use PortEngineSharedImpl with PulseAudio backend

2 files changed, 66 insertions, 705 deletions

diff --git a/libs/backends/pulseaudio/pulseaudio_backend.cc b/libs/backends/pulseaudio/pulseaudio_backend.cc
index 9d550a3449..fb1a058455 100644
--- a/libs/backends/pulseaudio/pulseaudio_backend.cc
+++ b/libs/backends/pulseaudio/pulseaudio_backend.cc
@@ -47,6 +47,7 @@ const size_t PulseAudioBackend::_max_buffer_size = 8192;
 
 PulseAudioBackend::PulseAudioBackend (AudioEngine& e, AudioBackendInfo& info)
 	: AudioBackend (e, info)
+	, PortEngineSharedImpl (e, s_instance_name)
 	, p_stream (0)
 	, p_context (0)
 	, p_mainloop (0)
@@ -590,12 +591,7 @@ PulseAudioBackend::_start (bool /*for_latency_measurement*/)
 		return BackendReinitializationError;
 	}
 
-	if (_ports.size () || _portmap.size ()) {
-		PBD::warning << _("PulseAudioBackend: recovering from unclean shutdown, port registry is not empty.") << endmsg;
-		_system_outputs.clear ();
-		_ports.clear ();
-		_portmap.clear ();
-	}
+	clear_ports ();
 
 	/* reset internal state */
 	_dsp_load                      = 0;
@@ -824,194 +820,6 @@ PulseAudioBackend::my_name () const
 	return _instance_name;
 }
 
-uint32_t
-PulseAudioBackend::port_name_size () const
-{
-	return 256;
-}
-
-int
-PulseAudioBackend::set_port_name (PortEngine::PortHandle port, const std::string& name)
-{
-	std::string newname (_instance_name + ":" + name);
-
-	if (!valid_port (port)) {
-		PBD::error << _("PulseBackend::set_port_name: Invalid Port(s)") << endmsg;
-		return -1;
-	}
-
-	if (find_port (newname)) {
-		PBD::error << _("PulseBackend::set_port_name: Port with given name already exists") << endmsg;
-		return -1;
-	}
-
-	PulsePort* p = static_cast<PulsePort*> (port);
-	_portmap.erase (p->name ());
-	_portmap.insert (make_pair (newname, p));
-	return p->set_name (newname);
-}
-
-std::string
-PulseAudioBackend::get_port_name (PortEngine::PortHandle port) const
-{
-	if (!valid_port (port)) {
-		PBD::error << _("PulseBackend::get_port_name: Invalid Port(s)") << endmsg;
-		return std::string ();
-	}
-	return static_cast<PulsePort*> (port)->name ();
-}
-
-PortFlags
-PulseAudioBackend::get_port_flags (PortEngine::PortHandle port) const
-{
-	if (!valid_port (port)) {
-		PBD::error << _("PulseBackend::get_port_flags: Invalid Port(s)") << endmsg;
-		return PortFlags (0);
-	}
-	return static_cast<PulsePort*> (port)->flags ();
-}
-
-int
-PulseAudioBackend::get_port_property (PortHandle port, const std::string& key, std::string& value, std::string& type) const
-{
-	if (!valid_port (port)) {
-		PBD::warning << _("PulseBackend::get_port_property: Invalid Port(s)") << endmsg;
-		return -1;
-	}
-	if (key == "http://jackaudio.org/metadata/pretty-name") {
-		type  = "";
-		value = static_cast<PulsePort*> (port)->pretty_name ();
-		if (!value.empty ()) {
-			return 0;
-		}
-	}
-	return -1;
-}
-
-int
-PulseAudioBackend::set_port_property (PortHandle port, const std::string& key, const std::string& value, const std::string& type)
-{
-	if (!valid_port (port)) {
-		PBD::warning << _("PulseBackend::set_port_property: Invalid Port(s)") << endmsg;
-		return -1;
-	}
-	if (key == "http://jackaudio.org/metadata/pretty-name" && type.empty ()) {
-		static_cast<PulsePort*> (port)->set_pretty_name (value);
-		return 0;
-	}
-	return -1;
-}
-
-PortEngine::PortHandle
-PulseAudioBackend::get_port_by_name (const std::string& name) const
-{
-	PortHandle port = (PortHandle)find_port (name);
-	return port;
-}
-
-int
-PulseAudioBackend::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) {
-		PulsePort* 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
-PulseAudioBackend::port_data_type (PortEngine::PortHandle port) const
-{
-	if (!valid_port (port)) {
-		return DataType::NIL;
-	}
-	return static_cast<PulsePort*> (port)->type ();
-}
-
-PortEngine::PortHandle
-PulseAudioBackend::register_port (
-    const std::string& name,
-    ARDOUR::DataType   type,
-    ARDOUR::PortFlags  flags)
-{
-	if (name.size () == 0) {
-		return 0;
-	}
-	if (flags & IsPhysical) {
-		return 0;
-	}
-	return add_port (_instance_name + ":" + name, type, flags);
-}
-
-PortEngine::PortHandle
-PulseAudioBackend::add_port (
-    const std::string& name,
-    ARDOUR::DataType   type,
-    ARDOUR::PortFlags  flags)
-{
-	assert (name.size ());
-	if (find_port (name)) {
-		PBD::error << _("PulseBackend::register_port: Port already exists:")
-		           << " (" << name << ")" << endmsg;
-		return 0;
-	}
-	PulsePort* port = NULL;
-	switch (type) {
-		case DataType::AUDIO:
-			port = new PulseAudioPort (*this, name, flags);
-			break;
-		case DataType::MIDI:
-			port = new PulseMidiPort (*this, name, flags);
-			break;
-		default:
-			PBD::error << _("PulseBackend::register_port: Invalid Data Type.") << endmsg;
-			return 0;
-	}
-
-	_ports.insert (port);
-	_portmap.insert (make_pair (name, port));
-
-	return port;
-}
-
-void
-PulseAudioBackend::unregister_port (PortEngine::PortHandle port_handle)
-{
-	if (!_run) {
-		return;
-	}
-	PulsePort*          port = static_cast<PulsePort*> (port_handle);
-	PortIndex::iterator i    = std::find (_ports.begin (), _ports.end (), static_cast<PulsePort*> (port_handle));
-	if (i == _ports.end ()) {
-		PBD::error << _("PulseBackend::unregister_port: Failed to find port") << endmsg;
-		return;
-	}
-	disconnect_all (port_handle);
-	_portmap.erase (port->name ());
-	_ports.erase (i);
-	delete port;
-}
-
 int
 PulseAudioBackend::register_system_ports ()
 {
@@ -1025,7 +833,7 @@ PulseAudioBackend::register_system_ports ()
 		if (!p)
 			return -1;
 		set_latency_range (p, true, lr);
-		PulsePort* ap = static_cast<PulsePort*> (p);
+		BackendPort* ap = static_cast<BackendPort*> (p);
 		//ap->set_pretty_name ("")
 		_system_outputs.push_back (ap);
 	}
@@ -1033,151 +841,33 @@ PulseAudioBackend::register_system_ports ()
 }
 
 void
-PulseAudioBackend::unregister_ports (bool system_only)
-{
-	_system_outputs.clear ();
-
-	for (PortIndex::iterator i = _ports.begin (); i != _ports.end ();) {
-		PortIndex::iterator cur  = i++;
-		PulsePort*          port = *cur;
-		if (!system_only || (port->is_physical () && port->is_terminal ())) {
-			port->disconnect_all ();
-			_portmap.erase (port->name ());
-			delete port;
-			_ports.erase (cur);
-		}
-	}
-}
-
-void
 PulseAudioBackend::update_system_port_latecies ()
 {
-	for (std::vector<PulsePort*>::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);
 	}
 }
 
-int
-PulseAudioBackend::connect (const std::string& src, const std::string& dst)
-{
-	PulsePort* src_port = find_port (src);
-	PulsePort* dst_port = find_port (dst);
-
-	if (!src_port) {
-		PBD::error << _("PulseBackend::connect: Invalid Source port:")
-		           << " (" << src << ")" << endmsg;
-		return -1;
-	}
-	if (!dst_port) {
-		PBD::error << _("PulseBackend::connect: Invalid Destination port:")
-		           << " (" << dst << ")" << endmsg;
-		return -1;
-	}
-	return src_port->connect (dst_port);
-}
-
-int
-PulseAudioBackend::disconnect (const std::string& src, const std::string& dst)
-{
-	PulsePort* src_port = find_port (src);
-	PulsePort* dst_port = find_port (dst);
-
-	if (!src_port || !dst_port) {
-		PBD::error << _("PulseBackend::disconnect: Invalid Port(s)") << endmsg;
-		return -1;
-	}
-	return src_port->disconnect (dst_port);
-}
-
-int
-PulseAudioBackend::connect (PortEngine::PortHandle src, const std::string& dst)
-{
-	PulsePort* dst_port = find_port (dst);
-	if (!valid_port (src)) {
-		PBD::error << _("PulseBackend::connect: Invalid Source Port Handle") << endmsg;
-		return -1;
-	}
-	if (!dst_port) {
-		PBD::error << _("PulseBackend::connect: Invalid Destination Port")
-		           << " (" << dst << ")" << endmsg;
-		return -1;
-	}
-	return static_cast<PulsePort*> (src)->connect (dst_port);
-}
-
-int
-PulseAudioBackend::disconnect (PortEngine::PortHandle src, const std::string& dst)
-{
-	PulsePort* dst_port = find_port (dst);
-	if (!valid_port (src) || !dst_port) {
-		PBD::error << _("PulseBackend::disconnect: Invalid Port(s)") << endmsg;
-		return -1;
-	}
-	return static_cast<PulsePort*> (src)->disconnect (dst_port);
-}
-
-int
-PulseAudioBackend::disconnect_all (PortEngine::PortHandle port)
-{
-	if (!valid_port (port)) {
-		PBD::error << _("PulseBackend::disconnect_all: Invalid Port") << endmsg;
-		return -1;
-	}
-	static_cast<PulsePort*> (port)->disconnect_all ();
-	return 0;
-}
-
-bool
-PulseAudioBackend::connected (PortEngine::PortHandle port, bool /* process_callback_safe*/)
+BackendPort*
+PulseAudioBackend::port_factory (std::string const & name, ARDOUR::DataType type, ARDOUR::PortFlags flags)
 {
-	if (!valid_port (port)) {
-		PBD::error << _("PulseBackend::disconnect_all: Invalid Port") << endmsg;
-		return false;
-	}
-	return static_cast<PulsePort*> (port)->is_connected ();
-}
+	BackendPort* port = 0;
 
-bool
-PulseAudioBackend::connected_to (PortEngine::PortHandle src, const std::string& dst, bool /*process_callback_safe*/)
-{
-	PulsePort* dst_port = find_port (dst);
-#ifndef NDEBUG
-	if (!valid_port (src) || !dst_port) {
-		PBD::error << _("PulseBackend::connected_to: Invalid Port") << endmsg;
-		return false;
+	switch (type) {
+		case DataType::AUDIO:
+			port = new PulseAudioPort (*this, name, flags);
+			break;
+		case DataType::MIDI:
+			port = new PulseMidiPort (*this, name, flags);
+			break;
+		default:
+			PBD::error << string_compose (_("%1::register_port: Invalid Data Type."), _instance_name) << endmsg;
+			return 0;
 	}
-#endif
-	return static_cast<PulsePort*> (src)->is_connected (dst_port);
-}
 
-bool
-PulseAudioBackend::physically_connected (PortEngine::PortHandle port, bool /*process_callback_safe*/)
-{
-	if (!valid_port (port)) {
-		PBD::error << _("PulseBackend::physically_connected: Invalid Port") << endmsg;
-		return false;
-	}
-	return static_cast<PulsePort*> (port)->is_physically_connected ();
+	return port;
 }
 
-int
-PulseAudioBackend::get_connections (PortEngine::PortHandle port, std::vector<std::string>& names, bool /*process_callback_safe*/)
-{
-	if (!valid_port (port)) {
-		PBD::error << _("PulseBackend::get_connections: Invalid Port") << endmsg;
-		return -1;
-	}
-
-	assert (0 == names.size ());
-
-	const std::set<PulsePort*>& connected_ports = static_cast<PulsePort*> (port)->get_connections ();
-
-	for (std::set<PulsePort*>::const_iterator i = connected_ports.begin (); i != connected_ports.end (); ++i) {
-		names.push_back ((*i)->name ());
-	}
-
-	return (int)names.size ();
-}
 
 /* MIDI */
 int
@@ -1261,7 +951,7 @@ PulseAudioBackend::set_latency_range (PortEngine::PortHandle port, bool for_play
 	if (!valid_port (port)) {
 		PBD::error << _("PulsePort::set_latency_range (): invalid port.") << endmsg;
 	}
-	static_cast<PulsePort*> (port)->set_latency_range (latency_range, for_playback);
+	static_cast<BackendPort*> (port)->set_latency_range (latency_range, for_playback);
 }
 
 LatencyRange
@@ -1274,7 +964,7 @@ PulseAudioBackend::get_latency_range (PortEngine::PortHandle port, bool for_play
 		r.max = 0;
 		return r;
 	}
-	PulsePort* p = static_cast<PulsePort*> (port);
+	BackendPort* p = static_cast<BackendPort*> (port);
 	assert (p);
 
 	r = p->latency_range (for_playback);
@@ -1291,93 +981,6 @@ PulseAudioBackend::get_latency_range (PortEngine::PortHandle port, bool for_play
 	return r;
 }
 
-/* Discovering physical ports */
-
-bool
-PulseAudioBackend::port_is_physical (PortEngine::PortHandle port) const
-{
-	if (!valid_port (port)) {
-		PBD::error << _("PulsePort::port_is_physical (): invalid port.") << endmsg;
-		return false;
-	}
-	return static_cast<PulsePort*> (port)->is_physical ();
-}
-
-void
-PulseAudioBackend::get_physical_outputs (DataType type, std::vector<std::string>& port_names)
-{
-	for (PortIndex::iterator i = _ports.begin (); i != _ports.end (); ++i) {
-		PulsePort* port = *i;
-		if ((port->type () == type) && port->is_input () && port->is_physical ()) {
-			port_names.push_back (port->name ());
-		}
-	}
-}
-
-void
-PulseAudioBackend::get_physical_inputs (DataType type, std::vector<std::string>& port_names)
-{
-	for (PortIndex::iterator i = _ports.begin (); i != _ports.end (); ++i) {
-		PulsePort* port = *i;
-		if ((port->type () == type) && port->is_output () && port->is_physical ()) {
-			port_names.push_back (port->name ());
-		}
-	}
-	assert (port_names.size () == 0);
-}
-
-ChanCount
-PulseAudioBackend::n_physical_outputs () const
-{
-	int n_midi  = 0;
-	int n_audio = 0;
-	for (PortIndex::const_iterator i = _ports.begin (); i != _ports.end (); ++i) {
-		PulsePort* 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
-PulseAudioBackend::n_physical_inputs () const
-{
-	int n_midi  = 0;
-	int n_audio = 0;
-	for (PortIndex::const_iterator i = _ports.begin (); i != _ports.end (); ++i) {
-		PulsePort* 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*
@@ -1385,7 +988,7 @@ PulseAudioBackend::get_buffer (PortEngine::PortHandle port, pframes_t nframes)
 {
 	assert (port);
 	assert (valid_port (port));
-	return static_cast<PulsePort*> (port)->get_buffer (nframes);
+	return static_cast<BackendPort*> (port)->get_buffer (nframes);
 }
 
 /* Engine Process */
@@ -1470,7 +1073,7 @@ PulseAudioBackend::main_process_thread ()
 			assert (_system_outputs.size () == N_CHANNELS);
 
 			/* interleave */
-			for (std::vector<PulsePort *>::const_iterator it = _system_outputs.begin (); it != _system_outputs.end (); ++it, ++i) {
+			for (std::vector<BackendPort *>::const_iterator it = _system_outputs.begin (); it != _system_outputs.end (); ++it, ++i) {
 				const float* src = (const float*)(*it)->get_buffer (_samples_per_period);
 				for (size_t n = 0; n < _samples_per_period; ++n) {
 					buf[N_CHANNELS * n + i] = src[n];
@@ -1599,178 +1202,28 @@ descriptor ()
 	return &_descriptor;
 }
 
-/******************************************************************************/
-PulsePort::PulsePort (PulseAudioBackend& b, const std::string& name, PortFlags flags)
-    : _pulse_backend (b)
-    , _name (name)
-    , _flags (flags)
-{
-	_capture_latency_range.min  = 0;
-	_capture_latency_range.max  = 0;
-	_playback_latency_range.min = 0;
-	_playback_latency_range.max = 0;
-	_pulse_backend.port_connect_add_remove_callback (); // XXX -> RT
-}
-
-PulsePort::~PulsePort ()
-{
-	disconnect_all ();
-	_pulse_backend.port_connect_add_remove_callback (); // XXX -> RT
-}
-
-int
-PulsePort::connect (PulsePort* port)
-{
-	if (!port) {
-		PBD::error << _("PulsePort::connect (): invalid (null) port") << endmsg;
-		return -1;
-	}
-
-	if (type () != port->type ()) {
-		PBD::error << _("PulsePort::connect (): wrong port-type") << endmsg;
-		return -1;
-	}
-
-	if (is_output () && port->is_output ()) {
-		PBD::error << _("PulsePort::connect (): cannot inter-connect output ports.") << endmsg;
-		return -1;
-	}
-
-	if (is_input () && port->is_input ()) {
-		PBD::error << _("PulsePort::connect (): cannot inter-connect input ports.") << endmsg;
-		return -1;
-	}
-
-	if (this == port) {
-		PBD::error << _("PulsePort::connect (): cannot self-connect ports.") << endmsg;
-		return -1;
-	}
-
-	if (is_connected (port)) {
-		return -1;
-	}
-
-	_connect (port, true);
-	return 0;
-}
-
-void
-PulsePort::_connect (PulsePort* port, bool callback)
-{
-	_connections.insert (port);
-	if (callback) {
-		port->_connect (this, false);
-		_pulse_backend.port_connect_callback (name (), port->name (), true);
-	}
-}
-
-int
-PulsePort::disconnect (PulsePort* port)
-{
-	if (!port) {
-		PBD::error << _("PulsePort::disconnect (): invalid (null) port") << endmsg;
-		return -1;
-	}
-
-	if (!is_connected (port)) {
-		PBD::error << _("PulsePort::disconnect (): ports are not connected:")
-		           << " (" << name () << ") -> (" << port->name () << ")"
-		           << endmsg;
-		return -1;
-	}
-	_disconnect (port, true);
-	return 0;
-}
-
-void
-PulsePort::_disconnect (PulsePort* port, bool callback)
-{
-	std::set<PulsePort*>::iterator it = _connections.find (port);
-	assert (it != _connections.end ());
-	_connections.erase (it);
-	if (callback) {
-		port->_disconnect (this, false);
-		_pulse_backend.port_connect_callback (name (), port->name (), false);
-	}
-}
-
-void
-PulsePort::disconnect_all ()
-{
-	while (!_connections.empty ()) {
-		std::set<PulsePort*>::iterator it = _connections.begin ();
-		(*it)->_disconnect (this, false);
-		_pulse_backend.port_connect_callback (name (), (*it)->name (), false);
-		_connections.erase (it);
-	}
-}
-
-bool
-PulsePort::is_connected (const PulsePort* port) const
-{
-	return _connections.find (const_cast<PulsePort*> (port)) != _connections.end ();
-}
-
-bool
-PulsePort::is_physically_connected () const
-{
-	for (std::set<PulsePort*>::const_iterator it = _connections.begin (); it != _connections.end (); ++it) {
-		if ((*it)->is_physical ()) {
-			return true;
-		}
-	}
-	return false;
-}
-
-void
-PulsePort::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<PulsePort*>::const_iterator it = _connections.begin (); it != _connections.end (); ++it) {
-		if ((*it)->is_physical ()) {
-			(*it)->update_connected_latency (is_input ());
-		}
-	}
-}
-
-void
-PulsePort::update_connected_latency (bool for_playback)
-{
-	LatencyRange lr;
-	lr.min = lr.max = 0;
-	for (std::set<PulsePort*>::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);
-}
 
 /******************************************************************************/
 
 PulseAudioPort::PulseAudioPort (PulseAudioBackend& b, const std::string& name, PortFlags flags)
-    : PulsePort (b, name, flags)
+    : BackendPort (b, name, flags)
 {
 	memset (_buffer, 0, sizeof (_buffer));
 	mlock (_buffer, sizeof (_buffer));
+	_backend.port_connect_add_remove_callback (); // XXX -> RT
 }
 
 PulseAudioPort::~PulseAudioPort ()
 {
+	_backend.port_connect_add_remove_callback (); // XXX -> RT
 }
 
 void*
 PulseAudioPort::get_buffer (pframes_t n_samples)
 {
 	if (is_input ()) {
-		const std::set<PulsePort*>&          connections = get_connections ();
-		std::set<PulsePort*>::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 {
@@ -1792,14 +1245,16 @@ PulseAudioPort::get_buffer (pframes_t n_samples)
 }
 
 PulseMidiPort::PulseMidiPort (PulseAudioBackend& b, const std::string& name, PortFlags flags)
-    : PulsePort (b, name, flags)
+    : BackendPort (b, name, flags)
 {
 	_buffer.clear ();
 	_buffer.reserve (256);
+	_backend.port_connect_add_remove_callback (); // XXX -> RT
 }
 
 PulseMidiPort::~PulseMidiPort ()
 {
+	_backend.port_connect_add_remove_callback (); // XXX -> RT
 }
 
 struct MidiEventSorter {
@@ -1814,8 +1269,8 @@ void* PulseMidiPort::get_buffer (pframes_t /*n_samples*/)
 {
 	if (is_input ()) {
 		_buffer.clear ();
-		const std::set<PulsePort*>& connections = get_connections ();
-		for (std::set<PulsePort*>::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) {
 			const PulseMidiBuffer* src = static_cast<PulseMidiPort*> (*i)->const_buffer ();
diff --git a/libs/backends/pulseaudio/pulseaudio_backend.h b/libs/backends/pulseaudio/pulseaudio_backend.h
index 51727ff4da..0912b9d961 100644
--- a/libs/backends/pulseaudio/pulseaudio_backend.h
+++ b/libs/backends/pulseaudio/pulseaudio_backend.h
@@ -31,9 +31,11 @@
 
 #include <boost/shared_ptr.hpp>
 
+#include "pbd/natsort.h"
+
 #include "ardour/audio_backend.h"
 #include "ardour/dsp_load_calculator.h"
-#include "pbd/natsort.h"
+#include "ardour/port_engine_shared.h"
 
 #define MaxPulseMidiEventSize (256)
 
@@ -61,67 +63,8 @@ private:
 
 typedef std::vector<boost::shared_ptr<PulseMidiEvent> > PulseMidiBuffer;
 
-class PulsePort
-{
-protected:
-	PulsePort (PulseAudioBackend& b, const std::string&, PortFlags);
-
-public:
-	virtual ~PulsePort ();
-
-	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;
-
-	virtual void* get_buffer (pframes_t nframes) = 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 PulsePort* port) const;
-	bool is_physically_connected () const;
-
-	int connect (PulsePort* port);
-	int disconnect (PulsePort* port);
-	void disconnect_all ();
-
-	const std::set<PulsePort*>&
-	get_connections () const
-	{
-		return _connections;
-	}
-
-	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:
-	PulseAudioBackend&   _pulse_backend;
-	std::string          _name;
-	std::string          _pretty_name;
-	const PortFlags      _flags;
-	LatencyRange         _capture_latency_range;
-	LatencyRange         _playback_latency_range;
-	std::set<PulsePort*> _connections;
-
-	void _connect (PulsePort*, bool);
-	void _disconnect (PulsePort*, bool);
-}; // class PulsePort
-
-class PulseAudioPort : public PulsePort
+class PulseAudioPort : public BackendPort
 {
 public:
 	PulseAudioPort (PulseAudioBackend& b, const std::string&, PortFlags);
@@ -137,7 +80,7 @@ private:
 	Sample _buffer[8192];
 }; // class PulseAudioPort
 
-class PulseMidiPort : public PulsePort
+class PulseMidiPort : public BackendPort
 {
 public:
 	PulseMidiPort (PulseAudioBackend& b, const std::string&, PortFlags);
@@ -152,7 +95,7 @@ private:
 	PulseMidiBuffer _buffer;
 }; // class PulseMidiPort
 
-class PulseAudioBackend : public AudioBackend
+class PulseAudioBackend : public AudioBackend, public PortEngineSharedImpl
 {
 	friend class PulsePort;
 
@@ -241,32 +184,33 @@ public:
 	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;
-
-	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);
+	/* 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 (!_run) 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); }
 
 	/* MIDI */
 	int midi_event_get (pframes_t& timestamp, size_t& size, uint8_t const** buf, void* port_buffer, uint32_t event_index);
@@ -286,14 +230,6 @@ public:
 	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);
@@ -356,25 +292,10 @@ private:
 	};
 
 	/* port engine */
-	PortHandle add_port (const std::string& shortname, ARDOUR::DataType, ARDOUR::PortFlags);
+	BackendPort* port_factory (std::string const & name, ARDOUR::DataType dt, ARDOUR::PortFlags flags);
 	int  register_system_ports ();
-	void unregister_ports (bool system_only = false);
 	void update_system_port_latecies ();
 
-	std::vector<PulsePort*> _system_outputs;
-
-	struct SortByPortName {
-		bool operator() (const PulsePort* lhs, const PulsePort* rhs) const
-		{
-			return PBD::naturally_less (lhs->name ().c_str (), rhs->name ().c_str ());
-		}
-	};
-
-	typedef std::map<std::string, PulsePort*>    PortMap;   // fast lookup in _ports
-	typedef std::set<PulsePort*, SortByPortName> PortIndex; // fast lookup in _ports
-	PortMap   _portmap;
-	PortIndex _ports;
-
 	struct PortConnectData {
 		std::string a;
 		std::string b;
@@ -404,21 +325,6 @@ private:
 		pthread_mutex_unlock (&_port_callback_mutex);
 	}
 
-	bool
-	valid_port (PortHandle port) const
-	{
-		return std::find (_ports.begin (), _ports.end (), static_cast<PulsePort*> (port)) != _ports.end ();
-	}
-
-	PulsePort*
-	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;
-	}
 }; // class PulseAudioBackend
 
 } // namespace