| // 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> |
| // back-end |
| #include <boost/msm/back/state_machine.hpp> |
| //front-end |
| #include <boost/msm/front/state_machine_def.hpp> |
| // functors |
| #include <boost/msm/front/functor_row.hpp> |
| #include <boost/msm/front/euml/common.hpp> |
| // for And_ operator |
| #include <boost/msm/front/euml/operator.hpp> |
| // for func_state and func_state_machine |
| #include <boost/msm/front/euml/state_grammar.hpp> |
| |
| using namespace std; |
| namespace msm = boost::msm; |
| namespace mpl = boost::mpl; |
| using namespace msm::front; |
| // for And_ operator |
| using namespace msm::front::euml; |
| |
| namespace // Concrete FSM implementation |
| { |
| // events |
| struct play {}; |
| struct end_pause {}; |
| struct stop {}; |
| struct pause {}; |
| struct open_close {}; |
| |
| // A "complicated" event type that carries some data. |
| enum DiskTypeEnum |
| { |
| DISK_CD=0, |
| DISK_DVD=1 |
| }; |
| struct cd_detected |
| { |
| cd_detected(std::string name, DiskTypeEnum diskType) |
| : name(name), |
| disc_type(diskType) |
| {} |
| |
| std::string name; |
| DiskTypeEnum disc_type; |
| }; |
| |
| // front-end: define the FSM structure |
| struct player_ : public msm::front::state_machine_def<player_> |
| { |
| // The list of FSM states |
| // entry and exit functors for Empty |
| struct Empty_Entry |
| { |
| template <class Event,class FSM,class STATE> |
| void operator()(Event const&,FSM&,STATE& ) |
| { |
| std::cout << "entering: Empty" << std::endl; |
| } |
| }; |
| struct Empty_Exit |
| { |
| template <class Event,class FSM,class STATE> |
| void operator()(Event const&,FSM&,STATE& ) |
| { |
| std::cout << "leaving: Empty" << std::endl; |
| } |
| }; |
| // definition of Empty |
| struct Empty_tag {}; |
| typedef msm::front::euml::func_state<Empty_tag,Empty_Entry,Empty_Exit> Empty; |
| |
| struct Open_Entry |
| { |
| template <class Event,class FSM,class STATE> |
| void operator()(Event const&,FSM&,STATE& ) |
| { |
| std::cout << "entering: Open" << std::endl; |
| } |
| }; |
| struct Open_Exit |
| { |
| template <class Event,class FSM,class STATE> |
| void operator()(Event const&,FSM&,STATE& ) |
| { |
| std::cout << "leaving: Open" << std::endl; |
| } |
| }; |
| struct Open_tag {}; |
| typedef msm::front::euml::func_state<Open_tag,Open_Entry,Open_Exit> Open; |
| |
| // states without entry/exit actions (can be declared as functor state, just without functors ;-) ) |
| struct Stopped_tag {}; |
| typedef msm::front::euml::func_state<Stopped_tag> Stopped; |
| |
| struct Playing_tag {}; |
| typedef msm::front::euml::func_state<Playing_tag> Playing; |
| |
| // state not defining any entry or exit (declared as simple state. Equivalent) |
| struct Paused : public msm::front::state<> |
| { |
| }; |
| |
| // the initial state of the player SM. Must be defined |
| typedef Empty initial_state; |
| |
| // transition actions |
| // as the functors are generic on events, fsm and source/target state, |
| // you can reuse them in another machine if you wish |
| struct TestFct |
| { |
| template <class EVT,class FSM,class SourceState,class TargetState> |
| void operator()(EVT const&, FSM&,SourceState& ,TargetState& ) |
| { |
| cout << "transition with event:" << typeid(EVT).name() << endl; |
| } |
| }; |
| struct start_playback |
| { |
| template <class EVT,class FSM,class SourceState,class TargetState> |
| void operator()(EVT const& ,FSM& ,SourceState& ,TargetState& ) |
| { |
| cout << "player::start_playback" << endl; |
| } |
| }; |
| struct open_drawer |
| { |
| template <class EVT,class FSM,class SourceState,class TargetState> |
| void operator()(EVT const& ,FSM& ,SourceState& ,TargetState& ) |
| { |
| cout << "player::open_drawer" << endl; |
| } |
| }; |
| struct close_drawer |
| { |
| template <class EVT,class FSM,class SourceState,class TargetState> |
| void operator()(EVT const& ,FSM& ,SourceState& ,TargetState& ) |
| { |
| cout << "player::close_drawer" << endl; |
| } |
| }; |
| struct store_cd_info |
| { |
| template <class EVT,class FSM,class SourceState,class TargetState> |
| void operator()(EVT const&,FSM& fsm ,SourceState& ,TargetState& ) |
| { |
| cout << "player::store_cd_info" << endl; |
| fsm.process_event(play()); |
| } |
| }; |
| struct stop_playback |
| { |
| template <class EVT,class FSM,class SourceState,class TargetState> |
| void operator()(EVT const& ,FSM& ,SourceState& ,TargetState& ) |
| { |
| cout << "player::stop_playback" << endl; |
| } |
| }; |
| struct pause_playback |
| { |
| template <class EVT,class FSM,class SourceState,class TargetState> |
| void operator()(EVT const& ,FSM& ,SourceState& ,TargetState& ) |
| { |
| cout << "player::pause_playback" << endl; |
| } |
| }; |
| struct resume_playback |
| { |
| template <class EVT,class FSM,class SourceState,class TargetState> |
| void operator()(EVT const& ,FSM& ,SourceState& ,TargetState& ) |
| { |
| cout << "player::resume_playback" << endl; |
| } |
| }; |
| struct stop_and_open |
| { |
| template <class EVT,class FSM,class SourceState,class TargetState> |
| void operator()(EVT const& ,FSM& ,SourceState& ,TargetState& ) |
| { |
| cout << "player::stop_and_open" << endl; |
| } |
| }; |
| struct stopped_again |
| { |
| template <class EVT,class FSM,class SourceState,class TargetState> |
| void operator()(EVT const& ,FSM& ,SourceState& ,TargetState& ) |
| { |
| cout << "player::stopped_again" << endl; |
| } |
| }; |
| // guard conditions |
| struct DummyGuard |
| { |
| template <class EVT,class FSM,class SourceState,class TargetState> |
| bool operator()(EVT const& evt,FSM& fsm,SourceState& src,TargetState& tgt) |
| { |
| return true; |
| } |
| }; |
| struct good_disk_format |
| { |
| template <class EVT,class FSM,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.disc_type != DISK_CD) |
| { |
| std::cout << "wrong disk, sorry" << std::endl; |
| return false; |
| } |
| return true; |
| } |
| }; |
| struct always_true |
| { |
| template <class EVT,class FSM,class SourceState,class TargetState> |
| bool operator()(EVT const& evt ,FSM&,SourceState& ,TargetState& ) |
| { |
| return true; |
| } |
| }; |
| // we want to define one row with the classic look. |
| bool auto_start(cd_detected const& evt) |
| { |
| return false; |
| } |
| |
| typedef player_ p; // makes transition table cleaner |
| |
| // Transition table for player |
| struct transition_table : mpl::vector< |
| // Start Event Next Action Guard |
| // +---------+-------------+---------+---------------------------+----------------------+ |
| Row < Stopped , play , Playing , ActionSequence_ |
| <mpl::vector< |
| TestFct,start_playback> > |
| , DummyGuard >, |
| Row < Stopped , open_close , Open , open_drawer , none >, |
| Row < Stopped , stop , Stopped , none , none >, |
| // +---------+-------------+---------+---------------------------+----------------------+ |
| Row < Open , open_close , Empty , close_drawer , none >, |
| // +---------+-------------+---------+---------------------------+----------------------+ |
| Row < Empty , open_close , Open , open_drawer , none >, |
| Row < Empty , cd_detected , Stopped , store_cd_info , And_<good_disk_format, |
| always_true> >, |
| // we here also mix with some "classical row" |
| g_row < Empty , cd_detected , Playing , &p::auto_start >, |
| // +---------+-------------+---------+---------------------------+----------------------+ |
| Row < Playing , stop , Stopped , stop_playback , none >, |
| Row < Playing , pause , Paused , pause_playback , none >, |
| Row < Playing , open_close , Open , stop_and_open , none >, |
| // +---------+-------------+---------+---------------------------+----------------------+ |
| Row < Paused , end_pause , Playing , resume_playback , none >, |
| Row < Paused , stop , Stopped , stop_playback , none >, |
| Row < Paused , open_close , Open , stop_and_open , none > |
| // +---------+-------------+---------+---------------------------+----------------------+ |
| > {}; |
| // 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; |
| } |
| }; |
| // Pick a back-end |
| typedef msm::back::state_machine<player_> player; |
| |
| // |
| // Testing utilities. |
| // |
| static char const* const state_names[] = { "Stopped", "Open", "Empty", "Playing", "Paused" }; |
| 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(); |
| // 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 it is not present in the transition table |
| p.process_event(stop()); pstate(p); |
| } |
| } |
| |
| int main() |
| { |
| test(); |
| return 0; |
| } |
