// Copyright 2008 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)
#ifndef BOOST_MSM_BACK_FAVOR_COMPILE_TIME_H
#define BOOST_MSM_BACK_FAVOR_COMPILE_TIME_H
#include <utility>
#include <deque>
#include <boost/mpl/filter_view.hpp>
#include <boost/mpl/for_each.hpp>
#include <boost/mpl/bool.hpp>
#include <boost/any.hpp>
#include <boost/msm/common.hpp>
#include <boost/msm/back/metafunctions.hpp>
#include <boost/msm/back/common_types.hpp>
#include <boost/msm/back/dispatch_table.hpp>
namespace boost { namespace msm { namespace back
{
template <class Fsm>
struct process_any_event_helper
{
process_any_event_helper(msm::back::HandledEnum& res_,Fsm* self_,::boost::any any_event_):
res(res_),self(self_),any_event(any_event_),finished(false){}
template <class Event>
void operator()(boost::msm::wrap<Event> const&)
{
if ( ! finished && ::boost::any_cast<Event>(&any_event)!=0)
{
finished = true;
res = self->process_event_internal(::boost::any_cast<Event>(any_event));
}
}
private:
msm::back::HandledEnum& res;
Fsm* self;
::boost::any any_event;
bool finished;
};
#define BOOST_MSM_BACK_GENERATE_PROCESS_EVENT(fsmname) \
namespace boost { namespace msm { namespace back{ \
template<> \
::boost::msm::back::HandledEnum fsmname::process_any_event( ::boost::any const& any_event) \
{ \
typedef ::boost::msm::back::recursive_get_transition_table<fsmname>::type stt; \
typedef ::boost::msm::back::generate_event_set<stt>::type stt_events; \
typedef ::boost::msm::back::recursive_get_internal_transition_table<fsmname, ::boost::mpl::true_ >::type istt; \
typedef ::boost::msm::back::generate_event_set<create_real_stt<fsmname,istt>::type >::type istt_events; \
typedef ::boost::msm::back::set_insert_range<stt_events,istt_events>::type all_events; \
::boost::msm::back::HandledEnum res= ::boost::msm::back::HANDLED_FALSE; \
::boost::mpl::for_each<all_events, ::boost::msm::wrap< ::boost::mpl::placeholders::_1> > \
(::boost::msm::back::process_any_event_helper<fsmname>(res,this,any_event)); \
return res; \
} \
}}}
struct favor_compile_time
{
typedef int compile_policy;
typedef ::boost::mpl::false_ add_forwarding_rows;
};
// Generates a singleton runtime lookup table that maps current state
// to a function that makes the SM take its transition on the given
// Event type.
template <class Fsm,class Stt, class Event>
struct dispatch_table < Fsm, Stt, Event, ::boost::msm::back::favor_compile_time>
{
private:
// This is a table of these function pointers.
typedef HandledEnum (*cell)(Fsm&, int,int,Event const&);
typedef bool (*guard)(Fsm&, Event const&);
// Compute the maximum state value in the sm so we know how big
// to make the table
typedef typename generate_state_set<Stt>::type state_list;
BOOST_STATIC_CONSTANT(int, max_state = ( ::boost::mpl::size<state_list>::value));
struct chain_row
{
HandledEnum operator()(Fsm& fsm, int region,int state,Event const& evt) const
{
HandledEnum res = HANDLED_FALSE;
typename std::deque<cell>::const_iterator it = one_state.begin();
while (it != one_state.end() && (res != HANDLED_TRUE && res != HANDLED_DEFERRED ))
{
HandledEnum handled = (*it)(fsm,region,state,evt);
// reject is considered as erasing an error (HANDLED_FALSE)
if ((HANDLED_FALSE==handled) && (HANDLED_GUARD_REJECT==res) )
res = HANDLED_GUARD_REJECT;
else
res = handled;
++it;
}
return res;
}
std::deque<cell> one_state;
};
template <class TransitionState>
static HandledEnum call_submachine(Fsm& fsm, int , int , Event const& evt)
{
return (fsm.template get_state<TransitionState&>()).process_any_event( ::boost::any(evt));
}
// A function object for use with mpl::for_each that stuffs
// transitions into cells.
struct init_cell
{
init_cell(dispatch_table* self_)
: self(self_)
{}
// version for transition event not base of our event
template <class Transition>
typename ::boost::disable_if<
typename ::boost::is_same<typename Transition::current_state_type,Fsm>::type
,void>::type
init_event_base_case(Transition const&, ::boost::mpl::true_ const &) const
{
typedef typename create_stt<Fsm>::type stt;
BOOST_STATIC_CONSTANT(int, state_id =
(get_state_id<stt,typename Transition::current_state_type>::value));
self->entries[state_id+1].one_state.push_front(reinterpret_cast<cell>(&Transition::execute));
}
template <class Transition>
typename ::boost::enable_if<
typename ::boost::is_same<typename Transition::current_state_type,Fsm>::type
,void>::type
init_event_base_case(Transition const&, ::boost::mpl::true_ const &) const
{
self->entries[0].one_state.push_front(reinterpret_cast<cell>(&Transition::execute));
}
// version for transition event base of our event
template <class Transition>
typename ::boost::disable_if<
typename ::boost::is_same<typename Transition::current_state_type,Fsm>::type
,void>::type
init_event_base_case(Transition const&, ::boost::mpl::false_ const &) const
{
typedef typename create_stt<Fsm>::type stt;
BOOST_STATIC_CONSTANT(int, state_id =
(get_state_id<stt,typename Transition::current_state_type>::value));
self->entries[state_id+1].one_state.push_front(&Transition::execute);
}
template <class Transition>
typename ::boost::enable_if<
typename ::boost::is_same<typename Transition::current_state_type,Fsm>::type
,void>::type
init_event_base_case(Transition const&, ::boost::mpl::false_ const &) const
{
self->entries[0].one_state.push_front(&Transition::execute);
}
// Cell initializer function object, used with mpl::for_each
template <class Transition>
typename ::boost::enable_if<typename has_not_real_row_tag<Transition>::type,void >::type
operator()(Transition const&,boost::msm::back::dummy<0> = 0) const
{
// version for not real rows. No problem because irrelevant for process_event
}
template <class Transition>
typename ::boost::disable_if<typename has_not_real_row_tag<Transition>::type,void >::type
operator()(Transition const& tr,boost::msm::back::dummy<1> = 0) const
{
//only if the transition event is a base of our event is the reinterpret_case safe
init_event_base_case(tr,
::boost::mpl::bool_<
::boost::is_base_of<typename Transition::transition_event,Event>::type::value>() );
}
dispatch_table* self;
};
// Cell default-initializer function object, used with mpl::for_each
// initializes with call_no_transition, defer_transition or default_eventless_transition
// variant for non-anonymous transitions
template <class EventType,class Enable=void>
struct default_init_cell
{
default_init_cell(dispatch_table* self_,chain_row* tofill_entries_)
: self(self_),tofill_entries(tofill_entries_)
{}
template <bool deferred,bool composite, int some_dummy=0>
struct helper
{};
template <int some_dummy> struct helper<true,false,some_dummy>
{
template <class State>
static void execute(boost::msm::wrap<State> const&,chain_row* tofill)
{
typedef typename create_stt<Fsm>::type stt;
BOOST_STATIC_CONSTANT(int, state_id = (get_state_id<stt,State>::value));
cell call_no_transition = &Fsm::defer_transition;
tofill[state_id+1].one_state.push_back(call_no_transition);
}
};
template <int some_dummy> struct helper<true,true,some_dummy>
{
template <class State>
static void execute(boost::msm::wrap<State> const&,chain_row* tofill)
{
typedef typename create_stt<Fsm>::type stt;
BOOST_STATIC_CONSTANT(int, state_id = (get_state_id<stt,State>::value));
cell call_no_transition = &Fsm::defer_transition;
tofill[state_id+1].one_state.push_back(call_no_transition);
}
};
template <int some_dummy> struct helper<false,true,some_dummy>
{
template <class State>
static
typename ::boost::enable_if<
typename ::boost::is_same<State,Fsm>::type
,void>::type
execute(boost::msm::wrap<State> const&,chain_row* tofill,boost::msm::back::dummy<0> = 0)
{
// for internal tables
cell call_no_transition_internal = &Fsm::call_no_transition;
tofill[0].one_state.push_front(call_no_transition_internal);
}
template <class State>
static
typename ::boost::disable_if<
typename ::boost::is_same<State,Fsm>::type
,void>::type
execute(boost::msm::wrap<State> const&,chain_row* tofill,boost::msm::back::dummy<1> = 0)
{
typedef typename create_stt<Fsm>::type stt;
BOOST_STATIC_CONSTANT(int, state_id = (get_state_id<stt,State>::value));
cell call_no_transition = &call_submachine< State >;
tofill[state_id+1].one_state.push_front(call_no_transition);
}
};
template <int some_dummy> struct helper<false,false,some_dummy>
{
template <class State>
static void execute(boost::msm::wrap<State> const&,chain_row* tofill)
{
typedef typename create_stt<Fsm>::type stt;
BOOST_STATIC_CONSTANT(int, state_id = (get_state_id<stt,State>::value));
cell call_no_transition = &Fsm::call_no_transition;
tofill[state_id+1].one_state.push_back(call_no_transition);
}
};
template <class State>
void operator()(boost::msm::wrap<State> const& s)
{
helper<has_state_delayed_event<State,Event>::type::value,
is_composite_state<State>::type::value>::execute(s,tofill_entries);
}
dispatch_table* self;
chain_row* tofill_entries;
};
// variant for anonymous transitions
template <class EventType>
struct default_init_cell<EventType,
typename ::boost::enable_if<
typename is_completion_event<EventType>::type>::type>
{
default_init_cell(dispatch_table* self_,chain_row* tofill_entries_)
: self(self_),tofill_entries(tofill_entries_)
{}
// this event is a compound one (not a real one, just one for use in event-less transitions)
// Note this event cannot be used as deferred!
template <class State>
void operator()(boost::msm::wrap<State> const&)
{
typedef typename create_stt<Fsm>::type stt;
BOOST_STATIC_CONSTANT(int, state_id = (get_state_id<stt,State>::value));
cell call_no_transition = &Fsm::default_eventless_transition;
tofill_entries[state_id+1].one_state.push_back(call_no_transition);
}
dispatch_table* self;
chain_row* tofill_entries;
};
public:
// initialize the dispatch table for a given Event and Fsm
dispatch_table()
{
// Initialize cells for no transition
::boost::mpl::for_each<
::boost::mpl::filter_view<
Stt, ::boost::is_base_of<transition_event< ::boost::mpl::placeholders::_>, Event> > >
(init_cell(this));
::boost::mpl::for_each<
typename generate_state_set<Stt>::type,
boost::msm::wrap< ::boost::mpl::placeholders::_1> >
(default_init_cell<Event>(this,entries));
}
// The singleton instance.
static const dispatch_table instance;
public: // data members
chain_row entries[max_state+1];
};
template <class Fsm,class Stt, class Event>
const boost::msm::back::dispatch_table<Fsm,Stt, Event,favor_compile_time>
dispatch_table<Fsm,Stt, Event,favor_compile_time>::instance;
}}} // boost::msm::back
#endif //BOOST_MSM_BACK_FAVOR_COMPILE_TIME_H