Handle edits while playing precisely.

This avoids stuck notes if active notes are edited, but without stopping all
active notes in the region on any edit as before.

This implementation injects note ons in places that aren't actually note
starts.  Depending on how percussive the instrument is, this may not be
desired.  In the future, an option for this would be an improvement, but there
are other places where "start notes in the middle" is a reasonable option.  I
think that should be handled universally if we're to do it at all, so not
considering it a part of this fix for now.

1 files changed, 11 insertions, 17 deletions

diff --git a/libs/ardour/midi_model.cc b/libs/ardour/midi_model.cc
index 7e88569adc..de5000669c 100644
--- a/libs/ardour/midi_model.cc
+++ b/libs/ardour/midi_model.cc
@@ -1612,25 +1612,19 @@ MidiModel::find_sysex (gint sysex_id)
 MidiModel::WriteLock
 MidiModel::edit_lock()
 {
-	boost::shared_ptr<MidiSource> ms = _midi_source.lock ();
-	assert (ms);
-
-	Glib::Threads::Mutex::Lock* source_lock = new Glib::Threads::Mutex::Lock (ms->mutex());
-	ms->invalidate(*source_lock); // Release cached iterator's read lock on model
-	return WriteLock(new WriteLockImpl(source_lock, _lock, _control_lock));
-}
+	boost::shared_ptr<MidiSource> ms          = _midi_source.lock();
+	Glib::Threads::Mutex::Lock*   source_lock = 0;
 
-/** Lock just the model, the source lock must already be held.
- * This should only be called from libardour/evoral places
- */
-MidiModel::WriteLock
-MidiModel::write_lock()
-{
-	boost::shared_ptr<MidiSource> ms = _midi_source.lock ();
-	assert (ms);
+	if (ms) {
+		/* Take source lock and invalidate iterator to release its lock on model.
+		   Add currently active notes to _active_notes so we can restore them
+		   if playback resumes at the same point after the edit. */
+		source_lock = new Glib::Threads::Mutex::Lock(ms->mutex());
+		ms->invalidate(*source_lock,
+		               ms->session().transport_rolling() ? &_active_notes : NULL);
+	}
 
-	assert (!ms->mutex().trylock ());
-	return WriteLock(new WriteLockImpl(0, _lock, _control_lock));
+	return WriteLock(new WriteLockImpl(source_lock, _lock, _control_lock));
 }
 
 int