libs/msm/doc/HTML/examples/DirectEntryTutorial.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> // back-end #include <boost/msm/back11/state_machine.hpp> //front-end #include <boost/msm/front/state_machine_def.hpp> namespace msm = boost::msm; namespace mpl = boost::mpl; namespace { // events struct event1 {}; struct event2 {}; struct event3 {}; struct event4 {}; struct event5 {}; struct event6 { event6(){} template <class Event> event6(Event const&){} }; // front-end: define the FSM structure struct Fsm_ : public msm::front::state_machine_def<Fsm_> { // The list of FSM states struct State1 : public msm::front::state<> { // every (optional) entry/exit methods get the event passed. template <class Event,class FSM> void on_entry(Event const&,FSM& ) {std::cout << "entering: State1" << std::endl;} template <class Event,class FSM> void on_exit(Event const&,FSM& ) {std::cout << "leaving: State1" << std::endl;} }; struct State2 : public msm::front::state<> { // every (optional) entry/exit methods get the event passed. template <class Event,class FSM> void on_entry(Event const&,FSM& ) {std::cout << "entering: State2" << std::endl;} template <class Event,class FSM> void on_exit(Event const&,FSM& ) {std::cout << "leaving: State2" << std::endl;} }; struct SubFsm2_ : public msm::front::state_machine_def<SubFsm2_> { typedef msm::back11::state_machine<SubFsm2_> SubFsm2; template <class Event,class FSM> void on_entry(Event const&,FSM& ) {std::cout << "entering: SubFsm2" << std::endl;} template <class Event,class FSM> void on_exit(Event const&,FSM& ) {std::cout << "leaving: SubFsm2" << std::endl;} struct SubState1 : public msm::front::state<> { template <class Event,class FSM> void on_entry(Event const&,FSM& ) {std::cout << "entering: SubFsm2::SubState1" << std::endl;} template <class Event,class FSM> void on_exit(Event const&,FSM& ) {std::cout << "leaving: SubFsm2::SubState1" << std::endl;} }; struct SubState1b : public msm::front::state<> { template <class Event,class FSM> void on_entry(Event const&,FSM& ) {std::cout << "entering: SubFsm2::SubState1b" << std::endl;} template <class Event,class FSM> void on_exit(Event const&,FSM& ) {std::cout << "leaving: SubFsm2::SubState1b" << std::endl;} }; struct SubState2 : public msm::front::state<> , public msm::front::explicit_entry<0> { template <class Event,class FSM> void on_entry(Event const&,FSM& ) {std::cout << "entering: SubFsm2::SubState2" << std::endl;} template <class Event,class FSM> void on_exit(Event const&,FSM& ) {std::cout << "leaving: SubFsm2::SubState2" << std::endl;} }; struct SubState2b : public msm::front::state<> , public msm::front::explicit_entry<1> { template <class Event,class FSM> void on_entry(Event const&,FSM& ) {std::cout << "entering: SubFsm2::SubState2b" << std::endl;} template <class Event,class FSM> void on_exit(Event const&,FSM& ) {std::cout << "leaving: SubFsm2::SubState2b" << std::endl;} }; // test with a pseudo entry struct PseudoEntry1 : public msm::front::entry_pseudo_state<0> { template <class Event,class FSM> void on_entry(Event const&,FSM& ) {std::cout << "entering: SubFsm2::PseudoEntry1" << std::endl;} template <class Event,class FSM> void on_exit(Event const&,FSM& ) {std::cout << "leaving: SubFsm2::PseudoEntry1" << std::endl;} }; struct SubState3 : public msm::front::state<> { template <class Event,class FSM> void on_entry(Event const&,FSM& ) {std::cout << "entering: SubFsm2::SubState3" << std::endl;} template <class Event,class FSM> void on_exit(Event const&,FSM& ) {std::cout << "leaving: SubFsm2::SubState3" << std::endl;} }; struct SubState3b : public msm::front::state<> { template <class Event,class FSM> void on_entry(Event const&,FSM& ) {std::cout << "entering: SubFsm2::SubState3b" << std::endl;} template <class Event,class FSM> void on_exit(Event const&,FSM& ) {std::cout << "leaving: SubFsm2::SubState3b" << std::endl;} }; struct PseudoExit1 : public msm::front::exit_pseudo_state<event6> { template <class Event,class FSM> void on_entry(Event const&,FSM& ) {std::cout << "entering: SubFsm2::PseudoExit1" << std::endl;} template <class Event,class FSM> void on_exit(Event const&,FSM& ) {std::cout << "leaving: SubFsm2::PseudoExit1" << std::endl;} }; // action methods void entry_action(event4 const&) { std::cout << "calling entry_action" << std::endl; } // the initial state. Must be defined typedef mpl::vector<SubState1,SubState1b> initial_state; typedef mpl::vector<SubState2b> explicit_creation; // Transition table for SubFsm2 struct transition_table : mpl::vector< // Start Event Next Action Guard // +--------------+-------------+------------+------------------------+----------------------+ a_row < PseudoEntry1 , event4 , SubState3 ,&SubFsm2_::entry_action >, _row < SubState2 , event6 , SubState1 >, _row < SubState3 , event5 , PseudoExit1 > // +--------------+-------------+------------+------------------------+----------------------+ > {}; // 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; } }; typedef msm::back11::state_machine<SubFsm2_> SubFsm2; // the initial state of the player SM. Must be defined typedef State1 initial_state; // transition actions // guard conditions // Transition table for Fsm struct transition_table : mpl::vector< // Start Event Next Action Guard // +---------------------+--------+------------------------------------+-------+--------+ _row < State1 , event1 , SubFsm2 >, _row < State1 , event2 , SubFsm2::direct<SubFsm2_::SubState2> >, _row < State1 , event3 , mpl::vector<SubFsm2::direct<SubFsm2_::SubState2>, SubFsm2::direct<SubFsm2_::SubState2b> > >, _row < State1 , event4 , SubFsm2::entry_pt <SubFsm2_::PseudoEntry1> >, // +---------------------+--------+------------------------------------+-------+--------+ _row < SubFsm2 , event1 , State1 >, _row < SubFsm2::exit_pt <SubFsm2_::PseudoExit1>, event6 , State2 > // +---------------------+--------+------------------------------------+-------+--------+ > {}; // 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; } }; typedef msm::back11::state_machine<Fsm_> Fsm; // // Testing utilities. // static char const* const state_names[] = { "State1", "SubFsm2","State2" }; void pstate(Fsm const& p) { std::cout << " -> " << state_names[p.current_state()[0]] << std::endl; } void test() { Fsm p; // needed to start the highest-level SM. This will call on_entry and mark the start of the SM p.start(); std::cout << "Simply move in and out of the composite, activate init states" << std::endl; p.process_event(event1()); pstate(p); p.process_event(event1()); pstate(p); std::cout << "Direct entry into SubFsm2::SubState2, then transition to SubState1 and back to State1" << std::endl; p.process_event(event2()); pstate(p); p.process_event(event6()); pstate(p); p.process_event(event1()); pstate(p); std::cout << "processing fork to SubFsm2::SubState2 and SubFsm2::SubState2b" << std::endl; p.process_event(event3()); pstate(p); p.process_event(event1()); pstate(p); std::cout << "processing entry pseudo state" << std::endl; p.process_event(event4()); pstate(p); p.process_event(event1()); pstate(p); std::cout << "processing entry + exit pseudo state" << std::endl; p.process_event(event4()); pstate(p); std::cout << "using exit pseudo state" << std::endl; p.process_event(event5()); pstate(p); } } int main() { test(); return 0; }