1 #ifndef _ardour_transport_fsm_h_ 2 #define _ardour_transport_fsm_h_ 3 4 #include <list> 5 #include <queue> 6 7 #include <boost/intrusive/list.hpp> 8 #include <boost/optional.hpp> 9 10 #include <string> 11 #include <utility> 12 #include <iostream> 13 14 #include "pbd/demangle.h" 15 16 #include "ardour/debug.h" 17 #include "ardour/types.h" 18 19 namespace ARDOUR 20 { 21 22 class TransportAPI; 23 24 struct TransportFSM 25 { 26 /* All code related to this object is expected to be run synchronously 27 * and single-threaded from the process callback. It can be re-entrant 28 * if handling one transport state change queues another state change, 29 * but that is handled explicitly (see the @param processing member and 30 * its usage). 31 */ 32 33 public: 34 enum EventType { 35 ButlerDone, 36 ButlerRequired, 37 DeclickDone, 38 StartTransport, 39 StopTransport, 40 Locate, 41 LocateDone, 42 SetSpeed, 43 }; 44 45 struct Event : public boost::intrusive::list_base_hook<> { 46 EventType type; 47 /* for stop and speed */ 48 bool abort_capture; 49 bool clear_state; 50 /* for locate */ 51 LocateTransportDisposition ltd; 52 samplepos_t target; 53 bool for_loop_end; 54 bool force; 55 /* for SetSpeed */ 56 double speed; 57 bool as_default; 58 EventTransportFSM::Event59 Event (EventType t) 60 : type (t) 61 , abort_capture (false) 62 , clear_state (false) 63 , ltd (MustStop) 64 , target (0) 65 , for_loop_end (false) 66 , force (false) 67 { 68 assert (t != StopTransport); 69 assert (t != Locate); 70 } EventTransportFSM::Event71 Event (EventType t, bool ab, bool cl) 72 : type (t) 73 , abort_capture (ab) 74 , clear_state (cl) 75 , ltd (MustStop) 76 , target (0) 77 , for_loop_end (false) 78 , force (false) 79 { 80 assert (t == StopTransport); 81 } EventTransportFSM::Event82 Event (EventType t, samplepos_t pos, LocateTransportDisposition l, bool lp, bool f4c) 83 : type (t) 84 , abort_capture (false) 85 , clear_state (false) 86 , ltd (l) 87 , target (pos) 88 , for_loop_end (lp) 89 , force (f4c) 90 { 91 assert (t == Locate); 92 } 93 /* here we drop the event type as the first argument in order 94 disambiguate from the StopTransport case above (compiler can 95 cast double-to-bool and complains. C++11 would allow "= 96 delete" as an alternate fix, but this is fine. 97 */ EventTransportFSM::Event98 Event (double sp, bool ad) 99 : type (SetSpeed) 100 , speed (sp) 101 , as_default (ad) 102 { 103 } 104 105 void* operator new (size_t); 106 void operator delete (void *ptr, size_t /*size*/); 107 108 static void init_pool (); 109 110 private: 111 static Pool* pool; 112 113 }; 114 115 TransportFSM (TransportAPI& tapi); 116 startTransportFSM117 void start () { 118 init (); 119 } 120 stopTransportFSM121 void stop () { 122 /* should we do anything here? this method is modelled on the 123 boost::msm design, but its not clear that we ever need to 124 do anything like this. 125 */ 126 } 127 128 enum MotionState { 129 Stopped, 130 Rolling, 131 DeclickToStop, 132 DeclickToLocate, 133 WaitingForLocate 134 }; 135 136 enum ButlerState { 137 NotWaitingForButler, 138 WaitingForButler 139 }; 140 141 enum DirectionState { 142 Forwards, 143 Backwards, 144 Reversing, 145 }; 146 147 std::string current_state () const; 148 transport_speedTransportFSM149 double transport_speed() const { return _transport_speed; } default_speedTransportFSM150 double default_speed() const { return _default_speed; } 151 152 private: 153 MotionState _motion_state; 154 ButlerState _butler_state; 155 DirectionState _direction_state; 156 double _transport_speed; 157 158 void init(); 159 160 /* transition actions */ 161 162 void schedule_butler_for_transport_work () const; 163 void start_playback (); 164 void stop_playback (Event const &); 165 void start_locate_after_declick (); 166 void locate_for_loop (Event const &); 167 void roll_after_locate () const; 168 void start_locate_while_stopped (Event const &) const; 169 void interrupt_locate (Event const &) const; 170 void start_declick_for_locate (Event const &); 171 bool set_speed (Event const &); 172 173 /* guards */ 174 175 bool should_roll_after_locate () const; should_not_roll_after_locateTransportFSM176 bool should_not_roll_after_locate () const { return !should_roll_after_locate (); } 177 178 public: locatingTransportFSM179 bool locating () const { return _motion_state == WaitingForLocate; } rollingTransportFSM180 bool rolling () const { return _motion_state == Rolling; } stoppedTransportFSM181 bool stopped () const { return _motion_state == Stopped; } stoppingTransportFSM182 bool stopping () const { return _motion_state == DeclickToStop; } waiting_for_butlerTransportFSM183 bool waiting_for_butler() const { return _butler_state == WaitingForButler; } declick_in_progressTransportFSM184 bool declick_in_progress() const { return _motion_state == DeclickToLocate || _motion_state == DeclickToStop; } declicking_for_locateTransportFSM185 bool declicking_for_locate() const { return _motion_state == DeclickToLocate; } forwardsTransportFSM186 bool forwards() const { return _direction_state == Forwards; } backwardsTransportFSM187 bool backwards() const { return _direction_state == Backwards; } reversingTransportFSM188 bool reversing() const { return _direction_state == Reversing; } 189 bool will_roll_fowards() const; 190 191 void enqueue (Event* ev); 192 193 private: 194 195 void transition (MotionState); 196 void transition (ButlerState); 197 void transition (DirectionState); 198 199 void process_events (); 200 bool process_event (Event&, bool was_deferred, bool& deferred); 201 202 mutable Event _last_locate; 203 204 TransportAPI* api; 205 typedef boost::intrusive::list<Event> EventList; 206 EventList queued_events; 207 EventList deferred_events; 208 int processing; 209 mutable boost::optional<bool> current_roll_after_locate_status; 210 mutable double most_recently_requested_speed; 211 mutable double _default_speed; 212 int _reverse_after_declick; 213 214 void defer (Event& ev); 215 void bad_transition (Event const &); 216 void set_roll_after (bool) const; 217 bool compute_should_roll (LocateTransportDisposition) const; 218 int compute_transport_speed () const; 219 bool maybe_reset_speed (); 220 }; 221 222 } /* end namespace ARDOUR */ 223 224 #endif 225