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)
13 #include <boost/mpl/vector/vector50.hpp>
14 #include <boost/msm/back/state_machine.hpp>
15 #include <boost/msm/front/state_machine_def.hpp>
16 #include <boost/msm/back/tools.hpp>
18 namespace msm
= boost::msm
;
19 namespace mpl
= boost::mpl
;
21 namespace // Concrete FSM implementation
30 // event which every other event can convert to
33 template <class Event
>
34 AllSongsPlayed(Event
const&){}
36 struct PreviousSong
{};
37 struct error_found
{};
40 // Flags. Allow information about a property of the current state
42 struct FirstSongPlaying
{};
44 // A "complicated" event type that carries some data.
52 cd_detected(DiskTypeEnum diskType
): disc_type(diskType
) {}
53 DiskTypeEnum disc_type
;
56 // Concrete FSM implementation
57 struct player_
: public msm::front::state_machine_def
<player_
>
59 // The list of FSM states
60 struct Empty
: public msm::front::state
<>
62 typedef mpl::vector
<play
> deferred_events
;
63 // every (optional) entry/exit methods get the event packed as boost::any. Not useful very often.
64 template <class Event
,class FSM
>
65 void on_entry(Event
const&,FSM
& ) {std::cout
<< "entering: Empty" << std::endl
;}
66 template <class Event
,class FSM
>
67 void on_exit(Event
const&,FSM
& ) {std::cout
<< "leaving: Empty" << std::endl
;}
69 struct Open
: public msm::front::state
<>
71 typedef mpl::vector1
<CDLoaded
> flag_list
;
72 typedef mpl::vector
<play
> deferred_events
;
73 template <class Event
,class FSM
>
74 void on_entry(Event
const&,FSM
& ) {std::cout
<< "entering: Open" << std::endl
;}
75 template <class Event
,class FSM
>
76 void on_exit(Event
const&,FSM
& ) {std::cout
<< "leaving: Open" << std::endl
;}
78 // a state needing a pointer to the containing state machine
79 // and using for this the non-default policy
80 // if policy used, set_sm_ptr is needed
81 struct Stopped
: public msm::front::state
<default_base_state
,msm::front::sm_ptr
>
83 // when stopped, the CD is loaded
84 typedef mpl::vector1
<CDLoaded
> flag_list
;
85 template <class Event
,class FSM
>
86 void on_entry(Event
const&,FSM
& ) {std::cout
<< "entering: Stopped" << std::endl
;}
87 template <class Event
,class FSM
>
88 void on_exit(Event
const&,FSM
& ) {std::cout
<< "leaving: Stopped" << std::endl
;}
89 void set_sm_ptr(player_
* pl
){m_player
=pl
;}
92 // the player state machine contains a state which is himself a state machine
93 // it demonstrates Shallow History: if the state gets activated with end_pause
94 // then it will remember the last active state and reactivate it
95 // also possible: AlwaysHistory, the last active state will always be reactivated
96 // or NoHistory, always restart from the initial state
97 struct Playing_
: public msm::front::state_machine_def
<Playing_
>
99 // when playing, the CD is loaded and we are in either pause or playing (duh)
100 typedef mpl::vector
<CDLoaded
> flag_list
;
101 template <class Event
,class FSM
>
102 void on_entry(Event
const&,FSM
& ) {std::cout
<< "entering: Playing" << std::endl
;}
103 template <class Event
,class FSM
>
104 void on_exit(Event
const&,FSM
& ) {std::cout
<< "leaving: Playing" << std::endl
;}
106 // The list of FSM states
107 struct Song1
: public msm::front::state
<>
109 typedef mpl::vector1
<FirstSongPlaying
> flag_list
;
110 template <class Event
,class FSM
>
111 void on_entry(Event
const&,FSM
& ) {std::cout
<< "starting: First song" << std::endl
;}
112 template <class Event
,class FSM
>
113 void on_exit(Event
const&,FSM
& ) {std::cout
<< "finishing: First Song" << std::endl
;}
115 struct Song2
: public msm::front::state
<>
117 template <class Event
,class FSM
>
118 void on_entry(Event
const&,FSM
& ) {std::cout
<< "starting: Second song" << std::endl
;}
119 template <class Event
,class FSM
>
120 void on_exit(Event
const&,FSM
& ) {std::cout
<< "finishing: Second Song" << std::endl
;}
122 struct Song3
: public msm::front::state
<>
124 template <class Event
,class FSM
>
125 void on_entry(Event
const&,FSM
& ) {std::cout
<< "starting: Third song" << std::endl
;}
126 template <class Event
,class FSM
>
127 void on_exit(Event
const&,FSM
& ) {std::cout
<< "finishing: Third Song" << std::endl
;}
129 struct CDFinished
: public msm::front::exit_pseudo_state
<AllSongsPlayed
>
131 template <class Event
,class FSM
>
132 void on_entry(Event
const&,FSM
& ) {std::cout
<< "entering: Playing::CDFinished" << std::endl
;}
133 template <class Event
,class FSM
>
134 void on_exit(Event
const&,FSM
& ) {std::cout
<< "leaving: Playing::CDFinished" << std::endl
;}
136 // the initial state. Must be defined
137 typedef Song1 initial_state
;
138 // transition actions
139 void start_next_song(NextSong
const&) { std::cout
<< "Playing::start_next_song\n"; }
140 void start_prev_song(PreviousSong
const&) { std::cout
<< "Playing::start_prev_song\n"; }
141 void all_songs_played(NextSong
const&) { std::cout
<< "Playing::all_songs_played\n"; }
144 typedef Playing_ pl
; // makes transition table cleaner
145 // Transition table for Playing
146 struct transition_table
: mpl::vector
<
147 // Start Event Next Action Guard
148 // +---------+---------------+------------+---------------------+----------------------+
149 a_row
< Song1
, NextSong
, Song2
, &pl::start_next_song
>,
150 a_row
< Song2
, PreviousSong
, Song1
, &pl::start_prev_song
>,
151 a_row
< Song2
, NextSong
, Song3
, &pl::start_next_song
>,
152 a_row
< Song3
, PreviousSong
, Song2
, &pl::start_prev_song
>,
153 a_row
< Song3
, NextSong
, CDFinished
, &pl::all_songs_played
>
154 // +---------+---------------+---------+---------------------+----------------------+
156 // Replaces the default no-transition response.
157 template <class FSM
,class Event
>
158 void no_transition(Event
const& e
, FSM
&,int state
)
160 std::cout
<< "no transition from state " << state
161 << " on event " << typeid(e
).name() << std::endl
;
164 typedef msm::back::state_machine
<Playing_
,msm::back::ShallowHistory
<mpl::vector
<end_pause
> > > Playing
;
166 // the player state machine contains a state which is himself a state machine (2 of them, Playing and Paused)
167 struct Paused
: public msm::front::state
<>
169 typedef mpl::vector
<CDLoaded
> flag_list
;
170 template <class Event
,class FSM
>
171 void on_entry(Event
const&,FSM
& ) {std::cout
<< "entering: Paused" << std::endl
;}
172 template <class Event
,class FSM
>
173 void on_exit(Event
const&,FSM
& ) {std::cout
<< "leaving: Paused" << std::endl
;}
176 struct AllOk
: public msm::front::state
<>
178 template <class Event
,class FSM
>
179 void on_entry(Event
const&,FSM
& ) {std::cout
<< "starting: AllOk" << std::endl
;}
180 template <class Event
,class FSM
>
181 void on_exit(Event
const&,FSM
& ) {std::cout
<< "finishing: AllOk" << std::endl
;}
183 struct ErrorMode
: //public msm::front::terminate_state<>
184 public msm::front::interrupt_state
<end_error
>
186 template <class Event
,class FSM
>
187 void on_entry(Event
const&,FSM
& ) {std::cout
<< "starting: ErrorMode" << std::endl
;}
188 template <class Event
,class FSM
>
189 void on_exit(Event
const&,FSM
& ) {std::cout
<< "finishing: ErrorMode" << std::endl
;}
192 // the initial state of the player SM. Must be defined
193 typedef mpl::vector
<Empty
,AllOk
> initial_state
;
195 // transition actions
196 void start_playback(play
const&) { std::cout
<< "player::start_playback\n"; }
197 void open_drawer(open_close
const&) { std::cout
<< "player::open_drawer\n"; }
198 void close_drawer(open_close
const&) { std::cout
<< "player::close_drawer\n"; }
199 void store_cd_info(cd_detected
const&)
201 std::cout
<< "player::store_cd_info\n";
202 // generate another event to test the queue
203 //cd.m_player.process_event(play());
205 void stop_playback(stop
const&) { std::cout
<< "player::stop_playback\n"; }
206 void end_playback (AllSongsPlayed
const&) { std::cout
<< "player::end_playback\n"; }
207 void pause_playback(pause
const&) { std::cout
<< "player::pause_playback\n"; }
208 void resume_playback(end_pause
const&) { std::cout
<< "player::resume_playback\n"; }
209 void stop_and_open(open_close
const&) { std::cout
<< "player::stop_and_open\n"; }
210 void stopped_again(stop
const&){std::cout
<< "player::stopped_again\n";}
211 void report_error(error_found
const&) {std::cout
<< "player::report_error\n";}
212 void report_end_error(end_error
const&) {std::cout
<< "player::report_end_error\n";}
214 bool good_disk_format(cd_detected
const& evt
)
216 // to test a guard condition, let's say we understand only CDs, not DVD
217 if (evt
.disc_type
!= DISK_CD
)
219 std::cout
<< "wrong disk, sorry" << std::endl
;
225 typedef player_ p
; // makes transition table cleaner
227 // Transition table for player
228 struct transition_table
: mpl::vector
<
229 // Start Event Next Action Guard
230 // +-------------+---------------+---------+---------------------+----------------------+
231 a_row
< Stopped
, play
, Playing
, &p::start_playback
>,
232 a_row
< Stopped
, open_close
, Open
, &p::open_drawer
>,
233 a_row
< Stopped
, stop
, Stopped
, &p::stopped_again
>,
234 // +-------------+---------------+---------+---------------------+----------------------+
235 a_row
< Open
, open_close
, Empty
, &p::close_drawer
>,
236 // +-------------+---------------+---------+---------------------+----------------------+
237 a_row
< Empty
, open_close
, Open
, &p::open_drawer
>,
238 row
< Empty
, cd_detected
, Stopped
, &p::store_cd_info
,&p::good_disk_format
>,
239 // +-------------+---------------+---------+---------------------+----------------------+
240 a_row
< Playing
, stop
, Stopped
, &p::stop_playback
>,
241 a_row
< Playing
, pause
, Paused
, &p::pause_playback
>,
242 a_row
< Playing
, open_close
, Open
, &p::stop_and_open
>,
243 a_row
< Playing::exit_pt
<
244 Playing_::CDFinished
> , AllSongsPlayed
, Stopped
, &p::end_playback
>,
245 // +-------------+---------------+---------+---------------------+----------------------+
246 a_row
< Paused
, end_pause
, Playing
, &p::resume_playback
>,
247 a_row
< Paused
, stop
, Stopped
, &p::stop_playback
>,
248 a_row
< Paused
, open_close
, Open
, &p::stop_and_open
>,
249 // +-------------+---------------+---------+---------------------+----------------------+
250 a_row
< AllOk
, error_found
,ErrorMode
, &p::report_error
>,
251 a_row
< ErrorMode
,end_error
,AllOk
, &p::report_end_error
>
252 // +-------------+---------------+---------+---------------------+----------------------+
256 // Replaces the default no-transition response.
257 template <class FSM
,class Event
>
258 void no_transition(Event
const& e
, FSM
&,int state
)
260 std::cout
<< "no transition from state " << state
261 << " on event " << typeid(e
).name() << std::endl
;
264 typedef msm::back::state_machine
<player_
> player
;
267 // Testing utilities.
270 void pstate(player
const& p
)
272 typedef player::stt Stt
;
273 typedef msm::back::generate_state_set
<Stt
>::type all_states
;
274 static char const* state_names
[mpl::size
<all_states
>::value
];
275 // fill the names of the states defined in the state machine
276 mpl::for_each
<all_states
,boost::msm::wrap
<mpl::placeholders::_1
> >
277 (msm::back::fill_state_names
<Stt
>(state_names
));
279 for (unsigned int i
=0;i
<player::nr_regions::value
;++i
)
281 std::cout
<< " -> " << state_names
[p
.current_state()[i
]] << std::endl
;
288 // needed to start the highest-level SM. This will call on_entry and mark the start of the SM
290 std::cout
<< "CDLoaded active:" << std::boolalpha
<< p
.is_flag_active
<CDLoaded
>() << std::endl
; //=> false (no CD yet)
292 // test deferred event
293 // deferred in Empty and Open, will be handled only after event cd_detected
294 std::cout
<< "play is not handled in the current state but is marked as delayed" << std::endl
;
295 p
.process_event(play()); pstate(p
);
296 std::cout
<< "cd_detected will cause play to be handled also" << std::endl
;
297 // will be rejected, wrong disk type
298 p
.process_event(cd_detected(DISK_DVD
)); pstate(p
);
299 // will be accepted, wrong disk type
300 p
.process_event(cd_detected(DISK_CD
)); pstate(p
);
302 std::cout
<< "FirstSong active:" << std::boolalpha
<< p
.is_flag_active
<FirstSongPlaying
>() << std::endl
; //=> true
303 p
.process_event(NextSong());pstate(p
);
304 // We are now in second song, Flag inactive
305 std::cout
<< "FirstSong active:" << std::boolalpha
<< p
.is_flag_active
<FirstSongPlaying
>() << std::endl
;//=> false
306 p
.process_event(NextSong());pstate(p
);
308 p
.process_event(PreviousSong());pstate(p
);
310 p
.process_event(pause()); pstate(p
);
311 // go back to Playing
312 // but end_pause is an event activating the History
313 // => keep the last active State (SecondSong)
314 p
.process_event(end_pause()); pstate(p
);
315 // force an exit by listening all the songs
316 p
.process_event(NextSong());
317 p
.process_event(NextSong());pstate(p
);
319 std::cout
<< "CDLoaded active:" << std::boolalpha
<< p
.is_flag_active
<CDLoaded
>() << std::endl
;//=> true
320 std::cout
<< "FirstSong active:" << std::boolalpha
<< p
.is_flag_active
<FirstSongPlaying
>() << std::endl
;//=> false
322 // go back to Playing
323 // but play is not leading to Shallow History => do not remember the last active State (SecondSong)
324 // and activate again FirstSong and LightOn
325 p
.process_event(play()); pstate(p
);
326 p
.process_event(error_found()); pstate(p
);
328 // try generating more events
329 std::cout
<< "Trying to generate another event" << std::endl
; // will not work, fsm is terminated or interrupted
330 p
.process_event(NextSong());pstate(p
);
332 std::cout
<< "Trying to end the error" << std::endl
; // will work only if ErrorMode is interrupt state
333 p
.process_event(end_error());pstate(p
);
334 std::cout
<< "Trying to generate another event" << std::endl
; // will work only if ErrorMode is interrupt state
335 p
.process_event(NextSong());pstate(p
);
337 // the states and events of the higher level FSM (player)
338 typedef player::stt Stt
;
339 typedef msm::back::generate_state_set
<Stt
>::type simple_states
;
341 std::cout
<< "the state list:" << std::endl
;
342 mpl::for_each
<simple_states
,boost::msm::wrap
<mpl::placeholders::_1
> >(msm::back::display_type ());
344 std::cout
<< "the event list:" << std::endl
;
345 typedef msm::back::generate_event_set
<Stt
>::type event_list
;
346 mpl::for_each
<event_list
,boost::msm::wrap
<mpl::placeholders::_1
> >(msm::back::display_type ());
347 std::cout
<< std::endl
;
349 // the states and events recursively searched
350 typedef msm::back::recursive_get_transition_table
<player
>::type recursive_stt
;
352 std::cout
<< "the state list (including sub-SMs):" << std::endl
;
354 typedef msm::back::generate_state_set
<recursive_stt
>::type all_states
;
355 mpl::for_each
<all_states
,boost::msm::wrap
<mpl::placeholders::_1
> >(msm::back::display_type ());
357 std::cout
<< "the event list (including sub-SMs):" << std::endl
;
358 typedef msm::back::generate_event_set
<recursive_stt
>::type all_events
;
359 mpl::for_each
<all_events
,boost::msm::wrap
<mpl::placeholders::_1
> >(msm::back::display_type ());