        framecnt_t                         cnt,
                        Evoral::Range<framepos_t>*         loop_range,
                        MidiStateTracker*                  tracker,
                        MidiChannelFilter*                 filter,
                        const std::set<Evoral::Parameter>& filtered,
-		       const double                       pulse,
-		       const double                       start_beats) const
+                       const double                       pulse, // position of start of region in musical time
+                       const double                       start_beats // offset into data in musical time (equivalent to _start above)
+	) const
 {
-	//BeatsFramesConverter converter(_session.tempo_map(), source_start);
-	const int32_t tpb = Timecode::BBT_Time::ticks_per_beat;
-	const double pulse_tick_res = floor ((pulse * 4.0 * tpb) + 0.5) / tpb;
-	const double start_qn = (pulse * 4.0) - start_beats;
-
-	DEBUG_TRACE (DEBUG::MidiSourceIO,
-	             string_compose ("MidiSource::midi_read() %5 sstart %1 start %2 cnt %3 tracker %4\n",
-	                             source_start, start, cnt, tracker, name()));
 
 	if (!_model) {
 		return read_unlocked (lm, dst, source_start, start, cnt, loop_range, tracker, filter);
 	}
 
-	// Find appropriate model iterator
-	Evoral::Sequence<Evoral::Beats>::const_iterator& i = _model_iter;
-	const bool linear_read = _last_read_end != 0 && start == _last_read_end;
-	if (!linear_read || !_model_iter_valid) {
+	/* Events in the model are timestamped relative to the start of the model (zero).
+	 * We're looking for events in the model corresponding to events on a given section of the
+	 * timeline. Unless the start of the model (zero) is at the the origin of the timeline,
+	 * these two time coordinates are displaced from each other. So we need to compute
+	 * the relative displacement, and then look for the correct events.
+	 *
+	 * start on timeline (samples): start
+	 * source start on timeline (musical): start of region - start_offset_of_region_within_file
+	 * convert start
+	 * compute different in musical time
+	 */
+
+	const int32_t tpb = Timecode::BBT_Time::ticks_per_beat;
+	const double pulse_tick_res = floor ((pulse * 4.0 * tpb) + 0.5) / tpb;
+
+	/* musical time position of start of source */
+
+	const TimeType start_qn ((pulse * 4.0) - start_beats);
+	const TimeType read_start_qn (_session.tempo_map().exact_beat_at_frame (start, 0));
+	const TimeType read_end_qn (_session.tempo_map().exact_beat_at_frame (start+cnt, 0));
+	const TimeType first_possible_event_time = read_start_qn - start_qn;
+	const TimeType last_possible_event_time = read_end_qn - start_qn;
+
+	DEBUG_TRACE (DEBUG::MidiSourceIO,
+	             string_compose ("MidiSource::midi_read() %5 sstart %1 start %2 (qn = %5) cnt %3 tracker %4\n",
+	                             source_start, start, cnt, tracker, name(), start_qn));
+
+	for (MidiModel::const_iterator i = _model->lower_bound (first_possible_event_time); i != _model->end() && i->time() < last_possible_event_time; ++i) {
+
 #if 0
-		// Cached iterator is invalid, search for the first event past start
-		i = _model->begin(converter.from(start), false, filtered,
-		                  linear_read ? &_model->active_notes() : NULL);
-		_model_iter_valid = true;
-		if (!linear_read) {
-			_model->active_notes().clear();
-		}
-#else
-		/* hot-fix http://tracker.ardour.org/view.php?id=6541
-		 * "parallel playback of linked midi regions -> no note-offs"
-		 *
-		 * A midi source can be used by multiple tracks simultaneously,
-		 * in which case midi_read() may be called from different tracks for
-		 * overlapping time-ranges.
-		 *
-		 * However there is only a single iterator for a given midi-source.
-		 * This results in every midi_read() performing a seek.
-		 *
-		 * If seeking is performed with
-		 *    _model->begin(converter.from(start),...)
-		 * the model is used for seeking. That method seeks to the first
-		 * *note-on* event after 'start'.
-		 *
-		 * _model->begin(converter.from(  ) ,..) eventually calls
-		 * Sequence<Time>::const_iterator() in libs/evoral/src/Sequence.cpp
-		 * which looks up the note-event via seq.note_lower_bound(t);
-		 * but the sequence 'seq' only contains note-on events(!).
-		 * note-off events are implicit in Sequence<Time>::operator++()
-		 * via _active_notes.pop(); and not part of seq.
-		 *
-		 * see also http://tracker.ardour.org/view.php?id=6287#c16671
-		 *
-		 * The linear search below assures that reading starts at the first
-		 * event for the given time, regardless of its event-type.
-		 *
-		 * The performance of this approach is O(N), while the previous
-		 * implementation is O(log(N)). This needs to be optimized:
-		 * The model-iterator or event-sequence needs to be re-designed in
-		 * some way (maybe keep an iterator per playlist).
-		 */
-		for (i = _model->begin(); i != _model->end(); ++i) {
-			if (floor (((i->time().to_double() + start_qn) * tpb) + 0.5) / tpb >= pulse_tick_res) {
-				break;
-			}
-		}
-		_model_iter_valid = true;
-		if (!linear_read) {
-			_model->active_notes().clear();
-		}
-#endif
-	}
-
-	_last_read_end = start + cnt;
-
-	// Copy events in [start, start + cnt) into dst
-	for (; i != _model->end(); ++i) {
-
-		// Offset by source start to convert event time to session time
-
-		framecnt_t time_frames = _session.tempo_map().frame_at_quarter_note (i->time().to_double() + start_qn);
-
-		if (time_frames < (start + source_start)) {
-
-			/* event too early */
-
-			continue;
-
-		} else if (time_frames >= start + cnt + source_start) {
-
+		if (filter && filter->filter(i->buffer(), i->size())) {
 			DEBUG_TRACE (DEBUG::MidiSourceIO,
-			             string_compose ("%1: reached end with event @ %2 vs. %3\n",
-			                             _name, time_frames, start+cnt));
-			break;
+			             string_compose ("%1: filter event @ %2 type %3 size %4\n",
+			                             _name, i->time(), i->event_type(), i->size()));
+			continue;
+		}
 
-		} else {
+		if (loop_range) {
+			// time_frames = loop_range->squish (time_frames);
+		}
 
-			/* in range */
-
-			if (filter && filter->filter(i->buffer(), i->size())) {
-				DEBUG_TRACE (DEBUG::MidiSourceIO,
-				             string_compose ("%1: filter event @ %2 type %3 size %4\n",
-				                             _name, time_frames, i->event_type(), i->size()));
-				continue;
-			}
-
-			if (loop_range) {
-				time_frames = loop_range->squish (time_frames);
-			}
-
-			dst.write (time_frames, i->event_type(), i->size(), i->buffer());
+		// dst.write (time_frames, i->event_type(), i->size(), i->buffer());
 
 #ifndef NDEBUG
-			if (DEBUG_ENABLED(DEBUG::MidiSourceIO)) {
-				DEBUG_STR_DECL(a);
-				DEBUG_STR_APPEND(a, string_compose ("%1 added event @ %2 sz %3 within %4 .. %5 ",
-				                                    _name, time_frames, i->size(),
-				                                    start + source_start, start + cnt + source_start));
-				for (size_t n=0; n < i->size(); ++n) {
-					DEBUG_STR_APPEND(a,hex);
-					DEBUG_STR_APPEND(a,"0x");
-					DEBUG_STR_APPEND(a,(int)i->buffer()[n]);
-					DEBUG_STR_APPEND(a,' ');
-				}
-				DEBUG_STR_APPEND(a,'\n');
-				DEBUG_TRACE (DEBUG::MidiSourceIO, DEBUG_STR(a).str());
+		if (DEBUG_ENABLED(DEBUG::MidiSourceIO)) {
+			DEBUG_STR_DECL(a);
+			DEBUG_STR_APPEND(a, string_compose ("%1 added event @ %2 sz %3 within %4 .. %5 ",
+			                                    _name, time_frames, i->size(),
+			                                    start + source_start, start + cnt + source_start));
+			for (size_t n=0; n < i->size(); ++n) {
+				DEBUG_STR_APPEND(a,hex);
+				DEBUG_STR_APPEND(a,"0x");
+				DEBUG_STR_APPEND(a,(int)i->buffer()[n]);
+				DEBUG_STR_APPEND(a,' ');
 			}
+			DEBUG_STR_APPEND(a,'\n');
+			DEBUG_TRACE (DEBUG::MidiSourceIO, DEBUG_STR(a).str());
+		}
 #endif
 
-			if (tracker) {
-				tracker->track (*i);
-			}
+#endif
+		if (tracker) {
+			tracker->track (*i);
 		}
 	}
 
@@ -342,7 +280,6 @@ MidiSource::midi_write (const Lock&                 lm,
 	const framecnt_t ret = write_unlocked (lm, source, source_start, cnt);
 
 	if (cnt == max_framecnt) {
-		_last_read_end = 0;
 		invalidate(lm);
 	} else {
 		_capture_length += cnt;
diff --git a/libs/ardour/midi_stretch.cc b/libs/ardour/midi_stretch.cc
index 70f44e19c1..12372bb7c7 100644
--- a/libs/ardour/midi_stretch.cc
+++ b/libs/ardour/midi_stretch.cc
@@ -98,7 +98,7 @@ MidiStretch::run (boost::shared_ptr<Region> r, Progress*)
 	/* Note: pass true into force_discrete for the begin() iterator so that the model doesn't
 	 * do interpolation of controller data when we stretch.
 	 */
-	for (Evoral::Sequence<MidiModel::TimeType>::const_iterator i = old_model->begin (MidiModel::TimeType(), true);
+	for (Evoral::Sequence<MidiModel::TimeType>::const_iterator i = old_model->begin ();
 			i != old_model->end(); ++i) {
 		const MidiModel::TimeType new_time = i->time() * (double)_request.time_fraction;
 
diff --git a/libs/evoral/evoral/Sequence.hpp b/libs/evoral/evoral/Sequence.hpp
index 104b9ac541..84c59c0fd8 100644
--- a/libs/evoral/evoral/Sequence.hpp
+++ b/libs/evoral/evoral/Sequence.hpp
@@ -62,11 +62,11 @@ public:
  * Controller data is represented as a list of time-stamped float values. */
 template<typename Time>
 class LIBEVORAL_API Sequence : virtual public ControlSet {
-public:
+  public:
 	Sequence(const TypeMap& type_map);
 	Sequence(const Sequence<Time>& other);
 
-protected:
+  protected:
 	struct WriteLockImpl {
 		WriteLockImpl(Glib::Threads::RWLock& s, Glib::Threads::Mutex& c)
 			: sequence_lock(new Glib::Threads::RWLock::WriterLock(s))
@@ -79,7 +79,22 @@ protected:
 		Glib::Threads::Mutex::Lock*        control_lock;
 	};
 
-public:
+  public:
+	struct EventTimeComparator {
+		bool operator() (Event<Time> const & a, Event<Time> const & b) const {
+			return a.time() < b.time();
+		}
+	};
+
+	typedef typename std::multiset<Evoral::Event<Time>,EventTimeComparator> Events;
+	typedef typename Events::const_iterator const_iterator;
+
+  private:
+	Events       _events;      // all events, indexed by time
+
+  public:
+	inline size_t n_events () const { return _events.size(); }
+	inline size_t empty () const { return _events.empty(); }
 
 	typedef typename boost::shared_ptr<Evoral::Note<Time> >       NotePtr;
 	typedef typename boost::weak_ptr<Evoral::Note<Time> >         WeakNotePtr;
@@ -112,7 +127,6 @@ public:
 	const TypeMap& type_map() const { return _type_map; }
 
 	inline size_t n_notes() const { return _notes.size(); }
-	inline bool   empty()   const { return _notes.empty() && _sysexes.empty() && _patch_changes.empty() && ControlSet::controls_empty(); }
 
 	inline static bool note_time_comparator(const boost::shared_ptr< const Note<Time> >& a,
 	                                        const boost::shared_ptr< const Note<Time> >& b) {
@@ -207,68 +221,10 @@ public:
 private:
 	typedef std::priority_queue<NotePtr, std::deque<NotePtr>, LaterNoteEndComparator> ActiveNotes;
 public:
+	const_iterator begin () const { return _events.begin(); }
+	const const_iterator end() const { return _events.end(); }
 
-	/** Read iterator */
-	class LIBEVORAL_API const_iterator {
-	public:
-		const_iterator();
-		const_iterator(const Sequence<Time>&              seq,
-		               Time                               t,
-		               bool                               force_discrete,
-		               const std::set<Evoral::Parameter>& filtered,
-		               const std::set<WeakNotePtr>*       active_notes=NULL);
-
-		inline bool valid() const { return !_is_end && _event; }
-
-		void invalidate(std::set<WeakNotePtr>* notes);
-
-		const Event<Time>& operator*()  const { return *_event;  }
-		const boost::shared_ptr< Event<Time> > operator->() const  { return _event; }
-		const boost::shared_ptr< Event<Time> > get_event_pointer() { return _event; }
-
-		const const_iterator& operator++(); // prefix only
-
-		bool operator==(const const_iterator& other) const;
-		bool operator!=(const const_iterator& other) const { return ! operator==(other); }
-
-		const_iterator& operator=(const const_iterator& other);
-
-	private:
-		friend class Sequence<Time>;
-
-		Time choose_next(Time earliest_t);
-		void set_event();
-
-		typedef std::vector<ControlIterator> ControlIterators;
-		enum MIDIMessageType { NIL, NOTE_ON, NOTE_OFF, CONTROL, SYSEX, PATCH_CHANGE };
-
-		const Sequence<Time>*                 _seq;
-		boost::shared_ptr< Event<Time> >      _event;
-		mutable ActiveNotes                   _active_notes;
-		/** If the iterator is pointing at a patch change, this is the index of the
-		 *  sub-message within that change.
-		 */
-		int                                   _active_patch_change_message;
-		MIDIMessageType                       _type;
-		bool                                  _is_end;
-		typename Sequence::ReadLock           _lock;
-		typename Notes::const_iterator        _note_iter;
-		typename SysExes::const_iterator      _sysex_iter;
-		typename PatchChanges::const_iterator _patch_change_iter;
-		ControlIterators                      _control_iters;
-		ControlIterators::iterator            _control_iter;
-		bool                                  _force_discrete;
-	};
-
-	const_iterator begin (
-		Time                               t              = Time(),
-		bool                               force_discrete = false,
-		const std::set<Evoral::Parameter>& f              = std::set<Evoral::Parameter>(),
-		const std::set<WeakNotePtr>*       active_notes   = NULL) const {
-		return const_iterator (*this, t, force_discrete, f, active_notes);
-	}
-
-	const const_iterator& end() const { return _end_iter; }
+	const_iterator lower_bound (Time t) const { Event<Time> ev (0, t, 0, 0, false); return _events.lower_bound (ev); }
 
 	// CONST iterator implementations (x3)
 	typename Notes::const_iterator note_lower_bound (Time t) const;
@@ -321,8 +277,6 @@ protected:
 	virtual void control_list_marked_dirty ();
 
 private:
-	friend class const_iterator;
-
 	bool overlaps_unlocked (const NotePtr& ev, const NotePtr& ignore_this_note) const;
 	bool contains_unlocked (const NotePtr& ev) const;
 
@@ -338,7 +292,7 @@ private:
 	const TypeMap& _type_map;
 
 	Notes        _notes;       // notes indexed by time
-	Pitches      _pitches[16]; // notes indexed by channel+pitch
+	Pitches      _pitches[16]; // notes indexed by pitch, but also channel via array index
 	SysExes      _sysexes;
 	PatchChanges _patch_changes;
 
@@ -351,7 +305,6 @@ private:
 	 */
 	int _bank[16];
 
-	const   const_iterator _end_iter;
 	bool                   _percussive;
 
 	uint8_t _lowest_note;
@@ -365,4 +318,3 @@ template<typename Time> /*LIBEVORAL_API*/ std::ostream& operator<<(std::ostream&
 
 
 #endif // EVORAL_SEQUENCE_HPP
-
diff --git a/libs/evoral/src/Sequence.cpp b/libs/evoral/src/Sequence.cpp
index c578a9ebec..2c9e64c5fc 100644
--- a/libs/evoral/src/Sequence.cpp
+++ b/libs/evoral/src/Sequence.cpp
@@ -57,403 +57,6 @@ static double const time_between_interpolated_controller_outputs = 1.0 / 256;
 
 namespace Evoral {
 
-// Read iterator (const_iterator)
-
-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)
-{
-}
-
-/** @param force_discrete true to force ControlLists to use discrete evaluation, otherwise false to get them to use their configured mode */
-template<typename Time>
-Sequence<Time>::const_iterator::const_iterator(const Sequence<Time>&              seq,
-                                               Time                               t,
-                                               bool                               force_discrete,
-                                               const std::set<Evoral::Parameter>& filtered,
-                                               const std::set<WeakNotePtr>*       active_notes)
-	: _seq(&seq)
-	, _active_patch_change_message (0)
-	, _type(NIL)
-	, _is_end((t == DBL_MAX) || seq.empty())
-	, _note_iter(seq.notes().end())
-	, _sysex_iter(seq.sysexes().end())
-	, _patch_change_iter(seq.patch_changes().end())
-	, _control_iter(_control_iters.end())
-	, _force_discrete (force_discrete)
-{
-	DEBUG_TRACE (DEBUG::Sequence, string_compose ("Created Iterator @ %1 (is end: %2)\n)", t, _is_end));
-
-	if (_is_end) {
-		return;
-	}
-
-	_lock = seq.read_lock();
-
-	// Add currently active notes, if given
-	if (active_notes) {
-		for (typename std::set<WeakNotePtr>::const_iterator i = active_notes->begin();
-		     i != active_notes->end(); ++i) {
-			NotePtr note = i->lock();
-			if (note && note->time() <= t && note->end_time() > t) {
-				_active_notes.push(note);
-			}
-		}
-	}
-
-	// Find first note which begins at or after t
-	_note_iter = seq.note_lower_bound(t);
-
-	// Find first sysex event at or after t
-	for (typename Sequence<Time>::SysExes::const_iterator i = seq.sysexes().begin();
-	     i != seq.sysexes().end(); ++i) {
-		if ((*i)->time() >= t) {
-			_sysex_iter = i;
-			break;
-		}
-	}
-	assert(_sysex_iter == seq.sysexes().end() || (*_sysex_iter)->time() >= t);
-
-	// Find first patch event at or after t
-	for (typename Sequence<Time>::PatchChanges::const_iterator i = seq.patch_changes().begin(); i != seq.patch_changes().end(); ++i) {
-		if ((*i)->time() >= t) {
-			_patch_change_iter = i;
-			break;
-		}
-	}
-	assert (_patch_change_iter == seq.patch_changes().end() || (*_patch_change_iter)->time() >= t);
-
-	// Find first control event after t
-	_control_iters.reserve(seq._controls.size());
-	bool   found                  = false;
-	size_t earliest_control_index = 0;
-	double earliest_control_x     = DBL_MAX;
-	for (Controls::const_iterator i = seq._controls.begin(); i != seq._controls.end(); ++i) {
-
-		if (filtered.find (i->first) != filtered.end()) {
-			/* this parameter is filtered, so don't bother setting up an iterator for it */
-			continue;
-		}
-
-		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 || i->second->list()->interpolation() == ControlList::Discrete) {
-			ret = i->second->list()->rt_safe_earliest_event_discrete_unlocked (t.to_double(), x, y, true);
-		} else {
-			ret = i->second->list()->rt_safe_earliest_event_unlocked(t.to_double(), x, y, true);
-		}
-		if (!ret) {
-			DEBUG_TRACE (DEBUG::Sequence, string_compose ("Iterator: CC %1 (size %2) has no events past %3\n",
-			                                              i->first.id(), i->second->list()->size(), t));
-			continue;
-		}
-
-		assert(x >= 0);
-
-		const ParameterDescriptor& desc = seq.type_map().descriptor(i->first);
-		if (y < desc.lower || y > desc.upper) {
-			cerr << "ERROR: Controller value " << y
-			     << " out of range [" << desc.lower << "," << desc.upper
-			     << "], event ignored" << endl;
-			continue;
-		}
-
-		DEBUG_TRACE (DEBUG::Sequence, string_compose ("Iterator: CC %1 added (%2, %3)\n", i->first.id(), x, y));
-
-		const ControlIterator new_iter(i->second->list(), x, y);
-		_control_iters.push_back(new_iter);
-
-		// Found a new earliest_control
-		if (x < earliest_control_x) {
-			earliest_control_x     = x;
-			earliest_control_index = _control_iters.size() - 1;
-			found                  = true;
-		}
-	}
-
-	if (found) {
-		_control_iter = _control_iters.begin() + earliest_control_index;
-		assert(_control_iter != _control_iters.end());
-		assert(_control_iter->list);
-	} else {
-		_control_iter = _control_iters.end();
-	}
-
-	// Choose the earliest event overall to point to
-	choose_next(t);
-
-	// Allocate a new event for storing the current event in MIDI format
-	_event = boost::shared_ptr< Event<Time> >(
-		new Event<Time>(0, Time(), 4, NULL, true));
-
-	// Set event from chosen sub-iterator
-	set_event();
-
-	if (_is_end) {
-		DEBUG_TRACE(DEBUG::Sequence,
-		            string_compose("Starting at end @ %1\n", t));
-	} else {
-		DEBUG_TRACE(DEBUG::Sequence,
-		            string_compose("Starting at type 0x%1 : 0x%2 @ %3\n",
-		                           (int)_event->event_type(),
-		                           (int)((MIDIEvent<Time>*)_event.get())->type(),
-		                           _event->time()));
-	}
-}
-
-template<typename Time>
-void
-Sequence<Time>::const_iterator::invalidate(std::set< boost::weak_ptr< Note<Time> > >* notes)
-{
-	while (!_active_notes.empty()) {
-		if (notes) {
-			notes->insert(_active_notes.top());
-		}
-		_active_notes.pop();
-	}
-	_type = NIL;
-	_is_end = true;
-	if (_seq) {
-		_note_iter = _seq->notes().end();
-		_sysex_iter = _seq->sysexes().end();
-		_patch_change_iter = _seq->patch_changes().end();
-		_active_patch_change_message = 0;
-	}
-	_control_iters.clear();
-	_control_iter = _control_iters.end();
-	_lock.reset();
-}
-
-template<typename Time>
-Time
-Sequence<Time>::const_iterator::choose_next(Time earliest_t)
-{
-	_type = NIL;
-
-	// Next earliest note on
-	if (_note_iter != _seq->notes().end()) {
-		_type      = NOTE_ON;
-		earliest_t = (*_note_iter)->time();
-	}
-
-	// Use the next note off iff it's earlier or the same time as the note on
-	if ((!_active_notes.empty())) {
-		if (_type == NIL || _active_notes.top()->end_time().to_double() <= earliest_t.to_double()) {
-			_type      = NOTE_OFF;
-			earliest_t = _active_notes.top()->end_time();
-		}
-	}
-
-	// Use the next earliest controller iff it's earlier than the note event
-	if (_control_iter != _control_iters.end() &&
-	    _control_iter->list && _control_iter->x != DBL_MAX) {
-		if (_type == NIL || _control_iter->x < earliest_t.to_double()) {
-			_type      = CONTROL;
-			earliest_t = Time(_control_iter->x);
-		}
-	}
-
-	// Use the next earliest SysEx iff it's earlier than the controller
-	if (_sysex_iter != _seq->sysexes().end()) {
-		if (_type == NIL || (*_sysex_iter)->time() < earliest_t) {
-			_type      = SYSEX;
-			earliest_t = (*_sysex_iter)->time();
-		}
-	}
-
-	// Use the next earliest patch change iff it's earlier than the SysEx
-	if (_patch_change_iter != _seq->patch_changes().end()) {
-		if (_type == NIL || (*_patch_change_iter)->time() < earliest_t) {
-			_type      = PATCH_CHANGE;
-			earliest_t = (*_patch_change_iter)->time();
-		}
-	}
-	return earliest_t;
-}
-
-template<typename Time>
-void
-Sequence<Time>::const_iterator::set_event()
-{
-	switch (_type) {
-	case NOTE_ON:
-		DEBUG_TRACE(DEBUG::Sequence, "iterator = note on\n");
-		_event->assign ((*_note_iter)->on_event());
-		_active_notes.push(*_note_iter);
-		break;
-	case NOTE_OFF:
-		DEBUG_TRACE(DEBUG::Sequence, "iterator = note off\n");
-		assert(!_active_notes.empty());
-		_event->assign (_active_notes.top()->off_event());
-		// We don't pop the active note until we increment past it
-		break;
-	case SYSEX:
-		DEBUG_TRACE(DEBUG::Sequence, "iterator = sysex\n");
-		_event->assign (*(*_sysex_iter));
-		break;
-	case CONTROL:
-		DEBUG_TRACE(DEBUG::Sequence, "iterator = control\n");
-		_seq->control_to_midi_event(_event, *_control_iter);
-		break;
-	case PATCH_CHANGE:
-		DEBUG_TRACE(DEBUG::Sequence, "iterator = program change\n");
-		_event->assign ((*_patch_change_iter)->message (_active_patch_change_message));
-		break;
-	default:
-		_is_end = true;
-		break;
-	}
-
-	if (_type == NIL || !_event || _event->size() == 0) {
-		DEBUG_TRACE(DEBUG::Sequence, "iterator = end\n");
-		_type   = NIL;
-		_is_end = true;
-	} else {
-		assert(midi_event_is_valid(_event->buffer(), _event->size()));
-	}
-}
-
-template<typename Time>
-const typename Sequence<Time>::const_iterator&
-Sequence<Time>::const_iterator::operator++()
-{
-	if (_is_end) {
-		throw std::logic_error("Attempt to iterate past end of Sequence");
-	}
-
-	assert(_event && _event->buffer() && _event->size() > 0);
-
-	const MIDIEvent<Time>& ev = *((MIDIEvent<Time>*)_event.get());
-
-	if (!(     ev.is_note()
-	           || ev.is_cc()
-	           || ev.is_pgm_change()
-	           || ev.is_pitch_bender()
-	           || ev.is_channel_pressure()
-	           || ev.is_sysex()) ) {
-		cerr << "WARNING: Unknown event (type " << _type << "): " << hex
-		     << int(ev.buffer()[0]) << int(ev.buffer()[1]) << int(ev.buffer()[2]) << endl;
-	}
-
-	double x   = 0.0;
-	double y   = 0.0;
-	bool   ret = false;
-
-	// Increment past current event
-	switch (_type) {
-	case NOTE_ON:
-		++_note_iter;
-		break;
-	case NOTE_OFF:
-		_active_notes.pop();
-		break;
-	case CONTROL:
-		// 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);
-		} else {
-			ret = _control_iter->list->rt_safe_earliest_event_linear_unlocked (
-				_control_iter->x + time_between_interpolated_controller_outputs, x, y, false);
-		}
-		assert(!ret || x > _control_iter->x);
-		if (ret) {
-			_control_iter->x = x;
-			_control_iter->y = y;
-		} else {
-			_control_iter->list.reset();
-			_control_iter->x = DBL_MAX;
-			_control_iter->y = DBL_MAX;
-		}
-
-		// Find the controller with the next earliest event time
-		_control_iter = _control_iters.begin();
-		for (ControlIterators::iterator i = _control_iters.begin();
-		     i != _control_iters.end(); ++i) {
-			if (i->x < _control_iter->x) {
-				_control_iter = i;
-			}
-		}
-		break;
-	case SYSEX:
-		++_sysex_iter;
-		break;
-	case PATCH_CHANGE:
-		++_active_patch_change_message;
-		if (_active_patch_change_message == (*_patch_change_iter)->messages()) {
-			++_patch_change_iter;
-			_active_patch_change_message = 0;
-		}
-		break;
-	default:
-		assert(false);
-	}
-
-	// Choose the earliest event overall to point to
-	choose_next(std::numeric_limits<Time>::max());
-
-	// Set event from chosen sub-iterator
-	set_event();
-
-	assert(_is_end || (_event->size() > 0 && _event->buffer() && _event->buffer()[0] != '\0'));
-
-	return *this;
-}
-
-template<typename Time>
-bool
-Sequence<Time>::const_iterator::operator==(const const_iterator& other) const
-{
-	if (_seq != other._seq) {
-		return false;
-	} else if (_is_end || other._is_end) {
-		return (_is_end == other._is_end);
-	} else if (_type != other._type) {
-		return false;
-	} else {
-		return (_event == other._event);
-	}
-}
-
-template<typename Time>
-typename Sequence<Time>::const_iterator&
-Sequence<Time>::const_iterator::operator=(const const_iterator& other)
-{
-	_seq           = other._seq;
-	_event         = other._event;
-	_active_notes  = other._active_notes;
-	_type          = other._type;
-	_is_end        = other._is_end;
-	_note_iter     = other._note_iter;
-	_sysex_iter    = other._sysex_iter;
-	_patch_change_iter = other._patch_change_iter;
-	_control_iters = other._control_iters;
-	_force_discrete = other._force_discrete;
-	_active_patch_change_message = other._active_patch_change_message;
-
-	if (other._lock) {
-		_lock = _seq->read_lock();
-	} else {
-		_lock.reset();
-	}
-
-	if (other._control_iter == other._control_iters.end()) {
-		_control_iter = _control_iters.end();
-	} else {
-		const size_t index = other._control_iter - other._control_iters.begin();
-		_control_iter  = _control_iters.begin() + index;
-	}
-
-	return *this;
-}
-
 // Sequence
 
 template<typename Time>
@@ -463,14 +66,11 @@ Sequence<Time>::Sequence(const TypeMap& type_map)
 	, _overlap_pitch_resolution (FirstOnFirstOff)
 	, _writing(false)
 	, _type_map(type_map)
-	, _end_iter(*this, std::numeric_limits<Time>::max(), false, std::set<Evoral::Parameter> ())
 	, _percussive(false)
 	, _lowest_note(127)
 	, _highest_note(0)
 {
 	DEBUG_TRACE (DEBUG::Sequence, string_compose ("Sequence constructed: %1\n", this));
-	assert(_end_iter._is_end);
-	assert( ! _end_iter._lock);
 
 	for (int i = 0; i < 16; ++i) {
 		_bank[i] = 0;
@@ -485,7 +85,6 @@ Sequence<Time>::Sequence(const Sequence<Time>& other)
 	, _overlap_pitch_resolution (other._overlap_pitch_resolution)
 	, _writing(false)
 	, _type_map(other._type_map)
-	, _end_iter(*this, std::numeric_limits<Time>::max(), false, std::set<Evoral::Parameter> ())
 	, _percussive(other._percussive)
 	, _lowest_note(other._lowest_note)
 	, _highest_note(other._highest_note)
@@ -510,8 +109,6 @@ Sequence<Time>::Sequence(const Sequence<Time>& other)
 	}
 
 	DEBUG_TRACE (DEBUG::Sequence, string_compose ("Sequence copied: %1\n", this));
-	assert(_end_iter._is_end);
-	assert(! _end_iter._lock);
 }
 
 /** Write the controller event pointed to by \a iter to \a ev.
@@ -1387,7 +984,7 @@ Sequence<Time>::dump (ostream& str) const
 {
 	typename Sequence<Time>::const_iterator i;
 	str << "+++ dump\n";
-	for (i = begin(); i != end(); ++i) {
+	for (i = begin (); i != end(); ++i) {
 		str << *i << endl;
 	}
 	str << "--- dump\n";