228 lines
9.5 KiB
C++
228 lines
9.5 KiB
C++
// 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>
|
|
#include <boost/msm/front/row2.hpp>
|
|
|
|
namespace msm = boost::msm;
|
|
namespace mpl = boost::mpl;
|
|
using namespace msm::front;
|
|
|
|
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_>
|
|
{
|
|
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;}
|
|
void open_drawer(open_close const&) { std::cout << "Empty::open_drawer\n"; }
|
|
// actions for Empty's internal transitions
|
|
void internal_action(cd_detected const&){ std::cout << "Empty::internal action\n"; }
|
|
bool internal_guard(cd_detected const&)
|
|
{
|
|
std::cout << "Empty::internal guard\n";
|
|
return false;
|
|
}
|
|
};
|
|
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;}
|
|
void close_drawer(open_close const&) { std::cout << "Open::close_drawer\n"; }
|
|
void stop_and_open(open_close const&) { std::cout << "Open::stop_and_open\n"; }
|
|
};
|
|
|
|
// 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;
|
|
void start_playback(play const&) { std::cout << "Stopped::start_playback\n"; }
|
|
void stop_playback(stop const&) { std::cout << "Stopped::stop_playback\n"; }
|
|
};
|
|
|
|
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;}
|
|
// guard conditions
|
|
// 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;
|
|
}
|
|
};
|
|
|
|
// state not defining any entry or exit
|
|
struct Paused : public msm::front::state<>
|
|
{
|
|
void pause_playback(pause const&) { std::cout << "Paused::pause_playback\n"; }
|
|
void resume_playback(end_pause const&) { std::cout << "Paused::resume_playback\n"; }
|
|
};
|
|
|
|
// action
|
|
void store_cd_info(cd_detected const&) { std::cout << "Player::store_cd_info\n"; }
|
|
|
|
// guard
|
|
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;
|
|
}
|
|
// the initial state of the player SM. Must be defined
|
|
typedef Empty initial_state;
|
|
|
|
// Transition table for player
|
|
struct transition_table : mpl::vector<
|
|
// Start Event Next Action/Guard
|
|
// +---------+-------------+---------+---------------------+----------------------+
|
|
a_row2 < Stopped , play , Playing , Stopped , &Stopped::start_playback >,
|
|
a_row2 < Stopped , open_close , Open , Empty , &Empty::open_drawer >,
|
|
_row < Stopped , stop , Stopped >,
|
|
// +---------+-------------+---------+---------------------+----------------------+
|
|
a_row2 < Open , open_close , Empty , Open , &Open::close_drawer >,
|
|
// +---------+-------------+---------+---------------------+----------------------+
|
|
a_row2 < Empty , open_close , Open , Empty ,&Empty::open_drawer >,
|
|
row2 < Empty , cd_detected , Stopped , player_ ,&player_::store_cd_info
|
|
, player_ ,&player_::good_disk_format >,
|
|
row2 < Empty , cd_detected , Playing , player_ ,&player_::store_cd_info
|
|
, Playing ,&Playing::auto_start >,
|
|
// conflict with some internal rows
|
|
irow2 < Empty , cd_detected , Empty ,&Empty::internal_action
|
|
, Empty ,&Empty::internal_guard >,
|
|
g_irow2 < Empty , cd_detected , Empty ,&Empty::internal_guard >,
|
|
// +---------+-------------+---------+---------------------+----------------------+
|
|
a_row2 < Playing , stop , Stopped , Stopped ,&Stopped::stop_playback >,
|
|
a_row2 < Playing , pause , Paused , Paused ,&Paused::pause_playback >,
|
|
a_row2 < Playing , open_close , Open , Open ,&Open::stop_and_open >,
|
|
// +---------+-------------+---------+---------------------+----------------------+
|
|
a_row2 < Paused , end_pause , Playing , Paused ,&Paused::resume_playback >,
|
|
a_row2 < Paused , stop , Stopped , Stopped ,&Stopped::stop_playback >,
|
|
a_row2 < Paused , open_close , Open , Open ,&Open::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);
|
|
// 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);
|
|
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;
|
|
}
|