321 lines
12 KiB
C++
321 lines
12 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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// back-end
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#include <boost/msm/back/state_machine.hpp>
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//front-end
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#include <boost/msm/front/state_machine_def.hpp>
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// functors
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#include <boost/msm/front/functor_row.hpp>
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#include <boost/msm/front/euml/common.hpp>
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// for And_ operator
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#include <boost/msm/front/euml/operator.hpp>
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// for func_state and func_state_machine
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#include <boost/msm/front/euml/state_grammar.hpp>
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using namespace std;
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namespace msm = boost::msm;
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namespace mpl = boost::mpl;
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using namespace msm::front;
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// for And_ operator
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using namespace msm::front::euml;
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namespace // Concrete FSM implementation
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{
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// events
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struct play {};
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struct end_pause {};
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struct stop {};
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struct pause {};
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struct open_close {};
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// A "complicated" event type that carries some data.
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enum DiskTypeEnum
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{
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DISK_CD=0,
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DISK_DVD=1
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};
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struct cd_detected
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{
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cd_detected(std::string name, DiskTypeEnum diskType)
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: name(name),
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disc_type(diskType)
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{}
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std::string name;
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DiskTypeEnum disc_type;
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};
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// front-end: define the FSM structure
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struct player_ : public msm::front::state_machine_def<player_>
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{
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// The list of FSM states
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// entry and exit functors for Empty
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struct Empty_Entry
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{
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template <class Event,class FSM,class STATE>
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void operator()(Event const&,FSM&,STATE& )
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{
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std::cout << "entering: Empty" << std::endl;
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}
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};
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struct Empty_Exit
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{
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template <class Event,class FSM,class STATE>
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void operator()(Event const&,FSM&,STATE& )
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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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// definition of Empty
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struct Empty_tag {};
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typedef msm::front::euml::func_state<Empty_tag,Empty_Entry,Empty_Exit> Empty;
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struct Open_Entry
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{
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template <class Event,class FSM,class STATE>
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void operator()(Event const&,FSM&,STATE& )
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{
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std::cout << "entering: Open" << std::endl;
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}
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};
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struct Open_Exit
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{
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template <class Event,class FSM,class STATE>
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void operator()(Event const&,FSM&,STATE& )
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{
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std::cout << "leaving: Open" << std::endl;
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}
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};
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struct Open_tag {};
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typedef msm::front::euml::func_state<Open_tag,Open_Entry,Open_Exit> Open;
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// states without entry/exit actions (can be declared as functor state, just without functors ;-) )
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struct Stopped_tag {};
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typedef msm::front::euml::func_state<Stopped_tag> Stopped;
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struct Playing_tag {};
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typedef msm::front::euml::func_state<Playing_tag> Playing;
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// state not defining any entry or exit (declared as simple state. Equivalent)
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struct Paused : public msm::front::state<>
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{
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};
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// the initial state of the player SM. Must be defined
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typedef Empty initial_state;
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// transition actions
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// as the functors are generic on events, fsm and source/target state,
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// you can reuse them in another machine if you wish
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struct TestFct
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{
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template <class EVT,class FSM,class SourceState,class TargetState>
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void operator()(EVT const&, FSM&,SourceState& ,TargetState& )
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{
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cout << "transition with event:" << typeid(EVT).name() << endl;
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}
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};
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struct start_playback
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{
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template <class EVT,class FSM,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_playback" << endl;
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}
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};
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struct open_drawer
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{
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template <class EVT,class FSM,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::open_drawer" << endl;
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}
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};
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struct close_drawer
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{
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template <class EVT,class FSM,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::close_drawer" << endl;
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}
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};
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struct store_cd_info
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{
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template <class EVT,class FSM,class SourceState,class TargetState>
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void operator()(EVT const&,FSM& fsm ,SourceState& ,TargetState& )
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{
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cout << "player::store_cd_info" << endl;
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fsm.process_event(play());
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}
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};
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struct stop_playback
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{
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template <class EVT,class FSM,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::stop_playback" << endl;
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}
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};
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struct pause_playback
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{
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template <class EVT,class FSM,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::pause_playback" << endl;
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}
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};
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struct resume_playback
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{
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template <class EVT,class FSM,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::resume_playback" << endl;
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}
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};
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struct stop_and_open
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{
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template <class EVT,class FSM,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::stop_and_open" << endl;
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}
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};
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struct stopped_again
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{
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template <class EVT,class FSM,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::stopped_again" << endl;
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}
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};
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// guard conditions
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struct DummyGuard
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{
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template <class EVT,class FSM,class SourceState,class TargetState>
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bool operator()(EVT const& evt,FSM& fsm,SourceState& src,TargetState& tgt)
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{
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return true;
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}
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};
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struct good_disk_format
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{
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template <class EVT,class FSM,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.disc_type != DISK_CD)
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{
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std::cout << "wrong disk, sorry" << std::endl;
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return false;
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}
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return true;
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}
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};
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struct always_true
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{
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template <class EVT,class FSM,class SourceState,class TargetState>
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bool operator()(EVT const& evt ,FSM&,SourceState& ,TargetState& )
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{
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return true;
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}
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};
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// we want to define one row with the classic look.
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bool auto_start(cd_detected const& evt)
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{
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return false;
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}
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typedef player_ p; // makes transition table cleaner
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// Transition table for player
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struct transition_table : mpl::vector<
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// Start Event Next Action Guard
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// +---------+-------------+---------+---------------------------+----------------------+
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Row < Stopped , play , Playing , ActionSequence_
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<mpl::vector<
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TestFct,start_playback> >
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, DummyGuard >,
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Row < Stopped , open_close , Open , open_drawer , none >,
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Row < Stopped , stop , Stopped , none , none >,
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// +---------+-------------+---------+---------------------------+----------------------+
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Row < Open , open_close , Empty , close_drawer , none >,
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// +---------+-------------+---------+---------------------------+----------------------+
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Row < Empty , open_close , Open , open_drawer , none >,
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Row < Empty , cd_detected , Stopped , store_cd_info , And_<good_disk_format,
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always_true> >,
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// we here also mix with some "classical row"
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g_row < Empty , cd_detected , Playing , &p::auto_start >,
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// +---------+-------------+---------+---------------------------+----------------------+
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Row < Playing , stop , Stopped , stop_playback , none >,
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Row < Playing , pause , Paused , pause_playback , none >,
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Row < Playing , open_close , Open , stop_and_open , none >,
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// +---------+-------------+---------+---------------------------+----------------------+
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Row < Paused , end_pause , Playing , resume_playback , none >,
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Row < Paused , stop , Stopped , stop_playback , none >,
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Row < Paused , open_close , Open , stop_and_open , none >
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// +---------+-------------+---------+---------------------------+----------------------+
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> {};
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// Replaces the default no-transition response.
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template <class FSM,class Event>
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void no_transition(Event const& e, FSM&,int state)
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{
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std::cout << "no transition from state " << state
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<< " on event " << typeid(e).name() << std::endl;
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}
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};
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// Pick a 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", "Open", "Empty", "Playing", "Paused" };
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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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// 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 it is not present in the transition table
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p.process_event(stop()); 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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