Use a shared_ptr for SessionPlaylists so that it can be explicitly destroyed in ...
[ardour.git] / libs / ardour / session.cc
index b9144aa3b6a083ea3a4d35267c47cc2ad9d5ee32..9cb4cc32849506a0fd00e14bd0c2afc1ad76e658 100644 (file)
 #include <glibmm/miscutils.h>
 #include <glibmm/fileutils.h>
 
-#include <pbd/error.h>
+#include "pbd/error.h"
 #include <glibmm/thread.h>
-#include <pbd/pathscanner.h>
-#include <pbd/stl_delete.h>
-#include <pbd/basename.h>
-#include <pbd/stacktrace.h>
-#include <pbd/file_utils.h>
-
-#include <ardour/analyser.h>
-#include <ardour/audio_buffer.h>
-#include <ardour/audio_diskstream.h>
-#include <ardour/audio_track.h>
-#include <ardour/audioengine.h>
-#include <ardour/audiofilesource.h>
-#include <ardour/audioplaylist.h>
-#include <ardour/audioregion.h>
-#include <ardour/auditioner.h>
-#include <ardour/buffer_set.h>
-#include <ardour/bundle.h>
-#include <ardour/click.h>
-#include <ardour/configuration.h>
-#include <ardour/crossfade.h>
-#include <ardour/cycle_timer.h>
-#include <ardour/data_type.h>
-#include <ardour/filename_extensions.h>
-#include <ardour/io_processor.h>
-#include <ardour/midi_diskstream.h>
-#include <ardour/midi_playlist.h>
-#include <ardour/midi_region.h>
-#include <ardour/midi_track.h>
-#include <ardour/named_selection.h>
-#include <ardour/playlist.h>
-#include <ardour/plugin_insert.h>
-#include <ardour/port_insert.h>
-#include <ardour/processor.h>
-#include <ardour/recent_sessions.h>
-#include <ardour/region_factory.h>
-#include <ardour/route_group.h>
-#include <ardour/send.h>
-#include <ardour/session.h>
-#include <ardour/session_directory.h>
-#include <ardour/session_directory.h>
-#include <ardour/session_metadata.h>
-#include <ardour/slave.h>
-#include <ardour/smf_source.h>
-#include <ardour/source_factory.h>
-#include <ardour/tape_file_matcher.h>
-#include <ardour/tempo.h>
-#include <ardour/utils.h>
+#include "pbd/boost_debug.h"
+#include "pbd/pathscanner.h"
+#include "pbd/stl_delete.h"
+#include "pbd/basename.h"
+#include "pbd/stacktrace.h"
+#include "pbd/file_utils.h"
+
+#include "ardour/amp.h"
+#include "ardour/analyser.h"
+#include "ardour/audio_buffer.h"
+#include "ardour/audio_diskstream.h"
+#include "ardour/audio_port.h"
+#include "ardour/audio_track.h"
+#include "ardour/audioengine.h"
+#include "ardour/audiofilesource.h"
+#include "ardour/audioplaylist.h"
+#include "ardour/audioregion.h"
+#include "ardour/auditioner.h"
+#include "ardour/buffer_set.h"
+#include "ardour/bundle.h"
+#include "ardour/butler.h"
+#include "ardour/click.h"
+#include "ardour/configuration.h"
+#include "ardour/crossfade.h"
+#include "ardour/cycle_timer.h"
+#include "ardour/data_type.h"
+#include "ardour/debug.h"
+#include "ardour/filename_extensions.h"
+#include "ardour/internal_send.h"
+#include "ardour/io_processor.h"
+#include "ardour/midi_diskstream.h"
+#include "ardour/midi_playlist.h"
+#include "ardour/midi_region.h"
+#include "ardour/midi_track.h"
+#include "ardour/named_selection.h"
+#include "ardour/playlist.h"
+#include "ardour/plugin_insert.h"
+#include "ardour/port_insert.h"
+#include "ardour/processor.h"
+#include "ardour/rc_configuration.h"
+#include "ardour/recent_sessions.h"
+#include "ardour/region_factory.h"
+#include "ardour/return.h"
+#include "ardour/route_group.h"
+#include "ardour/send.h"
+#include "ardour/session.h"
+#include "ardour/session_directory.h"
+#include "ardour/session_directory.h"
+#include "ardour/session_metadata.h"
+#include "ardour/session_playlists.h"
+#include "ardour/slave.h"
+#include "ardour/smf_source.h"
+#include "ardour/source_factory.h"
+#include "ardour/tape_file_matcher.h"
+#include "ardour/tempo.h"
+#include "ardour/utils.h"
 
 #include "i18n.h"
 
@@ -91,12 +100,7 @@ using namespace std;
 using namespace ARDOUR;
 using namespace PBD;
 using boost::shared_ptr;
-
-#ifdef __x86_64__
-static const int CPU_CACHE_ALIGN = 64;
-#else
-static const int CPU_CACHE_ALIGN = 16; /* arguably 32 on most arches, but it matters less */
-#endif
+using boost::weak_ptr;
 
 bool Session::_disable_all_loaded_plugins = false;
 
@@ -105,7 +109,7 @@ sigc::signal<int> Session::AskAboutPendingState;
 sigc::signal<int,nframes_t,nframes_t> Session::AskAboutSampleRateMismatch;
 sigc::signal<void> Session::SendFeedback;
 
-sigc::signal<void> Session::SMPTEOffsetChanged;
+sigc::signal<void> Session::TimecodeOffsetChanged;
 sigc::signal<void> Session::StartTimeChanged;
 sigc::signal<void> Session::EndTimeChanged;
 sigc::signal<void> Session::AutoBindingOn;
@@ -118,6 +122,7 @@ Session::Session (AudioEngine &eng,
                  string mix_template)
 
        : _engine (eng),
+         _target_transport_speed (0.0),
          _requested_return_frame (-1),
          _scratch_buffers(new BufferSet()),
          _silent_buffers(new BufferSet()),
@@ -128,17 +133,14 @@ Session::Session (AudioEngine &eng,
          _midi_port (default_midi_port),
          _midi_clock_port (default_midi_clock_port),
          _session_dir (new SessionDirectory(fullpath)),
-         pending_events (2048),
          state_tree (0),
-         butler_mixdown_buffer (0),
-         butler_gain_buffer (0),
-         post_transport_work((PostTransportWork)0),
-         _send_smpte_update (false),
+         _butler (new Butler (this)),
+         _post_transport_work (0),
+         _send_timecode_update (false),
          midi_thread (pthread_t (0)),
          midi_requests (128), // the size of this should match the midi request pool size
          diskstreams (new DiskstreamList),
          routes (new RouteList),
-         auditioner ((Auditioner*) 0),
          _total_free_4k_blocks (0),
          _bundles (new BundleList),
          _bundle_xml_node (0),
@@ -146,16 +148,21 @@ Session::Session (AudioEngine &eng,
          click_data (0),
          click_emphasis_data (0),
          main_outs (0),
-         _metadata (new SessionMetadata())
+         _metadata (new SessionMetadata()),
+         _have_rec_enabled_diskstream (false)
 
 {
+       playlists.reset (new SessionPlaylists);
+       
        bool new_session;
 
+       interpolation.add_channel_to (0, 0);
+
        if (!eng.connected()) {
                throw failed_constructor();
        }
 
-       cerr << "Loading session " << fullpath << " using snapshot " << snapshot_name << " (1)" << endl;
+       info << "Loading session " << fullpath << " using snapshot " << snapshot_name << " (1)" << endl;
 
        n_physical_outputs = _engine.n_physical_outputs(DataType::AUDIO);
        n_physical_inputs =  _engine.n_physical_inputs(DataType::AUDIO);
@@ -182,7 +189,8 @@ Session::Session (AudioEngine &eng,
 
        _state_of_the_state = StateOfTheState (_state_of_the_state & ~Dirty);
 
-       Config->ParameterChanged.connect (mem_fun (*this, &Session::config_changed));
+       Config->ParameterChanged.connect (bind (mem_fun (*this, &Session::config_changed), false));
+       config.ParameterChanged.connect (bind (mem_fun (*this, &Session::config_changed), true));
 
        if (was_dirty) {
                DirtyChanged (); /* EMIT SIGNAL */
@@ -201,6 +209,7 @@ Session::Session (AudioEngine &eng,
                  nframes_t initial_length)
 
        : _engine (eng),
+         _target_transport_speed (0.0),
          _requested_return_frame (-1),
          _scratch_buffers(new BufferSet()),
          _silent_buffers(new BufferSet()),
@@ -211,17 +220,14 @@ Session::Session (AudioEngine &eng,
          _midi_port (default_midi_port),
          _midi_clock_port (default_midi_clock_port),
          _session_dir ( new SessionDirectory(fullpath)),
-         pending_events (2048),
          state_tree (0),
-         butler_mixdown_buffer (0),
-         butler_gain_buffer (0),
-         post_transport_work((PostTransportWork)0),
-         _send_smpte_update (false),
+         _butler (new Butler (this)),
+         _post_transport_work (0),
+         _send_timecode_update (false),
          midi_thread (pthread_t (0)),
          midi_requests (16),
          diskstreams (new DiskstreamList),
          routes (new RouteList),
-         auditioner ((Auditioner *) 0),
          _total_free_4k_blocks (0),
          _bundles (new BundleList),
          _bundle_xml_node (0),
@@ -229,15 +235,20 @@ Session::Session (AudioEngine &eng,
          click_data (0),
          click_emphasis_data (0),
          main_outs (0),
-         _metadata (new SessionMetadata())
+         _metadata (new SessionMetadata()),
+         _have_rec_enabled_diskstream (false)
 {
+       playlists.reset (new SessionPlaylists);
+
        bool new_session;
 
+       interpolation.add_channel_to (0, 0);
+
        if (!eng.connected()) {
                throw failed_constructor();
        }
 
-       cerr << "Loading session " << fullpath << " using snapshot " << snapshot_name << " (2)" << endl;
+       info << "Loading session " << fullpath << " using snapshot " << snapshot_name << " (2)" << endl;
 
        n_physical_outputs = _engine.n_physical_outputs (DataType::AUDIO);
        n_physical_inputs = _engine.n_physical_inputs (DataType::AUDIO);
@@ -267,15 +278,11 @@ Session::Session (AudioEngine &eng,
                RouteList rl;
                int control_id = 1;
 
-               if (control_out_channels) {
-                       shared_ptr<Route> r (new Route (*this, _("monitor"), -1, control_out_channels, -1, control_out_channels, Route::ControlOut));
-                       r->set_remote_control_id (control_id++);
-
-                       rl.push_back (r);
-               }
-
                if (master_out_channels) {
-                       shared_ptr<Route> r (new Route (*this, _("master"), -1, master_out_channels, -1, master_out_channels, Route::MasterOut));
+                       ChanCount count(DataType::AUDIO, master_out_channels);
+                       shared_ptr<Route> r (new Route (*this, _("master"), Route::MasterOut, DataType::AUDIO));
+                       r->input()->ensure_io (count, false, this);
+                       r->output()->ensure_io (count, false, this);
                        r->set_remote_control_id (control_id);
 
                        rl.push_back (r);
@@ -284,12 +291,27 @@ Session::Session (AudioEngine &eng,
                        output_ac = AutoConnectOption (output_ac & ~AutoConnectMaster);
                }
 
+               if (control_out_channels) {
+                       ChanCount count(DataType::AUDIO, control_out_channels);
+                       shared_ptr<Route> r (new Route (*this, _("monitor"), Route::ControlOut, DataType::AUDIO));
+                       r->input()->ensure_io (count, false, this);
+                       r->output()->ensure_io (count, false, this);
+                       r->set_remote_control_id (control_id++);
+
+                       rl.push_back (r);
+               }
+
                if (!rl.empty()) {
                        add_routes (rl, false);
                }
 
        }
 
+       if (no_auto_connect()) {
+               input_ac = AutoConnectOption (0);
+               output_ac = AutoConnectOption (0);
+       }
+
        Config->set_input_auto_connect (input_ac);
        Config->set_output_auto_connect (output_ac);
 
@@ -302,7 +324,7 @@ Session::Session (AudioEngine &eng,
 
        _state_of_the_state = StateOfTheState (_state_of_the_state & ~Dirty);
 
-       Config->ParameterChanged.connect (mem_fun (*this, &Session::config_changed));
+       Config->ParameterChanged.connect (bind (mem_fun (*this, &Session::config_changed), false));
 }
 
 Session::~Session ()
@@ -313,6 +335,8 @@ Session::~Session ()
 void
 Session::destroy ()
 {
+       vector<void*> debug_pointers;
+
        /* if we got to here, leaving pending capture state around
           is a mistake.
        */
@@ -337,7 +361,11 @@ Session::destroy ()
 
        delete state_tree;
 
-       terminate_butler_thread ();
+       /* reset dynamic state version back to default */
+
+       Stateful::loading_state_version = 0;
+
+       _butler->terminate_thread ();
        //terminate_midi_thread ();
 
        if (click_data != default_click) {
@@ -354,14 +382,17 @@ Session::destroy ()
        delete _silent_buffers;
        delete _mix_buffers;
 
+       /* clear out any pending dead wood from RCU managed objects */
+
+       routes.flush ();
+       diskstreams.flush ();
+       _bundles.flush ();
+       
        AudioDiskstream::free_working_buffers();
 
        Route::SyncOrderKeys.clear();
 
-#undef TRACK_DESTRUCTION
-#ifdef TRACK_DESTRUCTION
-       cerr << "delete named selections\n";
-#endif /* TRACK_DESTRUCTION */
+       DEBUG_TRACE (DEBUG::Destruction, "delete named selections\n");
        for (NamedSelectionList::iterator i = named_selections.begin(); i != named_selections.end(); ) {
                NamedSelectionList::iterator tmp;
 
@@ -372,128 +403,84 @@ Session::destroy ()
                i = tmp;
        }
 
-#ifdef TRACK_DESTRUCTION
-       cerr << "delete playlists\n";
-#endif /* TRACK_DESTRUCTION */
-       for (PlaylistList::iterator i = playlists.begin(); i != playlists.end(); ) {
-               PlaylistList::iterator tmp;
-
-               tmp = i;
-               ++tmp;
-
-               (*i)->drop_references ();
-
-               i = tmp;
-       }
-
-       for (PlaylistList::iterator i = unused_playlists.begin(); i != unused_playlists.end(); ) {
-               PlaylistList::iterator tmp;
-
-               tmp = i;
-               ++tmp;
-
-               (*i)->drop_references ();
-
-               i = tmp;
-       }
-
-       playlists.clear ();
-       unused_playlists.clear ();
-
-#ifdef TRACK_DESTRUCTION
-       cerr << "delete regions\n";
-#endif /* TRACK_DESTRUCTION */
-
+       DEBUG_TRACE (DEBUG::Destruction, "delete regions\n");
        for (RegionList::iterator i = regions.begin(); i != regions.end(); ) {
                RegionList::iterator tmp;
 
                tmp = i;
                ++tmp;
-
+               
+               DEBUG_TRACE(DEBUG::Destruction, string_compose ("Dropping for region %1 (%2); pre-ref = %2\n", i->second->name(), i->second.get(), i->second.use_count()));
                i->second->drop_references ();
-
+               DEBUG_TRACE(DEBUG::Destruction, string_compose ("region post ref = %1\n", i->second.use_count()));
                i = tmp;
        }
 
        regions.clear ();
 
-#ifdef TRACK_DESTRUCTION
-       cerr << "delete routes\n";
-#endif /* TRACK_DESTRUCTION */
+       DEBUG_TRACE (DEBUG::Destruction, "delete routes\n");
+       
+       /* reset these three references to special routes before we do the usual route delete thing */
+
+       auditioner.reset ();
+       _master_out.reset ();
+       _control_out.reset ();
+
        {
                RCUWriter<RouteList> writer (routes);
                boost::shared_ptr<RouteList> r = writer.get_copy ();
                for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
+                       DEBUG_TRACE(DEBUG::Destruction, string_compose ("Dropping for route %1 ; pre-ref = %2\n", (*i)->name(), (*i).use_count()));
                        (*i)->drop_references ();
                }
                r->clear ();
                /* writer goes out of scope and updates master */
        }
-
        routes.flush ();
 
-#ifdef TRACK_DESTRUCTION
-       cerr << "delete diskstreams\n";
-#endif /* TRACK_DESTRUCTION */
-       {
-              RCUWriter<DiskstreamList> dwriter (diskstreams);
-              boost::shared_ptr<DiskstreamList> dsl = dwriter.get_copy();
-              for (DiskstreamList::iterator i = dsl->begin(); i != dsl->end(); ++i) {
-                      (*i)->drop_references ();
-              }
-              dsl->clear ();
-       }
-       diskstreams.flush ();
-
-#ifdef TRACK_DESTRUCTION
-       cerr << "delete audio sources\n";
-#endif /* TRACK_DESTRUCTION */
+       DEBUG_TRACE (DEBUG::Destruction, "delete diskstreams\n");
+       {
+               RCUWriter<DiskstreamList> dwriter (diskstreams);
+               boost::shared_ptr<DiskstreamList> dsl = dwriter.get_copy();
+               for (DiskstreamList::iterator i = dsl->begin(); i != dsl->end(); ++i) {
+                       DEBUG_TRACE(DEBUG::Destruction, string_compose ("Dropping for diskstream %1 ; pre-ref = %2\n", (*i)->name(), (*i).use_count()));
+                       (*i)->drop_references ();
+               }
+               dsl->clear ();
+       }
+       diskstreams.flush ();
+
+       DEBUG_TRACE (DEBUG::Destruction, "delete sources\n");
        for (SourceMap::iterator i = sources.begin(); i != sources.end(); ) {
                SourceMap::iterator tmp;
 
                tmp = i;
                ++tmp;
 
+               DEBUG_TRACE(DEBUG::Destruction, string_compose ("Dropping for source %1 ; pre-ref = %2\n", i->second->path(), i->second.use_count()));
                i->second->drop_references ();
 
                i = tmp;
        }
+
        sources.clear ();
 
-#ifdef TRACK_DESTRUCTION
-       cerr << "delete mix groups\n";
-#endif /* TRACK_DESTRUCTION */
-       for (list<RouteGroup *>::iterator i = mix_groups.begin(); i != mix_groups.end(); ) {
-               list<RouteGroup*>::iterator tmp;
-
-               tmp = i;
-               ++tmp;
 
+       DEBUG_TRACE (DEBUG::Destruction, "delete route groups\n");
+       for (list<RouteGroup *>::iterator i = _route_groups.begin(); i != _route_groups.end(); ++i) {
                delete *i;
-
-               i = tmp;
        }
 
-#ifdef TRACK_DESTRUCTION
-       cerr << "delete edit groups\n";
-#endif /* TRACK_DESTRUCTION */
-       for (list<RouteGroup *>::iterator i = edit_groups.begin(); i != edit_groups.end(); ) {
-               list<RouteGroup*>::iterator tmp;
-
-               tmp = i;
-               ++tmp;
-
-               delete *i;
+       Crossfade::set_buffer_size (0);
 
-               i = tmp;
-       }
+       delete mmc;
 
-       delete [] butler_mixdown_buffer;
-       delete [] butler_gain_buffer;
+       /* not strictly necessary, but doing it here allows the shared_ptr debugging to work */
+       playlists.reset ();
 
-       Crossfade::set_buffer_size (0);
+       boost_debug_list_ptrs ();
 
-       delete mmc;
+       DEBUG_TRACE (DEBUG::Destruction, "Session::destroy() done\n");
 }
 
 void
@@ -509,8 +496,8 @@ Session::set_worst_io_latencies ()
        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());
+               _worst_output_latency = max (_worst_output_latency, (*i)->output()->latency());
+               _worst_input_latency = max (_worst_input_latency, (*i)->input()->latency());
        }
 }
 
@@ -519,8 +506,6 @@ Session::when_engine_running ()
 {
        string first_physical_output;
 
-       /* we don't want to run execute this again */
-
        BootMessage (_("Set block size and sample rate"));
 
        set_block_size (_engine.frames_per_cycle());
@@ -528,7 +513,8 @@ Session::when_engine_running ()
 
        BootMessage (_("Using configuration"));
 
-       Config->map_parameters (mem_fun (*this, &Session::config_changed));
+       Config->map_parameters (bind (mem_fun (*this, &Session::config_changed), false));
+       config.map_parameters (bind (mem_fun (*this, &Session::config_changed), true));
 
        /* every time we reconnect, recompute worst case output latencies */
 
@@ -538,7 +524,7 @@ Session::when_engine_running ()
                _engine.transport_stop ();
        }
 
-       if (Config->get_jack_time_master()) {
+       if (config.get_jack_time_master()) {
                _engine.transport_locate (_transport_frame);
        }
 
@@ -547,35 +533,47 @@ Session::when_engine_running ()
        try {
                XMLNode* child = 0;
 
-               _click_io.reset (new ClickIO (*this, "click", 0, 0, -1, -1));
+               _click_io.reset (new ClickIO (*this, "click"));
 
                if (state_tree && (child = find_named_node (*state_tree->root(), "Click")) != 0) {
 
                        /* existing state for Click */
+                       int c;
 
-                       if (_click_io->set_state (*child->children().front()) == 0) {
+                       if (Stateful::loading_state_version < 3000) {
+                               c = _click_io->set_state_2X (*child->children().front(), Stateful::loading_state_version, false);
+                       } else {
+                               c = _click_io->set_state (*child->children().front(), Stateful::loading_state_version);
+                       }
+                                       
 
+                       if (c == 0) {
                                _clicking = Config->get_clicking ();
-
+                               
                        } else {
-
+                               
                                error << _("could not setup Click I/O") << endmsg;
                                _clicking = false;
                        }
 
+
                } else {
 
-                       /* default state for Click */
+                       /* default state for Click: dual-mono to first 2 physical outputs */
 
-                       first_physical_output = _engine.get_nth_physical_output (DataType::AUDIO, 0);
+                       for (int physport = 0; physport < 2; ++physport) {
+                               string physical_output = _engine.get_nth_physical_output (DataType::AUDIO, physport);
 
-                       if (first_physical_output.length()) {
-                               if (_click_io->add_output_port (first_physical_output, this)) {
-                                       // relax, even though its an error
-                               } else {
-                                       _clicking = Config->get_clicking ();
-                               }
-                       }
+                               if (physical_output.length()) {
+                                       if (_click_io->add_port (physical_output, this)) {
+                                               // relax, even though its an error
+                                      }
+                              }
+                      }
+
+                       if (_click_io->n_ports () > ChanCount::ZERO) {
+                               _clicking = Config->get_clicking ();
+                       }
                }
        }
 
@@ -598,19 +596,24 @@ Session::when_engine_running ()
           mono and stereo bundles, so that the common cases of mono
           and stereo tracks get bundles to put in their mixer strip
           in / out menus.  There may be a nicer way of achieving that;
-          it doesn't really scale that well to higher channel counts */
+          it doesn't really scale that well to higher channel counts
+       */
+
+       /* mono output bundles */
 
        for (uint32_t np = 0; np < n_physical_outputs; ++np) {
                char buf[32];
                snprintf (buf, sizeof (buf), _("out %" PRIu32), np+1);
 
-               shared_ptr<Bundle> c (new Bundle (buf, true));
+               shared_ptr<Bundle> c (new Bundle (buf, true));
                c->add_channel (_("mono"));
-               c->set_port (0, _engine.get_nth_physical_output (DataType::AUDIO, np));
+               c->set_port (0, _engine.get_nth_physical_output (DataType::AUDIO, np));
 
-               add_bundle (c);
+               add_bundle (c);
        }
 
+       /* stereo output bundles */
+
        for (uint32_t np = 0; np < n_physical_outputs; np += 2) {
                if (np + 1 < n_physical_outputs) {
                        char buf[32];
@@ -625,17 +628,21 @@ Session::when_engine_running ()
                }
        }
 
+       /* mono input bundles */
+
        for (uint32_t np = 0; np < n_physical_inputs; ++np) {
                char buf[32];
                snprintf (buf, sizeof (buf), _("in %" PRIu32), np+1);
 
-               shared_ptr<Bundle> c (new Bundle (buf, false));
+               shared_ptr<Bundle> c (new Bundle (buf, false));
                c->add_channel (_("mono"));
-               c->set_port (0, _engine.get_nth_physical_input (DataType::AUDIO, np));
+               c->set_port (0, _engine.get_nth_physical_input (DataType::AUDIO, np));
 
-               add_bundle (c);
+               add_bundle (c);
        }
 
+       /* stereo input bundles */
+
        for (uint32_t np = 0; np < n_physical_inputs; np += 2) {
                if (np + 1 < n_physical_inputs) {
                        char buf[32];
@@ -651,79 +658,108 @@ Session::when_engine_running ()
                }
        }
 
-       if (_master_out) {
+       BootMessage (_("Setup signal flow and plugins"));
 
-               /* create master/control ports */
+       hookup_io ();
 
-               if (_master_out) {
-                       uint32_t n;
+       if (!no_auto_connect()) {
 
-                       /* force the master to ignore any later call to this */
+               if (_master_out && Config->get_auto_connect_standard_busses()) {
 
-                       if (_master_out->pending_state_node) {
-                               _master_out->ports_became_legal();
-                       }
+                       /* if requested auto-connect the outputs to the first N physical ports.
+                        */
 
-                       /* no panner resets till we are through */
+                       uint32_t limit = _master_out->n_outputs().n_total();
 
-                       _master_out->defer_pan_reset ();
+                       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);
 
-                       while (_master_out->n_inputs().n_audio()
-                                       < _master_out->input_maximum().n_audio()) {
-                               if (_master_out->add_input_port ("", this, DataType::AUDIO)) {
-                                       error << _("cannot setup master inputs")
-                                             << endmsg;
-                                       break;
+                               if (!connect_to.empty() && p->connected_to (connect_to) == false) {
+                                       if (_master_out->output()->connect (p, connect_to, this)) {
+                                               error << string_compose (_("cannot connect master output %1 to %2"), n, connect_to)
+                                                     << endmsg;
+                                               break;
+                                       }
                                }
                        }
-                       n = 0;
-                       while (_master_out->n_outputs().n_audio()
-                                       < _master_out->output_maximum().n_audio()) {
-                               if (_master_out->add_output_port (_engine.get_nth_physical_output (DataType::AUDIO, n), this, DataType::AUDIO)) {
-                                       error << _("cannot setup master outputs")
-                                             << endmsg;
-                                       break;
+               }
+
+               if (_control_out) {
+
+                       /* AUDIO ONLY as of june 29th 2009, because listen semantics for anything else
+                          are undefined, at best.
+                        */
+
+                       /* control out listens to master bus (but ignores it
+                          under some conditions)
+                       */
+
+                       uint32_t limit = _control_out->n_inputs().n_audio();
+
+                       if (_master_out) {
+                               for (uint32_t n = 0; n < limit; ++n) {
+                                       AudioPort* p = _control_out->input()->ports().nth_audio_port (n);
+                                       AudioPort* o = _master_out->output()->ports().nth_audio_port (n);
+
+                                       if (o) {
+                                               string connect_to = o->name();
+                                               if (_control_out->input()->connect (p, connect_to, this)) {
+                                                       error << string_compose (_("cannot connect control input %1 to %2"), n, connect_to)
+                                                             << endmsg;
+                                                       break;
+                                               }
+                                       }
                                }
-                               n++;
                        }
 
-                       _master_out->allow_pan_reset ();
+                       /* if control out is not connected,
+                          connect control out to physical outs, but use ones after the master if possible
+                       */
 
-               }
-       }
+                       if (!_control_out->output()->connected_to (boost::shared_ptr<IO>())) {
 
-       BootMessage (_("Setup signal flow and plugins"));
+                               if (!Config->get_monitor_bus_preferred_bundle().empty()) {
 
-       hookup_io ();
+                                       boost::shared_ptr<Bundle> b = bundle_by_name (Config->get_monitor_bus_preferred_bundle());
 
-       /* catch up on send+insert cnts */
+                                       if (b) {
+                                               _control_out->output()->connect_ports_to_bundle (b, this);
+                                       } else {
+                                               warning << string_compose (_("The preferred I/O for the monitor bus (%1) cannot be found"),
+                                                                          Config->get_monitor_bus_preferred_bundle())
+                                                       << endmsg;
+                                       }
 
-       BootMessage (_("Catch up with send/insert state"));
+                               } else {
 
-       insert_cnt = 0;
+                                       /* XXX this logic is wrong for mixed port types */
 
-       for (list<PortInsert*>::iterator i = _port_inserts.begin(); i != _port_inserts.end(); ++i) {
-               uint32_t id;
+                                       uint32_t shift = _master_out->n_outputs().n_audio();
+                                       uint32_t mod = _engine.n_physical_outputs (DataType::AUDIO);
+                                       limit = _control_out->n_outputs().n_audio();
 
-               if (sscanf ((*i)->name().c_str(), "%*s %u", &id) == 1) {
-                       if (id > insert_cnt) {
-                               insert_cnt = id;
-                       }
-               }
-       }
+                                       cerr << "Connecting " << limit << " control out ports, shift is " << shift << " mod is " << mod << endl;
 
-       send_cnt = 0;
+                                       for (uint32_t n = 0; n < limit; ++n) {
 
-       for (list<Send*>::iterator i = _sends.begin(); i != _sends.end(); ++i) {
-               uint32_t id;
+                                               Port* p = _control_out->output()->nth (n);
+                                               string connect_to = _engine.get_nth_physical_output (DataType (p->type()), (n+shift) % mod);
 
-               if (sscanf ((*i)->name().c_str(), "%*s %u", &id) == 1) {
-                       if (id > send_cnt) {
-                               send_cnt = id;
+                                               if (!connect_to.empty()) {
+                                                       if (_control_out->output()->connect (p, connect_to, this)) {
+                                                               error << string_compose (_("cannot connect control output %1 to %2"), n, connect_to)
+                                                                     << endmsg;
+                                                               break;
+                                                       }
+                                               }
+                                       }
+                               }
                        }
                }
        }
 
+       /* catch up on send+insert cnts */
 
        _state_of_the_state = StateOfTheState (_state_of_the_state & ~(CannotSave|Dirty));
 
@@ -744,7 +780,7 @@ Session::hookup_io ()
        _state_of_the_state = StateOfTheState (_state_of_the_state | InitialConnecting);
 
 
-       if (auditioner == 0) {
+       if (!auditioner) {
 
                /* we delay creating the auditioner till now because
                   it makes its own connections to ports.
@@ -760,45 +796,6 @@ Session::hookup_io ()
                }
        }
 
-       /* Tell all IO objects to create their ports */
-
-       IO::enable_ports ();
-
-       if (_control_out) {
-               uint32_t n;
-               vector<string> cports;
-
-               while (_control_out->n_inputs().n_audio() < _control_out->input_maximum().n_audio()) {
-                       if (_control_out->add_input_port ("", this)) {
-                               error << _("cannot setup control inputs")
-                                     << endmsg;
-                               break;
-                       }
-               }
-               n = 0;
-               while (_control_out->n_outputs().n_audio() < _control_out->output_maximum().n_audio()) {
-                       if (_control_out->add_output_port (_engine.get_nth_physical_output (DataType::AUDIO, n), this)) {
-                               error << _("cannot set up master outputs")
-                                     << endmsg;
-                               break;
-                       }
-                       n++;
-               }
-
-
-               uint32_t ni = _control_out->n_inputs().get (DataType::AUDIO);
-
-               for (n = 0; n < ni; ++n) {
-                       cports.push_back (_control_out->input(n)->name());
-               }
-
-               boost::shared_ptr<RouteList> r = routes.reader ();
-
-               for (RouteList::iterator x = r->begin(); x != r->end(); ++x) {
-                       (*x)->set_control_outs (cports);
-               }
-       }
-
        /* load bundles, which we may have postponed earlier on */
        if (_bundle_xml_node) {
                load_bundles (*_bundle_xml_node);
@@ -811,7 +808,25 @@ Session::hookup_io ()
 
        /* Now reset all panners */
 
-       IO::reset_panners ();
+       Delivery::reset_panners ();
+
+       /* Connect tracks to listen/solo etc. busses XXX generalize this beyond control_out */
+
+       if (_control_out) {
+
+               boost::shared_ptr<RouteList> r = routes.reader ();
+
+               for (RouteList::iterator x = r->begin(); x != r->end(); ++x) {
+
+                       if ((*x)->is_control() || (*x)->is_master()) {
+                               continue;
+                       }
+
+                       (*x)->listen_via (_control_out,
+                                         (Config->get_listen_position() == AfterFaderListen ? PostFader : PreFader),
+                                         false, false);
+               }
+       }
 
        /* Anyone who cares about input state, wake up and do something */
 
@@ -819,16 +834,19 @@ Session::hookup_io ()
 
        _state_of_the_state = StateOfTheState (_state_of_the_state & ~InitialConnecting);
 
-
        /* now handle the whole enchilada as if it was one
           graph reorder event.
        */
 
        graph_reordered ();
 
-       /* update mixer solo state */
+       /* update the full solo state, which can't be
+          correctly determined on a per-route basis, but
+          needs the global overview that only the session
+          has.
+       */
 
-       catch_up_on_solo();
+       update_route_solo_state ();
 }
 
 void
@@ -844,8 +862,13 @@ Session::playlist_length_changed ()
 }
 
 void
-Session::diskstream_playlist_changed (boost::shared_ptr<Diskstream> dstream)
+Session::diskstream_playlist_changed (boost::weak_ptr<Diskstream> wp)
 {
+       boost::shared_ptr<Diskstream> dstream = wp.lock ();
+       if (!dstream) {
+               return;
+       }
+       
        boost::shared_ptr<Playlist> playlist;
 
        if ((playlist = dstream->playlist()) != 0) {
@@ -860,9 +883,9 @@ bool
 Session::record_enabling_legal () const
 {
        /* this used to be in here, but survey says.... we don't need to restrict it */
-       // if (record_status() == Recording) {
-       //      return false;
-       // }
+       // if (record_status() == Recording) {
+       //      return false;
+       // }
 
        if (Config->get_all_safe()) {
                return false;
@@ -880,7 +903,7 @@ Session::reset_input_monitor_state ()
                for (DiskstreamList::iterator i = dsl->begin(); i != dsl->end(); ++i) {
                        if ((*i)->record_enabled ()) {
                                //cerr << "switching to input = " << !auto_input << __FILE__ << __LINE__ << endl << endl;
-                               (*i)->monitor_input (Config->get_monitoring_model() == HardwareMonitoring && !Config->get_auto_input());
+                               (*i)->monitor_input (Config->get_monitoring_model() == HardwareMonitoring && !config.get_auto_input());
                        }
                }
        } else {
@@ -898,9 +921,9 @@ Session::reset_input_monitor_state ()
 void
 Session::auto_punch_start_changed (Location* location)
 {
-       replace_event (Event::PunchIn, location->start());
+       replace_event (SessionEvent::PunchIn, location->start());
 
-       if (get_record_enabled() && Config->get_punch_in()) {
+       if (get_record_enabled() && config.get_punch_in()) {
                /* capture start has been changed, so save new pending state */
                save_state ("", true);
        }
@@ -911,7 +934,7 @@ Session::auto_punch_end_changed (Location* location)
 {
        nframes_t when_to_stop = location->end();
        // when_to_stop += _worst_output_latency + _worst_input_latency;
-       replace_event (Event::PunchOut, when_to_stop);
+       replace_event (SessionEvent::PunchOut, when_to_stop);
 }
 
 void
@@ -919,23 +942,24 @@ Session::auto_punch_changed (Location* location)
 {
        nframes_t when_to_stop = location->end();
 
-       replace_event (Event::PunchIn, location->start());
+       replace_event (SessionEvent::PunchIn, location->start());
        //when_to_stop += _worst_output_latency + _worst_input_latency;
-       replace_event (Event::PunchOut, when_to_stop);
+       replace_event (SessionEvent::PunchOut, when_to_stop);
 }
 
 void
 Session::auto_loop_changed (Location* location)
 {
-       replace_event (Event::AutoLoop, location->end(), location->start());
+       replace_event (SessionEvent::AutoLoop, location->end(), location->start());
 
        if (transport_rolling() && play_loop) {
 
-               //if (_transport_frame < location->start() || _transport_frame > location->end()) {
 
-               if (_transport_frame > location->end()) {
+               // if (_transport_frame > location->end()) {
+
+               if (_transport_frame < location->start() || _transport_frame > location->end()) {
                        // relocate to beginning of loop
-                       clear_events (Event::LocateRoll);
+                       clear_events (SessionEvent::LocateRoll);
 
                        request_locate (location->start(), true);
 
@@ -947,8 +971,8 @@ Session::auto_loop_changed (Location* location)
                        loop_changing = true;
 
                        if (location->end() > last_loopend) {
-                               clear_events (Event::LocateRoll);
-                               Event *ev = new Event (Event::LocateRoll, Event::Add, last_loopend, last_loopend, 0, true);
+                               clear_events (SessionEvent::LocateRoll);
+                               SessionEvent *ev = new SessionEvent (SessionEvent::LocateRoll, SessionEvent::Add, last_loopend, last_loopend, 0, true);
                                queue_event (ev);
                        }
 
@@ -968,8 +992,8 @@ Session::set_auto_punch_location (Location* location)
                auto_punch_end_changed_connection.disconnect();
                auto_punch_changed_connection.disconnect();
                existing->set_auto_punch (false, this);
-               remove_event (existing->start(), Event::PunchIn);
-               clear_events (Event::PunchOut);
+               remove_event (existing->start(), SessionEvent::PunchIn);
+               clear_events (SessionEvent::PunchOut);
                auto_punch_location_changed (0);
        }
 
@@ -1010,7 +1034,7 @@ Session::set_auto_loop_location (Location* location)
                auto_loop_end_changed_connection.disconnect();
                auto_loop_changed_connection.disconnect();
                existing->set_auto_loop (false, this);
-               remove_event (existing->end(), Event::AutoLoop);
+               remove_event (existing->end(), SessionEvent::AutoLoop);
                auto_loop_location_changed (0);
        }
 
@@ -1031,9 +1055,12 @@ Session::set_auto_loop_location (Location* location)
        auto_loop_end_changed_connection.disconnect();
        auto_loop_changed_connection.disconnect();
 
-       auto_loop_start_changed_connection = location->start_changed.connect (mem_fun (this, &Session::auto_loop_changed));
-       auto_loop_end_changed_connection = location->end_changed.connect (mem_fun (this, &Session::auto_loop_changed));
-       auto_loop_changed_connection = location->changed.connect (mem_fun (this, &Session::auto_loop_changed));
+       auto_loop_start_changed_connection = location->start_changed.connect (
+                       mem_fun (this, &Session::auto_loop_changed));
+       auto_loop_end_changed_connection = location->end_changed.connect (
+                       mem_fun (this, &Session::auto_loop_changed));
+       auto_loop_changed_connection = location->changed.connect (
+                       mem_fun (this, &Session::auto_loop_changed));
 
        location->set_auto_loop (true, this);
 
@@ -1047,7 +1074,7 @@ Session::set_auto_loop_location (Location* location)
 }
 
 void
-Session::locations_added (Location* ignored)
+Session::locations_added (Location *)
 {
        set_dirty ();
 }
@@ -1106,7 +1133,7 @@ Session::enable_record ()
                _last_record_location = _transport_frame;
                deliver_mmc(MIDI::MachineControl::cmdRecordStrobe, _last_record_location);
 
-               if (Config->get_monitoring_model() == HardwareMonitoring && Config->get_auto_input()) {
+               if (Config->get_monitoring_model() == HardwareMonitoring && config.get_auto_input()) {
                        boost::shared_ptr<DiskstreamList> dsl = diskstreams.reader();
                        for (DiskstreamList::iterator i = dsl->begin(); i != dsl->end(); ++i) {
                                if ((*i)->record_enabled ()) {
@@ -1140,7 +1167,7 @@ Session::disable_record (bool rt_context, bool force)
                if (rt_context)
                        deliver_mmc (MIDI::MachineControl::cmdRecordExit, _transport_frame);
 
-               if (Config->get_monitoring_model() == HardwareMonitoring && Config->get_auto_input()) {
+               if (Config->get_monitoring_model() == HardwareMonitoring && config.get_auto_input()) {
                        boost::shared_ptr<DiskstreamList> dsl = diskstreams.reader();
 
                        for (DiskstreamList::iterator i = dsl->begin(); i != dsl->end(); ++i) {
@@ -1165,7 +1192,7 @@ Session::step_back_from_record ()
        if (g_atomic_int_get (&_record_status) == Recording) {
                g_atomic_int_set (&_record_status, Enabled);
 
-               if (Config->get_monitoring_model() == HardwareMonitoring && Config->get_auto_input()) {
+               if (Config->get_monitoring_model() == HardwareMonitoring && config.get_auto_input()) {
                        boost::shared_ptr<DiskstreamList> dsl = diskstreams.reader();
 
                        for (DiskstreamList::iterator i = dsl->begin(); i != dsl->end(); ++i) {
@@ -1190,7 +1217,7 @@ Session::maybe_enable_record ()
        save_state ("", true);
 
        if (_transport_speed) {
-               if (!Config->get_punch_in()) {
+               if (!config.get_punch_in()) {
                        enable_record ();
                }
        } else {
@@ -1201,12 +1228,12 @@ Session::maybe_enable_record ()
        set_dirty();
 }
 
-nframes_t
+nframes64_t
 Session::audible_frame () const
 {
-       nframes_t ret;
+       nframes64_t ret;
+       nframes64_t tf;
        nframes_t offset;
-       nframes_t tf;
 
        /* the first of these two possible settings for "offset"
           mean that the audible frame is stationary until
@@ -1236,7 +1263,7 @@ Session::audible_frame () const
        } else {
                tf = _transport_frame;
        }
-       
+
        ret = tf;
 
        if (!non_realtime_work_pending()) {
@@ -1255,8 +1282,8 @@ Session::audible_frame () const
                                if (tf < _last_roll_location + offset) {
                                        return _last_roll_location;
                                }
-                       } 
-                       
+                       }
+
 
                        /* forwards */
                        ret -= offset;
@@ -1313,7 +1340,6 @@ Session::set_block_size (nframes_t nframes)
        */
 
        {
-
                current_block_size = nframes;
 
                ensure_buffers(_scratch_buffers->available());
@@ -1339,7 +1365,7 @@ Session::set_block_size (nframes_t nframes)
 }
 
 void
-Session::set_default_fade (float steepness, float fade_msecs)
+Session::set_default_fade (float /*steepness*/, float /*fade_msecs*/)
 {
 #if 0
        nframes_t fade_frames;
@@ -1409,15 +1435,18 @@ trace_terminal (shared_ptr<Route> r1, shared_ptr<Route> rbase)
 
        /* make a copy of the existing list of routes that feed r1 */
 
-       set<shared_ptr<Route> > existing = r1->fed_by;
+       set<weak_ptr<Route> > existing = r1->fed_by;
 
        /* for each route that feeds r1, recurse, marking it as feeding
           rbase as well.
        */
 
-       for (set<shared_ptr<Route> >::iterator i = existing.begin(); i != existing.end(); ++i) {
-               r2 =* i;
-
+       for (set<weak_ptr<Route> >::iterator i = existing.begin(); i != existing.end(); ++i) {
+               if (!(r2 = (*i).lock ())) {
+                       /* (*i) went away, ignore it */
+                       continue;
+               }
+               
                /* r2 is a route that feeds r1 which somehow feeds base. mark
                   base as being fed by r2
                */
@@ -1428,7 +1457,7 @@ trace_terminal (shared_ptr<Route> r1, shared_ptr<Route> rbase)
 
                        /* 2nd level feedback loop detection. if r1 feeds or is fed by r2,
                           stop here.
-                        */
+                       */
 
                        if ((r1->fed_by.find (r2) != r1->fed_by.end()) && (r2->fed_by.find (r1) != r2->fed_by.end())) {
                                continue;
@@ -1511,7 +1540,7 @@ Session::resort_routes_using (shared_ptr<RouteList> r)
 }
 
 list<boost::shared_ptr<MidiTrack> >
-Session::new_midi_track (TrackMode mode, uint32_t how_many)
+Session::new_midi_track (TrackMode mode, RouteGroup* route_group, uint32_t how_many)
 {
        char track_name[32];
        uint32_t track_id = 0;
@@ -1529,7 +1558,7 @@ Session::new_midi_track (TrackMode mode, uint32_t how_many)
                shared_ptr<RouteList> r = routes.reader ();
 
                for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
-                       if (dynamic_cast<MidiTrack*>((*i).get()) != 0) {
+                       if (boost::dynamic_pointer_cast<MidiTrack>(*i) != 0) {
                                if (!(*i)->is_hidden()) {
                                        n++;
                                        //channels_used += (*i)->n_inputs().n_midi();
@@ -1571,7 +1600,13 @@ Session::new_midi_track (TrackMode mode, uint32_t how_many)
                try {
                        track = boost::shared_ptr<MidiTrack>((new MidiTrack (*this, track_name, Route::Flag (0), mode)));
 
-                       if (track->ensure_io (ChanCount(DataType::MIDI, 1), ChanCount(DataType::AUDIO, 1), false, this)) {
+                       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;
+                       }
+
+
+                       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;
                        }
@@ -1614,6 +1649,7 @@ Session::new_midi_track (TrackMode mode, uint32_t how_many)
                        */
 
                        track->midi_diskstream()->non_realtime_input_change();
+                       track->set_route_group (route_group, 0);
 
                        track->DiskstreamChanged.connect (mem_fun (this, &Session::resort_routes));
                        //track->set_remote_control_id (control_id);
@@ -1670,7 +1706,7 @@ Session::new_midi_track (TrackMode mode, uint32_t how_many)
 }
 
 list<boost::shared_ptr<AudioTrack> >
-Session::new_audio_track (int input_channels, int output_channels, TrackMode mode, uint32_t how_many)
+Session::new_audio_track (int input_channels, int output_channels, TrackMode mode, RouteGroup* route_group,  uint32_t how_many)
 {
        char track_name[32];
        uint32_t track_id = 0;
@@ -1687,7 +1723,7 @@ Session::new_audio_track (int input_channels, int output_channels, TrackMode mod
                shared_ptr<RouteList> r = routes.reader ();
 
                for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
-                       if (dynamic_cast<AudioTrack*>((*i).get()) != 0) {
+                       if (boost::dynamic_pointer_cast<AudioTrack>(*i) != 0) {
                                if (!(*i)->is_hidden()) {
                                        n++;
                                        channels_used += (*i)->n_inputs().n_audio();
@@ -1727,9 +1763,18 @@ Session::new_audio_track (int input_channels, int output_channels, TrackMode mod
                shared_ptr<AudioTrack> track;
 
                try {
-                       track = boost::shared_ptr<AudioTrack>((new AudioTrack (*this, track_name, Route::Flag (0), mode)));
+                       AudioTrack* at = new AudioTrack (*this, track_name, Route::Flag (0), mode);
+                       // boost_debug_shared_ptr_mark_interesting (at, typeid (at).name());
+                       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;
+                               goto failed;
+                       }
 
-                       if (track->ensure_io (ChanCount(DataType::AUDIO, input_channels), ChanCount(DataType::AUDIO, output_channels), false, this)) {
+                       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;
@@ -1747,7 +1792,7 @@ Session::new_audio_track (int input_channels, int output_channels, TrackMode mod
                                                port = physinputs[(channels_used+x)%nphysical_in];
                                        }
 
-                                       if (port.length() && track->connect_input (track->input (x), port, this)) {
+                                       if (port.length() && track->input()->connect (track->input()->nth(x), port, this)) {
                                                break;
                                        }
                                }
@@ -1757,18 +1802,17 @@ Session::new_audio_track (int input_channels, int output_channels, TrackMode mod
                                uint32_t nphysical_out = physoutputs.size();
 
                                for (uint32_t x = 0; x < track->n_outputs().n_audio(); ++x) {
-                                       
                                        port = "";
-                                       
+
                                        if (Config->get_output_auto_connect() & AutoConnectPhysical) {
                                                port = physoutputs[(channels_used+x)%nphysical_out];
                                        } else if (Config->get_output_auto_connect() & AutoConnectMaster) {
-                                               if (_master_out) {
-                                                       port = _master_out->input (x%_master_out->n_inputs().n_audio())->name();
+                                               if (_master_out && _master_out->n_inputs().n_audio() > 0) {
+                                                       port = _master_out->input()->nth (x % _master_out->input()->n_ports().n_audio())->name();
                                                }
                                        }
-                                       
-                                       if (port.length() && track->connect_output (track->output (x), port, this)) {
+
+                                       if (port.length() && track->output()->connect (track->output()->nth(x), port, this)) {
                                                break;
                                        }
                                }
@@ -1776,6 +1820,8 @@ Session::new_audio_track (int input_channels, int output_channels, TrackMode mod
 
                        channels_used += track->n_inputs ().n_audio();
 
+                       track->set_route_group (route_group, 0);
+
                        track->audio_diskstream()->non_realtime_input_change();
 
                        track->DiskstreamChanged.connect (mem_fun (this, &Session::resort_routes));
@@ -1805,7 +1851,7 @@ Session::new_audio_track (int input_channels, int output_channels, TrackMode mod
 
                catch (AudioEngine::PortRegistrationFailure& pfe) {
 
-                       error << _("No more JACK ports are available. You will need to stop Ardour and restart JACK with ports if you need this many tracks.") << endmsg;
+                       error << pfe.what() << endmsg;
 
                        if (track) {
                                /* we need to get rid of this, since the track failed to be created */
@@ -1854,7 +1900,7 @@ Session::set_remote_control_ids ()
 
 
 RouteList
-Session::new_audio_route (int input_channels, int output_channels, uint32_t how_many)
+Session::new_audio_route (bool aux, int input_channels, int output_channels, RouteGroup* route_group, uint32_t how_many)
 {
        char bus_name[32];
        uint32_t bus_id = 1;
@@ -1906,9 +1952,9 @@ Session::new_audio_route (int input_channels, int output_channels, uint32_t how_
                } while (bus_id < (UINT_MAX-1));
 
                try {
-                       shared_ptr<Route> bus (new Route (*this, bus_name, -1, -1, -1, -1, Route::Flag(0), DataType::AUDIO));
+                       shared_ptr<Route> bus (new Route (*this, bus_name, Route::Flag(0), DataType::AUDIO));
 
-                       if (bus->ensure_io (ChanCount(DataType::AUDIO, input_channels), ChanCount(DataType::AUDIO, output_channels), false, this)) {
+                       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;
@@ -1916,21 +1962,24 @@ Session::new_audio_route (int input_channels, int output_channels, uint32_t how_
                        }
 
 
+                       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;
+                       }
 
-                       /*
-                       for (uint32_t x = 0; n_physical_audio_inputs && x < bus->n_inputs(); ++x) {
-                                       
+                       for (uint32_t x = 0; n_physical_audio_inputs && x < bus->input()->n_ports().n_audio(); ++x) {
                                port = "";
-                               
+
                                if (Config->get_input_auto_connect() & AutoConnectPhysical) {
                                        port = physinputs[((n+x)%n_physical_audio_inputs)];
-                               } 
-                               
-                               if (port.length() && bus->connect_input (bus->input (x), port, this)) {
+                               }
+
+                               if (port.length() && bus->input()->connect (bus->input()->nth (x), port, this)) {
                                        break;
                                }
                        }
-                       */
 
                        for (uint32_t x = 0; n_physical_audio_outputs && x < bus->n_outputs().n_audio(); ++x) {
                                port = "";
@@ -1939,20 +1988,25 @@ Session::new_audio_route (int input_channels, int output_channels, uint32_t how_
                                        port = physoutputs[((n+x)%n_physical_outputs)];
                                } else if (Config->get_output_auto_connect() & AutoConnectMaster) {
                                        if (_master_out) {
-                                               port = _master_out->input (x%_master_out->n_inputs().n_audio())->name();
+                                               port = _master_out->input()->nth (x%_master_out->input()->n_ports().n_audio())->name();
                                        }
                                }
 
-                               if (port.length() && bus->connect_output (bus->output (x), port, this)) {
+                               if (port.length() && bus->output()->connect (bus->output()->nth(x), port, this)) {
                                        break;
                                }
                        }
 
                        channels_used += bus->n_inputs ().n_audio();
 
+                       bus->set_route_group (route_group, 0);
                        bus->set_remote_control_id (control_id);
                        ++control_id;
 
+                       if (aux) {
+                               bus->add_internal_return ();
+                       }
+
                        ret.push_back (bus);
                }
 
@@ -1963,7 +2017,7 @@ Session::new_audio_route (int input_channels, int output_channels, uint32_t how_
                }
 
                catch (AudioEngine::PortRegistrationFailure& pfe) {
-                       error << _("No more JACK ports are available. You will need to stop Ardour and restart JACK with ports if you need this many tracks.") << endmsg;
+                       error << pfe.what() << endmsg;
                        goto failure;
                }
 
@@ -1980,6 +2034,95 @@ Session::new_audio_route (int input_channels, int output_channels, uint32_t how_
 
 }
 
+RouteList
+Session::new_route_from_template (uint32_t how_many, const std::string& template_path)
+{
+       char name[32];
+       RouteList ret;
+       uint32_t control_id;
+       XMLTree tree;
+       uint32_t number = 1;
+
+       if (!tree.read (template_path.c_str())) {
+               return ret;
+       }
+
+       XMLNode* node = tree.root();
+
+       control_id = ntracks() + nbusses() + 1;
+
+       while (how_many) {
+
+               XMLNode node_copy (*node); // make a copy so we can change the name if we need to
+
+               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 */
+
+               do {
+                       snprintf (name, sizeof (name), "%s %" PRIu32, node_name.c_str(), number);
+
+                       number++;
+
+                       if (route_by_name (name) == 0) {
+                               break;
+                       }
+
+               } while (number < UINT_MAX);
+
+               if (number == UINT_MAX) {
+                       fatal << _("Session: UINT_MAX routes? impossible!") << endmsg;
+                       /*NOTREACHED*/
+               }
+
+               IO::set_name_in_state (*node_copy.children().front(), name);
+
+               Track::zero_diskstream_id_in_xml (node_copy);
+
+               try {
+                       shared_ptr<Route> route (XMLRouteFactory (node_copy, 3000));
+           
+                       if (route == 0) {
+                               error << _("Session: cannot create track/bus from template description") << endmsg;
+                               goto out;
+                       }
+
+                       if (boost::dynamic_pointer_cast<Track>(route)) {
+                               /* force input/output change signals so that the new diskstream
+                                  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);
+                       }
+
+                       route->set_remote_control_id (control_id);
+                       ++control_id;
+
+                       ret.push_back (route);
+               }
+
+               catch (failed_constructor &err) {
+                       error << _("Session: could not create new route from template") << endmsg;
+                       goto out;
+               }
+
+               catch (AudioEngine::PortRegistrationFailure& pfe) {
+                       error << pfe.what() << endmsg;
+                       goto out;
+               }
+
+               --how_many;
+       }
+
+  out:
+       if (!ret.empty()) {
+               add_routes (ret, true);
+       }
+
+       return ret;
+}
+
 void
 Session::add_routes (RouteList& new_routes, bool save)
 {
@@ -1987,17 +2130,29 @@ Session::add_routes (RouteList& new_routes, bool save)
                RCUWriter<RouteList> writer (routes);
                shared_ptr<RouteList> r = writer.get_copy ();
                r->insert (r->end(), new_routes.begin(), new_routes.end());
-               resort_routes_using (r);
+
+
+               /* if there is no control out and we're not in the middle of loading,
+                  resort the graph here. if there is a control out, we will resort
+                  toward the end of this method. if we are in the middle of loading,
+                  we will resort when done.
+               */
+
+               if (!_control_out && IO::connecting_legal) {
+                       resort_routes_using (r);
+               }
        }
 
        for (RouteList::iterator x = new_routes.begin(); x != new_routes.end(); ++x) {
 
                boost::weak_ptr<Route> wpr (*x);
 
+               (*x)->listen_changed.connect (sigc::bind (mem_fun (*this, &Session::route_listen_changed), wpr));
                (*x)->solo_changed.connect (sigc::bind (mem_fun (*this, &Session::route_solo_changed), wpr));
                (*x)->mute_changed.connect (mem_fun (*this, &Session::route_mute_changed));
-               (*x)->output_changed.connect (mem_fun (*this, &Session::set_worst_io_latencies_x));
-               (*x)->processors_changed.connect (bind (mem_fun (*this, &Session::update_latency_compensation), false, false));
+               (*x)->output()->changed.connect (mem_fun (*this, &Session::set_worst_io_latencies_x));
+               (*x)->processors_changed.connect (mem_fun (*this, &Session::route_processors_changed));
+               (*x)->route_group_changed.connect (hide (mem_fun (*this, &Session::route_group_changed)));
 
                if ((*x)->is_master()) {
                        _master_out = (*x);
@@ -2010,16 +2165,16 @@ Session::add_routes (RouteList& new_routes, bool save)
 
        if (_control_out && IO::connecting_legal) {
 
-               vector<string> cports;
-               uint32_t ni = _control_out->n_inputs().n_audio();
-
-               for (uint32_t n = 0; n < ni; ++n) {
-                       cports.push_back (_control_out->input(n)->name());
-               }
-
                for (RouteList::iterator x = new_routes.begin(); x != new_routes.end(); ++x) {
-                       (*x)->set_control_outs (cports);
+                       if ((*x)->is_control() || (*x)->is_master()) {
+                               continue;
+                       }
+                       (*x)->listen_via (_control_out,
+                                         (Config->get_listen_position() == AfterFaderListen ? PostFader : PreFader),
+                                         false, false);
                }
+
+               resort_routes ();
        }
 
        set_dirty();
@@ -2031,6 +2186,97 @@ Session::add_routes (RouteList& new_routes, bool save)
        RouteAdded (new_routes); /* EMIT SIGNAL */
 }
 
+void
+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);
+                       }
+               }
+       }
+}
+
+void
+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);
+                       }
+               }
+       }
+}
+
+void
+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());
+                       }
+               }
+       }
+}
+
+void
+Session::globally_add_internal_sends (boost::shared_ptr<Route> dest, Placement p)
+{
+       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)) {
+                       t->push_back (*i);
+               }
+       }
+
+       add_internal_sends (dest, p, t);
+}
+
+void
+Session::add_internal_sends (boost::shared_ptr<Route> dest, Placement p, boost::shared_ptr<RouteList> senders)
+{
+       if (dest->is_control() || dest->is_master()) {
+               return;
+       }
+
+       if (!dest->internal_return()) {
+               dest->add_internal_return();
+       }
+
+       for (RouteList::iterator i = senders->begin(); i != senders->end(); ++i) {
+
+               if ((*i)->is_control() || (*i)->is_master() || (*i) == dest) {
+                       continue;
+               }
+
+               (*i)->listen_via (dest, p, true, true);
+       }
+
+       graph_reordered ();
+}
+
 void
 Session::add_diskstream (boost::shared_ptr<Diskstream> dstream)
 {
@@ -2046,9 +2292,11 @@ Session::add_diskstream (boost::shared_ptr<Diskstream> dstream)
                /* writer goes out of scope, copies ds back to main */
        }
 
-       dstream->PlaylistChanged.connect (sigc::bind (mem_fun (*this, &Session::diskstream_playlist_changed), dstream));
+       dstream->PlaylistChanged.connect (sigc::bind (mem_fun (*this, &Session::diskstream_playlist_changed), boost::weak_ptr<Diskstream> (dstream)));
        /* this will connect to future changes, and check the current length */
-       diskstream_playlist_changed (dstream);
+       diskstream_playlist_changed (boost::weak_ptr<Diskstream> (dstream));
+
+       dstream->RecordEnableChanged.connect (mem_fun (*this, &Session::update_have_rec_enabled_diskstream));
 
        dstream->prepare ();
 
@@ -2073,15 +2321,14 @@ Session::remove_route (shared_ptr<Route> route)
                }
 
                if (route == _control_out) {
-                       _control_out = shared_ptr<Route> ();
 
                        /* cancel control outs for all routes */
 
-                       vector<string> empty;
-
                        for (RouteList::iterator r = rs->begin(); r != rs->end(); ++r) {
-                               (*r)->set_control_outs (empty);
+                               (*r)->drop_listen (_control_out);
                        }
+
+                       _control_out.reset ();
                }
 
                update_route_solo_state ();
@@ -2089,10 +2336,10 @@ Session::remove_route (shared_ptr<Route> route)
                /* writer goes out of scope, forces route list update */
        }
 
-       Track* t;
+       boost::shared_ptr<Track> t;
        boost::shared_ptr<Diskstream> ds;
 
-       if ((t = dynamic_cast<Track*>(route.get())) != 0) {
+       if ((t = boost::dynamic_pointer_cast<Track>(route)) != 0) {
                ds = t->diskstream();
        }
 
@@ -2109,8 +2356,20 @@ Session::remove_route (shared_ptr<Route> route)
 
        // We need to disconnect the routes inputs and outputs
 
-       route->disconnect_inputs (0);
-       route->disconnect_outputs (0);
+       route->input()->disconnect (0);
+       route->output()->disconnect (0);
+
+       /* if the route had internal sends sending to it, remove them */
+       if (route->internal_return()) {
+
+               boost::shared_ptr<RouteList> r = routes.reader ();
+               for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
+                       boost::shared_ptr<Send> s = (*i)->internal_send_for (route);
+                       if (s) {
+                               (*i)->remove_processor (s);
+                       }
+               }
+       }       
 
        update_latency_compensation (false, false);
        set_dirty();
@@ -2135,239 +2394,126 @@ Session::remove_route (shared_ptr<Route> route)
 }
 
 void
-Session::route_mute_changed (void* src)
+Session::route_mute_changed (void* /*src*/)
 {
        set_dirty ();
 }
 
 void
-Session::route_solo_changed (void* src, boost::weak_ptr<Route> wpr)
+Session::route_listen_changed (void* /*src*/, boost::weak_ptr<Route> wpr)
 {
-       if (solo_update_disabled) {
-               // We know already
-               return;
-       }
-
-       bool is_track;
-       boost::shared_ptr<Route> route = wpr.lock ();
-
+       boost::shared_ptr<Route> route = wpr.lock();
        if (!route) {
-               /* should not happen */
                error << string_compose (_("programming error: %1"), X_("invalid route weak ptr passed to route_solo_changed")) << endmsg;
                return;
        }
 
-       is_track = (boost::dynamic_pointer_cast<AudioTrack>(route) != 0);
-
-       shared_ptr<RouteList> r = routes.reader ();
-
-       for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
-
-               /* soloing a track mutes all other tracks, soloing a bus mutes all other busses */
-
-               if (is_track) {
-
-                       /* don't mess with busses */
-
-                       if (dynamic_cast<Track*>((*i).get()) == 0) {
-                               continue;
-                       }
-
-               } else {
-
-                       /* don't mess with tracks */
-
-                       if (dynamic_cast<Track*>((*i).get()) != 0) {
-                               continue;
-                       }
-               }
-
-               if ((*i) != route &&
-                   ((*i)->mix_group () == 0 ||
-                    (*i)->mix_group () != route->mix_group () ||
-                    !route->mix_group ()->is_active())) {
-
-                       if ((*i)->soloed()) {
-
-                               /* if its already soloed, and solo latching is enabled,
-                                  then leave it as it is.
-                               */
-
-                               if (Config->get_solo_latched()) {
-                                       continue;
-                               }
-                       }
-
-                       /* do it */
-
-                       solo_update_disabled = true;
-                       (*i)->set_solo (false, src);
-                       solo_update_disabled = false;
-               }
-       }
-
-       bool something_soloed = false;
-       bool same_thing_soloed = false;
-       bool signal = false;
-
-        for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
-               if ((*i)->soloed()) {
-                       something_soloed = true;
-                       if (dynamic_cast<Track*>((*i).get())) {
-                               if (is_track) {
-                                       same_thing_soloed = true;
-                                       break;
-                               }
-                       } else {
-                               if (!is_track) {
-                                       same_thing_soloed = true;
-                                       break;
-                               }
-                       }
-                       break;
-               }
-       }
-
-       if (something_soloed != currently_soloing) {
-               signal = true;
-               currently_soloing = something_soloed;
-       }
-
-       modify_solo_mute (is_track, same_thing_soloed);
-
-       if (signal) {
-               SoloActive (currently_soloing); /* EMIT SIGNAL */
+       if (route->listening()) {
+               _listen_cnt++;
+       } else if (_listen_cnt > 0) {
+               _listen_cnt--;
        }
-
-       SoloChanged (); /* EMIT SIGNAL */
-
-       set_dirty();
 }
 
 void
-Session::update_route_solo_state ()
+Session::route_solo_changed (void* /*src*/, boost::weak_ptr<Route> wpr)
 {
-       bool mute = false;
-       bool is_track = false;
-       bool signal = false;
-
-       /* this is where we actually implement solo by changing
-          the solo mute setting of each track.
-       */
-
-       shared_ptr<RouteList> r = routes.reader ();
-
-       for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
-               if ((*i)->soloed()) {
-                       mute = true;
-                       if (dynamic_cast<Track*>((*i).get())) {
-                               is_track = true;
-                       }
-                       break;
-               }
-       }
-
-       if (mute != currently_soloing) {
-               signal = true;
-               currently_soloing = mute;
+       if (solo_update_disabled) {
+               // We know already
+               return;
        }
 
-       if (!is_track && !mute) {
-
-               /* nothing is soloed */
-
-               for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
-                       (*i)->set_solo_mute (false);
-               }
-
-               if (signal) {
-                       SoloActive (false);
-               }
+       boost::shared_ptr<Route> route = wpr.lock ();
 
+       if (!route) {
+               /* should not happen */
+               error << string_compose (_("programming error: %1"), X_("invalid route weak ptr passed to route_solo_changed")) << endmsg;
                return;
        }
 
-       modify_solo_mute (is_track, mute);
+       shared_ptr<RouteList> r = routes.reader ();
+       int32_t delta;
 
-       if (signal) {
-               SoloActive (currently_soloing);
+       if (route->self_soloed()) {
+               delta = 1;
+       } else {
+               delta = -1;
        }
-}
 
-void
-Session::modify_solo_mute (bool is_track, bool mute)
-{
-       shared_ptr<RouteList> r = routes.reader ();
+       /* now mod the solo level of all other routes except master & control outs
+          so that they will be silent if appropriate.
+       */
 
-        for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
+       solo_update_disabled = true;
 
-               if (is_track) {
+       for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
+               bool via_sends_only;
 
-                       /* only alter track solo mute */
 
-                       if (dynamic_cast<Track*>((*i).get())) {
-                               if ((*i)->soloed()) {
-                                       (*i)->set_solo_mute (!mute);
-                               } else {
-                                       (*i)->set_solo_mute (mute);
-                               }
+               if ((*i) == route || !(*i)->solo_isolated() || !(*i)->is_master() || !(*i)->is_control() || (*i)->is_hidden()) {
+                       continue;
+               } else if ((*i)->feeds (route, &via_sends_only)) {
+                       if (!via_sends_only) {
+                               (*i)->mod_solo_by_others (delta);
                        }
+               } 
+       }
 
-               } else {
-
-                       /* only alter bus solo mute */
+       /* make sure master is never muted by solo */
 
-                       if (!dynamic_cast<Track*>((*i).get())) {
+       if (_master_out && route != _master_out && _master_out->soloed_by_others() == 0 && !_master_out->soloed()) {
+               _master_out->mod_solo_by_others (1);
+       }
+       /* ditto for control outs make sure master is never muted by solo */
 
-                               if ((*i)->soloed()) {
+       if (_control_out && route != _control_out && _control_out && _control_out->soloed_by_others() == 0) {
+               _control_out->mod_solo_by_others (1);
+       }
 
-                                       (*i)->set_solo_mute (false);
+       solo_update_disabled = false;
+       update_route_solo_state (r);
+       SoloChanged (); /* EMIT SIGNAL */
+       set_dirty();
+}
 
-                               } else {
+void
+Session::update_route_solo_state (boost::shared_ptr<RouteList> r)
+{
+       /* now figure out if anything that matters is soloed */
 
-                                       /* don't mute master or control outs
-                                          in response to another bus solo
-                                       */
+       bool something_soloed = false;
 
-                                       if ((*i) != _master_out &&
-                                           (*i) != _control_out) {
-                                               (*i)->set_solo_mute (mute);
-                                       }
-                               }
-                       }
+       if (!r) {
+               r = routes.reader();
+       }
 
+       for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
+               if (!(*i)->is_master() && !(*i)->is_control() && !(*i)->is_hidden() && (*i)->self_soloed()) {
+                       something_soloed = true;
+                       break;
                }
        }
-}
-
-
-void
-Session::catch_up_on_solo ()
-{
-       /* this is called after set_state() to catch the full solo
-          state, which can't be correctly determined on a per-route
-          basis, but needs the global overview that only the session
-          has.
-       */
-       update_route_solo_state();
-}      
 
-void
-Session::catch_up_on_solo_mute_override ()
-{
-       if (Config->get_solo_model() != InverseMute) {
-               return;
+       if (something_soloed != _non_soloed_outs_muted) {
+               _non_soloed_outs_muted = something_soloed;
+               SoloActive (_non_soloed_outs_muted); /* EMIT SIGNAL */
        }
+}
 
-       /* this is called whenever the param solo-mute-override is
-          changed.
-       */
+boost::shared_ptr<RouteList> 
+Session::get_routes_with_internal_returns() const
+{
        shared_ptr<RouteList> r = routes.reader ();
+       boost::shared_ptr<RouteList> rl (new RouteList);
 
        for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
-               (*i)->catch_up_on_solo_mute_override ();
+               if ((*i)->internal_return ()) {
+                       rl->push_back (*i);
+               }
        }
-}      
+       return rl;
+}
 
 shared_ptr<Route>
 Session::route_by_name (string name)
@@ -2680,17 +2826,17 @@ void
 Session::update_region_name_map (boost::shared_ptr<Region> region)
 {
        string::size_type last_period = region->name().find_last_of ('.');
-       
+
        if (last_period != string::npos && last_period < region->name().length() - 1) {
-               
+
                string base = region->name().substr (0, last_period);
                string number = region->name().substr (last_period+1);
                map<string,uint32_t>::iterator x;
-               
+
                /* note that if there is no number, we get zero from atoi,
                   which is just fine
                */
-               
+
                region_name_map[base] = atoi (number);
        }
 }
@@ -2769,13 +2915,6 @@ Session::find_whole_file_parent (boost::shared_ptr<Region const> child)
        return boost::shared_ptr<Region> ();
 }
 
-void
-Session::find_equivalent_playlist_regions (boost::shared_ptr<Region> region, vector<boost::shared_ptr<Region> >& result)
-{
-       for (PlaylistList::iterator i = playlists.begin(); i != playlists.end(); ++i)
-               (*i)->get_region_list_equivalent_regions (region, result);
-}
-
 int
 Session::destroy_region (boost::shared_ptr<Region> region)
 {
@@ -3047,7 +3186,7 @@ Session::change_source_path_by_name (string path, string oldname, string newname
        return path;
 }
 
-/** Return the full path (in some session directory) for a new embedded source.
+/** Return the full path (in some session directory) for a new within-session source.
  * \a name must be a session-unique name that does not contain slashes
  *         (e.g. as returned by new_*_source_name)
  */
@@ -3168,16 +3307,16 @@ Session::new_audio_source_name (const string& base, uint32_t nchan, uint32_t cha
        return Glib::path_get_basename(buf);
 }
 
-/** Create a new embedded audio source */
+/** Create a new within-session audio source */
 boost::shared_ptr<AudioFileSource>
 Session::create_audio_source_for_session (AudioDiskstream& ds, uint32_t chan, bool destructive)
 {
        const size_t n_chans = ds.n_channels().n_audio();
        const string name    = new_audio_source_name (ds.name(), n_chans, chan, destructive);
        const string path    = new_source_path_from_name(DataType::AUDIO, name);
+
        return boost::dynamic_pointer_cast<AudioFileSource> (
-                       SourceFactory::createWritable (
-                                       DataType::AUDIO, *this, path, true, destructive, frame_rate()));
+               SourceFactory::createWritable (DataType::AUDIO, *this, path, destructive, frame_rate()));
 }
 
 /** Return a unique name based on \a base for a new internal MIDI source */
@@ -3229,7 +3368,7 @@ Session::new_midi_source_name (const string& base)
 }
 
 
-/** Create a new embedded MIDI source */
+/** Create a new within-session MIDI source */
 boost::shared_ptr<MidiSource>
 Session::create_midi_source_for_session (MidiDiskstream& ds)
 {
@@ -3238,45 +3377,9 @@ Session::create_midi_source_for_session (MidiDiskstream& ds)
 
        return boost::dynamic_pointer_cast<SMFSource> (
                        SourceFactory::createWritable (
-                                       DataType::MIDI, *this, path, true, false, frame_rate()));
-}
-
-
-/* Playlist management */
-
-boost::shared_ptr<Playlist>
-Session::playlist_by_name (string name)
-{
-       Glib::Mutex::Lock lm (playlist_lock);
-       for (PlaylistList::iterator i = playlists.begin(); i != playlists.end(); ++i) {
-               if ((*i)->name() == name) {
-                       return* i;
-               }
-       }
-       for (PlaylistList::iterator i = unused_playlists.begin(); i != unused_playlists.end(); ++i) {
-               if ((*i)->name() == name) {
-                       return* i;
-               }
-       }
-
-       return boost::shared_ptr<Playlist>();
+                                       DataType::MIDI, *this, path, false, frame_rate()));
 }
 
-void
-Session::unassigned_playlists (std::list<boost::shared_ptr<Playlist> > & list)
-{
-       Glib::Mutex::Lock lm (playlist_lock);
-       for (PlaylistList::iterator i = playlists.begin(); i != playlists.end(); ++i) {
-               if (!(*i)->get_orig_diskstream_id().to_s().compare ("0")) {
-                       list.push_back (*i);
-               }
-       }
-       for (PlaylistList::iterator i = unused_playlists.begin(); i != unused_playlists.end(); ++i) {
-               if (!(*i)->get_orig_diskstream_id().to_s().compare ("0")) {
-                       list.push_back (*i);
-               }
-       }
-}
 
 void
 Session::add_playlist (boost::shared_ptr<Playlist> playlist, bool unused)
@@ -3285,13 +3388,9 @@ Session::add_playlist (boost::shared_ptr<Playlist> playlist, bool unused)
                return;
        }
 
-       {
-               Glib::Mutex::Lock lm (playlist_lock);
-               if (find (playlists.begin(), playlists.end(), playlist) == playlists.end()) {
-                       playlists.insert (playlists.begin(), playlist);
-                       playlist->InUse.connect (sigc::bind (mem_fun (*this, &Session::track_playlist), boost::weak_ptr<Playlist>(playlist)));
-                       playlist->GoingAway.connect (sigc::bind (mem_fun (*this, &Session::remove_playlist), boost::weak_ptr<Playlist>(playlist)));
-               }
+       bool existing = playlists->add (playlist);
+       if (!existing) {
+               playlist->GoingAway.connect (sigc::bind (mem_fun (*this, &Session::remove_playlist), boost::weak_ptr<Playlist>(playlist)));
        }
 
        if (unused) {
@@ -3299,61 +3398,6 @@ Session::add_playlist (boost::shared_ptr<Playlist> playlist, bool unused)
        }
 
        set_dirty();
-
-       PlaylistAdded (playlist); /* EMIT SIGNAL */
-}
-
-void
-Session::get_playlists (vector<boost::shared_ptr<Playlist> >& s)
-{
-       {
-               Glib::Mutex::Lock lm (playlist_lock);
-               for (PlaylistList::iterator i = playlists.begin(); i != playlists.end(); ++i) {
-                       s.push_back (*i);
-               }
-               for (PlaylistList::iterator i = unused_playlists.begin(); i != unused_playlists.end(); ++i) {
-                       s.push_back (*i);
-               }
-       }
-}
-
-void
-Session::track_playlist (bool inuse, boost::weak_ptr<Playlist> wpl)
-{
-       boost::shared_ptr<Playlist> pl(wpl.lock());
-
-       if (!pl) {
-               return;
-       }
-
-       PlaylistList::iterator x;
-
-       if (pl->hidden()) {
-               /* its not supposed to be visible */
-               return;
-       }
-
-       {
-               Glib::Mutex::Lock lm (playlist_lock);
-
-               if (!inuse) {
-
-                       unused_playlists.insert (pl);
-
-                       if ((x = playlists.find (pl)) != playlists.end()) {
-                               playlists.erase (x);
-                       }
-
-
-               } else {
-
-                       playlists.insert (pl);
-
-                       if ((x = unused_playlists.find (pl)) != unused_playlists.end()) {
-                               unused_playlists.erase (x);
-                       }
-               }
-       }
 }
 
 void
@@ -3369,40 +3413,23 @@ Session::remove_playlist (boost::weak_ptr<Playlist> weak_playlist)
                return;
        }
 
-       {
-               Glib::Mutex::Lock lm (playlist_lock);
-
-               PlaylistList::iterator i;
-
-               i = find (playlists.begin(), playlists.end(), playlist);
-               if (i != playlists.end()) {
-                       playlists.erase (i);
-               }
-
-               i = find (unused_playlists.begin(), unused_playlists.end(), playlist);
-               if (i != unused_playlists.end()) {
-                       unused_playlists.erase (i);
-               }
-
-       }
+       playlists->remove (playlist);
 
        set_dirty();
-
-       PlaylistRemoved (playlist); /* EMIT SIGNAL */
 }
 
 void
 Session::set_audition (boost::shared_ptr<Region> r)
 {
        pending_audition_region = r;
-       post_transport_work = PostTransportWork (post_transport_work | PostTransportAudition);
-       schedule_butler_transport_work ();
+       add_post_transport_work (PostTransportAudition);
+       _butler->schedule_transport_work ();
 }
 
 void
 Session::audition_playlist ()
 {
-       Event* ev = new Event (Event::Audition, Event::Add, Event::Immediate, 0, 0.0);
+       SessionEvent* ev = new SessionEvent (SessionEvent::Audition, SessionEvent::Add, SessionEvent::Immediate, 0, 0.0);
        ev->region.reset ();
        queue_event (ev);
 }
@@ -3422,7 +3449,7 @@ Session::non_realtime_set_audition ()
 void
 Session::audition_region (boost::shared_ptr<Region> r)
 {
-       Event* ev = new Event (Event::Audition, Event::Add, Event::Immediate, 0, 0.0);
+       SessionEvent* ev = new SessionEvent (SessionEvent::Audition, SessionEvent::Add, SessionEvent::Immediate, 0, 0.0);
        ev->region = r;
        queue_event (ev);
 }
@@ -3503,6 +3530,20 @@ Session::set_all_solo (bool yn)
        set_dirty();
 }
 
+void
+Session::set_all_listen (bool yn)
+{
+       shared_ptr<RouteList> r = routes.reader ();
+
+       for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
+               if (!(*i)->is_hidden()) {
+                       (*i)->set_listen (yn, this);
+               }
+       }
+
+       set_dirty();
+}
+
 void
 Session::set_all_mute (bool yn)
 {
@@ -3536,10 +3577,10 @@ void
 Session::graph_reordered ()
 {
        /* don't do this stuff if we are setting up connections
-          from a set_state() call or creating new tracks.
+          from a set_state() call or creating new tracks. Ditto for deletion.
        */
 
-       if (_state_of_the_state & InitialConnecting) {
+       if (_state_of_the_state & (InitialConnecting|Deletion)) {
                return;
        }
 
@@ -3565,12 +3606,20 @@ Session::graph_reordered ()
 void
 Session::record_disenable_all ()
 {
+       if (!writable()) {
+               return;
+       }
+
        record_enable_change_all (false);
 }
 
 void
 Session::record_enable_all ()
 {
+       if (!writable()) {
+               return;
+       }
+
        record_enable_change_all (true);
 }
 
@@ -3578,38 +3627,39 @@ void
 Session::record_enable_change_all (bool yn)
 {
        shared_ptr<RouteList> r = routes.reader ();
+       RouteList* tracks = new RouteList;
 
        for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
-               Track* at;
+               boost::shared_ptr<Track> t;
 
-               if ((at = dynamic_cast<Track*>((*i).get())) != 0) {
-                       at->set_record_enable (yn, this);
+               if (boost::dynamic_pointer_cast<Track>(*i) != 0) {
+                       tracks->push_back (*i);
                }
        }
 
-       /* since we don't keep rec-enable state, don't mark session dirty */
+       SessionEvent* ev = new SessionEvent (SessionEvent::SetRecordEnable, SessionEvent::Add, SessionEvent::Immediate, 0, 0.0, yn);
+
+       ev->routes = tracks;
+       ev->Complete.connect (mem_fun (*this, &Session::cleanup_event));
+       queue_event (ev);
 }
 
 void
-Session::add_processor (Processor* processor)
+Session::do_record_enable_change_all (RouteList* rl, bool yn)
 {
-       Send* send;
-       PortInsert* port_insert;
-       PluginInsert* plugin_insert;
+       for (RouteList::iterator i = rl->begin(); i != rl->end(); ++i) {
+               boost::shared_ptr<Track> t;
 
-       if ((port_insert = dynamic_cast<PortInsert *> (processor)) != 0) {
-               _port_inserts.insert (_port_inserts.begin(), port_insert);
-       } else if ((plugin_insert = dynamic_cast<PluginInsert *> (processor)) != 0) {
-               _plugin_inserts.insert (_plugin_inserts.begin(), plugin_insert);
-       } else if ((send = dynamic_cast<Send *> (processor)) != 0) {
-               _sends.insert (_sends.begin(), send);
-       } else {
-               fatal << _("programming error: unknown type of Insert created!") << endmsg;
-               /*NOTREACHED*/
+               if ((t = boost::dynamic_pointer_cast<Track>(*i)) != 0) {
+                       t->set_record_enable (yn, this);
+               }
        }
+}
 
+void
+Session::add_processor (Processor* processor)
+{
        processor->GoingAway.connect (sigc::bind (mem_fun (*this, &Session::remove_processor), processor));
-
        set_dirty();
 }
 
@@ -3617,26 +3667,15 @@ void
 Session::remove_processor (Processor* processor)
 {
        Send* send;
+       Return* retrn;
        PortInsert* port_insert;
-       PluginInsert* plugin_insert;
 
        if ((port_insert = dynamic_cast<PortInsert *> (processor)) != 0) {
-               list<PortInsert*>::iterator x = find (_port_inserts.begin(), _port_inserts.end(), port_insert);
-               if (x != _port_inserts.end()) {
-                       insert_bitset[port_insert->bit_slot()] = false;
-                       _port_inserts.erase (x);
-               }
-       } else if ((plugin_insert = dynamic_cast<PluginInsert *> (processor)) != 0) {
-               _plugin_inserts.remove (plugin_insert);
+               insert_bitset[port_insert->bit_slot()] = false;
        } else if ((send = dynamic_cast<Send *> (processor)) != 0) {
-               list<Send*>::iterator x = find (_sends.begin(), _sends.end(), send);
-               if (x != _sends.end()) {
-                       send_bitset[send->bit_slot()] = false;
-                       _sends.erase (x);
-               }
-       } else {
-               fatal << _("programming error: unknown type of Insert deleted!") << endmsg;
-               /*NOTREACHED*/
+               send_bitset[send->bit_slot()] = false;
+       } else if ((retrn = dynamic_cast<Return *> (processor)) != 0) {
+               return_bitset[retrn->bit_slot()] = false;
        }
 
        set_dirty();
@@ -3647,7 +3686,7 @@ Session::available_capture_duration ()
 {
        float sample_bytes_on_disk = 4.0; // keep gcc happy
 
-       switch (Config->get_native_file_data_format()) {
+       switch (config.get_native_file_data_format()) {
        case FormatFloat:
                sample_bytes_on_disk = 4.0;
                break;
@@ -3718,7 +3757,7 @@ shared_ptr<Bundle>
 Session::bundle_by_name (string name) const
 {
        boost::shared_ptr<BundleList> b = _bundles.reader ();
-       
+
        for (BundleList::const_iterator i = b->begin(); i != b->end(); ++i) {
                if ((*i)->name() == name) {
                        return* i;
@@ -3729,17 +3768,11 @@ Session::bundle_by_name (string name) const
 }
 
 void
-Session::tempo_map_changed (Change ignored)
+Session::tempo_map_changed (Change)
 {
        clear_clicks ();
 
-       for (PlaylistList::iterator i = playlists.begin(); i != playlists.end(); ++i) {
-               (*i)->update_after_tempo_map_change ();
-       }
-
-       for (PlaylistList::iterator i = unused_playlists.begin(); i != unused_playlists.end(); ++i) {
-               (*i)->update_after_tempo_map_change ();
-       }
+       playlists->update_after_tempo_map_change ();
 
        set_dirty ();
 }
@@ -3750,22 +3783,28 @@ Session::tempo_map_changed (Change ignored)
 void
 Session::ensure_buffers (ChanCount howmany)
 {
-       if (current_block_size == 0)
+       if (current_block_size == 0) {
                return; // too early? (is this ok?)
+       }
 
-       // We need at least 2 MIDI scratch buffers to mix/merge
-       if (howmany.n_midi() < 2)
-               howmany.set_midi(2);
-
-       // FIXME: JACK needs to tell us maximum MIDI buffer size
-       // Using nasty assumption (max # events == nframes) for now
-       _scratch_buffers->ensure_buffers(howmany, current_block_size);
-       _mix_buffers->ensure_buffers(howmany, current_block_size);
-       _silent_buffers->ensure_buffers(howmany, current_block_size);
+       for (DataType::iterator t = DataType::begin(); t != DataType::end(); ++t) {
+               size_t count = std::max(_scratch_buffers->available().get(*t), howmany.get(*t));
+               _scratch_buffers->ensure_buffers (*t, count, _engine.raw_buffer_size(*t));
+               _mix_buffers->ensure_buffers (*t, count, _engine.raw_buffer_size(*t));
+               _silent_buffers->ensure_buffers (*t, count, _engine.raw_buffer_size(*t));
+       }
 
        allocate_pan_automation_buffers (current_block_size, howmany.n_audio(), false);
 }
 
+void
+Session::ensure_buffer_set(BufferSet& buffers, const ChanCount& count)
+{
+       for (DataType::iterator t = DataType::begin(); t != DataType::end(); ++t) {
+               buffers.ensure_buffers(*t, count.get(*t), _engine.raw_buffer_size(*t));
+       }
+}
+
 uint32_t
 Session::next_insert_id ()
 {
@@ -3806,6 +3845,26 @@ Session::next_send_id ()
        }
 }
 
+uint32_t
+Session::next_return_id ()
+{
+       /* this doesn't really loop forever. just think about it */
+
+       while (true) {
+               for (boost::dynamic_bitset<uint32_t>::size_type n = 0; n < return_bitset.size(); ++n) {
+                       if (!return_bitset[n]) {
+                               return_bitset[n] = true;
+                               return n;
+
+                       }
+               }
+
+               /* none available, so resize and try again */
+
+               return_bitset.resize (return_bitset.size() + 16, false);
+       }
+}
+
 void
 Session::mark_send_id (uint32_t id)
 {
@@ -3818,6 +3877,18 @@ Session::mark_send_id (uint32_t id)
        send_bitset[id] = true;
 }
 
+void
+Session::mark_return_id (uint32_t id)
+{
+       if (id >= return_bitset.size()) {
+               return_bitset.resize (id+16, false);
+       }
+       if (return_bitset[id]) {
+               warning << string_compose (_("return ID %1 appears to be in use already"), id) << endmsg;
+       }
+       return_bitset[id] = true;
+}
+
 void
 Session::mark_insert_id (uint32_t id)
 {
@@ -3908,11 +3979,18 @@ Session::route_name_unique (string n) const
        return true;
 }
 
-uint32_t
-Session::n_playlists () const
+bool
+Session::route_name_internal (string n) const
 {
-       Glib::Mutex::Lock lm (playlist_lock);
-       return playlists.size();
+       if (auditioner && auditioner->name() == n) {
+               return true;
+       }
+
+       if (_click_io && _click_io->name() == n) {
+               return true;
+       }
+
+       return false;
 }
 
 void
@@ -3947,13 +4025,13 @@ Session::freeze (InterThreadInfo& itt)
 
        for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
 
-               Track *at;
+               boost::shared_ptr<Track> t;
 
-               if ((at = dynamic_cast<Track*>((*i).get())) != 0) {
+               if ((t = boost::dynamic_pointer_cast<Track>(*i)) != 0) {
                        /* XXX this is wrong because itt.progress will keep returning to zero at the start
                           of every track.
                        */
-                       at->freeze (itt);
+                       t->freeze (itt);
                }
        }
 
@@ -3961,8 +4039,9 @@ Session::freeze (InterThreadInfo& itt)
 }
 
 boost::shared_ptr<Region>
-Session::write_one_track (AudioTrack& track, nframes_t start, nframes_t end,   
-                         bool overwrite, vector<boost::shared_ptr<Source> >& srcs, InterThreadInfo& itt)
+Session::write_one_track (AudioTrack& track, nframes_t start, nframes_t end,
+                         bool /*overwrite*/, vector<boost::shared_ptr<Source> >& srcs,
+                         InterThreadInfo& itt, bool enable_processing)
 {
        boost::shared_ptr<Region> result;
        boost::shared_ptr<Playlist> playlist;
@@ -3987,7 +4066,9 @@ Session::write_one_track (AudioTrack& track, nframes_t start, nframes_t end,
        // any bigger than this seems to cause stack overflows in called functions
        const nframes_t chunk_size = (128 * 1024)/4;
 
-       g_atomic_int_set (&processing_prohibited, 1);
+       // block all process callback handling
+
+       block_processing ();
 
        /* call tree *MUST* hold route_lock */
 
@@ -4017,7 +4098,7 @@ 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, true, false, frame_rate()));
+                               SourceFactory::createWritable (DataType::AUDIO, *this, buf, false, frame_rate()));
                }
 
                catch (failed_constructor& err) {
@@ -4034,7 +4115,7 @@ Session::write_one_track (AudioTrack& track, nframes_t start, nframes_t end,
        to_do = len;
 
        /* create a set of reasonably-sized buffers */
-       buffers.ensure_buffers(nchans, chunk_size);
+       buffers.ensure_buffers(DataType::AUDIO, nchans.n_audio(), chunk_size);
        buffers.set_count(nchans);
 
        for (vector<boost::shared_ptr<Source> >::iterator src=srcs.begin(); src != srcs.end(); ++src) {
@@ -4047,7 +4128,7 @@ Session::write_one_track (AudioTrack& track, nframes_t start, nframes_t end,
 
                this_chunk = min (to_do, chunk_size);
 
-               if (track.export_stuff (buffers, start, this_chunk)) {
+               if (track.export_stuff (buffers, start, this_chunk, enable_processing)) {
                        goto out;
                }
 
@@ -4088,7 +4169,7 @@ Session::write_one_track (AudioTrack& track, nframes_t start, nframes_t end,
                /* construct a region to represent the bounced material */
 
                result = RegionFactory::create (srcs, 0,
-                               srcs.front()->length(srcs.front()->timeline_position()), 
+                               srcs.front()->length(srcs.front()->timeline_position()),
                                region_name_from_path (srcs.front()->name(), true));
        }
 
@@ -4100,7 +4181,7 @@ Session::write_one_track (AudioTrack& track, nframes_t start, nframes_t end,
                        if (afs) {
                                afs->mark_for_remove ();
                        }
-                       
+
                        (*src)->drop_references ();
                }
 
@@ -4113,7 +4194,7 @@ Session::write_one_track (AudioTrack& track, nframes_t start, nframes_t end,
                }
        }
 
-       g_atomic_int_set (&processing_prohibited, 0);
+       unblock_processing ();
 
        return result;
 }
@@ -4161,7 +4242,7 @@ Session::ntracks () const
        shared_ptr<RouteList> r = routes.reader ();
 
        for (RouteList::const_iterator i = r->begin(); i != r->end(); ++i) {
-               if (dynamic_cast<Track*> ((*i).get())) {
+               if (boost::dynamic_pointer_cast<Track> (*i)) {
                        ++n;
                }
        }
@@ -4176,7 +4257,7 @@ Session::nbusses () const
        shared_ptr<RouteList> r = routes.reader ();
 
        for (RouteList::const_iterator i = r->begin(); i != r->end(); ++i) {
-               if (dynamic_cast<Track*> ((*i).get()) == 0) {
+               if (boost::dynamic_pointer_cast<Track>(*i) == 0) {
                        ++n;
                }
        }
@@ -4197,7 +4278,7 @@ Session::compute_initial_length ()
 }
 
 void
-Session::sync_order_keys (const char* base)
+Session::sync_order_keys (std::string const & base)
 {
        if (!Config->get_sync_all_route_ordering()) {
                /* leave order keys as they are */
@@ -4214,3 +4295,116 @@ Session::sync_order_keys (const char* base)
 }
 
 
+/** @return true if there is at least one record-enabled diskstream, otherwise false */
+bool
+Session::have_rec_enabled_diskstream () const
+{
+       return g_atomic_int_get (&_have_rec_enabled_diskstream) == 1;
+}
+
+/** Update the state of our rec-enabled diskstreams flag */
+void
+Session::update_have_rec_enabled_diskstream ()
+{
+       boost::shared_ptr<DiskstreamList> dsl = diskstreams.reader ();
+       DiskstreamList::iterator i = dsl->begin ();
+       while (i != dsl->end () && (*i)->record_enabled () == false) {
+               ++i;
+       }
+
+       int const old = g_atomic_int_get (&_have_rec_enabled_diskstream);
+
+       g_atomic_int_set (&_have_rec_enabled_diskstream, i != dsl->end () ? 1 : 0);
+
+       if (g_atomic_int_get (&_have_rec_enabled_diskstream) != old) {
+               RecordStateChanged (); /* EMIT SIGNAL */
+       }
+}
+
+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_control_outs_at (p);
+       }
+}
+
+void
+Session::solo_control_mode_changed ()
+{
+       /* cancel all solo or all listen when solo control mode changes */
+
+       if (Config->get_solo_control_is_listen_control()) {
+               set_all_solo (false);
+       } else {
+               set_all_listen (false);
+       }
+}
+
+void
+Session::route_group_changed ()
+{
+       RouteGroupChanged (); /* EMIT SIGNAL */
+}
+
+vector<SyncSource>
+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);
+       } 
+
+       return ret;
+}
+
+boost::shared_ptr<RouteList>
+Session::get_routes_with_regions_at (nframes64_t const p) const
+{
+       shared_ptr<RouteList> r = routes.reader ();
+       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);
+               if (!tr) {
+                       continue;
+               }
+               
+               boost::shared_ptr<Diskstream> ds = tr->diskstream ();
+               if (!ds) {
+                       continue;
+               }
+
+               boost::shared_ptr<Playlist> pl = ds->playlist ();
+               if (!pl) {
+                       continue;
+               }
+               
+               if (pl->has_region_at (p)) {
+                       rl->push_back (*i);
+               }
+       }
+
+       return rl;
+}