ceph/src/boost/libs/msm/include/boost/msm/front/states.hpp

   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_FRONT_STATES_H
  12 #define BOOST_MSM_FRONT_STATES_H
  13
  14 #include <boost/mpl/bool.hpp>
  15 #include <boost/mpl/vector.hpp>
  16 #include <boost/msm/front/common_states.hpp>
  17 #include <boost/msm/row_tags.hpp>
  18 #include <boost/msm/back/metafunctions.hpp>
  19
  20 namespace boost { namespace msm { namespace front
  21 {
  22
  23 struct no_sm_ptr
  24 {
  25     // tags
  26     typedef ::boost::mpl::bool_<false>   needs_sm;
  27 };
  28 struct sm_ptr
  29 {
  30     // tags
  31     typedef ::boost::mpl::bool_<true>    needs_sm;
  32 };
  33 // kept for backward compatibility
  34 struct NoSMPtr
  35 {
  36     // tags
  37     typedef ::boost::mpl::bool_<false>   needs_sm;
  38 };
  39 struct SMPtr
  40 {
  41     // tags
  42     typedef ::boost::mpl::bool_<true>    needs_sm;
  43 };
  44
  45 // provides the typedefs and interface. Concrete states derive from it.
  46 // template argument: pointer-to-fsm policy
  47 template<class BASE = default_base_state,class SMPtrPolicy = no_sm_ptr>
  48 struct state :  public boost::msm::front::detail::state_base<BASE>, SMPtrPolicy
  49 {
  50     // tags
  51     // default: no flag
  52     typedef ::boost::mpl::vector0<>       flag_list;
  53     typedef ::boost::mpl::vector0<>       internal_flag_list;
  54     //default: no deferred events
  55     typedef ::boost::mpl::vector0<>       deferred_events;
  56 };
  57
  58 // terminate state simply defines the TerminateFlag flag
  59 // template argument: pointer-to-fsm policy
  60 template<class BASE = default_base_state,class SMPtrPolicy = no_sm_ptr>
  61 struct terminate_state : public boost::msm::front::detail::state_base<BASE>, SMPtrPolicy
  62 {
  63     // tags
  64     typedef ::boost::mpl::vector0<>                               flag_list;
  65     typedef ::boost::mpl::vector< boost::msm::TerminateFlag>      internal_flag_list;
  66     //default: no deferred events
  67     typedef ::boost::mpl::vector0<>                               deferred_events;
  68 };
  69
  70 // terminate state simply defines the InterruptedFlag and EndInterruptFlag<EndInterruptEvent> flags
  71 // template argument: event which ends the interrupt
  72 // template argument: pointer-to-fsm policy
  73 template <class EndInterruptEvent,class BASE = default_base_state,class SMPtrPolicy = no_sm_ptr>
  74 struct interrupt_state : public boost::msm::front::detail::state_base<BASE>, SMPtrPolicy
  75 {
  76     // tags
  77     typedef ::boost::mpl::vector0<>                           flag_list;
  78     typedef typename boost::msm::back::build_interrupt_state_flag_list<
  79         typename boost::msm::back::get_interrupt_events<EndInterruptEvent>::type
  80     >::type internal_flag_list;
  81
  82     //default: no deferred events
  83     typedef ::boost::mpl::vector0<>                           deferred_events;
  84 };
  85
  86 // not a state but a bunch of extra typedefs to handle direct entry into a composite state. To be derived from
  87 // template argument: zone index of this state
  88 template <int ZoneIndex=-1>
  89 struct explicit_entry
  90 {
  91     typedef int explicit_entry_state;
  92     enum {zone_index=ZoneIndex};
  93 };
  94
  95 // to be derived from. Makes a type an entry (pseudo) state. Actually an almost full-fledged state
  96 // template argument: containing composite
  97 // template argument: zone index of this state
  98 // template argument: pointer-to-fsm policy
  99 template<int ZoneIndex=-1,class BASE = default_base_state,class SMPtrPolicy = no_sm_ptr>
 100 struct entry_pseudo_state
 101     :  public boost::msm::front::detail::state_base<BASE>,SMPtrPolicy
 102 {
 103     // tags
 104     typedef int                          pseudo_entry;
 105     enum {zone_index=ZoneIndex};
 106     typedef int explicit_entry_state;
 107     // default: no flag
 108     typedef ::boost::mpl::vector0<>       flag_list;
 109     typedef ::boost::mpl::vector0<>       internal_flag_list;
 110     //default: no deferred events
 111     typedef ::boost::mpl::vector0<>       deferred_events;
 112 };
 113
 114 // to be derived from. Makes a state an exit (pseudo) state. Actually an almost full-fledged state
 115 // template argument: event to forward
 116 // template argument: pointer-to-fsm policy
 117 template<class Event,class BASE = default_base_state,class SMPtrPolicy = no_sm_ptr>
 118 struct exit_pseudo_state : public boost::msm::front::detail::state_base<BASE> , SMPtrPolicy
 119 {
 120     typedef Event       event;
 121     typedef BASE        Base;
 122     typedef SMPtrPolicy PtrPolicy;
 123     typedef int         pseudo_exit;
 124
 125     // default: no flag
 126     typedef ::boost::mpl::vector0<>  flag_list;
 127     typedef ::boost::mpl::vector0<>  internal_flag_list;
 128     //default: no deferred events
 129     typedef ::boost::mpl::vector0<>  deferred_events;
 130 };
 131
 132 }}}
 133
 134 #endif //BOOST_MSM_FRONT_STATES_H
 135