Merge branch 'master' into windows+cc

Conflicts (hopefully resolved):
	gtk2_ardour/ardour_ui.cc
	gtk2_ardour/ardour_ui.h
	gtk2_ardour/ardour_ui_options.cc

18 files changed, 201 insertions, 94 deletions

diff --git a/libs/ardour/ardour/audio_backend.h b/libs/ardour/ardour/audio_backend.h
index 9052acd530..0e39625e8c 100644
--- a/libs/ardour/ardour/audio_backend.h
+++ b/libs/ardour/ardour/audio_backend.h
@@ -399,13 +399,25 @@ class AudioBackend : public PortEngine {
      * stacksize. The thread will begin executing @param func, and will exit
      * when that function returns.
      */
-    virtual int create_process_thread (boost::function<void()> func, AudioBackendNativeThread*, size_t stacksize) = 0;
+    virtual int create_process_thread (boost::function<void()> func) = 0;
 
-    /** Wait for the thread specified by @param thread to exit.
+    /** Wait for all processing threads to exit.
      * 
      * Return zero on success, non-zero on failure.
      */
-    virtual int wait_for_process_thread_exit (AudioBackendNativeThread thread) = 0;
+    virtual int join_process_threads () = 0;
+
+    /** Return true if execution context is in a backend thread
+     */
+    virtual bool in_process_thread () = 0;
+
+    /** Return the minimum stack size of audio threads in bytes
+     */
+    static size_t thread_stack_size () { return 100000; }
+
+    /** Return number of processing threads
+     */
+    virtual uint32_t process_thread_count () = 0;
 
     virtual void update_latencies () = 0;
 
diff --git a/libs/ardour/ardour/audioengine.h b/libs/ardour/ardour/audioengine.h
index 201d960479..1bf4be3243 100644
--- a/libs/ardour/ardour/audioengine.h
+++ b/libs/ardour/ardour/audioengine.h
@@ -100,8 +100,12 @@ public:
     pframes_t      sample_time_at_cycle_start ();
     pframes_t      samples_since_cycle_start ();
     bool           get_sync_offset (pframes_t& offset) const;
-    int            create_process_thread (boost::function<void()> func, AudioBackendNativeThread*, size_t stacksize);
-    int            wait_for_process_thread_exit (AudioBackendNativeThread);
+
+    int            create_process_thread (boost::function<void()> func);
+    int            join_process_threads ();
+    bool           in_process_thread ();
+    uint32_t       process_thread_count ();
+
     bool           is_realtime() const;
     bool           connected() const;
 
diff --git a/libs/ardour/ardour/graph.h b/libs/ardour/ardour/graph.h
index 08af6fb721..763723c792 100644
--- a/libs/ardour/ardour/graph.h
+++ b/libs/ardour/ardour/graph.h
@@ -31,8 +31,6 @@
 #include <glib.h>
 #include <cassert>
 
-#include <pthread.h>
-
 #include "pbd/semutils.h"
 
 #include "ardour/types.h"
@@ -59,8 +57,6 @@ class Graph : public SessionHandleRef
 public:
 	Graph (Session & session);
 
-	uint32_t threads_in_use () const { return _thread_list.size(); }
-
 	void prep();
 	void trigger (GraphNode * n);
 	void rechain (boost::shared_ptr<RouteList>, GraphEdges const &);
@@ -93,7 +89,6 @@ protected:
 	virtual void session_going_away ();
 
 private:
-	std::list<AudioBackendNativeThread> _thread_list;
 	volatile bool        _quit_threads;
 
 	void reset_thread_list ();
diff --git a/libs/ardour/ardour/rc_configuration_vars.h b/libs/ardour/ardour/rc_configuration_vars.h
index 78be86eaea..7000dde3ca 100644
--- a/libs/ardour/ardour/rc_configuration_vars.h
+++ b/libs/ardour/ardour/rc_configuration_vars.h
@@ -51,7 +51,7 @@ CONFIG_VARIABLE (int, mtc_qf_speed_tolerance, "mtc-qf-speed-tolerance", 5)
 CONFIG_VARIABLE (bool, timecode_sync_frame_rate, "timecode-sync-frame-rate", true)
 CONFIG_VARIABLE (bool, timecode_source_is_synced, "timecode-source-is-synced", true)
 CONFIG_VARIABLE (bool, timecode_source_2997, "timecode-source-2997", false)
-CONFIG_VARIABLE (SyncSource, sync_source, "sync-source", JACK)
+CONFIG_VARIABLE (SyncSource, sync_source, "sync-source", Engine)
 CONFIG_VARIABLE (std::string, ltc_source_port, "ltc-source-port", "system:capture_1")
 CONFIG_VARIABLE (bool, send_ltc, "send-ltc", false)
 CONFIG_VARIABLE (bool, ltc_send_continuously, "ltc-send-continuously", true)
diff --git a/libs/ardour/ardour/session.h b/libs/ardour/ardour/session.h
index 3fa9fbcb28..d8004e8505 100644
--- a/libs/ardour/ardour/session.h
+++ b/libs/ardour/ardour/session.h
@@ -161,6 +161,8 @@ class Session : public PBD::StatefulDestructible, public PBD::ScopedConnectionLi
 
 	virtual ~Session ();
 
+        static int get_info_from_path (const std::string& xmlpath, float& sample_rate, SampleFormat& data_format);
+
 	std::string path() const { return _path; }
 	std::string name() const { return _name; }
 	std::string snap_name() const { return _current_snapshot_name; }
@@ -509,7 +511,7 @@ class Session : public PBD::StatefulDestructible, public PBD::ScopedConnectionLi
 	static PBD::Signal1<void, framepos_t> EndTimeChanged;
 
 	void   request_sync_source (Slave*);
-	bool   synced_to_jack() const { return config.get_external_sync() && Config->get_sync_source() == JACK; }
+	bool   synced_to_engine() const { return config.get_external_sync() && Config->get_sync_source() == Engine; }
 
 	double transport_speed() const { return _transport_speed; }
 	bool   transport_stopped() const { return _transport_speed == 0.0f; }
@@ -1617,7 +1619,10 @@ class Session : public PBD::StatefulDestructible, public PBD::ScopedConnectionLi
 
     void setup_ltc ();
     void setup_click ();
+    void setup_click_state (const XMLNode&);
     void setup_bundles ();
+
+    static int get_session_info_from_path (XMLTree& state_tree, const std::string& xmlpath);
 };
 
 } // namespace ARDOUR
diff --git a/libs/ardour/ardour/slave.h b/libs/ardour/ardour/slave.h
index c60acb1df7..a0b7b878e4 100644
--- a/libs/ardour/ardour/slave.h
+++ b/libs/ardour/ardour/slave.h
@@ -486,11 +486,11 @@ class MIDIClock_Slave : public Slave {
 	bool _starting;
 };
 
-class JACK_Slave : public Slave
+class Engine_Slave : public Slave
 {
   public:
-	JACK_Slave (AudioEngine&);
-	~JACK_Slave ();
+	Engine_Slave (AudioEngine&);
+	~Engine_Slave ();
 
 	bool speed_and_position (double& speed, framepos_t& pos);
 
diff --git a/libs/ardour/ardour/types.h b/libs/ardour/ardour/types.h
index f2319d7669..ee43d1f30f 100644
--- a/libs/ardour/ardour/types.h
+++ b/libs/ardour/ardour/types.h
@@ -489,7 +489,12 @@ namespace ARDOUR {
 	};
 
 	enum SyncSource {
-		JACK,
+		/* These are "synonyms". It is important for JACK to be first
+		   both here and in enums.cc, so that the string "JACK" is
+		   correctly recognized in older session and preference files.
+		*/
+		JACK = 0,
+		Engine = 0,
 		MTC,
 		MIDIClock,
 		LTC
@@ -610,16 +615,6 @@ namespace ARDOUR {
 	    uint32_t max; //< samples
 	};
 
-/* PLATFORM SPECIFIC #ifdef's here */
-
-	/** Define the native thread type used on the platform */
-	typedef pthread_t AudioBackendNativeThread;
-	static inline bool self_thread_equal (AudioBackendNativeThread thr) {
-		return pthread_equal (thr, pthread_self());
-	}
-
-/* PLATFORM SPECIFIC #endif's here */
-
 } // namespace ARDOUR
 
 
diff --git a/libs/ardour/audioengine.cc b/libs/ardour/audioengine.cc
index 05fc469c77..7cb4e17a5c 100644
--- a/libs/ardour/audioengine.cc
+++ b/libs/ardour/audioengine.cc
@@ -824,21 +824,39 @@ AudioEngine::get_sync_offset (pframes_t& offset) const
 }
 
 int
-AudioEngine::create_process_thread (boost::function<void()> func, AudioBackendNativeThread* thr, size_t stacksize)
+AudioEngine::create_process_thread (boost::function<void()> func)
 {
 	if (!_backend) {
 		return -1;
 	}
-	return _backend->create_process_thread (func, thr, stacksize);
+	return _backend->create_process_thread (func);
 }
 
 int
-AudioEngine::wait_for_process_thread_exit (AudioBackendNativeThread thr)
+AudioEngine::join_process_threads ()
+{
+	if (!_backend) {
+		return -1;
+	}
+	return _backend->join_process_threads ();
+}
+
+bool
+AudioEngine::in_process_thread ()
+{
+	if (!_backend) {
+		return false;
+	}
+	return _backend->in_process_thread ();
+}
+
+uint32_t
+AudioEngine::process_thread_count ()
 {
 	if (!_backend) {
 		return 0;
 	}
-	return _backend->wait_for_process_thread_exit (thr);
+	return _backend->process_thread_count ();
 }
 
 int
diff --git a/libs/ardour/jack_slave.cc b/libs/ardour/engine_slave.cc
index 4b2f3b1860..eb55c9ba54 100644
--- a/libs/ardour/jack_slave.cc
+++ b/libs/ardour/engine_slave.cc
@@ -26,7 +26,7 @@
 using namespace std;
 using namespace ARDOUR;
 
-JACK_Slave::JACK_Slave (AudioEngine& e)
+Engine_Slave::Engine_Slave (AudioEngine& e)
 	: engine (e)
 {
 	double x;
@@ -35,24 +35,24 @@ JACK_Slave::JACK_Slave (AudioEngine& e)
 	speed_and_position (x, p);
 }
 
-JACK_Slave::~JACK_Slave ()
+Engine_Slave::~Engine_Slave ()
 {
 }
 
 bool
-JACK_Slave::locked() const
+Engine_Slave::locked() const
 {
 	return true;
 }
 
 bool
-JACK_Slave::ok() const
+Engine_Slave::ok() const
 {
 	return true;
 }
 
 bool
-JACK_Slave::speed_and_position (double& sp, framepos_t& position)
+Engine_Slave::speed_and_position (double& sp, framepos_t& position)
 {
 	switch (engine.transport_state()) {
 	case TransportStopped:
diff --git a/libs/ardour/enums.cc b/libs/ardour/enums.cc
index bab0e8ed15..2a38cd2c8a 100644
--- a/libs/ardour/enums.cc
+++ b/libs/ardour/enums.cc
@@ -336,6 +336,7 @@ setup_enum_writer ()
 
 	REGISTER_ENUM (MTC);
 	REGISTER_ENUM (JACK);
+	REGISTER_ENUM (Engine);
 	REGISTER_ENUM (MIDIClock);
 	REGISTER_ENUM (LTC);
 	REGISTER (_SyncSource);
diff --git a/libs/ardour/globals.cc b/libs/ardour/globals.cc
index 0cda9ebdf4..b3bfbd2239 100644
--- a/libs/ardour/globals.cc
+++ b/libs/ardour/globals.cc
@@ -544,7 +544,11 @@ ARDOUR::get_available_sync_options ()
 {
 	vector<SyncSource> ret;
 
-	ret.push_back (JACK);
+	boost::shared_ptr<AudioBackend> backend = AudioEngine::instance()->current_backend();
+	if (backend && backend->name() == "JACK") {
+		ret.push_back (Engine);
+	}
+
 	ret.push_back (MTC);
 	ret.push_back (MIDIClock);
 	ret.push_back (LTC);
diff --git a/libs/ardour/graph.cc b/libs/ardour/graph.cc
index 69c4953272..f8a1d51e10 100644
--- a/libs/ardour/graph.cc
+++ b/libs/ardour/graph.cc
@@ -97,29 +97,24 @@ Graph::reset_thread_list ()
            number of threads.
         */
 
-        if (_thread_list.size() == num_threads) {
+        if (AudioEngine::instance()->process_thread_count() == num_threads) {
                 return;
         }
 
         Glib::Threads::Mutex::Lock lm (_session.engine().process_lock());
-	AudioBackendNativeThread a_thread;
 
-        if (!_thread_list.empty()) {
+        if (AudioEngine::instance()->process_thread_count() != 0) {
                 drop_threads ();
         }
 
-	if (AudioEngine::instance()->create_process_thread (boost::bind (&Graph::main_thread, this), &a_thread, 100000) != 0) {
+	if (AudioEngine::instance()->create_process_thread (boost::bind (&Graph::main_thread, this)) != 0) {
 		throw failed_constructor ();
 	}
 
-	_thread_list.push_back (a_thread);
-
         for (uint32_t i = 1; i < num_threads; ++i) {
-		if (AudioEngine::instance()->create_process_thread (boost::bind (&Graph::helper_thread, this), &a_thread, 100000) != 0) {
+		if (AudioEngine::instance()->create_process_thread (boost::bind (&Graph::helper_thread, this))) {
 			throw failed_constructor ();
 		}
-		
-		_thread_list.push_back (a_thread);
         }
 }
 
@@ -141,17 +136,15 @@ Graph::drop_threads ()
 {
         _quit_threads = true;
 
-        for (unsigned int i=0; i< _thread_list.size(); i++) {
+        uint32_t thread_count = AudioEngine::instance()->process_thread_count ();
+
+        for (unsigned int i=0; i < thread_count; i++) {
 		_execution_sem.signal ();
         }
 
         _callback_start_sem.signal ();
 
-        for (list<AudioBackendNativeThread>::iterator i = _thread_list.begin(); i != _thread_list.end(); ++i) {
-		AudioEngine::instance()->wait_for_process_thread_exit (*i);
-        }
-
-        _thread_list.clear ();
+	AudioEngine::instance()->join_process_threads ();
 
 	_execution_tokens = 0;
 
@@ -584,10 +577,5 @@ Graph::process_one_route (Route* route)
 bool
 Graph::in_process_thread () const
 {
-	for (list<AudioBackendNativeThread>::const_iterator i = _thread_list.begin (); i != _thread_list.end(); ++i) {
-		if (self_thread_equal (*i)) {
-			return true;
-		}
-	}
-	return false;
+	return AudioEngine::instance()->in_process_thread ();
 }
diff --git a/libs/ardour/session.cc b/libs/ardour/session.cc
index 2a081086d4..4b30543cb0 100644
--- a/libs/ardour/session.cc
+++ b/libs/ardour/session.cc
@@ -276,6 +276,21 @@ Session::Session (AudioEngine &eng,
 			throw failed_constructor ();
 		}
 
+		/* if a mix template was provided, then ::create() will
+		 * have copied it into the session and we need to load it
+		 * so that we have the state ready for ::set_state()
+		 * after the engine is started.
+		 *
+		 * Note that we do NOT try to get the sample rate from
+		 * the template at this time, though doing so would
+		 * be easy if we decided this was an appropriate part
+		 * of a template.
+		 */
+
+		if (!mix_template.empty() && load_state (_current_snapshot_name)) {
+			throw failed_constructor ();
+		}
+
 	} else {
 
 		if (load_state (_current_snapshot_name)) {
@@ -393,7 +408,7 @@ Session::immediately_post_engine ()
 
 	_engine.Running.connect_same_thread (*this, boost::bind (&Session::initialize_latencies, this));
 
-	if (synced_to_jack()) {
+	if (synced_to_engine()) {
 		_engine.transport_stop ();
 	}
 
@@ -577,14 +592,21 @@ Session::setup_ltc ()
 void
 Session::setup_click ()
 {
-	XMLNode* child = 0;
-
 	_clicking = false;
 	_click_io.reset (new ClickIO (*this, "click"));
 	_click_gain.reset (new Amp (*this));
 	_click_gain->activate ();
-	
-	if (state_tree && (child = find_named_node (*state_tree->root(), "Click")) != 0) {
+	if (state_tree) {
+		setup_click_state (*state_tree->root());
+	}
+}
+
+void
+Session::setup_click_state (const XMLNode& node)
+{	
+	const XMLNode* child = 0;
+
+	if ((child = find_named_node (node, "Click")) != 0) {
 		
 		/* existing state for Click */
 		int c = 0;
@@ -1406,7 +1428,7 @@ Session::audible_frame () const
 		offset = current_block_size;
 	}
 
-	if (synced_to_jack()) {
+	if (synced_to_engine()) {
 		tf = _engine.transport_frame();
 	} else {
 		tf = _transport_frame;
diff --git a/libs/ardour/session_state.cc b/libs/ardour/session_state.cc
index 1a605d2fd5..59bb3fd718 100644
--- a/libs/ardour/session_state.cc
+++ b/libs/ardour/session_state.cc
@@ -494,9 +494,10 @@ Session::create (const string& session_template, BusProfile* bus_profile)
 		ifstream in(in_path.c_str());
 
 		if (in) {
-			string out_path = _path;
-			out_path += _name;
-			out_path += statefile_suffix;
+			/* no need to call legalize_for_path() since the string
+			 * in session_template is already a legal path name
+			 */
+			string out_path = Glib::build_filename (_session_dir->root_path(), _name + statefile_suffix);
 
 			ofstream out(out_path.c_str());
 
@@ -1317,13 +1318,7 @@ Session::set_state (const XMLNode& node, int version)
 	if ((child = find_named_node (node, "Click")) == 0) {
 		warning << _("Session: XML state has no click section") << endmsg;
 	} else if (_click_io) {
-		const XMLNodeList& children (child->children());
-		XMLNodeList::const_iterator i = children.begin();
-		_click_io->set_state (**i, version);
-		++i;
-		if (i != children.end()) {
-			_click_gain->set_state (**i, version);
-		}
+		setup_click_state (node);
 	}
 
 	if ((child = find_named_node (node, ControlProtocolManager::state_node_name)) != 0) {
@@ -3781,3 +3776,68 @@ Session::rename (const std::string& new_name)
 
 #undef RENAME
 }
+
+int
+Session::get_session_info_from_path (XMLTree& tree, const string& xmlpath)
+{
+	if (!Glib::file_test (xmlpath, Glib::FILE_TEST_EXISTS)) {
+		return -1;
+        }
+
+	if (!tree.read (xmlpath)) {
+		return -1;
+	}
+
+	return 0;
+}
+
+int
+Session::get_info_from_path (const string& xmlpath, float& sample_rate, SampleFormat& data_format)
+{
+	XMLTree tree;
+	bool found_sr = false;
+	bool found_data_format = false;
+
+	if (get_session_info_from_path (tree, xmlpath)) {
+		return -1;
+	}
+
+	/* sample rate */
+
+	const XMLProperty* prop;
+	if ((prop = tree.root()->property (X_("sample-rate"))) != 0) {		
+		sample_rate = atoi (prop->value());
+		found_sr = true;
+	}
+
+	const XMLNodeList& children (tree.root()->children());
+	for (XMLNodeList::const_iterator c = children.begin(); c != children.end(); ++c) {
+		const XMLNode* child = *c;
+		if (child->name() == "Config") {
+			const XMLNodeList& options (child->children());
+			for (XMLNodeList::const_iterator oc = options.begin(); oc != options.end(); ++oc) {
+				const XMLNode* option = *oc;
+				const XMLProperty* name = option->property("name");
+
+				if (!name) {
+					continue;
+				}
+
+				if (name->value() == "native-file-data-format") {
+					const XMLProperty* value = option->property ("value");
+					if (value) {
+						SampleFormat fmt = (SampleFormat) string_2_enum (option->property ("value")->value(), fmt);
+						data_format = fmt;
+						found_data_format = true;
+						break;
+					}
+				}
+			}
+		}
+		if (found_data_format) {
+			break;
+		}
+	}
+
+	return !(found_sr && found_data_format); // zero if they are both found
+}
diff --git a/libs/ardour/session_time.cc b/libs/ardour/session_time.cc
index 0f2186c09b..e35910f2df 100644
--- a/libs/ardour/session_time.cc
+++ b/libs/ardour/session_time.cc
@@ -182,7 +182,7 @@ Session::timecode_time (Timecode::Time &t)
 int
 Session::backend_sync_callback (TransportState state, framepos_t pos)
 {
-	bool slave = synced_to_jack();
+	bool slave = synced_to_engine();
 
 	switch (state) {
 	case TransportStopped:
diff --git a/libs/ardour/session_transport.cc b/libs/ardour/session_transport.cc
index ab6d68fd67..38ad521235 100644
--- a/libs/ardour/session_transport.cc
+++ b/libs/ardour/session_transport.cc
@@ -86,7 +86,7 @@ Session::request_sync_source (Slave* new_slave)
 
 	seamless = Config->get_seamless_loop ();
 
-	if (dynamic_cast<JACK_Slave*>(new_slave)) {
+	if (dynamic_cast<Engine_Slave*>(new_slave)) {
 		/* JACK cannot support seamless looping at present */
 		Config->set_seamless_loop (false);
 	} else {
@@ -514,13 +514,13 @@ Session::non_realtime_stop (bool abort, int on_entry, bool& finished)
 	if (auto_return_enabled ||
 	    (ptw & PostTransportLocate) ||
 	    (_requested_return_frame >= 0) ||
-	    synced_to_jack()) {
+	    synced_to_engine()) {
 
 		if (pending_locate_flush) {
 			flush_all_inserts ();
 		}
 
-		if ((auto_return_enabled || synced_to_jack() || _requested_return_frame >= 0) &&
+		if ((auto_return_enabled || synced_to_engine() || _requested_return_frame >= 0) &&
 		    !(ptw & PostTransportLocate)) {
 
 			/* no explicit locate queued */
@@ -543,7 +543,7 @@ Session::non_realtime_stop (bool abort, int on_entry, bool& finished)
 
 						/* don't try to handle loop play when synced to JACK */
 
-						if (!synced_to_jack()) {
+						if (!synced_to_engine()) {
 
 							Location *location = _locations->auto_loop_location();
 
@@ -734,7 +734,7 @@ Session::set_play_loop (bool yn)
 		return;
 	}
 
-	if (yn && Config->get_seamless_loop() && synced_to_jack()) {
+	if (yn && Config->get_seamless_loop() && synced_to_engine()) {
 		warning << string_compose (
 			_("Seamless looping cannot be supported while %1 is using JACK transport.\n"
 			  "Recommend changing the configured options"), PROGRAM_NAME)
@@ -811,7 +811,7 @@ Session::flush_all_inserts ()
 void
 Session::start_locate (framepos_t target_frame, bool with_roll, bool with_flush, bool with_loop, bool force)
 {
-	if (synced_to_jack()) {
+	if (synced_to_engine()) {
 
 		double sp;
 		framepos_t pos;
@@ -926,7 +926,7 @@ Session::locate (framepos_t target_frame, bool with_roll, bool with_flush, bool
 
 	bool transport_was_stopped = !transport_rolling();
 
-	if (transport_was_stopped && (!auto_play_legal || !config.get_auto_play()) && !with_roll && !(synced_to_jack() && play_loop)) {
+	if (transport_was_stopped && (!auto_play_legal || !config.get_auto_play()) && !with_roll && !(synced_to_engine() && play_loop)) {
 		realtime_stop (false, true); // XXX paul - check if the 2nd arg is really correct
 		transport_was_stopped = true;
 	} else {
@@ -1067,7 +1067,7 @@ Session::set_transport_speed (double speed, bool abort, bool clear_state, bool a
 			set_track_monitor_input_status (true);
 		}
 
-		if (synced_to_jack ()) {
+		if (synced_to_engine ()) {
 			if (clear_state) {
 				/* do this here because our response to the slave won't
 				   take care of it.
@@ -1090,7 +1090,7 @@ Session::set_transport_speed (double speed, bool abort, bool clear_state, bool a
 			set_track_monitor_input_status (false);
 		}
 
-		if (synced_to_jack()) {
+		if (synced_to_engine()) {
 			_engine.transport_start ();
 		} else {
 			start_transport ();
@@ -1100,7 +1100,7 @@ Session::set_transport_speed (double speed, bool abort, bool clear_state, bool a
 
 		/* not zero, not 1.0 ... varispeed */
 
-		if ((synced_to_jack()) && speed != 0.0 && speed != 1.0) {
+		if ((synced_to_engine()) && speed != 0.0 && speed != 1.0) {
 			warning << string_compose (
 				_("Global varispeed cannot be supported while %1 is connected to JACK transport control"),
 				PROGRAM_NAME)
@@ -1429,8 +1429,8 @@ Session::switch_to_sync_source (SyncSource src)
 		}
 		break;
 
-	case JACK:
-		if (_slave && dynamic_cast<JACK_Slave*>(_slave)) {
+	case Engine:
+		if (_slave && dynamic_cast<Engine_Slave*>(_slave)) {
 			return;
 		}
 
@@ -1438,7 +1438,7 @@ Session::switch_to_sync_source (SyncSource src)
 			return;
 		}
 
-		new_slave = new JACK_Slave (*AudioEngine::instance());
+		new_slave = new Engine_Slave (*AudioEngine::instance());
 		break;
 
 	default:
@@ -1632,9 +1632,9 @@ bool
 Session::maybe_stop (framepos_t limit)
 {
 	if ((_transport_speed > 0.0f && _transport_frame >= limit) || (_transport_speed < 0.0f && _transport_frame == 0)) {
-		if (synced_to_jack () && config.get_jack_time_master ()) {
+		if (synced_to_engine () && config.get_jack_time_master ()) {
 			_engine.transport_stop ();
-		} else if (!synced_to_jack ()) {
+		} else if (!synced_to_engine ()) {
 			stop_transport ();
 		}
 		return true;
diff --git a/libs/ardour/utils.cc b/libs/ardour/utils.cc
index f23f1332b8..5356616324 100644
--- a/libs/ardour/utils.cc
+++ b/libs/ardour/utils.cc
@@ -397,12 +397,12 @@ string_to_sync_source (string str)
 	}
 
 	if (str == _("JACK")) {
-		return JACK;
+		return Engine;
 	}
 
 	fatal << string_compose (_("programming error: unknown sync source string \"%1\""), str) << endmsg;
 	/*NOTREACHED*/
-	return JACK;
+	return Engine;
 }
 
 /** @param sh Return a short version of the string */
@@ -410,7 +410,10 @@ const char*
 sync_source_to_string (SyncSource src, bool sh)
 {
 	switch (src) {
-	case JACK:
+	case Engine:
+		/* no other backends offer sync for now ... deal with this if we
+		 * ever have to.
+		 */
 		return _("JACK");
 
 	case MTC:
diff --git a/libs/ardour/wscript b/libs/ardour/wscript
index e8c9fb8328..6e57c455fa 100644
--- a/libs/ardour/wscript
+++ b/libs/ardour/wscript
@@ -70,6 +70,7 @@ libardour_sources = [
         'diskstream.cc',
         'element_import_handler.cc',
         'element_importer.cc',
+        'engine_slave.cc',
         'enums.cc',
         'event_type_map.cc',
         'export_channel.cc',
@@ -104,7 +105,6 @@ libardour_sources = [
         'interpolation.cc',
         'io.cc',
         'io_processor.cc',
-        'jack_slave.cc',
         'kmeterdsp.cc',
         'ladspa_plugin.cc',
         'ladspa_search_path.cc',
@@ -347,7 +347,7 @@ def build(bld):
                         'AUDIOUNITS', 'OSX','BOOST','CURL','DL']
     obj.use          = ['libpbd','libmidipp','libevoral','libvamphost',
                         'libvampplugin','libtaglib','librubberband',
-                        'libaudiographer','libltc']
+                        'libaudiographer','libltc','libtimecode']
     obj.vnum         = LIBARDOUR_LIB_VERSION
     obj.install_path = os.path.join(bld.env['LIBDIR'], 'ardour3')
     obj.defines      = [