1 // Copyright 2008 Christophe Henry 2 // henry UNDERSCORE christophe AT hotmail DOT com 3 // This is an extended version of the state machine available in the boost::mpl library 4 // Distributed under the same license as the original. 5 // Copyright for the original version: 6 // Copyright 2005 David Abrahams and Aleksey Gurtovoy. Distributed 7 // under the Boost Software License, Version 1.0. (See accompanying 8 // file LICENSE_1_0.txt or copy at 9 // http://www.boost.org/LICENSE_1_0.txt) 10 11 #ifndef BOOST_MSM_BACK_FAVOR_COMPILE_TIME_H 12 #define BOOST_MSM_BACK_FAVOR_COMPILE_TIME_H 13 14 #include <utility> 15 #include <deque> 16 17 #include <boost/mpl/filter_view.hpp> 18 #include <boost/mpl/for_each.hpp> 19 #include <boost/mpl/bool.hpp> 20 #include <boost/any.hpp> 21 22 #include <boost/msm/common.hpp> 23 #include <boost/msm/back/metafunctions.hpp> 24 #include <boost/msm/back/common_types.hpp> 25 #include <boost/msm/back/dispatch_table.hpp> 26 27 namespace boost { namespace msm { namespace back 28 { 29 30 template <class Fsm> 31 struct process_any_event_helper 32 { process_any_event_helperboost::msm::back::process_any_event_helper33 process_any_event_helper(msm::back::HandledEnum& res_,Fsm* self_,::boost::any any_event_): 34 res(res_),self(self_),any_event(any_event_),finished(false){} 35 template <class Event> operator ()boost::msm::back::process_any_event_helper36 void operator()(boost::msm::wrap<Event> const&) 37 { 38 if ( ! finished && ::boost::any_cast<Event>(&any_event)!=0) 39 { 40 finished = true; 41 res = self->process_event_internal(::boost::any_cast<Event>(any_event)); 42 } 43 } 44 private: 45 msm::back::HandledEnum& res; 46 Fsm* self; 47 ::boost::any any_event; 48 bool finished; 49 }; 50 51 #define BOOST_MSM_BACK_GENERATE_PROCESS_EVENT(fsmname) \ 52 namespace boost { namespace msm { namespace back{ \ 53 template<> \ 54 ::boost::msm::back::HandledEnum fsmname::process_any_event( ::boost::any const& any_event) \ 55 { \ 56 typedef ::boost::msm::back::recursive_get_transition_table<fsmname>::type stt; \ 57 typedef ::boost::msm::back::generate_event_set<stt>::type stt_events; \ 58 typedef ::boost::msm::back::recursive_get_internal_transition_table<fsmname, ::boost::mpl::true_ >::type istt; \ 59 typedef ::boost::msm::back::generate_event_set<create_real_stt<fsmname,istt>::type >::type istt_events; \ 60 typedef ::boost::msm::back::set_insert_range<stt_events,istt_events>::type all_events; \ 61 ::boost::msm::back::HandledEnum res= ::boost::msm::back::HANDLED_FALSE; \ 62 ::boost::mpl::for_each<all_events, ::boost::msm::wrap< ::boost::mpl::placeholders::_1> > \ 63 (::boost::msm::back::process_any_event_helper<fsmname>(res,this,any_event)); \ 64 return res; \ 65 } \ 66 }}} 67 68 struct favor_compile_time 69 { 70 typedef int compile_policy; 71 typedef ::boost::mpl::false_ add_forwarding_rows; 72 }; 73 74 // Generates a singleton runtime lookup table that maps current state 75 // to a function that makes the SM take its transition on the given 76 // Event type. 77 template <class Fsm,class Stt, class Event> 78 struct dispatch_table < Fsm, Stt, Event, ::boost::msm::back::favor_compile_time> 79 { 80 private: 81 // This is a table of these function pointers. 82 typedef HandledEnum (*cell)(Fsm&, int,int,Event const&); 83 typedef bool (*guard)(Fsm&, Event const&); 84 85 // Compute the maximum state value in the sm so we know how big 86 // to make the table 87 typedef typename generate_state_set<Stt>::type state_list; 88 BOOST_STATIC_CONSTANT(int, max_state = ( ::boost::mpl::size<state_list>::value)); 89 90 struct chain_row 91 { operator ()boost::msm::back::dispatch_table::chain_row92 HandledEnum operator()(Fsm& fsm, int region,int state,Event const& evt) const 93 { 94 HandledEnum res = HANDLED_FALSE; 95 typename std::deque<cell>::const_iterator it = one_state.begin(); 96 while (it != one_state.end() && (res != HANDLED_TRUE && res != HANDLED_DEFERRED )) 97 { 98 HandledEnum handled = (*it)(fsm,region,state,evt); 99 // reject is considered as erasing an error (HANDLED_FALSE) 100 if ((HANDLED_FALSE==handled) && (HANDLED_GUARD_REJECT==res) ) 101 res = HANDLED_GUARD_REJECT; 102 else 103 res = handled; 104 ++it; 105 } 106 return res; 107 } 108 std::deque<cell> one_state; 109 }; 110 template <class TransitionState> call_submachineboost::msm::back::dispatch_table111 static HandledEnum call_submachine(Fsm& fsm, int , int , Event const& evt) 112 { 113 return (fsm.template get_state<TransitionState&>()).process_any_event( ::boost::any(evt)); 114 } 115 // A function object for use with mpl::for_each that stuffs 116 // transitions into cells. 117 struct init_cell 118 { init_cellboost::msm::back::dispatch_table::init_cell119 init_cell(dispatch_table* self_) 120 : self(self_) 121 {} 122 // version for transition event not base of our event 123 template <class Transition> 124 typename ::boost::disable_if< 125 typename ::boost::is_same<typename Transition::current_state_type,Fsm>::type 126 ,void>::type init_event_base_caseboost::msm::back::dispatch_table::init_cell127 init_event_base_case(Transition const&, ::boost::mpl::true_ const &) const 128 { 129 typedef typename create_stt<Fsm>::type stt; 130 BOOST_STATIC_CONSTANT(int, state_id = 131 (get_state_id<stt,typename Transition::current_state_type>::value)); 132 self->entries[state_id+1].one_state.push_front(reinterpret_cast<cell>(&Transition::execute)); 133 } 134 template <class Transition> 135 typename ::boost::enable_if< 136 typename ::boost::is_same<typename Transition::current_state_type,Fsm>::type 137 ,void>::type init_event_base_caseboost::msm::back::dispatch_table::init_cell138 init_event_base_case(Transition const&, ::boost::mpl::true_ const &) const 139 { 140 self->entries[0].one_state.push_front(reinterpret_cast<cell>(&Transition::execute)); 141 } 142 143 // version for transition event base of our event 144 template <class Transition> 145 typename ::boost::disable_if< 146 typename ::boost::is_same<typename Transition::current_state_type,Fsm>::type 147 ,void>::type init_event_base_caseboost::msm::back::dispatch_table::init_cell148 init_event_base_case(Transition const&, ::boost::mpl::false_ const &) const 149 { 150 typedef typename create_stt<Fsm>::type stt; 151 BOOST_STATIC_CONSTANT(int, state_id = 152 (get_state_id<stt,typename Transition::current_state_type>::value)); 153 self->entries[state_id+1].one_state.push_front(&Transition::execute); 154 } 155 template <class Transition> 156 typename ::boost::enable_if< 157 typename ::boost::is_same<typename Transition::current_state_type,Fsm>::type 158 ,void>::type init_event_base_caseboost::msm::back::dispatch_table::init_cell159 init_event_base_case(Transition const&, ::boost::mpl::false_ const &) const 160 { 161 self->entries[0].one_state.push_front(&Transition::execute); 162 } 163 // Cell initializer function object, used with mpl::for_each 164 template <class Transition> 165 typename ::boost::enable_if<typename has_not_real_row_tag<Transition>::type,void >::type operator ()boost::msm::back::dispatch_table::init_cell166 operator()(Transition const&,boost::msm::back::dummy<0> = 0) const 167 { 168 // version for not real rows. No problem because irrelevant for process_event 169 } 170 template <class Transition> 171 typename ::boost::disable_if<typename has_not_real_row_tag<Transition>::type,void >::type operator ()boost::msm::back::dispatch_table::init_cell172 operator()(Transition const& tr,boost::msm::back::dummy<1> = 0) const 173 { 174 //only if the transition event is a base of our event is the reinterpret_case safe 175 init_event_base_case(tr, 176 ::boost::mpl::bool_< 177 ::boost::is_base_of<typename Transition::transition_event,Event>::type::value>() ); 178 } 179 180 dispatch_table* self; 181 }; 182 183 // Cell default-initializer function object, used with mpl::for_each 184 // initializes with call_no_transition, defer_transition or default_eventless_transition 185 // variant for non-anonymous transitions 186 template <class EventType,class Enable=void> 187 struct default_init_cell 188 { default_init_cellboost::msm::back::dispatch_table::default_init_cell189 default_init_cell(dispatch_table* self_,chain_row* tofill_entries_) 190 : self(self_),tofill_entries(tofill_entries_) 191 {} 192 template <bool deferred,bool composite, int some_dummy=0> 193 struct helper 194 {}; 195 template <int some_dummy> struct helper<true,false,some_dummy> 196 { 197 template <class State> executeboost::msm::back::dispatch_table::default_init_cell::helper198 static void execute(boost::msm::wrap<State> const&,chain_row* tofill) 199 { 200 typedef typename create_stt<Fsm>::type stt; 201 BOOST_STATIC_CONSTANT(int, state_id = (get_state_id<stt,State>::value)); 202 cell call_no_transition = &Fsm::defer_transition; 203 tofill[state_id+1].one_state.push_back(call_no_transition); 204 } 205 }; 206 template <int some_dummy> struct helper<true,true,some_dummy> 207 { 208 template <class State> executeboost::msm::back::dispatch_table::default_init_cell::helper209 static void execute(boost::msm::wrap<State> const&,chain_row* tofill) 210 { 211 typedef typename create_stt<Fsm>::type stt; 212 BOOST_STATIC_CONSTANT(int, state_id = (get_state_id<stt,State>::value)); 213 cell call_no_transition = &Fsm::defer_transition; 214 tofill[state_id+1].one_state.push_back(call_no_transition); 215 } 216 }; 217 template <int some_dummy> struct helper<false,true,some_dummy> 218 { 219 template <class State> 220 static 221 typename ::boost::enable_if< 222 typename ::boost::is_same<State,Fsm>::type 223 ,void>::type executeboost::msm::back::dispatch_table::default_init_cell::helper224 execute(boost::msm::wrap<State> const&,chain_row* tofill,boost::msm::back::dummy<0> = 0) 225 { 226 // for internal tables 227 cell call_no_transition_internal = &Fsm::call_no_transition; 228 tofill[0].one_state.push_front(call_no_transition_internal); 229 } 230 template <class State> 231 static 232 typename ::boost::disable_if< 233 typename ::boost::is_same<State,Fsm>::type 234 ,void>::type executeboost::msm::back::dispatch_table::default_init_cell::helper235 execute(boost::msm::wrap<State> const&,chain_row* tofill,boost::msm::back::dummy<1> = 0) 236 { 237 typedef typename create_stt<Fsm>::type stt; 238 BOOST_STATIC_CONSTANT(int, state_id = (get_state_id<stt,State>::value)); 239 cell call_no_transition = &call_submachine< State >; 240 tofill[state_id+1].one_state.push_front(call_no_transition); 241 } 242 }; 243 template <int some_dummy> struct helper<false,false,some_dummy> 244 { 245 template <class State> executeboost::msm::back::dispatch_table::default_init_cell::helper246 static void execute(boost::msm::wrap<State> const&,chain_row* tofill) 247 { 248 typedef typename create_stt<Fsm>::type stt; 249 BOOST_STATIC_CONSTANT(int, state_id = (get_state_id<stt,State>::value)); 250 cell call_no_transition = &Fsm::call_no_transition; 251 tofill[state_id+1].one_state.push_back(call_no_transition); 252 } 253 }; 254 template <class State> operator ()boost::msm::back::dispatch_table::default_init_cell255 void operator()(boost::msm::wrap<State> const& s) 256 { 257 helper<has_state_delayed_event<State,Event>::type::value, 258 is_composite_state<State>::type::value>::execute(s,tofill_entries); 259 } 260 dispatch_table* self; 261 chain_row* tofill_entries; 262 }; 263 264 // variant for anonymous transitions 265 template <class EventType> 266 struct default_init_cell<EventType, 267 typename ::boost::enable_if< 268 typename is_completion_event<EventType>::type>::type> 269 { default_init_cellboost::msm::back::dispatch_table::default_init_cell270 default_init_cell(dispatch_table* self_,chain_row* tofill_entries_) 271 : self(self_),tofill_entries(tofill_entries_) 272 {} 273 274 // this event is a compound one (not a real one, just one for use in event-less transitions) 275 // Note this event cannot be used as deferred! 276 template <class State> operator ()boost::msm::back::dispatch_table::default_init_cell277 void operator()(boost::msm::wrap<State> const&) 278 { 279 typedef typename create_stt<Fsm>::type stt; 280 BOOST_STATIC_CONSTANT(int, state_id = (get_state_id<stt,State>::value)); 281 cell call_no_transition = &Fsm::default_eventless_transition; 282 tofill_entries[state_id+1].one_state.push_back(call_no_transition); 283 } 284 285 dispatch_table* self; 286 chain_row* tofill_entries; 287 }; 288 289 public: 290 // initialize the dispatch table for a given Event and Fsm dispatch_tableboost::msm::back::dispatch_table291 dispatch_table() 292 { 293 // Initialize cells for no transition 294 ::boost::mpl::for_each< 295 ::boost::mpl::filter_view< 296 Stt, ::boost::is_base_of<transition_event< ::boost::mpl::placeholders::_>, Event> > > 297 (init_cell(this)); 298 299 ::boost::mpl::for_each< 300 typename generate_state_set<Stt>::type, 301 boost::msm::wrap< ::boost::mpl::placeholders::_1> > 302 (default_init_cell<Event>(this,entries)); 303 304 } 305 306 // The singleton instance. 307 static const dispatch_table instance; 308 309 public: // data members 310 chain_row entries[max_state+1]; 311 }; 312 313 template <class Fsm,class Stt, class Event> 314 const boost::msm::back::dispatch_table<Fsm,Stt, Event,favor_compile_time> 315 dispatch_table<Fsm,Stt, Event,favor_compile_time>::instance; 316 317 }}} // boost::msm::back 318 319 #endif //BOOST_MSM_BACK_FAVOR_COMPILE_TIME_H 320