Menu
▾
▴
compare
Compare
On this page, we have implemented the same state machine (the "simple" sample from boost::msm) with various statemachine libraries.
boost::msm
:::cpp
// events
struct play {};
struct end_pause {};
struct stop {};
struct pause {};
struct open_close {};
struct cd_detected{};
// Concrete FSM implementation
struct player_ : public msm::front::state_machine_def<player_>
{
// no need for exception handling or message queue
typedef int no_exception_thrown;
typedef int no_message_queue;
// The list of FSM states
struct Empty : public msm::front::state<>
{
// optional entry/exit methods
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<>
{
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;*/}
};
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&) { }
void open_drawer(open_close const&) { }
void close_drawer(open_close const&) { }
void store_cd_info(cd_detected const& cd) { }
void stop_playback(stop const&) { }
void pause_playback(pause const&) { }
void resume_playback(end_pause const&) { }
void stop_and_open(open_close const&) { }
void stopped_again(stop const&){}
// guard conditions
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 >,
_row < Stopped , open_close , Open >,
_row < Stopped , stop , Stopped >,
// +---------+-------------+---------+---------------------+----------------------+
_row < Open , open_close , Empty >,
// +---------+-------------+---------+---------------------+----------------------+
_row < Empty , open_close , Open >,
_row < Empty , cd_detected , Stopped >,
// +---------+-------------+---------+---------------------+----------------------+
_row < Playing , stop , Stopped >,
_row < Playing , pause , Paused >,
_row < Playing , open_close , Open >,
// +---------+-------------+---------+---------------------+----------------------+
_row < Paused , end_pause , Playing >,
_row < Paused , stop , Stopped >,
_row < Paused , open_close , 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;
}
};
typedef msm::back::state_machine<player_> player;
boost::statechart
:::cpp
//events
struct play : sc::event< play > {};
struct end_pause : sc::event< end_pause > {};
struct stop : sc::event< stop > {};
struct pause : sc::event< pause > {};
struct open_close : sc::event< open_close > {};
struct cd_detected : sc::event< cd_detected > {};
struct Empty;
struct Open;
struct Stopped;
struct Playing;
struct Paused;
// SM
struct player : sc::state_machine< player, Empty >
{
void open_drawer(open_close const&) { /*std::cout << "player::open_drawer\n";*/ }
void store_cd_info(cd_detected const& cd) {/*std::cout << "player::store_cd_info\n";*/ }
void close_drawer(open_close const&) { /*std::cout << "player::close_drawer\n";*/ }
void start_playback(play const&) { /*std::cout << "player::start_playback\n";*/ }
void stopped_again(stop const&) {/*std::cout << "player::stopped_again\n";*/}
void stop_playback(stop const&) { /*std::cout << "player::stop_playback\n";*/ }
void pause_playback(pause const&) { /*std::cout << "player::pause_playback\n"; */}
void stop_and_open(open_close const&) { /*std::cout << "player::stop_and_open\n";*/ }
void resume_playback(end_pause const&) { /*std::cout << "player::resume_playback\n";*/ }
};
struct Empty : sc::simple_state< Empty, player >
{
Empty() { /*std::cout << "entering Empty" << std::endl;*/ } // entry
~Empty() { /*std::cout << "leaving Empty" << std::endl;*/ } // exit
typedef mpl::list<
sc::transition< open_close, Open,
player, &player::open_drawer >,
sc::transition< cd_detected, Stopped,
player, &player::store_cd_info > > reactions;
};
struct Open : sc::simple_state< Open, player >
{
Open() { /*std::cout << "entering Open" << std::endl;*/ } // entry
~Open() { /*std::cout << "leaving Open" << std::endl;*/ } // exit
typedef sc::transition< open_close, Empty,
player, &player::close_drawer > reactions;
};
struct Stopped : sc::simple_state< Stopped, player >
{
Stopped() { /*std::cout << "entering Stopped" << std::endl;*/ } // entry
~Stopped() { /*std::cout << "leaving Stopped" << std::endl;*/ } // exit
typedef mpl::list<
sc::transition< play, Playing,
player, &player::start_playback >,
sc::transition< open_close, Open,
player, &player::open_drawer >,
sc::transition< stop, Stopped,
player, &player::stopped_again > > reactions;
};
struct Playing : sc::simple_state< Playing, player >
{
Playing() { /*std::cout << "entering Playing" << std::endl;*/ } // entry
~Playing() { /*std::cout << "leaving Playing" << std::endl;*/ } // exit
typedef mpl::list<
sc::transition< stop, Stopped,
player, &player::stop_playback >,
sc::transition< pause, Paused,
player, &player::pause_playback >,
sc::transition< open_close, Open,
player, &player::stop_and_open > > reactions;
};
struct Paused : sc::simple_state< Paused, player >
{
Paused() { /*std::cout << "entering Paused" << std::endl;*/ } // entry
~Paused() { /*std::cout << "leaving Paused" << std::endl;*/ } // exit
typedef mpl::list<
sc::transition< end_pause, Playing,
player, &player::resume_playback >,
sc::transition< stop, Stopped,
player, &player::stop_playback >,
sc::transition< open_close, Open,
player, &player::stop_and_open > > reactions;
};
instantFSM
:::cpp
StateMachine sm(
State("Empty", initialTag,
OnEntry([](){/*std::cout << "entering: Empty" << std::endl;*/}),
OnExit([](){/*std::cout << "leaving: Empty" << std::endl;*/}),
Transition( OnEvent("open_close"), Target("Open")),
Transition( OnEvent("cd_detected"),Target("Stopped"))
),
State("Open",
OnEntry([](){/*std::cout << "entering: Open" << std::endl;*/}),
OnExit([](){/*std::cout << "leaving: Open" << std::endl;*/}),
Transition( OnEvent("open_close"), Target("Empty"))
),
State("Stopped",
OnEntry([](){/*std::cout << "entering: Stopped" << std::endl;*/}),
OnExit([](){/*std::cout << "leaving: Stopped" << std::endl;*/}),
Transition( OnEvent("play"), Target("Playing")),
Transition( OnEvent("open_close"), Target("Open")),
Transition( OnEvent("stop"), Target("Stopped"))
),
State("Playing",
OnEntry([](){/*std::cout << "entering: Playing" << std::endl;*/}),
OnExit([](){/*std::cout << "leaving: Playing" << std::endl;*/}),
Transition( OnEvent("stop"), Target("Stopped")),
Transition( OnEvent("pause"), Target("Paused")),
Transition( OnEvent("open_close"), Target("Open"))
),
State("Paused",
OnEntry([](){/*std::cout << "entering: Paused" << std::endl;*/}),
OnExit([](){/*std::cout << "leaving: Paused" << std::endl;*/}),
Transition( OnEvent("stop"), Target("Stopped")),
Transition( OnEvent("end_pause"), Target("Playing")),
Transition( OnEvent("open_close"), Target("Open"))
)
);