session.h

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/*
  Copyright (C) 2000 Paul Davis

  This program is free software; you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation; either version 2 of the License, or
  (at your option) any later version.

  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program; if not, write to the Free Software
  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

*/

#ifndef __ardour_session_h__
#define __ardour_session_h__

#include "libardour-config.h"

#include <list>
#include <map>
#include <set>
#include <string>
#include <vector>
#include <stdint.h>

#include <boost/dynamic_bitset.hpp>
#include <boost/scoped_ptr.hpp>
#include <boost/weak_ptr.hpp>
#include <boost/utility.hpp>

#include <glibmm/threads.h>

#include <ltc.h>

#include "pbd/error.h"
#include "pbd/event_loop.h"
#include "pbd/rcu.h"
#include "pbd/statefuldestructible.h"
#include "pbd/signals.h"
#include "pbd/undo.h"

#include "evoral/types.hpp"

#include "midi++/types.h"
#include "midi++/mmc.h"

#include "timecode/time.h"

#include "ardour/ardour.h"
#include "ardour/chan_count.h"
#include "ardour/delivery.h"
#include "ardour/interthread_info.h"
#include "ardour/rc_configuration.h"
#include "ardour/session_configuration.h"
#include "ardour/session_event.h"
#include "ardour/location.h"
#include "ardour/interpolation.h"
#include "ardour/route_graph.h"


class XMLTree;
class XMLNode;
struct _AEffect;
typedef struct _AEffect AEffect;

namespace MIDI {
class Port;
class MachineControl;
class Parser;
}

namespace PBD {
class Controllable;
class ControllableDescriptor;
}

namespace Evoral {
class Curve;
}

namespace ARDOUR {

class Amp;
class AudioEngine;
class AudioFileSource;
class AudioRegion;
class AudioSource;
class AudioTrack;
class Auditioner;
class AutomationList;
class AuxInput;
class BufferSet;
class Bundle;
class Butler;
class Click;
class Diskstream;
class ExportHandler;
class ExportStatus;
class Graph;
class IO;
class IOProcessor;
class ImportStatus;
class MidiClockTicker;
class MidiControlUI;
class MidiPortManager;
class MidiPort;
class MidiRegion;
class MidiSource;
class MidiTrack;
class Playlist;
class PluginInsert;
class PluginInfo;
class Port;
class PortInsert;
class ProcessThread;
class Processor;
class Region;
class Return;
class Route;
class RouteGroup;
class SMFSource;
class Send;
class SceneChanger;
class SessionDirectory;
class SessionMetadata;
class SessionPlaylists;
class Slave;
class Source;
class Speakers;
class TempoMap;
class Track;
class WindowsVSTPlugin;

extern void setup_enum_writer ();

class LIBARDOUR_API Session : public PBD::StatefulDestructible, public PBD::ScopedConnectionList, public SessionEventManager
{
  public:
        enum RecordState {
                Disabled = 0,
                Enabled = 1,
                Recording = 2
        };

        /* a new session might have non-empty mix_template, an existing session should always have an empty one.
           the bus profile can be null if no master out bus is required.
        */

        Session (AudioEngine&,
                 const std::string& fullpath,
                 const std::string& snapshot_name,
                 BusProfile* bus_profile = 0,
                 std::string mix_template = "");

        virtual ~Session ();

        static int get_info_from_path (const std::string& xmlpath, float& sample_rate, SampleFormat& data_format);

        std::string path() const { return _path; }
        std::string name() const { return _name; }
        std::string snap_name() const { return _current_snapshot_name; }
        std::string raid_path () const;
        bool path_is_within_session (const std::string&);

        void set_snap_name ();

        bool writable() const { return _writable; }
        void set_dirty ();
        void set_clean ();
        bool dirty() const { return _state_of_the_state & Dirty; }
        void set_deletion_in_progress ();
        void clear_deletion_in_progress ();
        bool deletion_in_progress() const { return _state_of_the_state & Deletion; }
        PBD::Signal0<void> DirtyChanged;

        const SessionDirectory& session_directory () const { return *(_session_dir.get()); }

        static PBD::Signal1<void,std::string> Dialog;

        PBD::Signal0<void> BatchUpdateStart;
        PBD::Signal0<void> BatchUpdateEnd;

        int ensure_subdirs ();

        std::string automation_dir () const;  
        std::string analysis_dir () const;    
        std::string plugins_dir () const;     
        std::string externals_dir () const;   

        std::string peak_path (std::string) const;

        std::string peak_path_from_audio_path (std::string) const;
        bool audio_source_name_is_unique (const std::string& name);
        std::string format_audio_source_name (const std::string& legalized_base, uint32_t nchan, uint32_t chan, bool destructive, bool take_required, uint32_t cnt, bool related_exists);
        std::string new_audio_source_path_for_embedded (const std::string& existing_path);
        std::string new_audio_source_path (const std::string&, uint32_t nchans, uint32_t chan, bool destructive, bool take_required);
        std::string new_midi_source_path (const std::string&);
        RouteList new_route_from_template (uint32_t how_many, const std::string& template_path, const std::string& name);
        std::vector<std::string> get_paths_for_new_sources (bool allow_replacing, const std::string& import_file_path, uint32_t channels);

        int bring_all_sources_into_session (boost::function<void(uint32_t,uint32_t,std::string)> callback);

        void process (pframes_t nframes);

        BufferSet& get_silent_buffers (ChanCount count = ChanCount::ZERO);
        BufferSet& get_scratch_buffers (ChanCount count = ChanCount::ZERO, bool silence = true );
        BufferSet& get_route_buffers (ChanCount count = ChanCount::ZERO, bool silence = true);
        BufferSet& get_mix_buffers (ChanCount count = ChanCount::ZERO);

        bool have_rec_enabled_track () const;

        bool have_captured() const { return _have_captured; }

        void refill_all_track_buffers ();
        Butler* butler() { return _butler; }
        void butler_transport_work ();

        void refresh_disk_space ();

        int load_diskstreams_2X (XMLNode const &, int);

        int load_routes (const XMLNode&, int);
        boost::shared_ptr<RouteList> get_routes() const {
                return routes.reader ();
        }

        boost::shared_ptr<RouteList> get_tracks() const;
        boost::shared_ptr<RouteList> get_routes_with_internal_returns() const;
        boost::shared_ptr<RouteList> get_routes_with_regions_at (framepos_t const) const;

        uint32_t nroutes() const { return routes.reader()->size(); }
        uint32_t ntracks () const;
        uint32_t nbusses () const;

        boost::shared_ptr<BundleList> bundles () {
                return _bundles.reader ();
        }

        struct LIBARDOUR_API RoutePublicOrderSorter {
                bool operator() (boost::shared_ptr<Route>, boost::shared_ptr<Route> b);
        };

        void set_order_hint (int32_t order_hint) {_order_hint = order_hint;};
        void notify_remote_id_change ();
        void sync_order_keys ();

        template<class T> void foreach_route (T *obj, void (T::*func)(Route&), bool sort = true);
        template<class T> void foreach_route (T *obj, void (T::*func)(boost::shared_ptr<Route>), bool sort = true);
        template<class T, class A> void foreach_route (T *obj, void (T::*func)(Route&, A), A arg, bool sort = true);

        static char session_name_is_legal (const std::string&);
        bool io_name_is_legal (const std::string&);
        boost::shared_ptr<Route> route_by_name (std::string);
        boost::shared_ptr<Route> route_by_id (PBD::ID);
        boost::shared_ptr<Route> route_by_remote_id (uint32_t id);
        boost::shared_ptr<Track> track_by_diskstream_id (PBD::ID);
        void routes_using_input_from (const std::string& str, RouteList& rl);

        bool route_name_unique (std::string) const;
        bool route_name_internal (std::string) const;

        uint32_t track_number_decimals () const {
                return _track_number_decimals;
        }

        bool get_record_enabled() const {
                return (record_status () >= Enabled);
        }

        RecordState record_status() const {
                return (RecordState) g_atomic_int_get (&_record_status);
        }

        bool actively_recording () const {
                return record_status() == Recording;
        }

        bool record_enabling_legal () const;
        void maybe_enable_record ();
        void disable_record (bool rt_context, bool force = false);
        void step_back_from_record ();

        void maybe_write_autosave ();

        /* Emitted when all i/o connections are complete */

        PBD::Signal0<void> IOConnectionsComplete;

        /* Record status signals */

        PBD::Signal0<void> RecordStateChanged;

        /* Transport mechanism signals */

        PBD::Signal0<void> TransportStateChange;

        PBD::Signal1<void,framepos_t> PositionChanged; /* sent after any non-sequential motion */
        PBD::Signal1<void,framepos_t> Xrun;
        PBD::Signal0<void> TransportLooped;

        PBD::Signal0<void> Located;

        PBD::Signal1<void,RouteList&> RouteAdded;
        PBD::Signal1<void, RouteGroup *> RouteGroupPropertyChanged;
        PBD::Signal2<void, RouteGroup *, boost::weak_ptr<Route> > RouteAddedToRouteGroup;
        PBD::Signal2<void, RouteGroup *, boost::weak_ptr<Route> > RouteRemovedFromRouteGroup;

        /* Step Editing status changed */
        PBD::Signal1<void,bool> StepEditStatusChange;

        void queue_event (SessionEvent*);

        void request_roll_at_and_return (framepos_t start, framepos_t return_to);
        void request_bounded_roll (framepos_t start, framepos_t end);
        void request_stop (bool abort = false, bool clear_state = false);
        void request_locate (framepos_t frame, bool with_roll = false);

        void request_play_loop (bool yn, bool leave_rolling = false);
        bool get_play_loop () const { return play_loop; }

        framepos_t last_transport_start () const { return _last_roll_location; }
        void goto_end ();
        void goto_start ();
        void use_rf_shuttle_speed ();
        void allow_auto_play (bool yn);
        void request_transport_speed (double speed, bool as_default = false);
        void request_transport_speed_nonzero (double, bool as_default = false);
        void request_overwrite_buffer (Track *);
        void adjust_playback_buffering();
        void adjust_capture_buffering();
        void request_track_speed (Track *, double speed);
        void request_input_change_handling ();

        bool locate_pending() const { return static_cast<bool>(post_transport_work()&PostTransportLocate); }
        bool transport_locked () const;

        int wipe ();

        framepos_t current_end_frame () const;
        framepos_t current_start_frame () const;
        framecnt_t frame_rate () const { return _current_frame_rate; }
        framecnt_t nominal_frame_rate () const { return _nominal_frame_rate; }
        framecnt_t frames_per_hour () const { return _frames_per_hour; }

        double frames_per_timecode_frame() const { return _frames_per_timecode_frame; }
        framecnt_t timecode_frames_per_hour() const { return _timecode_frames_per_hour; }

        MIDI::byte get_mtc_timecode_bits() const {
                return mtc_timecode_bits;   /* encoding of SMTPE type for MTC */
        }

        double timecode_frames_per_second() const;
        bool timecode_drop_frames() const;

        /* Locations */

        Locations *locations() { return _locations; }

        PBD::Signal1<void,Location*>    auto_loop_location_changed;
        PBD::Signal1<void,Location*>    auto_punch_location_changed;
        PBD::Signal0<void>              locations_modified;

        void set_auto_punch_location (Location *);
        void set_auto_loop_location (Location *);
        void set_session_extents (framepos_t start, framepos_t end);
        int location_name(std::string& result, std::string base = std::string(""));

        pframes_t get_block_size()        const { return current_block_size; }
        framecnt_t worst_output_latency () const { return _worst_output_latency; }
        framecnt_t worst_input_latency ()  const { return _worst_input_latency; }
        framecnt_t worst_track_latency ()  const { return _worst_track_latency; }
        framecnt_t worst_playback_latency () const { return _worst_output_latency + _worst_track_latency; }
        
        struct SaveAs {
                std::string new_parent_folder;  /* parent folder where new session folder will be created */
                std::string new_name;           /* name of newly saved session */
                bool        switch_to;     /* true if we should be working on newly saved session after save-as; false otherwise */
                bool        include_media; /* true if the newly saved session should contain references to media */
                bool        copy_media;    /* true if media files (audio, media, etc) should be copied into newly saved session; false otherwise */
                bool        copy_external; /* true if external media should be consolidated into the newly saved session; false otherwise */

                std::string final_session_folder_name; /* filled in by * Session::save_as(), provides full path to newly saved session */
                
                /* emitted as we make progress. 3 arguments passed to signal
                 * handler:
                 *
                 *  1: percentage complete measured as a fraction (0-1.0) of
                 *     total data copying done.
                 *  2: number of files copied so far
                 *  3: total number of files to copy
                 *
                 * Handler should return true for save-as to continue, or false
                 * to stop (and remove all evidence of partial save-as).
                 */
                PBD::Signal3<bool,float,int64_t,int64_t> Progress;

                /* if save_as() returns non-zero, this string will indicate the reason why.
                 */
                std::string failure_message;
        };

        int save_as (SaveAs&);
        int save_state (std::string snapshot_name, bool pending = false, bool switch_to_snapshot = false, bool template_only = false);
        int restore_state (std::string snapshot_name);
        int save_template (std::string template_name);
        int save_history (std::string snapshot_name = "");
        int restore_history (std::string snapshot_name);
        void remove_state (std::string snapshot_name);
        void rename_state (std::string old_name, std::string new_name);
        void remove_pending_capture_state ();
        int rename (const std::string&);
        bool get_nsm_state () const { return _under_nsm_control; }
        void set_nsm_state (bool state) { _under_nsm_control = state; }
        bool save_default_options ();

        PBD::Signal1<void,std::string> StateSaved;
        PBD::Signal0<void> StateReady;

        /* emitted when session needs to be saved due to some internal
         * event or condition (i.e. not in response to a user request).
         *
         * Only one object should
         * connect to this signal and take responsibility.
         *
         * Argument is the snapshot name to use when saving.
         */
        PBD::Signal1<void,std::string> SaveSessionRequested; 

        /* emitted during a session save to allow other entities to add state, via
         * extra XML, to the session state 
         */
        PBD::Signal0<void> SessionSaveUnderway;

        std::vector<std::string> possible_states() const;
        static std::vector<std::string> possible_states (std::string path);

        XMLNode& get_state();
        int      set_state(const XMLNode& node, int version); // not idempotent
        XMLNode& get_template();

        void add_instant_xml (XMLNode&, bool write_to_config = true);
        XMLNode* instant_xml (const std::string& str);

        enum StateOfTheState {
                Clean = 0x0,
                Dirty = 0x1,
                CannotSave = 0x2,
                Deletion = 0x4,
                InitialConnecting = 0x8,
                Loading = 0x10,
                InCleanup = 0x20
        };

        StateOfTheState state_of_the_state() const { return _state_of_the_state; }

        class StateProtector {
                                                public:
                StateProtector (Session* s) : _session (s) {
                        g_atomic_int_inc (&s->_suspend_save);
                }
                ~StateProtector () {
                        if (g_atomic_int_dec_and_test (&_session->_suspend_save)) {
                                while (_session->_save_queued) {
                                        _session->_save_queued = false;
                                        _session->save_state ("");
                                }
                        }
                }
                                                private:
                Session * _session;
        };

        void add_route_group (RouteGroup *);
        void remove_route_group (RouteGroup&);
        void reorder_route_groups (std::list<RouteGroup*>);

        RouteGroup* route_group_by_name (std::string);
        RouteGroup& all_route_group() const;

        PBD::Signal1<void,RouteGroup*> route_group_added;
        PBD::Signal0<void>             route_group_removed;
        PBD::Signal0<void>             route_groups_reordered;

        void foreach_route_group (boost::function<void(RouteGroup*)> f) {
                for (std::list<RouteGroup *>::iterator i = _route_groups.begin(); i != _route_groups.end(); ++i) {
                        f (*i);
                }
        }

        std::list<RouteGroup*> const & route_groups () const {
                return _route_groups;
        }

        /* fundamental operations. duh. */

        std::list<boost::shared_ptr<AudioTrack> > new_audio_track (
                int input_channels,
                int output_channels,
                TrackMode mode = Normal,
                RouteGroup* route_group = 0,
                uint32_t how_many = 1,
                std::string name_template = ""
                );

        RouteList new_audio_route (
                int input_channels, int output_channels, RouteGroup* route_group, uint32_t how_many, std::string name_template = ""
                );

        std::list<boost::shared_ptr<MidiTrack> > new_midi_track (
                const ChanCount& input, const ChanCount& output,
                boost::shared_ptr<PluginInfo> instrument = boost::shared_ptr<PluginInfo>(),
                TrackMode mode = Normal, 
                RouteGroup* route_group = 0, uint32_t how_many = 1, std::string name_template = ""
                );

        void   remove_route (boost::shared_ptr<Route>);
        void   resort_routes ();
        void   resort_routes_using (boost::shared_ptr<RouteList>);

        AudioEngine & engine() { return _engine; }
        AudioEngine const & engine () const { return _engine; }

        /* Time */

        framepos_t transport_frame () const {return _transport_frame; }
        framepos_t record_location () const {return _last_record_location; }
        framepos_t audible_frame () const;
        framepos_t requested_return_frame() const { return _requested_return_frame; }
        void set_requested_return_frame(framepos_t return_to);

        enum PullupFormat {
                pullup_Plus4Plus1,
                pullup_Plus4,
                pullup_Plus4Minus1,
                pullup_Plus1,
                pullup_None,
                pullup_Minus1,
                pullup_Minus4Plus1,
                pullup_Minus4,
                pullup_Minus4Minus1
        };

        void sync_time_vars();

        void bbt_time (framepos_t when, Timecode::BBT_Time&);
        void timecode_to_sample(Timecode::Time& timecode, framepos_t& sample, bool use_offset, bool use_subframes) const;
        void sample_to_timecode(framepos_t sample, Timecode::Time& timecode, bool use_offset, bool use_subframes) const;
        void timecode_time (Timecode::Time &);
        void timecode_time (framepos_t when, Timecode::Time&);
        void timecode_time_subframes (framepos_t when, Timecode::Time&);

        void timecode_duration (framecnt_t, Timecode::Time&) const;
        void timecode_duration_string (char *, size_t len, framecnt_t) const;

        framecnt_t convert_to_frames (AnyTime const & position);
        framecnt_t any_duration_to_frames (framepos_t position, AnyTime const & duration);

        static PBD::Signal1<void, framepos_t> StartTimeChanged;
        static PBD::Signal1<void, framepos_t> EndTimeChanged;

        void   request_sync_source (Slave*);
        bool   synced_to_engine() const { return _slave && config.get_external_sync() && Config->get_sync_source() == Engine; }

        double transport_speed() const { return _transport_speed; }
        bool   transport_stopped() const { return _transport_speed == 0.0f; }
        bool   transport_rolling() const { return _transport_speed != 0.0f; }

        bool silent () { return _silent; }

        TempoMap&       tempo_map()       { return *_tempo_map; }
        const TempoMap& tempo_map() const { return *_tempo_map; }

        unsigned int    get_xrun_count () const {return _xrun_count; }
        void            reset_xrun_count () {_xrun_count = 0; }

        /* region info  */

        boost::shared_ptr<Region> find_whole_file_parent (boost::shared_ptr<Region const>) const;

        boost::shared_ptr<Region>      XMLRegionFactory (const XMLNode&, bool full);
        boost::shared_ptr<AudioRegion> XMLAudioRegionFactory (const XMLNode&, bool full);
        boost::shared_ptr<MidiRegion>  XMLMidiRegionFactory (const XMLNode&, bool full);

        /* source management */

        void import_files (ImportStatus&);
        bool sample_rate_convert (ImportStatus&, std::string infile, std::string& outfile);
        std::string build_tmp_convert_name (std::string file);

        boost::shared_ptr<ExportHandler> get_export_handler ();
        boost::shared_ptr<ExportStatus> get_export_status ();

        int start_audio_export (framepos_t position);

        PBD::Signal1<int, framecnt_t> ProcessExport;
        static PBD::Signal2<void,std::string, std::string> Exported;

        void add_source (boost::shared_ptr<Source>);
        void remove_source (boost::weak_ptr<Source>);

        void  cleanup_regions();
        int  cleanup_sources (CleanupReport&);
        int  cleanup_trash_sources (CleanupReport&);

        int destroy_sources (std::list<boost::shared_ptr<Source> >);

        int remove_last_capture ();

        static PBD::Signal1<int,uint32_t> AudioEngineSetupRequired;

        static PBD::Signal1<int,boost::shared_ptr<Playlist> >  AskAboutPlaylistDeletion;

        static PBD::Signal2<int, framecnt_t, framecnt_t> AskAboutSampleRateMismatch;

        static PBD::Signal0<int> AskAboutPendingState;

        boost::shared_ptr<AudioFileSource> create_audio_source_for_session (
                size_t, std::string const &, uint32_t, bool destructive);

        boost::shared_ptr<MidiSource> create_midi_source_for_session (std::string const &);
        boost::shared_ptr<MidiSource> create_midi_source_by_stealing_name (boost::shared_ptr<Track>);

        boost::shared_ptr<Source> source_by_id (const PBD::ID&);
        boost::shared_ptr<AudioFileSource> audio_source_by_path_and_channel (const std::string&, uint16_t) const;
        boost::shared_ptr<MidiSource> midi_source_by_path (const std::string&) const;
        uint32_t count_sources_by_origin (const std::string&);

        void add_playlist (boost::shared_ptr<Playlist>, bool unused = false);

        /* Curves and AutomationLists (TODO when they go away) */
        void add_automation_list(AutomationList*);

        /* auditioning */

        boost::shared_ptr<Auditioner> the_auditioner() { return auditioner; }
        void audition_playlist ();
        void audition_region (boost::shared_ptr<Region>);
        void cancel_audition ();
        bool is_auditioning () const;

        PBD::Signal1<void,bool> AuditionActive;

        /* flattening stuff */

        boost::shared_ptr<Region> write_one_track (Track&, framepos_t start, framepos_t end,
                                                   bool overwrite, std::vector<boost::shared_ptr<Source> >&, InterThreadInfo& wot,
                                                   boost::shared_ptr<Processor> endpoint,
                                                   bool include_endpoint, bool for_export, bool for_freeze);
        int freeze_all (InterThreadInfo&);

        /* session-wide solo/mute/rec-enable */

        bool soloing() const { return _non_soloed_outs_muted; }
        bool listening() const { return _listen_cnt > 0; }
        bool solo_isolated() const { return _solo_isolated_cnt > 0; }

        static const SessionEvent::RTeventCallback rt_cleanup;

        void set_solo (boost::shared_ptr<RouteList>, bool, SessionEvent::RTeventCallback after = rt_cleanup, bool group_override = false);
        void set_just_one_solo (boost::shared_ptr<Route>, bool, SessionEvent::RTeventCallback after = rt_cleanup);
        void cancel_solo_after_disconnect (boost::shared_ptr<Route>, bool upstream, SessionEvent::RTeventCallback after = rt_cleanup);
        void set_mute (boost::shared_ptr<RouteList>, bool, SessionEvent::RTeventCallback after = rt_cleanup, bool group_override = false);
        void set_listen (boost::shared_ptr<RouteList>, bool, SessionEvent::RTeventCallback after = rt_cleanup, bool group_override = false);
        void set_record_enabled (boost::shared_ptr<RouteList>, bool, SessionEvent::RTeventCallback after = rt_cleanup, bool group_override = false);
        void set_solo_isolated (boost::shared_ptr<RouteList>, bool, SessionEvent::RTeventCallback after = rt_cleanup, bool group_override = false);
        void set_monitoring (boost::shared_ptr<RouteList>, MonitorChoice, SessionEvent::RTeventCallback after = rt_cleanup, bool group_override = false);
        void set_exclusive_input_active (boost::shared_ptr<RouteList> rt, bool onoff, bool flip_others=false);

        PBD::Signal1<void,bool> SoloActive;
        PBD::Signal0<void> SoloChanged;
        PBD::Signal0<void> IsolatedChanged;

        /* monitor/master out */

        void add_monitor_section ();
        void reset_monitor_section ();
        void remove_monitor_section ();

        boost::shared_ptr<Route> monitor_out() const { return _monitor_out; }
        boost::shared_ptr<Route> master_out() const { return _master_out; }

        void globally_add_internal_sends (boost::shared_ptr<Route> dest, Placement p, bool);
        void globally_set_send_gains_from_track (boost::shared_ptr<Route> dest);
        void globally_set_send_gains_to_zero (boost::shared_ptr<Route> dest);
        void globally_set_send_gains_to_unity (boost::shared_ptr<Route> dest);
        void add_internal_sends (boost::shared_ptr<Route> dest, Placement p, boost::shared_ptr<RouteList> senders);
        void add_internal_send (boost::shared_ptr<Route>, int, boost::shared_ptr<Route>);
        void add_internal_send (boost::shared_ptr<Route>, boost::shared_ptr<Processor>, boost::shared_ptr<Route>);

        static void set_disable_all_loaded_plugins (bool yn) {
                _disable_all_loaded_plugins = yn;
        }
        static bool get_disable_all_loaded_plugins() {
                return _disable_all_loaded_plugins;
        }

        uint32_t next_send_id();
        uint32_t next_aux_send_id();
        uint32_t next_return_id();
        uint32_t next_insert_id();
        void mark_send_id (uint32_t);
        void mark_aux_send_id (uint32_t);
        void mark_return_id (uint32_t);
        void mark_insert_id (uint32_t);
        void unmark_send_id (uint32_t);
        void unmark_aux_send_id (uint32_t);
        void unmark_return_id (uint32_t);
        void unmark_insert_id (uint32_t);

        /* s/w "RAID" management */

        boost::optional<framecnt_t> available_capture_duration();

        /* I/O bundles */

        void add_bundle (boost::shared_ptr<Bundle>, bool emit_signal = true);
        void remove_bundle (boost::shared_ptr<Bundle>);
        boost::shared_ptr<Bundle> bundle_by_name (std::string) const;

        PBD::Signal0<void> BundleAddedOrRemoved;

        void midi_panic ();

        /* History (for editors, mixers, UIs etc.) */

        void undo (uint32_t n) {
                _history.undo (n);
        }

        void redo (uint32_t n) {
                _history.redo (n);
        }

        UndoHistory& history() { return _history; }

        uint32_t undo_depth() const { return _history.undo_depth(); }
        uint32_t redo_depth() const { return _history.redo_depth(); }
        std::string next_undo() const { return _history.next_undo(); }
        std::string next_redo() const { return _history.next_redo(); }

        void begin_reversible_command (const std::string& cmd_name);
        void begin_reversible_command (GQuark);
        void abort_reversible_command ();
        void commit_reversible_command (Command* cmd = 0);

        void add_command (Command *const cmd) {
                assert (_current_trans);
                _current_trans->add_command (cmd);
        }

        std::list<GQuark> const & current_operations () {
                return _current_trans_quarks;
        }

        bool operation_in_progress (GQuark) const;

        void add_commands (std::vector<Command*> const & cmds);

        std::map<PBD::ID,PBD::StatefulDestructible*> registry;

        // these commands are implemented in libs/ardour/session_command.cc
        Command* memento_command_factory(XMLNode* n);
        Command* stateful_diff_command_factory (XMLNode *);
        void register_with_memento_command_factory(PBD::ID, PBD::StatefulDestructible*);

        /* clicking */

        boost::shared_ptr<IO> click_io() { return _click_io; }
        boost::shared_ptr<Amp> click_gain() { return _click_gain; }

        /* disk, buffer loads */

        uint32_t playback_load ();
        uint32_t capture_load ();

        /* ranges */

        void request_play_range (std::list<AudioRange>*, bool leave_rolling = false);
        void request_cancel_play_range ();
        bool get_play_range () const { return _play_range; }

        void maybe_update_session_range (framepos_t, framepos_t);

        /* buffers for gain and pan */

        gain_t* gain_automation_buffer () const;
        gain_t* trim_automation_buffer () const;
        gain_t* send_gain_automation_buffer () const;
        pan_t** pan_automation_buffer () const;

        void ensure_buffer_set (BufferSet& buffers, const ChanCount& howmany);

        /* VST support */

        static int  vst_current_loading_id;
        static const char* vst_can_do_strings[];
        static const int vst_can_do_string_count;

        static intptr_t vst_callback (
                AEffect* effect,
                int32_t opcode,
                int32_t index,
                intptr_t value,
                void* ptr,
                float opt
                );
                        
        static PBD::Signal0<void> SendFeedback;

        /* Speakers */

        boost::shared_ptr<Speakers> get_speakers ();

        /* Controllables */

        boost::shared_ptr<PBD::Controllable> controllable_by_id (const PBD::ID&);
        boost::shared_ptr<PBD::Controllable> controllable_by_descriptor (const PBD::ControllableDescriptor&);

        void add_controllable (boost::shared_ptr<PBD::Controllable>);
        void remove_controllable (PBD::Controllable*);

        boost::shared_ptr<PBD::Controllable> solo_cut_control() const;

        SessionConfiguration config;

        bool exporting () const {
                return _exporting;
        }

        bool bounce_processing() const {
                return _bounce_processing_active;
        }

        /* this is a private enum, but setup_enum_writer() needs it,
           and i can't find a way to give that function
           friend access. sigh.
        */

        enum PostTransportWork {
                PostTransportStop               = 0x1,
                PostTransportDuration           = 0x2,
                PostTransportLocate             = 0x4,
                PostTransportRoll               = 0x8,
                PostTransportAbort              = 0x10,
                PostTransportOverWrite          = 0x20,
                PostTransportSpeed              = 0x40,
                PostTransportAudition           = 0x80,
                PostTransportReverse            = 0x100,
                PostTransportInputChange        = 0x200,
                PostTransportCurveRealloc       = 0x400,
                PostTransportClearSubstate      = 0x800,
                PostTransportAdjustPlaybackBuffering  = 0x1000,
                PostTransportAdjustCaptureBuffering   = 0x2000
        };

        enum SlaveState {
                Stopped,
                Waiting,
                Running
        };

        SlaveState slave_state() const { return _slave_state; }
        Slave* slave() const { return _slave; }

        boost::shared_ptr<SessionPlaylists> playlists;

        void send_mmc_locate (framepos_t);
        void queue_full_time_code () { _send_timecode_update = true; }
        void queue_song_position_pointer () { /* currently does nothing */ }

        bool step_editing() const { return (_step_editors > 0); }

        void request_suspend_timecode_transmission ();
        void request_resume_timecode_transmission ();
        bool timecode_transmission_suspended () const;

        std::vector<std::string> source_search_path(DataType) const;
        void ensure_search_path_includes (const std::string& path, DataType type);
        void remove_dir_from_search_path (const std::string& path, DataType type);

        std::list<std::string> unknown_processors () const;

        static PBD::Signal0<void> FeedbackDetected;

        static PBD::Signal0<void> SuccessfulGraphSort;

        /* handlers can return an integer value:
           0: config.set_audio_search_path() or config.set_midi_search_path() was used
           to modify the search path and we should try to find it again.
           1: quit entire session load
           2: as 0, but don't ask about other missing files
           3: don't ask about other missing files, and just mark this one missing
           -1: just mark this one missing
           any other value: as -1
        */
        static PBD::Signal3<int,Session*,std::string,DataType> MissingFile;

        static PBD::Signal0<void> Quit;

        static PBD::Signal2<void,std::string,std::string> VersionMismatch;

        SceneChanger* scene_changer() const { return _scene_changer; }

        boost::shared_ptr<Port> ltc_input_port() const;
        boost::shared_ptr<Port> ltc_output_port() const;

        boost::shared_ptr<IO> ltc_input_io() { return _ltc_input; }
        boost::shared_ptr<IO> ltc_output_io() { return _ltc_output; }

        MIDI::Port* midi_input_port () const;
        MIDI::Port* midi_output_port () const;
        MIDI::Port* mmc_output_port () const;
        MIDI::Port* mmc_input_port () const;

        MIDI::Port* scene_input_port () const;
        MIDI::Port* scene_output_port () const;

        boost::shared_ptr<MidiPort> scene_in () const;
        boost::shared_ptr<MidiPort> scene_out () const;
        
        boost::shared_ptr<MidiPort> midi_clock_output_port () const;
        boost::shared_ptr<MidiPort> midi_clock_input_port () const;
        boost::shared_ptr<MidiPort> mtc_output_port () const;
        boost::shared_ptr<MidiPort> mtc_input_port () const;
    
        MIDI::MachineControl& mmc() { return *_mmc; }

  protected:
        friend class AudioEngine;
        void set_block_size (pframes_t nframes);
        void set_frame_rate (framecnt_t nframes);
        void reconnect_existing_routes (bool withLock, bool reconnect_master = true, bool reconnect_inputs = true, bool reconnect_outputs = true);

  protected:
        friend class Route;
        void schedule_curve_reallocation ();
        void update_latency_compensation (bool force = false);

  private:
        int  create (const std::string& mix_template, BusProfile*);
        void destroy ();

        enum SubState {
                PendingDeclickIn      = 0x1,  
                PendingDeclickOut     = 0x2,  
                StopPendingCapture    = 0x4,
                PendingLoopDeclickIn  = 0x8,  
                PendingLoopDeclickOut = 0x10, 
                PendingLocate         = 0x20,
        };

        /* stuff used in process() should be close together to
           maximise cache hits
        */

        typedef void (Session::*process_function_type)(pframes_t);

        AudioEngine&            _engine;
        mutable gint             processing_prohibited;
        process_function_type    process_function;
        process_function_type    last_process_function;
        bool                    _bounce_processing_active;
        bool                     waiting_for_sync_offset;
        framecnt_t              _base_frame_rate;
        framecnt_t              _current_frame_rate;  //this includes video pullup offset
        framecnt_t              _nominal_frame_rate;  //ignores audioengine setting, "native" SR
        int                      transport_sub_state;
        mutable gint            _record_status;
        framepos_t              _transport_frame;
        Location*               _session_range_location; 
        Slave*                  _slave;
        bool                    _silent;

        // varispeed playback
        double                  _transport_speed;
        double                  _default_transport_speed;
        double                  _last_transport_speed;
        double                  _signalled_varispeed;
        double                  _target_transport_speed;
        CubicInterpolation       interpolation;

        bool                     auto_play_legal;
        framepos_t              _last_slave_transport_frame;
        framecnt_t               maximum_output_latency;
        framepos_t              _requested_return_frame;
        pframes_t                current_block_size;
        framecnt_t              _worst_output_latency;
        framecnt_t              _worst_input_latency;
        framecnt_t              _worst_track_latency;
        bool                    _have_captured;
        bool                    _non_soloed_outs_muted;
        uint32_t                _listen_cnt;
        uint32_t                _solo_isolated_cnt;
        bool                    _writable;
        bool                    _was_seamless;
        bool                    _under_nsm_control;
        unsigned int            _xrun_count;

        void initialize_latencies ();
        void set_worst_io_latencies ();
        void set_worst_playback_latency ();
        void set_worst_capture_latency ();
        void set_worst_io_latencies_x (IOChange, void *) {
                set_worst_io_latencies ();
        }
        void post_capture_latency ();
        void post_playback_latency ();

        void update_latency_compensation_proxy (void* ignored);

        void ensure_buffers (ChanCount howmany = ChanCount::ZERO);

        void process_scrub          (pframes_t);
        void process_without_events (pframes_t);
        void process_with_events    (pframes_t);
        void process_audition       (pframes_t);
        int  process_export         (pframes_t);
        int  process_export_fw      (pframes_t);

        void block_processing() { g_atomic_int_set (&processing_prohibited, 1); }
        void unblock_processing() { g_atomic_int_set (&processing_prohibited, 0); }
        bool processing_blocked() const { return g_atomic_int_get (&processing_prohibited); }

        static const framecnt_t bounce_chunk_size;

        /* slave tracking */

        static const int delta_accumulator_size = 25;
        int delta_accumulator_cnt;
        int32_t delta_accumulator[delta_accumulator_size];
        int32_t average_slave_delta;
        int  average_dir;
        bool have_first_delta_accumulator;

        SlaveState _slave_state;
        framepos_t slave_wait_end;

        void reset_slave_state ();
        bool follow_slave (pframes_t);
        void calculate_moving_average_of_slave_delta (int dir, framecnt_t this_delta);
        void track_slave_state (float slave_speed, framepos_t slave_transport_frame, framecnt_t this_delta);
        void follow_slave_silently (pframes_t nframes, float slave_speed);

        void switch_to_sync_source (SyncSource); /* !RT context */
        void drop_sync_source ();  /* !RT context */
        void use_sync_source (Slave*); /* RT context */

        bool post_export_sync;
        framepos_t post_export_position;

        bool _exporting;
        bool _export_started;
        bool _export_rolling;

        boost::shared_ptr<ExportHandler> export_handler;
        boost::shared_ptr<ExportStatus>  export_status;

        int  pre_export ();
        int  stop_audio_export ();
        void finalize_audio_export ();
        void finalize_export_internal (bool stop_freewheel);
        bool _pre_export_mmc_enabled;

        PBD::ScopedConnection export_freewheel_connection;

        void get_track_statistics ();
        int  process_routes (pframes_t, bool& need_butler);
        int  silent_process_routes (pframes_t, bool& need_butler);

        int get_transport_declick_required () {
                if (transport_sub_state & PendingDeclickIn) {
                        transport_sub_state &= ~PendingDeclickIn;
                        return 1;
                } else if (transport_sub_state & PendingDeclickOut) {
                        /* XXX: not entirely sure why we don't clear this */
                        return -1;
                } else if (transport_sub_state & PendingLoopDeclickOut) {
                        /* Return the declick out first ... */
                        transport_sub_state &= ~PendingLoopDeclickOut;
                        return -1;
                } else if (transport_sub_state & PendingLoopDeclickIn) {
                        /* ... then the declick in on the next call */
                        transport_sub_state &= ~PendingLoopDeclickIn;
                        return 1;
                } else {
                        return 0;
                }
        }

        bool maybe_stop (framepos_t limit);
        bool maybe_sync_start (pframes_t &);

        void check_declick_out ();

        std::string             _path;
        std::string             _name;
        bool                    _is_new;
        bool                    _send_qf_mtc;
        pframes_t               _pframes_since_last_mtc;
        bool                     session_midi_feedback;
        bool                     play_loop;
        bool                     loop_changing;
        framepos_t               last_loopend;

        boost::scoped_ptr<SessionDirectory> _session_dir;

        void hookup_io ();
        void graph_reordered ();

        std::string _current_snapshot_name;

        XMLTree*         state_tree;
        bool             state_was_pending;
        StateOfTheState _state_of_the_state;

        friend class    StateProtector;
        gint            _suspend_save; /* atomic */
        volatile bool   _save_queued;
        Glib::Threads::Mutex save_state_lock;

        int      load_options (const XMLNode&);
        int      load_state (std::string snapshot_name);

        framepos_t _last_roll_location;
        framepos_t _last_roll_or_reversal_location;
        framepos_t _last_record_location;

        bool              pending_locate_roll;
        framepos_t        pending_locate_frame;
        bool              pending_locate_flush;
        bool              pending_abort;
        bool              pending_auto_loop;

        Butler* _butler;

        static const PostTransportWork ProcessCannotProceedMask =
                PostTransportWork (
                        PostTransportInputChange|
                        PostTransportSpeed|
                        PostTransportReverse|
                        PostTransportCurveRealloc|
                        PostTransportAudition|
                        PostTransportLocate|
                        PostTransportStop|
                        PostTransportClearSubstate);

        gint _post_transport_work; /* accessed only atomic ops */
        PostTransportWork post_transport_work() const        { return (PostTransportWork) g_atomic_int_get (const_cast<gint*>(&_post_transport_work)); }
        void set_post_transport_work (PostTransportWork ptw) { g_atomic_int_set (&_post_transport_work, (gint) ptw); }
        void add_post_transport_work (PostTransportWork ptw);

        void schedule_playback_buffering_adjustment ();
        void schedule_capture_buffering_adjustment ();

        uint32_t    cumulative_rf_motion;
        uint32_t    rf_scale;

        void set_rf_speed (float speed);
        void reset_rf_scale (framecnt_t frames_moved);

        Locations*       _locations;
        void location_added (Location*);
        void location_removed (Location*);
        void locations_changed ();
        void _locations_changed (const Locations::LocationList&);

        void update_skips (Location*, bool consolidate);
        void update_marks (Location* loc);
        void update_loop (Location* loc);
        void consolidate_skips (Location*);
        void sync_locations_to_skips ();
        void _sync_locations_to_skips ();
    
        PBD::ScopedConnectionList skip_update_connections;
        bool _ignore_skips_updates;

        PBD::ScopedConnectionList punch_connections;
        void             auto_punch_start_changed (Location *);
        void             auto_punch_end_changed (Location *);
        void             auto_punch_changed (Location *);

        PBD::ScopedConnectionList loop_connections;
        void             auto_loop_changed (Location *);
        void             auto_loop_declick_range (Location *, framepos_t &, framepos_t &);

        int  ensure_engine (uint32_t desired_sample_rate);
        void pre_engine_init (std::string path);
        int  post_engine_init ();
        int  immediately_post_engine ();
        void remove_empty_sounds ();

        void setup_midi_control ();
        int  midi_read (MIDI::Port *);

        void enable_record ();

        void increment_transport_position (framecnt_t val) {
                if (max_framepos - val < _transport_frame) {
                        _transport_frame = max_framepos;
                } else {
                        _transport_frame += val;
                }
        }

        void decrement_transport_position (framecnt_t val) {
                if (val < _transport_frame) {
                        _transport_frame -= val;
                } else {
                        _transport_frame = 0;
                }
        }

        void post_transport_motion ();
        static void *session_loader_thread (void *arg);

        void *do_work();

        /* Signal Forwarding */
        void emit_route_signals ();
        void emit_thread_run ();
        static void *emit_thread (void *);
        void emit_thread_start ();
        void emit_thread_terminate ();

        pthread_t       _rt_emit_thread;
        bool            _rt_thread_active;

        pthread_mutex_t _rt_emit_mutex;
        pthread_cond_t  _rt_emit_cond;
        bool            _rt_emit_pending;


        /* SessionEventManager interface */

        void process_event (SessionEvent*);
        void set_next_event ();
        void cleanup_event (SessionEvent*,int);

        /* MIDI Machine Control */

        void spp_start ();
        void spp_continue ();
        void spp_stop ();

        void mmc_deferred_play (MIDI::MachineControl &);
        void mmc_stop (MIDI::MachineControl &);
        void mmc_step (MIDI::MachineControl &, int);
        void mmc_pause (MIDI::MachineControl &);
        void mmc_record_pause (MIDI::MachineControl &);
        void mmc_record_strobe (MIDI::MachineControl &);
        void mmc_record_exit (MIDI::MachineControl &);
        void mmc_track_record_status (MIDI::MachineControl &, uint32_t track, bool enabled);
        void mmc_fast_forward (MIDI::MachineControl &);
        void mmc_rewind (MIDI::MachineControl &);
        void mmc_locate (MIDI::MachineControl &, const MIDI::byte *);
        void mmc_shuttle (MIDI::MachineControl &mmc, float speed, bool forw);
        void mmc_record_enable (MIDI::MachineControl &mmc, size_t track, bool enabled);

        struct timeval last_mmc_step;
        double step_speed;

        typedef boost::function<bool()> MidiTimeoutCallback;
        typedef std::list<MidiTimeoutCallback> MidiTimeoutList;

        MidiTimeoutList midi_timeouts;
        bool mmc_step_timeout ();
        void send_immediate_mmc (MIDI::MachineControlCommand);

        MIDI::byte mtc_msg[16];
        MIDI::byte mtc_timecode_bits;   /* encoding of SMTPE type for MTC */
        MIDI::byte midi_msg[16];
        double outbound_mtc_timecode_frame;
        Timecode::Time transmitting_timecode_time;
        int next_quarter_frame_to_send;

        double _frames_per_timecode_frame; /* has to be floating point because of drop frame */
        framecnt_t _frames_per_hour;
        framecnt_t _timecode_frames_per_hour;

        /* cache the most-recently requested time conversions. This helps when we
         * have multiple clocks showing the same time (e.g. the transport frame) */
        bool last_timecode_valid;
        framepos_t last_timecode_when;
        Timecode::Time last_timecode;

        bool _send_timecode_update; 

        int send_midi_time_code_for_cycle (framepos_t, framepos_t, pframes_t nframes);

        LTCEncoder*       ltc_encoder;
        ltcsnd_sample_t*  ltc_enc_buf;

        Timecode::TimecodeFormat ltc_enc_tcformat;
        int32_t           ltc_buf_off;
        int32_t           ltc_buf_len;

        double            ltc_speed;
        int32_t           ltc_enc_byte;
        framepos_t        ltc_enc_pos;
        double            ltc_enc_cnt;
        framepos_t        ltc_enc_off;
        bool              restarting;
        framepos_t        ltc_prev_cycle;

        framepos_t        ltc_timecode_offset;
        bool              ltc_timecode_negative_offset;

        LatencyRange      ltc_out_latency;

        void ltc_tx_initialize();
        void ltc_tx_cleanup();
        void ltc_tx_reset();
        void ltc_tx_resync_latency();
        void ltc_tx_recalculate_position();
        void ltc_tx_parse_offset();
        void ltc_tx_send_time_code_for_cycle (framepos_t, framepos_t, double, double, pframes_t nframes);

        void reset_record_status ();

        int no_roll (pframes_t nframes);
        int fail_roll (pframes_t nframes);

        bool non_realtime_work_pending() const { return static_cast<bool>(post_transport_work()); }
        bool process_can_proceed() const { return !(post_transport_work() & ProcessCannotProceedMask); }

        MidiControlUI* midi_control_ui;

        int           start_midi_thread ();

        void set_play_loop (bool yn, double speed);
        void unset_play_loop ();
        void overwrite_some_buffers (Track *);
        void flush_all_inserts ();
        int  micro_locate (framecnt_t distance);
        void locate (framepos_t, bool with_roll, bool with_flush, bool with_loop=false, bool force=false, bool with_mmc=true);
        void start_locate (framepos_t, bool with_roll, bool with_flush, bool with_loop=false, bool force=false);
        void force_locate (framepos_t frame, bool with_roll = false);
        void set_track_speed (Track *, double speed);
        void set_transport_speed (double speed, framepos_t destination_frame, bool abort = false, bool clear_state = false, bool as_default = false);
        void stop_transport (bool abort = false, bool clear_state = false);
        void start_transport ();
        void realtime_stop (bool abort, bool clear_state);
        void realtime_locate ();
        void non_realtime_start_scrub ();
        void non_realtime_set_speed ();
        void non_realtime_locate ();
        void non_realtime_stop (bool abort, int entry_request_count, bool& finished);
        void non_realtime_overwrite (int entry_request_count, bool& finished);
        void post_transport ();
        void engine_halted ();
        void xrun_recovery ();
        void set_track_loop (bool);
        
        /* These are synchronous and so can only be called from within the process
         * cycle
         */

        int  send_full_time_code (framepos_t, pframes_t nframes);
        void send_song_position_pointer (framepos_t);

        TempoMap    *_tempo_map;
        void          tempo_map_changed (const PBD::PropertyChange&);

        /* edit/mix groups */

        int load_route_groups (const XMLNode&, int);

        std::list<RouteGroup *> _route_groups;
        RouteGroup*             _all_route_group;

        /* routes stuff */

        boost::shared_ptr<Graph> _process_graph;

        SerializedRCUManager<RouteList>  routes;

        void add_routes (RouteList&, bool input_auto_connect, bool output_auto_connect, bool save);
        void add_routes_inner (RouteList&, bool input_auto_connect, bool output_auto_connect);
        bool _adding_routes_in_progress;
        uint32_t destructive_index;

        boost::shared_ptr<Route> XMLRouteFactory (const XMLNode&, int);
        boost::shared_ptr<Route> XMLRouteFactory_2X (const XMLNode&, int);

        void route_processors_changed (RouteProcessorChange);

        bool find_route_name (std::string const &, uint32_t& id, char* name, size_t name_len, bool);
        void count_existing_track_channels (ChanCount& in, ChanCount& out);
        void auto_connect_route (boost::shared_ptr<Route> route, ChanCount& existing_inputs, ChanCount& existing_outputs,
                                 bool with_lock, bool connect_inputs = true,
                                 ChanCount input_start = ChanCount (), ChanCount output_start = ChanCount ());
        void midi_output_change_handler (IOChange change, void* /*src*/, boost::weak_ptr<Route> midi_track);

        /* track numbering */

        void reassign_track_numbers ();
        uint32_t _track_number_decimals;

        /* mixer stuff */

        bool solo_update_disabled;

        void route_listen_changed (void *src, boost::weak_ptr<Route>);
        void route_mute_changed (void *src);
        void route_solo_changed (bool self_solo_change, void *src, boost::weak_ptr<Route>);
        void route_solo_isolated_changed (void *src, boost::weak_ptr<Route>);
        void update_route_solo_state (boost::shared_ptr<RouteList> r = boost::shared_ptr<RouteList>());

        void listen_position_changed ();
        void solo_control_mode_changed ();

        /* REGION MANAGEMENT */

        mutable Glib::Threads::Mutex region_lock;

        int load_regions (const XMLNode& node);
        int load_compounds (const XMLNode& node);

        void route_added_to_route_group (RouteGroup *, boost::weak_ptr<Route>);
        void route_removed_from_route_group (RouteGroup *, boost::weak_ptr<Route>);
        void route_group_property_changed (RouteGroup *);

        /* SOURCES */

        mutable Glib::Threads::Mutex source_lock;

  public:
        typedef std::map<PBD::ID,boost::shared_ptr<Source> > SourceMap;

  private:
        void reset_write_sources (bool mark_write_complete, bool force = false);
        SourceMap sources;


  private:
        int load_sources (const XMLNode& node);
        XMLNode& get_sources_as_xml ();

        boost::shared_ptr<Source> XMLSourceFactory (const XMLNode&);

        /* PLAYLISTS */

        void remove_playlist (boost::weak_ptr<Playlist>);
        void track_playlist_changed (boost::weak_ptr<Track>);
        void playlist_region_added (boost::weak_ptr<Region>);
        void playlist_ranges_moved (std::list<Evoral::RangeMove<framepos_t> > const &);
        void playlist_regions_extended (std::list<Evoral::Range<framepos_t> > const &);

        /* CURVES and AUTOMATION LISTS */
        std::map<PBD::ID, AutomationList*> automation_lists;

        /* DEFAULT FADE CURVES */

        float default_fade_steepness;
        float default_fade_msecs;

        /* AUDITIONING */

        boost::shared_ptr<Auditioner> auditioner;
        void set_audition (boost::shared_ptr<Region>);
        void non_realtime_set_audition ();
        boost::shared_ptr<Region> pending_audition_region;

        /* EXPORT */

        /* FLATTEN */

        int flatten_one_track (AudioTrack&, framepos_t start, framecnt_t cnt);

        /* INSERT AND SEND MANAGEMENT */

        boost::dynamic_bitset<uint32_t> send_bitset;
        boost::dynamic_bitset<uint32_t> aux_send_bitset;
        boost::dynamic_bitset<uint32_t> return_bitset;
        boost::dynamic_bitset<uint32_t> insert_bitset;

        /* S/W RAID */

        struct space_and_path {
                uint32_t blocks;     
                bool blocks_unknown; 
                std::string path;

                space_and_path ()
                        : blocks (0)
                        , blocks_unknown (true)
                {}
        };

        struct space_and_path_ascending_cmp {
                bool operator() (space_and_path a, space_and_path b) {
                        if (a.blocks_unknown != b.blocks_unknown) {
                                return !a.blocks_unknown;
                        }
                        return a.blocks > b.blocks;
                }
        };

        void setup_raid_path (std::string path);

        std::vector<space_and_path> session_dirs;
        std::vector<space_and_path>::iterator last_rr_session_dir;
        uint32_t _total_free_4k_blocks;
        bool _total_free_4k_blocks_uncertain;
        Glib::Threads::Mutex space_lock;

        bool no_questions_about_missing_files;

        std::string get_best_session_directory_for_new_audio ();

        mutable gint _playback_load;
        mutable gint _capture_load;

        /* I/O bundles */

        SerializedRCUManager<BundleList> _bundles;
        XMLNode* _bundle_xml_node;
        int load_bundles (XMLNode const &);

        UndoHistory      _history;
        UndoTransaction* _current_trans;
        std::list<GQuark> _current_trans_quarks;

        int  backend_sync_callback (TransportState, framepos_t);

        void process_rtop (SessionEvent*);

        void  update_latency (bool playback);

        XMLNode& state(bool);

        /* click track */
        typedef std::list<Click*> Clicks;
        Clicks                  clicks;
        bool                   _clicking;
        boost::shared_ptr<IO>  _click_io;
        boost::shared_ptr<Amp> _click_gain;
        Sample*                 click_data;
        Sample*                 click_emphasis_data;
        framecnt_t              click_length;
        framecnt_t              click_emphasis_length;
        mutable Glib::Threads::RWLock    click_lock;

        static const Sample     default_click[];
        static const framecnt_t default_click_length;
        static const Sample     default_click_emphasis[];
        static const framecnt_t default_click_emphasis_length;

        Click *get_click();
        framepos_t _clicks_cleared;
        void   setup_click_sounds (int which);
        void   setup_click_sounds (Sample**, Sample const *, framecnt_t*, framecnt_t, std::string const &);
        void   clear_clicks ();
        void   click (framepos_t start, framecnt_t nframes);

        std::vector<Route*> master_outs;

        /* range playback */

        std::list<AudioRange> current_audio_range;
        bool _play_range;
        void set_play_range (std::list<AudioRange>&, bool leave_rolling);
        void unset_play_range ();

        /* main outs */
        uint32_t main_outs;

        boost::shared_ptr<Route> _master_out;
        boost::shared_ptr<Route> _monitor_out;

        void auto_connect_master_bus ();

        /* Windows VST support */

        long _windows_vst_callback (
                WindowsVSTPlugin*,
                long opcode,
                long index,
                long value,
                void* ptr,
                float opt
                );

        int find_all_sources (std::string path, std::set<std::string>& result);
        int find_all_sources_across_snapshots (std::set<std::string>& result, bool exclude_this_snapshot);

        typedef std::set<boost::shared_ptr<PBD::Controllable> > Controllables;
        Glib::Threads::Mutex controllables_lock;
        Controllables controllables;

        boost::shared_ptr<PBD::Controllable> _solo_cut_control;

        void reset_native_file_format();
        bool first_file_data_format_reset;
        bool first_file_header_format_reset;

        void config_changed (std::string, bool);

        XMLNode& get_control_protocol_state ();

        void set_history_depth (uint32_t depth);

        static bool _disable_all_loaded_plugins;

        mutable bool have_looped; 

        void update_have_rec_enabled_track ();
        gint _have_rec_enabled_track;

        static int ask_about_playlist_deletion (boost::shared_ptr<Playlist>);

        /* realtime "apply to set of routes" operations */
        template<typename T> SessionEvent*
                get_rt_event (boost::shared_ptr<RouteList> rl, T targ, SessionEvent::RTeventCallback after, bool group_override,
                              void (Session::*method) (boost::shared_ptr<RouteList>, T, bool)) {
                SessionEvent* ev = new SessionEvent (SessionEvent::RealTimeOperation, SessionEvent::Add, SessionEvent::Immediate, 0, 0.0);
                ev->rt_slot = boost::bind (method, this, rl, targ, group_override);
                ev->rt_return = after;
                ev->event_loop = PBD::EventLoop::get_event_loop_for_thread ();
                
                return ev;
        }

        void rt_cancel_solo_after_disconnect (boost::shared_ptr<RouteList>, bool upstream, bool /* ignored*/ );
        void rt_set_solo (boost::shared_ptr<RouteList>, bool yn, bool group_override);
        void rt_set_just_one_solo (boost::shared_ptr<RouteList>, bool yn, bool /* ignored*/ );
        void rt_set_mute (boost::shared_ptr<RouteList>, bool yn, bool group_override);
        void rt_set_listen (boost::shared_ptr<RouteList>, bool yn, bool group_override);
        void rt_set_solo_isolated (boost::shared_ptr<RouteList>, bool yn, bool group_override);
        void rt_set_record_enabled (boost::shared_ptr<RouteList>, bool yn, bool group_override);
        void rt_set_monitoring (boost::shared_ptr<RouteList>, MonitorChoice, bool group_override);

        std::list<boost::shared_ptr<Diskstream> > _diskstreams_2X;

        void add_session_range_location (framepos_t, framepos_t);

        void setup_midi_machine_control ();

        void step_edit_status_change (bool);
        uint32_t _step_editors;

        mutable gint _suspend_timecode_transmission;

        void update_locations_after_tempo_map_change (const Locations::LocationList &);

        void start_time_changed (framepos_t);
        void end_time_changed (framepos_t);

        void set_track_monitor_input_status (bool);
        framepos_t compute_stop_limit () const;

        boost::shared_ptr<Speakers> _speakers;
        void load_nested_sources (const XMLNode& node);

        GraphEdges _current_route_graph;

        uint32_t next_control_id () const;
        int32_t _order_hint;
        bool ignore_route_processor_changes;

        MidiClockTicker* midi_clock;

        boost::shared_ptr<IO>   _ltc_input;
        boost::shared_ptr<IO>   _ltc_output;

        void reconnect_ltc_input ();
        void reconnect_ltc_output ();

        /* Scene Changing */
        SceneChanger* _scene_changer;
        
        /* persistent, non-track related MIDI ports */
        MidiPortManager* _midi_ports;
        MIDI::MachineControl* _mmc;
        
        void setup_ltc ();
        void setup_click ();
        void setup_click_state (const XMLNode*);
        void setup_bundles ();
        
        void save_as_bring_callback (uint32_t, uint32_t, std::string);

        static int get_session_info_from_path (XMLTree& state_tree, const std::string& xmlpath);
};


} // namespace ARDOUR

#endif /* __ardour_session_h__ */