| // Copyright 2010 Christophe Henry |
| // henry UNDERSCORE christophe AT hotmail DOT com |
| // This is an extended version of the state machine available in the boost::mpl library |
| // Distributed under the same license as the original. |
| // Copyright for the original version: |
| // Copyright 2005 David Abrahams and Aleksey Gurtovoy. Distributed |
| // under the Boost Software License, Version 1.0. (See accompanying |
| // file LICENSE_1_0.txt or copy at |
| // http://www.boost.org/LICENSE_1_0.txt) |
| |
| #include <iostream> |
| #include <string> |
| #include "boost/mpl/vector/vector30.hpp" |
| |
| #include <boost/msm/back/state_machine.hpp> |
| #include <boost/msm/front/state_machine_def.hpp> |
| #include <boost/msm/back/tools.hpp> |
| |
| using namespace std; |
| namespace msm = boost::msm; |
| |
| namespace // Concrete FSM implementation |
| { |
| // events |
| struct play {}; |
| struct end_pause {}; |
| struct stop {}; |
| struct pause {}; |
| struct open_close {}; |
| struct NextSong {}; |
| struct PreviousSong {}; |
| struct ThreeSec {}; |
| struct TenSec {}; |
| struct go_sleep {}; |
| struct error_found {}; |
| struct end_error {}; |
| |
| // Flags. Allow information about a property of the current state |
| struct PlayingPaused{}; |
| struct CDLoaded {}; |
| struct FirstSongPlaying {}; |
| |
| // A "complicated" event type that carries some data. |
| struct cd_detected |
| { |
| cd_detected(std::string name) |
| : name(name) |
| {} |
| |
| std::string name; |
| }; |
| // an easy visitor |
| struct SomeVisitor |
| { |
| template <class T> |
| void visit_state(T* astate,int i) |
| { |
| std::cout << "visiting state:" << typeid(*astate).name() |
| << " with data:" << i << std::endl; |
| } |
| }; |
| // overwrite of the base state (not default) |
| struct my_visitable_state |
| { |
| // signature of the accept function |
| typedef msm::back::args<void,SomeVisitor&,int> accept_sig; |
| |
| // we also want polymorphic states |
| virtual ~my_visitable_state() {} |
| // default implementation for states who do not need to be visited |
| void accept(SomeVisitor&,int) const {} |
| }; |
| |
| // Concrete FSM implementation |
| struct player_ : public msm::front::state_machine_def<player_,my_visitable_state> |
| { |
| template <class Event,class FSM> |
| void on_entry(Event const&,FSM& ) {std::cout << "starting: player" << std::endl;} |
| // The list of FSM states |
| struct Empty : public msm::front::state<my_visitable_state> |
| { |
| typedef mpl::vector<play> deferred_events; |
| // every (optional) entry/exit methods get the event packed as boost::any. Not useful very often. |
| template <class Event,class FSM> |
| void on_entry(Event const&,FSM& ) {std::cout << "entering: Empty" << std::endl;} |
| template <class Event,class FSM> |
| void on_exit(Event const&,FSM& ) {std::cout << "leaving: Empty" << std::endl;} |
| void accept(SomeVisitor& vis,int i) const |
| { |
| vis.visit_state(this,i); |
| } |
| }; |
| struct Open : public msm::front::state<my_visitable_state> |
| { |
| typedef mpl::vector1<CDLoaded> flag_list; |
| typedef mpl::vector<play> deferred_events; |
| template <class Event,class FSM> |
| void on_entry(Event const&,FSM& ) {std::cout << "entering: Open" << std::endl;} |
| template <class Event,class FSM> |
| void on_exit(Event const&,FSM& ) {std::cout << "leaving: Open" << std::endl;} |
| void accept(SomeVisitor& vis,int i) const |
| { |
| vis.visit_state(this,i); |
| } |
| }; |
| // a state needing a pointer to the containing state machine |
| // and using for this the non-default policy |
| // if policy used, set_sm_ptr is needed |
| struct Stopped : public msm::front::state<my_visitable_state> |
| { |
| // when stopped, the CD is loaded |
| typedef mpl::vector1<CDLoaded> flag_list; |
| template <class Event,class FSM> |
| void on_entry(Event const&,FSM& ) {std::cout << "entering: Stopped" << std::endl;} |
| template <class Event,class FSM> |
| void on_exit(Event const&,FSM& ) {std::cout << "leaving: Stopped" << std::endl;} |
| }; |
| // the player state machine contains a state which is himself a state machine |
| // it demonstrates Shallow History: if the state gets activated with end_pause |
| // then it will remember the last active state and reactivate it |
| // also possible: AlwaysHistory, the last active state will always be reactivated |
| // or NoHistory, always restart from the initial state |
| struct Playing_ : public msm::front::state_machine_def<Playing_,my_visitable_state > |
| { |
| // when playing, the CD is loaded and we are in either pause or playing (duh) |
| typedef mpl::vector2<PlayingPaused,CDLoaded> flag_list; |
| template <class Event,class FSM> |
| void on_entry(Event const&,FSM& ) {std::cout << "entering: Playing" << std::endl;} |
| template <class Event,class FSM> |
| void on_exit(Event const&,FSM& ) {std::cout << "leaving: Playing" << std::endl;} |
| void accept(SomeVisitor& vis,int i) const |
| { |
| // note that visiting will recursively visit sub-states |
| vis.visit_state(this,i); |
| } |
| // The list of FSM states |
| // the Playing state machine contains a state which is himself a state machine |
| // so we have a SM containing a SM containing a SM |
| struct Song1_ : public msm::front::state_machine_def<Song1_,my_visitable_state> |
| { |
| typedef mpl::vector1<FirstSongPlaying> flag_list; |
| template <class Event,class FSM> |
| void on_entry(Event const&,FSM& ) {std::cout << "starting: First song" << std::endl;} |
| template <class Event,class FSM> |
| void on_exit(Event const&,FSM& ) {std::cout << "finishing: First Song" << std::endl;} |
| void accept(SomeVisitor& vis,int i) const |
| { |
| vis.visit_state(this,i); |
| } |
| struct LightOn : public msm::front::state<my_visitable_state> |
| { |
| template <class Event,class FSM> |
| void on_entry(Event const&,FSM& ) {std::cout << "starting: LightOn" << std::endl;} |
| template <class Event,class FSM> |
| void on_exit(Event const&,FSM& ) {std::cout << "finishing: LightOn" << std::endl;} |
| }; |
| struct LightOff : public msm::front::state<my_visitable_state> |
| { |
| template <class Event,class FSM> |
| void on_entry(Event const&,FSM& ) {std::cout << "starting: LightOff" << std::endl;} |
| template <class Event,class FSM> |
| void on_exit(Event const&,FSM& ) {std::cout << "finishing: LightOff" << std::endl;} |
| }; |
| // the initial state. Must be defined |
| typedef LightOn initial_state; |
| // transition actions |
| void turn_light_off(ThreeSec const&) { std::cout << "3s off::turn light off\n"; } |
| // guard conditions |
| |
| typedef Song1_ s; // makes transition table cleaner |
| // Transition table for Song1 |
| struct transition_table : mpl::vector1< |
| // Start Event Next Action Guard |
| // +---------+-------------+---------+---------------------+----------------------+ |
| a_row < LightOn , ThreeSec , LightOff, &s::turn_light_off > |
| // +---------+-------------+---------+---------------------+----------------------+ |
| > {}; |
| // Replaces the default no-transition response. |
| template <class FSM,class Event> |
| void no_transition(Event const& e, FSM&,int state) |
| { |
| std::cout << "no transition from state " << state |
| << " on event " << typeid(e).name() << std::endl; |
| } |
| }; |
| typedef msm::back::state_machine<Song1_> Song1; |
| |
| struct Song2 : public msm::front::state<my_visitable_state> |
| { |
| template <class Event,class FSM> |
| void on_entry(Event const&,FSM& ) {std::cout << "starting: Second song" << std::endl;} |
| template <class Event,class FSM> |
| void on_exit(Event const&,FSM& ) {std::cout << "finishing: Second Song" << std::endl;} |
| }; |
| struct Song3 : public msm::front::state<my_visitable_state> |
| { |
| template <class Event,class FSM> |
| void on_entry(Event const&,FSM& ) {std::cout << "starting: Third song" << std::endl;} |
| template <class Event,class FSM> |
| void on_exit(Event const&,FSM& ) {std::cout << "finishing: Third Song" << std::endl;} |
| }; |
| // the initial state. Must be defined |
| typedef Song1 initial_state; |
| // transition actions |
| void start_next_song(NextSong const&) { std::cout << "Playing::start_next_song\n"; } |
| void start_prev_song(PreviousSong const&) { std::cout << "Playing::start_prev_song\n"; } |
| // guard conditions |
| |
| typedef Playing_ pl; // makes transition table cleaner |
| // Transition table for Playing |
| struct transition_table : mpl::vector4< |
| // Start Event Next Action Guard |
| // +---------+-------------+---------+---------------------+----------------------+ |
| a_row < Song1 , NextSong , Song2 , &pl::start_next_song >, |
| a_row < Song2 , PreviousSong, Song1 , &pl::start_prev_song >, |
| a_row < Song2 , NextSong , Song3 , &pl::start_next_song >, |
| a_row < Song3 , PreviousSong, Song2 , &pl::start_prev_song > |
| // +---------+-------------+---------+---------------------+----------------------+ |
| > {}; |
| // Replaces the default no-transition response. |
| template <class FSM,class Event> |
| void no_transition(Event const& e, FSM&,int state) |
| { |
| std::cout << "no transition from state " << state |
| << " on event " << typeid(e).name() << std::endl; |
| } |
| }; |
| typedef msm::back::state_machine<Playing_,msm::back::ShallowHistory<mpl::vector<end_pause> > > Playing; |
| |
| // the player state machine contains a state which is himself a state machine (2 of them, Playing and Paused) |
| struct Paused_ : public msm::front::state_machine_def<Paused_,my_visitable_state> |
| { |
| typedef mpl::vector2<PlayingPaused,CDLoaded> flag_list; |
| template <class Event,class FSM> |
| void on_entry(Event const&,FSM& ) {std::cout << "entering: Paused" << std::endl;} |
| template <class Event,class FSM> |
| void on_exit(Event const&,FSM& ) {std::cout << "leaving: Paused" << std::endl;} |
| |
| // The list of FSM states |
| struct StartBlinking : public msm::front::state<my_visitable_state> |
| { |
| template <class Event,class FSM> |
| void on_entry(Event const&,FSM& ) {std::cout << "starting: StartBlinking" << std::endl;} |
| template <class Event,class FSM> |
| void on_exit(Event const&,FSM& ) {std::cout << "finishing: StartBlinking" << std::endl;} |
| }; |
| struct StopBlinking : public msm::front::state<my_visitable_state> |
| { |
| template <class Event,class FSM> |
| void on_entry(Event const&,FSM& ) {std::cout << "starting: StopBlinking" << std::endl;} |
| template <class Event,class FSM> |
| void on_exit(Event const&,FSM& ) {std::cout << "finishing: StopBlinking" << std::endl;} |
| }; |
| // the initial state. Must be defined |
| typedef StartBlinking initial_state; |
| // transition actions |
| void start_blinking(TenSec const&) { std::cout << "Paused::start_blinking\n"; } |
| void stop_blinking(TenSec const&) { std::cout << "Paused::stop_blinking\n"; } |
| // guard conditions |
| |
| typedef Paused_ pa; // makes transition table cleaner |
| // Transition table |
| struct transition_table : mpl::vector2< |
| // Start Event Next Action Guard |
| // +---------------+-------------+--------------+---------------------+----------------------+ |
| a_row < StartBlinking , TenSec , StopBlinking , &pa::stop_blinking >, |
| a_row < StopBlinking , TenSec , StartBlinking , &pa::start_blinking > |
| // +---------------+-------------+---------------+--------------------+----------------------+ |
| > {}; |
| // Replaces the default no-transition response. |
| template <class FSM,class Event> |
| void no_transition(Event const& e, FSM&,int state) |
| { |
| std::cout << "no transition from state " << state |
| << " on event " << typeid(e).name() << std::endl; |
| } |
| }; |
| typedef msm::back::state_machine<Paused_> Paused; |
| |
| struct SleepMode : public msm::front::state<my_visitable_state> |
| { |
| }; // dummy state just to test the automatic id generation |
| |
| struct AllOk : public msm::front::state<my_visitable_state> |
| { |
| template <class Event,class FSM> |
| void on_entry(Event const&,FSM& ) {std::cout << "starting: AllOk" << std::endl;} |
| template <class Event,class FSM> |
| void on_exit(Event const&,FSM& ) {std::cout << "finishing: AllOk" << std::endl;} |
| }; |
| struct ErrorMode : //public terminate_state<> |
| public msm::front::interrupt_state<end_error,my_visitable_state> |
| { |
| template <class Event,class FSM> |
| void on_entry(Event const&,FSM& ) {std::cout << "starting: ErrorMode" << std::endl;} |
| template <class Event,class FSM> |
| void on_exit(Event const&,FSM& ) {std::cout << "finishing: ErrorMode" << std::endl;} |
| }; |
| |
| // the initial state of the player SM. Must be defined |
| typedef mpl::vector<Empty,AllOk> initial_state; |
| //typedef Empty initial_state; // this is to have only one active state |
| |
| // transition actions |
| void start_playback(play const&) { std::cout << "player::start_playback\n"; } |
| void open_drawer(open_close const&) { std::cout << "player::open_drawer\n"; } |
| void close_drawer(open_close const&) { std::cout << "player::close_drawer\n"; } |
| void store_cd_info(cd_detected const&) |
| { |
| std::cout << "player::store_cd_info\n"; |
| // generate another event to test the queue |
| //process_event(play()); |
| } |
| void stop_playback(stop const&) { std::cout << "player::stop_playback\n"; } |
| void pause_playback(pause const&) { std::cout << "player::pause_playback\n"; } |
| void resume_playback(end_pause const&) { std::cout << "player::resume_playback\n"; } |
| void stop_and_open(open_close const&) { std::cout << "player::stop_and_open\n"; } |
| void stopped_again(stop const&){std::cout << "player::stopped_again\n";} |
| void start_sleep(go_sleep const&) { } |
| void report_error(error_found const&) {std::cout << "player::report_error\n";} |
| void report_end_error(end_error const&) {std::cout << "player::report_end_error\n";} |
| // guard conditions |
| |
| |
| typedef player_ p; // makes transition table cleaner |
| |
| // Transition table for player |
| struct transition_table : mpl::vector< |
| // Start Event Next Action Guard |
| // +---------+-------------+---------+---------------------+----------------------+ |
| a_row < Stopped , play , Playing , &p::start_playback >, |
| a_row < Stopped , open_close , Open , &p::open_drawer >, |
| a_row < Stopped , stop , Stopped , &p::stopped_again >, |
| // +---------+-------------+---------+---------------------+----------------------+ |
| a_row < Open , open_close , Empty , &p::close_drawer >, |
| // +---------+-------------+---------+---------------------+----------------------+ |
| a_row < Empty , open_close , Open , &p::open_drawer >, |
| a_row < Empty , cd_detected , Stopped , &p::store_cd_info >, |
| // +---------+-------------+---------+---------------------+----------------------+ |
| a_row < Playing , stop , Stopped , &p::stop_playback >, |
| a_row < Playing , pause , Paused , &p::pause_playback >, |
| a_row < Playing , open_close , Open , &p::stop_and_open >, |
| // +---------+-------------+---------+---------------------+----------------------+ |
| a_row < Paused , end_pause , Playing , &p::resume_playback >, |
| a_row < Paused , stop , Stopped , &p::stop_playback >, |
| a_row < Paused , open_close , Open , &p::stop_and_open >, |
| a_row < Paused , go_sleep ,SleepMode, &p::start_sleep >, |
| // +---------+-------------+---------+---------------------+----------------------+ |
| a_row < AllOk , error_found ,ErrorMode, &p::report_error >, |
| a_row <ErrorMode,end_error ,AllOk , &p::report_end_error > |
| // +---------+-------------+---------+---------------------+----------------------+ |
| > {}; |
| |
| // Replaces the default no-transition response. |
| template <class FSM,class Event> |
| void no_transition(Event const& e, FSM&,int state) |
| { |
| std::cout << "no transition from state " << state |
| << " on event " << typeid(e).name() << std::endl; |
| } |
| }; |
| |
| // back-end |
| typedef msm::back::state_machine<player_> player; |
| |
| // |
| // Testing utilities. |
| // |
| |
| void pstate(player const& p) |
| { |
| static char const* const state_names[] = { "Stopped", "Open", "Empty", "Playing", "Paused","AllOk","ErrorMode","SleepMode" }; |
| for (unsigned int i=0;i<player::nr_regions::value;++i) |
| { |
| std::cout << " -> " << state_names[p.current_state()[i]] << std::endl; |
| } |
| } |
| void test() |
| { |
| player p; |
| // needed to start the highest-level SM. This will call on_entry and mark the start of the SM |
| p.start(); |
| std::cout << "CDLoaded active:" << std::boolalpha << p.is_flag_active<CDLoaded>() << std::endl; //=> false (no CD yet) |
| |
| // test deferred event |
| // deferred in Empty and Open, will be handled only after event cd_detected |
| p.process_event(play()); |
| |
| // go to Open, call on_exit on Empty, then action, then on_entry on Open |
| p.process_event(open_close()); pstate(p); |
| // visiting Paused and AllOk, but only Paused cares |
| SomeVisitor vis; |
| p.visit_current_states(boost::ref(vis),1); |
| p.process_event(open_close()); pstate(p); |
| // visiting Empty and AllOk, but only Empty cares |
| p.visit_current_states(boost::ref(vis),2); |
| |
| |
| p.process_event(cd_detected("louie, louie")); |
| // no need to call play() as the previous event does it in its action method |
| //p.process_event(play()); |
| // at this point, Play is active, along FirstSong and LightOn |
| pstate(p); |
| // visiting Playing+Song1 and AllOk, but only Playing+Song1 care |
| p.visit_current_states(boost::ref(vis),3); |
| |
| std::cout << "PlayingPaused active:" << std::boolalpha << p.is_flag_active<PlayingPaused>() << std::endl;//=> true |
| // call on_exit on LightOn,FirstSong,Play like stated in the UML spec. |
| // and of course on_entry on Paused and StartBlinking |
| p.process_event(pause()); pstate(p); |
| std::cout << "PlayingPaused active:" << std::boolalpha << p.is_flag_active<PlayingPaused>() << std::endl;//=> true |
| // forward events to Paused |
| p.process_event(TenSec()); |
| p.process_event(TenSec()); |
| // go back to Playing |
| p.process_event(end_pause()); pstate(p); |
| std::cout << "FirstSong active:" << std::boolalpha << p.is_flag_active<FirstSongPlaying>() << std::endl; //=> true |
| p.process_event(ThreeSec()); pstate(p); |
| p.process_event(NextSong());pstate(p); |
| // We are now in second song, Flag inactive |
| std::cout << "FirstSong active:" << std::boolalpha << p.is_flag_active<FirstSongPlaying>() << std::endl;//=> false |
| // visiting Playing+Song2 and AllOk, but only Playing cares |
| p.visit_current_states(boost::ref(vis),4); |
| |
| p.process_event(NextSong());pstate(p); |
| // 2nd song active |
| p.process_event(PreviousSong());pstate(p); |
| // Pause |
| p.process_event(pause()); pstate(p); |
| // go back to Playing |
| // but end_pause is an event activating the History |
| // => keep the last active State (SecondSong) |
| p.process_event(end_pause()); pstate(p); |
| // test of an event from a state to itself. According to UML spec, call again exit/entry from Stopped |
| p.process_event(stop()); pstate(p); |
| p.process_event(stop()); pstate(p); |
| std::cout << "CDLoaded active:" << std::boolalpha << p.is_flag_active<CDLoaded>() << std::endl;//=> true |
| std::cout << "PlayingPaused active:" << std::boolalpha << p.is_flag_active<PlayingPaused>() << std::endl;//=> false |
| std::cout << "FirstSong active:" << std::boolalpha << p.is_flag_active<FirstSongPlaying>() << std::endl;//=> false |
| std::cout << "CDLoaded active with AND:" << std::boolalpha << p.is_flag_active<CDLoaded,player::Flag_AND>() << std::endl;//=> false |
| std::cout << "CDLoaded active with OR:" << std::boolalpha << p.is_flag_active<CDLoaded,player::Flag_OR>() << std::endl;//=> true |
| |
| // go back to Playing |
| // but play is not leading to Shallow History => do not remember the last active State (SecondSong) |
| // and activate again FirstSong and LightOn |
| p.process_event(play()); pstate(p); |
| p.process_event(error_found()); pstate(p); |
| |
| // try generating more events |
| std::cout << "Trying to generate another event" << std::endl; // will not work, fsm is terminated or interrupted |
| p.process_event(NextSong());pstate(p); |
| |
| std::cout << "Trying to end the error" << std::endl; // will work only if ErrorMode is interrupt state |
| p.process_event(end_error());pstate(p); |
| std::cout << "Trying to generate another event" << std::endl; // will work only if ErrorMode is interrupt state |
| p.process_event(NextSong());pstate(p); |
| |
| std::cout << "Simulate error. Event play is not valid" << std::endl; |
| p.process_event(play()); pstate(p); |
| } |
| } |
| |
| int main() |
| { |
| test(); |
| return 0; |
| } |
| |
| |