Replace connection cerr dumping with DEBUG_TRACE.
[ardour.git] / libs / ardour / session.cc
index 5e56b82e689b7dfa8990d2f1871009516421152b..19c7f5638f3bf9d76b139316b653c5611b0cc3dc 100644 (file)
@@ -17,7 +17,6 @@
 
 */
 
-#define __STDC_LIMIT_MACROS
 #include <stdint.h>
 
 #include <algorithm>
@@ -35,6 +34,8 @@
 #include <glibmm/miscutils.h>
 #include <glibmm/fileutils.h>
 
+#include <boost/algorithm/string/erase.hpp>
+
 #include "pbd/error.h"
 #include "pbd/boost_debug.h"
 #include "pbd/pathscanner.h"
@@ -43,6 +44,7 @@
 #include "pbd/stacktrace.h"
 #include "pbd/file_utils.h"
 #include "pbd/convert.h"
+#include "pbd/strsplit.h"
 
 #include "ardour/amp.h"
 #include "ardour/analyser.h"
 #include "ardour/tempo.h"
 #include "ardour/utils.h"
 #include "ardour/graph.h"
+#include "ardour/speakers.h"
+#include "ardour/operations.h"
 
 #include "midi++/port.h"
 #include "midi++/mmc.h"
+#include "midi++/manager.h"
 
 #include "i18n.h"
 
 using namespace std;
 using namespace ARDOUR;
 using namespace PBD;
-using boost::shared_ptr;
-using boost::weak_ptr;
 
 bool Session::_disable_all_loaded_plugins = false;
 
 PBD::Signal1<void,std::string> Session::Dialog;
 PBD::Signal0<int> Session::AskAboutPendingState;
-PBD::Signal2<int,nframes_t,nframes_t> Session::AskAboutSampleRateMismatch;
+PBD::Signal2<int, framecnt_t, framecnt_t> Session::AskAboutSampleRateMismatch;
 PBD::Signal0<void> Session::SendFeedback;
+PBD::Signal3<int,Session*,std::string,DataType> Session::MissingFile;
 
-PBD::Signal0<void> Session::TimecodeOffsetChanged;
-PBD::Signal0<void> Session::StartTimeChanged;
-PBD::Signal0<void> Session::EndTimeChanged;
+PBD::Signal1<void, framepos_t> Session::StartTimeChanged;
+PBD::Signal1<void, framepos_t> Session::EndTimeChanged;
 PBD::Signal0<void> Session::AutoBindingOn;
 PBD::Signal0<void> Session::AutoBindingOff;
 PBD::Signal2<void,std::string, std::string> Session::Exported;
 PBD::Signal1<int,boost::shared_ptr<Playlist> > Session::AskAboutPlaylistDeletion;
+PBD::Signal0<void> Session::Quit;
 
 static void clean_up_session_event (SessionEvent* ev) { delete ev; }
 const SessionEvent::RTeventCallback Session::rt_cleanup (clean_up_session_event);
 
 Session::Session (AudioEngine &eng,
-                 const string& fullpath,
-                 const string& snapshot_name,
+                  const string& fullpath,
+                  const string& snapshot_name,
                   BusProfile* bus_profile,
-                 string mix_template)
-
-       : _engine (eng),
-         _target_transport_speed (0.0),
-         _requested_return_frame (-1),
-         _mmc (0),
-         _mtc_port (default_mtc_port),
-         _midi_port (default_midi_port),
-         _midi_clock_port (default_midi_clock_port),
-         _session_dir (new SessionDirectory(fullpath)),
-         state_tree (0),
-         _butler (new Butler (*this)),
-         _post_transport_work (0),
-         _send_timecode_update (false),
-         route_graph (new Graph(*this)),
-         routes (new RouteList),
-         _total_free_4k_blocks (0),
-         _bundles (new BundleList),
-         _bundle_xml_node (0),
-         _click_io ((IO*) 0),
-         click_data (0),
-         click_emphasis_data (0),
-         main_outs (0),
-         _metadata (new SessionMetadata()),
-         _have_rec_enabled_track (false)
-
-{
+                  string mix_template)
+       : _engine (eng)
+       , _target_transport_speed (0.0)
+       , _requested_return_frame (-1)
+       , _session_dir (new SessionDirectory(fullpath))
+       , state_tree (0)
+       , _state_of_the_state (Clean)
+       , _butler (new Butler (*this))
+       , _post_transport_work (0)
+       , _send_timecode_update (false)
+       , _all_route_group (new RouteGroup (*this, "all"))
+       , route_graph (new Graph(*this))
+       , routes (new RouteList)
+       , _total_free_4k_blocks (0)
+       , _bundles (new BundleList)
+       , _bundle_xml_node (0)
+       , _current_trans (0)
+       , _click_io ((IO*) 0)
+       , click_data (0)
+       , click_emphasis_data (0)
+       , main_outs (0)
+       , _metadata (new SessionMetadata())
+       , _have_rec_enabled_track (false)
+       , _suspend_timecode_transmission (0)
+{
+       _locations = new Locations (*this);
+               
        playlists.reset (new SessionPlaylists);
-       
+
+       _all_route_group->set_active (true, this);
+
        interpolation.add_channel_to (0, 0);
 
        if (!eng.connected()) {
                throw failed_constructor();
        }
 
-       n_physical_outputs = _engine.n_physical_outputs(DataType::AUDIO);
-       n_physical_inputs =  _engine.n_physical_inputs(DataType::AUDIO);
+       n_physical_outputs = _engine.n_physical_outputs ();
+       n_physical_inputs =  _engine.n_physical_inputs ();
 
        first_stage_init (fullpath, snapshot_name);
 
-        _is_new = !Glib::file_test (_path, Glib::FileTest (G_FILE_TEST_EXISTS | G_FILE_TEST_IS_DIR));
+       _is_new = !Glib::file_test (_path, Glib::FileTest (G_FILE_TEST_EXISTS | G_FILE_TEST_IS_DIR));
 
        if (_is_new) {
                if (create (mix_template, bus_profile)) {
                        destroy ();
                        throw failed_constructor ();
                }
-        }
+       }
 
        if (second_stage_init ()) {
                destroy ();
@@ -198,7 +204,10 @@ Session::Session (AudioEngine &eng,
                DirtyChanged (); /* EMIT SIGNAL */
        }
 
-        _is_new = false;
+       StartTimeChanged.connect_same_thread (*this, boost::bind (&Session::start_time_changed, this, _1));
+       EndTimeChanged.connect_same_thread (*this, boost::bind (&Session::end_time_changed, this, _1));
+
+       _is_new = false;
 }
 
 Session::~Session ()
@@ -236,6 +245,7 @@ Session::destroy ()
        _butler->drop_references ();
        delete _butler;
        delete midi_control_ui;
+       delete _all_route_group;
 
        if (click_data != default_click) {
                delete [] click_data;
@@ -266,7 +276,7 @@ Session::destroy ()
        RegionFactory::delete_all_regions ();
 
        DEBUG_TRACE (DEBUG::Destruction, "delete routes\n");
-       
+
        /* reset these three references to special routes before we do the usual route delete thing */
 
        auditioner.reset ();
@@ -287,8 +297,6 @@ Session::destroy ()
        }
        routes.flush ();
 
-       boost::shared_ptr<RouteList> r = routes.reader ();
-
        DEBUG_TRACE (DEBUG::Destruction, "delete sources\n");
        for (SourceMap::iterator i = sources.begin(); i != sources.end(); ++i) {
                DEBUG_TRACE(DEBUG::Destruction, string_compose ("Dropping for source %1 ; pre-ref = %2\n", i->second->path(), i->second.use_count()));
@@ -305,32 +313,16 @@ Session::destroy ()
 
        Crossfade::set_buffer_size (0);
 
-       delete _mmc;
-
        /* not strictly necessary, but doing it here allows the shared_ptr debugging to work */
        playlists.reset ();
 
-       boost_debug_list_ptrs ();
+       delete _locations;
 
        DEBUG_TRACE (DEBUG::Destruction, "Session::destroy() done\n");
-}
-
-void
-Session::set_worst_io_latencies ()
-{
-       _worst_output_latency = 0;
-       _worst_input_latency = 0;
-
-       if (!_engine.connected()) {
-               return;
-       }
-
-       boost::shared_ptr<RouteList> r = routes.reader ();
 
-       for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
-               _worst_output_latency = max (_worst_output_latency, (*i)->output()->latency());
-               _worst_input_latency = max (_worst_input_latency, (*i)->input()->latency());
-       }
+#ifdef BOOST_SP_ENABLE_DEBUG_HOOKS
+       boost_debug_list_ptrs ();
+#endif
 }
 
 void
@@ -396,36 +388,42 @@ Session::when_engine_running ()
 
                        /* default state for Click: dual-mono to first 2 physical outputs */
 
-                       for (int physport = 0; physport < 2; ++physport) {
-                               string physical_output = _engine.get_nth_physical_output (DataType::AUDIO, physport);
-
-                               if (physical_output.length()) {
-                                       if (_click_io->add_port (physical_output, this)) {
-                                               // relax, even though its an error
-                                      }
-                              }
-                      }
+                       vector<string> outs;
+                       _engine.get_physical_outputs (DataType::AUDIO, outs);
 
-                       if (_click_io->n_ports () > ChanCount::ZERO) {
-                               _clicking = Config->get_clicking ();
-                       }
+                       for (uint32_t physport = 0; physport < 2; ++physport) {
+                               if (outs.size() > physport) {
+                                       if (_click_io->add_port (outs[physport], this)) {
+                                               // relax, even though its an error
+                                       }
+                               }
+                       }
+                       
+                       if (_click_io->n_ports () > ChanCount::ZERO) {
+                               _clicking = Config->get_clicking ();
+                       }
                }
        }
-
+       
        catch (failed_constructor& err) {
                error << _("cannot setup Click I/O") << endmsg;
        }
 
        BootMessage (_("Compute I/O Latencies"));
 
-       set_worst_io_latencies ();
-
        if (_clicking) {
                // XXX HOW TO ALERT UI TO THIS ? DO WE NEED TO?
        }
 
        BootMessage (_("Set up standard connections"));
 
+       vector<string> inputs[DataType::num_types];
+       vector<string> outputs[DataType::num_types];
+       for (uint32_t i = 0; i < DataType::num_types; ++i) {
+               _engine.get_physical_inputs (DataType (DataType::Symbol (i)), inputs[i]);
+               _engine.get_physical_outputs (DataType (DataType::Symbol (i)), outputs[i]);
+       }
+
        /* Create a set of Bundle objects that map
           to the physical I/O currently available.  We create both
           mono and stereo bundles, so that the common cases of mono
@@ -436,28 +434,28 @@ Session::when_engine_running ()
 
        /* mono output bundles */
 
-       for (uint32_t np = 0; np < n_physical_outputs; ++np) {
+       for (uint32_t np = 0; np < outputs[DataType::AUDIO].size(); ++np) {
                char buf[32];
                snprintf (buf, sizeof (buf), _("out %" PRIu32), np+1);
 
-               shared_ptr<Bundle> c (new Bundle (buf, true));
+               boost::shared_ptr<Bundle> c (new Bundle (buf, true));
                c->add_channel (_("mono"), DataType::AUDIO);
-               c->set_port (0, _engine.get_nth_physical_output (DataType::AUDIO, np));
+               c->set_port (0, outputs[DataType::AUDIO][np]);
 
                add_bundle (c);
        }
 
        /* stereo output bundles */
 
-       for (uint32_t np = 0; np < n_physical_outputs; np += 2) {
-               if (np + 1 < n_physical_outputs) {
+       for (uint32_t np = 0; np < outputs[DataType::AUDIO].size(); np += 2) {
+               if (np + 1 < outputs[DataType::AUDIO].size()) {
                        char buf[32];
                        snprintf (buf, sizeof(buf), _("out %" PRIu32 "+%" PRIu32), np + 1, np + 2);
-                       shared_ptr<Bundle> c (new Bundle (buf, true));
+                        boost::shared_ptr<Bundle> c (new Bundle (buf, true));
                        c->add_channel (_("L"), DataType::AUDIO);
-                       c->set_port (0, _engine.get_nth_physical_output (DataType::AUDIO, np));
+                       c->set_port (0, outputs[DataType::AUDIO][np]);
                        c->add_channel (_("R"), DataType::AUDIO);
-                       c->set_port (1, _engine.get_nth_physical_output (DataType::AUDIO, np + 1));
+                       c->set_port (1, outputs[DataType::AUDIO][np + 1]);
 
                        add_bundle (c);
                }
@@ -465,41 +463,67 @@ Session::when_engine_running ()
 
        /* mono input bundles */
 
-       for (uint32_t np = 0; np < n_physical_inputs; ++np) {
+       for (uint32_t np = 0; np < inputs[DataType::AUDIO].size(); ++np) {
                char buf[32];
                snprintf (buf, sizeof (buf), _("in %" PRIu32), np+1);
 
-               shared_ptr<Bundle> c (new Bundle (buf, false));
+               boost::shared_ptr<Bundle> c (new Bundle (buf, false));
                c->add_channel (_("mono"), DataType::AUDIO);
-               c->set_port (0, _engine.get_nth_physical_input (DataType::AUDIO, np));
+               c->set_port (0, inputs[DataType::AUDIO][np]);
 
                add_bundle (c);
        }
 
        /* stereo input bundles */
 
-       for (uint32_t np = 0; np < n_physical_inputs; np += 2) {
-               if (np + 1 < n_physical_inputs) {
+       for (uint32_t np = 0; np < inputs[DataType::AUDIO].size(); np += 2) {
+               if (np + 1 < inputs[DataType::AUDIO].size()) {
                        char buf[32];
                        snprintf (buf, sizeof(buf), _("in %" PRIu32 "+%" PRIu32), np + 1, np + 2);
 
-                       shared_ptr<Bundle> c (new Bundle (buf, false));
+                       boost::shared_ptr<Bundle> c (new Bundle (buf, false));
                        c->add_channel (_("L"), DataType::AUDIO);
-                       c->set_port (0, _engine.get_nth_physical_input (DataType::AUDIO, np));
+                       c->set_port (0, inputs[DataType::AUDIO][np]);
                        c->add_channel (_("R"), DataType::AUDIO);
-                       c->set_port (1, _engine.get_nth_physical_input (DataType::AUDIO, np + 1));
+                       c->set_port (1, inputs[DataType::AUDIO][np + 1]);
 
                        add_bundle (c);
                }
        }
 
+       /* MIDI input bundles */
+
+       for (uint32_t np = 0; np < inputs[DataType::MIDI].size(); ++np) {
+               string n = inputs[DataType::MIDI][np];
+               boost::erase_first (n, X_("alsa_pcm:"));
+               
+               boost::shared_ptr<Bundle> c (new Bundle (n, false));
+               c->add_channel ("", DataType::MIDI);
+               c->set_port (0, inputs[DataType::MIDI][np]);
+               add_bundle (c);
+       }
+               
+       /* MIDI output bundles */
+
+       for (uint32_t np = 0; np < outputs[DataType::MIDI].size(); ++np) {
+               string n = outputs[DataType::MIDI][np];
+               boost::erase_first (n, X_("alsa_pcm:"));
+
+               boost::shared_ptr<Bundle> c (new Bundle (n, true));
+               c->add_channel ("", DataType::MIDI);
+               c->set_port (0, outputs[DataType::MIDI][np]);
+               add_bundle (c);
+       }
+
        BootMessage (_("Setup signal flow and plugins"));
 
        hookup_io ();
 
        if (_is_new && !no_auto_connect()) {
 
-                /* don't connect the master bus outputs if there is a monitor bus */
+               Glib::Mutex::Lock lm (AudioEngine::instance()->process_lock());
+                
+               /* don't connect the master bus outputs if there is a monitor bus */
 
                if (_master_out && Config->get_auto_connect_standard_busses() && !_monitor_out) {
 
@@ -510,7 +534,10 @@ Session::when_engine_running ()
 
                        for (uint32_t n = 0; n < limit; ++n) {
                                Port* p = _master_out->output()->nth (n);
-                               string connect_to = _engine.get_nth_physical_output (DataType (p->type()), n);
+                               string connect_to;
+                               if (outputs[p->type()].size() > n) {
+                                       connect_to = outputs[p->type()][n];
+                               }
 
                                if (!connect_to.empty() && p->connected_to (connect_to) == false) {
                                        if (_master_out->output()->connect (p, connect_to, this)) {
@@ -568,15 +595,18 @@ Session::when_engine_running ()
                                        }
 
                                } else {
-                                        
+
                                        for (DataType::iterator t = DataType::begin(); t != DataType::end(); ++t) {
-                                               uint32_t mod = _engine.n_physical_outputs (*t);
+                                               uint32_t mod = n_physical_outputs.get (*t);
                                                uint32_t limit = _monitor_out->n_outputs().get(*t);
 
                                                for (uint32_t n = 0; n < limit; ++n) {
 
                                                        Port* p = _monitor_out->output()->ports().port(*t, n);
-                                                       string connect_to = _engine.get_nth_physical_output (*t, (n % mod));
+                                                       string connect_to;
+                                                       if (outputs[*t].size() > (n % mod)) {
+                                                               connect_to = outputs[*t][n % mod];
+                                                       }
 
                                                        if (!connect_to.empty()) {
                                                                if (_monitor_out->output()->connect (p, connect_to, this)) {
@@ -594,15 +624,14 @@ Session::when_engine_running ()
                }
        }
 
-       /* catch up on send+insert cnts */
-
        _state_of_the_state = StateOfTheState (_state_of_the_state & ~(CannotSave|Dirty));
 
        /* hook us up to the engine */
 
        BootMessage (_("Connect to engine"));
-
        _engine.set_session (this);
+
+       update_latency_compensation (true);
 }
 
 void
@@ -614,7 +643,6 @@ Session::hookup_io ()
 
        _state_of_the_state = StateOfTheState (_state_of_the_state | InitialConnecting);
 
-
        if (!auditioner) {
 
                /* we delay creating the auditioner till now because
@@ -622,13 +650,12 @@ Session::hookup_io ()
                */
 
                try {
-                        Auditioner* a = new Auditioner (*this);
-                        if (a->init()) {
-                                delete a;
-                                throw failed_constructor();
-                        }
-                        a->use_new_diskstream ();
-                       auditioner.reset (a);
+                       boost::shared_ptr<Auditioner> a (new Auditioner (*this));
+                       if (a->init()) {
+                               throw failed_constructor ();
+                       }
+                       a->use_new_diskstream ();
+                       auditioner = a;
                }
 
                catch (failed_constructor& err) {
@@ -651,32 +678,29 @@ Session::hookup_io ()
 
        Delivery::reset_panners ();
 
-       /* Connect tracks to monitor/listen bus if there is one.
-           Note that in an existing session, the internal sends will
-           already exist, but we want the routes to notice that
-           they connect to the control out specifically.
-         */
+       /* Connect tracks to monitor/listen bus if there is one.  Note that in an
+          existing session, the internal sends will already exist, but we want the
+          routes to notice that they connect to the control out specifically.
+       */
 
-        if (_monitor_out) {
+       if (_monitor_out) {
                boost::shared_ptr<RouteList> r = routes.reader ();
-                for (RouteList::iterator x = r->begin(); x != r->end(); ++x) {
+               for (RouteList::iterator x = r->begin(); x != r->end(); ++x) {
                         
-                        if ((*x)->is_monitor()) {
-                                
-                                /* relax */
+                       if ((*x)->is_monitor()) {
                                 
-                        } else if ((*x)->is_master()) {
+                               /* relax */
                                 
-                                /* relax */
+                       } else if ((*x)->is_master()) {
                                 
-                        } else {
+                               /* relax */
                                 
-                                (*x)->listen_via (_monitor_out,
-                                                  (Config->get_listen_position() == AfterFaderListen ? PostFader : PreFader),
-                                                  false, false);
-                        }
-                }
-        }
+                       } else {
+
+                               (*x)->listen_via_monitor ();
+                       }
+               }
+       }
 
        /* Anyone who cares about input state, wake up and do something */
 
@@ -699,12 +723,6 @@ Session::hookup_io ()
        update_route_solo_state ();
 }
 
-void
-Session::playlist_length_changed ()
-{
-       update_session_range_location_marker ();
-}
-
 void
 Session::track_playlist_changed (boost::weak_ptr<Track> wp)
 {
@@ -716,10 +734,10 @@ Session::track_playlist_changed (boost::weak_ptr<Track> wp)
        boost::shared_ptr<Playlist> playlist;
 
        if ((playlist = track->playlist()) != 0) {
-               playlist->LengthChanged.connect_same_thread (*this, boost::bind (&Session::playlist_length_changed, this));
+               playlist->RegionAdded.connect_same_thread (*this, boost::bind (&Session::playlist_region_added, this, _1));
+               playlist->RangesMoved.connect_same_thread (*this, boost::bind (&Session::playlist_ranges_moved, this, _1));
+               playlist->RegionsExtended.connect_same_thread (*this, boost::bind (&Session::playlist_regions_extended, this, _1));
        }
-
-       update_session_range_location_marker ();
 }
 
 bool
@@ -736,30 +754,26 @@ Session::record_enabling_legal () const
        return true;
 }
 
+void
+Session::set_track_monitor_input_status (bool yn)
+{
+       boost::shared_ptr<RouteList> rl = routes.reader ();
+       for (RouteList::iterator i = rl->begin(); i != rl->end(); ++i) {
+               boost::shared_ptr<AudioTrack> tr = boost::dynamic_pointer_cast<AudioTrack> (*i);
+               if (tr && tr->record_enabled ()) {
+                       //cerr << "switching to input = " << !auto_input << __FILE__ << __LINE__ << endl << endl;
+                       tr->monitor_input (yn);
+               }
+       }
+}
+
 void
 Session::reset_input_monitor_state ()
 {
        if (transport_rolling()) {
-
-               boost::shared_ptr<RouteList> rl = routes.reader ();
-               for (RouteList::iterator i = rl->begin(); i != rl->end(); ++i) {
-                       boost::shared_ptr<Track> tr = boost::dynamic_pointer_cast<Track> (*i);
-                       if (tr && tr->record_enabled ()) {
-                               //cerr << "switching to input = " << !auto_input << __FILE__ << __LINE__ << endl << endl;
-                               tr->monitor_input (Config->get_monitoring_model() == HardwareMonitoring && !config.get_auto_input());
-                       }
-               }
-               
+               set_track_monitor_input_status (Config->get_monitoring_model() == HardwareMonitoring && !config.get_auto_input());
        } else {
-               
-               boost::shared_ptr<RouteList> rl = routes.reader ();
-               for (RouteList::iterator i = rl->begin(); i != rl->end(); ++i) {
-                       boost::shared_ptr<Track> tr = boost::dynamic_pointer_cast<Track> (*i);
-                       if (tr && tr->record_enabled ()) {
-                               //cerr << "switching to input = " << !Config->get_auto_input() << __FILE__ << __LINE__ << endl << endl;
-                               tr->monitor_input (Config->get_monitoring_model() == HardwareMonitoring);
-                       }
-               }
+               set_track_monitor_input_status (Config->get_monitoring_model() == HardwareMonitoring);
        }
 }
 
@@ -777,7 +791,7 @@ Session::auto_punch_start_changed (Location* location)
 void
 Session::auto_punch_end_changed (Location* location)
 {
-       nframes_t when_to_stop = location->end();
+       framepos_t when_to_stop = location->end();
        // when_to_stop += _worst_output_latency + _worst_input_latency;
        replace_event (SessionEvent::PunchOut, when_to_stop);
 }
@@ -785,7 +799,7 @@ Session::auto_punch_end_changed (Location* location)
 void
 Session::auto_punch_changed (Location* location)
 {
-       nframes_t when_to_stop = location->end();
+       framepos_t when_to_stop = location->end();
 
        replace_event (SessionEvent::PunchIn, location->start());
        //when_to_stop += _worst_output_latency + _worst_input_latency;
@@ -832,7 +846,7 @@ Session::set_auto_punch_location (Location* location)
 {
        Location* existing;
 
-       if ((existing = _locations.auto_punch_location()) != 0 && existing != location) {
+       if ((existing = _locations->auto_punch_location()) != 0 && existing != location) {
                punch_connections.drop_connections();
                existing->set_auto_punch (false, this);
                remove_event (existing->start(), SessionEvent::PunchIn);
@@ -869,7 +883,7 @@ Session::set_auto_loop_location (Location* location)
 {
        Location* existing;
 
-       if ((existing = _locations.auto_loop_location()) != 0 && existing != location) {
+       if ((existing = _locations->auto_loop_location()) != 0 && existing != location) {
                loop_connections.drop_connections ();
                existing->set_auto_loop (false, this);
                remove_event (existing->end(), SessionEvent::AutoLoop);
@@ -915,7 +929,7 @@ Session::locations_added (Location *)
 void
 Session::locations_changed ()
 {
-       _locations.apply (*this, &Session::handle_locations_changed);
+       _locations->apply (*this, &Session::handle_locations_changed);
 }
 
 void
@@ -957,33 +971,26 @@ Session::handle_locations_changed (Locations::LocationList& locations)
 void
 Session::enable_record ()
 {
-        while (1) {
-                RecordState rs = (RecordState) g_atomic_int_get (&_record_status);
+       while (1) {
+               RecordState rs = (RecordState) g_atomic_int_get (&_record_status);
                 
-                if (rs == Recording) {
-                        break;
-                }
+               if (rs == Recording) {
+                       break;
+               }
 
-                if (g_atomic_int_compare_and_exchange (&_record_status, rs, Recording)) {
+               if (g_atomic_int_compare_and_exchange (&_record_status, rs, Recording)) {
                         
-                        _last_record_location = _transport_frame;
-                        _mmc->send (MIDI::MachineControlCommand (MIDI::MachineControl::cmdRecordStrobe));
+                       _last_record_location = _transport_frame;
+                       MIDI::Manager::instance()->mmc()->send (MIDI::MachineControlCommand (MIDI::MachineControl::cmdRecordStrobe));
                         
-                        if (Config->get_monitoring_model() == HardwareMonitoring && config.get_auto_input()) {
-                                
-                                boost::shared_ptr<RouteList> rl = routes.reader ();
-                                for (RouteList::iterator i = rl->begin(); i != rl->end(); ++i) {
-                                        boost::shared_ptr<Track> tr = boost::dynamic_pointer_cast<Track> (*i);
-                                        if (tr && tr->record_enabled ()) {
-                                                tr->monitor_input (true);
-                                        }
-                                }
-                        }
+                       if (Config->get_monitoring_model() == HardwareMonitoring && config.get_auto_input()) {
+                               set_track_monitor_input_status (true);
+                       }
                         
-                        RecordStateChanged ();
-                        break;
-                }
-        }
+                       RecordStateChanged ();
+                       break;
+               }
+       }
 }
 
 void
@@ -995,7 +1002,7 @@ Session::disable_record (bool rt_context, bool force)
 
                if ((!Config->get_latched_record_enable () && !play_loop) || force) {
                        g_atomic_int_set (&_record_status, Disabled);
-                       _mmc->send (MIDI::MachineControlCommand (MIDI::MachineControl::cmdRecordExit));
+                       MIDI::Manager::instance()->mmc()->send (MIDI::MachineControlCommand (MIDI::MachineControl::cmdRecordExit));
                } else {
                        if (rs == Recording) {
                                g_atomic_int_set (&_record_status, Enabled);
@@ -1003,14 +1010,7 @@ Session::disable_record (bool rt_context, bool force)
                }
 
                if (Config->get_monitoring_model() == HardwareMonitoring && config.get_auto_input()) {
-
-                       boost::shared_ptr<RouteList> rl = routes.reader ();
-                       for (RouteList::iterator i = rl->begin(); i != rl->end(); ++i) {
-                               boost::shared_ptr<Track> tr = boost::dynamic_pointer_cast<Track> (*i);
-                               if (tr && tr->record_enabled ()) {
-                                       tr->monitor_input (false);
-                               }
-                       }
+                       set_track_monitor_input_status (false);
                }
 
                RecordStateChanged (); /* emit signal */
@@ -1027,14 +1027,7 @@ Session::step_back_from_record ()
        if (g_atomic_int_compare_and_exchange (&_record_status, Recording, Enabled)) {
 
                if (Config->get_monitoring_model() == HardwareMonitoring && config.get_auto_input()) {
-                       boost::shared_ptr<RouteList> rl = routes.reader ();
-                       for (RouteList::iterator i = rl->begin(); i != rl->end(); ++i) {
-                               boost::shared_ptr<Track> tr = boost::dynamic_pointer_cast<Track> (*i);
-                               if (tr && tr->record_enabled ()) {
-                                       //cerr << "switching from input" << __FILE__ << __LINE__ << endl << endl;
-                                       tr->monitor_input (false);
-                               }
-                       }
+                       set_track_monitor_input_status (false);
                }
        }
 }
@@ -1042,32 +1035,38 @@ Session::step_back_from_record ()
 void
 Session::maybe_enable_record ()
 {
+       if (_step_editors > 0) {
+               return;
+       }
+
        g_atomic_int_set (&_record_status, Enabled);
 
-       /* this function is currently called from somewhere other than an RT thread.
-          this save_state() call therefore doesn't impact anything.
+       /* This function is currently called from somewhere other than an RT thread.
+          This save_state() call therefore doesn't impact anything.  Doing it here
+          means that we save pending state of which sources the next record will use,
+          which gives us some chance of recovering from a crash during the record.
        */
-
+       
        save_state ("", true);
-
+       
        if (_transport_speed) {
                if (!config.get_punch_in()) {
                        enable_record ();
                }
        } else {
-               _mmc->send (MIDI::MachineControlCommand (MIDI::MachineControl::cmdRecordPause));
+               MIDI::Manager::instance()->mmc()->send (MIDI::MachineControlCommand (MIDI::MachineControl::cmdRecordPause));
                RecordStateChanged (); /* EMIT SIGNAL */
        }
 
        set_dirty();
 }
 
-nframes64_t
+framepos_t
 Session::audible_frame () const
 {
-       nframes64_t ret;
-       nframes64_t tf;
-       nframes_t offset;
+       framepos_t ret;
+       framepos_t tf;
+       framecnt_t offset;
 
        /* the first of these two possible settings for "offset"
           mean that the audible frame is stationary until
@@ -1079,7 +1078,7 @@ Session::audible_frame () const
           in the absence of any plugin latency compensation
        */
 
-       offset = _worst_output_latency;
+       offset = worst_playback_latency ();
 
        if (offset > current_block_size) {
                offset -= current_block_size;
@@ -1142,9 +1141,9 @@ Session::audible_frame () const
 }
 
 void
-Session::set_frame_rate (nframes_t frames_per_second)
+Session::set_frame_rate (framecnt_t frames_per_second)
 {
-       /** \fn void Session::set_frame_size(nframes_t)
+       /** \fn void Session::set_frame_size(framecnt_t)
                the AudioEngine object that calls this guarantees
                that it will not be called while we are also in
                ::process(). Its fine to do things that block
@@ -1155,7 +1154,7 @@ Session::set_frame_rate (nframes_t frames_per_second)
 
        sync_time_vars();
 
-       Automatable::set_automation_interval ((jack_nframes_t) ceil ((double) frames_per_second * (0.001 * Config->get_automation_interval())));
+       Automatable::set_automation_interval (ceil ((double) frames_per_second * (0.001 * Config->get_automation_interval())));
 
        clear_clicks ();
 
@@ -1168,7 +1167,7 @@ Session::set_frame_rate (nframes_t frames_per_second)
 }
 
 void
-Session::set_block_size (nframes_t nframes)
+Session::set_block_size (pframes_t nframes)
 {
        /* the AudioEngine guarantees
           that it will not be called while we are also in
@@ -1199,48 +1198,14 @@ Session::set_block_size (nframes_t nframes)
        }
 }
 
-void
-Session::set_default_fade (float /*steepness*/, float /*fade_msecs*/)
-{
-#if 0
-       nframes_t fade_frames;
-
-       /* Don't allow fade of less 1 frame */
-
-       if (fade_msecs < (1000.0 * (1.0/_current_frame_rate))) {
-
-               fade_msecs = 0;
-               fade_frames = 0;
-
-       } else {
-
-               fade_frames = (nframes_t) floor (fade_msecs * _current_frame_rate * 0.001);
-
-       }
-
-       default_fade_msecs = fade_msecs;
-       default_fade_steepness = steepness;
-
-       {
-               // jlc, WTF is this!
-               Glib::RWLock::ReaderLock lm (route_lock);
-               AudioRegion::set_default_fade (steepness, fade_frames);
-       }
-
-       set_dirty();
-
-       /* XXX have to do this at some point */
-       /* foreach region using default fade, reset, then
-          refill_all_diskstream_buffers ();
-       */
-#endif
-}
-
 struct RouteSorter {
+    /** @return true to run r1 before r2, otherwise false */
     bool operator() (boost::shared_ptr<Route> r1, boost::shared_ptr<Route> r2) {
            if (r2->feeds (r1)) {
+                   /* r1 fed by r2; run r2 early */
                    return false;
            } else if (r1->feeds (r2)) {
+                   /* r2 fed by r1; run r1 early */
                    return true;
            } else {
                    if (r1->not_fed ()) {
@@ -1252,16 +1217,22 @@ struct RouteSorter {
                                    return true;
                            }
                    } else {
-                           return r1->order_key(N_("signal")) < r2->order_key(N_("signal"));
+                           if (r2->not_fed()) {
+                                   /* r1 has connections, r2 does not; run r2 early */
+                                   return false;
+                           } else {
+                                   /* both r1 and r2 have connections, but not to each other. just use signal order */
+                                   return r1->order_key(N_("signal")) < r2->order_key(N_("signal"));
+                           }
                    }
            }
     }
 };
 
 static void
-trace_terminal (shared_ptr<Route> r1, shared_ptr<Route> rbase)
+trace_terminal (boost::shared_ptr<Route> r1, boost::shared_ptr<Route> rbase)
 {
-       shared_ptr<Route> r2;
+       boost::shared_ptr<Route> r2;
 
        if (r1->feeds (rbase) && rbase->feeds (r1)) {
                info << string_compose(_("feedback loop setup between %1 and %2"), r1->name(), rbase->name()) << endmsg;
@@ -1270,7 +1241,7 @@ trace_terminal (shared_ptr<Route> r1, shared_ptr<Route> rbase)
 
        /* make a copy of the existing list of routes that feed r1 */
 
-        Route::FedBy existing (r1->fed_by());
+       Route::FedBy existing (r1->fed_by());
                         
        /* for each route that feeds r1, recurse, marking it as feeding
           rbase as well.
@@ -1321,7 +1292,7 @@ Session::resort_routes ()
 
        {
                RCUWriter<RouteList> writer (routes);
-               shared_ptr<RouteList> r = writer.get_copy ();
+               boost::shared_ptr<RouteList> r = writer.get_copy ();
                resort_routes_using (r);
                /* writer goes out of scope and forces update */
        }
@@ -1329,24 +1300,24 @@ Session::resort_routes ()
        //route_graph->dump(1);
 
 #ifndef NDEBUG
-        boost::shared_ptr<RouteList> rl = routes.reader ();
-        for (RouteList::iterator i = rl->begin(); i != rl->end(); ++i) {
-                DEBUG_TRACE (DEBUG::Graph, string_compose ("%1 fed by ...\n", (*i)->name()));
+       boost::shared_ptr<RouteList> rl = routes.reader ();
+       for (RouteList::iterator i = rl->begin(); i != rl->end(); ++i) {
+               DEBUG_TRACE (DEBUG::Graph, string_compose ("%1 fed by ...\n", (*i)->name()));
                 
-                const Route::FedBy& fb ((*i)->fed_by());
-
-                for (Route::FedBy::const_iterator f = fb.begin(); f != fb.end(); ++f) {
-                        boost::shared_ptr<Route> sf = f->r.lock();
-                        if (sf) {
-                                DEBUG_TRACE (DEBUG::Graph, string_compose ("\t%1 (sends only ? %2)\n", sf->name(), f->sends_only));
-                        }
-                }
-        }
+               const Route::FedBy& fb ((*i)->fed_by());
+
+               for (Route::FedBy::const_iterator f = fb.begin(); f != fb.end(); ++f) {
+                       boost::shared_ptr<Route> sf = f->r.lock();
+                       if (sf) {
+                               DEBUG_TRACE (DEBUG::Graph, string_compose ("\t%1 (sends only ? %2)\n", sf->name(), f->sends_only));
+                       }
+               }
+       }
 #endif
 
 }
 void
-Session::resort_routes_using (shared_ptr<RouteList> r)
+Session::resort_routes_using (boost::shared_ptr<RouteList> r)
 {
        RouteList::iterator i, j;
 
@@ -1366,7 +1337,7 @@ Session::resort_routes_using (shared_ptr<RouteList> r)
                                continue;
                        }
 
-                        bool via_sends_only;
+                       bool via_sends_only;
 
                        if ((*j)->direct_feeds (*i, &via_sends_only)) {
                                (*i)->add_fed_by (*j, via_sends_only);
@@ -1384,29 +1355,38 @@ Session::resort_routes_using (shared_ptr<RouteList> r)
        route_graph->rechain (r);
 
 #ifndef NDEBUG
-        DEBUG_TRACE (DEBUG::Graph, "Routes resorted, order follows:\n");
+       DEBUG_TRACE (DEBUG::Graph, "Routes resorted, order follows:\n");
        for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
                DEBUG_TRACE (DEBUG::Graph, string_compose ("\t%1 signal order %2\n", 
-                                                           (*i)->name(), (*i)->order_key ("signal")));
+                                                          (*i)->name(), (*i)->order_key ("signal")));
        }
 #endif
 
 }
 
-/** Find the route name starting with \a base with the lowest \a id.
+/** Find a route name starting with \a base, maybe followed by the
+ *  lowest \a id.  \a id will always be added if \a definitely_add_number
+ *  is true on entry; otherwise it will only be added if required
+ *  to make the name unique.
  *
- * Names are constructed like e.g. "Audio 3" for base="Audio" and id=3.
- * The available route name with the lowest ID will be used, and \a id
- * will be set to the ID.
+ *  Names are constructed like e.g. "Audio 3" for base="Audio" and id=3.
+ *  The available route name with the lowest ID will be used, and \a id
+ *  will be set to the ID.
  *
- * \return false if a route name could not be found, and \a track_name
- * and \a id do not reflect a free route name.
+ *  \return false if a route name could not be found, and \a track_name
+ *  and \a id do not reflect a free route name.
  */
 bool
-Session::find_route_name (const char* base, uint32_t& id, char* name, size_t name_len)
+Session::find_route_name (string const & base, uint32_t& id, char* name, size_t name_len, bool definitely_add_number)
 {
+       if (!definitely_add_number && route_by_name (base) == 0) {
+               /* juse use the base */
+               snprintf (name, name_len, "%s", base.c_str());
+               return true;
+       }
+               
        do {
-               snprintf (name, name_len, "%s %" PRIu32, base, id);
+               snprintf (name, name_len, "%s %" PRIu32, base.c_str(), id);
 
                if (route_by_name (name) == 0) {
                        return true;
@@ -1419,69 +1399,74 @@ Session::find_route_name (const char* base, uint32_t& id, char* name, size_t nam
        return false;
 }
 
+/** Count the total ins and outs of all non-hidden tracks in the session and return them in in and out */
 void
-Session::count_existing_route_channels (ChanCount& in, ChanCount& out)
+Session::count_existing_track_channels (ChanCount& in, ChanCount& out)
 {
        in  = ChanCount::ZERO;
        out = ChanCount::ZERO;
-       shared_ptr<RouteList> r = routes.reader ();
+
+       boost::shared_ptr<RouteList> r = routes.reader ();
+
        for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
-               if (!(*i)->is_hidden()) {
-                       in += (*i)->n_inputs();
-                       out     += (*i)->n_outputs();
+                boost::shared_ptr<Track> tr = boost::dynamic_pointer_cast<Track> (*i);
+               if (tr && !tr->is_hidden()) {
+                        cerr << "Using track i/o counts for " << tr->name() << endl;
+                       in  += tr->n_inputs();
+                       out += tr->n_outputs();
                }
        }
 }
 
+/** Caller must not hold process lock
+ *  @param name_template string to use for the start of the name, or "" to use "Midi".
+ */
 list<boost::shared_ptr<MidiTrack> >
-Session::new_midi_track (TrackMode mode, RouteGroup* route_group, uint32_t how_many)
+Session::new_midi_track (TrackMode mode, RouteGroup* route_group, uint32_t how_many, string name_template)
 {
        char track_name[32];
        uint32_t track_id = 0;
-       ChanCount existing_inputs;
-       ChanCount existing_outputs;
        string port;
        RouteList new_routes;
        list<boost::shared_ptr<MidiTrack> > ret;
        uint32_t control_id;
 
-       count_existing_route_channels (existing_inputs, existing_outputs);
-
        control_id = ntracks() + nbusses();
 
+       bool const use_number = (how_many != 1);
+       
        while (how_many) {
-               if (!find_route_name ("Midi", ++track_id, track_name, sizeof(track_name))) {
+               if (!find_route_name (name_template.empty() ? _("Midi") : name_template, ++track_id, track_name, sizeof(track_name), use_number)) {
                        error << "cannot find name for new midi track" << endmsg;
                        goto failed;
                }
 
-               shared_ptr<MidiTrack> track;
+               boost::shared_ptr<MidiTrack> track;
                 
                try {
-                       MidiTrack* mt = new MidiTrack (*this, track_name, Route::Flag (0), mode);
-
-                        if (mt->init ()) {
-                                delete mt;
-                                goto failed;
-                        }
-
-                        mt->use_new_diskstream();
+                       track.reset (new MidiTrack (*this, track_name, Route::Flag (0), mode));
 
-                       boost_debug_shared_ptr_mark_interesting (mt, "Track");
-                       track = boost::shared_ptr<MidiTrack>(mt);
-
-                       if (track->input()->ensure_io (ChanCount(DataType::MIDI, 1), false, this)) {
-                               error << "cannot configure 1 in/1 out configuration for new midi track" << endmsg;
+                       if (track->init ()) {
                                goto failed;
                        }
 
+                       track->use_new_diskstream();
 
-                       if (track->output()->ensure_io (ChanCount(DataType::MIDI, 1), false, this)) {
-                               error << "cannot configure 1 in/1 out configuration for new midi track" << endmsg;
-                               goto failed;
-                       }
+#ifdef BOOST_SP_ENABLE_DEBUG_HOOKS
+                       boost_debug_shared_ptr_mark_interesting (track.get(), "Track");
+#endif
+                       {
+                               Glib::Mutex::Lock lm (AudioEngine::instance()->process_lock ());
+                               if (track->input()->ensure_io (ChanCount(DataType::MIDI, 1), false, this)) {
+                                       error << "cannot configure 1 in/1 out configuration for new midi track" << endmsg;
+                                       goto failed;
+                               }
 
-                       auto_connect_route (track, existing_inputs, existing_outputs);
+                               if (track->output()->ensure_io (ChanCount(DataType::MIDI, 1), false, this)) {
+                                       error << "cannot configure 1 in/1 out configuration for new midi track" << endmsg;
+                                       goto failed;
+                               }
+                       }
 
                        track->non_realtime_input_change();
 
@@ -1512,17 +1497,32 @@ Session::new_midi_track (TrackMode mode, RouteGroup* route_group, uint32_t how_m
 
   failed:
        if (!new_routes.empty()) {
-               add_routes (new_routes, false);
+               add_routes (new_routes, true, false);
                save_state (_current_snapshot_name);
        }
 
        return ret;
 }
 
+/** @param connect_inputs true to connect inputs as well as outputs, false to connect just outputs.
+ *  @param input_start Where to start from when auto-connecting inputs; e.g. if this is 0, auto-connect starting from input 0.
+ *  @param output_start As \a input_start, but for outputs.
+ */
 void
-Session::auto_connect_route (boost::shared_ptr<Route> route,
-               ChanCount& existing_inputs, ChanCount& existing_outputs)
+Session::auto_connect_route (Route* route, ChanCount& existing_inputs, ChanCount& existing_outputs, 
+                             bool with_lock, bool connect_inputs, ChanCount input_start, ChanCount output_start)
 {
+       if (!IO::connecting_legal) {
+                cerr << "Auto-connect ignored because connecting it not legal\n";
+               return;
+       }
+
+       Glib::Mutex::Lock lm (AudioEngine::instance()->process_lock (), Glib::NOT_LOCK);
+
+       if (with_lock) {
+               lm.acquire ();
+       }
+
        /* If both inputs and outputs are auto-connected to physical ports,
           use the max of input and output offsets to ensure auto-connected
           port numbers always match up (e.g. the first audio input and the
@@ -1530,13 +1530,19 @@ Session::auto_connect_route (boost::shared_ptr<Route> route,
           port number).  Otherwise just use the lowest input or output
           offset possible.
        */
+
+       DEBUG_TRACE (DEBUG::Graph,
+                    string_compose("Auto-connect: existing in = %1 out = %2\n",
+                                   existing_inputs, existing_outputs));
+
        const bool in_out_physical =
-                  (Config->get_input_auto_connect() & AutoConnectPhysical)
-               && (Config->get_output_auto_connect() & AutoConnectPhysical);
+               (Config->get_input_auto_connect() & AutoConnectPhysical)
+               && (Config->get_output_auto_connect() & AutoConnectPhysical)
+               && connect_inputs;
 
        const ChanCount in_offset = in_out_physical
                ? ChanCount::max(existing_inputs, existing_outputs)
-               : existing_inputs;
+                : existing_inputs;
 
        const ChanCount out_offset = in_out_physical
                ? ChanCount::max(existing_inputs, existing_outputs)
@@ -1549,17 +1555,30 @@ Session::auto_connect_route (boost::shared_ptr<Route> route,
                _engine.get_physical_outputs (*t, physoutputs);
                _engine.get_physical_inputs (*t, physinputs);
 
-               if (!physinputs.empty()) {
+               if (!physinputs.empty() && connect_inputs) {
                        uint32_t nphysical_in = physinputs.size();
-                       for (uint32_t i = 0; i < route->n_inputs().get(*t) && i < nphysical_in; ++i) {
+
+                       DEBUG_TRACE (DEBUG::Graph,
+                                    string_compose("There are %1 physical inputs of type %2\n",
+                                                   nphysical_in, *t));
+
+                       for (uint32_t i = input_start.get(*t); i < route->n_inputs().get(*t) && i < nphysical_in; ++i) {
                                string port;
 
                                if (Config->get_input_auto_connect() & AutoConnectPhysical) {
+                                       DEBUG_TRACE (DEBUG::Graph,
+                                                    string_compose("Get index %1 + %2 % %3 = %4\n",
+                                                                   in_offset.get(*t), i, nphysical_in,
+                                                                   (in_offset.get(*t) + i) % nphysical_in));
                                        port = physinputs[(in_offset.get(*t) + i) % nphysical_in];
                                }
 
+                               DEBUG_TRACE (DEBUG::Graph,
+                                            string_compose("Connect route %1 IN to %2\n",
+                                                           route->name(), port));
+
                                if (!port.empty() && route->input()->connect (
-                                               route->input()->ports().port(*t, i), port, this)) {
+                                           route->input()->ports().port(*t, i), port, this)) {
                                        break;
                                }
                        }
@@ -1567,7 +1586,7 @@ Session::auto_connect_route (boost::shared_ptr<Route> route,
 
                if (!physoutputs.empty()) {
                        uint32_t nphysical_out = physoutputs.size();
-                       for (uint32_t i = 0; i < route->n_outputs().get(*t); ++i) {
+                       for (uint32_t i = output_start.get(*t); i < route->n_outputs().get(*t); ++i) {
                                string port;
 
                                if (Config->get_output_auto_connect() & AutoConnectPhysical) {
@@ -1579,6 +1598,10 @@ Session::auto_connect_route (boost::shared_ptr<Route> route,
                                        }
                                }
 
+                               DEBUG_TRACE (DEBUG::Graph,
+                                            string_compose("Connect route %1 OUT to %2\n",
+                                                           route->name(), port));
+
                                if (!port.empty() && route->output()->connect (
                                                route->output()->ports().port(*t, i), port, this)) {
                                        break;
@@ -1586,65 +1609,66 @@ Session::auto_connect_route (boost::shared_ptr<Route> route,
                        }
                }
        }
-
-       existing_inputs += route->n_inputs();
-       existing_outputs += route->n_outputs();
 }
 
+/** Caller must not hold process lock
+ *  @param name_template string to use for the start of the name, or "" to use "Audio".
+ */
 list< boost::shared_ptr<AudioTrack> >
-Session::new_audio_track (int input_channels, int output_channels, TrackMode mode, RouteGroup* route_group, uint32_t how_many)
+Session::new_audio_track (
+       int input_channels, int output_channels, TrackMode mode, RouteGroup* route_group, uint32_t how_many, string name_template
+       )
 {
        char track_name[32];
        uint32_t track_id = 0;
-       ChanCount existing_inputs;
-       ChanCount existing_outputs;
        string port;
        RouteList new_routes;
        list<boost::shared_ptr<AudioTrack> > ret;
        uint32_t control_id;
 
-       count_existing_route_channels (existing_inputs, existing_outputs);
-
        control_id = ntracks() + nbusses() + 1;
 
+       bool const use_number = (how_many != 1);
+       
        while (how_many) {
-               if (!find_route_name ("Audio", ++track_id, track_name, sizeof(track_name))) {
+               if (!find_route_name (name_template.empty() ? _("Audio") : name_template, ++track_id, track_name, sizeof(track_name), use_number)) {
                        error << "cannot find name for new audio track" << endmsg;
                        goto failed;
                }
 
-               shared_ptr<AudioTrack> track;
-
+               boost::shared_ptr<AudioTrack> track;
+                
                try {
-                       AudioTrack* at = new AudioTrack (*this, track_name, Route::Flag (0), mode);
-
-                        if (at->init ()) {
-                                delete at;
-                                goto failed;
-                        }
+                       track.reset (new AudioTrack (*this, track_name, Route::Flag (0), mode));
 
-                        at->use_new_diskstream();
-
-                       boost_debug_shared_ptr_mark_interesting (at, "Track");
-                       track = boost::shared_ptr<AudioTrack>(at);
-
-                       if (track->input()->ensure_io (ChanCount(DataType::AUDIO, input_channels), false, this)) {
-                               error << string_compose (
-                                                       _("cannot configure %1 in/%2 out configuration for new audio track"),
-                                                        input_channels, output_channels)
-                                     << endmsg;
+                       if (track->init ()) {
                                goto failed;
                        }
 
-                       if (track->output()->ensure_io (ChanCount(DataType::AUDIO, output_channels), false, this)) {
-                               error << string_compose (
-                                                       _("cannot configure %1 in/%2 out configuration for new audio track"),
-                                                        input_channels, output_channels)
-                                     << endmsg;
-                               goto failed;
-                       }
+                       track->use_new_diskstream();
 
-                       auto_connect_route (track, existing_inputs, existing_outputs);
+#ifdef BOOST_SP_ENABLE_DEBUG_HOOKS
+                       boost_debug_shared_ptr_mark_interesting (track.get(), "Track");
+#endif
+                       {
+                               Glib::Mutex::Lock lm (AudioEngine::instance()->process_lock ());
+
+                               if (track->input()->ensure_io (ChanCount(DataType::AUDIO, input_channels), false, this)) {
+                                       error << string_compose (
+                                               _("cannot configure %1 in/%2 out configuration for new audio track"),
+                                               input_channels, output_channels)
+                                             << endmsg;
+                                       goto failed;
+                               }
+                               
+                               if (track->output()->ensure_io (ChanCount(DataType::AUDIO, output_channels), false, this)) {
+                                       error << string_compose (
+                                               _("cannot configure %1 in/%2 out configuration for new audio track"),
+                                               input_channels, output_channels)
+                                             << endmsg;
+                                       goto failed;
+                               }
+                       }
 
                        if (route_group) {
                                route_group->add (track);
@@ -1676,7 +1700,7 @@ Session::new_audio_track (int input_channels, int output_channels, TrackMode mod
 
   failed:
        if (!new_routes.empty()) {
-               add_routes (new_routes, true);
+               add_routes (new_routes, true, true);
        }
 
        return ret;
@@ -1688,15 +1712,15 @@ Session::set_remote_control_ids ()
        RemoteModel m = Config->get_remote_model();
        bool emit_signal = false;
 
-       shared_ptr<RouteList> r = routes.reader ();
+       boost::shared_ptr<RouteList> r = routes.reader ();
 
        for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
                if (MixerOrdered == m) {
-                       long order = (*i)->order_key(N_("signal"));
+                       int32_t order = (*i)->order_key(N_("signal"));
                        (*i)->set_remote_control_id (order+1, false);
                        emit_signal = true;
                } else if (EditorOrdered == m) {
-                       long order = (*i)->order_key(N_("editor"));
+                       int32_t order = (*i)->order_key(N_("editor"));
                        (*i)->set_remote_control_id (order+1, false);
                        emit_signal = true;
                } else if (UserOrdered == m) {
@@ -1709,65 +1733,63 @@ Session::set_remote_control_ids ()
        }
 }
 
-
+/** Caller must not hold process lock.
+ *  @param name_template string to use for the start of the name, or "" to use "Bus".
+ */
 RouteList
-Session::new_audio_route (bool aux, int input_channels, int output_channels, RouteGroup* route_group, uint32_t how_many)
+Session::new_audio_route (int input_channels, int output_channels, RouteGroup* route_group, uint32_t how_many, string name_template)
 {
        char bus_name[32];
        uint32_t bus_id = 0;
-       ChanCount existing_inputs;
-       ChanCount existing_outputs;
        string port;
        RouteList ret;
        uint32_t control_id;
 
-       count_existing_route_channels (existing_inputs, existing_outputs);
-
        control_id = ntracks() + nbusses() + 1;
 
+       bool const use_number = (how_many != 1);
        while (how_many) {
-               if (!find_route_name ("Bus", ++bus_id, bus_name, sizeof(bus_name))) {
+               if (!find_route_name (name_template.empty () ? _("Bus") : name_template, ++bus_id, bus_name, sizeof(bus_name), use_number)) {
                        error << "cannot find name for new audio bus" << endmsg;
                        goto failure;
                }
 
                try {
-                       Route* rt = new Route (*this, bus_name, Route::Flag(0), DataType::AUDIO);
-
-                        if (rt->init ()) {
-                                delete rt;
-                                goto failure;
-                        }
-
-                       boost_debug_shared_ptr_mark_interesting (rt, "Route");
-                       shared_ptr<Route> bus (rt);
+                       boost::shared_ptr<Route> bus (new Route (*this, bus_name, Route::Flag(0), DataType::AUDIO));
 
-                       if (bus->input()->ensure_io (ChanCount(DataType::AUDIO, input_channels), false, this)) {
-                               error << string_compose (_("cannot configure %1 in/%2 out configuration for new audio track"),
-                                                        input_channels, output_channels)
-                                     << endmsg;
+                       if (bus->init ()) {
                                goto failure;
                        }
 
+#ifdef BOOST_SP_ENABLE_DEBUG_HOOKS
+                       boost_debug_shared_ptr_mark_interesting (bus.get(), "Route");
+#endif
+                       {
+                               Glib::Mutex::Lock lm (AudioEngine::instance()->process_lock ());
 
-                       if (bus->output()->ensure_io (ChanCount(DataType::AUDIO, output_channels), false, this)) {
-                               error << string_compose (_("cannot configure %1 in/%2 out configuration for new audio track"),
-                                                        input_channels, output_channels)
-                                     << endmsg;
-                               goto failure;
+                               if (bus->input()->ensure_io (ChanCount(DataType::AUDIO, input_channels), false, this)) {
+                                       error << string_compose (_("cannot configure %1 in/%2 out configuration for new audio track"),
+                                                                input_channels, output_channels)
+                                             << endmsg;
+                                       goto failure;
+                               }
+                               
+                               
+                               if (bus->output()->ensure_io (ChanCount(DataType::AUDIO, output_channels), false, this)) {
+                                       error << string_compose (_("cannot configure %1 in/%2 out configuration for new audio track"),
+                                                                input_channels, output_channels)
+                                             << endmsg;
+                                       goto failure;
+                               }
                        }
 
-                       auto_connect_route (bus, existing_inputs, existing_outputs);
-
                        if (route_group) {
                                route_group->add (bus);
                        }
                        bus->set_remote_control_id (control_id);
                        ++control_id;
 
-                       if (aux) {
-                               bus->add_internal_return ();
-                       }
+                       bus->add_internal_return ();
 
                        ret.push_back (bus);
                }
@@ -1789,7 +1811,7 @@ Session::new_audio_route (bool aux, int input_channels, int output_channels, Rou
 
   failure:
        if (!ret.empty()) {
-               add_routes (ret, true);
+               add_routes (ret, true, true);
        }
 
        return ret;
@@ -1820,7 +1842,7 @@ Session::new_route_from_template (uint32_t how_many, const std::string& template
                std::string node_name = IO::name_from_state (*node_copy.children().front());
 
                /* generate a new name by adding a number to the end of the template name */
-               if (!find_route_name (node_name.c_str(), ++number, name, sizeof(name))) {
+               if (!find_route_name (node_name.c_str(), ++number, name, sizeof(name), true)) {
                        fatal << _("Session: UINT_MAX routes? impossible!") << endmsg;
                        /*NOTREACHED*/
                }
@@ -1836,7 +1858,7 @@ Session::new_route_from_template (uint32_t how_many, const std::string& template
                Track::zero_diskstream_id_in_xml (node_copy);
 
                try {
-                       shared_ptr<Route> route (XMLRouteFactory (node_copy, 3000));
+                       boost::shared_ptr<Route> route (XMLRouteFactory (node_copy, 3000));
 
                        if (route == 0) {
                                error << _("Session: cannot create track/bus from template description") << endmsg;
@@ -1848,8 +1870,14 @@ Session::new_route_from_template (uint32_t how_many, const std::string& template
                                   picks up the configuration of the route. During session
                                   loading this normally happens in a different way.
                                */
-                               route->input()->changed (IOChange (ConfigurationChanged|ConnectionsChanged), this);
-                               route->output()->changed (IOChange (ConfigurationChanged|ConnectionsChanged), this);
+                               
+                               Glib::Mutex::Lock lm (AudioEngine::instance()->process_lock ());
+                               
+                               IOChange change (IOChange::Type (IOChange::ConfigurationChanged | IOChange::ConnectionsChanged));
+                               change.after = route->input()->n_ports();
+                               route->input()->changed (change, this);
+                               change.after = route->output()->n_ports();
+                               route->output()->changed (change, this);
                        }
 
                        route->set_remote_control_id (control_id);
@@ -1873,18 +1901,23 @@ Session::new_route_from_template (uint32_t how_many, const std::string& template
 
   out:
        if (!ret.empty()) {
-               add_routes (ret, true);
+               add_routes (ret, true, true);
        }
 
        return ret;
 }
 
 void
-Session::add_routes (RouteList& new_routes, bool save)
+Session::add_routes (RouteList& new_routes, bool auto_connect, bool save)
 {
+        ChanCount existing_inputs;
+        ChanCount existing_outputs;
+        
+        count_existing_track_channels (existing_inputs, existing_outputs);
+
        {
                RCUWriter<RouteList> writer (routes);
-               shared_ptr<RouteList> r = writer.get_copy ();
+               boost::shared_ptr<RouteList> r = writer.get_copy ();
                r->insert (r->end(), new_routes.begin(), new_routes.end());
 
 
@@ -1910,6 +1943,7 @@ Session::add_routes (RouteList& new_routes, bool save)
                r->mute_changed.connect_same_thread (*this, boost::bind (&Session::route_mute_changed, this, _1));
                r->output()->changed.connect_same_thread (*this, boost::bind (&Session::set_worst_io_latencies_x, this, _1, _2));
                r->processors_changed.connect_same_thread (*this, boost::bind (&Session::route_processors_changed, this, _1));
+               r->order_key_changed.connect_same_thread (*this, boost::bind (&Session::route_order_key_changed, this));
 
                if (r->is_master()) {
                        _master_out = r;
@@ -1924,6 +1958,16 @@ Session::add_routes (RouteList& new_routes, bool save)
                        tr->PlaylistChanged.connect_same_thread (*this, boost::bind (&Session::track_playlist_changed, this, boost::weak_ptr<Track> (tr)));
                        track_playlist_changed (boost::weak_ptr<Track> (tr));
                        tr->RecordEnableChanged.connect_same_thread (*this, boost::bind (&Session::update_have_rec_enabled_track, this));
+
+                       boost::shared_ptr<MidiTrack> mt = boost::dynamic_pointer_cast<MidiTrack> (tr);
+                       if (mt) {
+                               mt->StepEditStatusChange.connect_same_thread (*this, boost::bind (&Session::step_edit_status_change, this, _1));
+                       }
+               }
+        
+               if (auto_connect) {
+
+                       auto_connect_route (r, existing_inputs, existing_outputs, true);
                }
        }
 
@@ -1931,14 +1975,12 @@ Session::add_routes (RouteList& new_routes, bool save)
 
                for (RouteList::iterator x = new_routes.begin(); x != new_routes.end(); ++x) {
                        if ((*x)->is_monitor()) {
-                                /* relax */
-                        } else if ((*x)->is_master()) {
-                                /* relax */
+                               /* relax */
+                       } else if ((*x)->is_master()) {
+                               /* relax */
                        } else {
-                                (*x)->listen_via (_monitor_out,
-                                                  (Config->get_listen_position() == AfterFaderListen ? PostFader : PreFader),
-                                                  false, false);
-                        }
+                               (*x)->listen_via_monitor ();
+                       }
                }
 
                resort_routes ();
@@ -1960,13 +2002,9 @@ Session::globally_set_send_gains_to_zero (boost::shared_ptr<Route> dest)
        boost::shared_ptr<RouteList> r = routes.reader ();
        boost::shared_ptr<Send> s;
 
-       /* only tracks */
-
        for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
-               if (boost::dynamic_pointer_cast<Track>(*i)) {
-                       if ((s = (*i)->internal_send_for (dest)) != 0) {
-                               s->amp()->gain_control()->set_value (0.0);
-                       }
+               if ((s = (*i)->internal_send_for (dest)) != 0) {
+                       s->amp()->gain_control()->set_value (0.0);
                }
        }
 }
@@ -1977,13 +2015,9 @@ Session::globally_set_send_gains_to_unity (boost::shared_ptr<Route> dest)
        boost::shared_ptr<RouteList> r = routes.reader ();
        boost::shared_ptr<Send> s;
 
-       /* only tracks */
-
        for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
-               if (boost::dynamic_pointer_cast<Track>(*i)) {
-                       if ((s = (*i)->internal_send_for (dest)) != 0) {
-                               s->amp()->gain_control()->set_value (1.0);
-                       }
+               if ((s = (*i)->internal_send_for (dest)) != 0) {
+                       s->amp()->gain_control()->set_value (1.0);
                }
        }
 }
@@ -1994,27 +2028,22 @@ Session::globally_set_send_gains_from_track(boost::shared_ptr<Route> dest)
        boost::shared_ptr<RouteList> r = routes.reader ();
        boost::shared_ptr<Send> s;
 
-       /* only tracks */
-
        for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
-               if (boost::dynamic_pointer_cast<Track>(*i)) {
-                       if ((s = (*i)->internal_send_for (dest)) != 0) {
-                               s->amp()->gain_control()->set_value ((*i)->gain_control()->get_value());
-                       }
+               if ((s = (*i)->internal_send_for (dest)) != 0) {
+                       s->amp()->gain_control()->set_value ((*i)->gain_control()->get_value());
                }
        }
 }
 
+/** @param include_buses true to add sends to buses and tracks, false for just tracks */
 void
-Session::globally_add_internal_sends (boost::shared_ptr<Route> dest, Placement p)
+Session::globally_add_internal_sends (boost::shared_ptr<Route> dest, Placement p, bool include_buses)
 {
        boost::shared_ptr<RouteList> r = routes.reader ();
        boost::shared_ptr<RouteList> t (new RouteList);
 
-       /* only send tracks */
-
        for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
-               if (boost::dynamic_pointer_cast<Track>(*i)) {
+               if (include_buses || boost::dynamic_pointer_cast<Track>(*i)) {
                        t->push_back (*i);
                }
        }
@@ -2039,22 +2068,24 @@ Session::add_internal_sends (boost::shared_ptr<Route> dest, Placement p, boost::
                        continue;
                }
 
-               (*i)->listen_via (dest, p, true, true);
+               (*i)->listen_via (dest, p);
        }
 
        graph_reordered ();
 }
 
 void
-Session::remove_route (shared_ptr<Route> route)
+Session::remove_route (boost::shared_ptr<Route> route)
 {
-        if (((route == _master_out) || (route == _monitor_out)) && !Config->get_allow_special_bus_removal()) {
-                return;
-        }
+       if (((route == _master_out) || (route == _monitor_out)) && !Config->get_allow_special_bus_removal()) {
+               return;
+       }
+
+       route->set_solo (false, this);
 
        {
                RCUWriter<RouteList> writer (routes);
-               shared_ptr<RouteList> rs = writer.get_copy ();
+               boost::shared_ptr<RouteList> rs = writer.get_copy ();
 
                rs->remove (route);
 
@@ -2064,7 +2095,7 @@ Session::remove_route (shared_ptr<Route> route)
                */
 
                if (route == _master_out) {
-                       _master_out = shared_ptr<Route> ();
+                       _master_out = boost::shared_ptr<Route> ();
                }
 
                if (route == _monitor_out) {
@@ -2081,8 +2112,7 @@ Session::remove_route (shared_ptr<Route> route)
                /* writer goes out of scope, forces route list update */
        }
 
-        update_route_solo_state ();
-       update_session_range_location_marker ();
+       update_route_solo_state ();
 
        // We need to disconnect the route's inputs and outputs
 
@@ -2101,13 +2131,22 @@ Session::remove_route (shared_ptr<Route> route)
                }
        }       
 
-       update_latency_compensation (false, false);
+       boost::shared_ptr<MidiTrack> mt = boost::dynamic_pointer_cast<MidiTrack> (route);
+       if (mt && mt->step_editing()) {
+               if (_step_editors > 0) {
+                       _step_editors--;
+               }
+       }
+
+       update_latency_compensation ();
        set_dirty();
 
-        /* flush references out of the graph
-         */
+       /* Re-sort routes to remove the graph's current references to the one that is
+        * going away, then flush old references out of the graph.
+        */
 
-        route_graph->clear_other_chain ();
+       resort_routes ();
+       route_graph->clear_other_chain ();
 
        /* get rid of it from the dead wood collection in the route list manager */
 
@@ -2145,18 +2184,18 @@ Session::route_listen_changed (void* /*src*/, boost::weak_ptr<Route> wpr)
                return;
        }
 
-       if (route->listening()) {
+       if (route->listening_via_monitor ()) {
 
-                if (Config->get_exclusive_solo()) {
-                        /* new listen: disable all other listen */
-                        shared_ptr<RouteList> r = routes.reader ();
-                        for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
-                                if ((*i) == route || (*i)->solo_isolated() || (*i)->is_master() || (*i)->is_monitor() || (*i)->is_hidden()) {
-                                        continue;
-                                
-                                (*i)->set_listen (false, this);
-                        }
-                }
+               if (Config->get_exclusive_solo()) {
+                       /* new listen: disable all other listen */
+                       boost::shared_ptr<RouteList> r = routes.reader ();
+                       for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
+                               if ((*i) == route || (*i)->solo_isolated() || (*i)->is_master() || (*i)->is_monitor() || (*i)->is_hidden()) {
+                                       continue;
+                               } 
+                               (*i)->set_listen (false, this);
+                       }
+               }
 
                _listen_cnt++;
 
@@ -2164,6 +2203,8 @@ Session::route_listen_changed (void* /*src*/, boost::weak_ptr<Route> wpr)
 
                _listen_cnt--;
        }
+
+       update_route_solo_state ();
 }
 void
 Session::route_solo_isolated_changed (void* /*src*/, boost::weak_ptr<Route> wpr)
@@ -2176,32 +2217,32 @@ Session::route_solo_isolated_changed (void* /*src*/, boost::weak_ptr<Route> wpr)
                return;
        }
         
-        bool send_changed = false;
-
-        if (route->solo_isolated()) {
-                if (_solo_isolated_cnt == 0) {
-                        send_changed = true;
-                }
-                _solo_isolated_cnt++;
-        } else if (_solo_isolated_cnt > 0) {
-                _solo_isolated_cnt--;
-                if (_solo_isolated_cnt == 0) {
-                        send_changed = true;
-                }
-        }
+       bool send_changed = false;
 
-        if (send_changed) {
-                IsolatedChanged (); /* EMIT SIGNAL */
-        }
+       if (route->solo_isolated()) {
+               if (_solo_isolated_cnt == 0) {
+                       send_changed = true;
+               }
+               _solo_isolated_cnt++;
+       } else if (_solo_isolated_cnt > 0) {
+               _solo_isolated_cnt--;
+               if (_solo_isolated_cnt == 0) {
+                       send_changed = true;
+               }
+       }
+
+       if (send_changed) {
+               IsolatedChanged (); /* EMIT SIGNAL */
+       }
 }
             
 void
 Session::route_solo_changed (bool self_solo_change, void* /*src*/, boost::weak_ptr<Route> wpr)
 {
-        if (!self_solo_change) {
-                // session doesn't care about changes to soloed-by-others
-                return;
-        }
+       if (!self_solo_change) {
+               // session doesn't care about changes to soloed-by-others
+               return;
+       }
 
        if (solo_update_disabled) {
                // We know already
@@ -2216,7 +2257,7 @@ Session::route_solo_changed (bool self_solo_change, void* /*src*/, boost::weak_p
                return;
        }
         
-       shared_ptr<RouteList> r = routes.reader ();
+       boost::shared_ptr<RouteList> r = routes.reader ();
        int32_t delta;
 
        if (route->self_soloed()) {
@@ -2225,59 +2266,59 @@ Session::route_solo_changed (bool self_solo_change, void* /*src*/, boost::weak_p
                delta = -1;
        }
  
-        if (delta == 1 && Config->get_exclusive_solo()) {
-                /* new solo: disable all other solos */
-                for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
-                        if ((*i) == route || (*i)->solo_isolated() || (*i)->is_master() || (*i)->is_monitor() || (*i)->is_hidden()) {
-                                continue;
-                        
-                        (*i)->set_solo (false, this);
-                }
-        }
+       if (delta == 1 && Config->get_exclusive_solo()) {
+               /* new solo: disable all other solos */
+               for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
+                       if ((*i) == route || (*i)->solo_isolated() || (*i)->is_master() || (*i)->is_monitor() || (*i)->is_hidden()) {
+                               continue;
+                       } 
+                       (*i)->set_solo (false, this);
+               }
+       }
 
        solo_update_disabled = true;
         
-        RouteList uninvolved;
+       RouteList uninvolved;
         
        for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
                bool via_sends_only;
-                bool in_signal_flow;
+               bool in_signal_flow;
 
                if ((*i) == route || (*i)->solo_isolated() || (*i)->is_master() || (*i)->is_monitor() || (*i)->is_hidden()) {
                        continue;
                } 
 
-                in_signal_flow = false;
+               in_signal_flow = false;
 
-                if ((*i)->feeds (route, &via_sends_only)) {
+               if ((*i)->feeds (route, &via_sends_only)) {
                        if (!via_sends_only) {
-                                if (!route->soloed_by_others_upstream()) {
-                                        (*i)->mod_solo_by_others_downstream (delta);
-                                }
-                                in_signal_flow = true;
+                               if (!route->soloed_by_others_upstream()) {
+                                       (*i)->mod_solo_by_others_downstream (delta);
+                               }
+                               in_signal_flow = true;
                        }
                } 
                 
-                if (route->feeds (*i, &via_sends_only)) {
-                        (*i)->mod_solo_by_others_upstream (delta);
-                        in_signal_flow = true;
-                }
+               if (route->feeds (*i, &via_sends_only)) {
+                       (*i)->mod_solo_by_others_upstream (delta);
+                       in_signal_flow = true;
+               }
 
-                if (!in_signal_flow) {
-                        uninvolved.push_back (*i);
-                }
+               if (!in_signal_flow) {
+                       uninvolved.push_back (*i);
+               }
        }
 
        solo_update_disabled = false;
        update_route_solo_state (r);
 
-        /* now notify that the mute state of the routes not involved in the signal
-           pathway of the just-solo-changed route may have altered.
-        */
+       /* now notify that the mute state of the routes not involved in the signal
+          pathway of the just-solo-changed route may have altered.
+       */
 
-        for (RouteList::iterator i = uninvolved.begin(); i != uninvolved.end(); ++i) {
-                (*i)->mute_changed (this);
-        }
+       for (RouteList::iterator i = uninvolved.begin(); i != uninvolved.end(); ++i) {
+               (*i)->mute_changed (this);
+       }
 
        SoloChanged (); /* EMIT SIGNAL */
        set_dirty();
@@ -2289,8 +2330,8 @@ Session::update_route_solo_state (boost::shared_ptr<RouteList> r)
        /* now figure out if anything that matters is soloed (or is "listening")*/
 
        bool something_soloed = false;
-        uint32_t listeners = 0;
-        uint32_t isolated = 0;
+       uint32_t listeners = 0;
+       uint32_t isolated = 0;
 
        if (!r) {
                r = routes.reader();
@@ -2301,36 +2342,36 @@ Session::update_route_solo_state (boost::shared_ptr<RouteList> r)
                        something_soloed = true;
                }
 
-                if (!(*i)->is_hidden() && (*i)->listening()) {
-                        if (Config->get_solo_control_is_listen_control()) {
-                                listeners++;
-                        } else {
-                                (*i)->set_listen (false, this);
-                        }
-                }
+               if (!(*i)->is_hidden() && (*i)->listening_via_monitor()) {
+                       if (Config->get_solo_control_is_listen_control()) {
+                               listeners++;
+                       } else {
+                               (*i)->set_listen (false, this);
+                       }
+               }
 
-                if ((*i)->solo_isolated()) {
-                        isolated++;
-                }
+               if ((*i)->solo_isolated()) {
+                       isolated++;
+               }
        }
 
-        if (something_soloed != _non_soloed_outs_muted) {
-                _non_soloed_outs_muted = something_soloed;
-                SoloActive (_non_soloed_outs_muted); /* EMIT SIGNAL */
-        }
+       if (something_soloed != _non_soloed_outs_muted) {
+               _non_soloed_outs_muted = something_soloed;
+               SoloActive (_non_soloed_outs_muted); /* EMIT SIGNAL */
+       }
 
-        _listen_cnt = listeners;
+       _listen_cnt = listeners;
 
-        if (isolated != _solo_isolated_cnt) {
-                _solo_isolated_cnt = isolated;
-                IsolatedChanged (); /* EMIT SIGNAL */
-        }
+       if (isolated != _solo_isolated_cnt) {
+               _solo_isolated_cnt = isolated;
+               IsolatedChanged (); /* EMIT SIGNAL */
+       }
 }
 
 boost::shared_ptr<RouteList> 
 Session::get_routes_with_internal_returns() const
 {
-       shared_ptr<RouteList> r = routes.reader ();
+       boost::shared_ptr<RouteList> r = routes.reader ();
        boost::shared_ptr<RouteList> rl (new RouteList);
 
        for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
@@ -2344,25 +2385,25 @@ Session::get_routes_with_internal_returns() const
 bool
 Session::io_name_is_legal (const std::string& name)
 {
-        shared_ptr<RouteList> r = routes.reader ();
+       boost::shared_ptr<RouteList> r = routes.reader ();
         
-        for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
-                if ((*i)->name() == name) {
-                        return false;
-                }
+       for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
+               if ((*i)->name() == name) {
+                       return false;
+               }
                 
-                if ((*i)->has_io_processor_named (name)) {
-                        return false;
-                }
-        }
+               if ((*i)->has_io_processor_named (name)) {
+                       return false;
+               }
+       }
         
-        return true;
+       return true;
 }
 
-shared_ptr<Route>
+boost::shared_ptr<Route>
 Session::route_by_name (string name)
 {
-       shared_ptr<RouteList> r = routes.reader ();
+       boost::shared_ptr<RouteList> r = routes.reader ();
 
        for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
                if ((*i)->name() == name) {
@@ -2370,13 +2411,13 @@ Session::route_by_name (string name)
                }
        }
 
-       return shared_ptr<Route> ((Route*) 0);
+       return boost::shared_ptr<Route> ((Route*) 0);
 }
 
-shared_ptr<Route>
+boost::shared_ptr<Route>
 Session::route_by_id (PBD::ID id)
 {
-       shared_ptr<RouteList> r = routes.reader ();
+       boost::shared_ptr<RouteList> r = routes.reader ();
 
        for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
                if ((*i)->id() == id) {
@@ -2384,13 +2425,13 @@ Session::route_by_id (PBD::ID id)
                }
        }
 
-       return shared_ptr<Route> ((Route*) 0);
+       return boost::shared_ptr<Route> ((Route*) 0);
 }
 
-shared_ptr<Route>
+boost::shared_ptr<Route>
 Session::route_by_remote_id (uint32_t id)
 {
-       shared_ptr<RouteList> r = routes.reader ();
+       boost::shared_ptr<RouteList> r = routes.reader ();
 
        for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
                if ((*i)->remote_control_id() == id) {
@@ -2398,67 +2439,88 @@ Session::route_by_remote_id (uint32_t id)
                }
        }
 
-       return shared_ptr<Route> ((Route*) 0);
+       return boost::shared_ptr<Route> ((Route*) 0);
 }
 
-/** If either end of the session range location marker lies inside the current
- *  session extent, move it to the corresponding session extent.
+void
+Session::playlist_region_added (boost::weak_ptr<Region> w)
+{
+       boost::shared_ptr<Region> r = w.lock ();
+       if (!r) {
+               return;
+       }
+
+       /* These are the operations that are currently in progress... */
+       list<GQuark> curr = _current_trans_quarks;
+       curr.sort ();
+
+       /* ...and these are the operations during which we want to update
+          the session range location markers.
+       */
+       list<GQuark> ops;
+       ops.push_back (Operations::capture);
+       ops.push_back (Operations::paste);
+       ops.push_back (Operations::duplicate_region);
+       ops.push_back (Operations::insert_file);
+       ops.push_back (Operations::insert_region);
+       ops.push_back (Operations::drag_region_brush);
+       ops.push_back (Operations::region_drag);
+       ops.push_back (Operations::selection_grab);
+       ops.push_back (Operations::region_fill);
+       ops.push_back (Operations::fill_selection);
+       ops.push_back (Operations::create_region);
+       ops.sort ();
+
+       /* See if any of the current operations match the ones that we want */
+       list<GQuark> in;
+       set_intersection (_current_trans_quarks.begin(), _current_trans_quarks.end(), ops.begin(), ops.end(), back_inserter (in));
+
+       /* If so, update the session range markers */
+       if (!in.empty ()) {
+               maybe_update_session_range (r->position (), r->last_frame ());
+       }
+}
+
+/** Update the session range markers if a is before the current start or
+ *  b is after the current end.
  */
 void
-Session::update_session_range_location_marker ()
+Session::maybe_update_session_range (framepos_t a, framepos_t b)
 {
        if (_state_of_the_state & Loading) {
                return;
        }
 
-       pair<nframes_t, nframes_t> const ext = get_extent ();
-
        if (_session_range_location == 0) {
-               /* we don't have a session range yet; use this one (provided it is valid) */
-               if (ext.first != max_frames) {
-                       add_session_range_location (ext.first, ext.second);
-               }
+               
+               add_session_range_location (a, b);
+               
        } else {
-               /* update the existing session range */
-               if (ext.first < _session_range_location->start()) {
-                       _session_range_location->set_start (ext.first);
-                       set_dirty ();
-               }
                
-               if (ext.second > _session_range_location->end()) {
-                       _session_range_location->set_end (ext.second);
-                       set_dirty ();
+               if (a < _session_range_location->start()) {
+                       _session_range_location->set_start (a);
                }
                
+               if (b > _session_range_location->end()) {
+                       _session_range_location->set_end (b);
+               }
        }
 }
 
-/** @return Extent of the session's contents; if the session is empty, the first value of
- *  the pair will equal max_frames.
- */
-pair<nframes_t, nframes_t>
-Session::get_extent () const
+void
+Session::playlist_ranges_moved (list<Evoral::RangeMove<framepos_t> > const & ranges)
 {
-       pair<nframes_t, nframes_t> ext (max_frames, 0);
-       
-       boost::shared_ptr<RouteList> rl = routes.reader ();
-       for (RouteList::iterator i = rl->begin(); i != rl->end(); ++i) {
-               boost::shared_ptr<Track> tr = boost::dynamic_pointer_cast<Track> (*i);
-               if (!tr || tr->destructive()) {
-                       // ignore tape tracks when getting extents
-                       continue;
-               }
-
-               pair<nframes_t, nframes_t> e = tr->playlist()->get_extent ();
-               if (e.first < ext.first) {
-                       ext.first = e.first;
-               }
-               if (e.second > ext.second) {
-                       ext.second = e.second;
-               }
+       for (list<Evoral::RangeMove<framepos_t> >::const_iterator i = ranges.begin(); i != ranges.end(); ++i) {
+               maybe_update_session_range (i->to, i->to + i->length);
        }
+}
 
-       return ext;
+void
+Session::playlist_regions_extended (list<Evoral::Range<framepos_t> > const & ranges)
+{
+       for (list<Evoral::Range<framepos_t> >::const_iterator i = ranges.begin(); i != ranges.end(); ++i) {
+               maybe_update_session_range (i->from, i->to);
+       }
 }
 
 /* Region management */
@@ -2466,7 +2528,7 @@ Session::get_extent () const
 boost::shared_ptr<Region>
 Session::find_whole_file_parent (boost::shared_ptr<Region const> child) const
 {
-        const RegionFactory::RegionMap& regions (RegionFactory::regions());
+       const RegionFactory::RegionMap& regions (RegionFactory::regions());
        RegionFactory::RegionMap::const_iterator i;
        boost::shared_ptr<Region> region;
 
@@ -2490,48 +2552,48 @@ Session::find_whole_file_parent (boost::shared_ptr<Region const> child) const
 int
 Session::destroy_sources (list<boost::shared_ptr<Source> > srcs)
 {
-        set<boost::shared_ptr<Region> > relevant_regions;
+       set<boost::shared_ptr<Region> > relevant_regions;
 
        for (list<boost::shared_ptr<Source> >::iterator s = srcs.begin(); s != srcs.end(); ++s) {
-                RegionFactory::get_regions_using_source (*s, relevant_regions);
+               RegionFactory::get_regions_using_source (*s, relevant_regions);
        }
 
-        cerr << "There are " << relevant_regions.size() << " using " << srcs.size() << " sources" << endl;
+       cerr << "There are " << relevant_regions.size() << " using " << srcs.size() << " sources" << endl;
 
-        for (set<boost::shared_ptr<Region> >::iterator r = relevant_regions.begin(); r != relevant_regions.end(); ) {
-                set<boost::shared_ptr<Region> >::iterator tmp;
+       for (set<boost::shared_ptr<Region> >::iterator r = relevant_regions.begin(); r != relevant_regions.end(); ) {
+               set<boost::shared_ptr<Region> >::iterator tmp;
 
-                tmp = r;
-                ++tmp;
+               tmp = r;
+               ++tmp;
 
-                cerr << "Cleanup " << (*r)->name() << " UC = " << (*r).use_count() << endl;
+               cerr << "Cleanup " << (*r)->name() << " UC = " << (*r).use_count() << endl;
 
-                playlists->destroy_region (*r);
-                RegionFactory::map_remove (*r);
+               playlists->destroy_region (*r);
+               RegionFactory::map_remove (*r);
 
-                (*r)->drop_sources ();
-                (*r)->drop_references ();
+               (*r)->drop_sources ();
+               (*r)->drop_references ();
 
-                cerr << "\tdone UC = " << (*r).use_count() << endl;
+               cerr << "\tdone UC = " << (*r).use_count() << endl;
 
-                relevant_regions.erase (r);
+               relevant_regions.erase (r);
 
-                r = tmp;
-        }
+               r = tmp;
+       }
 
        for (list<boost::shared_ptr<Source> >::iterator s = srcs.begin(); s != srcs.end(); ) {
                 
-                {
-                        Glib::Mutex::Lock ls (source_lock);
-                        /* remove from the main source list */
-                        sources.erase ((*s)->id());
-                }
+               {
+                       Glib::Mutex::Lock ls (source_lock);
+                       /* remove from the main source list */
+                       sources.erase ((*s)->id());
+               }
 
-                (*s)->mark_for_remove ();
-                (*s)->drop_references ();
+               (*s)->mark_for_remove ();
+               (*s)->drop_references ();
 
-                s = srcs.erase (s);
-        }
+               s = srcs.erase (s);
+       }
 
        return 0;
 }
@@ -2581,23 +2643,29 @@ Session::add_source (boost::shared_ptr<Source> source)
 
        if (result.second) {
 
-                /* yay, new source */
+               /* yay, new source */
 
                set_dirty();
 
-                boost::shared_ptr<AudioFileSource> afs;
+               boost::shared_ptr<AudioFileSource> afs;
                 
-                if ((afs = boost::dynamic_pointer_cast<AudioFileSource>(source)) != 0) {
-                        if (Config->get_auto_analyse_audio()) {
-                                Analyser::queue_source_for_analysis (source, false);
-                        }
-                }
-        }
+               if ((afs = boost::dynamic_pointer_cast<AudioFileSource>(source)) != 0) {
+                       if (Config->get_auto_analyse_audio()) {
+                               Analyser::queue_source_for_analysis (source, false);
+                       }
+               }
+
+               source->DropReferences.connect_same_thread (*this, boost::bind (&Session::remove_source, this, boost::weak_ptr<Source> (source)));
+       }
 }
 
 void
 Session::remove_source (boost::weak_ptr<Source> src)
 {
+       if (_state_of_the_state & Deletion) {
+               return;
+       }
+       
        SourceMap::iterator i;
        boost::shared_ptr<Source> source = src.lock();
 
@@ -2638,12 +2706,11 @@ Session::source_by_id (const PBD::ID& id)
 }
 
 boost::shared_ptr<Source>
-Session::source_by_path_and_channel (const Glib::ustring& path, uint16_t chn)
+Session::source_by_path_and_channel (const string& path, uint16_t chn)
 {
        Glib::Mutex::Lock lm (source_lock);
 
        for (SourceMap::iterator i = sources.begin(); i != sources.end(); ++i) {
-               cerr << "comparing " << path << " with " << i->second->name() << endl;
                boost::shared_ptr<AudioFileSource> afs
                        = boost::dynamic_pointer_cast<AudioFileSource>(i->second);
 
@@ -2654,6 +2721,24 @@ Session::source_by_path_and_channel (const Glib::ustring& path, uint16_t chn)
        return boost::shared_ptr<Source>();
 }
 
+uint32_t
+Session::count_sources_by_origin (const string& path)
+{
+       uint32_t cnt = 0;
+       Glib::Mutex::Lock lm (source_lock);
+
+       for (SourceMap::iterator i = sources.begin(); i != sources.end(); ++i) {
+               boost::shared_ptr<FileSource> fs
+                       = boost::dynamic_pointer_cast<FileSource>(i->second);
+
+               if (fs && fs->origin() == path) {
+                       ++cnt;
+               }
+       }
+
+       return cnt;
+}
+
 
 string
 Session::change_source_path_by_name (string path, string oldname, string newname, bool destructive)
@@ -2673,18 +2758,12 @@ Session::change_source_path_by_name (string path, string oldname, string newname
                    the task here is to replace NAME with the new name.
                */
 
-               /* find last slash */
-
                string dir;
                string prefix;
-               string::size_type slash;
                string::size_type dash;
 
-               if ((slash = path.find_last_of ('/')) == string::npos) {
-                       return "";
-               }
-
-               dir = path.substr (0, slash+1);
+               dir = Glib::path_get_dirname (path);
+               path = Glib::path_get_basename (path);
 
                /* '-' is not a legal character for the NAME part of the path */
 
@@ -2692,13 +2771,13 @@ Session::change_source_path_by_name (string path, string oldname, string newname
                        return "";
                }
 
-               prefix = path.substr (slash+1, dash-(slash+1));
+               prefix = path.substr (0, dash);
 
-               path = dir;
                path += prefix;
                path += '-';
                path += new_legalized;
-               path += ".wav";  /* XXX gag me with a spoon */
+               path += native_header_format_extension (config.get_native_file_header_format(), DataType::AUDIO);
+               path = Glib::build_filename (dir, path);
 
        } else {
 
@@ -2711,17 +2790,11 @@ Session::change_source_path_by_name (string path, string oldname, string newname
 
                string dir;
                string suffix;
-               string::size_type slash;
                string::size_type dash;
                string::size_type postfix;
 
-               /* find last slash */
-
-               if ((slash = path.find_last_of ('/')) == string::npos) {
-                       return "";
-               }
-
-               dir = path.substr (0, slash+1);
+               dir = Glib::path_get_dirname (path);
+               path = Glib::path_get_basename (path);
 
                /* '-' is not a legal character for the NAME part of the path */
 
@@ -2751,19 +2824,21 @@ Session::change_source_path_by_name (string path, string oldname, string newname
 
                for (uint32_t cnt = 1; cnt <= limit; ++cnt) {
 
-                       snprintf (buf, sizeof(buf), "%s%s-%u%s", dir.c_str(), newname.c_str(), cnt, suffix.c_str());
+                       snprintf (buf, sizeof(buf), "%s-%u%s", newname.c_str(), cnt, suffix.c_str());
 
-                       if (access (buf, F_OK) != 0) {
-                               path = buf;
+                       if (!matching_unsuffixed_filename_exists_in (dir, buf)) {
+                               path = Glib::build_filename (dir, buf);
                                break;
                        }
+
                        path = "";
                }
 
-               if (path == "") {
-                       error << "FATAL ERROR! Could not find a " << endl;
+               if (path.empty()) {
+                       fatal << string_compose (_("FATAL ERROR! Could not find a suitable version of %1 for a rename"),
+                                                newname) << endl;
+                       /*NOTREACHED*/
                }
-
        }
 
        return path;
@@ -2794,11 +2869,11 @@ Session::new_source_path_from_name (DataType type, const string& name)
        return p.to_string();
 }
 
-Glib::ustring
-Session::peak_path (Glib::ustring base) const
+string
+Session::peak_path (string base) const
 {
        sys::path peakfile_path(_session_dir->peak_path());
-       peakfile_path /= basename_nosuffix (base) + peakfile_suffix;
+       peakfile_path /= base + peakfile_suffix;
        return peakfile_path.to_string();
 }
 
@@ -2806,11 +2881,11 @@ Session::peak_path (Glib::ustring base) const
 string
 Session::new_audio_source_name (const string& base, uint32_t nchan, uint32_t chan, bool destructive)
 {
-       string spath;
        uint32_t cnt;
        char buf[PATH_MAX+1];
        const uint32_t limit = 10000;
        string legalized;
+       string ext = native_header_format_extension (config.get_native_file_header_format(), DataType::AUDIO);
 
        buf[0] = '\0';
        legalized = legalize_for_path (base);
@@ -2823,55 +2898,58 @@ Session::new_audio_source_name (const string& base, uint32_t nchan, uint32_t cha
 
                for (i = session_dirs.begin(); i != session_dirs.end(); ++i) {
 
-                       SessionDirectory sdir((*i).path);
-
-                       spath = sdir.sound_path().to_string();
-
                        if (destructive) {
 
                                if (nchan < 2) {
-                                       snprintf (buf, sizeof(buf), "%s/T%04d-%s.wav",
-                                                       spath.c_str(), cnt, legalized.c_str());
+                                       snprintf (buf, sizeof(buf), "T%04d-%s%s",
+                                                 cnt, legalized.c_str(), ext.c_str());
                                } else if (nchan == 2) {
                                        if (chan == 0) {
-                                               snprintf (buf, sizeof(buf), "%s/T%04d-%s%%L.wav",
-                                                               spath.c_str(), cnt, legalized.c_str());
+                                               snprintf (buf, sizeof(buf), "T%04d-%s%%L%s",
+                                                         cnt, legalized.c_str(), ext.c_str());
                                        } else {
-                                               snprintf (buf, sizeof(buf), "%s/T%04d-%s%%R.wav",
-                                                               spath.c_str(), cnt, legalized.c_str());
+                                               snprintf (buf, sizeof(buf), "T%04d-%s%%R%s",
+                                                         cnt, legalized.c_str(), ext.c_str());
                                        }
                                } else if (nchan < 26) {
-                                       snprintf (buf, sizeof(buf), "%s/T%04d-%s%%%c.wav",
-                                                       spath.c_str(), cnt, legalized.c_str(), 'a' + chan);
+                                       snprintf (buf, sizeof(buf), "T%04d-%s%%%c%s",
+                                                 cnt, legalized.c_str(), 'a' + chan, ext.c_str());
                                } else {
-                                       snprintf (buf, sizeof(buf), "%s/T%04d-%s.wav",
-                                                       spath.c_str(), cnt, legalized.c_str());
+                                       snprintf (buf, sizeof(buf), "T%04d-%s%s",
+                                                 cnt, legalized.c_str(), ext.c_str());
                                }
 
                        } else {
 
-                               spath += '/';
-                               spath += legalized;
-
                                if (nchan < 2) {
-                                       snprintf (buf, sizeof(buf), "%s-%u.wav", spath.c_str(), cnt);
+                                       snprintf (buf, sizeof(buf), "%s-%u%s", legalized.c_str(), cnt, ext.c_str());
                                } else if (nchan == 2) {
                                        if (chan == 0) {
-                                               snprintf (buf, sizeof(buf), "%s-%u%%L.wav", spath.c_str(), cnt);
+                                               snprintf (buf, sizeof(buf), "%s-%u%%L%s", legalized.c_str(), cnt, ext.c_str());
                                        } else {
-                                               snprintf (buf, sizeof(buf), "%s-%u%%R.wav", spath.c_str(), cnt);
+                                               snprintf (buf, sizeof(buf), "%s-%u%%R%s", legalized.c_str(), cnt, ext.c_str());
                                        }
                                } else if (nchan < 26) {
-                                       snprintf (buf, sizeof(buf), "%s-%u%%%c.wav", spath.c_str(), cnt, 'a' + chan);
+                                       snprintf (buf, sizeof(buf), "%s-%u%%%c%s", legalized.c_str(), cnt, 'a' + chan, ext.c_str());
                                } else {
-                                       snprintf (buf, sizeof(buf), "%s-%u.wav", spath.c_str(), cnt);
+                                       snprintf (buf, sizeof(buf), "%s-%u%s", legalized.c_str(), cnt, ext.c_str());
                                }
                        }
 
-                       if (sys::exists(buf)) {
+                       SessionDirectory sdir((*i).path);
+
+                       string spath = sdir.sound_path().to_string();
+
+                       /* note that we search *without* the extension so that
+                          we don't end up both "Audio 1-1.wav" and "Audio 1-1.caf" 
+                          in the event that this new name is required for
+                          a file format change.
+                       */
+
+                       if (matching_unsuffixed_filename_exists_in (spath, buf)) {
                                existing++;
+                               break;
                        }
-
                }
 
                if (existing == 0) {
@@ -2886,8 +2964,8 @@ Session::new_audio_source_name (const string& base, uint32_t nchan, uint32_t cha
                        throw failed_constructor();
                }
        }
-
-       return Glib::path_get_basename(buf);
+        
+       return Glib::path_get_basename (buf);
 }
 
 /** Create a new within-session audio source */
@@ -2898,7 +2976,7 @@ Session::create_audio_source_for_session (size_t n_chans, string const & n, uint
        const string path    = new_source_path_from_name(DataType::AUDIO, name);
 
        return boost::dynamic_pointer_cast<AudioFileSource> (
-               SourceFactory::createWritable (DataType::AUDIO, *this, path, destructive, frame_rate()));
+               SourceFactory::createWritable (DataType::AUDIO, *this, path, string(), destructive, frame_rate()));
 }
 
 /** Return a unique name based on \a base for a new internal MIDI source */
@@ -2954,28 +3032,28 @@ Session::new_midi_source_name (const string& base)
 boost::shared_ptr<MidiSource>
 Session::create_midi_source_for_session (Track* track, string const & n)
 {
-        /* try to use the existing write source for the track, to keep numbering sane 
-         */
+       /* try to use the existing write source for the track, to keep numbering sane 
+        */
 
-        if (track) {
-                /*MidiTrack* mt = dynamic_cast<Track*> (track);
-                assert (mt);
-                */
+       if (track) {
+               /*MidiTrack* mt = dynamic_cast<Track*> (track);
+                 assert (mt);
+               */
 
-                list<boost::shared_ptr<Source> > l = track->steal_write_sources ();
+               list<boost::shared_ptr<Source> > l = track->steal_write_sources ();
                 
-                if (!l.empty()) {
-                        assert (boost::dynamic_pointer_cast<MidiSource> (l.front()));
-                        return boost::dynamic_pointer_cast<MidiSource> (l.front());
-                }
-        }
+               if (!l.empty()) {
+                       assert (boost::dynamic_pointer_cast<MidiSource> (l.front()));
+                       return boost::dynamic_pointer_cast<MidiSource> (l.front());
+               }
+       }
 
        const string name = new_midi_source_name (n);
        const string path = new_source_path_from_name (DataType::MIDI, name);
 
        return boost::dynamic_pointer_cast<SMFSource> (
-                       SourceFactory::createWritable (
-                                       DataType::MIDI, *this, path, false, frame_rate()));
+               SourceFactory::createWritable (
+                       DataType::MIDI, *this, path, string(), false, frame_rate()));
 }
 
 
@@ -3061,49 +3139,13 @@ Session::cancel_audition ()
 bool
 Session::RoutePublicOrderSorter::operator() (boost::shared_ptr<Route> a, boost::shared_ptr<Route> b)
 {
-        if (a->is_monitor()) { 
-                return true;
-        }
-        if (b->is_monitor()) {
-                return false;
-        }
-       return a->order_key(N_("signal")) < b->order_key(N_("signal"));
-}
-
-void
-Session::remove_empty_sounds ()
-{
-       vector<string> audio_filenames;
-
-       get_files_in_directory (_session_dir->sound_path(), audio_filenames);
-
-       Glib::Mutex::Lock lm (source_lock);
-
-       TapeFileMatcher tape_file_matcher;
-
-       remove_if (audio_filenames.begin(), audio_filenames.end(),
-                  boost::bind (&TapeFileMatcher::matches, &tape_file_matcher, _1));
-       
-       for (vector<string>::iterator i = audio_filenames.begin(); i != audio_filenames.end(); ++i) {
-
-               sys::path audio_file_path (_session_dir->sound_path());
-
-               audio_file_path /= *i;
-
-               if (AudioFileSource::is_empty (*this, audio_file_path.to_string())) {
-
-                       try
-                       {
-                               sys::remove (audio_file_path);
-                               const string peakfile = peak_path (audio_file_path.to_string());
-                               sys::remove (peakfile);
-                       }
-                       catch (const sys::filesystem_error& err)
-                       {
-                               error << err.what() << endmsg;
-                       }
-               }
+       if (a->is_monitor()) { 
+               return true;
        }
+       if (b->is_monitor()) {
+               return false;
+       }
+       return a->order_key(N_("signal")) < b->order_key(N_("signal"));
 }
 
 bool
@@ -3149,7 +3191,7 @@ Session::graph_reordered ()
        }
 }
 
-nframes_t
+framecnt_t
 Session::available_capture_duration ()
 {
        float sample_bytes_on_disk = 4.0; // keep gcc happy
@@ -3177,15 +3219,15 @@ Session::available_capture_duration ()
 
        double scale = 4096.0 / sample_bytes_on_disk;
 
-       if (_total_free_4k_blocks * scale > (double) max_frames) {
-               return max_frames;
+       if (_total_free_4k_blocks * scale > (double) max_framecnt) {
+               return max_framecnt;
        }
-
-       return (nframes_t) floor (_total_free_4k_blocks * scale);
+        
+       return (framecnt_t) floor (_total_free_4k_blocks * scale);
 }
 
 void
-Session::add_bundle (shared_ptr<Bundle> bundle)
+Session::add_bundle (boost::shared_ptr<Bundle> bundle)
 {
        {
                RCUWriter<BundleList> writer (_bundles);
@@ -3199,7 +3241,7 @@ Session::add_bundle (shared_ptr<Bundle> bundle)
 }
 
 void
-Session::remove_bundle (shared_ptr<Bundle> bundle)
+Session::remove_bundle (boost::shared_ptr<Bundle> bundle)
 {
        bool removed = false;
 
@@ -3221,7 +3263,7 @@ Session::remove_bundle (shared_ptr<Bundle> bundle)
        set_dirty();
 }
 
-shared_ptr<Bundle>
+boost::shared_ptr<Bundle>
 Session::bundle_by_name (string name) const
 {
        boost::shared_ptr<BundleList> b = _bundles.reader ();
@@ -3242,16 +3284,26 @@ Session::tempo_map_changed (const PropertyChange&)
 
        playlists->update_after_tempo_map_change ();
 
+       _locations->apply (*this, &Session::update_locations_after_tempo_map_change);
+       
        set_dirty ();
 }
 
+void
+Session::update_locations_after_tempo_map_change (Locations::LocationList& loc)
+{
+       for (Locations::LocationList::iterator i = loc.begin(); i != loc.end(); ++i) {
+               (*i)->recompute_frames_from_bbt ();
+       }
+}
+
 /** Ensures that all buffers (scratch, send, silent, etc) are allocated for
  * the given count with the current block size.
  */
 void
 Session::ensure_buffers (ChanCount howmany)
 {
-        BufferManager::ensure_buffers (howmany);
+       BufferManager::ensure_buffers (howmany);
 }
 
 void
@@ -3362,24 +3414,24 @@ void
 Session::unmark_send_id (uint32_t id)
 {
        if (id < send_bitset.size()) {
-                send_bitset[id] = false;
-        }
+               send_bitset[id] = false;
+       }
 }
 
 void
 Session::unmark_return_id (uint32_t id)
 {
        if (id < return_bitset.size()) {
-                return_bitset[id] = false;
-        }
+               return_bitset[id] = false;
+       }
 }
 
 void
 Session::unmark_insert_id (uint32_t id)
 {
        if (id < insert_bitset.size()) {
-                insert_bitset[id] = false;
-        }
+               insert_bitset[id] = false;
+       }
 }
 
 
@@ -3439,7 +3491,12 @@ Session::reset_native_file_format ()
        for (RouteList::iterator i = rl->begin(); i != rl->end(); ++i) {
                boost::shared_ptr<Track> tr = boost::dynamic_pointer_cast<Track> (*i);
                if (tr) {
+                       /* don't save state as we do this, there's no point
+                        */
+
+                       _state_of_the_state = StateOfTheState (_state_of_the_state|InCleanup);
                        tr->reset_write_sources (false);
+                       _state_of_the_state = StateOfTheState (_state_of_the_state & ~InCleanup);
                }
        }
 }
@@ -3447,7 +3504,7 @@ Session::reset_native_file_format ()
 bool
 Session::route_name_unique (string n) const
 {
-       shared_ptr<RouteList> r = routes.reader ();
+       boost::shared_ptr<RouteList> r = routes.reader ();
 
        for (RouteList::const_iterator i = r->begin(); i != r->end(); ++i) {
                if ((*i)->name() == n) {
@@ -3475,7 +3532,7 @@ Session::route_name_internal (string n) const
 int
 Session::freeze_all (InterThreadInfo& itt)
 {
-       shared_ptr<RouteList> r = routes.reader ();
+       boost::shared_ptr<RouteList> r = routes.reader ();
 
        for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
 
@@ -3493,7 +3550,7 @@ Session::freeze_all (InterThreadInfo& itt)
 }
 
 boost::shared_ptr<Region>
-Session::write_one_track (AudioTrack& track, nframes_t start, nframes_t end,
+Session::write_one_track (AudioTrack& track, framepos_t start, framepos_t end,
                          bool /*overwrite*/, vector<boost::shared_ptr<Source> >& srcs,
                          InterThreadInfo& itt, bool enable_processing)
 {
@@ -3502,14 +3559,17 @@ Session::write_one_track (AudioTrack& track, nframes_t start, nframes_t end,
        boost::shared_ptr<AudioFileSource> fsource;
        uint32_t x;
        char buf[PATH_MAX+1];
-       ChanCount nchans(track.n_channels());
-       nframes_t position;
-       nframes_t this_chunk;
-       nframes_t to_do;
+       ChanCount diskstream_channels (track.n_channels());
+       framepos_t position;
+       framecnt_t this_chunk;
+       framepos_t to_do;
        BufferSet buffers;
        SessionDirectory sdir(get_best_session_directory_for_new_source ());
        const string sound_dir = sdir.sound_path().to_string();
-       nframes_t len = end - start;
+       framepos_t len = end - start;
+       bool need_block_size_reset = false;
+       string ext;
+       ChanCount const max_proc = track.max_processor_streams ();
 
        if (end <= start) {
                error << string_compose (_("Cannot write a range where end <= start (e.g. %1 <= %2)"),
@@ -3517,7 +3577,7 @@ Session::write_one_track (AudioTrack& track, nframes_t start, nframes_t end,
                return result;
        }
 
-       const nframes_t chunk_size = (256 * 1024)/4;
+       const framecnt_t chunk_size = (256 * 1024)/4;
 
        // block all process callback handling
 
@@ -3535,10 +3595,12 @@ Session::write_one_track (AudioTrack& track, nframes_t start, nframes_t end,
                goto out;
        }
 
-       for (uint32_t chan_n=0; chan_n < nchans.n_audio(); ++chan_n) {
+       ext = native_header_format_extension (config.get_native_file_header_format(), DataType::AUDIO);
+
+       for (uint32_t chan_n = 0; chan_n < diskstream_channels.n_audio(); ++chan_n) {
 
                for (x = 0; x < 99999; ++x) {
-                       snprintf (buf, sizeof(buf), "%s/%s-%d-bounce-%" PRIu32 ".wav", sound_dir.c_str(), playlist->name().c_str(), chan_n, x+1);
+                       snprintf (buf, sizeof(buf), "%s/%s-%d-bounce-%" PRIu32 "%s", sound_dir.c_str(), playlist->name().c_str(), chan_n, x+1, ext.c_str());
                        if (access (buf, F_OK) != 0) {
                                break;
                        }
@@ -3551,7 +3613,7 @@ Session::write_one_track (AudioTrack& track, nframes_t start, nframes_t end,
 
                try {
                        fsource = boost::dynamic_pointer_cast<AudioFileSource> (
-                               SourceFactory::createWritable (DataType::AUDIO, *this, buf, false, frame_rate()));
+                               SourceFactory::createWritable (DataType::AUDIO, *this, buf, string(), false, frame_rate()));
                }
 
                catch (failed_constructor& err) {
@@ -3562,16 +3624,21 @@ Session::write_one_track (AudioTrack& track, nframes_t start, nframes_t end,
                srcs.push_back (fsource);
        }
 
+       /* tell redirects that care that we are about to use a much larger blocksize */
+        
+       need_block_size_reset = true;
+       track.set_block_size (chunk_size);
+
        /* XXX need to flush all redirects */
 
        position = start;
        to_do = len;
 
        /* create a set of reasonably-sized buffers */
-       buffers.ensure_buffers(DataType::AUDIO, nchans.n_audio(), chunk_size);
-       buffers.set_count(nchans);
+       buffers.ensure_buffers (DataType::AUDIO, max_proc.n_audio(), chunk_size);
+       buffers.set_count (max_proc);
 
-       for (vector<boost::shared_ptr<Source> >::iterator src=srcs.begin(); src != srcs.end(); ++src) {
+       for (vector<boost::shared_ptr<Source> >::iterator src = srcs.begin(); src != srcs.end(); ++src) {
                boost::shared_ptr<AudioFileSource> afs = boost::dynamic_pointer_cast<AudioFileSource>(*src);
                if (afs)
                        afs->prepare_for_peakfile_writes ();
@@ -3652,6 +3719,11 @@ Session::write_one_track (AudioTrack& track, nframes_t start, nframes_t end,
                }
        }
 
+
+       if (need_block_size_reset) {
+               track.set_block_size (get_block_size());
+       }
+        
        unblock_processing ();
 
        return result;
@@ -3660,65 +3732,38 @@ Session::write_one_track (AudioTrack& track, nframes_t start, nframes_t end,
 gain_t*
 Session::gain_automation_buffer() const
 {
-        return ProcessThread::gain_automation_buffer ();
+       return ProcessThread::gain_automation_buffer ();
 }
 
 pan_t**
 Session::pan_automation_buffer() const
 {
-        return ProcessThread::pan_automation_buffer ();
+       return ProcessThread::pan_automation_buffer ();
 }
 
 BufferSet&
 Session::get_silent_buffers (ChanCount count)
 {
-        return ProcessThread::get_silent_buffers (count);
-#if 0
-       assert(_silent_buffers->available() >= count);
-       _silent_buffers->set_count(count);
-
-       for (DataType::iterator t = DataType::begin(); t != DataType::end(); ++t) {
-               for (size_t i= 0; i < count.get(*t); ++i) {
-                       _silent_buffers->get(*t, i).clear();
-               }
-       }
-
-       return *_silent_buffers;
-#endif
+       return ProcessThread::get_silent_buffers (count);
 }
 
 BufferSet&
 Session::get_scratch_buffers (ChanCount count)
 {
-        return ProcessThread::get_scratch_buffers (count);
-#if 0
-       if (count != ChanCount::ZERO) {
-               assert(_scratch_buffers->available() >= count);
-               _scratch_buffers->set_count(count);
-       } else {
-               _scratch_buffers->set_count (_scratch_buffers->available());
-       }
-
-       return *_scratch_buffers;
-#endif
+       return ProcessThread::get_scratch_buffers (count);
 }
 
 BufferSet&
 Session::get_mix_buffers (ChanCount count)
 {
-        return ProcessThread::get_mix_buffers (count);
-#if 0
-       assert(_mix_buffers->available() >= count);
-       _mix_buffers->set_count(count);
-       return *_mix_buffers;
-#endif
+       return ProcessThread::get_mix_buffers (count);
 }
 
 uint32_t
 Session::ntracks () const
 {
        uint32_t n = 0;
-       shared_ptr<RouteList> r = routes.reader ();
+       boost::shared_ptr<RouteList> r = routes.reader ();
 
        for (RouteList::const_iterator i = r->begin(); i != r->end(); ++i) {
                if (boost::dynamic_pointer_cast<Track> (*i)) {
@@ -3733,7 +3778,7 @@ uint32_t
 Session::nbusses () const
 {
        uint32_t n = 0;
-       shared_ptr<RouteList> r = routes.reader ();
+       boost::shared_ptr<RouteList> r = routes.reader ();
 
        for (RouteList::const_iterator i = r->begin(); i != r->end(); ++i) {
                if (boost::dynamic_pointer_cast<Track>(*i) == 0) {
@@ -3810,22 +3855,10 @@ Session::update_have_rec_enabled_track ()
 void
 Session::listen_position_changed ()
 {
-       Placement p;
-
-       switch (Config->get_listen_position()) {
-       case AfterFaderListen:
-               p = PostFader;
-               break;
-
-       case PreFaderListen:
-               p = PreFader;
-               break;
-       }
-
        boost::shared_ptr<RouteList> r = routes.reader ();
 
        for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
-               (*i)->put_monitor_send_at (p);
+               (*i)->listen_position_changed ();
        }
 }
 
@@ -3834,11 +3867,11 @@ Session::solo_control_mode_changed ()
 {
        /* cancel all solo or all listen when solo control mode changes */
 
-        if (soloing()) {
-                set_solo (get_routes(), false);
-        } else if (listening()) {
-                set_listen (get_routes(), false);
-        }
+       if (soloing()) {
+               set_solo (get_routes(), false);
+       } else if (listening()) {
+               set_listen (get_routes(), false);
+       }
 }
 
 /** Called when anything about any of our route groups changes (membership, state etc.) */
@@ -3854,23 +3887,17 @@ Session::get_available_sync_options () const
        vector<SyncSource> ret;
        
        ret.push_back (JACK);
-
-       if (mtc_port()) {
-               ret.push_back (MTC);
-       } 
-
-       if (midi_clock_port()) {
-               ret.push_back (MIDIClock);
-       } 
+       ret.push_back (MTC);
+       ret.push_back (MIDIClock);
 
        return ret;
 }
 
 boost::shared_ptr<RouteList>
-Session::get_routes_with_regions_at (nframes64_t const p) const
+Session::get_routes_with_regions_at (framepos_t const p) const
 {
-       shared_ptr<RouteList> r = routes.reader ();
-       shared_ptr<RouteList> rl (new RouteList);
+       boost::shared_ptr<RouteList> r = routes.reader ();
+       boost::shared_ptr<RouteList> rl (new RouteList);
 
        for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
                boost::shared_ptr<Track> tr = boost::dynamic_pointer_cast<Track> (*i);
@@ -3911,41 +3938,389 @@ Session::goto_start ()
        }
 }
 
+framepos_t
+Session::current_start_frame () const
+{
+       return _session_range_location ? _session_range_location->start() : 0;
+}
+
+framepos_t
+Session::current_end_frame () const
+{
+       return _session_range_location ? _session_range_location->end() : 0;
+}
+
+void
+Session::add_session_range_location (framepos_t start, framepos_t end)
+{
+       _session_range_location = new Location (*this, start, end, _("session"), Location::IsSessionRange);
+       _locations->add (_session_range_location);
+}
+
+/** Called when one of our routes' order keys has changed */
+void
+Session::route_order_key_changed ()
+{
+       RouteOrderKeyChanged (); /* EMIT SIGNAL */
+}
+
+void
+Session::step_edit_status_change (bool yn)
+{
+       bool send = false;
+
+       bool val = false;
+       if (yn) {
+               send = (_step_editors == 0);
+               val = true;
+
+               _step_editors++;
+       } else {
+               send = (_step_editors == 1);
+               val = false;
+
+               if (_step_editors > 0) {
+                       _step_editors--;
+               }
+       }
+
+       if (send) {
+               StepEditStatusChange (val);
+       }
+}
+
+        
 void
-Session::set_session_start (nframes_t start)
+Session::start_time_changed (framepos_t old)
 {
-       if (_session_range_location) {
-               _session_range_location->set_start (start);
+       /* Update the auto loop range to match the session range
+          (unless the auto loop range has been changed by the user)
+       */
+
+       Location* s = _locations->session_range_location ();
+       if (s == 0) {
+               return;
+       }
+       
+       Location* l = _locations->auto_loop_location ();
+
+       if (l->start() == old) {
+               l->set_start (s->start(), true);
+       }
+}
+
+void
+Session::end_time_changed (framepos_t old)
+{
+       /* Update the auto loop range to match the session range
+          (unless the auto loop range has been changed by the user)
+       */
+
+       Location* s = _locations->session_range_location ();
+       if (s == 0) {
+               return;
+       }
+       
+       Location* l = _locations->auto_loop_location ();
+
+       if (l->end() == old) {
+               l->set_end (s->end(), true);
+       }
+}
+
+string
+Session::source_search_path (DataType type) const
+{
+       string search_path;
+
+       if (session_dirs.size() == 1) {
+               switch (type) {
+               case DataType::AUDIO:
+                       search_path = _session_dir->sound_path().to_string();
+                       break;
+               case DataType::MIDI:
+                       search_path = _session_dir->midi_path().to_string();
+                       break;
+               }
        } else {
-               add_session_range_location (start, start);
+               for (vector<space_and_path>::const_iterator i = session_dirs.begin(); i != session_dirs.end(); ++i) {
+                       SessionDirectory sdir (i->path);
+                       if (!search_path.empty()) {
+                               search_path += ':';
+                       } 
+                       switch (type) {
+                       case DataType::AUDIO:
+                               search_path += sdir.sound_path().to_string();
+                               break;
+                       case DataType::MIDI:
+                               search_path += sdir.midi_path().to_string();
+                               break;
+                       }
+               }
+       }
+                
+       /* now add user-specified locations
+        */
+
+       vector<string> dirs;
+
+       switch (type) {
+       case DataType::AUDIO:
+               split (config.get_audio_search_path (), dirs, ':');
+               break;
+       case DataType::MIDI:
+               split (config.get_midi_search_path (), dirs, ':');
+               break;
        }
+
+       for (vector<string>::iterator i = dirs.begin(); i != dirs.end(); ++i) {
+               search_path += ':';
+               search_path += *i;
+                        
+       }
+        
+       return search_path;
 }
-             
+
 void
-Session::set_session_end (nframes_t end)
+Session::ensure_search_path_includes (const string& path, DataType type)
 {
-       if (_session_range_location) {
-               _session_range_location->set_end (end);
+       string search_path;
+       vector<string> dirs;
+
+       if (path == ".") {
+               return;
+       }
+
+       switch (type) {
+       case DataType::AUDIO:
+               search_path = config.get_audio_search_path ();
+               break;
+       case DataType::MIDI:
+               search_path = config.get_midi_search_path ();
+               break;
+       }
+
+       split (search_path, dirs, ':');
+
+       for (vector<string>::iterator i = dirs.begin(); i != dirs.end(); ++i) {
+               if (*i == path) {
+                       return;
+               }
+       }
+
+       if (!search_path.empty()) {
+               search_path += ':';
+       }
+
+       search_path += path;
+        
+       switch (type) {
+       case DataType::AUDIO:
+               config.set_audio_search_path (search_path);
+               break;
+       case DataType::MIDI:
+               config.set_midi_search_path (search_path);
+               break;
+       }
+}
+
+boost::shared_ptr<Speakers>
+Session::get_speakers() 
+{
+       return _speakers;
+}
+
+list<string>
+Session::unknown_processors () const
+{
+       list<string> p;
+
+       boost::shared_ptr<RouteList> r = routes.reader ();
+       for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
+               list<string> t = (*i)->unknown_processors ();
+               copy (t.begin(), t.end(), back_inserter (p));
+       }
+
+       p.sort ();
+       p.unique ();
+
+       return p;
+}
+
+void
+Session::update_latency (bool playback)
+{
+       DEBUG_TRACE (DEBUG::Latency, string_compose ("JACK latency callback: %1\n", (playback ? "PLAYBACK" : "CAPTURE")));
+
+       if (_state_of_the_state & (InitialConnecting|Deletion)) {
+               return;
+       }
+
+       boost::shared_ptr<RouteList> r = routes.reader ();
+       framecnt_t max_latency = 0;
+
+       if (playback) {
+               /* reverse the list so that we work backwards from the last route to run to the first */
+               reverse (r->begin(), r->end());
+       }
+
+       /* compute actual latency values for the given direction and store them all in per-port
+          structures. this will also publish the same values (to JACK) so that computation of latency
+          for routes can consistently use public latency values.
+       */
+
+       for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
+               max_latency = max (max_latency, (*i)->set_private_port_latencies (playback));
+       }
+
+        /* because we latency compensate playback, our published playback latencies should
+           be the same for all output ports - all material played back by ardour has
+           the same latency, whether its caused by plugins or by latency compensation. since
+           these may differ from the values computed above, reset all playback port latencies
+           to the same value.
+        */
+
+        DEBUG_TRACE (DEBUG::Latency, string_compose ("Set public port latencies to %1\n", max_latency));
+        
+        for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
+                (*i)->set_public_port_latencies (max_latency, playback);
+        }
+                
+       if (playback) {
+
+               post_playback_latency ();
        } else {
-               add_session_range_location (end, end);
+
+               post_capture_latency ();
        }
+
+       DEBUG_TRACE (DEBUG::Latency, "JACK latency callback: DONE\n");
 }
 
-nframes_t
-Session::current_start_frame () const
+void
+Session::post_playback_latency ()
 {
-       return _session_range_location ? _session_range_location->start() : 0;
+       set_worst_playback_latency ();
+
+       boost::shared_ptr<RouteList> r = routes.reader (); 
+       for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
+               if (!(*i)->is_hidden() && ((*i)->active())) {
+                       _worst_track_latency = max (_worst_track_latency, (*i)->update_signal_latency ());
+               }
+                
+               for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
+                       (*i)->set_latency_compensation (_worst_track_latency);
+               }
+       }
 }
 
-nframes_t
-Session::current_end_frame () const
+void
+Session::post_capture_latency ()
 {
-       return _session_range_location ? _session_range_location->end() : 0;
+       set_worst_capture_latency ();
+        
+       /* reflect any changes in capture latencies into capture offsets
+        */
+        
+       boost::shared_ptr<RouteList> rl = routes.reader();
+       for (RouteList::iterator i = rl->begin(); i != rl->end(); ++i) {
+               boost::shared_ptr<Track> tr = boost::dynamic_pointer_cast<Track> (*i);
+               if (tr) {
+                       tr->set_capture_offset ();
+               }
+       }
+}
+
+void
+Session::set_worst_io_latencies ()
+{
+       set_worst_playback_latency ();
+       set_worst_capture_latency ();
+}
+
+void
+Session::set_worst_playback_latency ()
+{
+       if (_state_of_the_state & (InitialConnecting|Deletion)) {
+               return;
+       }
+
+       _worst_output_latency = 0;
+
+       if (!_engine.connected()) {
+               return;
+       }
+
+       boost::shared_ptr<RouteList> r = routes.reader ();
+
+       for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
+               _worst_output_latency = max (_worst_output_latency, (*i)->output()->latency());
+       }
+
+       DEBUG_TRACE (DEBUG::Latency, string_compose ("Worst output latency: %1\n", _worst_output_latency));
+}
+
+void
+Session::set_worst_capture_latency ()
+{
+       if (_state_of_the_state & (InitialConnecting|Deletion)) {
+               return;
+       }
+
+       _worst_input_latency = 0;
+
+       if (!_engine.connected()) {
+               return;
+       }
+
+       boost::shared_ptr<RouteList> r = routes.reader ();
+
+       for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
+               _worst_input_latency = max (_worst_input_latency, (*i)->input()->latency());
+       }
+
+        DEBUG_TRACE (DEBUG::Latency, string_compose ("Worst input latency: %1\n", _worst_input_latency));
 }
 
 void
-Session::add_session_range_location (nframes_t start, nframes_t end)
+Session::update_latency_compensation (bool force_whole_graph)
 {
-       _session_range_location = new Location (start, end, _("session"), Location::IsSessionRange);
-       _locations.add (_session_range_location);
+       bool some_track_latency_changed = false;
+
+       if (_state_of_the_state & (InitialConnecting|Deletion)) {
+               return;
+       }
+
+       DEBUG_TRACE(DEBUG::Latency, "---------------------------- update latency compensation\n\n");
+
+       _worst_track_latency = 0;
+
+       boost::shared_ptr<RouteList> r = routes.reader ();
+        
+       for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
+               if (!(*i)->is_hidden() && ((*i)->active())) {
+                       framecnt_t tl;
+                       if ((*i)->signal_latency () != (tl = (*i)->update_signal_latency ())) {
+                               some_track_latency_changed = true;
+                       }
+                       _worst_track_latency = max (tl, _worst_track_latency); 
+               }
+       }
+
+       DEBUG_TRACE (DEBUG::Latency, string_compose ("worst signal processing latency: %1 (changed ? %2)\n", _worst_track_latency,
+                                                    (some_track_latency_changed ? "yes" : "no")));
+
+       if (force_whole_graph || some_track_latency_changed) {
+               /* trigger a full recompute of latency numbers for the graph.
+                  everything else that we need to do will be done in the latency
+                  callback.
+               */
+               _engine.update_total_latencies ();
+               return; // everything else will be done in the latency callback
+       } 
+
+       DEBUG_TRACE(DEBUG::Latency, "---------------------------- DONE update latency compensation\n\n")
 }
+