Remove non-RT-safe alloc in the MIDI process() call.

git-svn-id: svn://localhost/ardour2/branches/3.0@10441 d708f5d6-7413-0410-9779-e7cbd77b26cf

4 files changed, 49 insertions, 17 deletions

diff --git a/libs/ardour/ardour/midi_diskstream.h b/libs/ardour/ardour/midi_diskstream.h
index 6500871412..a7695b5ebf 100644
--- a/libs/ardour/ardour/midi_diskstream.h
+++ b/libs/ardour/ardour/midi_diskstream.h
@@ -110,10 +110,12 @@ class MidiDiskstream : public Diskstream
 	}
 
 	/** Emitted when some MIDI data has been received for recording.
-	 *  First parameter is the data.
-	 *  Second parameter is the source that it is destined for.
+	 *  Parameter is the source that it is destined for.
+	 *  A caller can get a copy of the data with get_gui_feed_buffer ()
 	 */
-	PBD::Signal2<void, boost::shared_ptr<MidiBuffer>, boost::weak_ptr<MidiSource> > DataRecorded;
+	PBD::Signal1<void, boost::weak_ptr<MidiSource> > DataRecorded;
+
+	boost::shared_ptr<MidiBuffer> get_gui_feed_buffer () const;
 
   protected:
 	friend class Session;
@@ -189,6 +191,12 @@ class MidiDiskstream : public Diskstream
 	NoteMode                     _note_mode;
 	volatile gint                _frames_written_to_ringbuffer;
 	volatile gint                _frames_read_from_ringbuffer;
+
+	/** A buffer that we use to put newly-arrived MIDI data in for
+	    the GUI to read (so that it can update itself).
+	*/
+	MidiBuffer                   _gui_feed_buffer;
+	mutable Glib::Mutex          _gui_feed_buffer_mutex;
 };
 
 }; /* namespace ARDOUR */
diff --git a/libs/ardour/ardour/midi_track.h b/libs/ardour/ardour/midi_track.h
index 3d1ef558dc..a70fc4604d 100644
--- a/libs/ardour/ardour/midi_track.h
+++ b/libs/ardour/ardour/midi_track.h
@@ -104,7 +104,8 @@ public:
 		return false;
 	}
 
-	PBD::Signal2<void, boost::shared_ptr<MidiBuffer>, boost::weak_ptr<MidiSource> > DataRecorded;
+	PBD::Signal1<void, boost::weak_ptr<MidiSource> > DataRecorded;
+	boost::shared_ptr<MidiBuffer> get_gui_feed_buffer () const;
 
 	void set_input_active (bool);
 	bool input_active () const;
@@ -138,7 +139,7 @@ protected:
 	int no_roll (pframes_t nframes, framepos_t start_frame, framepos_t end_frame, bool state_changing);
 	void push_midi_input_to_step_edit_ringbuffer (framecnt_t nframes);
 
-	void diskstream_data_recorded (boost::shared_ptr<MidiBuffer>, boost::weak_ptr<MidiSource>);
+	void diskstream_data_recorded (boost::weak_ptr<MidiSource>);
 	PBD::ScopedConnection _diskstream_data_recorded_connection;
 
 	void track_input_active (IOChange, void*);
diff --git a/libs/ardour/midi_diskstream.cc b/libs/ardour/midi_diskstream.cc
index 7ab8c46c30..81217b179a 100644
--- a/libs/ardour/midi_diskstream.cc
+++ b/libs/ardour/midi_diskstream.cc
@@ -77,6 +77,7 @@ MidiDiskstream::MidiDiskstream (Session &sess, const string &name, Diskstream::F
 	, _note_mode(Sustained)
 	, _frames_written_to_ringbuffer(0)
 	, _frames_read_from_ringbuffer(0)
+	, _gui_feed_buffer(AudioEngine::instance()->raw_buffer_size (DataType::MIDI))
 {
 	in_set_state = true;
 
@@ -96,6 +97,7 @@ MidiDiskstream::MidiDiskstream (Session& sess, const XMLNode& node)
 	, _note_mode(Sustained)
 	, _frames_written_to_ringbuffer(0)
 	, _frames_read_from_ringbuffer(0)
+	, _gui_feed_buffer(AudioEngine::instance()->raw_buffer_size (DataType::MIDI))
 {
 	in_set_state = true;
 
@@ -549,17 +551,23 @@ MidiDiskstream::process (framepos_t transport_frame, pframes_t nframes, framecnt
 		}
 
 		if (buf.size() != 0) {
-			/* XXX this needs fixing - realtime new() call for
-			   every time we get MIDI data in a process callback!
-			*/
-
-			/* Make a copy of this data and emit it for the GUI to see */
-			boost::shared_ptr<MidiBuffer> copy (new MidiBuffer (buf.capacity ()));
-			for (MidiBuffer::iterator i = buf.begin(); i != buf.end(); ++i) {
-				copy->push_back ((*i).time() + transport_frame, (*i).size(), (*i).buffer());
+			Glib::Mutex::Lock lm (_gui_feed_buffer_mutex, Glib::TRY_LOCK);
+
+			if (lm.locked ()) {
+				/* Copy this data into our GUI feed buffer and tell the GUI
+				   that it can read it if it likes.
+				*/
+				_gui_feed_buffer.clear ();
+				
+				for (MidiBuffer::iterator i = buf.begin(); i != buf.end(); ++i) {
+					/* This may fail if buf is larger than _gui_feed_buffer, but it's not really
+					   the end of the world if it does.
+					*/
+					_gui_feed_buffer.push_back ((*i).time() + transport_frame, (*i).size(), (*i).buffer());
+				}
 			}
 
-			DataRecorded (copy, _write_source); /* EMIT SIGNAL */
+			DataRecorded (_write_source); /* EMIT SIGNAL */
 		}
 
 	} else {
@@ -1450,3 +1458,12 @@ MidiDiskstream::set_name (string const & name)
 	return true;
 }
 
+boost::shared_ptr<MidiBuffer>
+MidiDiskstream::get_gui_feed_buffer () const
+{
+	boost::shared_ptr<MidiBuffer> b (new MidiBuffer (AudioEngine::instance()->raw_buffer_size (DataType::MIDI)));
+	
+	Glib::Mutex::Lock lm (_gui_feed_buffer_mutex);
+	b->copy (_gui_feed_buffer);
+	return b;
+}
diff --git a/libs/ardour/midi_track.cc b/libs/ardour/midi_track.cc
index 9114311ac9..3253485412 100644
--- a/libs/ardour/midi_track.cc
+++ b/libs/ardour/midi_track.cc
@@ -122,7 +122,7 @@ MidiTrack::set_diskstream (boost::shared_ptr<Diskstream> ds)
 	boost::shared_ptr<MidiDiskstream> mds = boost::dynamic_pointer_cast<MidiDiskstream> (ds);
 	mds->DataRecorded.connect_same_thread (
 		_diskstream_data_recorded_connection,
-		boost::bind (&MidiTrack::diskstream_data_recorded, this, _1, _2));
+		boost::bind (&MidiTrack::diskstream_data_recorded, this, _1));
 
 	DiskstreamChanged (); /* EMIT SIGNAL */
 }
@@ -654,9 +654,9 @@ MidiTrack::midi_playlist ()
 }
 
 void
-MidiTrack::diskstream_data_recorded (boost::shared_ptr<MidiBuffer> buf, boost::weak_ptr<MidiSource> src)
+MidiTrack::diskstream_data_recorded (boost::weak_ptr<MidiSource> src)
 {
-	DataRecorded (buf, src); /* EMIT SIGNAL */
+	DataRecorded (src); /* EMIT SIGNAL */
 }
 
 bool
@@ -717,3 +717,9 @@ MidiTrack::diskstream_factory (XMLNode const & node)
 {
 	return boost::shared_ptr<Diskstream> (new MidiDiskstream (_session, node));
 }
+
+boost::shared_ptr<MidiBuffer>
+MidiTrack::get_gui_feed_buffer () const
+{
+	return midi_diskstream()->get_gui_feed_buffer ();
+}