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// 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>
#include <boost/msm/back/state_machine.hpp>
#include <boost/msm/front/euml/euml.hpp>
using namespace std;
using namespace boost::msm::front::euml;
using namespace boost::msm::front;
namespace msm = boost::msm;
// entry/exit/action/guard logging functors
#include "logging_functors.h"
namespace // Concrete FSM implementation
{
// events
// note that unlike the SimpleTutorial, events must derive from euml_event.
BOOST_MSM_EUML_EVENT(play)
BOOST_MSM_EUML_EVENT(end_pause)
BOOST_MSM_EUML_EVENT(stop)
BOOST_MSM_EUML_EVENT(pause)
BOOST_MSM_EUML_EVENT(open_close)
BOOST_MSM_EUML_EVENT(internal_event)
BOOST_MSM_EUML_EVENT(next_song)
BOOST_MSM_EUML_EVENT(previous_song)
// A "complicated" event type that carries some data.
BOOST_MSM_EUML_DECLARE_ATTRIBUTE(std::string,cd_name)
BOOST_MSM_EUML_DECLARE_ATTRIBUTE(DiskTypeEnum,cd_type)
BOOST_MSM_EUML_ATTRIBUTES((attributes_ << cd_name << cd_type ), cd_detected_attributes)
BOOST_MSM_EUML_EVENT_WITH_ATTRIBUTES(cd_detected,cd_detected_attributes)
// Concrete FSM implementation
// The list of FSM states
BOOST_MSM_EUML_STATE(( Empty_Entry,Empty_Exit ),Empty)
// we just declare a state type but do not create any instance as we want to inherit from this type
BOOST_MSM_EUML_DECLARE_STATE((Open_Entry,Open_Exit),Open_def)
// derive to be able to add an internal transition table
struct Open_impl : public Open_def
{
BOOST_MSM_EUML_DECLARE_INTERNAL_TRANSITION_TABLE((
open_close [internal_guard1] / internal_action1 ,
open_close [internal_guard2] / internal_action2 ,
internal_event / internal_action
))
};
// declare an instance for the stt as we are manually declaring a state
Open_impl const Open;
BOOST_MSM_EUML_STATE(( Stopped_Entry,Stopped_Exit ),Stopped)
// Playing is a state machine itself.
// It has 3 substates
BOOST_MSM_EUML_STATE(( Song1_Entry,Song1_Exit ),Song1)
BOOST_MSM_EUML_STATE(( Song2_Entry,Song2_Exit ),Song2)
BOOST_MSM_EUML_STATE(( Song3_Entry,Song3_Exit ),Song3)
// Playing has a transition table
BOOST_MSM_EUML_TRANSITION_TABLE((
// +------------------------------------------------------------------------------+
Song2 == Song1 + next_song / start_next_song,
Song1 == Song2 + previous_song / start_prev_song,
Song3 == Song2 + next_song / start_next_song,
Song2 == Song3 + previous_song / start_prev_song
// +------------------------------------------------------------------------------+
),playing_transition_table )
BOOST_MSM_EUML_DECLARE_STATE_MACHINE( (playing_transition_table, //STT
init_ << Song1 // Init State
),Playing_def)
// some action for the internal transition
BOOST_MSM_EUML_ACTION(playing_internal_action)
{
template <class FSM,class EVT,class SourceState,class TargetState>
void operator()(EVT const&, FSM& ,SourceState& ,TargetState& )
{
cout << "Playing::internal action" << endl;
}
};
// derive to be able to add an internal transition table
struct Playing_ : public Playing_def
{
BOOST_MSM_EUML_DECLARE_INTERNAL_TRANSITION_TABLE((
internal_event / playing_internal_action
))
};
// choice of back-end
typedef msm::back::state_machine<Playing_> Playing_type;
Playing_type const Playing;
// state not needing any entry or exit
BOOST_MSM_EUML_STATE((),Paused)
// guard conditions
BOOST_MSM_EUML_ACTION(good_disk_format)
{
template <class FSM,class EVT,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.get_attribute(cd_type)!=DISK_CD)
{
std::cout << "wrong disk, sorry" << std::endl;
// just for logging, does not block any transition
return true;
}
std::cout << "good disk" << std::endl;
return true;
}
};
// replaces the old transition table
BOOST_MSM_EUML_TRANSITION_TABLE((
Stopped + play / start_playback == Playing ,
Stopped + open_close / open_drawer == Open ,
Stopped + stop == Stopped ,
// +------------------------------------------------------------------------------+
Open + open_close / close_drawer == Empty ,
// +------------------------------------------------------------------------------+
Empty + open_close / open_drawer == Open ,
Empty + cd_detected
[good_disk_format&&(event_(cd_type)==Int_<DISK_CD>())]
/ (store_cd_info,process_(play))
== Stopped ,
// +------------------------------------------------------------------------------+
Playing + stop / stop_playback == Stopped ,
Playing + pause / pause_playback == Paused ,
Playing + open_close / stop_and_open == Open ,
// +------------------------------------------------------------------------------+
Paused + end_pause / resume_playback == Playing ,
Paused + stop / stop_playback == Stopped ,
Paused + open_close / stop_and_open == Open
// +------------------------------------------------------------------------------+
),transition_table)
// create a state machine "on the fly"
BOOST_MSM_EUML_DECLARE_STATE_MACHINE(( transition_table, //STT
init_ << Empty, // Init State
no_action, // Entry
no_action, // Exit
attributes_ << no_attributes_, // Attributes
configure_ << no_configure_, // configuration
Log_No_Transition // no_transition handler
),
player_) //fsm name
// choice of 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);
std::cout << "sending internal event (not rejected)" << std::endl;
p.process_event(internal_event);
std::cout << "sending open_close event. Conflict with internal transitions (rejecting event)" << std::endl;
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
// make transition happen inside it. Player has no idea about this event but it's ok.
p.process_event(next_song);pstate(p); //2nd song active
p.process_event(next_song);pstate(p);//3rd song active
p.process_event(previous_song);pstate(p);//2nd song active
// event handled internally in Playing, without region checking
std::cout << "sending internal event (not rejected)" << std::endl;
p.process_event(internal_event);
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 none is defined in the transition table
p.process_event(stop); pstate(p);
// test call to no_transition
p.process_event(pause); pstate(p);
}
}
int main()
{
test();
return 0;
}
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