ceph/src/boost/libs/msm/doc/HTML/examples/CompositeTutorialEuml.cpp

   1 // Copyright 2010 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 #include <vector>
  12 #include <iostream>
  13
  14 #include <boost/msm/back/state_machine.hpp>
  15 #include <boost/msm/front/euml/euml.hpp>
  16
  17 using namespace std;
  18 using namespace boost::msm::front::euml;
  19 namespace msm = boost::msm;
  20
  21 // entry/exit/action/guard logging functors
  22 #include "logging_functors.h"
  23
  24 namespace  // Concrete FSM implementation
  25 {
  26     // events
  27     BOOST_MSM_EUML_EVENT(play)
  28     BOOST_MSM_EUML_EVENT(end_pause)
  29     BOOST_MSM_EUML_EVENT(stop)
  30     BOOST_MSM_EUML_EVENT(pause)
  31     BOOST_MSM_EUML_EVENT(open_close)
  32     BOOST_MSM_EUML_EVENT(next_song)
  33     BOOST_MSM_EUML_EVENT(previous_song)
  34     BOOST_MSM_EUML_EVENT(region2_evt)
  35
  36     // A "complicated" event type that carries some data.
  37     BOOST_MSM_EUML_DECLARE_ATTRIBUTE(std::string,cd_name)
  38     BOOST_MSM_EUML_DECLARE_ATTRIBUTE(DiskTypeEnum,cd_type)
  39     BOOST_MSM_EUML_ATTRIBUTES((attributes_ << cd_name << cd_type ), cd_detected_attributes)
  40     BOOST_MSM_EUML_EVENT_WITH_ATTRIBUTES(cd_detected,cd_detected_attributes)
  41
  42     // Concrete FSM implementation
  43
  44     // The list of FSM states
  45     // state not defining any entry or exit
  46     BOOST_MSM_EUML_STATE((),Paused)
  47     BOOST_MSM_EUML_STATE(( Empty_Entry,Empty_Exit ),Empty)
  48     BOOST_MSM_EUML_STATE(( Open_Entry,Open_Exit ),Open)
  49     BOOST_MSM_EUML_STATE(( Stopped_Entry,Stopped_Exit ),Stopped)
  50
  51
  52     // Playing is now a state machine itself.
  53
  54     // It has 5 substates
  55     BOOST_MSM_EUML_STATE(( Song1_Entry,Song1_Exit ),Song1)
  56     BOOST_MSM_EUML_STATE(( Song2_Entry,Song2_Exit ),Song2)
  57     BOOST_MSM_EUML_STATE(( Song3_Entry,Song3_Exit ),Song3)
  58     BOOST_MSM_EUML_STATE(( Region2State1_Entry,Region2State1_Exit ),Region2State1)
  59     BOOST_MSM_EUML_STATE(( Region2State2_Entry,Region2State2_Exit ),Region2State2)
  60
  61     // Playing has a transition table
  62    BOOST_MSM_EUML_TRANSITION_TABLE((
  63         //  +------------------------------------------------------------------------------+
  64             Song2         == Song1          + next_song       / start_next_song,
  65             Song1         == Song2          + previous_song   / start_prev_song,
  66             Song3         == Song2          + next_song       / start_next_song,
  67             Song2         == Song3          + previous_song   / start_prev_song,
  68             Region2State2 == Region2State1  + region2_evt
  69         //  +------------------------------------------------------------------------------+
  70         ),playing_transition_table )
  71
  72     BOOST_MSM_EUML_DECLARE_STATE_MACHINE( (playing_transition_table, //STT
  73                                         init_ << Song1 << Region2State1 // Init State
  74                                         ),Playing_)
  75     // choice of back-end
  76     typedef msm::back::state_machine<Playing_> Playing_type;
  77     Playing_type const Playing;
  78
  79     // guard conditions
  80     BOOST_MSM_EUML_ACTION(good_disk_format)
  81     {
  82         template <class FSM,class EVT,class SourceState,class TargetState>
  83         bool operator()(EVT const& evt,FSM&,SourceState& ,TargetState& )
  84         {
  85             // to test a guard condition, let's say we understand only CDs, not DVD
  86             if (evt.get_attribute(cd_type)!=DISK_CD)
  87             {
  88                 std::cout << "wrong disk, sorry" << std::endl;
  89                 // just for logging, does not block any transition
  90                 return true;
  91             }
  92             std::cout << "good disk" << std::endl;
  93             return true;
  94         }
  95     };
  96     // replaces the old transition table
  97     BOOST_MSM_EUML_TRANSITION_TABLE((
  98         Playing   == Stopped  + play        / start_playback ,
  99         Playing   == Paused   + end_pause   / resume_playback,
 100         //  +------------------------------------------------------------------------------+
 101         Empty     == Open     + open_close  / close_drawer,
 102         //  +------------------------------------------------------------------------------+
 103         Open      == Empty    + open_close  / open_drawer,
 104         Open      == Paused   + open_close  / stop_and_open,
 105         Open      == Stopped  + open_close  / open_drawer,
 106         Open      == Playing  + open_close  / stop_and_open,
 107         //  +------------------------------------------------------------------------------+
 108         Paused    == Playing  + pause       / pause_playback,
 109         //  +------------------------------------------------------------------------------+
 110         Stopped   == Playing  + stop        / stop_playback,
 111         Stopped   == Paused   + stop        / stop_playback,
 112         Stopped   == Empty    + cd_detected [good_disk_format &&(event_(cd_type)==Int_<DISK_CD>())]
 113                         / (store_cd_info,process_(play)),
 114         Stopped   == Stopped  + stop
 115         //  +------------------------------------------------------------------------------+
 116         ),transition_table)
 117
 118     // create a state machine "on the fly"
 119     BOOST_MSM_EUML_DECLARE_STATE_MACHINE(( transition_table, //STT
 120                                         init_ << Empty, // Init State
 121                                         no_action, // Entry
 122                                         no_action, // Exit
 123                                         attributes_ << no_attributes_, // Attributes
 124                                         configure_ << no_configure_, // configuration
 125                                         Log_No_Transition // no_transition handler
 126                                         ),
 127                                       player_) //fsm name
 128
 129     // choice of back-end
 130     typedef msm::back::state_machine<player_> player;
 131
 132     //
 133     // Testing utilities.
 134     //
 135     static char const* const state_names[] = { "Stopped", "Paused", "Open", "Empty", "Playing" };
 136     void pstate(player const& p)
 137     {
 138         std::cout << " -> " << state_names[p.current_state()[0]] << std::endl;
 139     }
 140
 141     void test()
 142     {
 143         player p;
 144         // needed to start the highest-level SM. This will call on_entry and mark the start of the SM
 145         p.start();
 146         // note that we write open_close and not open_close(), like usual. Both are possible with eUML, but
 147         // you now have less to type.
 148         // go to Open, call on_exit on Empty, then action, then on_entry on Open
 149         p.process_event(open_close); pstate(p);
 150         p.process_event(open_close); pstate(p);
 151         // will be rejected, wrong disk type
 152         p.process_event(
 153             cd_detected("louie, louie",DISK_DVD)); pstate(p);
 154         p.process_event(
 155             cd_detected("louie, louie",DISK_CD)); pstate(p);
 156         // no need to call play() as the previous event does it in its action method
 157         //p.process_event(play);
 158
 159         // make transition happen inside it. Player has no idea about this event but it's ok.
 160         p.process_event(next_song);pstate(p); //2nd song active
 161         p.process_event(next_song);pstate(p);//3rd song active
 162         p.process_event(previous_song);pstate(p);//2nd song active
 163
 164         // at this point, Play is active
 165         p.process_event(pause); pstate(p);
 166
 167         // go back to Playing
 168         p.process_event(end_pause);  pstate(p);
 169         p.process_event(pause); pstate(p);
 170         p.process_event(stop);  pstate(p);
 171
 172         // event leading to the same state
 173         // no action method called as none is defined in the transition table
 174         p.process_event(stop);  pstate(p);
 175     }
 176 }
 177
 178 int main()
 179 {
 180     test();
 181     return 0;
 182 }