libs/msm/doc/HTML/examples/OrthogonalDeferredEuml.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 <vector> #include <iostream> #include <boost/msm/back/state_machine.hpp> #include <boost/msm/front/euml/euml.hpp> using namespace std; using namespace boost::msm::front::euml; namespace msm = boost::msm; // entry/exit/action/guard logging functors #include "logging_functors.h" namespace // Concrete FSM implementation { // events BOOST_MSM_EUML_EVENT(play) BOOST_MSM_EUML_EVENT(end_pause) BOOST_MSM_EUML_EVENT(stop) BOOST_MSM_EUML_EVENT(pause) BOOST_MSM_EUML_EVENT(open_close) BOOST_MSM_EUML_EVENT(next_song) BOOST_MSM_EUML_EVENT(previous_song) BOOST_MSM_EUML_EVENT(end_error) BOOST_MSM_EUML_EVENT(error_found) // A "complicated" event type that carries some data. BOOST_MSM_EUML_DECLARE_ATTRIBUTE(std::string,cd_name) BOOST_MSM_EUML_DECLARE_ATTRIBUTE(DiskTypeEnum,cd_type) BOOST_MSM_EUML_ATTRIBUTES((attributes_ << cd_name << cd_type ), cd_detected_attributes) BOOST_MSM_EUML_EVENT_WITH_ATTRIBUTES(cd_detected,cd_detected_attributes) // Flags. Allow information about a property of the current state BOOST_MSM_EUML_FLAG(PlayingPaused) BOOST_MSM_EUML_FLAG(CDLoaded) BOOST_MSM_EUML_FLAG(FirstSongPlaying) // Concrete FSM implementation // The list of FSM states BOOST_MSM_EUML_STATE(( Empty_Entry, Empty_Exit, attributes_ << no_attributes_, configure_ << play // defer play ), Empty) BOOST_MSM_EUML_STATE(( Open_Entry, Open_Exit, attributes_ << no_attributes_, configure_<< CDLoaded << play // defer play, flag state with CDLoaded ), Open) BOOST_MSM_EUML_STATE(( Stopped_Entry, Stopped_Exit, attributes_ << no_attributes_, configure_<< CDLoaded // flag state with CDLoaded ), Stopped) // state not defining any entry or exit BOOST_MSM_EUML_STATE(( no_action, no_action, attributes_ << no_attributes_, configure_<< PlayingPaused << CDLoaded // flag state with CDLoaded and PlayingPaused ), Paused) BOOST_MSM_EUML_STATE(( AllOk_Entry,AllOk_Exit ),AllOk) // a terminate state //BOOST_MSM_EUML_TERMINATE_STATE(( ErrorMode_Entry,ErrorMode_Exit ),ErrorMode) // or as an interrupt state BOOST_MSM_EUML_INTERRUPT_STATE(( end_error,ErrorMode_Entry,ErrorMode_Exit ),ErrorMode) // Playing is now a state machine itself. // It has 3 substates BOOST_MSM_EUML_STATE(( Song1_Entry, Song1_Exit, attributes_ << no_attributes_, configure_<< FirstSongPlaying ),Song1) BOOST_MSM_EUML_STATE(( Song2_Entry,Song2_Exit ),Song2) BOOST_MSM_EUML_STATE(( Song3_Entry,Song3_Exit ),Song3) // Playing has a transition table BOOST_MSM_EUML_TRANSITION_TABLE(( // +------------------------------------------------------------------------------+ Song2 == Song1 + next_song / start_next_song, Song1 == Song2 + previous_song / start_prev_song, Song3 == Song2 + next_song / start_next_song, Song2 == Song3 + previous_song / start_prev_song // +------------------------------------------------------------------------------+ ),playing_transition_table ) BOOST_MSM_EUML_DECLARE_STATE_MACHINE( (playing_transition_table, //STT init_ << Song1, // Init State no_action, // entry no_action, // exit attributes_ << no_attributes_, //attributes configure_<< PlayingPaused << CDLoaded //flags ),Playing_) // choice of back-end typedef msm::back::state_machine<Playing_> Playing_type; Playing_type const Playing; // guard conditions BOOST_MSM_EUML_ACTION(good_disk_format) { template <class FSM,class EVT,class SourceState,class TargetState> bool operator()(EVT const& evt,FSM&,SourceState& ,TargetState& ) { // to test a guard condition, let's say we understand only CDs, not DVD if (evt.get_attribute(cd_type)!=DISK_CD) { std::cout << "wrong disk, sorry" << std::endl; // just for logging, does not block any transition return true; } std::cout << "good disk" << std::endl; return true; } }; // replaces the old transition table BOOST_MSM_EUML_TRANSITION_TABLE(( Playing == Stopped + play / start_playback , Playing == Paused + end_pause / resume_playback, // +------------------------------------------------------------------------------+ Empty == Open + open_close / close_drawer, // +------------------------------------------------------------------------------+ Open == Empty + open_close / open_drawer, Open == Paused + open_close / stop_and_open, Open == Stopped + open_close / open_drawer, Open == Playing + open_close / stop_and_open, // +------------------------------------------------------------------------------+ Paused == Playing + pause / pause_playback, // +------------------------------------------------------------------------------+ Stopped == Playing + stop / stop_playback, Stopped == Paused + stop / stop_playback, Stopped == Empty + cd_detected [good_disk_format&& (event_(cd_type)==Int_<DISK_CD>())] / (store_cd_info,process_(play)), Stopped == Stopped + stop, ErrorMode == AllOk + error_found / report_error, AllOk == ErrorMode+ end_error / report_end_error // +------------------------------------------------------------------------------+ ),transition_table) // create a state machine "on the fly" BOOST_MSM_EUML_DECLARE_STATE_MACHINE(( transition_table, //STT init_ << Empty<< AllOk, // Init State no_action, // Entry no_action, // Exit attributes_ << no_attributes_, // Attributes configure_ << no_configure_, // configuration Log_No_Transition // no_transition handler ), player_) //fsm name // choice of back-end typedef msm::back::state_machine<player_> player; // // Testing utilities. // static char const* const state_names[] = { "Stopped", "Paused", "Open", "Empty", "Playing","AllOk","ErrorMode" }; void pstate(player const& p) { // we have now several active states, which we show 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(); // tests some flags std::cout << "CDLoaded active:" << std::boolalpha << p.is_flag_active<BOOST_MSM_EUML_FLAG_NAME(CDLoaded)>() << std::endl; //=> false (no CD yet) // go to Open, call on_exit on Empty, then action, then on_entry on Open p.process_event(open_close); pstate(p); p.process_event(open_close); pstate(p); // will be rejected, wrong disk type p.process_event( cd_detected("louie, louie",DISK_DVD)); pstate(p); p.process_event( cd_detected("louie, louie",DISK_CD)); pstate(p); // 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 std::cout << "PlayingPaused active:" << std::boolalpha << p.is_flag_active<BOOST_MSM_EUML_FLAG_NAME(PlayingPaused)>() << std::endl;//=> true std::cout << "FirstSong active:" << std::boolalpha << p.is_flag_active<BOOST_MSM_EUML_FLAG_NAME(FirstSongPlaying)>() << std::endl;//=> true // make transition happen inside it. Player has no idea about this event but it's ok. p.process_event(next_song);pstate(p); //2nd song active p.process_event(next_song);pstate(p);//3rd song active p.process_event(previous_song);pstate(p);//2nd song active std::cout << "FirstSong active:" << std::boolalpha << p.is_flag_active<BOOST_MSM_EUML_FLAG_NAME(FirstSongPlaying)>() << std::endl;//=> false std::cout << "PlayingPaused active:" << std::boolalpha << p.is_flag_active<BOOST_MSM_EUML_FLAG_NAME(PlayingPaused)>() << std::endl;//=> true // at this point, Play is active p.process_event(pause); pstate(p); std::cout << "PlayingPaused active:" << std::boolalpha << p.is_flag_active<BOOST_MSM_EUML_FLAG_NAME(PlayingPaused)>() << std::endl;//=> true // go back to Playing p.process_event(end_pause); pstate(p); p.process_event(pause); pstate(p); p.process_event(stop); pstate(p); std::cout << "PlayingPaused active:" << std::boolalpha << p.is_flag_active<BOOST_MSM_EUML_FLAG_NAME(PlayingPaused)>() << std::endl;//=> false std::cout << "CDLoaded active:" << std::boolalpha << p.is_flag_active<BOOST_MSM_EUML_FLAG_NAME(CDLoaded)>() << std::endl;//=> true // by default, the flags are OR'ed but you can also use AND. Then the flag must be present in // all of the active states std::cout << "CDLoaded active with AND:" << std::boolalpha << p.is_flag_active<BOOST_MSM_EUML_FLAG_NAME(CDLoaded),player::Flag_AND>() << std::endl;//=> false // event leading to the same state // no action method called as none is defined in the transition table p.process_event(stop); pstate(p); // event leading to a terminal/interrupt state 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(play);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(play);pstate(p); } } int main() { test(); return 0; }