deps/boost_1_63_0/boost/statechart/detail/node_state.hpp

   1 #ifndef BOOST_STATECHART_DETAIL_NODE_STATE_HPP_INCLUDED
   2 #define BOOST_STATECHART_DETAIL_NODE_STATE_HPP_INCLUDED
   3 //////////////////////////////////////////////////////////////////////////////
   4 // Copyright 2002-2006 Andreas Huber Doenni
   5 // Distributed under the Boost Software License, Version 1.0. (See accompany-
   6 // ing file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   7 //////////////////////////////////////////////////////////////////////////////
   8
   9
  10
  11 #include <boost/statechart/detail/state_base.hpp>
  12
  13 #include <boost/intrusive_ptr.hpp>
  14 #include <boost/assert.hpp>  // BOOST_ASSERT
  15
  16 #include <algorithm> // std::find_if
  17
  18
  19
  20 namespace boost
  21 {
  22 namespace statechart
  23 {
  24 namespace detail
  25 {
  26
  27
  28
  29 template< class Allocator, class RttiPolicy >
  30 class node_state_base : public state_base< Allocator, RttiPolicy >
  31 {
  32   typedef state_base< Allocator, RttiPolicy > base_type;
  33   protected:
  34     //////////////////////////////////////////////////////////////////////////
  35     node_state_base( typename RttiPolicy::id_provider_type idProvider ) :
  36       base_type( idProvider )
  37     {
  38     }
  39
  40     ~node_state_base() {}
  41
  42   public:
  43     //////////////////////////////////////////////////////////////////////////
  44     // The following declarations should be private.
  45     // They are only public because many compilers lack template friends.
  46     //////////////////////////////////////////////////////////////////////////
  47     typedef base_type state_base_type;
  48     typedef intrusive_ptr< node_state_base > direct_state_base_ptr_type;
  49     virtual void exit_impl(
  50       direct_state_base_ptr_type & pSelf,
  51       typename base_type::node_state_base_ptr_type & pOutermostUnstableState,
  52       bool performFullExit ) = 0;
  53 };
  54
  55 //////////////////////////////////////////////////////////////////////////////
  56 template< class OrthogonalRegionCount, class Allocator, class RttiPolicy >
  57 class node_state : public node_state_base< Allocator, RttiPolicy >
  58 {
  59   typedef node_state_base< Allocator, RttiPolicy > base_type;
  60   protected:
  61     //////////////////////////////////////////////////////////////////////////
  62     node_state( typename RttiPolicy::id_provider_type idProvider ) :
  63       base_type( idProvider )
  64     {
  65       for ( orthogonal_position_type pos = 0;
  66             pos < OrthogonalRegionCount::value; ++pos )
  67       {
  68         pInnerStates[ pos ] = 0;
  69       }
  70     }
  71
  72     ~node_state() {}
  73
  74   public:
  75     //////////////////////////////////////////////////////////////////////////
  76     // The following declarations should be private.
  77     // They are only public because many compilers lack template friends.
  78     //////////////////////////////////////////////////////////////////////////
  79     typedef typename base_type::state_base_type state_base_type;
  80
  81     void add_inner_state( orthogonal_position_type position,
  82                           state_base_type * pInnerState )
  83     {
  84       BOOST_ASSERT( ( position < OrthogonalRegionCount::value ) &&
  85                     ( pInnerStates[ position ] == 0 ) );
  86       pInnerStates[ position ] = pInnerState;
  87     }
  88
  89     void remove_inner_state( orthogonal_position_type position )
  90     {
  91       BOOST_ASSERT( position < OrthogonalRegionCount::value );
  92       pInnerStates[ position ] = 0;
  93     }
  94
  95     virtual void remove_from_state_list(
  96       typename state_base_type::state_list_type::iterator & statesEnd,
  97       typename state_base_type::node_state_base_ptr_type &
  98         pOutermostUnstableState,
  99       bool performFullExit )
 100     {
 101       state_base_type ** const pPastEnd =
 102         &pInnerStates[ OrthogonalRegionCount::value ];
 103       // We must not iterate past the last inner state because *this* state
 104       // will no longer exist when the last inner state has been removed
 105       state_base_type ** const pFirstNonNull = std::find_if(
 106         &pInnerStates[ 0 ], pPastEnd, &node_state::is_not_null );
 107
 108       if ( pFirstNonNull == pPastEnd )
 109       {
 110         // The state does not have inner states but is still alive, this must
 111         // be the outermost unstable state then.
 112         BOOST_ASSERT( get_pointer( pOutermostUnstableState ) == this );
 113         typename state_base_type::node_state_base_ptr_type pSelf =
 114           pOutermostUnstableState;
 115         pSelf->exit_impl( pSelf, pOutermostUnstableState, performFullExit );
 116       }
 117       else
 118       {
 119         // Destroy inner states in the reverse order of construction
 120         for ( state_base_type ** pState = pPastEnd; pState != pFirstNonNull; )
 121         {
 122           --pState;
 123
 124           // An inner orthogonal state might have been terminated long before,
 125           // that's why we have to check for 0 pointers
 126           if ( *pState != 0 )
 127           {
 128             ( *pState )->remove_from_state_list(
 129               statesEnd, pOutermostUnstableState, performFullExit );
 130           }
 131         }
 132       }
 133     }
 134
 135     typedef typename base_type::direct_state_base_ptr_type
 136       direct_state_base_ptr_type;
 137
 138   private:
 139     //////////////////////////////////////////////////////////////////////////
 140     static bool is_not_null( const state_base_type * pInner )
 141     {
 142       return pInner != 0;
 143     }
 144
 145     state_base_type * pInnerStates[ OrthogonalRegionCount::value ];
 146 };
 147
 148
 149
 150 } // namespace detail
 151 } // namespace statechart
 152 } // namespace boost
 153
 154
 155
 156 #endif