libs/msm/doc/HTML/examples/SM-2Arg.cpp
// 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; }