| // 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) |
| |
| // 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) |
| |
| // Concrete FSM implementation |
| // The list of FSM states |
| // state not needing any entry or exit |
| BOOST_MSM_EUML_STATE((),Paused) |
| |
| // it is also possible to define a state which you can implement normally |
| // just make it a state, as usual, and also a grammar terminal, euml_state |
| struct Empty_impl : public msm::front::state<> , public euml_state<Empty_impl> |
| { |
| // this allows us to add some functions |
| void activate_empty() {std::cout << "switching to Empty " << std::endl;} |
| // standard entry behavior |
| template <class Event,class FSM> |
| void on_entry(Event const& evt,FSM& fsm) |
| { |
| std::cout << "entering: Empty" << std::endl; |
| } |
| template <class Event,class FSM> |
| void on_exit(Event const& evt,FSM& fsm) |
| { |
| std::cout << "leaving: Empty" << std::endl; |
| } |
| }; |
| //instance for use in the transition table |
| Empty_impl const Empty; |
| |
| // create a functor and a eUML function for the activate_empty method from Entry |
| BOOST_MSM_EUML_METHOD(ActivateEmpty_ , activate_empty , activate_empty_ , void , void ) |
| |
| // define more states |
| BOOST_MSM_EUML_STATE(( Open_Entry,Open_Exit ),Open) |
| BOOST_MSM_EUML_STATE(( Stopped_Entry,Stopped_Exit ),Stopped) |
| BOOST_MSM_EUML_STATE(( Playing_Entry,Playing_Exit ),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,activate_empty_(target_)), |
| // +------------------------------------------------------------------------------+ |
| 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 |
| // +------------------------------------------------------------------------------+ |
| ),transition_table) |
| |
| // create a state machine "on the fly" |
| BOOST_MSM_EUML_DECLARE_STATE_MACHINE(( transition_table, //STT |
| init_ << Empty, // 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 |
| |
| // or simply, if no no_transition handler needed: |
| //BOOST_MSM_EUML_DECLARE_STATE_MACHINE(( transition_table, //STT |
| // Empty // Init State |
| // ),player_) |
| |
| // choice of back-end |
| typedef msm::back::state_machine<player_> player; |
| |
| // |
| // Testing utilities. |
| // |
| static char const* const state_names[] = { "Stopped", "Paused", "Open", "Empty", "Playing" }; |
| void pstate(player const& p) |
| { |
| std::cout << " -> " << state_names[p.current_state()[0]] << 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(); |
| // note that we write open_close and not open_close(), like usual. Both are possible with eUML, but |
| // you now have less to type. |
| // 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 |
| p.process_event(pause); pstate(p); |
| // go back to Playing |
| p.process_event(end_pause); pstate(p); |
| p.process_event(pause); pstate(p); |
| p.process_event(stop); pstate(p); |
| // event leading to the same state |
| // no action method called as none is defined in the transition table |
| p.process_event(stop); pstate(p); |
| // test call to no_transition |
| p.process_event(pause); pstate(p); |
| } |
| } |
| |
| int main() |
| { |
| test(); |
| return 0; |
| } |