[ceph.git] / ceph / src / boost / libs / msm / doc / HTML / examples / History.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>
// back-end
#include <boost/msm/back/state_machine.hpp>
//front-end
#include <boost/msm/front/state_machine_def.hpp>

namespace msm = boost::msm;
namespace mpl = boost::mpl;

namespace  
{
    // events
    struct play {};
    struct end_pause {};
    struct stop {};
    struct pause {};
    struct open_close {};
    struct NextSong {};
    struct PreviousSong {};

    // A "complicated" event type that carries some data.
    struct cd_detected
    {
        cd_detected(std::string name)
            : name(name)
        {}

        std::string name;
    };

    // front-end: define the FSM structure 
    struct player_ : public msm::front::state_machine_def<player_>
    {
        // The list of FSM states
        struct Empty : public msm::front::state<> 
        {
            // every (optional) entry/exit methods get the event passed
            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;}
        };
        struct Open : public msm::front::state<> 
        { 
            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;}
        };

        struct Stopped : public msm::front::state<> 
        { 
            // when stopped, the CD is loaded
            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;}
        };

        struct Playing_ : public msm::front::state_machine_def<Playing_>
        {
            // when playing, the CD is loaded and we are in either pause or playing (duh)
            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;}

            // The list of FSM states
            struct Song1 : public msm::front::state<>
            {
                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;}
            };
            struct Song2 : public msm::front::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<>
            { 
                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;
            }

        };
        // back-end
        // 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
        typedef msm::back::state_machine<Playing_,msm::back::ShallowHistory<mpl::vector<end_pause> > > Playing;

        // state not defining any entry or exit
        struct Paused : public msm::front::state<>
        {
            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 initial state of the player SM. Must be defined
        typedef Empty initial_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& cd) {std::cout << "player::store_cd_info\n";}
        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";}
        // 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                          >
            //    +---------+-------------+---------+---------------------+----------------------+
        > {};

        // 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);
        p.process_event(cd_detected("louie, louie"));
        p.process_event(play());

        // at this point, Play is active 
        // make transition happen inside it. Player has no idea about this event but it's ok.
        p.process_event(NextSong());pstate(p); //2nd song active
        p.process_event(NextSong());pstate(p);//3rd song active
        p.process_event(PreviousSong());pstate(p);//2nd song active

        p.process_event(pause()); pstate(p);
        // go back to Playing
        // as you see, remembers the original state as end_pause is an history trigger
        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
        p.process_event(stop());  pstate(p);
        // play does not trigger shallow history => start back from 1st song
        p.process_event(play());  pstate(p);
    }
}

int main()
{
    test();
    return 0;
}
Commit	Line	Data
7c673cae FG	1	// Copyright 2010 Christophe Henry
	2	// henry UNDERSCORE christophe AT hotmail DOT com
	3	// This is an extended version of the state machine available in the boost::mpl library
	4	// Distributed under the same license as the original.
	5	// Copyright for the original version:
	6	// Copyright 2005 David Abrahams and Aleksey Gurtovoy. Distributed
	7	// under the Boost Software License, Version 1.0. (See accompanying
	8	// file LICENSE_1_0.txt or copy at
	9	// http://www.boost.org/LICENSE_1_0.txt)
	10
	11	#include <iostream>
	12	// back-end
	13	#include <boost/msm/back/state_machine.hpp>
	14	//front-end
	15	#include <boost/msm/front/state_machine_def.hpp>
	16
	17	namespace msm = boost::msm;
	18	namespace mpl = boost::mpl;
	19
	20	namespace
	21	{
	22	// events
	23	struct play {};
	24	struct end_pause {};
	25	struct stop {};
	26	struct pause {};
	27	struct open_close {};
	28	struct NextSong {};
	29	struct PreviousSong {};
	30
	31	// A "complicated" event type that carries some data.
	32	struct cd_detected
	33	{
	34	cd_detected(std::string name)
	35	: name(name)
	36	{}
	37
	38	std::string name;
	39	};
	40
	41	// front-end: define the FSM structure
	42	struct player_ : public msm::front::state_machine_def<player_>
	43	{
	44	// The list of FSM states
	45	struct Empty : public msm::front::state<>
	46	{
	47	// every (optional) entry/exit methods get the event passed
	48	template <class Event,class FSM>
	49	void on_entry(Event const&,FSM& ) {std::cout << "entering: Empty" << std::endl;}
	50	template <class Event,class FSM>
	51	void on_exit(Event const&,FSM& ) {std::cout << "leaving: Empty" << std::endl;}
	52	};
	53	struct Open : public msm::front::state<>
	54	{
	55	template <class Event,class FSM>
	56	void on_entry(Event const&,FSM& ) {std::cout << "entering: Open" << std::endl;}
	57	template <class Event,class FSM>
	58	void on_exit(Event const&,FSM& ) {std::cout << "leaving: Open" << std::endl;}
	59	};
	60
	61	struct Stopped : public msm::front::state<>
	62	{
	63	// when stopped, the CD is loaded
	64	template <class Event,class FSM>
65	void on_entry(Event const&,FSM& ) {std::cout << "entering: Stopped" << std::endl;}
66	template <class Event,class FSM>
67	void on_exit(Event const&,FSM& ) {std::cout << "leaving: Stopped" << std::endl;}
68	};
69
70	struct Playing_ : public msm::front::state_machine_def<Playing_>
71	{
72	// when playing, the CD is loaded and we are in either pause or playing (duh)
73	template <class Event,class FSM>
74	void on_entry(Event const&,FSM& ) {std::cout << "entering: Playing" << std::endl;}
75	template <class Event,class FSM>
76	void on_exit(Event const&,FSM& ) {std::cout << "leaving: Playing" << std::endl;}
77
78	// The list of FSM states
79	struct Song1 : public msm::front::state<>
80	{
81	template <class Event,class FSM>
82	void on_entry(Event const&,FSM& ) {std::cout << "starting: First song" << std::endl;}
83	template <class Event,class FSM>
84	void on_exit(Event const&,FSM& ) {std::cout << "finishing: First Song" << std::endl;}
85	};
86	struct Song2 : public msm::front::state<>
87	{
88	template <class Event,class FSM>
89	void on_entry(Event const&,FSM& ) {std::cout << "starting: Second song" << std::endl;}
90	template <class Event,class FSM>
91	void on_exit(Event const&,FSM& ) {std::cout << "finishing: Second Song" << std::endl;}
92	};
93	struct Song3 : public msm::front::state<>
94	{
95	template <class Event,class FSM>
96	void on_entry(Event const&,FSM& ) {std::cout << "starting: Third song" << std::endl;}
97	template <class Event,class FSM>
98	void on_exit(Event const&,FSM& ) {std::cout << "finishing: Third Song" << std::endl;}
99	};
100	// the initial state. Must be defined
101	typedef Song1 initial_state;
102	// transition actions
103	void start_next_song(NextSong const&) { std::cout << "Playing::start_next_song\n"; }
104	void start_prev_song(PreviousSong const&) { std::cout << "Playing::start_prev_song\n"; }
105	// guard conditions
106
107	typedef Playing_ pl; // makes transition table cleaner
108	// Transition table for Playing
109	struct transition_table : mpl::vector4<
110	// Start Event Next Action Guard
111	// +---------+-------------+---------+---------------------+----------------------+
112	a_row < Song1 , NextSong , Song2 , &pl::start_next_song >,
113	a_row < Song2 , PreviousSong, Song1 , &pl::start_prev_song >,
114	a_row < Song2 , NextSong , Song3 , &pl::start_next_song >,
115	a_row < Song3 , PreviousSong, Song2 , &pl::start_prev_song >
116	// +---------+-------------+---------+---------------------+----------------------+
117	> {};
118	// Replaces the default no-transition response.
119	template <class FSM,class Event>
120	void no_transition(Event const& e, FSM&,int state)
121	{
122	std::cout << "no transition from state " << state
123	<< " on event " << typeid(e).name() << std::endl;
124	}
125
126	};
127	// back-end
128	// demonstrates Shallow History: if the state gets activated with end_pause
129	// then it will remember the last active state and reactivate it
130	// also possible: AlwaysHistory, the last active state will always be reactivated
131	// or NoHistory, always restart from the initial state
132	typedef msm::back::state_machine<Playing_,msm::back::ShallowHistory<mpl::vector<end_pause> > > Playing;
133
134	// state not defining any entry or exit
135	struct Paused : public msm::front::state<>
136	{
137	template <class Event,class FSM>
138	void on_entry(Event const&,FSM& ) {std::cout << "entering: Paused" << std::endl;}
139	template <class Event,class FSM>
140	void on_exit(Event const&,FSM& ) {std::cout << "leaving: Paused" << std::endl;}
141	};
142
143	// the initial state of the player SM. Must be defined
144	typedef Empty initial_state;
145
146	// transition actions
147	void start_playback(play const&) { std::cout << "player::start_playback\n"; }
148	void open_drawer(open_close const&) { std::cout << "player::open_drawer\n"; }
149	void close_drawer(open_close const&) { std::cout << "player::close_drawer\n"; }
150	void store_cd_info(cd_detected const& cd) {std::cout << "player::store_cd_info\n";}
151	void stop_playback(stop const&) { std::cout << "player::stop_playback\n"; }
152	void pause_playback(pause const&) { std::cout << "player::pause_playback\n"; }
153	void resume_playback(end_pause const&) { std::cout << "player::resume_playback\n"; }
154	void stop_and_open(open_close const&) { std::cout << "player::stop_and_open\n"; }
155	void stopped_again(stop const&){std::cout << "player::stopped_again\n";}
156	// guard conditions
157
158	typedef player_ p; // makes transition table cleaner
159
160	// Transition table for player
161	struct transition_table : mpl::vector<
162	// Start Event Next Action Guard
163	// +---------+-------------+---------+---------------------+----------------------+
164	a_row < Stopped , play , Playing , &p::start_playback >,
165	a_row < Stopped , open_close , Open , &p::open_drawer >,
166	a_row < Stopped , stop , Stopped , &p::stopped_again >,
167	// +---------+-------------+---------+---------------------+----------------------+
168	a_row < Open , open_close , Empty , &p::close_drawer >,
169	// +---------+-------------+---------+---------------------+----------------------+
170	a_row < Empty , open_close , Open , &p::open_drawer >,
171	a_row < Empty , cd_detected , Stopped , &p::store_cd_info >,
172	// +---------+-------------+---------+---------------------+----------------------+
173	a_row < Playing , stop , Stopped , &p::stop_playback >,
174	a_row < Playing , pause , Paused , &p::pause_playback >,
175	a_row < Playing , open_close , Open , &p::stop_and_open >,
176	// +---------+-------------+---------+---------------------+----------------------+
177	a_row < Paused , end_pause , Playing , &p::resume_playback >,
178	a_row < Paused , stop , Stopped , &p::stop_playback >,
179	a_row < Paused , open_close , Open , &p::stop_and_open >
180	// +---------+-------------+---------+---------------------+----------------------+
181	> {};
182
183	// Replaces the default no-transition response.
184	template <class FSM,class Event>
185	void no_transition(Event const& e, FSM&,int state)
186	{
187	std::cout << "no transition from state " << state
188	<< " on event " << typeid(e).name() << std::endl;
189	}
190
191	};
192	// Pick a back-end
193	typedef msm::back::state_machine<player_> player;
194
195	//
196	// Testing utilities.
197	//
198	static char const* const state_names[] = { "Stopped", "Open", "Empty", "Playing", "Paused" };
199
200	void pstate(player const& p)
201	{
202	std::cout << " -> " << state_names[p.current_state()[0]] << std::endl;
203	}
204
205	void test()
206	{
207	player p;
208
209	// needed to start the highest-level SM. This will call on_entry and mark the start of the SM
210	p.start();
211	// go to Open, call on_exit on Empty, then action, then on_entry on Open
212	p.process_event(open_close()); pstate(p);
213	p.process_event(open_close()); pstate(p);
214	p.process_event(cd_detected("louie, louie"));
215	p.process_event(play());
216
217	// at this point, Play is active
218	// make transition happen inside it. Player has no idea about this event but it's ok.
219	p.process_event(NextSong());pstate(p); //2nd song active
220	p.process_event(NextSong());pstate(p);//3rd song active
221	p.process_event(PreviousSong());pstate(p);//2nd song active
222
223	p.process_event(pause()); pstate(p);
224	// go back to Playing
225	// as you see, remembers the original state as end_pause is an history trigger
226	p.process_event(end_pause()); pstate(p);
227	p.process_event(pause()); pstate(p);
228	p.process_event(stop()); pstate(p);
229	// event leading to the same state
230	p.process_event(stop()); pstate(p);
231	// play does not trigger shallow history => start back from 1st song
232	p.process_event(play()); pstate(p);
233	}
234	}
235
236	int main()
237	{
238	test();
239	return 0;
240	}