| // 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> |
| // functors |
| #include <boost/msm/front/functor_row.hpp> |
| #include <boost/msm/front/euml/common.hpp> |
| |
| |
| using namespace std; |
| namespace msm = boost::msm; |
| namespace mpl = boost::mpl; |
| using namespace msm::front; |
| |
| namespace // Concrete FSM implementation |
| { |
| // events |
| struct disconnect {}; |
| struct connect {}; |
| |
| // flag |
| struct is_connected{}; |
| // front-end: define the FSM structure |
| struct Connection_ : public msm::front::state_machine_def<Connection_> |
| { |
| // when a transition is about to be taken, we already update our currently active state(s) |
| typedef msm::active_state_switch_before_transition active_state_switch_policy; |
| |
| // The list of FSM states |
| struct Connected : public msm::front::state<> |
| { |
| // in this state, we are connected |
| typedef mpl::vector1<is_connected> flag_list; |
| template <class Event,class FSM> |
| void on_entry(Event const&,FSM& ) {std::cout << "entering: Connected" << std::endl;} |
| template <class Event,class FSM> |
| void on_exit(Event const&,FSM& ) {std::cout << "leaving: Connected" << std::endl;} |
| }; |
| struct Disconnected : public msm::front::state<> |
| { |
| template <class Event,class FSM> |
| void on_entry(Event const& ,FSM&) {std::cout << "entering: Disconnected" << std::endl;} |
| template <class Event,class FSM> |
| void on_exit(Event const&,FSM& ) {std::cout << "leaving: Disconnected" << std::endl;} |
| }; |
| |
| // transition actions |
| struct SignalConnect |
| { |
| template <class EVT,class FSM,class SourceState,class TargetState> |
| void operator()(EVT const&, FSM& fsm,SourceState& ,TargetState& ) |
| { |
| // by default, this would be wrong (shows false) |
| cout << "SignalConnect. Connected? " << std::boolalpha << fsm.template is_flag_active<is_connected>() << endl; |
| } |
| }; |
| struct SignalDisconnect |
| { |
| template <class EVT,class FSM,class SourceState,class TargetState> |
| void operator()(EVT const&, FSM& fsm,SourceState& ,TargetState& ) |
| { |
| // by default, this would be wrong (shows true) |
| cout << "SignalDisconnect. Connected? " << std::boolalpha << fsm.template is_flag_active<is_connected>() << endl; |
| } |
| }; |
| |
| // the initial state of the player SM. Must be defined |
| typedef Disconnected initial_state; |
| |
| // Transition table for player |
| struct transition_table : mpl::vector< |
| // Start Event Next Action Guard |
| // +--------------+-------------+--------------+---------------------------+----------------------+ |
| Row < Connected , disconnect , Disconnected , SignalDisconnect , none >, |
| Row < Disconnected , connect , Connected , SignalConnect , none > |
| // +--------------+-------------+--------------+---------------------------+----------------------+ |
| > {}; |
| // 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<Connection_> Connection; |
| |
| |
| void test() |
| { |
| Connection connection; |
| // needed to start the highest-level SM. This will call on_entry and mark the start of the SM |
| connection.start(); |
| // signal a connection |
| connection.process_event(connect()); |
| // signal a disconnection |
| connection.process_event(disconnect()); |
| connection.stop(); |
| } |
| } |
| |
| int main() |
| { |
| test(); |
| return 0; |
| } |