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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 <iostream> | |
12 | #include <string> | |
13 | #include "boost/mpl/vector/vector30.hpp" | |
14 | ||
15 | #include <boost/msm/back/state_machine.hpp> | |
16 | #include <boost/msm/front/state_machine_def.hpp> | |
17 | #include <boost/msm/back/tools.hpp> | |
18 | ||
19 | using namespace std; | |
20 | namespace msm = boost::msm; | |
21 | ||
22 | namespace // Concrete FSM implementation | |
23 | { | |
24 | // events | |
25 | struct play {}; | |
26 | struct end_pause {}; | |
27 | struct stop {}; | |
28 | struct pause {}; | |
29 | struct open_close {}; | |
30 | struct NextSong {}; | |
31 | struct PreviousSong {}; | |
32 | struct ThreeSec {}; | |
33 | struct TenSec {}; | |
34 | struct go_sleep {}; | |
35 | struct error_found {}; | |
36 | struct end_error {}; | |
37 | ||
38 | // Flags. Allow information about a property of the current state | |
39 | struct PlayingPaused{}; | |
40 | struct CDLoaded {}; | |
41 | struct FirstSongPlaying {}; | |
42 | ||
43 | // A "complicated" event type that carries some data. | |
44 | struct cd_detected | |
45 | { | |
46 | cd_detected(std::string name) | |
47 | : name(name) | |
48 | {} | |
49 | ||
50 | std::string name; | |
51 | }; | |
52 | // an easy visitor | |
53 | struct SomeVisitor | |
54 | { | |
55 | template <class T> | |
56 | void visit_state(T* astate,int i) | |
57 | { | |
58 | std::cout << "visiting state:" << typeid(*astate).name() | |
59 | << " with data:" << i << std::endl; | |
60 | } | |
61 | }; | |
62 | // overwrite of the base state (not default) | |
63 | struct my_visitable_state | |
64 | { | |
65 | // signature of the accept function | |
66 | typedef msm::back::args<void,SomeVisitor&,int> accept_sig; | |
67 | ||
68 | // we also want polymorphic states | |
69 | virtual ~my_visitable_state() {} | |
70 | // default implementation for states who do not need to be visited | |
71 | void accept(SomeVisitor&,int) const {} | |
72 | }; | |
73 | ||
74 | // Concrete FSM implementation | |
75 | struct player_ : public msm::front::state_machine_def<player_,my_visitable_state> | |
76 | { | |
77 | template <class Event,class FSM> | |
78 | void on_entry(Event const&,FSM& ) {std::cout << "starting: player" << std::endl;} | |
79 | // The list of FSM states | |
80 | struct Empty : public msm::front::state<my_visitable_state> | |
81 | { | |
82 | typedef mpl::vector<play> deferred_events; | |
83 | // every (optional) entry/exit methods get the event packed as boost::any. Not useful very often. | |
84 | template <class Event,class FSM> | |
85 | void on_entry(Event const&,FSM& ) {std::cout << "entering: Empty" << std::endl;} | |
86 | template <class Event,class FSM> | |
87 | void on_exit(Event const&,FSM& ) {std::cout << "leaving: Empty" << std::endl;} | |
88 | void accept(SomeVisitor& vis,int i) const | |
89 | { | |
90 | vis.visit_state(this,i); | |
91 | } | |
92 | }; | |
93 | struct Open : public msm::front::state<my_visitable_state> | |
94 | { | |
95 | typedef mpl::vector1<CDLoaded> flag_list; | |
96 | typedef mpl::vector<play> deferred_events; | |
97 | template <class Event,class FSM> | |
98 | void on_entry(Event const&,FSM& ) {std::cout << "entering: Open" << std::endl;} | |
99 | template <class Event,class FSM> | |
100 | void on_exit(Event const&,FSM& ) {std::cout << "leaving: Open" << std::endl;} | |
101 | void accept(SomeVisitor& vis,int i) const | |
102 | { | |
103 | vis.visit_state(this,i); | |
104 | } | |
105 | }; | |
106 | // a state needing a pointer to the containing state machine | |
107 | // and using for this the non-default policy | |
108 | // if policy used, set_sm_ptr is needed | |
109 | struct Stopped : public msm::front::state<my_visitable_state> | |
110 | { | |
111 | // when stopped, the CD is loaded | |
112 | typedef mpl::vector1<CDLoaded> flag_list; | |
113 | template <class Event,class FSM> | |
114 | void on_entry(Event const&,FSM& ) {std::cout << "entering: Stopped" << std::endl;} | |
115 | template <class Event,class FSM> | |
116 | void on_exit(Event const&,FSM& ) {std::cout << "leaving: Stopped" << std::endl;} | |
117 | }; | |
118 | // the player state machine contains a state which is himself a state machine | |
119 | // it demonstrates Shallow History: if the state gets activated with end_pause | |
120 | // then it will remember the last active state and reactivate it | |
121 | // also possible: AlwaysHistory, the last active state will always be reactivated | |
122 | // or NoHistory, always restart from the initial state | |
123 | struct Playing_ : public msm::front::state_machine_def<Playing_,my_visitable_state > | |
124 | { | |
125 | // when playing, the CD is loaded and we are in either pause or playing (duh) | |
126 | typedef mpl::vector2<PlayingPaused,CDLoaded> flag_list; | |
127 | template <class Event,class FSM> | |
128 | void on_entry(Event const&,FSM& ) {std::cout << "entering: Playing" << std::endl;} | |
129 | template <class Event,class FSM> | |
130 | void on_exit(Event const&,FSM& ) {std::cout << "leaving: Playing" << std::endl;} | |
131 | void accept(SomeVisitor& vis,int i) const | |
132 | { | |
133 | // note that visiting will recursively visit sub-states | |
134 | vis.visit_state(this,i); | |
135 | } | |
136 | // The list of FSM states | |
137 | // the Playing state machine contains a state which is himself a state machine | |
138 | // so we have a SM containing a SM containing a SM | |
139 | struct Song1_ : public msm::front::state_machine_def<Song1_,my_visitable_state> | |
140 | { | |
141 | typedef mpl::vector1<FirstSongPlaying> flag_list; | |
142 | template <class Event,class FSM> | |
143 | void on_entry(Event const&,FSM& ) {std::cout << "starting: First song" << std::endl;} | |
144 | template <class Event,class FSM> | |
145 | void on_exit(Event const&,FSM& ) {std::cout << "finishing: First Song" << std::endl;} | |
146 | void accept(SomeVisitor& vis,int i) const | |
147 | { | |
148 | vis.visit_state(this,i); | |
149 | } | |
150 | struct LightOn : public msm::front::state<my_visitable_state> | |
151 | { | |
152 | template <class Event,class FSM> | |
153 | void on_entry(Event const&,FSM& ) {std::cout << "starting: LightOn" << std::endl;} | |
154 | template <class Event,class FSM> | |
155 | void on_exit(Event const&,FSM& ) {std::cout << "finishing: LightOn" << std::endl;} | |
156 | }; | |
157 | struct LightOff : public msm::front::state<my_visitable_state> | |
158 | { | |
159 | template <class Event,class FSM> | |
160 | void on_entry(Event const&,FSM& ) {std::cout << "starting: LightOff" << std::endl;} | |
161 | template <class Event,class FSM> | |
162 | void on_exit(Event const&,FSM& ) {std::cout << "finishing: LightOff" << std::endl;} | |
163 | }; | |
164 | // the initial state. Must be defined | |
165 | typedef LightOn initial_state; | |
166 | // transition actions | |
167 | void turn_light_off(ThreeSec const&) { std::cout << "3s off::turn light off\n"; } | |
168 | // guard conditions | |
169 | ||
170 | typedef Song1_ s; // makes transition table cleaner | |
171 | // Transition table for Song1 | |
172 | struct transition_table : mpl::vector1< | |
173 | // Start Event Next Action Guard | |
174 | // +---------+-------------+---------+---------------------+----------------------+ | |
175 | a_row < LightOn , ThreeSec , LightOff, &s::turn_light_off > | |
176 | // +---------+-------------+---------+---------------------+----------------------+ | |
177 | > {}; | |
178 | // Replaces the default no-transition response. | |
179 | template <class FSM,class Event> | |
180 | void no_transition(Event const& e, FSM&,int state) | |
181 | { | |
182 | std::cout << "no transition from state " << state | |
183 | << " on event " << typeid(e).name() << std::endl; | |
184 | } | |
185 | }; | |
186 | typedef msm::back::state_machine<Song1_> Song1; | |
187 | ||
188 | struct Song2 : public msm::front::state<my_visitable_state> | |
189 | { | |
190 | template <class Event,class FSM> | |
191 | void on_entry(Event const&,FSM& ) {std::cout << "starting: Second song" << std::endl;} | |
192 | template <class Event,class FSM> | |
193 | void on_exit(Event const&,FSM& ) {std::cout << "finishing: Second Song" << std::endl;} | |
194 | }; | |
195 | struct Song3 : public msm::front::state<my_visitable_state> | |
196 | { | |
197 | template <class Event,class FSM> | |
198 | void on_entry(Event const&,FSM& ) {std::cout << "starting: Third song" << std::endl;} | |
199 | template <class Event,class FSM> | |
200 | void on_exit(Event const&,FSM& ) {std::cout << "finishing: Third Song" << std::endl;} | |
201 | }; | |
202 | // the initial state. Must be defined | |
203 | typedef Song1 initial_state; | |
204 | // transition actions | |
205 | void start_next_song(NextSong const&) { std::cout << "Playing::start_next_song\n"; } | |
206 | void start_prev_song(PreviousSong const&) { std::cout << "Playing::start_prev_song\n"; } | |
207 | // guard conditions | |
208 | ||
209 | typedef Playing_ pl; // makes transition table cleaner | |
210 | // Transition table for Playing | |
211 | struct transition_table : mpl::vector4< | |
212 | // Start Event Next Action Guard | |
213 | // +---------+-------------+---------+---------------------+----------------------+ | |
214 | a_row < Song1 , NextSong , Song2 , &pl::start_next_song >, | |
215 | a_row < Song2 , PreviousSong, Song1 , &pl::start_prev_song >, | |
216 | a_row < Song2 , NextSong , Song3 , &pl::start_next_song >, | |
217 | a_row < Song3 , PreviousSong, Song2 , &pl::start_prev_song > | |
218 | // +---------+-------------+---------+---------------------+----------------------+ | |
219 | > {}; | |
220 | // Replaces the default no-transition response. | |
221 | template <class FSM,class Event> | |
222 | void no_transition(Event const& e, FSM&,int state) | |
223 | { | |
224 | std::cout << "no transition from state " << state | |
225 | << " on event " << typeid(e).name() << std::endl; | |
226 | } | |
227 | }; | |
228 | typedef msm::back::state_machine<Playing_,msm::back::ShallowHistory<mpl::vector<end_pause> > > Playing; | |
229 | ||
230 | // the player state machine contains a state which is himself a state machine (2 of them, Playing and Paused) | |
231 | struct Paused_ : public msm::front::state_machine_def<Paused_,my_visitable_state> | |
232 | { | |
233 | typedef mpl::vector2<PlayingPaused,CDLoaded> flag_list; | |
234 | template <class Event,class FSM> | |
235 | void on_entry(Event const&,FSM& ) {std::cout << "entering: Paused" << std::endl;} | |
236 | template <class Event,class FSM> | |
237 | void on_exit(Event const&,FSM& ) {std::cout << "leaving: Paused" << std::endl;} | |
238 | ||
239 | // The list of FSM states | |
240 | struct StartBlinking : public msm::front::state<my_visitable_state> | |
241 | { | |
242 | template <class Event,class FSM> | |
243 | void on_entry(Event const&,FSM& ) {std::cout << "starting: StartBlinking" << std::endl;} | |
244 | template <class Event,class FSM> | |
245 | void on_exit(Event const&,FSM& ) {std::cout << "finishing: StartBlinking" << std::endl;} | |
246 | }; | |
247 | struct StopBlinking : public msm::front::state<my_visitable_state> | |
248 | { | |
249 | template <class Event,class FSM> | |
250 | void on_entry(Event const&,FSM& ) {std::cout << "starting: StopBlinking" << std::endl;} | |
251 | template <class Event,class FSM> | |
252 | void on_exit(Event const&,FSM& ) {std::cout << "finishing: StopBlinking" << std::endl;} | |
253 | }; | |
254 | // the initial state. Must be defined | |
255 | typedef StartBlinking initial_state; | |
256 | // transition actions | |
257 | void start_blinking(TenSec const&) { std::cout << "Paused::start_blinking\n"; } | |
258 | void stop_blinking(TenSec const&) { std::cout << "Paused::stop_blinking\n"; } | |
259 | // guard conditions | |
260 | ||
261 | typedef Paused_ pa; // makes transition table cleaner | |
262 | // Transition table | |
263 | struct transition_table : mpl::vector2< | |
264 | // Start Event Next Action Guard | |
265 | // +---------------+-------------+--------------+---------------------+----------------------+ | |
266 | a_row < StartBlinking , TenSec , StopBlinking , &pa::stop_blinking >, | |
267 | a_row < StopBlinking , TenSec , StartBlinking , &pa::start_blinking > | |
268 | // +---------------+-------------+---------------+--------------------+----------------------+ | |
269 | > {}; | |
270 | // Replaces the default no-transition response. | |
271 | template <class FSM,class Event> | |
272 | void no_transition(Event const& e, FSM&,int state) | |
273 | { | |
274 | std::cout << "no transition from state " << state | |
275 | << " on event " << typeid(e).name() << std::endl; | |
276 | } | |
277 | }; | |
278 | typedef msm::back::state_machine<Paused_> Paused; | |
279 | ||
280 | struct SleepMode : public msm::front::state<my_visitable_state> | |
281 | { | |
282 | }; // dummy state just to test the automatic id generation | |
283 | ||
284 | struct AllOk : public msm::front::state<my_visitable_state> | |
285 | { | |
286 | template <class Event,class FSM> | |
287 | void on_entry(Event const&,FSM& ) {std::cout << "starting: AllOk" << std::endl;} | |
288 | template <class Event,class FSM> | |
289 | void on_exit(Event const&,FSM& ) {std::cout << "finishing: AllOk" << std::endl;} | |
290 | }; | |
291 | struct ErrorMode : //public terminate_state<> | |
292 | public msm::front::interrupt_state<end_error,my_visitable_state> | |
293 | { | |
294 | template <class Event,class FSM> | |
295 | void on_entry(Event const&,FSM& ) {std::cout << "starting: ErrorMode" << std::endl;} | |
296 | template <class Event,class FSM> | |
297 | void on_exit(Event const&,FSM& ) {std::cout << "finishing: ErrorMode" << std::endl;} | |
298 | }; | |
299 | ||
300 | // the initial state of the player SM. Must be defined | |
301 | typedef mpl::vector<Empty,AllOk> initial_state; | |
302 | //typedef Empty initial_state; // this is to have only one active state | |
303 | ||
304 | // transition actions | |
305 | void start_playback(play const&) { std::cout << "player::start_playback\n"; } | |
306 | void open_drawer(open_close const&) { std::cout << "player::open_drawer\n"; } | |
307 | void close_drawer(open_close const&) { std::cout << "player::close_drawer\n"; } | |
308 | void store_cd_info(cd_detected const&) | |
309 | { | |
310 | std::cout << "player::store_cd_info\n"; | |
311 | // generate another event to test the queue | |
312 | //process_event(play()); | |
313 | } | |
314 | void stop_playback(stop const&) { std::cout << "player::stop_playback\n"; } | |
315 | void pause_playback(pause const&) { std::cout << "player::pause_playback\n"; } | |
316 | void resume_playback(end_pause const&) { std::cout << "player::resume_playback\n"; } | |
317 | void stop_and_open(open_close const&) { std::cout << "player::stop_and_open\n"; } | |
318 | void stopped_again(stop const&){std::cout << "player::stopped_again\n";} | |
319 | void start_sleep(go_sleep const&) { } | |
320 | void report_error(error_found const&) {std::cout << "player::report_error\n";} | |
321 | void report_end_error(end_error const&) {std::cout << "player::report_end_error\n";} | |
322 | // guard conditions | |
323 | ||
324 | ||
325 | typedef player_ p; // makes transition table cleaner | |
326 | ||
327 | // Transition table for player | |
328 | struct transition_table : mpl::vector< | |
329 | // Start Event Next Action Guard | |
330 | // +---------+-------------+---------+---------------------+----------------------+ | |
331 | a_row < Stopped , play , Playing , &p::start_playback >, | |
332 | a_row < Stopped , open_close , Open , &p::open_drawer >, | |
333 | a_row < Stopped , stop , Stopped , &p::stopped_again >, | |
334 | // +---------+-------------+---------+---------------------+----------------------+ | |
335 | a_row < Open , open_close , Empty , &p::close_drawer >, | |
336 | // +---------+-------------+---------+---------------------+----------------------+ | |
337 | a_row < Empty , open_close , Open , &p::open_drawer >, | |
338 | a_row < Empty , cd_detected , Stopped , &p::store_cd_info >, | |
339 | // +---------+-------------+---------+---------------------+----------------------+ | |
340 | a_row < Playing , stop , Stopped , &p::stop_playback >, | |
341 | a_row < Playing , pause , Paused , &p::pause_playback >, | |
342 | a_row < Playing , open_close , Open , &p::stop_and_open >, | |
343 | // +---------+-------------+---------+---------------------+----------------------+ | |
344 | a_row < Paused , end_pause , Playing , &p::resume_playback >, | |
345 | a_row < Paused , stop , Stopped , &p::stop_playback >, | |
346 | a_row < Paused , open_close , Open , &p::stop_and_open >, | |
347 | a_row < Paused , go_sleep ,SleepMode, &p::start_sleep >, | |
348 | // +---------+-------------+---------+---------------------+----------------------+ | |
349 | a_row < AllOk , error_found ,ErrorMode, &p::report_error >, | |
350 | a_row <ErrorMode,end_error ,AllOk , &p::report_end_error > | |
351 | // +---------+-------------+---------+---------------------+----------------------+ | |
352 | > {}; | |
353 | ||
354 | // Replaces the default no-transition response. | |
355 | template <class FSM,class Event> | |
356 | void no_transition(Event const& e, FSM&,int state) | |
357 | { | |
358 | std::cout << "no transition from state " << state | |
359 | << " on event " << typeid(e).name() << std::endl; | |
360 | } | |
361 | }; | |
362 | ||
363 | // back-end | |
364 | typedef msm::back::state_machine<player_> player; | |
365 | ||
366 | // | |
367 | // Testing utilities. | |
368 | // | |
369 | ||
370 | void pstate(player const& p) | |
371 | { | |
372 | static char const* const state_names[] = { "Stopped", "Open", "Empty", "Playing", "Paused","AllOk","ErrorMode","SleepMode" }; | |
373 | for (unsigned int i=0;i<player::nr_regions::value;++i) | |
374 | { | |
375 | std::cout << " -> " << state_names[p.current_state()[i]] << std::endl; | |
376 | } | |
377 | } | |
378 | void test() | |
379 | { | |
380 | player p; | |
381 | // needed to start the highest-level SM. This will call on_entry and mark the start of the SM | |
382 | p.start(); | |
383 | std::cout << "CDLoaded active:" << std::boolalpha << p.is_flag_active<CDLoaded>() << std::endl; //=> false (no CD yet) | |
384 | ||
385 | // test deferred event | |
386 | // deferred in Empty and Open, will be handled only after event cd_detected | |
387 | p.process_event(play()); | |
388 | ||
389 | // go to Open, call on_exit on Empty, then action, then on_entry on Open | |
390 | p.process_event(open_close()); pstate(p); | |
391 | // visiting Paused and AllOk, but only Paused cares | |
392 | SomeVisitor vis; | |
393 | p.visit_current_states(boost::ref(vis),1); | |
394 | p.process_event(open_close()); pstate(p); | |
395 | // visiting Empty and AllOk, but only Empty cares | |
396 | p.visit_current_states(boost::ref(vis),2); | |
397 | ||
398 | ||
399 | p.process_event(cd_detected("louie, louie")); | |
400 | // no need to call play() as the previous event does it in its action method | |
401 | //p.process_event(play()); | |
402 | // at this point, Play is active, along FirstSong and LightOn | |
403 | pstate(p); | |
404 | // visiting Playing+Song1 and AllOk, but only Playing+Song1 care | |
405 | p.visit_current_states(boost::ref(vis),3); | |
406 | ||
407 | std::cout << "PlayingPaused active:" << std::boolalpha << p.is_flag_active<PlayingPaused>() << std::endl;//=> true | |
408 | // call on_exit on LightOn,FirstSong,Play like stated in the UML spec. | |
409 | // and of course on_entry on Paused and StartBlinking | |
410 | p.process_event(pause()); pstate(p); | |
411 | std::cout << "PlayingPaused active:" << std::boolalpha << p.is_flag_active<PlayingPaused>() << std::endl;//=> true | |
412 | // forward events to Paused | |
413 | p.process_event(TenSec()); | |
414 | p.process_event(TenSec()); | |
415 | // go back to Playing | |
416 | p.process_event(end_pause()); pstate(p); | |
417 | std::cout << "FirstSong active:" << std::boolalpha << p.is_flag_active<FirstSongPlaying>() << std::endl; //=> true | |
418 | p.process_event(ThreeSec()); pstate(p); | |
419 | p.process_event(NextSong());pstate(p); | |
420 | // We are now in second song, Flag inactive | |
421 | std::cout << "FirstSong active:" << std::boolalpha << p.is_flag_active<FirstSongPlaying>() << std::endl;//=> false | |
422 | // visiting Playing+Song2 and AllOk, but only Playing cares | |
423 | p.visit_current_states(boost::ref(vis),4); | |
424 | ||
425 | p.process_event(NextSong());pstate(p); | |
426 | // 2nd song active | |
427 | p.process_event(PreviousSong());pstate(p); | |
428 | // Pause | |
429 | p.process_event(pause()); pstate(p); | |
430 | // go back to Playing | |
431 | // but end_pause is an event activating the History | |
432 | // => keep the last active State (SecondSong) | |
433 | p.process_event(end_pause()); pstate(p); | |
434 | // test of an event from a state to itself. According to UML spec, call again exit/entry from Stopped | |
435 | p.process_event(stop()); pstate(p); | |
436 | p.process_event(stop()); pstate(p); | |
437 | std::cout << "CDLoaded active:" << std::boolalpha << p.is_flag_active<CDLoaded>() << std::endl;//=> true | |
438 | std::cout << "PlayingPaused active:" << std::boolalpha << p.is_flag_active<PlayingPaused>() << std::endl;//=> false | |
439 | std::cout << "FirstSong active:" << std::boolalpha << p.is_flag_active<FirstSongPlaying>() << std::endl;//=> false | |
440 | std::cout << "CDLoaded active with AND:" << std::boolalpha << p.is_flag_active<CDLoaded,player::Flag_AND>() << std::endl;//=> false | |
441 | std::cout << "CDLoaded active with OR:" << std::boolalpha << p.is_flag_active<CDLoaded,player::Flag_OR>() << std::endl;//=> true | |
442 | ||
443 | // go back to Playing | |
444 | // but play is not leading to Shallow History => do not remember the last active State (SecondSong) | |
445 | // and activate again FirstSong and LightOn | |
446 | p.process_event(play()); pstate(p); | |
447 | p.process_event(error_found()); pstate(p); | |
448 | ||
449 | // try generating more events | |
450 | std::cout << "Trying to generate another event" << std::endl; // will not work, fsm is terminated or interrupted | |
451 | p.process_event(NextSong());pstate(p); | |
452 | ||
453 | std::cout << "Trying to end the error" << std::endl; // will work only if ErrorMode is interrupt state | |
454 | p.process_event(end_error());pstate(p); | |
455 | std::cout << "Trying to generate another event" << std::endl; // will work only if ErrorMode is interrupt state | |
456 | p.process_event(NextSong());pstate(p); | |
457 | ||
458 | std::cout << "Simulate error. Event play is not valid" << std::endl; | |
459 | p.process_event(play()); pstate(p); | |
460 | } | |
461 | } | |
462 | ||
463 | int main() | |
464 | { | |
465 | test(); | |
466 | return 0; | |
467 | } | |
468 | ||
469 |