split up session code that uses parts of the JACK API (timebase + session event handling) and connect it directly to the jack audiobackend

i've made the audiobackend call the session directly so that only one object (ARDOUR::Session) has a need for the JACK types
and only one .cc file (session_jack.cc) needs jack.h. having ARDOUR::AudioEngine act as an intermediary would be cleaner
conceptually but would end up causing two different ARDOUR objects to have jack types in their own API.

8 files changed, 213 insertions, 199 deletions

diff --git a/libs/ardour/ardour/audioengine.h b/libs/ardour/ardour/audioengine.h
index 509d330f12..f05944797d 100644
--- a/libs/ardour/ardour/audioengine.h
+++ b/libs/ardour/ardour/audioengine.h
@@ -129,7 +129,8 @@ public:
     
     void set_session (Session *);
     void remove_session (); // not a replacement for SessionHandle::session_going_away()
-    
+    Session* session() const { return _session; }
+
     class NoBackendAvailable : public std::exception {
       public:
 	virtual const char *what() const throw() { return "could not connect to engine backend"; }
@@ -148,12 +149,7 @@ public:
     PBD::Signal1<int, pframes_t> Freewheel;
     
     PBD::Signal0<void> Xrun;
-    
 
-#ifdef HAVE_JACK_SESSION
-    PBD::Signal1<void,jack_session_event_t *> JackSessionEvent;
-#endif
-    
     /* this signal is emitted if the sample rate changes */
     
     PBD::Signal1<void, framecnt_t> SampleRateChanged;
diff --git a/libs/ardour/ardour/session.h b/libs/ardour/ardour/session.h
index c291220874..31f0658931 100644
--- a/libs/ardour/ardour/session.h
+++ b/libs/ardour/ardour/session.h
@@ -381,9 +381,6 @@ class Session : public PBD::StatefulDestructible, public PBD::ScopedConnectionLi
 	framecnt_t worst_track_latency ()  const { return _worst_track_latency; }
 	framecnt_t worst_playback_latency () const { return _worst_output_latency + _worst_track_latency; }
 
-#ifdef HAVE_JACK_SESSION
-	void jack_session_event (jack_session_event_t* event);
-#endif
 	int save_state (std::string snapshot_name, bool pending = false, bool switch_to_snapshot = false);
 	int restore_state (std::string snapshot_name);
 	int save_template (std::string template_name);
@@ -863,6 +860,15 @@ class Session : public PBD::StatefulDestructible, public PBD::ScopedConnectionLi
 	boost::shared_ptr<IO> ltc_input_io() { return _ltc_input; }
 	boost::shared_ptr<IO> ltc_output_io() { return _ltc_output; }
 
+        /* Callbacks specifically related to JACK, and called directly
+	 * from the JACK audio backend.
+         */
+
+#ifdef HAVE_JACK_SESSION
+	void jack_session_event (jack_session_event_t* event);
+#endif
+        void jack_timebase_callback (jack_transport_state_t, pframes_t, jack_position_t*, int);
+
   protected:
 	friend class AudioEngine;
 	void set_block_size (pframes_t nframes);
@@ -1436,9 +1442,8 @@ class Session : public PBD::StatefulDestructible, public PBD::ScopedConnectionLi
 	 */
 	std::list<GQuark> _current_trans_quarks;
 
-        // void timebase_callback (TransportState, pframes_t, jack_position_t*, int);
-        int  jack_sync_callback (TransportState, framepos_t);
-	void reset_jack_connection (jack_client_t* jack);
+        int  backend_sync_callback (TransportState, framepos_t);
+
 	void process_rtop (SessionEvent*);
 
 	void  update_latency (bool playback);
diff --git a/libs/ardour/audioengine.cc b/libs/ardour/audioengine.cc
index 45cc33cdc1..2b9a50f1ef 100644
--- a/libs/ardour/audioengine.cc
+++ b/libs/ardour/audioengine.cc
@@ -891,21 +891,11 @@ AudioEngine::thread_init_callback (void* arg)
 	}
 }
 
-/* XXXX
-void
-AudioEngine::timebase_callback (TransportState state, pframes_t nframes, jack_position_t pos, int new_position)
-{
-	if (_session && _session->synced_to_jack()) {
-		// _session->timebase_callback (state, nframes, pos, new_position);
-	}
-}
-*/
-
 int
 AudioEngine::sync_callback (TransportState state, framepos_t position)
 {
 	if (_session) {
-		return _session->jack_sync_callback (state, position);
+		return _session->backend_sync_callback (state, position);
 	}
 	return 0;
 }
diff --git a/libs/ardour/jack_audiobackend.cc b/libs/ardour/jack_audiobackend.cc
index a3bbaecb2d..ece8c4788e 100644
--- a/libs/ardour/jack_audiobackend.cc
+++ b/libs/ardour/jack_audiobackend.cc
@@ -28,7 +28,9 @@
 #include "jack/thread.h"
 
 #include "ardour/audioengine.h"
+#include "ardour/session.h"
 #include "ardour/types.h"
+
 #include "ardour/jack_audiobackend.h"
 #include "ardour/jack_connection.h"
 #include "ardour/jack_portengine.h"
@@ -680,32 +682,14 @@ JACKAudioBackend::_jack_timebase_callback (jack_transport_state_t state, pframes
 }
 
 void
-JACKAudioBackend::jack_timebase_callback (jack_transport_state_t state, pframes_t /*nframes*/,
-					  jack_position_t* pos, int /*new_position*/)
+JACKAudioBackend::jack_timebase_callback (jack_transport_state_t state, pframes_t nframes,
+					  jack_position_t* pos, int new_position)
 {
-	TransportState tstate;
-	framepos_t position;
-
-	switch (state) {
-	case JackTransportStopped:
-		tstate = TransportStopped;
-		break;
-	case JackTransportRolling:
-		tstate = TransportRolling;
-		break;
-	case JackTransportLooping:
-		tstate = TransportLooping;
-		break;
-	case JackTransportStarting:
-		tstate = TransportStarting;
-		break;
-	}
+	ARDOUR::Session* session = engine.session();
 
-	if (pos) {
-		position = pos->frame;
+	if (session) {
+		session->jack_timebase_callback (state, nframes, pos, new_position);
 	}
-
-	// engine.timebase_callback (tstate, nframes, position, new_position);
 }
 
 int
@@ -754,8 +738,10 @@ void
 JACKAudioBackend::_session_callback (jack_session_event_t *event, void *arg)
 {
 	JACKAudioBackend* ae = static_cast<JACKAudioBackend*> (arg);
-	if (ae->connected()) {
-		ae->engine.JackSessionEvent (event); /* EMIT SIGNAL */
+	ARDOUR::Session* session = ae->engine.session();
+
+	if (session) {
+		session->jack_session_event (event);
 	}
 }
 #endif
diff --git a/libs/ardour/session_jack.cc b/libs/ardour/session_jack.cc
new file mode 100644
index 0000000000..af8a93fec3
--- /dev/null
+++ b/libs/ardour/session_jack.cc
@@ -0,0 +1,185 @@
+/*
+  Copyright (C) 1999-2013 Paul Davis
+
+  This program is free software; you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation; either version 2 of the License, or
+  (at your option) any later version.
+
+  This program is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program; if not, write to the Free Software
+  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+*/
+
+
+#ifdef WAF_BUILD
+#include "libardour-config.h"
+#endif
+
+#include <time.h>
+
+#include <glibmm/miscutils.h>
+
+#include "jack/jack.h"
+#include "jack/session.h"
+
+#include "ardour/audioengine.h"
+#include "ardour/filename_extensions.h"
+#include "ardour/session.h"
+#include "ardour/session_directory.h"
+#include "ardour/tempo.h"
+
+using namespace ARDOUR;
+using std::string;
+
+#ifdef HAVE_JACK_SESSION
+void
+Session::jack_session_event (jack_session_event_t* event)
+{
+        char timebuf[128], *tmp;
+        time_t n;
+        struct tm local_time;
+
+        time (&n);
+        localtime_r (&n, &local_time);
+        strftime (timebuf, sizeof(timebuf), "JS_%FT%T", &local_time);
+
+        while ((tmp = strchr(timebuf, ':'))) { *tmp = '.'; }
+
+        if (event->type == JackSessionSaveTemplate)
+        {
+                if (save_template( timebuf )) {
+                        event->flags = JackSessionSaveError;
+                } else {
+                        string cmd ("ardour3 -P -U ");
+                        cmd += event->client_uuid;
+                        cmd += " -T ";
+                        cmd += timebuf;
+
+                        event->command_line = strdup (cmd.c_str());
+                }
+        }
+        else
+        {
+                if (save_state (timebuf)) {
+                        event->flags = JackSessionSaveError;
+                } else {
+			std::string xml_path (_session_dir->root_path());
+			std::string legalized_filename = legalize_for_path (timebuf) + statefile_suffix;
+			xml_path = Glib::build_filename (xml_path, legalized_filename);
+
+                        string cmd ("ardour3 -P -U ");
+                        cmd += event->client_uuid;
+                        cmd += " \"";
+                        cmd += xml_path;
+                        cmd += '\"';
+
+                        event->command_line = strdup (cmd.c_str());
+                }
+        }
+
+	/* this won't be called if the port engine in use is not JACK, so we do 
+	   not have to worry about the type of PortEngine::private_handle()
+	*/
+
+	jack_client_t* jack_client = (jack_client_t*) AudioEngine::instance()->port_engine().private_handle();
+	
+	if (jack_client) {
+		jack_session_reply (jack_client, event);
+	}
+
+	if (event->type == JackSessionSaveAndQuit) {
+		Quit (); /* EMIT SIGNAL */
+	}
+
+	jack_session_event_free( event );
+}
+#endif
+
+void
+Session::jack_timebase_callback (jack_transport_state_t /*state*/,
+				 pframes_t /*nframes*/,
+				 jack_position_t* pos,
+				 int /*new_position*/)
+{
+	Timecode::BBT_Time bbt;
+
+	/* BBT info */
+
+	if (_tempo_map) {
+
+		TempoMetric metric (_tempo_map->metric_at (_transport_frame));
+
+		try {
+			_tempo_map->bbt_time_rt (_transport_frame, bbt);
+
+			pos->bar = bbt.bars;
+			pos->beat = bbt.beats;
+			pos->tick = bbt.ticks;
+			
+			// XXX still need to set bar_start_tick
+			
+			pos->beats_per_bar = metric.meter().divisions_per_bar();
+			pos->beat_type = metric.meter().note_divisor();
+			pos->ticks_per_beat = Timecode::BBT_Time::ticks_per_beat;
+			pos->beats_per_minute = metric.tempo().beats_per_minute();
+			
+			pos->valid = jack_position_bits_t (pos->valid | JackPositionBBT);
+
+		} catch (...) {
+			/* no message */
+		}
+	}
+
+#ifdef HAVE_JACK_VIDEO_SUPPORT
+	//poke audio video ratio so Ardour can track Video Sync
+	pos->audio_frames_per_video_frame = frame_rate() / timecode_frames_per_second();
+	pos->valid = jack_position_bits_t (pos->valid | JackAudioVideoRatio);
+#endif
+
+#if 0
+	/* Timecode info */
+
+	pos->timecode_offset = config.get_timecode_offset();
+	t.timecode_frame_rate = timecode_frames_per_second();
+	pos->valid = jack_position_bits_t (pos->valid | JackPositionTimecode;
+
+	if (_transport_speed) {
+
+		if (play_loop) {
+
+			Location* location = _locations.auto_loop_location();
+
+			if (location) {
+
+				t.transport_state = JackTransportLooping;
+				t.loop_start = location->start();
+				t.loop_end = location->end();
+				t.valid = jack_transport_bits_t (t.valid | JackTransportLoop);
+
+			} else {
+
+				t.loop_start = 0;
+				t.loop_end = 0;
+				t.transport_state = JackTransportRolling;
+
+			}
+
+		} else {
+
+			t.loop_start = 0;
+			t.loop_end = 0;
+			t.transport_state = JackTransportRolling;
+
+		}
+
+	}
+#endif
+}
+
diff --git a/libs/ardour/session_state.cc b/libs/ardour/session_state.cc
index c4522f76e7..50905ef434 100644
--- a/libs/ardour/session_state.cc
+++ b/libs/ardour/session_state.cc
@@ -1,5 +1,5 @@
 /*
-  Copyright (C) 1999-2002 Paul Davis
+  Copyright (C) 1999-2013 Paul Davis
 
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -689,70 +689,6 @@ Session::remove_state (string snapshot_name)
 	}
 }
 
-#ifdef HAVE_JACK_SESSION
-void
-Session::jack_session_event (jack_session_event_t * event)
-{
-        char timebuf[128], *tmp;
-        time_t n;
-        struct tm local_time;
-
-        time (&n);
-        localtime_r (&n, &local_time);
-        strftime (timebuf, sizeof(timebuf), "JS_%FT%T", &local_time);
-
-        while ((tmp = strchr(timebuf, ':'))) { *tmp = '.'; }
-
-        if (event->type == JackSessionSaveTemplate)
-        {
-                if (save_template( timebuf )) {
-                        event->flags = JackSessionSaveError;
-                } else {
-                        string cmd ("ardour3 -P -U ");
-                        cmd += event->client_uuid;
-                        cmd += " -T ";
-                        cmd += timebuf;
-
-                        event->command_line = strdup (cmd.c_str());
-                }
-        }
-        else
-        {
-                if (save_state (timebuf)) {
-                        event->flags = JackSessionSaveError;
-                } else {
-			std::string xml_path (_session_dir->root_path());
-			std::string legalized_filename = legalize_for_path (timebuf) + statefile_suffix;
-			xml_path = Glib::build_filename (xml_path, legalized_filename);
-
-                        string cmd ("ardour3 -P -U ");
-                        cmd += event->client_uuid;
-                        cmd += " \"";
-                        cmd += xml_path;
-                        cmd += '\"';
-
-                        event->command_line = strdup (cmd.c_str());
-                }
-        }
-
-	/* this won't be called if the port engine in use is not JACK, so we do 
-	   not have to worry about the type of PortEngine::private_handle()
-	*/
-
-	jack_client_t* jack_client = (jack_client_t*) AudioEngine::instance()->port_engine().private_handle();
-	
-	if (jack_client) {
-		jack_session_reply (jack_client, event);
-	}
-
-	if (event->type == JackSessionSaveAndQuit) {
-		Quit (); /* EMIT SIGNAL */
-	}
-
-	jack_session_event_free( event );
-}
-#endif
-
 /** @param snapshot_name Name to save under, without .ardour / .pending prefix */
 int
 Session::save_state (string snapshot_name, bool pending, bool switch_to_snapshot)
diff --git a/libs/ardour/session_time.cc b/libs/ardour/session_time.cc
index 088712f625..0f2186c09b 100644
--- a/libs/ardour/session_time.cc
+++ b/libs/ardour/session_time.cc
@@ -180,7 +180,7 @@ Session::timecode_time (Timecode::Time &t)
 }
 
 int
-Session::jack_sync_callback (TransportState state, framepos_t pos)
+Session::backend_sync_callback (TransportState state, framepos_t pos)
 {
 	bool slave = synced_to_jack();
 
@@ -218,91 +218,6 @@ Session::jack_sync_callback (TransportState state, framepos_t pos)
 	return true;
 }
 
-/* XXX REQUIRES SOMEWAY TO EFFICIENTLY ACCESS jack_position_t WITHOUT BRIDGING
- * THE ENTIRE DATA STRUCTURE
- */
-#if 0 
-void
-Session::jack_timebase_callback (TransportState /*state*/,
-				 pframes_t /*nframes*/,
-				 framepos_t pos,
-				 int /*new_position*/)
-{
-	Timecode::BBT_Time bbt;
-
-	/* BBT info */
-
-	if (_tempo_map) {
-
-		TempoMetric metric (_tempo_map->metric_at (_transport_frame));
-
-		try {
-			_tempo_map->bbt_time_rt (_transport_frame, bbt);
-
-			pos->bar = bbt.bars;
-			pos->beat = bbt.beats;
-			pos->tick = bbt.ticks;
-			
-			// XXX still need to set bar_start_tick
-			
-			pos->beats_per_bar = metric.meter().divisions_per_bar();
-			pos->beat_type = metric.meter().note_divisor();
-			pos->ticks_per_beat = Timecode::BBT_Time::ticks_per_beat;
-			pos->beats_per_minute = metric.tempo().beats_per_minute();
-			
-			pos->valid = jack_position_bits_t (pos->valid | JackPositionBBT);
-
-		} catch (...) {
-			/* no message */
-		}
-	}
-
-#ifdef HAVE_JACK_VIDEO_SUPPORT
-	//poke audio video ratio so Ardour can track Video Sync
-	pos->audio_frames_per_video_frame = frame_rate() / timecode_frames_per_second();
-	pos->valid = jack_position_bits_t (pos->valid | JackAudioVideoRatio);
-#endif
-
-#if 0
-	/* Timecode info */
-
-	pos->timecode_offset = config.get_timecode_offset();
-	t.timecode_frame_rate = timecode_frames_per_second();
-	pos->valid = jack_position_bits_t (pos->valid | JackPositionTimecode;
-
-	if (_transport_speed) {
-
-		if (play_loop) {
-
-			Location* location = _locations.auto_loop_location();
-
-			if (location) {
-
-				t.transport_state = JackTransportLooping;
-				t.loop_start = location->start();
-				t.loop_end = location->end();
-				t.valid = jack_transport_bits_t (t.valid | JackTransportLoop);
-
-			} else {
-
-				t.loop_start = 0;
-				t.loop_end = 0;
-				t.transport_state = JackTransportRolling;
-
-			}
-
-		} else {
-
-			t.loop_start = 0;
-			t.loop_end = 0;
-			t.transport_state = JackTransportRolling;
-
-		}
-
-	}
-#endif
-}
-#endif /* jack data structure issues */
 
 ARDOUR::framecnt_t
 Session::convert_to_frames (AnyTime const & position)
diff --git a/libs/ardour/wscript b/libs/ardour/wscript
index c140c6eb3a..57b68a0fde 100644
--- a/libs/ardour/wscript
+++ b/libs/ardour/wscript
@@ -180,6 +180,7 @@ libardour_sources = [
         'session_events.cc',
         'session_export.cc',
         'session_handle.cc',
+        'session_jack.cc',
         'session_ltc.cc',
         'session_metadata.cc',
         'session_midi.cc',