1 // Copyright 2010 Christophe Henry 2 // henry UNDERSCORE christophe AT hotmail DOT com 3 // This is an extended version of the state machine available in the boost::mpl library 4 // Distributed under the same license as the original. 5 // Copyright for the original version: 6 // Copyright 2005 David Abrahams and Aleksey Gurtovoy. Distributed 7 // under the Boost Software License, Version 1.0. (See accompanying 8 // file LICENSE_1_0.txt or copy at 9 // http://www.boost.org/LICENSE_1_0.txt) 10 11 #include <vector> 12 #include <iostream> 13 14 #include <boost/msm/back/state_machine.hpp> 15 #include <boost/msm/front/euml/euml.hpp> 16 17 using namespace std; 18 using namespace boost::msm::front::euml; 19 namespace msm = boost::msm; 20 21 // entry/exit/action/guard logging functors 22 #include "logging_functors.h" 23 24 namespace // Concrete FSM implementation 25 { 26 // events 27 BOOST_MSM_EUML_EVENT(play) 28 BOOST_MSM_EUML_EVENT(end_pause) 29 BOOST_MSM_EUML_EVENT(stop) 30 BOOST_MSM_EUML_EVENT(pause) 31 BOOST_MSM_EUML_EVENT(open_close) 32 BOOST_MSM_EUML_EVENT(next_song) 33 BOOST_MSM_EUML_EVENT(previous_song) 34 BOOST_MSM_EUML_EVENT(end_error) 35 BOOST_MSM_EUML_EVENT(error_found) 36 37 // A "complicated" event type that carries some data. 38 BOOST_MSM_EUML_DECLARE_ATTRIBUTE(std::string,cd_name) 39 BOOST_MSM_EUML_DECLARE_ATTRIBUTE(DiskTypeEnum,cd_type) 40 BOOST_MSM_EUML_ATTRIBUTES((attributes_ << cd_name << cd_type ), cd_detected_attributes) 41 BOOST_MSM_EUML_EVENT_WITH_ATTRIBUTES(cd_detected,cd_detected_attributes) 42 43 // Flags. Allow information about a property of the current state 44 BOOST_MSM_EUML_FLAG(PlayingPaused) 45 BOOST_MSM_EUML_FLAG(CDLoaded) 46 BOOST_MSM_EUML_FLAG(FirstSongPlaying) 47 48 // Concrete FSM implementation 49 // The list of FSM states 50 BOOST_MSM_EUML_STATE(( Empty_Entry, 51 Empty_Exit, 52 attributes_ << no_attributes_, 53 configure_ << no_configure_ 54 ), 55 Empty) 56 57 BOOST_MSM_EUML_STATE(( Open_Entry, 58 Open_Exit, 59 attributes_ << no_attributes_, 60 configure_<< CDLoaded // flag state with CDLoaded 61 ), 62 Open) 63 64 BOOST_MSM_EUML_STATE(( Stopped_Entry, 65 Stopped_Exit, 66 attributes_ << no_attributes_, 67 configure_<< CDLoaded // flag state with CDLoaded 68 ), 69 Stopped) 70 71 // state not defining any entry or exit 72 BOOST_MSM_EUML_STATE(( no_action, 73 no_action, 74 attributes_ << no_attributes_, 75 configure_<< PlayingPaused << CDLoaded // flag state with CDLoaded and PlayingPaused 76 ), 77 Paused) 78 79 BOOST_MSM_EUML_STATE(( AllOk_Entry,AllOk_Exit ),AllOk) 80 81 // a terminate state 82 //BOOST_MSM_EUML_TERMINATE_STATE(( ErrorMode_Entry,ErrorMode_Exit ),ErrorMode) 83 // or as an interrupt state 84 BOOST_MSM_EUML_INTERRUPT_STATE(( end_error,ErrorMode_Entry,ErrorMode_Exit ),ErrorMode) 85 86 // Playing is now a state machine itself. 87 88 // It has 3 substates 89 BOOST_MSM_EUML_STATE(( Song1_Entry, 90 Song1_Exit, 91 attributes_ << no_attributes_, 92 configure_<< FirstSongPlaying ),Song1) 93 94 BOOST_MSM_EUML_STATE(( Song2_Entry,Song2_Exit ),Song2) 95 BOOST_MSM_EUML_STATE(( Song3_Entry,Song3_Exit ),Song3) 96 97 98 // Playing has a transition table 99 BOOST_MSM_EUML_TRANSITION_TABLE(( 100 // +------------------------------------------------------------------------------+ 101 Song2 == Song1 + next_song / start_next_song, 102 Song1 == Song2 + previous_song / start_prev_song, 103 Song3 == Song2 + next_song / start_next_song, 104 Song2 == Song3 + previous_song / start_prev_song 105 // +------------------------------------------------------------------------------+ 106 ),playing_transition_table ) 107 108 BOOST_MSM_EUML_DECLARE_STATE_MACHINE( (playing_transition_table, //STT 109 init_ << Song1, // Init State 110 no_action, // entry 111 no_action, // exit 112 attributes_ << no_attributes_, //attributes 113 configure_<< PlayingPaused << CDLoaded //flags 114 ),Playing_) 115 116 // choice of back-end 117 typedef msm::back::state_machine<Playing_> Playing_type; 118 Playing_type const Playing; 119 120 // guard conditions BOOST_MSM_EUML_ACTION(good_disk_format)121 BOOST_MSM_EUML_ACTION(good_disk_format) 122 { 123 template <class FSM,class EVT,class SourceState,class TargetState> 124 bool operator()(EVT const& evt,FSM&,SourceState& ,TargetState& ) 125 { 126 // to test a guard condition, let's say we understand only CDs, not DVD 127 if (evt.get_attribute(cd_type)!=DISK_CD) 128 { 129 std::cout << "wrong disk, sorry" << std::endl; 130 // just for logging, does not block any transition 131 return true; 132 } 133 std::cout << "good disk" << std::endl; 134 return true; 135 } 136 }; 137 // replaces the old transition table 138 BOOST_MSM_EUML_TRANSITION_TABLE(( 139 Playing == Stopped + play / start_playback , 140 Playing == Paused + end_pause / resume_playback , 141 // +------------------------------------------------------------------------------+ 142 Empty == Open + open_close / close_drawer, 143 // we now defer using the defer_ function. This will need deferred_events as config (see below) 144 Empty + play / defer_ , 145 // +------------------------------------------------------------------------------+ 146 Open == Empty + open_close / open_drawer , 147 Open == Paused + open_close / stop_and_open , 148 Open == Stopped + open_close / open_drawer , 149 Open == Playing + open_close / stop_and_open , 150 // we now defer using the defer_ function. This will need deferred_events as config (see below) 151 Open + play / defer_ , 152 // +------------------------------------------------------------------------------+ 153 Paused == Playing + pause / pause_playback , 154 // +------------------------------------------------------------------------------+ 155 Stopped == Playing + stop / stop_playback , 156 Stopped == Paused + stop / stop_playback , 157 Stopped == Empty + cd_detected [good_disk_format&& 158 (event_(cd_type)==Int_<DISK_CD>())] 159 / (store_cd_info,process_(play)), 160 Stopped == Stopped + stop , 161 ErrorMode == AllOk + error_found / report_error , 162 AllOk == ErrorMode+ end_error / report_end_error 163 // +------------------------------------------------------------------------------+ 164 ),transition_table) 165 166 // create a state machine "on the fly" 167 BOOST_MSM_EUML_DECLARE_STATE_MACHINE(( transition_table, //STT 168 init_ << Empty << AllOk, // Init State 169 no_action, // Entry 170 no_action, // Exit 171 attributes_ << no_attributes_, // Attributes 172 configure_ << deferred_events, // configuration 173 Log_No_Transition // no_transition handler 174 ), 175 player_) //fsm name 176 177 // choice of back-end 178 typedef msm::back::state_machine<player_> player; 179 180 // 181 // Testing utilities. 182 // 183 static char const* const state_names[] = { "Stopped", "Paused", "Open", "Empty", "Playing","AllOk","ErrorMode" }; pstate(player const & p)184 void pstate(player const& p) 185 { 186 // we have now several active states, which we show 187 for (unsigned int i=0;i<player::nr_regions::value;++i) 188 { 189 std::cout << " -> " << state_names[p.current_state()[i]] << std::endl; 190 } 191 } 192 test()193 void test() 194 { 195 player p; 196 // needed to start the highest-level SM. This will call on_entry and mark the start of the SM 197 p.start(); 198 199 // tests some flags 200 std::cout << "CDLoaded active:" << std::boolalpha 201 << p.is_flag_active<BOOST_MSM_EUML_FLAG_NAME(CDLoaded)>() << std::endl; //=> false (no CD yet) 202 // go to Open, call on_exit on Empty, then action, then on_entry on Open 203 p.process_event(open_close); pstate(p); 204 p.process_event(open_close); pstate(p); 205 // will be rejected, wrong disk type 206 p.process_event( 207 cd_detected("louie, louie",DISK_DVD)); pstate(p); 208 p.process_event( 209 cd_detected("louie, louie",DISK_CD)); pstate(p); 210 // no need to call play as the previous event does it in its action method 211 //p.process_event(play); 212 213 // at this point, Play is active 214 p.process_event(pause); pstate(p); 215 std::cout << "PlayingPaused active:" << std::boolalpha 216 << p.is_flag_active<BOOST_MSM_EUML_FLAG_NAME(PlayingPaused)>() << std::endl;//=> true 217 218 // go back to Playing 219 p.process_event(end_pause); pstate(p); 220 p.process_event(pause); pstate(p); 221 p.process_event(stop); pstate(p); 222 std::cout << "PlayingPaused active:" << std::boolalpha 223 << p.is_flag_active<BOOST_MSM_EUML_FLAG_NAME(PlayingPaused)>() << std::endl;//=> false 224 std::cout << "CDLoaded active:" << std::boolalpha 225 << p.is_flag_active<BOOST_MSM_EUML_FLAG_NAME(CDLoaded)>() << std::endl;//=> true 226 // by default, the flags are OR'ed but you can also use AND. Then the flag must be present in 227 // all of the active states 228 std::cout << "CDLoaded active with AND:" << std::boolalpha 229 << p.is_flag_active<BOOST_MSM_EUML_FLAG_NAME(CDLoaded),player::Flag_AND>() << std::endl;//=> false 230 231 // event leading to the same state 232 // no action method called as none is defined in the transition table 233 p.process_event(stop); pstate(p); 234 235 // event leading to a terminal/interrupt state 236 p.process_event(error_found); pstate(p); 237 // try generating more events 238 std::cout << "Trying to generate another event" << std::endl; // will not work, fsm is terminated or interrupted 239 p.process_event(play);pstate(p); 240 std::cout << "Trying to end the error" << std::endl; // will work only if ErrorMode is interrupt state 241 p.process_event(end_error);pstate(p); 242 std::cout << "Trying to generate another event" << std::endl; // will work only if ErrorMode is interrupt state 243 p.process_event(play);pstate(p); 244 } 245 } 246 main()247 int main() 248 { 249 test(); 250 return 0; 251 } 252