use PortEngineSharedImpl with DummyAudioBackend

2 files changed, 84 insertions, 700 deletions

diff --git a/libs/backends/dummy/dummy_audiobackend.cc b/libs/backends/dummy/dummy_audiobackend.cc
index a9d39478fd..bf87b3275c 100644
--- a/libs/backends/dummy/dummy_audiobackend.cc
+++ b/libs/backends/dummy/dummy_audiobackend.cc
@@ -36,9 +36,10 @@
 
 #include "pbd/error.h"
 #include "pbd/compose.h"
-#include "ardour/port_manager.h"
 #include "pbd/i18n.h"
 
+#include "ardour/port_manager.h"
+
 using namespace ARDOUR;
 
 static std::string s_instance_name;
@@ -57,6 +58,7 @@ static int64_t _x_get_monotonic_usec() {
 
 DummyAudioBackend::DummyAudioBackend (AudioEngine& e, AudioBackendInfo& info)
 	: AudioBackend (e, info)
+	, PortEngineSharedImpl (e, s_instance_name)
 	, _running (false)
 	, _freewheel (false)
 	, _freewheeling (false)
@@ -261,18 +263,18 @@ DummyAudioBackend::set_buffer_size (uint32_t bs)
 	 */
 	LatencyRange lr;
 	lr.min = lr.max = _systemic_input_latency;
-	for (std::vector<DummyAudioPort*>::const_iterator it = _system_inputs.begin (); it != _system_inputs.end (); ++it) {
+	for (std::vector<BackendPort*>::const_iterator it = _system_inputs.begin (); it != _system_inputs.end (); ++it) {
 		set_latency_range (*it, false, lr);
 	}
-	for (std::vector<DummyMidiPort*>::const_iterator it = _system_midi_in.begin (); it != _system_midi_in.end (); ++it) {
+	for (std::vector<BackendPort*>::const_iterator it = _system_midi_in.begin (); it != _system_midi_in.end (); ++it) {
 		set_latency_range (*it, false, lr);
 	}
 
 	lr.min = lr.max = _systemic_output_latency;
-	for (std::vector<DummyAudioPort*>::const_iterator it = _system_outputs.begin (); it != _system_outputs.end (); ++it) {
+	for (std::vector<BackendPort*>::const_iterator it = _system_outputs.begin (); it != _system_outputs.end (); ++it) {
 		set_latency_range (*it, true, lr);
 	}
-	for (std::vector<DummyMidiPort*>::const_iterator it = _system_midi_out.begin (); it != _system_midi_out.end (); ++it) {
+	for (std::vector<BackendPort*>::const_iterator it = _system_midi_out.begin (); it != _system_midi_out.end (); ++it) {
 		set_latency_range (*it, true, lr);
 	}
 
@@ -441,21 +443,7 @@ DummyAudioBackend::_start (bool /*for_latency_measurement*/)
 		return BackendReinitializationError;
 	}
 
-	if (_ports.size () || _portmap.size ()) {
-		PBD::warning << _("DummyAudioBackend: recovering from unclean shutdown, port registry is not empty.") << endmsg;
-		for (PortIndex::const_iterator it = _ports.begin (); it != _ports.end (); ++it) {
-			PBD::info << _("DummyAudioBackend: port '") << (*it)->name () << "' exists." << endmsg;
-		}
-		for (PortMap::const_iterator it = _portmap.begin (); it != _portmap.end (); ++it) {
-			PBD::info << _("DummyAudioBackend: portmap '") << (*it).first << "' exists." << endmsg;
-		}
-		_system_inputs.clear();
-		_system_outputs.clear();
-		_system_midi_in.clear();
-		_system_midi_out.clear();
-		_ports.clear();
-		_portmap.clear();
-	}
+	clear_ports ();
 
 	if (register_system_ports()) {
 		PBD::error << _("DummyAudioBackend: failed to register system ports.") << endmsg;
@@ -643,195 +631,6 @@ DummyAudioBackend::my_name () const
 	return _instance_name;
 }
 
-uint32_t
-DummyAudioBackend::port_name_size () const
-{
-	return 256;
-}
-
-int
-DummyAudioBackend::set_port_name (PortEngine::PortHandle port, const std::string& name)
-{
-	std::string newname (_instance_name + ":" + name);
-
-	if (!valid_port (port)) {
-		PBD::error << _("DummyBackend::set_port_name: Invalid Port(s)") << endmsg;
-		return -1;
-	}
-
-	if (find_port (newname)) {
-		PBD::error << _("DummyBackend::set_port_name: Port with given name already exists") << endmsg;
-		return -1;
-	}
-
-	DummyPort* p = static_cast<DummyPort*>(port);
-	_portmap.erase (p->name());
-	_portmap.insert (make_pair (newname, p));
-	return p->set_name (newname);
-}
-
-std::string
-DummyAudioBackend::get_port_name (PortEngine::PortHandle port) const
-{
-	if (!valid_port (port)) {
-		PBD::error << _("DummyBackend::get_port_name: Invalid Port(s)") << endmsg;
-		return std::string ();
-	}
-	return static_cast<DummyPort*>(port)->name ();
-}
-
-PortFlags
-DummyAudioBackend::get_port_flags (PortEngine::PortHandle port) const
-{
-	if (!valid_port (port)) {
-		PBD::error << _("DummyBackend::get_port_flags: Invalid Port(s)") << endmsg;
-		return PortFlags (0);
-	}
-	return static_cast<DummyPort*>(port)->flags ();
-}
-
-int
-DummyAudioBackend::get_port_property (PortHandle port, const std::string& key, std::string& value, std::string& type) const
-{
-	if (!valid_port (port)) {
-		PBD::warning << _("DummyBackend::get_port_property: Invalid Port(s)") << endmsg;
-		return -1;
-	}
-	if (key == "http://jackaudio.org/metadata/pretty-name") {
-		type = "";
-		value = static_cast<DummyPort*>(port)->pretty_name ();
-		if (!value.empty()) {
-			return 0;
-		}
-	}
-	return -1;
-}
-
-int
-DummyAudioBackend::set_port_property (PortHandle port, const std::string& key, const std::string& value, const std::string& type)
-{
-	if (!valid_port (port)) {
-		PBD::warning << _("DummyBackend::set_port_property: Invalid Port(s)") << endmsg;
-		return -1;
-	}
-	if (key == "http://jackaudio.org/metadata/pretty-name" && type.empty ()) {
-		static_cast<DummyPort*>(port)->set_pretty_name (value);
-		return 0;
-	}
-	return -1;
-}
-
-PortEngine::PortHandle
-DummyAudioBackend::get_port_by_name (const std::string& name) const
-{
-	PortHandle port = (PortHandle) find_port (name);
-	return port;
-}
-
-int
-DummyAudioBackend::get_ports (
-		const std::string& port_name_pattern,
-		DataType type, PortFlags flags,
-		std::vector<std::string>& port_names) const
-{
-	int rv = 0;
-	regex_t port_regex;
-	bool use_regexp = false;
-	if (port_name_pattern.size () > 0) {
-		if (!regcomp (&port_regex, port_name_pattern.c_str (), REG_EXTENDED|REG_NOSUB)) {
-			use_regexp = true;
-		}
-	}
-
-	for (PortIndex::const_iterator i = _ports.begin (); i != _ports.end (); ++i) {
-		DummyPort* port = *i;
-		if ((port->type () == type) && flags == (port->flags () & flags)) {
-			if (!use_regexp || !regexec (&port_regex, port->name ().c_str (), 0, NULL, 0)) {
-				port_names.push_back (port->name ());
-				++rv;
-			}
-		}
-	}
-	if (use_regexp) {
-		regfree (&port_regex);
-	}
-	return rv;
-}
-
-DataType
-DummyAudioBackend::port_data_type (PortEngine::PortHandle port) const
-{
-	if (!valid_port (port)) {
-		return DataType::NIL;
-	}
-	return static_cast<DummyPort*>(port)->type ();
-}
-
-PortEngine::PortHandle
-DummyAudioBackend::register_port (
-		const std::string& name,
-		ARDOUR::DataType type,
-		ARDOUR::PortFlags flags)
-{
-	if (name.size () == 0) { return 0; }
-	if (flags & IsPhysical) { return 0; }
-	if (!_running) {
-		PBD::info << _("DummyBackend::register_port: Engine is not running.") << endmsg;
-	}
-	return add_port (_instance_name + ":" + name, type, flags);
-}
-
-PortEngine::PortHandle
-DummyAudioBackend::add_port (
-		const std::string& name,
-		ARDOUR::DataType type,
-		ARDOUR::PortFlags flags)
-{
-	assert(name.size ());
-	if (find_port (name)) {
-		PBD::error << _("DummyBackend::register_port: Port already exists:")
-				<< " (" << name << ")" << endmsg;
-		return 0;
-	}
-	DummyPort* port = NULL;
-	switch (type) {
-		case DataType::AUDIO:
-			port = new DummyAudioPort (*this, name, flags);
-			break;
-		case DataType::MIDI:
-			port = new DummyMidiPort (*this, name, flags);
-			break;
-		default:
-			PBD::error << _("DummyBackend::register_port: Invalid Data Type.") << endmsg;
-			return 0;
-	}
-
-	_ports.insert (port);
-	_portmap.insert (make_pair (name, port));
-
-	return port;
-}
-
-void
-DummyAudioBackend::unregister_port (PortEngine::PortHandle port_handle)
-{
-	if (!_running) {
-		PBD::info << _("DummyBackend::unregister_port: Engine is not running.") << endmsg;
-		assert (!valid_port (port_handle));
-		return;
-	}
-	DummyPort* port = static_cast<DummyPort*>(port_handle);
-	PortIndex::iterator i = std::find (_ports.begin(), _ports.end(), static_cast<DummyPort*>(port_handle));
-	if (i == _ports.end ()) {
-		PBD::error << _("DummyBackend::unregister_port: Failed to find port") << endmsg;
-		return;
-	}
-	disconnect_all(port_handle);
-	_portmap.erase (port->name());
-	_ports.erase (i);
-	delete port;
-}
-
 int
 DummyAudioBackend::register_system_ports()
 {
@@ -957,163 +756,41 @@ DummyAudioBackend::register_system_ports()
 }
 
 void
-DummyAudioBackend::unregister_ports (bool system_only)
-{
-	_system_inputs.clear();
-	_system_outputs.clear();
-	_system_midi_in.clear();
-	_system_midi_out.clear();
-
-	for (PortIndex::iterator i = _ports.begin (); i != _ports.end ();) {
-		PortIndex::iterator cur = i++;
-		DummyPort* port = *cur;
-		if (! system_only || (port->is_physical () && port->is_terminal ())) {
-			port->disconnect_all ();
-			_portmap.erase (port->name());
-			delete port;
-			_ports.erase (cur);
-		}
-	}
-}
-
-void
 DummyAudioBackend::update_system_port_latecies ()
 {
-	for (std::vector<DummyAudioPort*>::const_iterator it = _system_inputs.begin (); it != _system_inputs.end (); ++it) {
+	for (std::vector<BackendPort*>::const_iterator it = _system_inputs.begin (); it != _system_inputs.end (); ++it) {
 		(*it)->update_connected_latency (true);
 	}
-	for (std::vector<DummyAudioPort*>::const_iterator it = _system_outputs.begin (); it != _system_outputs.end (); ++it) {
+	for (std::vector<BackendPort*>::const_iterator it = _system_outputs.begin (); it != _system_outputs.end (); ++it) {
 		(*it)->update_connected_latency (false);
 	}
 
-	for (std::vector<DummyMidiPort*>::const_iterator it = _system_midi_in.begin (); it != _system_midi_in.end (); ++it) {
+	for (std::vector<BackendPort*>::const_iterator it = _system_midi_in.begin (); it != _system_midi_in.end (); ++it) {
 		(*it)->update_connected_latency (true);
 	}
-	for (std::vector<DummyMidiPort*>::const_iterator it = _system_midi_out.begin (); it != _system_midi_out.end (); ++it) {
+	for (std::vector<BackendPort*>::const_iterator it = _system_midi_out.begin (); it != _system_midi_out.end (); ++it) {
 		(*it)->update_connected_latency (false);
 	}
 }
 
-int
-DummyAudioBackend::connect (const std::string& src, const std::string& dst)
-{
-	DummyPort* src_port = find_port (src);
-	DummyPort* dst_port = find_port (dst);
-
-	if (!src_port) {
-		PBD::error << _("DummyBackend::connect: Invalid Source port:")
-				<< " (" << src <<")" << endmsg;
-		return -1;
-	}
-	if (!dst_port) {
-		PBD::error << _("DummyBackend::connect: Invalid Destination port:")
-			<< " (" << dst <<")" << endmsg;
-		return -1;
-	}
-	return src_port->connect (dst_port);
-}
-
-int
-DummyAudioBackend::disconnect (const std::string& src, const std::string& dst)
-{
-	DummyPort* src_port = find_port (src);
-	DummyPort* dst_port = find_port (dst);
-
-	if (!src_port || !dst_port) {
-		PBD::error << _("DummyBackend::disconnect: Invalid Port(s)") << endmsg;
-		return -1;
-	}
-	return src_port->disconnect (dst_port);
-}
-
-int
-DummyAudioBackend::connect (PortEngine::PortHandle src, const std::string& dst)
-{
-	DummyPort* dst_port = find_port (dst);
-	if (!valid_port (src)) {
-		PBD::error << _("DummyBackend::connect: Invalid Source Port Handle") << endmsg;
-		return -1;
-	}
-	if (!dst_port) {
-		PBD::error << _("DummyBackend::connect: Invalid Destination Port")
-			<< " (" << dst << ")" << endmsg;
-		return -1;
-	}
-	return static_cast<DummyPort*>(src)->connect (dst_port);
-}
-
-int
-DummyAudioBackend::disconnect (PortEngine::PortHandle src, const std::string& dst)
-{
-	DummyPort* dst_port = find_port (dst);
-	if (!valid_port (src) || !dst_port) {
-		PBD::error << _("DummyBackend::disconnect: Invalid Port(s)") << endmsg;
-		return -1;
-	}
-	return static_cast<DummyPort*>(src)->disconnect (dst_port);
-}
-
-int
-DummyAudioBackend::disconnect_all (PortEngine::PortHandle port)
-{
-	if (!valid_port (port)) {
-		PBD::error << _("DummyBackend::disconnect_all: Invalid Port") << endmsg;
-		return -1;
-	}
-	static_cast<DummyPort*>(port)->disconnect_all ();
-	return 0;
-}
-
-bool
-DummyAudioBackend::connected (PortEngine::PortHandle port, bool /* process_callback_safe*/)
-{
-	if (!valid_port (port)) {
-		PBD::error << _("DummyBackend::disconnect_all: Invalid Port") << endmsg;
-		return false;
-	}
-	return static_cast<DummyPort*>(port)->is_connected ();
-}
-
-bool
-DummyAudioBackend::connected_to (PortEngine::PortHandle src, const std::string& dst, bool /*process_callback_safe*/)
-{
-	DummyPort* dst_port = find_port (dst);
-#ifndef NDEBUG
-	if (!valid_port (src) || !dst_port) {
-		PBD::error << _("DummyBackend::connected_to: Invalid Port") << endmsg;
-		return false;
-	}
-#endif
-	return static_cast<DummyPort*>(src)->is_connected (dst_port);
-}
-
-bool
-DummyAudioBackend::physically_connected (PortEngine::PortHandle port, bool /*process_callback_safe*/)
+BackendPort*
+DummyAudioBackend::port_factory (std::string const & name, ARDOUR::DataType type, ARDOUR::PortFlags flags)
 {
-	if (!valid_port (port)) {
-		PBD::error << _("DummyBackend::physically_connected: Invalid Port") << endmsg;
-		return false;
-	}
-	return static_cast<DummyPort*>(port)->is_physically_connected ();
-}
-
-int
-DummyAudioBackend::get_connections (PortEngine::PortHandle port, std::vector<std::string>& names, bool /*process_callback_safe*/)
-{
-	if (!valid_port (port)) {
-		PBD::error << _("DummyBackend::get_connections: Invalid Port") << endmsg;
-		return -1;
-	}
-
-	assert (0 == names.size ());
+	BackendPort* port = 0;
 
-	const std::set<DummyPort*>& connected_ports = static_cast<DummyPort*>(port)->get_connections ();
-
-	for (std::set<DummyPort*>::const_iterator i = connected_ports.begin (); i != connected_ports.end (); ++i) {
-		names.push_back ((*i)->name ());
+	switch (type) {
+		case DataType::AUDIO:
+			port = new DummyAudioPort (*this, name, flags);
+			break;
+		case DataType::MIDI:
+			port = new DummyMidiPort (*this, name, flags);
+			break;
+		default:
+			PBD::error << string_compose (_("%1::register_port: Invalid Data Type."), _instance_name) << endmsg;
+			return 0;
 	}
 
-	return (int)names.size ();
+	return port;
 }
 
 /* MIDI */
@@ -1243,82 +920,6 @@ DummyAudioBackend::get_latency_range (PortEngine::PortHandle port, bool for_play
 	return r;
 }
 
-/* Discovering physical ports */
-
-bool
-DummyAudioBackend::port_is_physical (PortEngine::PortHandle port) const
-{
-	if (!valid_port (port)) {
-		PBD::error << _("DummyPort::port_is_physical (): invalid port.") << endmsg;
-		return false;
-	}
-	return static_cast<DummyPort*>(port)->is_physical ();
-}
-
-void
-DummyAudioBackend::get_physical_outputs (DataType type, std::vector<std::string>& port_names)
-{
-	for (PortIndex::iterator i = _ports.begin (); i != _ports.end (); ++i) {
-		DummyPort* port = *i;
-		if ((port->type () == type) && port->is_input () && port->is_physical ()) {
-			port_names.push_back (port->name ());
-		}
-	}
-}
-
-void
-DummyAudioBackend::get_physical_inputs (DataType type, std::vector<std::string>& port_names)
-{
-	for (PortIndex::iterator i = _ports.begin (); i != _ports.end (); ++i) {
-		DummyPort* port = *i;
-		if ((port->type () == type) && port->is_output () && port->is_physical ()) {
-			port_names.push_back (port->name ());
-		}
-	}
-}
-
-ChanCount
-DummyAudioBackend::n_physical_outputs () const
-{
-	int n_midi = 0;
-	int n_audio = 0;
-	for (PortIndex::const_iterator i = _ports.begin (); i != _ports.end (); ++i) {
-		DummyPort* port = *i;
-		if (port->is_output () && port->is_physical ()) {
-			switch (port->type ()) {
-				case DataType::AUDIO: ++n_audio; break;
-				case DataType::MIDI: ++n_midi; break;
-				default: break;
-			}
-		}
-	}
-	ChanCount cc;
-	cc.set (DataType::AUDIO, n_audio);
-	cc.set (DataType::MIDI, n_midi);
-	return cc;
-}
-
-ChanCount
-DummyAudioBackend::n_physical_inputs () const
-{
-	int n_midi = 0;
-	int n_audio = 0;
-	for (PortIndex::const_iterator i = _ports.begin (); i != _ports.end (); ++i) {
-		DummyPort* port = *i;
-		if (port->is_input () && port->is_physical ()) {
-			switch (port->type ()) {
-				case DataType::AUDIO: ++n_audio; break;
-				case DataType::MIDI: ++n_midi; break;
-				default: break;
-			}
-		}
-	}
-	ChanCount cc;
-	cc.set (DataType::AUDIO, n_audio);
-	cc.set (DataType::MIDI, n_midi);
-	return cc;
-}
-
 /* Getting access to the data buffer for a port */
 
 void*
@@ -1351,11 +952,11 @@ DummyAudioBackend::main_process_thread ()
 		}
 
 		// re-set input buffers, generate on demand.
-		for (std::vector<DummyAudioPort*>::const_iterator it = _system_inputs.begin (); it != _system_inputs.end (); ++it) {
-			(*it)->next_period();
+		for (std::vector<BackendPort*>::const_iterator it = _system_inputs.begin (); it != _system_inputs.end (); ++it) {
+			static_cast<DummyPort*>(*it)->next_period();
 		}
-		for (std::vector<DummyMidiPort*>::const_iterator it = _system_midi_in.begin (); it != _system_midi_in.end (); ++it) {
-			(*it)->next_period();
+		for (std::vector<BackendPort*>::const_iterator it = _system_midi_in.begin (); it != _system_midi_in.end (); ++it) {
+			static_cast<DummyPort*>(*it)->next_period();
 		}
 
 		if (engine.process_callback (samples_per_period)) {
@@ -1366,28 +967,28 @@ DummyAudioBackend::main_process_thread ()
 		if (_device == _("Loopback") && _midi_mode != MidiToAudio) {
 			int opn = 0;
 			int opc = _system_outputs.size();
-			for (std::vector<DummyAudioPort*>::const_iterator it = _system_inputs.begin (); it != _system_inputs.end (); ++it, ++opn) {
-				DummyAudioPort* op = _system_outputs[(opn % opc)];
-				(*it)->fill_wavetable ((const float*)op->get_buffer (samples_per_period), samples_per_period);
+			for (std::vector<BackendPort*>::const_iterator it = _system_inputs.begin (); it != _system_inputs.end (); ++it, ++opn) {
+				DummyAudioPort* op = static_cast<DummyAudioPort*> (_system_outputs[(opn % opc)]);
+				static_cast<DummyAudioPort*>(*it)->fill_wavetable ((const float*)op->get_buffer (samples_per_period), samples_per_period);
 			}
 		}
 
 		if (_midi_mode == MidiLoopback) {
 			int opn = 0;
 			int opc = _system_midi_out.size();
-			for (std::vector<DummyMidiPort*>::const_iterator it = _system_midi_in.begin (); it != _system_midi_in.end (); ++it, ++opn) {
-				DummyMidiPort* op = _system_midi_out[(opn % opc)];
+			for (std::vector<BackendPort*>::const_iterator it = _system_midi_in.begin (); it != _system_midi_in.end (); ++it, ++opn) {
+				DummyMidiPort* op = static_cast<DummyMidiPort*> (_system_midi_out[(opn % opc)]);
 				op->get_buffer(0); // mix-down
-				(*it)->set_loopback (op->const_buffer());
+				static_cast<DummyMidiPort*>(*it)->set_loopback (op->const_buffer());
 			}
 		}
 		else if (_midi_mode == MidiToAudio) {
 			int opn = 0;
 			int opc = _system_midi_out.size();
-			for (std::vector<DummyAudioPort*>::const_iterator it = _system_inputs.begin (); it != _system_inputs.end (); ++it, ++opn) {
-				DummyMidiPort* op = _system_midi_out[(opn % opc)];
+			for (std::vector<BackendPort*>::const_iterator it = _system_inputs.begin (); it != _system_inputs.end (); ++it, ++opn) {
+				DummyMidiPort* op = static_cast<DummyMidiPort*> (_system_midi_out[(opn % opc)]);
 				op->get_buffer(0); // mix-down
-				(*it)->midi_to_wavetable (op->const_buffer(), samples_per_period);
+				static_cast<DummyAudioPort*>(*it)->midi_to_wavetable (op->const_buffer(), samples_per_period);
 			}
 		}
 
@@ -1515,158 +1116,17 @@ extern "C" ARDOURBACKEND_API ARDOUR::AudioBackendInfo* descriptor ()
 
 /******************************************************************************/
 DummyPort::DummyPort (DummyAudioBackend &b, const std::string& name, PortFlags flags)
-	: _dummy_backend (b)
-	, _name  (name)
-	, _flags (flags)
+	: BackendPort (b, name, flags)
 	, _rseed (0)
 	, _gen_cycle (false)
+	, _engine (b)
 {
-	_capture_latency_range.min = 0;
-	_capture_latency_range.max = 0;
-	_playback_latency_range.min = 0;
-	_playback_latency_range.max = 0;
-	_dummy_backend.port_connect_add_remove_callback();
+	_backend.port_connect_add_remove_callback();
 }
 
-DummyPort::~DummyPort () {
-	disconnect_all ();
-	_dummy_backend.port_connect_add_remove_callback();
-}
-
-
-int DummyPort::connect (DummyPort *port)
-{
-	if (!port) {
-		PBD::error << _("DummyPort::connect (): invalid (null) port") << endmsg;
-		return -1;
-	}
-
-	if (type () != port->type ()) {
-		PBD::error << _("DummyPort::connect (): wrong port-type") << endmsg;
-		return -1;
-	}
-
-	if (is_output () && port->is_output ()) {
-		PBD::error << _("DummyPort::connect (): cannot inter-connect output ports.") << endmsg;
-		return -1;
-	}
-
-	if (is_input () && port->is_input ()) {
-		PBD::error << _("DummyPort::connect (): cannot inter-connect input ports.") << endmsg;
-		return -1;
-	}
-
-	if (this == port) {
-		PBD::error << _("DummyPort::connect (): cannot self-connect ports.") << endmsg;
-		return -1;
-	}
-
-	if (is_connected (port)) {
-#if 0 // don't bother to warn about this for now. just ignore it
-		PBD::error << _("DummyPort::connect (): ports are already connected:")
-			<< " (" << name () << ") -> (" << port->name () << ")"
-			<< endmsg;
-#endif
-		return -1;
-	}
-
-	_connect (port, true);
-	return 0;
-}
-
-
-void DummyPort::_connect (DummyPort *port, bool callback)
-{
-	_connections.insert (port);
-	if (callback) {
-		port->_connect (this, false);
-		_dummy_backend.port_connect_callback (name(),  port->name(), true);
-	}
-}
-
-int DummyPort::disconnect (DummyPort *port)
-{
-	if (!port) {
-		PBD::error << _("DummyPort::disconnect (): invalid (null) port") << endmsg;
-		return -1;
-	}
-
-	if (!is_connected (port)) {
-		PBD::error << _("DummyPort::disconnect (): ports are not connected:")
-			<< " (" << name () << ") -> (" << port->name () << ")"
-			<< endmsg;
-		return -1;
-	}
-	_disconnect (port, true);
-	return 0;
-}
-
-void DummyPort::_disconnect (DummyPort *port, bool callback)
-{
-	std::set<DummyPort*>::iterator it = _connections.find (port);
-	assert (it != _connections.end ());
-	_connections.erase (it);
-	if (callback) {
-		port->_disconnect (this, false);
-		_dummy_backend.port_connect_callback (name(),  port->name(), false);
-	}
-}
-
-
-void DummyPort::disconnect_all ()
-{
-	while (!_connections.empty ()) {
-		std::set<DummyPort*>::iterator it = _connections.begin ();
-		(*it)->_disconnect (this, false);
-		_dummy_backend.port_connect_callback (name(), (*it)->name(), false);
-		_connections.erase (it);
-	}
-}
-
-bool
-DummyPort::is_connected (const DummyPort *port) const
-{
-	return _connections.find (const_cast<DummyPort *>(port)) != _connections.end ();
-}
-
-bool DummyPort::is_physically_connected () const
-{
-	for (std::set<DummyPort*>::const_iterator it = _connections.begin (); it != _connections.end (); ++it) {
-		if ((*it)->is_physical ()) {
-			return true;
-		}
-	}
-	return false;
-}
-
-void
-DummyPort::set_latency_range (const LatencyRange &latency_range, bool for_playback)
-{
-	if (for_playback) {
-		_playback_latency_range = latency_range;
-	} else {
-		_capture_latency_range = latency_range;
-	}
-
-	for (std::set<DummyPort*>::const_iterator it = _connections.begin (); it != _connections.end (); ++it) {
-		if ((*it)->is_physical ()) {
-			(*it)->update_connected_latency (is_input ());
-		}
-	}
-}
-
-void
-DummyPort::update_connected_latency (bool for_playback)
+DummyPort::~DummyPort ()
 {
-	LatencyRange lr;
-	lr.min = lr.max = 0;
-	for (std::set<DummyPort*>::const_iterator it = _connections.begin (); it != _connections.end (); ++it) {
-		LatencyRange l;
-		l = (*it)->latency_range (for_playback);
-		lr.min = std::max (lr.min, l.min);
-		lr.max = std::max (lr.max, l.max);
-	}
-	set_latency_range (lr, for_playback);
+	_backend.port_connect_add_remove_callback();
 }
 
 void DummyPort::setup_random_number_generator ()
@@ -1712,8 +1172,8 @@ DummyPort::randf ()
 pframes_t
 DummyPort::pulse_position () const
 {
-	samplecnt_t sr = _dummy_backend.sample_rate ();
-	samplepos_t st = _dummy_backend.sample_time_at_cycle_start();
+	samplecnt_t sr = _engine.sample_rate ();
+	samplepos_t st = _engine.sample_time_at_cycle_start();
 	return (sr - (st % sr)) % sr;
 }
 
@@ -2165,8 +1625,8 @@ void DummyAudioPort::generate (const pframes_t n_samples)
 void* DummyAudioPort::get_buffer (pframes_t n_samples)
 {
 	if (is_input ()) {
-		const std::set<DummyPort *>& connections = get_connections ();
-		std::set<DummyPort*>::const_iterator it = connections.begin ();
+		const std::set<BackendPort *>& connections = get_connections ();
+		std::set<BackendPort*>::const_iterator it = connections.begin ();
 		if (it == connections.end ()) {
 			memset (_buffer, 0, n_samples * sizeof (Sample));
 		} else {
@@ -2301,8 +1761,8 @@ void* DummyMidiPort::get_buffer (pframes_t n_samples)
 {
 	if (is_input ()) {
 		_buffer.clear ();
-		const std::set<DummyPort*>& connections = get_connections ();
-		for (std::set<DummyPort*>::const_iterator i = connections.begin ();
+		const std::set<BackendPort*>& connections = get_connections ();
+		for (std::set<BackendPort*>::const_iterator i = connections.begin ();
 				i != connections.end ();
 				++i) {
 			DummyMidiPort * source = static_cast<DummyMidiPort*>(*i);
diff --git a/libs/backends/dummy/dummy_audiobackend.h b/libs/backends/dummy/dummy_audiobackend.h
index d502f35c30..843debcccf 100644
--- a/libs/backends/dummy/dummy_audiobackend.h
+++ b/libs/backends/dummy/dummy_audiobackend.h
@@ -37,6 +37,7 @@
 #include "ardour/types.h"
 #include "ardour/audio_backend.h"
 #include "ardour/dsp_load_calculator.h"
+#include "ardour/port_engine_shared.h"
 
 namespace ARDOUR {
 
@@ -69,59 +70,14 @@ class DummyMidiEvent {
 
 typedef std::vector<boost::shared_ptr<DummyMidiEvent> > DummyMidiBuffer;
 
-class DummyPort {
+class DummyPort : public BackendPort {
 	protected:
 		DummyPort (DummyAudioBackend &b, const std::string&, PortFlags);
 	public:
 		virtual ~DummyPort ();
 
-		const std::string& name () const { return _name; }
-		const std::string& pretty_name () const { return _pretty_name; }
-		PortFlags flags () const { return _flags; }
-
-		int set_name (const std::string &name) { _name = name; return 0; }
-		int set_pretty_name (const std::string &name) { _pretty_name = name; return 0; }
-
-		virtual DataType type () const = 0;
-
-		bool is_input ()     const { return flags () & IsInput; }
-		bool is_output ()    const { return flags () & IsOutput; }
-		bool is_physical ()  const { return flags () & IsPhysical; }
-		bool is_terminal ()  const { return flags () & IsTerminal; }
-		bool is_connected () const { return _connections.size () != 0; }
-		bool is_connected (const DummyPort *port) const;
-		bool is_physically_connected () const;
-
-		const std::set<DummyPort *>& get_connections () const { return _connections; }
-
-		int connect (DummyPort *port);
-		int disconnect (DummyPort *port);
-		void disconnect_all ();
-
-		virtual void* get_buffer (pframes_t nframes) = 0;
 		void next_period () { _gen_cycle = false; }
 
-		const LatencyRange latency_range (bool for_playback) const
-		{
-			return for_playback ? _playback_latency_range : _capture_latency_range;
-		}
-
-		void set_latency_range (const LatencyRange &latency_range, bool for_playback);
-
-		void update_connected_latency (bool for_playback);
-
-	private:
-		DummyAudioBackend &_dummy_backend;
-		std::string _name;
-		std::string _pretty_name;
-		const PortFlags _flags;
-		LatencyRange _capture_latency_range;
-		LatencyRange _playback_latency_range;
-		std::set<DummyPort*> _connections;
-
-		void _connect (DummyPort* , bool);
-		void _disconnect (DummyPort* , bool);
-
 	protected:
 		/* random number generator */
 		void setup_random_number_generator ();
@@ -135,6 +91,9 @@ class DummyPort {
 		volatile bool _gen_cycle;
 		Glib::Threads::Mutex generator_lock;
 
+        private:
+		AudioBackend& _engine;
+
 }; // class DummyPort
 
 class DummyAudioPort : public DummyPort {
@@ -227,7 +186,7 @@ class DummyMidiPort : public DummyPort {
 		DummyMidiData::MIDISequence const * _midi_seq_dat;
 }; // class DummyMidiPort
 
-class DummyAudioBackend : public AudioBackend {
+class DummyAudioBackend : public AudioBackend, public PortEngineSharedImpl {
 	friend class DummyPort;
 	public:
 	         DummyAudioBackend (AudioEngine& e, AudioBackendInfo& info);
@@ -326,33 +285,35 @@ class DummyAudioBackend : public AudioBackend {
 
 		void* private_handle () const;
 		const std::string& my_name () const;
-		uint32_t port_name_size () const;
-
-		int         set_port_name (PortHandle, const std::string&);
-		std::string get_port_name (PortHandle) const;
-		PortFlags get_port_flags (PortHandle) const;
-		PortHandle  get_port_by_name (const std::string&) const;
-
-		int get_port_property (PortHandle, const std::string& key, std::string& value, std::string& type) const;
-		int set_port_property (PortHandle, const std::string& key, const std::string& value, const std::string& type);
-
-		int get_ports (const std::string& port_name_pattern, DataType type, PortFlags flags, std::vector<std::string>&) const;
 
-		DataType port_data_type (PortHandle) const;
+		/* PortEngine API - forwarded to PortEngineSharedImpl */
+
+	bool        port_is_physical (PortEngine::PortHandle ph) const { return PortEngineSharedImpl::port_is_physical (ph); }
+	void        get_physical_outputs (DataType type, std::vector<std::string>& results) { PortEngineSharedImpl::get_physical_outputs (type, results); }
+	void        get_physical_inputs (DataType type, std::vector<std::string>& results) { PortEngineSharedImpl::get_physical_inputs (type, results); }
+	ChanCount   n_physical_outputs () const { return PortEngineSharedImpl::n_physical_outputs (); }
+	ChanCount   n_physical_inputs () const { return PortEngineSharedImpl::n_physical_inputs (); }
+	uint32_t    port_name_size () const { return PortEngineSharedImpl::port_name_size(); }
+	int         set_port_name (PortEngine::PortHandle ph, const std::string& name) { return PortEngineSharedImpl::set_port_name (ph, name); }
+	std::string get_port_name (PortEngine::PortHandle ph) const { return PortEngineSharedImpl::get_port_name (ph); }
+	PortFlags   get_port_flags (PortEngine::PortHandle ph) const { return PortEngineSharedImpl::get_port_flags (ph); }
+	PortEngine::PortHandle  get_port_by_name (std::string const & name) const { return PortEngineSharedImpl::get_port_by_name (name); }
+	int         get_port_property (PortEngine::PortHandle ph, const std::string& key, std::string& value, std::string& type) const { return PortEngineSharedImpl::get_port_property (ph, key, value, type); }
+	int         set_port_property (PortEngine::PortHandle ph, const std::string& key, const std::string& value, const std::string& type) { return PortEngineSharedImpl::set_port_property (ph, key, value, type); }
+	int         get_ports (const std::string& port_name_pattern, DataType type, PortFlags flags, std::vector<std::string>& results) const { return PortEngineSharedImpl::get_ports (port_name_pattern, type, flags, results); }
+	DataType    port_data_type (PortEngine::PortHandle ph) const { return PortEngineSharedImpl::port_data_type (ph); }
+	PortEngine::PortHandle register_port (const std::string& shortname, ARDOUR::DataType type, ARDOUR::PortFlags flags) { return PortEngineSharedImpl::register_port (shortname, type, flags); }
+	void        unregister_port (PortHandle ph) { if (!_running) return; PortEngineSharedImpl::unregister_port (ph); }
+	int         connect (const std::string& src, const std::string& dst) { return PortEngineSharedImpl::connect (src, dst); }
+	int         disconnect (const std::string& src, const std::string& dst) { return PortEngineSharedImpl::disconnect (src, dst); }
+	int         connect (PortEngine::PortHandle ph, const std::string& other) { return PortEngineSharedImpl::connect (ph, other); }
+	int         disconnect (PortEngine::PortHandle ph, const std::string& other) { return PortEngineSharedImpl::disconnect (ph, other); }
+	int         disconnect_all (PortEngine::PortHandle ph) { return PortEngineSharedImpl::disconnect_all (ph); }
+	bool        connected (PortEngine::PortHandle ph, bool process_callback_safe) { return PortEngineSharedImpl::connected (ph, process_callback_safe); }
+	bool        connected_to (PortEngine::PortHandle ph, const std::string& other, bool process_callback_safe) { return PortEngineSharedImpl::connected_to (ph, other, process_callback_safe); }
+	bool        physically_connected (PortEngine::PortHandle ph, bool process_callback_safe) { return PortEngineSharedImpl::physically_connected (ph, process_callback_safe); }
+	int         get_connections (PortEngine::PortHandle ph, std::vector<std::string>& results, bool process_callback_safe) { return PortEngineSharedImpl::get_connections (ph, results, process_callback_safe); }
 
-		PortHandle register_port (const std::string& shortname, ARDOUR::DataType, ARDOUR::PortFlags);
-		void unregister_port (PortHandle);
-
-		int  connect (const std::string& src, const std::string& dst);
-		int  disconnect (const std::string& src, const std::string& dst);
-		int  connect (PortHandle, const std::string&);
-		int  disconnect (PortHandle, const std::string&);
-		int  disconnect_all (PortHandle);
-
-		bool connected (PortHandle, bool process_callback_safe);
-		bool connected_to (PortHandle, const std::string&, bool process_callback_safe);
-		bool physically_connected (PortHandle, bool process_callback_safe);
-		int  get_connections (PortHandle, std::vector<std::string>&, bool process_callback_safe);
 
 		/* MIDI */
 		int midi_event_get (pframes_t& timestamp, size_t& size, uint8_t const** buf, void* port_buffer, uint32_t event_index);
@@ -372,14 +333,6 @@ class DummyAudioBackend : public AudioBackend {
 		void         set_latency_range (PortHandle, bool for_playback, LatencyRange);
 		LatencyRange get_latency_range (PortHandle, bool for_playback);
 
-		/* Discovering physical ports */
-
-		bool      port_is_physical (PortHandle) const;
-		void      get_physical_outputs (DataType type, std::vector<std::string>&);
-		void      get_physical_inputs (DataType type, std::vector<std::string>&);
-		ChanCount n_physical_outputs () const;
-		ChanCount n_physical_inputs () const;
-
 		/* Getting access to the data buffer for a port */
 
 		void* get_buffer (PortHandle, pframes_t);
@@ -449,28 +402,9 @@ class DummyAudioBackend : public AudioBackend {
 		};
 
 		/* port engine */
-		PortHandle add_port (const std::string& shortname, ARDOUR::DataType, ARDOUR::PortFlags);
 		int register_system_ports ();
-		void unregister_ports (bool system_only = false);
 		void update_system_port_latecies ();
 
-		std::vector<DummyAudioPort *> _system_inputs;
-		std::vector<DummyAudioPort *> _system_outputs;
-		std::vector<DummyMidiPort *> _system_midi_in;
-		std::vector<DummyMidiPort *> _system_midi_out;
-
-		struct SortByPortName
-		{
-			bool operator ()(const DummyPort* lhs, const DummyPort* rhs) const
-			{
-				return PBD::naturally_less (lhs->name ().c_str (), rhs->name ().c_str ());
-			}
-		};
-
-		typedef std::map<std::string, DummyPort *> PortMap; // fast lookup in _ports
-		typedef std::set<DummyPort *, SortByPortName> PortIndex; // fast lookup in _ports
-		PortMap _portmap;
-		PortIndex _ports;
 
 		struct PortConnectData {
 			std::string a;
@@ -497,17 +431,7 @@ class DummyAudioBackend : public AudioBackend {
 			pthread_mutex_unlock (&_port_callback_mutex);
 		}
 
-		bool valid_port (PortHandle port) const {
-			return std::find (_ports.begin(), _ports.end(), static_cast<DummyPort*>(port)) != _ports.end ();
-		}
-
-		DummyPort* find_port (const std::string& port_name) const {
-			PortMap::const_iterator it = _portmap.find (port_name);
-			if (it == _portmap.end()) {
-				return NULL;
-			}
-			return (*it).second;
-		}
+	BackendPort* port_factory (std::string const & name, ARDOUR::DataType type, ARDOUR::PortFlags);
 
 }; // class DummyAudioBackend