[ceph.git] / ceph / src / boost / libs / msm / doc / PDF / examples / SimpleWithFunctors.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 <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>

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_>
    {
        template <class Event,class FSM>
        void on_entry(Event const& ,FSM&) 
        {
            std::cout << "entering: Player" << std::endl;
        }
        template <class Event,class FSM>
        void on_exit(Event const&,FSM& ) 
        {
            std::cout << "leaving: Player" << std::endl;
        }

        // 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<>
        {
            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
        // 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);
        std::cout << "stop fsm" << std::endl;
        p.stop();

    }
}

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 <vector>
	12	#include <iostream>
	13	// back-end
	14	#include <boost/msm/back/state_machine.hpp>
	15	//front-end
	16	#include <boost/msm/front/state_machine_def.hpp>
	17	// functors
	18	#include <boost/msm/front/functor_row.hpp>
	19	#include <boost/msm/front/euml/common.hpp>
	20	// for And_ operator
	21	#include <boost/msm/front/euml/operator.hpp>
	22
	23	using namespace std;
	24	namespace msm = boost::msm;
	25	namespace mpl = boost::mpl;
	26	using namespace msm::front;
	27	// for And_ operator
	28	using namespace msm::front::euml;
	29
	30	namespace // Concrete FSM implementation
	31	{
	32	// events
	33	struct play {};
	34	struct end_pause {};
	35	struct stop {};
	36	struct pause {};
	37	struct open_close {};
	38
	39	// A "complicated" event type that carries some data.
	40	enum DiskTypeEnum
	41	{
	42	DISK_CD=0,
	43	DISK_DVD=1
	44	};
	45	struct cd_detected
	46	{
	47	cd_detected(std::string name, DiskTypeEnum diskType)
	48	: name(name),
	49	disc_type(diskType)
	50	{}
	51
	52	std::string name;
	53	DiskTypeEnum disc_type;
	54	};
	55
	56	// front-end: define the FSM structure
	57	struct player_ : public msm::front::state_machine_def<player_>
	58	{
	59	template <class Event,class FSM>
	60	void on_entry(Event const& ,FSM&)
	61	{
	62	std::cout << "entering: Player" << std::endl;
	63	}
	64	template <class Event,class FSM>
65	void on_exit(Event const&,FSM& )
66	{
67	std::cout << "leaving: Player" << std::endl;
68	}
69
70	// The list of FSM states
71	struct Empty : public msm::front::state<>
72	{
73	// every (optional) entry/exit methods get the event passed.
74	template <class Event,class FSM>
75	void on_entry(Event const&,FSM& ) {std::cout << "entering: Empty" << std::endl;}
76	template <class Event,class FSM>
77	void on_exit(Event const&,FSM& ) {std::cout << "leaving: Empty" << std::endl;}
78	};
79	struct Open : public msm::front::state<>
80	{
81	template <class Event,class FSM>
82	void on_entry(Event const& ,FSM&) {std::cout << "entering: Open" << std::endl;}
83	template <class Event,class FSM>
84	void on_exit(Event const&,FSM& ) {std::cout << "leaving: Open" << std::endl;}
85	};
86
87	struct Stopped : public msm::front::state<>
88	{
89	// when stopped, the CD is loaded
90	template <class Event,class FSM>
91	void on_entry(Event const& ,FSM&) {std::cout << "entering: Stopped" << std::endl;}
92	template <class Event,class FSM>
93	void on_exit(Event const&,FSM& ) {std::cout << "leaving: Stopped" << std::endl;}
94	};
95
96	struct Playing : public msm::front::state<>
97	{
98	template <class Event,class FSM>
99	void on_entry(Event const&,FSM& ) {std::cout << "entering: Playing" << std::endl;}
100	template <class Event,class FSM>
101	void on_exit(Event const&,FSM& ) {std::cout << "leaving: Playing" << std::endl;}
102	};
103
104	// state not defining any entry or exit
105	struct Paused : public msm::front::state<>
106	{
107	};
108
109	// the initial state of the player SM. Must be defined
110	typedef Empty initial_state;
111
112	// transition actions
113	// as the functors are generic on events, fsm and source/target state,
114	// you can reuse them in another machine if you wish
115	struct TestFct
116	{
117	template <class EVT,class FSM,class SourceState,class TargetState>
118	void operator()(EVT const&, FSM&,SourceState& ,TargetState& )
119	{
120	cout << "transition with event:" << typeid(EVT).name() << endl;
121	}
122	};
123	struct start_playback
124	{
125	template <class EVT,class FSM,class SourceState,class TargetState>
126	void operator()(EVT const& ,FSM& ,SourceState& ,TargetState& )
127	{
128	cout << "player::start_playback" << endl;
129	}
130	};
131	struct open_drawer
132	{
133	template <class EVT,class FSM,class SourceState,class TargetState>
134	void operator()(EVT const& ,FSM& ,SourceState& ,TargetState& )
135	{
136	cout << "player::open_drawer" << endl;
137	}
138	};
139	struct close_drawer
140	{
141	template <class EVT,class FSM,class SourceState,class TargetState>
142	void operator()(EVT const& ,FSM& ,SourceState& ,TargetState& )
143	{
144	cout << "player::close_drawer" << endl;
145	}
146	};
147	struct store_cd_info
148	{
149	template <class EVT,class FSM,class SourceState,class TargetState>
150	void operator()(EVT const&,FSM& fsm ,SourceState& ,TargetState& )
151	{
152	cout << "player::store_cd_info" << endl;
153	fsm.process_event(play());
154	}
155	};
156	struct stop_playback
157	{
158	template <class EVT,class FSM,class SourceState,class TargetState>
159	void operator()(EVT const& ,FSM& ,SourceState& ,TargetState& )
160	{
161	cout << "player::stop_playback" << endl;
162	}
163	};
164	struct pause_playback
165	{
166	template <class EVT,class FSM,class SourceState,class TargetState>
167	void operator()(EVT const& ,FSM& ,SourceState& ,TargetState& )
168	{
169	cout << "player::pause_playback" << endl;
170	}
171	};
172	struct resume_playback
173	{
174	template <class EVT,class FSM,class SourceState,class TargetState>
175	void operator()(EVT const& ,FSM& ,SourceState& ,TargetState& )
176	{
177	cout << "player::resume_playback" << endl;
178	}
179	};
180	struct stop_and_open
181	{
182	template <class EVT,class FSM,class SourceState,class TargetState>
183	void operator()(EVT const& ,FSM& ,SourceState& ,TargetState& )
184	{
185	cout << "player::stop_and_open" << endl;
186	}
187	};
188	struct stopped_again
189	{
190	template <class EVT,class FSM,class SourceState,class TargetState>
191	void operator()(EVT const& ,FSM& ,SourceState& ,TargetState& )
192	{
193	cout << "player::stopped_again" << endl;
194	}
195	};
196	// guard conditions
197	struct DummyGuard
198	{
199	template <class EVT,class FSM,class SourceState,class TargetState>
200	bool operator()(EVT const& evt,FSM& fsm,SourceState& src,TargetState& tgt)
201	{
202	return true;
203	}
204	};
205	struct good_disk_format
206	{
207	template <class EVT,class FSM,class SourceState,class TargetState>
208	bool operator()(EVT const& evt ,FSM&,SourceState& ,TargetState& )
209	{
210	// to test a guard condition, let's say we understand only CDs, not DVD
211	if (evt.disc_type != DISK_CD)
212	{
213	std::cout << "wrong disk, sorry" << std::endl;
214	return false;
215	}
216	return true;
217	}
218	};
219	struct always_true
220	{
221	template <class EVT,class FSM,class SourceState,class TargetState>
222	bool operator()(EVT const& evt ,FSM&,SourceState& ,TargetState& )
223	{
224	return true;
225	}
226	};
227	// we want to define one row with the classic look.
228	bool auto_start(cd_detected const& evt)
229	{
230	return false;
231	}
232
233	typedef player_ p; // makes transition table cleaner
234
235	// Transition table for player
236	struct transition_table : mpl::vector<
237	// Start Event Next Action Guard
238	// +---------+-------------+---------+---------------------------+----------------------+
239	Row < Stopped , play , Playing , ActionSequence_
240	<mpl::vector<
241	TestFct,start_playback> >
242	, DummyGuard >,
243	Row < Stopped , open_close , Open , open_drawer , none >,
244	Row < Stopped , stop , Stopped , none , none >,
245	// +---------+-------------+---------+---------------------------+----------------------+
246	Row < Open , open_close , Empty , close_drawer , none >,
247	// +---------+-------------+---------+---------------------------+----------------------+
248	Row < Empty , open_close , Open , open_drawer , none >,
249	Row < Empty , cd_detected , Stopped , store_cd_info , And_<good_disk_format,
250	always_true> >,
251	// we here also mix with some "classical row"
252	g_row < Empty , cd_detected , Playing , &p::auto_start >,
253	// +---------+-------------+---------+---------------------------+----------------------+
254	Row < Playing , stop , Stopped , stop_playback , none >,
255	Row < Playing , pause , Paused , pause_playback , none >,
256	Row < Playing , open_close , Open , stop_and_open , none >,
257	// +---------+-------------+---------+---------------------------+----------------------+
258	Row < Paused , end_pause , Playing , resume_playback , none >,
259	Row < Paused , stop , Stopped , stop_playback , none >,
260	Row < Paused , open_close , Open , stop_and_open , none >
261	// +---------+-------------+---------+---------------------------+----------------------+
262	> {};
263	// Replaces the default no-transition response.
264	template <class FSM,class Event>
265	void no_transition(Event const& e, FSM&,int state)
266	{
267	std::cout << "no transition from state " << state
268	<< " on event " << typeid(e).name() << std::endl;
269	}
270	};
271	// Pick a back-end
272	typedef msm::back::state_machine<player_> player;
273
274	//
275	// Testing utilities.
276	//
277	static char const* const state_names[] = { "Stopped", "Open", "Empty", "Playing", "Paused" };
278	void pstate(player const& p)
279	{
280	std::cout << " -> " << state_names[p.current_state()[0]] << std::endl;
281	}
282
283	void test()
284	{
285	player p;
286	// needed to start the highest-level SM. This will call on_entry and mark the start of the SM
287	p.start();
288	// go to Open, call on_exit on Empty, then action, then on_entry on Open
289	p.process_event(open_close()); pstate(p);
290	p.process_event(open_close()); pstate(p);
291	// will be rejected, wrong disk type
292	p.process_event(
293	cd_detected("louie, louie",DISK_DVD)); pstate(p);
294	p.process_event(
295	cd_detected("louie, louie",DISK_CD)); pstate(p);
296	// no need to call play() as the previous event does it in its action method
297	//p.process_event(play());
298
299	// at this point, Play is active
300	p.process_event(pause()); pstate(p);
301	// go back to Playing
302	p.process_event(end_pause()); pstate(p);
303	p.process_event(pause()); pstate(p);
304	p.process_event(stop()); pstate(p);
305	// event leading to the same state
306	// no action method called as it is not present in the transition table
307	p.process_event(stop()); pstate(p);
308	std::cout << "stop fsm" << std::endl;
309	p.stop();
310
311	}
312	}
313
314	int main()
315	{
316	test();
317	return 0;
318	}