libs/msm/doc/HTML/examples/SimpleTimer.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>
#include <boost/msm/back/state_machine.hpp>
#include <boost/msm/front/euml/euml.hpp>
using namespace std;
using namespace boost::msm::front::euml;
namespace msm = boost::msm;
// how long the timer will ring when countdown elapsed.
#define RINGING_TIME 5
namespace // Concrete FSM implementation
{
// events
BOOST_MSM_EUML_DECLARE_ATTRIBUTE(int,m_timer)
BOOST_MSM_EUML_ATTRIBUTES((attributes_ << m_timer ), start_timer_attr)
BOOST_MSM_EUML_EVENT_WITH_ATTRIBUTES(start_timer,start_timer_attr)
BOOST_MSM_EUML_EVENT(stop_timer)
BOOST_MSM_EUML_DECLARE_ATTRIBUTE(int,m_tick)
BOOST_MSM_EUML_ATTRIBUTES((attributes_ << m_tick ), tick_attr)
BOOST_MSM_EUML_EVENT_WITH_ATTRIBUTES(tick,tick_attr)
BOOST_MSM_EUML_EVENT(start_ringing)
// Concrete FSM implementation
// The list of FSM states
BOOST_MSM_EUML_ACTION(Stopped_Entry)
{
template <class Event,class FSM,class STATE>
void operator()(Event const&,FSM&,STATE& )
{
std::cout << "entering: Stopped" << std::endl;
}
};
BOOST_MSM_EUML_STATE(( Stopped_Entry ),Stopped)
BOOST_MSM_EUML_ACTION(Started_Entry)
{
template <class Event,class FSM,class STATE>
void operator()(Event const&,FSM&,STATE& )
{
std::cout << "entering: Started" << std::endl;
}
};
BOOST_MSM_EUML_DECLARE_ATTRIBUTE(int,m_counter)
BOOST_MSM_EUML_STATE(( Started_Entry,
no_action,
attributes_ << m_counter
),
Started)
BOOST_MSM_EUML_ACTION(Ringing_Entry)
{
template <class Event,class FSM,class STATE>
void operator()(Event const&,FSM&,STATE& )
{
std::cout << "entering: Ringing" << std::endl;
}
};
BOOST_MSM_EUML_DECLARE_ATTRIBUTE(int,m_ringing_cpt)
BOOST_MSM_EUML_STATE(( Ringing_Entry,
no_action,
attributes_ << m_ringing_cpt
),
Ringing)
// external function
void do_ring(int ringing_time) {std::cout << "ringing " << ringing_time << " s" << std::endl;}
// create functor and eUML function
BOOST_MSM_EUML_FUNCTION(Ring_ , do_ring , ring_ , void , void )
// replaces the old transition table
BOOST_MSM_EUML_TRANSITION_TABLE((
// +------------------------------------------------------------------------------+
// When we start the countdown, the countdown value is not hardcoded but contained in the start_timer event.
// We copy this value into Started
Started == Stopped + start_timer /(target_(m_counter)= event_(m_timer)) ,
Stopped == Started + stop_timer ,
// internal transition
Started + tick
// we here use the message queue to move to Started when the countdown is finished
// to do this we put start_ringing into the message queue
/ if_then_( (source_(m_counter) -= event_(m_tick) ) <= Int_<0>(),
process_(start_ringing) ) ,
// when we start ringing, we give to the state its hard-coded ringing time.
Ringing == Started + start_ringing
/ (target_(m_ringing_cpt) = Int_<RINGING_TIME>(),
// call the external do_ring function
ring_(Int_<RINGING_TIME>())) ,
// to change a bit, we now do not use the message queue but a transition conflict to solve the same problem.
// When tick is fired, we have an internal transition Ringing -> Ringing, as long as Counter > 0
Ringing + tick [ source_(m_ringing_cpt) - event_(m_tick) > Int_<0>() ]
/(target_(m_ringing_cpt) -= event_(m_tick) ) ,
// And we move to Stopped when the counter is 0
Stopped == Ringing + tick[source_(m_ringing_cpt)-event_(m_tick) <= Int_<0>()] ,
// we let the user manually stop the ringing by pressing any button
Stopped == Ringing + stop_timer ,
Stopped == Ringing + start_timer
// +------------------------------------------------------------------------------+
),transition_table)
// create a state machine "on the fly"
BOOST_MSM_EUML_DECLARE_STATE_MACHINE(( transition_table, //STT
init_ << Stopped // Init State
),
SimpleTimer_) //fsm name
// choice of back-end
typedef msm::back::state_machine<SimpleTimer_> SimpleTimer;
//
// Testing utilities.
//
static char const* const state_names[] = { "Stopped", "Started","Ringing" };
void pstate(SimpleTimer const& p)
{
std::cout << " -> " << state_names[p.current_state()[0]] << std::endl;
}
void test()
{
SimpleTimer p;
// needed to start the highest-level SM. This will call on_entry and mark the start of the SM
p.start();
p.process_event(start_timer(5));pstate(p); //timer set to 5 ticks
p.process_event(tick(2));pstate(p);
p.process_event(tick(1));pstate(p);
p.process_event(tick(1));pstate(p);
p.process_event(tick(1));pstate(p);
// we are now ringing, let it ring a bit
p.process_event(tick(2));pstate(p);
p.process_event(tick(1));pstate(p);
p.process_event(tick(1));pstate(p);
p.process_event(tick(1));pstate(p);
}
}
int main()
{
test();
return 0;
}