Merge branch 'master' into windows
[ardour.git] / libs / ardour / io.cc
index ba3d70c18461a5a2afbad1587c0aa5d9fe3019ea..1349d49a0ce1c36667c4cff1b57f151ebd188778 100644 (file)
@@ -1,5 +1,5 @@
 /*
-    Copyright (C) 2000-2006 Paul Davis 
+    Copyright (C) 2000-2006 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
 
 #include <fstream>
 #include <algorithm>
+#include <cmath>
+
 #include <unistd.h>
 #include <locale.h>
 #include <errno.h>
 
-#include <sigc++/bind.h>
-
 #include <glibmm.h>
-#include <glibmm/thread.h>
+#include <glibmm/threads.h>
 
 #include "pbd/xml++.h"
 #include "pbd/replace_all.h"
 #include "pbd/unknown_type.h"
+#include "pbd/enumwriter.h"
 
 #include "ardour/audioengine.h"
+#include "ardour/buffer.h"
+#include "ardour/buffer_set.h"
+#include "ardour/debug.h"
 #include "ardour/io.h"
-#include "ardour/route.h"
 #include "ardour/port.h"
-#include "ardour/audio_port.h"
-#include "ardour/midi_port.h"
+#include "ardour/route.h"
 #include "ardour/session.h"
-#include "ardour/cycle_timer.h"
-#include "ardour/panner.h"
-#include "ardour/buffer_set.h"
-#include "ardour/meter.h"
-#include "ardour/amp.h"
 #include "ardour/user_bundle.h"
 
 #include "i18n.h"
 
-#include <cmath>
-
-/*
-  A bug in OS X's cmath that causes isnan() and isinf() to be 
-  "undeclared". the following works around that
-*/
-
-#if defined(__APPLE__) && defined(__MACH__)
-extern "C" int isnan (double);
-extern "C" int isinf (double);
-#endif
-
-#define BLOCK_PROCESS_CALLBACK() Glib::Mutex::Lock em (_session.engine().process_lock())
+#define BLOCK_PROCESS_CALLBACK() Glib::Threads::Mutex::Lock em (AudioEngine::instance()->process_lock())
 
 using namespace std;
 using namespace ARDOUR;
@@ -67,275 +52,109 @@ using namespace PBD;
 
 const string                 IO::state_node_name = "IO";
 bool                         IO::connecting_legal = false;
-bool                         IO::ports_legal = false;
-bool                         IO::panners_legal = false;
-sigc::signal<void>           IO::Meter;
-sigc::signal<int>            IO::ConnectingLegal;
-sigc::signal<int>            IO::PortsLegal;
-sigc::signal<int>            IO::PannersLegal;
-sigc::signal<void,ChanCount> IO::PortCountChanged;
-sigc::signal<void,nframes_t> IO::CycleStart;
-
-Glib::StaticMutex IO::m_meter_signal_lock = GLIBMM_STATIC_MUTEX_INIT;
-
-/* this is a default mapper of [0 .. 1.0] control values to a gain coefficient.
-   others can be imagined. 
-*/
-
-#if 0
-static gain_t direct_control_to_gain (double fract) { 
-       /* XXX Marcus writes: this doesn't seem right to me. but i don't have a better answer ... */
-       /* this maxes at +6dB */
-       return pow (2.0,(sqrt(sqrt(sqrt(fract)))*198.0-192.0)/6.0);
-}
-
-static double direct_gain_to_control (gain_t gain) { 
-       /* XXX Marcus writes: this doesn't seem right to me. but i don't have a better answer ... */
-       if (gain == 0) return 0.0;
-       
-       return pow((6.0*log(gain)/log(2.0)+192.0)/198.0, 8.0);
-}
-#endif
+PBD::Signal0<int>            IO::ConnectingLegal;
+PBD::Signal1<void,ChanCount> IO::PortCountChanged;
 
 /** @param default_type The type of port that will be created by ensure_io
  * and friends if no type is explicitly requested (to avoid breakage).
  */
-IO::IO (Session& s, const string& name, DataType default_type)
+IO::IO (Session& s, const string& name, Direction dir, DataType default_type, bool sendish)
        : SessionObject (s, name)
-       , AutomatableControls (s)
-       , _output_buffers (new BufferSet())
-       , _active (true)
+       , _direction (dir)
        , _default_type (default_type)
-       , _amp (new Amp(s, *this))
-       , _meter (new PeakMeter(s))
-       , _panner (new Panner(name, s))
+       , _sendish (sendish)
 {
-       _gain = 1.0;
+       _active = true;
+       Port::PostDisconnect.connect_same_thread (*this, boost::bind (&IO::disconnect_check, this, _1, _2));
        pending_state_node = 0;
-       no_panner_reset = false;
-       _phase_invert = false;
-       deferred_state = 0;
-
-       boost::shared_ptr<AutomationList> gl(
-                       new AutomationList(Evoral::Parameter(GainAutomation)));
-
-       _gain_control = boost::shared_ptr<GainControl>( new GainControl( X_("gaincontrol"), this, Evoral::Parameter(GainAutomation), gl ));
-
-       add_control(_gain_control);
-       
-       {
-               // IO::Meter is emitted from another thread so the
-               // Meter signal must be protected.
-               Glib::Mutex::Lock guard (m_meter_signal_lock);
-               m_meter_connection = Meter.connect (mem_fun (*this, &IO::meter));
-       }
-       
-       _output_offset = 0;
-       CycleStart.connect (mem_fun (*this, &IO::cycle_start));
-
-       _session.add_controllable (_gain_control);
-
-       setup_bundles_for_inputs_and_outputs ();
+       setup_bundle ();
 }
 
-IO::IO (Session& s, const XMLNode& node, DataType dt)
+IO::IO (Session& s, const XMLNode& node, DataType dt, bool sendish)
        : SessionObject(s, "unnamed io")
-       , AutomatableControls (s)
-       , _output_buffers (new BufferSet())
-       , _active(true)
+       , _direction (Input)
        , _default_type (dt)
-       , _amp (new Amp(s, *this))
-       , _meter(new PeakMeter (_session))
+       , _sendish (sendish)
 {
-       deferred_state = 0;
-       no_panner_reset = false;
-       _gain = 1.0;
-
-       boost::shared_ptr<AutomationList> gl(
-                       new AutomationList(Evoral::Parameter(GainAutomation)));
-
-       _gain_control = boost::shared_ptr<GainControl>(
-                       new GainControl( X_("gaincontrol"), this, Evoral::Parameter(GainAutomation), gl));
-
-       add_control(_gain_control);
-
-       set_state (node);
-
-       {
-               // IO::Meter is emitted from another thread so the
-               // Meter signal must be protected.
-               Glib::Mutex::Lock guard (m_meter_signal_lock);
-               m_meter_connection = Meter.connect (mem_fun (*this, &IO::meter));
-       }
-       
-       _output_offset = 0;
-       CycleStart.connect (mem_fun (*this, &IO::cycle_start));
-
-       _session.add_controllable (_gain_control);
+       _active = true;
+       pending_state_node = 0;
+       Port::PostDisconnect.connect_same_thread (*this, boost::bind (&IO::disconnect_check, this, _1, _2));
 
-       setup_bundles_for_inputs_and_outputs ();
+       set_state (node, Stateful::loading_state_version);
+       setup_bundle ();
 }
 
 IO::~IO ()
 {
-       Glib::Mutex::Lock guard (m_meter_signal_lock);
-       Glib::Mutex::Lock lm (io_lock);
+       Glib::Threads::Mutex::Lock lm (io_lock);
 
        BLOCK_PROCESS_CALLBACK ();
 
-       for (PortSet::iterator i = _inputs.begin(); i != _inputs.end(); ++i) {
+       for (PortSet::iterator i = _ports.begin(); i != _ports.end(); ++i) {
                _session.engine().unregister_port (*i);
        }
-
-       for (PortSet::iterator i = _outputs.begin(); i != _outputs.end(); ++i) {
-               _session.engine().unregister_port (*i);
-       }
-
-       m_meter_connection.disconnect();
-}
-
-void
-IO::silence (nframes_t nframes)
-{
-       /* io_lock, not taken: function must be called from Session::process() calltree */
-
-       for (PortSet::iterator i = _outputs.begin(); i != _outputs.end(); ++i) {
-               i->get_buffer(nframes).silence (nframes);
-       }
 }
 
-/** Deliver bufs to the IO's output ports
- *
- * This function should automatically do whatever it necessary to correctly deliver bufs
- * to the outputs, eg applying gain or pan or whatever else needs to be done.
- */
 void
-IO::deliver_output (BufferSet& bufs, sframes_t start_frame, sframes_t end_frame, nframes_t nframes)
+IO::disconnect_check (boost::shared_ptr<Port> a, boost::shared_ptr<Port> b)
 {
-       // Attach output buffers to port buffers
-       output_buffers().attach_buffers (_outputs, nframes, _output_offset);
-
-       // Use the panner to distribute audio to output port buffers
-       if (_panner && _panner->npanners() && !_panner->bypassed()) {
-
-               _panner->run_out_of_place(bufs, output_buffers(), start_frame, end_frame, nframes);
-
-       // Do a 1:1 copy of data to output ports
-       } else {
-               if (bufs.count().n_audio() > 0 && _outputs.count().n_audio () > 0) {
-                       copy_to_outputs (bufs, DataType::AUDIO, nframes);
-               }
-               if (bufs.count().n_midi() > 0 && _outputs.count().n_midi () > 0) {
-                       copy_to_outputs (bufs, DataType::MIDI, nframes);
-               }
-       }
-       
-       // Apply gain to output buffers if gain automation isn't playing
-       if ( ! _amp->apply_gain_automation()) {
-               
-               gain_t dg = _gain; // desired gain
-
-               {
-                       Glib::Mutex::Lock dm (declick_lock, Glib::TRY_LOCK);
-
-                       if (dm.locked()) {
-                               dg = _gain_control->user_float();
-                       }
+       /* this could be called from within our own ::disconnect() method(s)
+          or from somewhere that operates directly on a port. so, we don't
+          know for sure if we can take this lock or not. if we fail,
+          we assume that its safely locked by our own ::disconnect().
+       */
 
-               }
+       Glib::Threads::Mutex::Lock tm (io_lock, Glib::Threads::TRY_LOCK);
 
-               if (dg != _gain || dg != 1.0) {
-                       Amp::apply_gain(output_buffers(), nframes, _gain, dg, _phase_invert);
-                       _gain = dg;
+       if (tm.locked()) {
+               /* we took the lock, so we cannot be here from inside
+                * ::disconnect()
+                */
+               if (_ports.contains (a) || _ports.contains (b)) {
+                       changed (IOChange (IOChange::ConnectionsChanged), this); /* EMIT SIGNAL */              
                }
+       } else {
+               /* we didn't get the lock, so assume that we're inside
+                * ::disconnect(), and it will call changed() appropriately.
+                */
        }
-       
 }
 
 void
-IO::copy_to_outputs (BufferSet& bufs, DataType type, nframes_t nframes)
+IO::increment_port_buffer_offset (pframes_t offset)
 {
-       // Copy any buffers 1:1 to outputs
-       
-       PortSet::iterator o = _outputs.begin(type);
-       BufferSet::iterator i = bufs.begin(type);
-       BufferSet::iterator prev = i;
+       /* io_lock, not taken: function must be called from Session::process() calltree */
 
-       while (i != bufs.end(type) && o != _outputs.end (type)) {
-               Buffer& port_buffer (o->get_buffer (nframes));
-               port_buffer.read_from (*i, nframes, _output_offset);
-               prev = i;
-               ++i;
-               ++o;
-       }
-       
-       // Copy last buffer to any extra outputs
-       while (o != _outputs.end(type)) {
-               Buffer& port_buffer (o->get_buffer (nframes));
-               port_buffer.read_from (*prev, nframes, _output_offset);
-               ++o;
-       }
+        if (_direction == Output) {
+                for (PortSet::iterator i = _ports.begin(); i != _ports.end(); ++i) {
+                        i->increment_port_buffer_offset (offset);
+                }
+        }
 }
 
 void
-IO::collect_input (BufferSet& outs, nframes_t nframes, ChanCount offset)
+IO::silence (framecnt_t nframes)
 {
-       assert(outs.available() >= n_inputs());
-       
-       if (n_inputs() == ChanCount::ZERO) {
-               return;
-       }
-
-       outs.set_count(n_inputs());
-
-       for (DataType::iterator t = DataType::begin(); t != DataType::end(); ++t) {
-               PortSet::iterator   i = _inputs.begin(*t);
-               BufferSet::iterator o = outs.begin(*t);
-
-               for (uint32_t off = 0; off < offset.get(*t); ++off, ++o) {
-                       if (o == outs.end(*t)) {
-                               continue;
-                       }
-               }
+       /* io_lock, not taken: function must be called from Session::process() calltree */
 
-               for ( ; i != _inputs.end(*t); ++i, ++o) {
-                       Buffer& b (i->get_buffer (nframes));
-                       o->read_from (b, nframes);
-               }
+       for (PortSet::iterator i = _ports.begin(); i != _ports.end(); ++i) {
+               i->get_buffer(nframes).silence (nframes);
        }
 }
 
+/** Set _bundles_connected to those bundles that are connected such that every
+ *  port on every bundle channel x is connected to port x in _ports.
+ */
 void
-IO::just_meter_input (sframes_t start_frame, sframes_t end_frame, nframes_t nframes)
-{
-       BufferSet& bufs = _session.get_scratch_buffers (n_inputs());
-       collect_input (bufs, nframes);
-       _meter->run_in_place (bufs, start_frame, end_frame, nframes);
-}
-
-
-void
-IO::check_bundles_connected_to_inputs ()
-{
-       check_bundles (_bundles_connected_to_inputs, inputs());
-}
-
-void
-IO::check_bundles_connected_to_outputs ()
+IO::check_bundles_connected ()
 {
-       check_bundles (_bundles_connected_to_outputs, outputs());
-}
+       std::vector<UserBundleInfo*> new_list;
 
-void
-IO::check_bundles (std::vector<UserBundleInfo>& list, const PortSet& ports)
-{
-       std::vector<UserBundleInfo> new_list;
-       
-       for (std::vector<UserBundleInfo>::iterator i = list.begin(); i != list.end(); ++i) {
+       for (std::vector<UserBundleInfo*>::iterator i = _bundles_connected.begin(); i != _bundles_connected.end(); ++i) {
 
-               uint32_t const N = i->bundle->nchannels ();
+               uint32_t const N = (*i)->bundle->nchannels().n_total();
 
-               if (ports.num_ports (default_type()) < N) {
+               if (_ports.num_ports() < N) {
                        continue;
                }
 
@@ -343,9 +162,9 @@ IO::check_bundles (std::vector<UserBundleInfo>& list, const PortSet& ports)
 
                for (uint32_t j = 0; j < N; ++j) {
                        /* Every port on bundle channel j must be connected to our input j */
-                       Bundle::PortList const pl = i->bundle->channel_ports (j);
+                       Bundle::PortList const pl = (*i)->bundle->channel_ports (j);
                        for (uint32_t k = 0; k < pl.size(); ++k) {
-                               if (ports.port(j)->connected_to (pl[k]) == false) {
+                               if (_ports.port(j)->connected_to (pl[k]) == false) {
                                        ok = false;
                                        break;
                                }
@@ -359,763 +178,348 @@ IO::check_bundles (std::vector<UserBundleInfo>& list, const PortSet& ports)
                if (ok) {
                        new_list.push_back (*i);
                } else {
-                       i->changed.disconnect ();
+                       delete *i;
                }
        }
 
-       list = new_list;
+       _bundles_connected = new_list;
 }
 
 
 int
-IO::disconnect_input (Port* our_port, string other_port, void* src)
+IO::disconnect (boost::shared_ptr<Port> our_port, string other_port, void* src)
 {
        if (other_port.length() == 0 || our_port == 0) {
                return 0;
        }
 
-       { 
-               BLOCK_PROCESS_CALLBACK ();
-               
-               {
-                       Glib::Mutex::Lock lm (io_lock);
-                       
-                       /* check that our_port is really one of ours */
-                       
-                       if ( ! _inputs.contains(our_port)) {
-                               return -1;
-                       }
-                       
-                       /* disconnect it from the source */
-                       
-                       if (our_port->disconnect (other_port)) {
-                               error << string_compose(_("IO: cannot disconnect input port %1 from %2"), our_port->name(), other_port) << endmsg;
-                               return -1;
-                       }
+        {
+                Glib::Threads::Mutex::Lock lm (io_lock);
 
-                       check_bundles_connected_to_inputs ();
-               }
-       }
+                /* check that our_port is really one of ours */
 
-       input_changed (ConnectionsChanged, src); /* EMIT SIGNAL */
-       _session.set_dirty ();
+                if ( ! _ports.contains(our_port)) {
+                        return -1;
+                }
 
-       return 0;
-}
+                /* disconnect it from the source */
 
-int
-IO::connect_input (Port* our_port, string other_port, void* src)
-{
-       if (other_port.length() == 0 || our_port == 0) {
-               return 0;
-       }
+                if (our_port->disconnect (other_port)) {
+                        error << string_compose(_("IO: cannot disconnect port %1 from %2"), our_port->name(), other_port) << endmsg;
+                        return -1;
+                }
 
-       {
-               BLOCK_PROCESS_CALLBACK ();
-               
-               {
-                       Glib::Mutex::Lock lm (io_lock);
-                       
-                       /* check that our_port is really one of ours */
-                       
-                       if ( ! _inputs.contains(our_port) ) {
-                               return -1;
-                       }
-                       
-                       /* connect it to the source */
+                check_bundles_connected ();
+        }
 
-                       if (our_port->connect (other_port)) {
-                               return -1;
-                       }
-               }
-       }
+        changed (IOChange (IOChange::ConnectionsChanged), src); /* EMIT SIGNAL */
 
-       input_changed (ConnectionsChanged, src); /* EMIT SIGNAL */
        _session.set_dirty ();
+
        return 0;
 }
 
 int
-IO::disconnect_output (Port* our_port, string other_port, void* src)
+IO::connect (boost::shared_ptr<Port> our_port, string other_port, void* src)
 {
        if (other_port.length() == 0 || our_port == 0) {
                return 0;
        }
 
        {
-               BLOCK_PROCESS_CALLBACK ();
-               
-               {
-                       Glib::Mutex::Lock lm (io_lock);
-                       
-                       /* check that our_port is really one of ours */
-                       
-                       if ( ! _outputs.contains(our_port) ) {
-                               return -1;
-                       }
-                       
-                       /* disconnect it from the destination */
-                       
-                       if (our_port->disconnect (other_port)) {
-                               error << string_compose(_("IO: cannot disconnect output port %1 from %2"), our_port->name(), other_port) << endmsg;
-                               return -1;
-                       }
-
-                       check_bundles_connected_to_outputs ();
-               }
-       }
+               Glib::Threads::Mutex::Lock lm (io_lock);
 
-       output_changed (ConnectionsChanged, src); /* EMIT SIGNAL */
-       _session.set_dirty ();
-       return 0;
-}
+               /* check that our_port is really one of ours */
 
-int
-IO::connect_output (Port* our_port, string other_port, void* src)
-{
-       if (other_port.length() == 0 || our_port == 0) {
-               return 0;
-       }
+               if ( ! _ports.contains(our_port) ) {
+                       return -1;
+               }
 
-       {
-               BLOCK_PROCESS_CALLBACK ();
+               /* connect it to the source */
 
-               
-               {
-                       Glib::Mutex::Lock lm (io_lock);
-                       
-                       /* check that our_port is really one of ours */
-                       
-                       if ( ! _outputs.contains(our_port) ) {
-                               return -1;
-                       }
-                       
-                       /* connect it to the destination */
-                       
-                       if (our_port->connect (other_port)) {
-                               return -1;
-                       }
+               if (our_port->connect (other_port)) {
+                       return -1;
                }
        }
-
-       output_changed (ConnectionsChanged, src); /* EMIT SIGNAL */
+       changed (IOChange (IOChange::ConnectionsChanged), src); /* EMIT SIGNAL */
        _session.set_dirty ();
        return 0;
 }
 
 int
-IO::set_input (Port* other_port, void* src)
+IO::remove_port (boost::shared_ptr<Port> port, void* src)
 {
-       /* this removes all but one ports, and connects that one port
-          to the specified source.
-       */
-
-       if (!other_port) {
-               return -1;
-       }
+       ChanCount before = _ports.count ();
+       ChanCount after = before;
+       after.set (port->type(), after.get (port->type()) - 1);
 
-       if (ensure_inputs (ChanCount(other_port->type(), 1), true, true, src)) {
+       boost::optional<bool> const r = PortCountChanging (after); /* EMIT SIGNAL */
+       if (r.get_value_or (false)) {
                return -1;
        }
 
-       return connect_input (_inputs.port(0), other_port->name(), src);
-}
-
-int
-IO::remove_output_port (Port* port, void* src)
-{
-       IOChange change (NoChange);
+       IOChange change;
 
        {
                BLOCK_PROCESS_CALLBACK ();
 
-               
                {
-                       Glib::Mutex::Lock lm (io_lock);
+                       Glib::Threads::Mutex::Lock lm (io_lock);
 
-                       if (_outputs.remove(port)) {
-                               change = IOChange (change|ConfigurationChanged);
+                       if (_ports.remove(port)) {
+                               change.type = IOChange::Type (change.type | IOChange::ConfigurationChanged);
+                               change.before = before;
+                               change.after = _ports.count ();
 
                                if (port->connected()) {
-                                       change = IOChange (change|ConnectionsChanged);
-                               } 
-
-                               _session.engine().unregister_port (*port);
-                               check_bundles_connected_to_outputs ();
-                               
-                               setup_peak_meters ();
-                               reset_panner ();
+                                       change.type = IOChange::Type (change.type | IOChange::ConnectionsChanged);
+                               }
+
+                               _session.engine().unregister_port (port);
+                               check_bundles_connected ();
                        }
                }
 
-               PortCountChanged (n_outputs()); /* EMIT SIGNAL */
+               PortCountChanged (n_ports()); /* EMIT SIGNAL */
+
+               if (change.type != IOChange::NoChange) {
+                       changed (change, src);
+                       _buffers.attach_buffers (_ports);
+               }
        }
 
-       if (change == ConfigurationChanged) {
-               setup_bundle_for_outputs ();
+       if (change.type & IOChange::ConfigurationChanged) {
+               setup_bundle ();
        }
 
-       if (change != NoChange) {
-               output_changed (change, src);
-               _session.set_dirty ();
-               return 0;
+       if (change.type == IOChange::NoChange) {
+               return -1;
        }
 
-       return -1;
+       _session.set_dirty ();
+       
+       return 0;
 }
 
-/** Add an output port.
+/** Add a port.
  *
- * @param destination Name of input port to connect new port to.
+ * @param destination Name of port to connect new port to.
  * @param src Source for emitted ConfigurationChanged signal.
  * @param type Data type of port.  Default value (NIL) will use this IO's default type.
  */
 int
-IO::add_output_port (string destination, void* src, DataType type)
+IO::add_port (string destination, void* src, DataType type)
 {
-       Port* our_port;
+       boost::shared_ptr<Port> our_port;
 
-       if (type == DataType::NIL)
+       if (type == DataType::NIL) {
                type = _default_type;
+       }
+
+       ChanCount before = _ports.count ();
+       ChanCount after = before;
+       after.set (type, after.get (type) + 1);
+       
+       bool const r = PortCountChanging (after); /* EMIT SIGNAL */
+       if (r) {
+               return -1;
+       }
+       
+       IOChange change;
 
        {
                BLOCK_PROCESS_CALLBACK ();
 
-               
-               { 
-                       Glib::Mutex::Lock lm (io_lock);
-                       
-                       /* Create a new output port */
-                       
-                       string portname = build_legal_port_name (type, false);
+
+               {
+                       Glib::Threads::Mutex::Lock lm (io_lock);
+
+                       /* Create a new port */
+
+                       string portname = build_legal_port_name (type);
                        
-                       if ((our_port = _session.engine().register_output_port (type, portname)) == 0) {
-                               error << string_compose(_("IO: cannot register output port %1"), portname) << endmsg;
-                               return -1;
+                       if (_direction == Input) {
+                               if ((our_port = _session.engine().register_input_port (type, portname)) == 0) {
+                                       error << string_compose(_("IO: cannot register input port %1"), portname) << endmsg;
+                                       return -1;
+                               }
+                       } else {
+                               if ((our_port = _session.engine().register_output_port (type, portname)) == 0) {
+                                       error << string_compose(_("IO: cannot register output port %1"), portname) << endmsg;
+                                       return -1;
+                               }
                        }
-                       
-                       _outputs.add (our_port);
-                       setup_peak_meters ();
-                       reset_panner ();
-               }
 
-               PortCountChanged (n_outputs()); /* EMIT SIGNAL */
+                       change.before = _ports.count ();
+                       _ports.add (our_port);
+               }
+               
+               PortCountChanged (n_ports()); /* EMIT SIGNAL */
+               change.type = IOChange::ConfigurationChanged;
+               change.after = _ports.count ();
+               changed (change, src); /* EMIT SIGNAL */
+               _buffers.attach_buffers (_ports);
        }
 
-       if (destination.length()) {
+       if (!destination.empty()) {
                if (our_port->connect (destination)) {
                        return -1;
                }
        }
-       
-       // pan_changed (src); /* EMIT SIGNAL */
-       output_changed (ConfigurationChanged, src); /* EMIT SIGNAL */
-       setup_bundle_for_outputs ();
+
+       setup_bundle ();
        _session.set_dirty ();
 
        return 0;
 }
 
 int
-IO::remove_input_port (Port* port, void* src)
+IO::disconnect (void* src)
 {
-       IOChange change (NoChange);
-
        {
-               BLOCK_PROCESS_CALLBACK ();
-
-               
-               {
-                       Glib::Mutex::Lock lm (io_lock);
+               Glib::Threads::Mutex::Lock lm (io_lock);
 
-                       if (_inputs.remove(port)) {
-                               change = IOChange (change|ConfigurationChanged);
-
-                               if (port->connected()) {
-                                       change = IOChange (change|ConnectionsChanged);
-                               } 
-
-                               _session.engine().unregister_port (*port);
-                               check_bundles_connected_to_inputs ();
-                               
-                               setup_peak_meters ();
-                               reset_panner ();
-                       }
+               for (PortSet::iterator i = _ports.begin(); i != _ports.end(); ++i) {
+                       i->disconnect_all ();
                }
-               
-               PortCountChanged (n_inputs ()); /* EMIT SIGNAL */
-       }
 
-       if (change == ConfigurationChanged) {
-               setup_bundle_for_inputs ();
+               check_bundles_connected ();
        }
 
-       if (change != NoChange) {
-               input_changed (change, src);
-               _session.set_dirty ();
-               return 0;
-       } 
-       
-       return -1;
-}
+       changed (IOChange (IOChange::ConnectionsChanged), src); /* EMIT SIGNAL */
 
+       return 0;
+}
 
-/** Add an input port.
- *
- * @param type Data type of port.  The appropriate port type, and @ref Port will be created.
- * @param destination Name of input port to connect new port to.
- * @param src Source for emitted ConfigurationChanged signal.
- */
+/** Caller must hold process lock */
 int
-IO::add_input_port (string source, void* src, DataType type)
+IO::ensure_ports_locked (ChanCount count, bool clear, bool& changed)
 {
-       Port* our_port;
-       
-       if (type == DataType::NIL)
-               type = _default_type;
+#ifndef WIN32
+       assert (!AudioEngine::instance()->process_lock().trylock());
+#endif
 
-       {
-               BLOCK_PROCESS_CALLBACK ();
-               
-               { 
-                       Glib::Mutex::Lock lm (io_lock);
-
-                       /* Create a new input port */
-                       
-                       string portname = build_legal_port_name (type, true);
-
-                       if ((our_port = _session.engine().register_input_port (type, portname)) == 0) {
-                               error << string_compose(_("IO: cannot register input port %1"), portname) << endmsg;
-                               return -1;
-                       }
+       boost::shared_ptr<Port> port;
 
-                       _inputs.add (our_port);
-                       setup_peak_meters ();
-                       reset_panner ();
-               }
+       changed    = false;
 
-               PortCountChanged (n_inputs()); /* EMIT SIGNAL */
-       }
-
-       if (source.length()) {
-
-               if (our_port->connect (source)) {
-                       return -1;
-               }
-       } 
-
-       // pan_changed (src); /* EMIT SIGNAL */
-       input_changed (ConfigurationChanged, src); /* EMIT SIGNAL */
-       setup_bundle_for_inputs ();
-       _session.set_dirty ();
-       
-       return 0;
-}
-
-int
-IO::disconnect_inputs (void* src)
-{
-       { 
-               BLOCK_PROCESS_CALLBACK ();
-               
-               {
-                       Glib::Mutex::Lock lm (io_lock);
-                       
-                       for (PortSet::iterator i = _inputs.begin(); i != _inputs.end(); ++i) {
-                               i->disconnect_all ();
-                       }
-
-                       check_bundles_connected_to_inputs ();
-               }
-       }
-       
-       input_changed (ConnectionsChanged, src); /* EMIT SIGNAL */
-       
-       return 0;
-}
-
-int
-IO::disconnect_outputs (void* src)
-{
-       {
-               BLOCK_PROCESS_CALLBACK ();
-               
-               {
-                       Glib::Mutex::Lock lm (io_lock);
-                       
-                       for (PortSet::iterator i = _outputs.begin(); i != _outputs.end(); ++i) {
-                               i->disconnect_all ();
-                       }
-
-                       check_bundles_connected_to_outputs ();
-               }
-       }
-
-       output_changed (ConnectionsChanged, src); /* EMIT SIGNAL */
-       _session.set_dirty ();
-       
-       return 0;
-}
-
-bool
-IO::ensure_inputs_locked (ChanCount count, bool clear, void* src)
-{
-       Port* input_port = 0;
-       bool  changed    = false;
-       
        for (DataType::iterator t = DataType::begin(); t != DataType::end(); ++t) {
-               
+
                const size_t n = count.get(*t);
-       
+
                /* remove unused ports */
-               for (size_t i = n_inputs().get(*t); i > n; --i) {
-                       input_port = _inputs.port(*t, i-1);
+               for (size_t i = n_ports().get(*t); i > n; --i) {
+                       port = _ports.port(*t, i-1);
 
-                       assert(input_port);
-                       _inputs.remove(input_port);
-                       _session.engine().unregister_port (*input_port);
+                       assert(port);
+                       _ports.remove(port);
+                       _session.engine().unregister_port (port);
 
                        changed = true;
                }
 
                /* create any necessary new ports */
-               while (n_inputs().get(*t) < n) {
+               while (n_ports().get(*t) < n) {
 
-                       string portname = build_legal_port_name (*t, true);
+                       string portname = build_legal_port_name (*t);
 
                        try {
 
-                               if ((input_port = _session.engine().register_input_port (*t, portname)) == 0) {
-                                       error << string_compose(_("IO: cannot register input port %1"), portname) << endmsg;
-                                       return -1;
-                               }
-                       }
-
-                       catch (AudioEngine::PortRegistrationFailure& err) {
-                               setup_peak_meters ();
-                               reset_panner ();
-                               /* pass it on */
-                               throw AudioEngine::PortRegistrationFailure();
-                       }
-
-                       _inputs.add (input_port);
-                       changed = true;
-               }
-       }
-       
-       if (changed) {
-               check_bundles_connected_to_inputs ();
-               setup_peak_meters ();
-               reset_panner ();
-               PortCountChanged (n_inputs()); /* EMIT SIGNAL */
-               _session.set_dirty ();
-       }
-       
-       if (clear) {
-               /* disconnect all existing ports so that we get a fresh start */
-               for (PortSet::iterator i = _inputs.begin(); i != _inputs.end(); ++i) {
-                       i->disconnect_all ();
-               }
-       }
-
-       return changed;
-}
-
-int
-IO::ensure_io (ChanCount in, ChanCount out, bool clear, void* src)
-{
-       bool in_changed     = false;
-       bool out_changed    = false;
-
-       assert(in != ChanCount::INFINITE);
-       assert(out != ChanCount::INFINITE);
-
-       if (in == n_inputs() && out == n_outputs() && !clear) {
-               return 0;
-       }
-
-       {
-               BLOCK_PROCESS_CALLBACK ();
-               Glib::Mutex::Lock lm (io_lock);
-
-               Port* port;
-               
-               for (DataType::iterator t = DataType::begin(); t != DataType::end(); ++t) {
-
-                       const size_t nin = in.get(*t);
-                       const size_t nout = out.get(*t);
-
-                       Port* output_port = 0;
-                       Port* input_port = 0;
-
-                       /* remove unused output ports */
-                       for (size_t i = n_outputs().get(*t); i > nout; --i) {
-                               output_port = _outputs.port(*t, i-1);
-
-                               assert(output_port);
-                               _outputs.remove(output_port);
-                               _session.engine().unregister_port (*output_port);
-
-                               out_changed = true;
-                       }
-
-                       /* remove unused input ports */
-                       for (size_t i = n_inputs().get(*t); i > nin; --i) {
-                               input_port = _inputs.port(*t, i-1);
-
-                               assert(input_port);
-                               _inputs.remove(input_port);
-                               _session.engine().unregister_port (*input_port);
-
-                               in_changed = true;
-                       }
-
-                       /* create any necessary new input ports */
-                       while (n_inputs().get(*t) < nin) {
-                               string portname = build_legal_port_name (*t, true);
-
-                               try {
+                               if (_direction == Input) {
                                        if ((port = _session.engine().register_input_port (*t, portname)) == 0) {
                                                error << string_compose(_("IO: cannot register input port %1"), portname) << endmsg;
                                                return -1;
                                        }
-                               }
-                               
-                               catch (AudioEngine::PortRegistrationFailure& err) {
-                                       setup_peak_meters ();
-                                       reset_panner ();
-                                       /* pass it on */
-                                       throw err;
-                               }
-
-                               _inputs.add (port);
-                               in_changed = true;
-                       }
-
-                       /* create any necessary new output ports */
-
-                       while (n_outputs().get(*t) < nout) {
-
-                               string portname = build_legal_port_name (*t, false);
-                               
-                               try { 
+                               } else {
                                        if ((port = _session.engine().register_output_port (*t, portname)) == 0) {
                                                error << string_compose(_("IO: cannot register output port %1"), portname) << endmsg;
                                                return -1;
                                        }
                                }
-
-                               catch (AudioEngine::PortRegistrationFailure& err) {
-                                       setup_peak_meters ();
-                                       reset_panner ();
-                                       /* pass it on */
-                                       throw err;
-                               }
-
-                               _outputs.add (port);
-                               out_changed = true;
                        }
-               }
-               
-               if (clear) {
-                       
-                       /* disconnect all existing ports so that we get a fresh start */
-                       
-                       for (PortSet::iterator i = _inputs.begin(); i != _inputs.end(); ++i) {
-                               i->disconnect_all ();
-                       }
-                       
-                       for (PortSet::iterator i = _outputs.begin(); i != _outputs.end(); ++i) {
-                               i->disconnect_all ();
-                       }
-               }
-               
-               if (in_changed || out_changed) {
-                       setup_peak_meters ();
-                       reset_panner ();
-               }
-       }
-
-       if (out_changed) {
-               check_bundles_connected_to_outputs ();
-               output_changed (ConfigurationChanged, src); /* EMIT SIGNAL */
-               setup_bundle_for_outputs ();
-       }
-       
-       if (in_changed) {
-               check_bundles_connected_to_inputs ();
-               input_changed (ConfigurationChanged, src); /* EMIT SIGNAL */
-               setup_bundle_for_inputs ();
-       }
-
-       if (in_changed || out_changed) {
-               PortCountChanged (max (n_outputs(), n_inputs())); /* EMIT SIGNAL */
-               _session.set_dirty ();
-       }
-
-       return 0;
-}
 
-int
-IO::ensure_inputs (ChanCount count, bool clear, bool lockit, void* src)
-{
-       bool changed = false;
-
-       if (count == n_inputs() && !clear) {
-               return 0;
-       }
-
-       if (lockit) {
-               BLOCK_PROCESS_CALLBACK ();
-               Glib::Mutex::Lock im (io_lock);
-               changed = ensure_inputs_locked (count, clear, src);
-       } else {
-               changed = ensure_inputs_locked (count, clear, src);
-       }
-
-       if (changed) {
-               input_changed (ConfigurationChanged, src); /* EMIT SIGNAL */
-               setup_bundle_for_inputs ();
-               _session.set_dirty ();
-       }
-       return 0;
-}
-
-bool
-IO::ensure_outputs_locked (ChanCount count, bool clear, void* src)
-{
-       Port* output_port    = 0;
-       bool  changed        = false;
-       bool  need_pan_reset = false;
-       
-       if (n_outputs() != count) {
-               need_pan_reset = true;
-       }
-       
-       for (DataType::iterator t = DataType::begin(); t != DataType::end(); ++t) {
-
-               const size_t n = count.get(*t);
-
-               /* remove unused ports */
-               for (size_t i = n_outputs().get(*t); i > n; --i) {
-                       output_port = _outputs.port(*t, i-1);
-
-                       assert(output_port);
-                       _outputs.remove(output_port);
-                       _session.engine().unregister_port (*output_port);
-
-                       changed = true;
-               }
-
-               /* create any necessary new ports */
-               while (n_outputs().get(*t) < n) {
-
-                       string portname = build_legal_port_name (*t, false);
-
-                       if ((output_port = _session.engine().register_output_port (*t, portname)) == 0) {
-                               error << string_compose(_("IO: cannot register output port %1"), portname) << endmsg;
-                               return -1;
+                       catch (AudioEngine::PortRegistrationFailure& err) {
+                               /* pass it on */
+                               throw;
                        }
 
-                       _outputs.add (output_port);
+                       _ports.add (port);
                        changed = true;
-                       setup_peak_meters ();
-
-                       if (need_pan_reset) {
-                               reset_panner ();
-                       }
                }
        }
-       
+
        if (changed) {
-               check_bundles_connected_to_outputs ();
-               PortCountChanged (n_outputs()); /* EMIT SIGNAL */
+               check_bundles_connected ();
+               PortCountChanged (n_ports()); /* EMIT SIGNAL */
                _session.set_dirty ();
        }
-       
+
        if (clear) {
                /* disconnect all existing ports so that we get a fresh start */
-               for (PortSet::iterator i = _outputs.begin(); i != _outputs.end(); ++i) {
+               for (PortSet::iterator i = _ports.begin(); i != _ports.end(); ++i) {
                        i->disconnect_all ();
                }
        }
 
-       return changed;
+       return 0;
 }
 
+/** Caller must hold process lock */
 int
-IO::ensure_outputs (ChanCount count, bool clear, bool lockit, void* src)
+IO::ensure_ports (ChanCount count, bool clear, void* src)
 {
-       bool changed = false;
-
-       /* XXX caller should hold io_lock, but generally doesn't */
+#ifndef WIN32
+       assert (!AudioEngine::instance()->process_lock().trylock());
+#endif
 
-       if (lockit) {
-               BLOCK_PROCESS_CALLBACK ();
-               Glib::Mutex::Lock im (io_lock);
-               changed = ensure_outputs_locked (count, clear, src);
-       } else {
-               changed = ensure_outputs_locked (count, clear, src);
-       }
+       bool changed = false;
 
-       if (changed) {
-                output_changed (ConfigurationChanged, src); /* EMIT SIGNAL */
-                setup_bundle_for_outputs ();
+       if (count == n_ports() && !clear) {
+               return 0;
        }
 
-       return 0;
-}
+       IOChange change;
 
-gain_t
-IO::effective_gain () const
-{
-       return _gain_control->get_value();
-}
+       change.before = _ports.count ();
 
-void
-IO::reset_panner ()
-{
-       if (panners_legal) {
-               if (!no_panner_reset) {
-                       _panner->reset (n_outputs().n_audio(), pans_required());
+       {
+               Glib::Threads::Mutex::Lock im (io_lock);
+               if (ensure_ports_locked (count, clear, changed)) {
+                       return -1;
                }
-       } else {
-               panner_legal_c.disconnect ();
-               panner_legal_c = PannersLegal.connect (mem_fun (*this, &IO::panners_became_legal));
        }
-}
 
-int
-IO::panners_became_legal ()
-{
-       _panner->reset (n_outputs().n_audio(), pans_required());
-       _panner->load (); // automation
-       panner_legal_c.disconnect ();
+       if (changed) {
+               change.after = _ports.count ();
+               change.type = IOChange::ConfigurationChanged;
+               this->changed (change, src); /* EMIT SIGNAL */
+               _buffers.attach_buffers (_ports);
+               setup_bundle ();
+               _session.set_dirty ();
+       }
+
        return 0;
 }
 
-void
-IO::defer_pan_reset ()
+/** Caller must hold process lock */
+int
+IO::ensure_io (ChanCount count, bool clear, void* src)
 {
-       no_panner_reset = true;
-}
+#ifndef WIN32
+       assert (!AudioEngine::instance()->process_lock().trylock());
+#endif
 
-void
-IO::allow_pan_reset ()
-{
-       no_panner_reset = false;
-       reset_panner ();
+       return ensure_ports (count, clear, src);
 }
 
-
 XMLNode&
-IO::get_state (void)
+IO::get_state ()
 {
        return state (true);
 }
 
 XMLNode&
-IO::state (bool full_state)
+IO::state (bool /*full_state*/)
 {
        XMLNode* node = new XMLNode (state_node_name);
        char buf[64];
@@ -1123,117 +527,64 @@ IO::state (bool full_state)
        vector<string>::iterator ci;
        int n;
        LocaleGuard lg (X_("POSIX"));
-       Glib::Mutex::Lock lm (io_lock);
+       Glib::Threads::Mutex::Lock lm (io_lock);
 
        node->add_property("name", _name);
        id().print (buf, sizeof (buf));
        node->add_property("id", buf);
+       node->add_property ("direction", enum_2_string (_direction));
+       node->add_property ("default-type", _default_type.to_string());
 
-       for (
-         std::vector<UserBundleInfo>::iterator i = _bundles_connected_to_inputs.begin();
-         i != _bundles_connected_to_inputs.end();
-         ++i
-         )
-       {
-               XMLNode* n = new XMLNode ("InputBundle");
-               n->add_property ("name", i->bundle->name ());
+       for (std::vector<UserBundleInfo*>::iterator i = _bundles_connected.begin(); i != _bundles_connected.end(); ++i) {
+               XMLNode* n = new XMLNode ("Bundle");
+               n->add_property ("name", (*i)->bundle->name ());
                node->add_child_nocopy (*n);
        }
 
-       for (
-         std::vector<UserBundleInfo>::iterator i = _bundles_connected_to_outputs.begin();
-         i != _bundles_connected_to_outputs.end();
-         ++i
-         )
-       {
-               XMLNode* n = new XMLNode ("OutputBundle");
-               n->add_property ("name", i->bundle->name ());
-               node->add_child_nocopy (*n);
-       }
-       
-       str = "";
+       for (PortSet::iterator i = _ports.begin(); i != _ports.end(); ++i) {
 
-       for (PortSet::iterator i = _inputs.begin(); i != _inputs.end(); ++i) {
-                       
                vector<string> connections;
 
+               XMLNode* pnode = new XMLNode (X_("Port"));
+               pnode->add_property (X_("type"), i->type().to_string());
+               pnode->add_property (X_("name"), i->name());
+
                if (i->get_connections (connections)) {
 
-                       str += '{';
-                       
                        for (n = 0, ci = connections.begin(); ci != connections.end(); ++ci, ++n) {
-                               if (n) {
-                                       str += ',';
-                               }
-                               
+
                                /* if its a connection to our own port,
                                   return only the port name, not the
                                   whole thing. this allows connections
                                   to be re-established even when our
                                   client name is different.
                                */
-                               
-                               str += _session.engine().make_port_name_relative (*ci);
-                       }       
-                       
-                       str += '}';
 
-               } else {
-                       str += "{}";
-               }
-       }
-       
-       node->add_property ("inputs", str);
+                               XMLNode* cnode = new XMLNode (X_("Connection"));
 
-       str = "";
-       
-       for (PortSet::iterator i = _outputs.begin(); i != _outputs.end(); ++i) {
-               
-               vector<string> connections;
-
-               if (i->get_connections (connections)) {
-                       
-                       str += '{';
-                       
-                       for (n = 0, ci = connections.begin(); ci != connections.end(); ++ci, ++n) {
-                               if (n) {
-                                       str += ',';
-                               }
-                               
-                               str += _session.engine().make_port_name_relative (*ci);
+                               cnode->add_property (X_("other"), _session.engine().make_port_name_relative (*ci));
+                               pnode->add_child_nocopy (*cnode);
                        }
-                       
-                       str += '}';
-
-               } else {
-                       str += "{}";
                }
-       }
-       
-       node->add_property ("outputs", str);
-
-       node->add_child_nocopy (_panner->state (full_state));
-       node->add_child_nocopy (_gain_control->get_state ());
-
-       snprintf (buf, sizeof(buf), "%2.12f", gain());
-       node->add_property ("gain", buf);
-
-       /* port counts */
 
-       node->add_child_nocopy(*n_inputs().state("Inputs"));
-       node->add_child_nocopy(*n_outputs().state("Outputs"));
+               node->add_child_nocopy (*pnode);
+       }
 
-       /* automation */
+       snprintf (buf, sizeof (buf), "%" PRId64, _user_latency);
+       node->add_property (X_("user-latency"), buf);
        
-       if (full_state)
-               node->add_child_nocopy (get_automation_state());
-
        return *node;
 }
 
 int
-IO::set_state (const XMLNode& node)
+IO::set_state (const XMLNode& node, int version)
 {
+       /* callers for version < 3000 need to call set_state_2X directly, as A3 IOs
+        * are input OR output, not both, so the direction needs to be specified
+        * by the caller.
+        */
+       assert (version >= 3000);
+
        const XMLProperty* prop;
        XMLNodeConstIterator iter;
        LocaleGuard lg (X_("POSIX"));
@@ -1248,162 +599,90 @@ IO::set_state (const XMLNode& node)
        }
 
        if ((prop = node.property ("name")) != 0) {
-               _name = prop->value();
-               /* used to set panner name with this, but no more */
+               set_name (prop->value());
        }
 
-       if ((prop = node.property ("id")) != 0) {
-               _id = prop->value ();
+       if ((prop = node.property (X_("default-type"))) != 0) {
+               _default_type = DataType(prop->value());
+               assert(_default_type != DataType::NIL);
        }
 
-       if ((prop = node.property ("gain")) != 0) {
-               set_gain (atof (prop->value().c_str()), this);
-               _gain = _gain_control->user_float();
-       }
+       set_id (node);
 
-       if ((prop = node.property ("automation-state")) != 0 || (prop = node.property ("automation-style")) != 0) {
-               /* old school automation handling */
+       if ((prop = node.property ("direction")) != 0) {
+               _direction = (Direction) string_2_enum (prop->value(), _direction);
        }
 
-       for (iter = node.children().begin(); iter != node.children().end(); ++iter) {
-
-               // Old school Panner.
-               if ((*iter)->name() == "Panner") {
-                       if (!_panner) {
-                               _panner = boost::shared_ptr<Panner>(new Panner (_name, _session));
-                       }
-                       _panner->set_state (**iter);
-               }
-
-               if ((*iter)->name() == "Processor") {
-                       if ((*iter)->property ("type") && ((*iter)->property ("type")->value() == "panner" ) ) {
-                               if (!_panner) {
-                                       _panner = boost::shared_ptr<Panner>(new Panner (_name, _session));
-                               }
-                               _panner->set_state (**iter);
-                       }
-               }
-
-               if ((*iter)->name() == X_("Automation")) {
-
-                       set_automation_state (*(*iter), Evoral::Parameter(GainAutomation));
-               }
-
-               if ((*iter)->name() == X_("Controllable")) {
-                       if ((prop = (*iter)->property("name")) != 0 && prop->value() == "gaincontrol") {
-                               _gain_control->set_state (**iter);
-                       }
-               }
-       }
-
-       if (ports_legal) {
-
-               if (create_ports (node)) {
-                       return -1;
-               }
-
-       } else {
-
-               port_legal_c = PortsLegal.connect (mem_fun (*this, &IO::ports_became_legal));
-       }
-
-       if (!_panner) {
-               _panner = boost::shared_ptr<Panner>(new Panner (_name, _session));
-       }
-
-       if (panners_legal) {
-               reset_panner ();
-       } else {
-               panner_legal_c = PannersLegal.connect (mem_fun (*this, &IO::panners_became_legal));
+       if (create_ports (node, version)) {
+               return -1;
        }
 
        if (connecting_legal) {
 
-               if (make_connections (node)) {
+               if (make_connections (node, version, false)) {
                        return -1;
                }
 
        } else {
-               
-               connection_legal_c = ConnectingLegal.connect (mem_fun (*this, &IO::connecting_became_legal));
-       }
 
-       if (!ports_legal || !connecting_legal) {
                pending_state_node = new XMLNode (node);
+               pending_state_node_version = version;
+               pending_state_node_in = false;
+               ConnectingLegal.connect_same_thread (connection_legal_c, boost::bind (&IO::connecting_became_legal, this));
+       }
+
+       if ((prop = node.property ("user-latency")) != 0) {
+               _user_latency = atoi (prop->value ());
        }
 
        return 0;
 }
 
 int
-IO::load_automation (string path)
+IO::set_state_2X (const XMLNode& node, int version, bool in)
 {
-       string fullpath;
-       ifstream in;
-       char line[128];
-       uint32_t linecnt = 0;
-       float version;
+       const XMLProperty* prop;
+       XMLNodeConstIterator iter;
        LocaleGuard lg (X_("POSIX"));
 
-       fullpath = Glib::build_filename(_session.automation_dir(), path);
-
-       in.open (fullpath.c_str());
+       /* force use of non-localized representation of decimal point,
+          since we use it a lot in XML files and so forth.
+       */
 
-       if (!in) {
-               fullpath = Glib::build_filename(_session.automation_dir(), _session.snap_name() + '-' + path);
+       if (node.name() != state_node_name) {
+               error << string_compose(_("incorrect XML node \"%1\" passed to IO object"), node.name()) << endmsg;
+               return -1;
+       }
 
-               in.open (fullpath.c_str());
+       if ((prop = node.property ("name")) != 0) {
+               set_name (prop->value());
+       }
 
-               if (!in) {
-                       error << string_compose(_("%1: cannot open automation event file \"%2\""), _name, fullpath) << endmsg;
-                       return -1;
-               }
+       if ((prop = node.property (X_("default-type"))) != 0) {
+               _default_type = DataType(prop->value());
+               assert(_default_type != DataType::NIL);
        }
 
-       clear_automation ();
+       set_id (node);
 
-       while (in.getline (line, sizeof(line), '\n')) {
-               char type;
-               nframes_t when;
-               double value;
+       _direction = in ? Input : Output;
 
-               if (++linecnt == 1) {
-                       if (memcmp (line, "version", 7) == 0) {
-                               if (sscanf (line, "version %f", &version) != 1) {
-                                       error << string_compose(_("badly formed version number in automation event file \"%1\""), path) << endmsg;
-                                       return -1;
-                               }
-                       } else {
-                               error << string_compose(_("no version information in automation event file \"%1\""), path) << endmsg;
-                               return -1;
-                       }
+       if (create_ports (node, version)) {
+               return -1;
+       }
 
-                       continue;
-               }
+       if (connecting_legal) {
 
-               if (sscanf (line, "%c %" PRIu32 " %lf", &type, &when, &value) != 3) {
-                       warning << string_compose(_("badly formatted automation event record at line %1 of %2 (ignored)"), linecnt, path) << endmsg;
-                       continue;
+               if (make_connections_2X (node, version, in)) {
+                       return -1;
                }
 
-               switch (type) {
-               case 'g':
-                       _gain_control->list()->fast_simple_add (when, value);
-                       break;
-
-               case 's':
-                       break;
-
-               case 'm':
-                       break;
-
-               case 'p':
-                       /* older (pre-1.0) versions of ardour used this */
-                       break;
+       } else {
 
-               default:
-                       warning << _("dubious automation event found (and ignored)") << endmsg;
-               }
+               pending_state_node = new XMLNode (node);
+               pending_state_node_version = version;
+               pending_state_node_in = in;
+               ConnectingLegal.connect_same_thread (connection_legal_c, boost::bind (&IO::connecting_became_legal, this));
        }
 
        return 0;
@@ -1414,50 +693,24 @@ IO::connecting_became_legal ()
 {
        int ret;
 
-       if (pending_state_node == 0) {
-               fatal << _("IO::connecting_became_legal() called without a pending state node") << endmsg;
-               /*NOTREACHED*/
-               return -1;
-       }
+       assert (pending_state_node);
 
        connection_legal_c.disconnect ();
 
-       ret = make_connections (*pending_state_node);
-
-       if (ports_legal) {
-               delete pending_state_node;
-               pending_state_node = 0;
-       }
-
-       return ret;
-}
-int
-IO::ports_became_legal ()
-{
-       int ret;
-
-       if (pending_state_node == 0) {
-               fatal << _("IO::ports_became_legal() called without a pending state node") << endmsg;
-               /*NOTREACHED*/
-               return -1;
-       }
-
-       port_legal_c.disconnect ();
-
-       ret = create_ports (*pending_state_node);
+       ret = make_connections (*pending_state_node, pending_state_node_version, pending_state_node_in);
 
-       if (connecting_legal) {
-               delete pending_state_node;
-               pending_state_node = 0;
-       }
+       delete pending_state_node;
+       pending_state_node = 0;
 
        return ret;
 }
 
 boost::shared_ptr<Bundle>
-IO::find_possible_bundle (const string &desired_name, const string &default_name, const string &bundle_type_name) 
+IO::find_possible_bundle (const string &desired_name)
 {
        static const string digits = "0123456789";
+       const string &default_name = (_direction == Input ? _("in") : _("out"));
+       const string &bundle_type_name = (_direction == Input ? _("input") : _("output"));
 
        boost::shared_ptr<Bundle> c = _session.bundle_by_name (desired_name);
 
@@ -1472,7 +725,7 @@ IO::find_possible_bundle (const string &desired_name, const string &default_name
 
                // find numeric suffix of desired name
                bundle_number = 0;
-               
+
                last_non_digit_pos = desired_name.find_last_not_of(digits);
 
                if (last_non_digit_pos != string::npos) {
@@ -1480,16 +733,16 @@ IO::find_possible_bundle (const string &desired_name, const string &default_name
                        s << desired_name.substr(last_non_digit_pos);
                        s >> bundle_number;
                }
-       
+
                // see if it's a stereo connection e.g. "in 3+4"
 
                if (last_non_digit_pos > 1 && desired_name[last_non_digit_pos] == '+') {
-                       int left_bundle_number = 0;
                        string::size_type left_last_non_digit_pos;
 
                        left_last_non_digit_pos = desired_name.find_last_not_of(digits, last_non_digit_pos-1);
 
                        if (left_last_non_digit_pos != string::npos) {
+                               int left_bundle_number = 0;
                                stringstream s;
                                s << desired_name.substr(left_last_non_digit_pos, last_non_digit_pos-1);
                                s >> left_bundle_number;
@@ -1508,22 +761,22 @@ IO::find_possible_bundle (const string &desired_name, const string &default_name
                // find highest set bit
                mask = 1;
                while ((mask <= bundle_number) && (mask <<= 1)) {}
-               
-               // "wrap" bundle number into largest possible power of 2 
+
+               // "wrap" bundle number into largest possible power of 2
                // that works...
 
                while (mask) {
 
                        if (bundle_number & mask) {
                                bundle_number &= ~mask;
-                               
+
                                stringstream s;
                                s << default_name << " " << bundle_number + 1;
 
                                if (stereo) {
                                        s << "+" << bundle_number + 2;
                                }
-                               
+
                                possible_name = s.str();
 
                                if ((c = _session.bundle_by_name (possible_name)) != 0) {
@@ -1547,212 +800,317 @@ IO::find_possible_bundle (const string &desired_name, const string &default_name
 }
 
 int
-IO::get_port_counts (const XMLNode& node, ChanCount& in, ChanCount& out,
-                    boost::shared_ptr<Bundle>& ic, boost::shared_ptr<Bundle>& oc)
+IO::get_port_counts_2X (XMLNode const & node, int /*version*/, ChanCount& n, boost::shared_ptr<Bundle>& /*c*/)
 {
+       XMLProperty const * prop;
+       XMLNodeList children = node.children ();
+
+       uint32_t n_audio = 0;
+
+       for (XMLNodeIterator i = children.begin(); i != children.end(); ++i) {
+
+               if ((prop = node.property ("inputs")) != 0 && _direction == Input) {
+                       n_audio = count (prop->value().begin(), prop->value().end(), '{');
+               } else if ((prop = node.property ("input-connection")) != 0 && _direction == Input) {
+                       n_audio = 1;
+               } else if ((prop = node.property ("outputs")) != 0 && _direction == Output) {
+                       n_audio = count (prop->value().begin(), prop->value().end(), '{');
+               } else if ((prop = node.property ("output-connection")) != 0 && _direction == Output) {
+                       n_audio = 2;
+               }
+       }
+
+       ChanCount cnt;
+       cnt.set_audio (n_audio);
+       n = ChanCount::max (n, cnt);
+
+       return 0;
+}
+
+int
+IO::get_port_counts (const XMLNode& node, int version, ChanCount& n, boost::shared_ptr<Bundle>& c)
+{
+       if (version < 3000) {
+               return get_port_counts_2X (node, version, n, c);
+       }
+
        XMLProperty const * prop;
        XMLNodeConstIterator iter;
+       uint32_t n_audio = 0;
+       uint32_t n_midi = 0;
+       ChanCount cnt;
 
-       in = n_inputs();
-       out = n_outputs();
+       n = n_ports();
 
-       for (iter = node.children().begin(); iter != node.children().end(); ++iter) {
-               if ((*iter)->name() == X_("Inputs")) {
-                       in = ChanCount::max(in, ChanCount(**iter));
-               } else if ((*iter)->name() == X_("Outputs")) {
-                       out = ChanCount::max(out, ChanCount(**iter));
+       if ((prop = node.property ("connection")) != 0) {
+
+               if ((c = find_possible_bundle (prop->value())) != 0) {
+                       n = ChanCount::max (n, c->nchannels());
                }
+               return 0;
        }
 
-       if ((prop = node.property ("input-connection")) != 0) {
+       for (iter = node.children().begin(); iter != node.children().end(); ++iter) {
 
-               ic = find_possible_bundle (prop->value(), _("in"), _("input"));
-               if (ic) {
-                       in = ChanCount::max(in, ChanCount(ic->type(), ic->nchannels()));
+               if ((*iter)->name() == X_("Bundle")) {
+                       if ((c = find_possible_bundle (prop->value())) != 0) {
+                               n = ChanCount::max (n, c->nchannels());
+                               return 0;
+                       } else {
+                               return -1;
+                       }
                }
 
-       } else if ((prop = node.property ("inputs")) != 0) {
+               if ((*iter)->name() == X_("Port")) {
+                       prop = (*iter)->property (X_("type"));
 
-               in = ChanCount::max(in, ChanCount(_default_type,
-                                                 count (prop->value().begin(), prop->value().end(), '{')));
-       }
-       
-       if ((prop = node.property ("output-connection")) != 0) {
-               
-               oc = find_possible_bundle (prop->value(), _("out"), _("output"));
-               if (oc) {
-                       out = ChanCount::max(out, ChanCount(oc->type(), oc->nchannels()));
+                       if (!prop) {
+                               continue;
+                       }
+
+                       if (prop->value() == X_("audio")) {
+                               cnt.set_audio (++n_audio);
+                       } else if (prop->value() == X_("midi")) {
+                               cnt.set_midi (++n_midi);
+                       }
                }
-               
-       } else if ((prop = node.property ("outputs")) != 0) {
-               
-               out = ChanCount::max(out, ChanCount(_default_type,
-                                                   count (prop->value().begin(), prop->value().end(), '{')));
        }
-       
+
+       n = ChanCount::max (n, cnt);
        return 0;
 }
 
 int
-IO::create_ports (const XMLNode& node)
+IO::create_ports (const XMLNode& node, int version)
 {
-       if (pending_state_node) {
+       ChanCount n;
+       boost::shared_ptr<Bundle> c;
 
-               ChanCount in;
-               ChanCount out;
-               boost::shared_ptr<Bundle> ic;
-               boost::shared_ptr<Bundle> oc;
-               
-               no_panner_reset = true;
-               
-               get_port_counts (*pending_state_node, in, out, ic, oc);
-               
-               if (ensure_io (in, out, true, this)) {
+       get_port_counts (node, version, n, c);
+
+       {
+               Glib::Threads::Mutex::Lock lm (AudioEngine::instance()->process_lock ());
+
+               if (ensure_ports (n, true, this)) {
                        error << string_compose(_("%1: cannot create I/O ports"), _name) << endmsg;
                        return -1;
                }
-               
-               /* XXX use ic and oc if relevant */
-               
-               no_panner_reset = false;
        }
 
-       set_deferred_state ();
+       /* XXX use c */
+
        return 0;
 }
 
 int
-IO::make_connections (const XMLNode& node)
+IO::make_connections (const XMLNode& node, int version, bool in)
 {
+       if (version < 3000) {
+               return make_connections_2X (node, version, in);
+       }
+
        const XMLProperty* prop;
 
-       if ((prop = node.property ("input-connection")) != 0) {
-               boost::shared_ptr<Bundle> c = find_possible_bundle (prop->value(), _("in"), _("input"));
-               
-               if (!c) {
-                       return -1;
-               }
+       for (XMLNodeConstIterator i = node.children().begin(); i != node.children().end(); ++i) {
 
-               if (n_inputs().get(c->type()) == c->nchannels() && c->ports_are_outputs()) {
-                       connect_input_ports_to_bundle (c, this);
+               if ((*i)->name() == "Bundle") {
+                       XMLProperty const * prop = (*i)->property ("name");
+                       if (prop) {
+                               boost::shared_ptr<Bundle> b = find_possible_bundle (prop->value());
+                               if (b) {
+                                       connect_ports_to_bundle (b, true, this);
+                               }
+                       }
+
+                       return 0;
                }
 
-       } else if ((prop = node.property ("inputs")) != 0) {
-               if (set_inputs (prop->value())) {
-                       error << string_compose(_("improper input channel list in XML node (%1)"), prop->value()) << endmsg;
-                       return -1;
+               if ((*i)->name() == "Port") {
+
+                       prop = (*i)->property (X_("name"));
+
+                       if (!prop) {
+                               continue;
+                       }
+
+                       boost::shared_ptr<Port> p = port_by_name (prop->value());
+
+                       if (p) {
+                               for (XMLNodeConstIterator c = (*i)->children().begin(); c != (*i)->children().end(); ++c) {
+
+                                       XMLNode* cnode = (*c);
+
+                                       if (cnode->name() != X_("Connection")) {
+                                               continue;
+                                       }
+
+                                       if ((prop = cnode->property (X_("other"))) == 0) {
+                                               continue;
+                                       }
+
+                                       if (prop) {
+                                                connect (p, prop->value(), this);
+                                       }
+                               }
+                       }
                }
        }
 
-       if ((prop = node.property ("output-connection")) != 0) {
-               boost::shared_ptr<Bundle> c = find_possible_bundle (prop->value(), _("out"), _("output"));
-               
-               if (!c) {
-                       return -1;
-               } 
-               
-               if (n_outputs().get(c->type()) == c->nchannels() && c->ports_are_inputs()) {
-                       connect_output_ports_to_bundle (c, this);
-               }
+       return 0;
+}
 
-       } else if ((prop = node.property ("outputs")) != 0) {
-               if (set_outputs (prop->value())) {
-                       error << string_compose(_("improper output channel list in XML node (%1)"), prop->value()) << endmsg;
-                       return -1;
+void
+IO::prepare_for_reset (XMLNode& node, const std::string& name)
+{
+       /* reset name */
+       node.add_property ("name", name);
+
+       /* now find connections and reset the name of the port
+          in one so that when we re-use it it will match
+          the name of the thing we're applying it to.
+       */
+
+       XMLProperty* prop;
+       XMLNodeList children = node.children();
+
+       for (XMLNodeIterator i = children.begin(); i != children.end(); ++i) {
+
+               if ((*i)->name() == "Port") {
+                       
+                       prop = (*i)->property (X_("name"));
+                       
+                       if (prop) {
+                               string new_name;
+                               string old = prop->value();
+                               string::size_type slash = old.find ('/');
+
+                               if (slash != string::npos) {
+                                       /* port name is of form: <IO-name>/<port-name> */
+                                       
+                                       new_name = name;
+                                       new_name += old.substr (old.find ('/'));
+                                       
+                                       prop->set_value (new_name);
+                               }
+                       }
                }
        }
+}
+
+
+int
+IO::make_connections_2X (const XMLNode& node, int /*version*/, bool in)
+{
+       const XMLProperty* prop;
+
+       /* XXX: bundles ("connections" as was) */
+
+       if ((prop = node.property ("inputs")) != 0 && in) {
+
+               string::size_type ostart = 0;
+               string::size_type start = 0;
+               string::size_type end = 0;
+               int i = 0;
+               int n;
+               vector<string> ports;
+
+               string const str = prop->value ();
+
+               while ((start = str.find_first_of ('{', ostart)) != string::npos) {
+                       start += 1;
+
+                       if ((end = str.find_first_of ('}', start)) == string::npos) {
+                               error << string_compose(_("IO: badly formed string in XML node for inputs \"%1\""), str) << endmsg;
+                               return -1;
+                       }
+
+                       if ((n = parse_io_string (str.substr (start, end - start), ports)) < 0) {
+                               error << string_compose(_("bad input string in XML node \"%1\""), str) << endmsg;
+
+                               return -1;
 
-       for (XMLNodeConstIterator i = node.children().begin(); i != node.children().end(); ++i) {
+                       } else if (n > 0) {
 
-               if ((*i)->name() == "InputBundle") {
-                       XMLProperty const * prop = (*i)->property ("name");
-                       if (prop) {
-                               boost::shared_ptr<Bundle> b = find_possible_bundle (prop->value(), _("in"), _("input"));
-                               if (b) {
-                                       connect_input_ports_to_bundle (b, this);
+
+                               for (int x = 0; x < n; ++x) {
+                                       /* XXX: this is a bit of a hack; need to check if it's always valid */
+                                       string::size_type const p = ports[x].find ("/out");
+                                       if (p != string::npos) {
+                                               ports[x].replace (p, 4, "/audio_out");
+                                       }
+                                       nth(i)->connect (ports[x]);
                                }
                        }
-                       
-               } else if ((*i)->name() == "OutputBundle") {
-                       XMLProperty const * prop = (*i)->property ("name");
-                       if (prop) {
-                               boost::shared_ptr<Bundle> b = find_possible_bundle (prop->value(), _("out"), _("output"));
-                               if (b) {
-                                       connect_output_ports_to_bundle (b, this);
-                               } 
-                       }
+
+                       ostart = end+1;
+                       i++;
                }
-       }
-       
-       return 0;
-}
 
-int
-IO::set_inputs (const string& str)
-{
-       vector<string> ports;
-       int i;
-       int n;
-       uint32_t nports;
-       
-       if ((nports = count (str.begin(), str.end(), '{')) == 0) {
-               return 0;
        }
 
-       // FIXME: audio-only
-       if (ensure_inputs (ChanCount(DataType::AUDIO, nports), true, true, this)) {
-               return -1;
-       }
+       if ((prop = node.property ("outputs")) != 0 && !in) {
 
-       string::size_type start, end, ostart;
+               string::size_type ostart = 0;
+               string::size_type start = 0;
+               string::size_type end = 0;
+               int i = 0;
+               int n;
+               vector<string> ports;
 
-       ostart = 0;
-       start = 0;
-       end = 0;
-       i = 0;
+               string const str = prop->value ();
 
-       while ((start = str.find_first_of ('{', ostart)) != string::npos) {
-               start += 1;
+               while ((start = str.find_first_of ('{', ostart)) != string::npos) {
+                       start += 1;
 
-               if ((end = str.find_first_of ('}', start)) == string::npos) {
-                       error << string_compose(_("IO: badly formed string in XML node for inputs \"%1\""), str) << endmsg;
-                       return -1;
-               }
+                       if ((end = str.find_first_of ('}', start)) == string::npos) {
+                               error << string_compose(_("IO: badly formed string in XML node for outputs \"%1\""), str) << endmsg;
+                               return -1;
+                       }
 
-               if ((n = parse_io_string (str.substr (start, end - start), ports)) < 0) {
-                       error << string_compose(_("bad input string in XML node \"%1\""), str) << endmsg;
+                       if ((n = parse_io_string (str.substr (start, end - start), ports)) < 0) {
+                               error << string_compose(_("IO: bad output string in XML node \"%1\""), str) << endmsg;
 
-                       return -1;
-                       
-               } else if (n > 0) {
+                               return -1;
 
-                       for (int x = 0; x < n; ++x) {
-                               connect_input (input (i), ports[x], this);
+                       } else if (n > 0) {
+
+                               for (int x = 0; x < n; ++x) {
+                                       /* XXX: this is a bit of a hack; need to check if it's always valid */
+                                       string::size_type const p = ports[x].find ("/in");
+                                       if (p != string::npos) {
+                                               ports[x].replace (p, 3, "/audio_in");
+                                       }
+                                       nth(i)->connect (ports[x]);
+                               }
                        }
-               }
 
-               ostart = end+1;
-               i++;
+                       ostart = end+1;
+                       i++;
+               }
        }
 
        return 0;
 }
 
 int
-IO::set_outputs (const string& str)
+IO::set_ports (const string& str)
 {
        vector<string> ports;
        int i;
        int n;
        uint32_t nports;
-       
+
        if ((nports = count (str.begin(), str.end(), '{')) == 0) {
                return 0;
        }
 
-       // FIXME: audio-only - need a way to identify port types from XML/string
-       if (ensure_outputs (ChanCount(DataType::AUDIO, nports), true, true, this)) {
-               return -1;
+       {
+               Glib::Threads::Mutex::Lock lm (AudioEngine::instance()->process_lock ());
+
+               // FIXME: audio-only
+               if (ensure_ports (ChanCount(DataType::AUDIO, nports), true, this)) {
+                       return -1;
+               }
        }
 
        string::size_type start, end, ostart;
@@ -1766,19 +1124,19 @@ IO::set_outputs (const string& str)
                start += 1;
 
                if ((end = str.find_first_of ('}', start)) == string::npos) {
-                       error << string_compose(_("IO: badly formed string in XML node for outputs \"%1\""), str) << endmsg;
+                       error << string_compose(_("IO: badly formed string in XML node for inputs \"%1\""), str) << endmsg;
                        return -1;
                }
 
                if ((n = parse_io_string (str.substr (start, end - start), ports)) < 0) {
-                       error << string_compose(_("IO: bad output string in XML node \"%1\""), str) << endmsg;
+                       error << string_compose(_("bad input string in XML node \"%1\""), str) << endmsg;
 
                        return -1;
-                       
+
                } else if (n > 0) {
 
                        for (int x = 0; x < n; ++x) {
-                               connect_output (output (i), ports[x], this);
+                               connect (nth (i), ports[x], this);
                        }
                }
 
@@ -1807,7 +1165,7 @@ IO::parse_io_string (const string& str, vector<string>& ports)
                ports.push_back (str.substr (opos, pos - opos));
                opos = pos + 1;
        }
-       
+
        if (opos < str.length()) {
                ports.push_back (str.substr(opos));
        }
@@ -1828,7 +1186,7 @@ IO::parse_gain_string (const string& str, vector<string>& ports)
                ports.push_back (str.substr (opos, pos - opos));
                opos = pos + 1;
        }
-       
+
        if (opos < str.length()) {
                ports.push_back (str.substr(opos));
        }
@@ -1839,160 +1197,70 @@ IO::parse_gain_string (const string& str, vector<string>& ports)
 bool
 IO::set_name (const string& requested_name)
 {
-       if (requested_name == _name) {
+       string name = requested_name;
+
+       if (_name == name) {
                return true;
        }
-       
-       string name;
-       Route *rt;
-       if ( (rt = dynamic_cast<Route *>(this))) {
-               name = Route::ensure_track_or_route_name(requested_name, _session);
-       } else {
-               name = requested_name;
-       }
-
 
        /* replace all colons in the name. i wish we didn't have to do this */
 
-       if (replace_all (name, ":", "-")) {
-               warning << _("you cannot use colons to name objects with I/O connections") << endmsg;
-       }
-
-       for (PortSet::iterator i = _inputs.begin(); i != _inputs.end(); ++i) {
-               string current_name = i->name();
-               current_name.replace (current_name.find (_name), _name.length(), name);
-               i->set_name (current_name);
-       }
+       replace_all (name, ":", "-");
 
-       for (PortSet::iterator i = _outputs.begin(); i != _outputs.end(); ++i) {
+       for (PortSet::iterator i = _ports.begin(); i != _ports.end(); ++i) {
                string current_name = i->name();
-               current_name.replace (current_name.find (_name), _name.length(), name);
+               current_name.replace (current_name.find (_name), _name.val().length(), name);
                i->set_name (current_name);
        }
 
-       bool const r = SessionObject::set_name(name);
+       bool const r = SessionObject::set_name (name);
 
-       setup_bundles_for_inputs_and_outputs ();
+       setup_bundle ();
 
        return r;
 }
 
-void
-IO::set_port_latency (nframes_t nframes)
-{
-       Glib::Mutex::Lock lm (io_lock);
-
-       for (PortSet::iterator i = _outputs.begin(); i != _outputs.end(); ++i) {
-               i->set_latency (nframes);
-       }
-}
-
-nframes_t
-IO::output_latency () const
+framecnt_t
+IO::latency () const
 {
-       nframes_t max_latency;
-       nframes_t latency;
+       framecnt_t max_latency;
+       framecnt_t latency;
 
        max_latency = 0;
 
        /* io lock not taken - must be protected by other means */
 
-       for (PortSet::const_iterator i = _outputs.begin(); i != _outputs.end(); ++i) {
-               if ((latency = i->total_latency ()) > max_latency) {
+       for (PortSet::const_iterator i = _ports.begin(); i != _ports.end(); ++i) {
+               if ((latency = i->private_latency_range (_direction == Output).max) > max_latency) {
+                        DEBUG_TRACE (DEBUG::Latency, string_compose ("port %1 has %2 latency of %3 - use\n",
+                                                                     name(),
+                                                                     ((_direction == Output) ? "PLAYBACK" : "CAPTURE"),
+                                                                     latency));
                        max_latency = latency;
                }
        }
 
-       return max_latency;
-}
-
-nframes_t
-IO::input_latency () const
-{
-       nframes_t max_latency;
-       nframes_t latency;
-
-       max_latency = 0;
-
-       /* io lock not taken - must be protected by other means */
-
-       for (PortSet::const_iterator i = _inputs.begin(); i != _inputs.end(); ++i) {
-               if ((latency = i->total_latency ()) > max_latency) {
-                       max_latency = latency;
-               } 
-       }
-
+        DEBUG_TRACE (DEBUG::Latency, string_compose ("%1: max %4 latency from %2 ports = %3\n",
+                                                     name(), _ports.num_ports(), max_latency,
+                                                     ((_direction == Output) ? "PLAYBACK" : "CAPTURE")));
        return max_latency;
 }
 
 int
-IO::connect_input_ports_to_bundle (boost::shared_ptr<Bundle> c, void* src)
+IO::connect_ports_to_bundle (boost::shared_ptr<Bundle> c, bool exclusive, void* src)
 {
-       {
-               BLOCK_PROCESS_CALLBACK ();
-               Glib::Mutex::Lock lm2 (io_lock);
-
-               c->connect (_bundle_for_inputs, _session.engine());
-
-               /* If this is a UserBundle, make a note of what we've done */
-
-               boost::shared_ptr<UserBundle> ub = boost::dynamic_pointer_cast<UserBundle> (c);
-               if (ub) {
-
-                       /* See if we already know about this one */
-                       std::vector<UserBundleInfo>::iterator i = _bundles_connected_to_inputs.begin();
-                       while (i != _bundles_connected_to_inputs.end() && i->bundle != ub) {
-                               ++i;
-                       }
-
-                       if (i == _bundles_connected_to_inputs.end()) {
-                               /* We don't, so make a note */
-                               _bundles_connected_to_inputs.push_back (UserBundleInfo (this, ub));
-                       }
-               }
-       }
-
-       input_changed (IOChange (ConfigurationChanged|ConnectionsChanged), src); /* EMIT SIGNAL */
-       return 0;
-}
+       BLOCK_PROCESS_CALLBACK ();
 
-int
-IO::disconnect_input_ports_from_bundle (boost::shared_ptr<Bundle> c, void* src)
-{
        {
-               BLOCK_PROCESS_CALLBACK ();
-               Glib::Mutex::Lock lm2 (io_lock);
-
-               c->disconnect (_bundle_for_inputs, _session.engine());
-                       
-               /* If this is a UserBundle, make a note of what we've done */
-
-               boost::shared_ptr<UserBundle> ub = boost::dynamic_pointer_cast<UserBundle> (c);
-               if (ub) {
+               Glib::Threads::Mutex::Lock lm2 (io_lock);
 
-                       std::vector<UserBundleInfo>::iterator i = _bundles_connected_to_inputs.begin();
-                       while (i != _bundles_connected_to_inputs.end() && i->bundle != ub) {
-                               ++i;
-                       }
-
-                       if (i != _bundles_connected_to_inputs.end()) {
-                               _bundles_connected_to_inputs.erase (i);
+               if (exclusive) {
+                       for (PortSet::iterator i = _ports.begin(); i != _ports.end(); ++i) {
+                               i->disconnect_all ();
                        }
                }
-       }
-
-       input_changed (IOChange (ConfigurationChanged|ConnectionsChanged), src); /* EMIT SIGNAL */
-       return 0;
-}
 
-int
-IO::connect_output_ports_to_bundle (boost::shared_ptr<Bundle> c, void* src)
-{
-       {
-               BLOCK_PROCESS_CALLBACK ();
-               Glib::Mutex::Lock lm2 (io_lock);
-
-               c->connect (_bundle_for_outputs, _session.engine());
+               c->connect (_bundle, _session.engine());
 
                /* If this is a UserBundle, make a note of what we've done */
 
@@ -2000,313 +1268,111 @@ IO::connect_output_ports_to_bundle (boost::shared_ptr<Bundle> c, void* src)
                if (ub) {
 
                        /* See if we already know about this one */
-                       std::vector<UserBundleInfo>::iterator i = _bundles_connected_to_outputs.begin();
-                       while (i != _bundles_connected_to_outputs.end() && i->bundle != ub) {
+                       std::vector<UserBundleInfo*>::iterator i = _bundles_connected.begin();
+                       while (i != _bundles_connected.end() && (*i)->bundle != ub) {
                                ++i;
                        }
 
-                       if (i == _bundles_connected_to_outputs.end()) {
+                       if (i == _bundles_connected.end()) {
                                /* We don't, so make a note */
-                               _bundles_connected_to_outputs.push_back (UserBundleInfo (this, ub));
+                               _bundles_connected.push_back (new UserBundleInfo (this, ub));
                        }
                }
        }
 
-       output_changed (IOChange (ConnectionsChanged|ConfigurationChanged), src); /* EMIT SIGNAL */
-
+       changed (IOChange (IOChange::ConnectionsChanged), src); /* EMIT SIGNAL */
        return 0;
 }
 
 int
-IO::disconnect_output_ports_from_bundle (boost::shared_ptr<Bundle> c, void* src)
+IO::disconnect_ports_from_bundle (boost::shared_ptr<Bundle> c, void* src)
 {
+       BLOCK_PROCESS_CALLBACK ();
+
        {
-               BLOCK_PROCESS_CALLBACK ();
-               Glib::Mutex::Lock lm2 (io_lock);
+               Glib::Threads::Mutex::Lock lm2 (io_lock);
+
+               c->disconnect (_bundle, _session.engine());
 
-               c->disconnect (_bundle_for_outputs, _session.engine());
-                       
                /* If this is a UserBundle, make a note of what we've done */
 
                boost::shared_ptr<UserBundle> ub = boost::dynamic_pointer_cast<UserBundle> (c);
                if (ub) {
 
-                       std::vector<UserBundleInfo>::iterator i = _bundles_connected_to_outputs.begin();
-                       while (i != _bundles_connected_to_outputs.end() && i->bundle != ub) {
+                       std::vector<UserBundleInfo*>::iterator i = _bundles_connected.begin();
+                       while (i != _bundles_connected.end() && (*i)->bundle != ub) {
                                ++i;
                        }
 
-                       if (i != _bundles_connected_to_outputs.end()) {
-                               _bundles_connected_to_outputs.erase (i);
-                       }
-               }
-       }
-
-       output_changed (IOChange (ConfigurationChanged|ConnectionsChanged), src); /* EMIT SIGNAL */
-       return 0;
-}
-
-
-int
-IO::disable_connecting ()
-{
-       connecting_legal = false;
-       return 0;
-}
-
-int
-IO::enable_connecting ()
-{
-       connecting_legal = true;
-       return ConnectingLegal ();
-}
-
-int
-IO::disable_ports ()
-{
-       ports_legal = false;
-       return 0;
-}
-
-int
-IO::enable_ports ()
-{
-       ports_legal = true;
-       return PortsLegal ();
-}
-
-int
-IO::disable_panners (void)
-{
-       panners_legal = false;
-       return 0;
-}
-
-int
-IO::reset_panners ()
-{
-       panners_legal = true;
-       return PannersLegal ();
-}
-
-void
-IO::bundle_changed (Bundle::Change c)
-{
-       //XXX
-//     connect_input_ports_to_bundle (_input_bundle, this);
-}
-
-void
-IO::GainControl::set_value (float val)
-{
-       // max gain at about +6dB (10.0 ^ ( 6 dB * 0.05))
-       if (val > 1.99526231f)
-               val = 1.99526231f;
-
-       _io->set_gain (val, this);
-       
-       AutomationControl::set_value(val);
-}
-
-float
-IO::GainControl::get_value (void) const
-{
-       return AutomationControl::get_value();
-}
-
-void
-IO::setup_peak_meters()
-{
-       ChanCount max_streams = std::max (_inputs.count(), _outputs.count());
-       _meter->configure_io (max_streams, max_streams);
-}
-
-/**
-    Update the peak meters.
-
-    The meter signal lock is taken to prevent modification of the 
-    Meter signal while updating the meters, taking the meter signal
-    lock prior to taking the io_lock ensures that all IO will remain 
-    valid while metering.
-*/   
-void
-IO::update_meters()
-{
-       Glib::Mutex::Lock guard (m_meter_signal_lock);
-       Meter(); /* EMIT SIGNAL */
-}
-
-void
-IO::meter ()
-{
-       // FIXME: Ugly.  Meter should manage the lock, if it's necessary
-       
-       Glib::Mutex::Lock lm (io_lock); // READER: meter thread.
-       _meter->meter();
-}
-
-void
-IO::clear_automation ()
-{
-       data().clear_controls (); // clears gain automation
-       _panner->data().clear_controls ();
-}
-
-void
-IO::set_parameter_automation_state (Evoral::Parameter param, AutoState state)
-{
-       // XXX: would be nice to get rid of this special hack
-
-       if (param.type() == GainAutomation) {
-
-               bool changed = false;
-
-               { 
-                       Glib::Mutex::Lock lm (control_lock());
-
-                       boost::shared_ptr<AutomationList> gain_auto
-                               = boost::dynamic_pointer_cast<AutomationList>(_gain_control->list());
-
-                       if (state != gain_auto->automation_state()) {
-                               changed = true;
-                               _last_automation_snapshot = 0;
-                               gain_auto->set_automation_state (state);
-
-                               if (state != Off) {
-                                       // FIXME: shouldn't this use Curve?
-                                       set_gain (gain_auto->eval (_session.transport_frame()), this);
-                               }
+                       if (i != _bundles_connected.end()) {
+                               delete *i;
+                               _bundles_connected.erase (i);
                        }
                }
-
-               if (changed) {
-                       _session.set_dirty ();
-               }
-
-       } else {
-               AutomatableControls::set_parameter_automation_state(param, state);
-       }
-}
-
-void
-IO::inc_gain (gain_t factor, void *src)
-{
-       float desired_gain = _gain_control->user_float();
-       if (desired_gain == 0.0f) {
-               set_gain (0.000001f + (0.000001f * factor), src);
-       } else {
-               set_gain (desired_gain + (desired_gain * factor), src);
-       }
-}
-
-void
-IO::set_gain (gain_t val, void *src)
-{
-       // max gain at about +6dB (10.0 ^ ( 6 dB * 0.05))
-       if (val > 1.99526231f) {
-               val = 1.99526231f;
-       }
-
-       //cerr << "set desired gain to " << val << " when curgain = " << _gain_control->get_value () << endl;
-
-       if (src != _gain_control.get()) {
-               _gain_control->set_value(val);
-               // bit twisty, this will come back and call us again
-               // (this keeps control in sync with reality)
-               return;
-       }
-
-       {
-               Glib::Mutex::Lock dm (declick_lock);
-               _gain_control->set_float(val, false);
-       }
-
-       if (_session.transport_stopped()) {
-               // _gain = val;
        }
-       
-       /*
-       if (_session.transport_stopped() && src != 0 && src != this && _gain_control->automation_write()) {
-               _gain_control->list()->add (_session.transport_frame(), val);
-               
-       }
-       */
 
-       _session.set_dirty();
+       changed (IOChange (IOChange::ConnectionsChanged), src); /* EMIT SIGNAL */
+       return 0;
 }
 
-void
-IO::start_pan_touch (uint32_t which)
-{
-       if (which < _panner->npanners()) {
-               (*_panner).pan_control(which)->start_touch();
-       }
-}
 
-void
-IO::end_pan_touch (uint32_t which)
+int
+IO::disable_connecting ()
 {
-       if (which < _panner->npanners()) {
-               (*_panner).pan_control(which)->stop_touch();
-       }
-
+       connecting_legal = false;
+       return 0;
 }
 
-void
-IO::automation_snapshot (nframes_t now, bool force)
+int
+IO::enable_connecting ()
 {
-       AutomatableControls::automation_snapshot (now, force);
-       // XXX: This seems to be wrong. 
-       // drobilla: shouldnt automation_snapshot for panner be called
-       //           "automagically" because its an Automatable now ?
-       //
-       //           we could dump this whole method then. <3
-
-       if (_last_automation_snapshot > now || (now - _last_automation_snapshot) > _automation_interval) {
-               _panner->automation_snapshot (now, force);
-       }
-       
-       _panner->automation_snapshot (now, force);
-       _last_automation_snapshot = now;
+       Glib::Threads::Mutex::Lock lm (AudioEngine::instance()->process_lock());
+       connecting_legal = true;
+       boost::optional<int> r = ConnectingLegal ();
+       return r.get_value_or (0);
 }
 
 void
-IO::transport_stopped (nframes_t frame)
+IO::bundle_changed (Bundle::Change /*c*/)
 {
-       _gain_control->list()->reposition_for_rt_add (frame);
-
-       if (_gain_control->automation_state() != Off) {
-               
-               /* the src=0 condition is a special signal to not propagate 
-                  automation gain changes into the mix group when locating.
-               */
-
-               // FIXME: shouldn't this use Curve?
-               set_gain (_gain_control->list()->eval (frame), 0);
-       }
-
-       _panner->transport_stopped (frame);
+       /* XXX */
+//     connect_input_ports_to_bundle (_input_bundle, this);
 }
 
+
 string
-IO::build_legal_port_name (DataType type, bool in)
+IO::build_legal_port_name (DataType type)
 {
        const int name_size = jack_port_name_size();
        int limit;
        string suffix;
 
        if (type == DataType::AUDIO) {
-               suffix = _("audio");
+               suffix = X_("audio");
        } else if (type == DataType::MIDI) {
-               suffix = _("midi");
+               suffix = X_("midi");
        } else {
                throw unknown_type();
        }
-       
-       if (in) {
-               suffix += _("_in");
+
+       /* note that if "in" or "out" are translated it will break a session
+          across locale switches because a port's connection list will
+          show (old) translated names, but the current port name will
+          use the (new) translated name.
+       */
+
+       if (_sendish) {
+               if (_direction == Input) {
+                       suffix += X_("_return");
+               } else {
+                       suffix += X_("_send");
+               }
        } else {
-               suffix += _("_out");
+               if (_direction == Input) {
+                       suffix += X_("_in");
+               } else {
+                       suffix += X_("_out");
+               }
        }
 
        // allow up to 4 digits for the output port number, plus the slash, suffix and extra space
@@ -2315,63 +1381,28 @@ IO::build_legal_port_name (DataType type, bool in)
 
        char buf1[name_size+1];
        char buf2[name_size+1];
-       
-       snprintf (buf1, name_size+1, ("%.*s/%s"), limit, _name.c_str(), suffix.c_str());
-       
-       int port_number;
-       
-       if (in) {
-               port_number = find_input_port_hole (buf1);
-       } else {
-               port_number = find_output_port_hole (buf1);
-       }
-       
-       snprintf (buf2, name_size+1, "%s %d", buf1, port_number);
-
-       return string (buf2);
-}
-
-int32_t
-IO::find_input_port_hole (const char* base)
-{
-       /* CALLER MUST HOLD IO LOCK */
 
-       uint32_t n;
-
-       if (_inputs.empty()) {
-               return 1;
-       }
+       /* colons are illegal in port names, so fix that */
 
-       /* we only allow up to 4 characters for the port number
-        */
-
-       for (n = 1; n < 9999; ++n) {
-               char buf[jack_port_name_size()];
-               PortSet::iterator i = _inputs.begin();
+       string nom = _name.val();
+       replace_all (nom, ":", ";");
 
-               snprintf (buf, jack_port_name_size(), _("%s %u"), base, n);
+       snprintf (buf1, name_size+1, ("%.*s/%s"), limit, nom.c_str(), suffix.c_str());
 
-               for ( ; i != _inputs.end(); ++i) {
-                       if (i->name() == buf) {
-                               break;
-                       }
-               }
+       int port_number = find_port_hole (buf1);
+       snprintf (buf2, name_size+1, "%s %d", buf1, port_number);
 
-               if (i == _inputs.end()) {
-                       break;
-               }
-       }
-       return n;
+       return string (buf2);
 }
 
 int32_t
-IO::find_output_port_hole (const char* base)
+IO::find_port_hole (const char* base)
 {
        /* CALLER MUST HOLD IO LOCK */
 
        uint32_t n;
 
-       if (_outputs.empty()) {
+       if (_ports.empty()) {
                return 1;
        }
 
@@ -2380,253 +1411,145 @@ IO::find_output_port_hole (const char* base)
 
        for (n = 1; n < 9999; ++n) {
                char buf[jack_port_name_size()];
-               PortSet::iterator i = _outputs.begin();
+               PortSet::iterator i = _ports.begin();
 
                snprintf (buf, jack_port_name_size(), _("%s %u"), base, n);
 
-               for ( ; i != _outputs.end(); ++i) {
+               for ( ; i != _ports.end(); ++i) {
                        if (i->name() == buf) {
                                break;
                        }
                }
 
-               if (i == _outputs.end()) {
+               if (i == _ports.end()) {
                        break;
                }
        }
-       
        return n;
 }
 
-void
-IO::set_active (bool yn)
-{
-       _active = yn; 
-        active_changed(); /* EMIT SIGNAL */
-}
-
-AudioPort*
-IO::audio_input(uint32_t n) const
-{
-       return dynamic_cast<AudioPort*>(input(n));
-}
-
-AudioPort*
-IO::audio_output(uint32_t n) const
-{
-       return dynamic_cast<AudioPort*>(output(n));
-}
-
-MidiPort*
-IO::midi_input(uint32_t n) const
-{
-       return dynamic_cast<MidiPort*>(input(n));
-}
-
-MidiPort*
-IO::midi_output(uint32_t n) const
-{
-       return dynamic_cast<MidiPort*>(output(n));
-}
 
-void
-IO::set_phase_invert (bool yn, void *src)
+boost::shared_ptr<AudioPort>
+IO::audio(uint32_t n) const
 {
-       if (_phase_invert != yn) {
-               _phase_invert = yn;
-               //  phase_invert_changed (src); /* EMIT SIGNAL */
-       }
-}
+       return _ports.nth_audio_port (n);
 
-void
-IO::set_denormal_protection (bool yn, void *src)
-{
-       if (_denormal_protection != yn) {
-               _denormal_protection = yn;
-               //  denormal_protection_changed (src); /* EMIT SIGNAL */
-       }
 }
 
-void
-IO::update_port_total_latencies ()
+boost::shared_ptr<MidiPort>
+IO::midi(uint32_t n) const
 {
-       /* io_lock, not taken: function must be called from Session::process() calltree */
-
-       for (PortSet::iterator i = _inputs.begin(); i != _inputs.end(); ++i) {
-               _session.engine().update_total_latency (*i);
-       }
-
-       for (PortSet::iterator i = _outputs.begin(); i != _outputs.end(); ++i) {
-               _session.engine().update_total_latency (*i);
-       }
+       return _ports.nth_midi_port (n);
 }
 
-
 /**
- *  Setup bundles that describe our inputs and outputs. Also creates bundles if necessary.
+ *  Setup a bundle that describe our inputs or outputs. Also creates the bundle if necessary.
  */
 
 void
-IO::setup_bundles_for_inputs_and_outputs ()
-{
-       setup_bundle_for_inputs ();
-       setup_bundle_for_outputs ();
-}
-
-
-void
-IO::setup_bundle_for_inputs ()
+IO::setup_bundle ()
 {
         char buf[32];
 
-       if (!_bundle_for_inputs) {
-               _bundle_for_inputs.reset (new Bundle (true));
-       }
-
-       _bundle_for_inputs->suspend_signals ();
-
-       _bundle_for_inputs->set_type (default_type ());
-
-       _bundle_for_inputs->remove_channels ();
-
-        snprintf(buf, sizeof (buf), _("%s in"), _name.c_str());
-        _bundle_for_inputs->set_name (buf);
-       uint32_t const ni = inputs().num_ports();
-       for (uint32_t i = 0; i < ni; ++i) {
-               _bundle_for_inputs->add_channel (bundle_channel_name (i, ni));
-               _bundle_for_inputs->set_port (i, _session.engine().make_port_name_non_relative (inputs().port(i)->name()));
+       if (!_bundle) {
+               _bundle.reset (new Bundle (_direction == Input));
        }
 
-       _bundle_for_inputs->resume_signals ();
-}
-
+       _bundle->suspend_signals ();
 
-void
-IO::setup_bundle_for_outputs ()
-{
-        char buf[32];
+       _bundle->remove_channels ();
 
-       if (!_bundle_for_outputs) {
-               _bundle_for_outputs.reset (new Bundle (false));
+       if (_direction == Input) {
+               snprintf(buf, sizeof (buf), _("%s in"), _name.val().c_str());
+       } else {
+               snprintf(buf, sizeof (buf), _("%s out"), _name.val().c_str());
        }
+        _bundle->set_name (buf);
 
-       _bundle_for_outputs->suspend_signals ();
-
-       _bundle_for_outputs->set_type (default_type ());
+       int c = 0;
+       for (DataType::iterator i = DataType::begin(); i != DataType::end(); ++i) {
 
-       _bundle_for_outputs->remove_channels ();
+               uint32_t const N = _ports.count().get (*i);
+               for (uint32_t j = 0; j < N; ++j) {
+                       _bundle->add_channel (bundle_channel_name (j, N, *i), *i);
+                       _bundle->set_port (c, _session.engine().make_port_name_non_relative (_ports.port(*i, j)->name()));
+                       ++c;
+               }
 
-        snprintf(buf, sizeof (buf), _("%s out"), _name.c_str());
-        _bundle_for_outputs->set_name (buf);
-       uint32_t const no = outputs().num_ports();
-       for (uint32_t i = 0; i < no; ++i) {
-               _bundle_for_outputs->add_channel (bundle_channel_name (i, no));
-               _bundle_for_outputs->set_port (i, _session.engine().make_port_name_non_relative (outputs().port(i)->name()));
        }
 
-       _bundle_for_outputs->resume_signals ();
+       _bundle->resume_signals ();
 }
 
-
-/** @return Bundles connected to our inputs */
+/** @return Bundles connected to our ports */
 BundleList
-IO::bundles_connected_to_inputs ()
+IO::bundles_connected ()
 {
        BundleList bundles;
-       
+
        /* User bundles */
-       for (std::vector<UserBundleInfo>::iterator i = _bundles_connected_to_inputs.begin(); i != _bundles_connected_to_inputs.end(); ++i) {
-               bundles.push_back (i->bundle);
+       for (std::vector<UserBundleInfo*>::iterator i = _bundles_connected.begin(); i != _bundles_connected.end(); ++i) {
+               bundles.push_back ((*i)->bundle);
        }
 
        /* Session bundles */
        boost::shared_ptr<ARDOUR::BundleList> b = _session.bundles ();
        for (ARDOUR::BundleList::iterator i = b->begin(); i != b->end(); ++i) {
-               if ((*i)->connected_to (_bundle_for_inputs, _session.engine())) {
+               if ((*i)->connected_to (_bundle, _session.engine())) {
                        bundles.push_back (*i);
                }
        }
 
        /* Route bundles */
-       boost::shared_ptr<ARDOUR::RouteList> r = _session.get_routes ();
-       for (ARDOUR::RouteList::iterator i = r->begin(); i != r->end(); ++i) {
-               if ((*i)->bundle_for_outputs()->connected_to (_bundle_for_inputs, _session.engine())) {
-                       bundles.push_back ((*i)->bundle_for_outputs());
-               }
-       }
-         
-       return bundles;
-}
-
-
-/* @return Bundles connected to our outputs */
-BundleList
-IO::bundles_connected_to_outputs ()
-{
-       BundleList bundles;
 
-       /* User bundles */
-       for (std::vector<UserBundleInfo>::iterator i = _bundles_connected_to_outputs.begin(); i != _bundles_connected_to_outputs.end(); ++i) {
-               bundles.push_back (i->bundle);
-       }
+       boost::shared_ptr<ARDOUR::RouteList> r = _session.get_routes ();
 
-       /* Session bundles */
-       boost::shared_ptr<ARDOUR::BundleList> b = _session.bundles ();
-       for (ARDOUR::BundleList::iterator i = b->begin(); i != b->end(); ++i) {
-               if ((*i)->connected_to (_bundle_for_outputs, _session.engine())) {
-                       bundles.push_back (*i);
+       if (_direction == Input) {
+               for (ARDOUR::RouteList::iterator i = r->begin(); i != r->end(); ++i) {
+                       if ((*i)->output()->bundle()->connected_to (_bundle, _session.engine())) {
+                               bundles.push_back ((*i)->output()->bundle());
+                       }
                }
-       }
-
-       /* Route bundles */
-       boost::shared_ptr<ARDOUR::RouteList> r = _session.get_routes ();
-       for (ARDOUR::RouteList::iterator i = r->begin(); i != r->end(); ++i) {
-               if ((*i)->bundle_for_inputs()->connected_to (_bundle_for_outputs, _session.engine())) {
-                       bundles.push_back ((*i)->bundle_for_inputs());
+       } else {
+               for (ARDOUR::RouteList::iterator i = r->begin(); i != r->end(); ++i) {
+                       if ((*i)->input()->bundle()->connected_to (_bundle, _session.engine())) {
+                               bundles.push_back ((*i)->input()->bundle());
+                       }
                }
        }
 
-       return bundles; 
+       return bundles;
 }
 
 
 IO::UserBundleInfo::UserBundleInfo (IO* io, boost::shared_ptr<UserBundle> b)
 {
        bundle = b;
-       changed = b->Changed.connect (
-               sigc::mem_fun (*io, &IO::bundle_changed)
-               );
+       b->Changed.connect_same_thread (changed, boost::bind (&IO::bundle_changed, io, _1));
 }
 
-void
-IO::prepare_inputs (nframes_t nframes)
+std::string
+IO::bundle_channel_name (uint32_t c, uint32_t n, DataType t) const
 {
-       /* io_lock, not taken: function must be called from Session::process() calltree */
-}
+       char buf[32];
 
-void
-IO::flush_outputs (nframes_t nframes)
-{
-       /* io_lock, not taken: function must be called from Session::process() calltree */
+       if (t == DataType::AUDIO) {
 
-       for (PortSet::iterator i = _outputs.begin(); i != _outputs.end(); ++i) {
-               (*i).flush_buffers (nframes, _output_offset);
-       }
-}
+               switch (n) {
+               case 1:
+                       return _("mono");
+               case 2:
+                       return c == 0 ? _("L") : _("R");
+               default:
+                       snprintf (buf, sizeof(buf), _("%d"), (c + 1));
+                       return buf;
+               }
+
+       } else {
 
-std::string
-IO::bundle_channel_name (uint32_t c, uint32_t n) const
-{
-       char buf[32];
-       
-       switch (n) {
-       case 1:
-               return _("mono");
-       case 2:
-               return c == 0 ? _("L") : _("R");
-       default:
                snprintf (buf, sizeof(buf), _("%d"), (c + 1));
                return buf;
+
        }
 
        return "";
@@ -2636,47 +1559,58 @@ string
 IO::name_from_state (const XMLNode& node)
 {
        const XMLProperty* prop;
-       
+
        if ((prop = node.property ("name")) != 0) {
                return prop->value();
-       } 
-       
+       }
+
        return string();
 }
 
 void
 IO::set_name_in_state (XMLNode& node, const string& new_name)
 {
-       const XMLProperty* prop;
-       
-       if ((prop = node.property ("name")) != 0) {
-               node.add_property ("name", new_name);
-       } 
+       node.add_property (X_("name"), new_name);
+       XMLNodeList children = node.children ();
+       for (XMLNodeIterator i = children.begin(); i != children.end(); ++i) {
+               if ((*i)->name() == X_("Port")) {
+                       string const old_name = (*i)->property(X_("name"))->value();
+                       string const old_name_second_part = old_name.substr (old_name.find_first_of ("/") + 1);
+                       (*i)->add_property (X_("name"), string_compose ("%1/%2", new_name, old_name_second_part));
+               }
+       }
 }
 
-void
-IO::cycle_start (nframes_t nframes)
+bool
+IO::connected () const
 {
-       _output_offset = 0;
-}
+        /* do we have any connections at all? */
 
-void
-IO::increment_output_offset (nframes_t n)
-{
-       _output_offset += n;
+        for (PortSet::const_iterator p = _ports.begin(); p != _ports.end(); ++p) {
+                if (p->connected()) {
+                        return true;
+                }
+        }
+
+        return false;
 }
 
 bool
 IO::connected_to (boost::shared_ptr<const IO> other) const
 {
+       if (!other) {
+                return connected ();
+       }
+
+       assert (_direction != other->direction());
+
        uint32_t i, j;
-       
-       uint32_t no = n_outputs().n_total();
-       uint32_t ni = other->n_inputs ().n_total();
-       
+       uint32_t no = n_ports().n_total();
+       uint32_t ni = other->n_ports ().n_total();
+
        for (i = 0; i < no; ++i) {
                for (j = 0; j < ni; ++j) {
-                       if (output(i)->connected_to (other->input(j)->name())) {
+                       if (nth(i)->connected_to (other->nth(j)->name())) {
                                return true;
                        }
                }
@@ -2685,3 +1619,121 @@ IO::connected_to (boost::shared_ptr<const IO> other) const
        return false;
 }
 
+bool
+IO::connected_to (const string& str) const
+{
+       for (PortSet::const_iterator i = _ports.begin(); i != _ports.end(); ++i) {
+               if (i->connected_to (str)) {
+                       return true;
+               }
+       }
+
+       return false;
+}
+
+/** Call a processor's ::run() method, giving it our buffers
+ *  Caller must hold process lock.
+ */
+void
+IO::process_input (boost::shared_ptr<Processor> proc, framepos_t start_frame, framepos_t end_frame, pframes_t nframes)
+{
+       /* don't read the data into new buffers - just use the port buffers directly */
+
+       if (n_ports().n_total() == 0) {
+               /* We have no ports, so nothing to process */
+               return;
+       }
+
+       _buffers.get_jack_port_addresses (_ports, nframes);
+       if (proc) {
+               proc->run (_buffers, start_frame, end_frame, nframes, true);
+       }
+}
+
+void
+IO::collect_input (BufferSet& bufs, pframes_t nframes, ChanCount offset)
+{
+       assert(bufs.available() >= _ports.count());
+
+       if (_ports.count() == ChanCount::ZERO) {
+               return;
+       }
+
+       bufs.set_count (_ports.count());
+
+       for (DataType::iterator t = DataType::begin(); t != DataType::end(); ++t) {
+               PortSet::iterator   i = _ports.begin(*t);
+               BufferSet::iterator b = bufs.begin(*t);
+
+               for (uint32_t off = 0; off < offset.get(*t); ++off, ++b) {
+                       if (b == bufs.end(*t)) {
+                               continue;
+                       }
+               }
+
+               for ( ; i != _ports.end(*t); ++i, ++b) {
+                       Buffer& bb (i->get_buffer (nframes));
+                       b->read_from (bb, nframes);
+               }
+       }
+}
+
+void
+IO::copy_to_outputs (BufferSet& bufs, DataType type, pframes_t nframes, framecnt_t offset)
+{
+       // Copy any buffers 1:1 to outputs
+
+       PortSet::iterator o = _ports.begin(type);
+       BufferSet::iterator i = bufs.begin(type);
+       BufferSet::iterator prev = i;
+
+       while (i != bufs.end(type) && o != _ports.end (type)) {
+               Buffer& port_buffer (o->get_buffer (nframes));
+               port_buffer.read_from (*i, nframes, offset);
+               prev = i;
+               ++i;
+               ++o;
+       }
+
+       // Copy last buffer to any extra outputs
+
+       while (o != _ports.end(type)) {
+               Buffer& port_buffer (o->get_buffer (nframes));
+               port_buffer.read_from (*prev, nframes, offset);
+               ++o;
+       }
+}
+
+boost::shared_ptr<Port>
+IO::port_by_name (const std::string& str) const
+{
+       /* to be called only from ::set_state() - no locking */
+
+       for (PortSet::const_iterator i = _ports.begin(); i != _ports.end(); ++i) {
+
+               if (i->name() == str) {
+                       return boost::const_pointer_cast<Port> (*i);
+               }
+       }
+
+       return boost::shared_ptr<Port> ();
+}
+
+bool
+IO::physically_connected () const
+{
+       for (PortSet::const_iterator i = _ports.begin(); i != _ports.end(); ++i) {
+                if (i->physically_connected()) {
+                        return true;
+                }
+        }
+
+        return false;
+}
+
+bool
+IO::has_port (boost::shared_ptr<Port> p) const
+{
+       Glib::Threads::Mutex::Lock lm (io_lock);
+       return _ports.contains (p);
+}