[ceph.git] / ceph / src / boost / libs / msm / doc / PDF / examples / Serialize.cpp

#include <iostream>
// back-end
#include <boost/msm/back/state_machine.hpp>
//front-end
#include <boost/msm/front/state_machine_def.hpp>

// include headers that implement a archive in simple text format
#include <boost/archive/text_oarchive.hpp>
#include <boost/archive/text_iarchive.hpp>
#include <boost/serialization/tracking.hpp>

#include <fstream>


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


namespace
{
    // 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_>
    {
        //we might want to serialize some data contained by the front-end
        int front_end_data;
        player_():front_end_data(0){}
        // to achieve this, ask for it
        typedef int do_serialize;
        // and provide a serialize
        template<class Archive>
        void serialize(Archive & ar, const unsigned int )
        {
            ar & front_end_data;
        }
        // The list of FSM states
        struct Empty : public msm::front::state<> 
        {
            // we want Empty to be serialized
            typedef int do_serialize;
            template<class Archive>
            void serialize(Archive & ar, const unsigned int )
            {
                ar & some_dummy_data;
            }
            Empty():some_dummy_data(0){}
            // 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;}
            int some_dummy_data;
        };
        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;}
        };

        // sm_ptr still supported but deprecated as functors are a much better way to do the same thing
        struct Stopped : public msm::front::state<msm::front::default_base_state,msm::front::sm_ptr> 
        {	 
            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;}
            void set_sm_ptr(player_* pl)
            {
                m_player=pl;
            }
            player_* m_player;
        };

        struct Playing : public msm::front::state<>
        {
            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;}
        };

        // state not defining any entry or exit
        struct Paused : public msm::front::state<>
        {
        };

        // 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&) { 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
        bool good_disk_format(cd_detected const& evt)
        {
            // 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;
        }
        // used to show a transition conflict. This guard will simply deactivate one transition and thus
        // solve the conflict
        bool auto_start(cd_detected const&)
        {
            return false;
        }

        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                            >,
           _row < Stopped , stop        , Stopped                                              >,
            //  +---------+-------------+---------+---------------------+----------------------+
          a_row < Open    , open_close  , Empty   , &p::close_drawer                           >,
            //  +---------+-------------+---------+---------------------+----------------------+
          a_row < Empty   , open_close  , Open    , &p::open_drawer                            >,
            row < Empty   , cd_detected , Stopped , &p::store_cd_info   ,&p::good_disk_format  >,
            row < Empty   , cd_detected , Playing , &p::store_cd_info   ,&p::auto_start        >,
            //  +---------+-------------+---------+---------------------+----------------------+
          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(); 
        p.get_state<player_::Empty&>().some_dummy_data=3;
        p.front_end_data=4;

        // go to Open, call on_exit on Empty, then action, then on_entry on Open
        p.process_event(open_close()); pstate(p);

        std::ofstream ofs("fsm.txt");
        // save fsm to archive (current state is Open)
        {
            boost::archive::text_oarchive oa(ofs);
            // write class instance to archive
            oa << p;
        }
        // reload fsm in state Open
        player p2;
        {
            // create and open an archive for input
            std::ifstream ifs("fsm.txt");
            boost::archive::text_iarchive ia(ifs);
            // read class state from archive
            ia >> p2;
        }
        // we now use p2 as it was loaded
        // check that we kept Empty's data value
        std::cout << "Empty's data should be 3:" << p2.get_state<player_::Empty&>().some_dummy_data << std::endl;
        std::cout << "front-end data should be 4:" << p2.front_end_data << std::endl;

        p2.process_event(open_close()); pstate(p2);
        // will be rejected, wrong disk type
        p2.process_event(
            cd_detected("louie, louie",DISK_DVD)); pstate(p2);
        p2.process_event(
            cd_detected("louie, louie",DISK_CD)); pstate(p2);
		p2.process_event(play());

        // at this point, Play is active      
        p2.process_event(pause()); pstate(p2);
        // go back to Playing
        p2.process_event(end_pause());  pstate(p2);
        p2.process_event(pause()); pstate(p2);
        p2.process_event(stop());  pstate(p2);
        // event leading to the same state
        // no action method called as it is not present in the transition table
        p2.process_event(stop());  pstate(p2);
    }
}
// eliminate object tracking (even if serialized through a pointer)
// at the risk of a programming error creating duplicate objects.
// this is to get rid of warning because p is not const
BOOST_CLASS_TRACKING(player, boost::serialization::track_never)

int main()
{
    test();
    return 0;
}
Commit	Line	Data
7c673cae FG	1	#include <iostream>
	2	// back-end
	3	#include <boost/msm/back/state_machine.hpp>
	4	//front-end
	5	#include <boost/msm/front/state_machine_def.hpp>
	6
	7	// include headers that implement a archive in simple text format
	8	#include <boost/archive/text_oarchive.hpp>
	9	#include <boost/archive/text_iarchive.hpp>
	10	#include <boost/serialization/tracking.hpp>
	11
	12	#include <fstream>
	13
	14
	15	namespace msm = boost::msm;
	16	namespace mpl = boost::mpl;
	17
	18
	19	namespace
	20	{
	21	// events
	22	struct play {};
	23	struct end_pause {};
	24	struct stop {};
	25	struct pause {};
	26	struct open_close {};
	27
	28	// A "complicated" event type that carries some data.
	29	enum DiskTypeEnum
	30	{
	31	DISK_CD=0,
	32	DISK_DVD=1
	33	};
	34	struct cd_detected
	35	{
	36	cd_detected(std::string name, DiskTypeEnum diskType)
	37	: name(name),
	38	disc_type(diskType)
	39	{}
	40
	41	std::string name;
	42	DiskTypeEnum disc_type;
	43	};
	44
	45	// front-end: define the FSM structure
	46	struct player_ : public msm::front::state_machine_def<player_>
	47	{
	48	//we might want to serialize some data contained by the front-end
	49	int front_end_data;
	50	player_():front_end_data(0){}
	51	// to achieve this, ask for it
	52	typedef int do_serialize;
	53	// and provide a serialize
	54	template<class Archive>
	55	void serialize(Archive & ar, const unsigned int )
	56	{
	57	ar & front_end_data;
	58	}
	59	// The list of FSM states
	60	struct Empty : public msm::front::state<>
	61	{
	62	// we want Empty to be serialized
	63	typedef int do_serialize;
	64	template<class Archive>
65	void serialize(Archive & ar, const unsigned int )
66	{
67	ar & some_dummy_data;
68	}
69	Empty():some_dummy_data(0){}
70	// every (optional) entry/exit methods get the event passed.
71	template <class Event,class FSM>
72	void on_entry(Event const&,FSM& ) {std::cout << "entering: Empty" << std::endl;}
73	template <class Event,class FSM>
74	void on_exit(Event const&,FSM& ) {std::cout << "leaving: Empty" << std::endl;}
75	int some_dummy_data;
76	};
77	struct Open : public msm::front::state<>
78	{
79	template <class Event,class FSM>
80	void on_entry(Event const& ,FSM&) {std::cout << "entering: Open" << std::endl;}
81	template <class Event,class FSM>
82	void on_exit(Event const&,FSM& ) {std::cout << "leaving: Open" << std::endl;}
83	};
84
85	// sm_ptr still supported but deprecated as functors are a much better way to do the same thing
86	struct Stopped : public msm::front::state<msm::front::default_base_state,msm::front::sm_ptr>
87	{
88	template <class Event,class FSM>
89	void on_entry(Event const& ,FSM&) {std::cout << "entering: Stopped" << std::endl;}
90	template <class Event,class FSM>
91	void on_exit(Event const&,FSM& ) {std::cout << "leaving: Stopped" << std::endl;}
92	void set_sm_ptr(player_* pl)
93	{
94	m_player=pl;
95	}
96	player_* m_player;
97	};
98
99	struct Playing : public msm::front::state<>
100	{
101	template <class Event,class FSM>
102	void on_entry(Event const&,FSM& ) {std::cout << "entering: Playing" << std::endl;}
103	template <class Event,class FSM>
104	void on_exit(Event const&,FSM& ) {std::cout << "leaving: Playing" << std::endl;}
105	};
106
107	// state not defining any entry or exit
108	struct Paused : public msm::front::state<>
109	{
110	};
111
112	// the initial state of the player SM. Must be defined
113	typedef Empty initial_state;
114
115	// transition actions
116	void start_playback(play const&) { std::cout << "player::start_playback\n"; }
117	void open_drawer(open_close const&) { std::cout << "player::open_drawer\n"; }
118	void close_drawer(open_close const&) { std::cout << "player::close_drawer\n"; }
119	void store_cd_info(cd_detected const&) { std::cout << "player::store_cd_info\n"; }
120	void stop_playback(stop const&) { std::cout << "player::stop_playback\n"; }
121	void pause_playback(pause const&) { std::cout << "player::pause_playback\n"; }
122	void resume_playback(end_pause const&) { std::cout << "player::resume_playback\n"; }
123	void stop_and_open(open_close const&) { std::cout << "player::stop_and_open\n"; }
124	void stopped_again(stop const&) {std::cout << "player::stopped_again\n";}
125	// guard conditions
126	bool good_disk_format(cd_detected const& evt)
127	{
128	// to test a guard condition, let's say we understand only CDs, not DVD
129	if (evt.disc_type != DISK_CD)
130	{
131	std::cout << "wrong disk, sorry" << std::endl;
132	return false;
133	}
134	return true;
135	}
136	// used to show a transition conflict. This guard will simply deactivate one transition and thus
137	// solve the conflict
138	bool auto_start(cd_detected const&)
139	{
140	return false;
141	}
142
143	typedef player_ p; // makes transition table cleaner
144
145	// Transition table for player
146	struct transition_table : mpl::vector<
147	// Start Event Next Action Guard
148	// +---------+-------------+---------+---------------------+----------------------+
149	a_row < Stopped , play , Playing , &p::start_playback >,
150	a_row < Stopped , open_close , Open , &p::open_drawer >,
151	_row < Stopped , stop , Stopped >,
152	// +---------+-------------+---------+---------------------+----------------------+
153	a_row < Open , open_close , Empty , &p::close_drawer >,
154	// +---------+-------------+---------+---------------------+----------------------+
155	a_row < Empty , open_close , Open , &p::open_drawer >,
156	row < Empty , cd_detected , Stopped , &p::store_cd_info ,&p::good_disk_format >,
157	row < Empty , cd_detected , Playing , &p::store_cd_info ,&p::auto_start >,
158	// +---------+-------------+---------+---------------------+----------------------+
159	a_row < Playing , stop , Stopped , &p::stop_playback >,
160	a_row < Playing , pause , Paused , &p::pause_playback >,
161	a_row < Playing , open_close , Open , &p::stop_and_open >,
162	// +---------+-------------+---------+---------------------+----------------------+
163	a_row < Paused , end_pause , Playing , &p::resume_playback >,
164	a_row < Paused , stop , Stopped , &p::stop_playback >,
165	a_row < Paused , open_close , Open , &p::stop_and_open >
166	// +---------+-------------+---------+---------------------+----------------------+
167	> {};
168	// Replaces the default no-transition response.
169	template <class FSM,class Event>
170	void no_transition(Event const& e, FSM&,int state)
171	{
172	std::cout << "no transition from state " << state
173	<< " on event " << typeid(e).name() << std::endl;
174	}
175	};
176	// Pick a back-end
177	typedef msm::back::state_machine<player_> player;
178
179	//
180	// Testing utilities.
181	//
182	static char const* const state_names[] = { "Stopped", "Open", "Empty", "Playing", "Paused" };
183	void pstate(player const& p)
184	{
185	std::cout << " -> " << state_names[p.current_state()[0]] << std::endl;
186	}
187
188	void test()
189	{
190	player p;
191	// needed to start the highest-level SM. This will call on_entry and mark the start of the SM
192	p.start();
193	p.get_state<player_::Empty&>().some_dummy_data=3;
194	p.front_end_data=4;
195
196	// go to Open, call on_exit on Empty, then action, then on_entry on Open
197	p.process_event(open_close()); pstate(p);
198
199	std::ofstream ofs("fsm.txt");
200	// save fsm to archive (current state is Open)
201	{
202	boost::archive::text_oarchive oa(ofs);
203	// write class instance to archive
204	oa << p;
205	}
206	// reload fsm in state Open
207	player p2;
208	{
209	// create and open an archive for input
210	std::ifstream ifs("fsm.txt");
211	boost::archive::text_iarchive ia(ifs);
212	// read class state from archive
213	ia >> p2;
214	}
215	// we now use p2 as it was loaded
216	// check that we kept Empty's data value
217	std::cout << "Empty's data should be 3:" << p2.get_state<player_::Empty&>().some_dummy_data << std::endl;
218	std::cout << "front-end data should be 4:" << p2.front_end_data << std::endl;
219
220	p2.process_event(open_close()); pstate(p2);
221	// will be rejected, wrong disk type
222	p2.process_event(
223	cd_detected("louie, louie",DISK_DVD)); pstate(p2);
224	p2.process_event(
225	cd_detected("louie, louie",DISK_CD)); pstate(p2);
226	p2.process_event(play());
227
228	// at this point, Play is active
229	p2.process_event(pause()); pstate(p2);
230	// go back to Playing
231	p2.process_event(end_pause()); pstate(p2);
232	p2.process_event(pause()); pstate(p2);
233	p2.process_event(stop()); pstate(p2);
234	// event leading to the same state
235	// no action method called as it is not present in the transition table
236	p2.process_event(stop()); pstate(p2);
237	}
238	}
239	// eliminate object tracking (even if serialized through a pointer)
240	// at the risk of a programming error creating duplicate objects.
241	// this is to get rid of warning because p is not const
242	BOOST_CLASS_TRACKING(player, boost::serialization::track_never)
243
244	int main()
245	{
246	test();
247	return 0;
248	}