| // 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/phoenix/phoenix.hpp> |
| |
| // add phoenix support in eUML |
| #define BOOST_MSM_EUML_PHOENIX_SUPPORT |
| #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; |
| using namespace boost::phoenix; |
| |
| // entry/exit/action/guard logging functors |
| #include "logging_functors.h" |
| |
| namespace // Concrete FSM implementation |
| { |
| // events |
| BOOST_MSM_EUML_EVENT(end_pause) |
| BOOST_MSM_EUML_EVENT(stop) |
| BOOST_MSM_EUML_EVENT(pause) |
| BOOST_MSM_EUML_EVENT(open_close) |
| struct play_event : boost::msm::front::euml::euml_event<play_event> |
| { |
| }; |
| play_event play; |
| |
| enum DiskTypeEnum |
| { |
| DISK_CD=0, |
| DISK_DVD=1 |
| }; |
| // A "complicated" event type that carries some data. |
| struct cd_detected_event : boost::msm::front::euml::euml_event<cd_detected_event> |
| { |
| cd_detected_event(){} |
| cd_detected_event(std::string const& name,DiskTypeEnum disk):cd_name(name),cd_type(disk){} |
| std::string cd_name; |
| DiskTypeEnum cd_type; |
| }; |
| // define an instance for a nicer transition table |
| cd_detected_event cd_detected; |
| |
| // Concrete FSM implementation |
| // The list of FSM states |
| // state not needing any entry or exit |
| BOOST_MSM_EUML_STATE((),Paused) |
| |
| // states with standard eUML actions |
| BOOST_MSM_EUML_STATE(( Stopped_Entry,Stopped_Exit ),Stopped) |
| BOOST_MSM_EUML_STATE(( Playing_Entry,Playing_Exit ),Playing) |
| |
| // a "standard" msm state |
| struct Empty_impl : public msm::front::state<> , public euml_state<Empty_impl> |
| { |
| // this allows us to add some functions |
| void foo() {std::cout << "Empty::foo " << 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; |
| |
| // entry and exit actions as phoenix functions |
| struct open_entry_impl |
| { |
| typedef void result_type; |
| void operator()() |
| { |
| cout << "entering: Open" << endl; |
| } |
| }; |
| boost::phoenix::function<open_entry_impl> open_entry; |
| struct open_exit_impl |
| { |
| typedef void result_type; |
| void operator()() |
| { |
| cout << "leaving: Open" << endl; |
| } |
| }; |
| boost::phoenix::function<open_exit_impl> open_exit; |
| |
| // a state using phoenix for entry/exit actions |
| BOOST_MSM_EUML_STATE(( open_entry(),open_exit() ),Open) |
| |
| // actions and guards using boost::phoenix |
| struct start_playback_impl |
| { |
| typedef void result_type; |
| void operator()() |
| { |
| cout << "calling: start_playback" << endl; |
| } |
| }; |
| boost::phoenix::function<start_playback_impl> start_playback; |
| |
| // a guard taking the event as argument |
| struct good_disk_format_impl |
| { |
| typedef bool result_type; |
| |
| template <class Event> |
| bool operator()(Event const& evt) |
| { |
| // to test a guard condition, let's say we understand only CDs, not DVD |
| if (evt.cd_type!=DISK_CD) |
| { |
| std::cout << "wrong disk, sorry" << std::endl; |
| return false; |
| } |
| std::cout << "good disk" << std::endl; |
| return true; |
| } |
| }; |
| boost::phoenix::function<good_disk_format_impl> good_disk_format; |
| |
| // a simple action |
| struct store_cd_info_impl |
| { |
| typedef void result_type; |
| void operator()() |
| { |
| cout << "calling: store_cd_info" << endl; |
| } |
| }; |
| boost::phoenix::function<store_cd_info_impl> store_cd_info; |
| |
| // an action taking the fsm as argument and sending it a new event |
| struct process_play_impl |
| { |
| typedef void result_type; |
| |
| template <class Fsm> |
| void operator()(Fsm& fsm) |
| { |
| cout << "queuing a play event" << endl; |
| fsm.process_event(play); |
| } |
| }; |
| // it is also possible to use BOOST_PHOENIX_ADAPT_CALLABLE to avoid defining a global variable |
| BOOST_PHOENIX_ADAPT_CALLABLE(process_play, process_play_impl, 1) |
| |
| |
| // transition table. Actions and guards are written as phoenix functions |
| BOOST_MSM_EUML_TRANSITION_TABLE(( |
| //an action without arguments |
| Playing == Stopped + play / start_playback() , |
| Playing == Paused + end_pause , |
| // +------------------------------------------------------------------------------+ |
| Empty == Open + open_close , |
| // +------------------------------------------------------------------------------+ |
| Open == Empty + open_close , |
| Open == Paused + open_close , |
| Open == Stopped + open_close , |
| Open == Playing + open_close , |
| // +------------------------------------------------------------------------------+ |
| Paused == Playing + pause , |
| // +------------------------------------------------------------------------------+ |
| Stopped == Playing + stop , |
| Stopped == Paused + stop , |
| // a guard taking the event as argument |
| // and an action made of a phoenix expression of 2 actions |
| // _event is a placeholder for the current event |
| // _fsm is a placeholder for the current state machine |
| Stopped == Empty + cd_detected [good_disk_format(_event)] |
| / (store_cd_info(),process_play(_fsm)), |
| 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(); |
| // 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_event("louie, louie",DISK_DVD)); pstate(p); |
| p.process_event( |
| cd_detected_event("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; |
| } |
| |