188 lines
7.7 KiB
C++
188 lines
7.7 KiB
C++
// Copyright 2010 Christophe Henry
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// henry UNDERSCORE christophe AT hotmail DOT com
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// This is an extended version of the state machine available in the boost::mpl library
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// Distributed under the same license as the original.
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// Copyright for the original version:
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// Copyright 2005 David Abrahams and Aleksey Gurtovoy. Distributed
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// under the Boost Software License, Version 1.0. (See accompanying
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// file LICENSE_1_0.txt or copy at
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// http://www.boost.org/LICENSE_1_0.txt)
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#include <vector>
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#include <iostream>
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#include <boost/msm/back/state_machine.hpp>
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#include <boost/msm/front/euml/euml.hpp>
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using namespace std;
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using namespace boost::msm::front::euml;
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namespace msm = boost::msm;
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// entry/exit/action/guard logging functors
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#include "logging_functors.h"
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namespace // Concrete FSM implementation
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{
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// events
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BOOST_MSM_EUML_EVENT(play)
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BOOST_MSM_EUML_EVENT(end_pause)
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BOOST_MSM_EUML_EVENT(stop)
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BOOST_MSM_EUML_EVENT(pause)
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BOOST_MSM_EUML_EVENT(open_close)
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// A "complicated" event type that carries some data.
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BOOST_MSM_EUML_DECLARE_ATTRIBUTE(std::string,cd_name)
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BOOST_MSM_EUML_DECLARE_ATTRIBUTE(DiskTypeEnum,cd_type)
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BOOST_MSM_EUML_ATTRIBUTES((attributes_ << cd_name << cd_type ), cd_detected_attributes)
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BOOST_MSM_EUML_EVENT_WITH_ATTRIBUTES(cd_detected,cd_detected_attributes)
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// Concrete FSM implementation
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// The list of FSM states
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// state not needing any entry or exit
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BOOST_MSM_EUML_STATE((),Paused)
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// it is also possible to define a state which you can implement normally
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// just make it a state, as usual, and also a grammar terminal, euml_state
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struct Empty_impl : public msm::front::state<> , public euml_state<Empty_impl>
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{
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// this allows us to add some functions
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void activate_empty() {std::cout << "switching to Empty " << std::endl;}
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// standard entry behavior
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template <class Event,class FSM>
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void on_entry(Event const& evt,FSM& fsm)
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{
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std::cout << "entering: Empty" << std::endl;
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}
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template <class Event,class FSM>
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void on_exit(Event const& evt,FSM& fsm)
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{
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std::cout << "leaving: Empty" << std::endl;
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}
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};
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//instance for use in the transition table
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Empty_impl const Empty;
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// create a functor and a eUML function for the activate_empty method from Entry
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BOOST_MSM_EUML_METHOD(ActivateEmpty_ , activate_empty , activate_empty_ , void , void )
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// define more states
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BOOST_MSM_EUML_STATE(( Open_Entry,Open_Exit ),Open)
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BOOST_MSM_EUML_STATE(( Stopped_Entry,Stopped_Exit ),Stopped)
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BOOST_MSM_EUML_STATE(( Playing_Entry,Playing_Exit ),Playing)
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// guard conditions
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BOOST_MSM_EUML_ACTION(good_disk_format)
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{
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template <class FSM,class EVT,class SourceState,class TargetState>
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bool operator()(EVT const& evt,FSM&,SourceState& ,TargetState& )
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{
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// to test a guard condition, let's say we understand only CDs, not DVD
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if (evt.get_attribute(cd_type)!=DISK_CD)
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{
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std::cout << "wrong disk, sorry" << std::endl;
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// just for logging, does not block any transition
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return true;
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}
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std::cout << "good disk" << std::endl;
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return true;
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}
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};
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// it is also possible to use a plain functor, with default-constructor in the transition table
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struct start_play
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{
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template <class FSM,class EVT,class SourceState,class TargetState>
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void operator()(EVT const& ,FSM&,SourceState& ,TargetState& )
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{
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cout << "player::start_play" << endl;
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}
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};
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// replaces the old transition table
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BOOST_MSM_EUML_TRANSITION_TABLE((
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Playing == Stopped + play / start_play() ,
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Playing == Paused + end_pause / resume_playback,
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// +------------------------------------------------------------------------------+
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Empty == Open + open_close / (close_drawer,activate_empty_(target_)),
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// +------------------------------------------------------------------------------+
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Open == Empty + open_close / open_drawer,
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Open == Paused + open_close / stop_and_open,
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Open == Stopped + open_close / open_drawer,
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Open == Playing + open_close / stop_and_open,
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// +------------------------------------------------------------------------------+
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Paused == Playing + pause / pause_playback,
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// +------------------------------------------------------------------------------+
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Stopped == Playing + stop / stop_playback,
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Stopped == Paused + stop / stop_playback,
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Stopped == Empty + cd_detected [good_disk_format &&
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(event_(cd_type)==Int_<DISK_CD>())]
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/ (store_cd_info,process_(play)),
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Stopped == Stopped + stop
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// +------------------------------------------------------------------------------+
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),transition_table)
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// create a state machine "on the fly"
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BOOST_MSM_EUML_DECLARE_STATE_MACHINE(( transition_table, //STT
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init_ << Empty, // Init State
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no_action, // Entry
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no_action, // Exit
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attributes_ << no_attributes_, // Attributes
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configure_ << no_configure_, // configuration
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Log_No_Transition // no_transition handler
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),
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player_) //fsm name
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// or simply, if no no_transition handler needed:
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//BOOST_MSM_EUML_DECLARE_STATE_MACHINE(( transition_table, //STT
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// Empty // Init State
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// ),player_)
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// choice of back-end
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typedef msm::back::state_machine<player_> player;
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//
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// Testing utilities.
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//
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static char const* const state_names[] = { "Stopped", "Paused", "Open", "Empty", "Playing" };
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void pstate(player const& p)
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{
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std::cout << " -> " << state_names[p.current_state()[0]] << std::endl;
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}
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void test()
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{
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player p;
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// needed to start the highest-level SM. This will call on_entry and mark the start of the SM
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p.start();
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// note that we write open_close and not open_close(), like usual. Both are possible with eUML, but
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// you now have less to type.
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// go to Open, call on_exit on Empty, then action, then on_entry on Open
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p.process_event(open_close); pstate(p);
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p.process_event(open_close); pstate(p);
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// will be rejected, wrong disk type
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p.process_event(
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cd_detected("louie, louie",DISK_DVD)); pstate(p);
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p.process_event(
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cd_detected("louie, louie",DISK_CD)); pstate(p);
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// no need to call play as the previous event does it in its action method
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//p.process_event(play);
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// at this point, Play is active
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p.process_event(pause); pstate(p);
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// go back to Playing
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p.process_event(end_pause); pstate(p);
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p.process_event(pause); pstate(p);
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p.process_event(stop); pstate(p);
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// event leading to the same state
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// no action method called as none is defined in the transition table
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p.process_event(stop); pstate(p);
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// test call to no_transition
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p.process_event(pause); pstate(p);
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}
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}
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int main()
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{
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test();
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return 0;
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}
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