ceph/src/boost/libs/msm/doc/HTML/examples/SimpleTutorialEuml2.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     // note that unlike the SimpleTutorial, events must derive from euml_event.
  28     BOOST_MSM_EUML_EVENT(play)
  29     BOOST_MSM_EUML_EVENT(end_pause)
  30     BOOST_MSM_EUML_EVENT(stop)
  31     BOOST_MSM_EUML_EVENT(pause)
  32     BOOST_MSM_EUML_EVENT(open_close)
  33
  34     // A "complicated" event type that carries some data.
  35     BOOST_MSM_EUML_DECLARE_ATTRIBUTE(std::string,cd_name)
  36     BOOST_MSM_EUML_DECLARE_ATTRIBUTE(DiskTypeEnum,cd_type)
  37     BOOST_MSM_EUML_ATTRIBUTES((attributes_ << cd_name << cd_type ), cd_detected_attributes)
  38     BOOST_MSM_EUML_EVENT_WITH_ATTRIBUTES(cd_detected,cd_detected_attributes)
  39
  40     // Concrete FSM implementation
  41
  42     // The list of FSM states
  43
  44     // state not needing any entry or exit
  45     BOOST_MSM_EUML_STATE((),Paused)
  46     BOOST_MSM_EUML_STATE(( Empty_Entry,Empty_Exit ),Empty)
  47     BOOST_MSM_EUML_STATE(( Open_Entry,Open_Exit ),Open)
  48     BOOST_MSM_EUML_STATE(( Stopped_Entry,Stopped_Exit ),Stopped)
  49     BOOST_MSM_EUML_STATE(( Playing_Entry,Playing_Exit ),Playing)
  50
  51     // guard conditions
  52     BOOST_MSM_EUML_ACTION(good_disk_format)
  53     {
  54         template <class FSM,class EVT,class SourceState,class TargetState>
  55         bool operator()(EVT const& evt,FSM&,SourceState& ,TargetState& )
  56         {
  57             // to test a guard condition, let's say we understand only CDs, not DVD
  58             if (evt.get_attribute(cd_type)!=DISK_CD)
  59             {
  60                 std::cout << "wrong disk, sorry" << std::endl;
  61                 // just for logging, does not block any transition
  62                 return true;
  63             }
  64             std::cout << "good disk" << std::endl;
  65             return true;
  66         }
  67     };
  68     // replaces the old transition table
  69     BOOST_MSM_EUML_TRANSITION_TABLE((
  70           Stopped + play        / start_playback  == Playing                        ,
  71           Stopped + open_close  / open_drawer     == Open                           ,
  72           Stopped + stop                          == Stopped,
  73           //  +------------------------------------------------------------------------------+
  74           Open    + open_close  / close_drawer    == Empty                          ,
  75           //  +------------------------------------------------------------------------------+
  76           Empty   + open_close  / open_drawer     == Open                           ,
  77           Empty   + cd_detected
  78             [good_disk_format &&(event_(cd_type)==Int_<DISK_CD>())]
  79             / (store_cd_info,process_(play))      == Stopped                        ,
  80          //  +------------------------------------------------------------------------------+
  81           Playing + stop        / stop_playback   == Stopped                        ,
  82           Playing + pause       / pause_playback  == Paused                         ,
  83           Playing + open_close  / stop_and_open   == Open                           ,
  84           //  +------------------------------------------------------------------------------+
  85           Paused  + end_pause   / resume_playback == Playing                        ,
  86           Paused  + stop        / stop_playback   == Stopped                        ,
  87           Paused  + open_close  / stop_and_open   == Open
  88           //  +------------------------------------------------------------------------------+
  89           ),transition_table)
  90
  91     // create a state machine "on the fly"
  92     BOOST_MSM_EUML_DECLARE_STATE_MACHINE(( transition_table, //STT
  93                                     init_ << Empty, // Init State
  94                                     no_action, // Entry
  95                                     no_action, // Exit
  96                                     attributes_ << no_attributes_, // Attributes
  97                                     configure_ << no_configure_, // configuration
  98                                     Log_No_Transition // no_transition handler
  99                                     ),
 100                                   player_) //fsm name
 101
 102     // choice of back-end
 103     typedef msm::back::state_machine<player_> player;
 104
 105     //
 106     // Testing utilities.
 107     //
 108     static char const* const state_names[] = { "Stopped", "Open", "Empty", "Playing", "Paused" };
 109     void pstate(player const& p)
 110     {
 111         std::cout << " -> " << state_names[p.current_state()[0]] << std::endl;
 112     }
 113
 114     void test()
 115     {
 116         player p;
 117         // needed to start the highest-level SM. This will call on_entry and mark the start of the SM
 118         p.start();
 119         // go to Open, call on_exit on Empty, then action, then on_entry on Open
 120         p.process_event(open_close); pstate(p);
 121         p.process_event(open_close); pstate(p);
 122         // will be rejected, wrong disk type
 123         p.process_event(
 124             cd_detected("louie, louie",DISK_DVD)); pstate(p);
 125         p.process_event(
 126             cd_detected("louie, louie",DISK_CD)); pstate(p);
 127         // no need to call play as the previous event does it in its action method
 128         //p.process_event(play);
 129
 130         // at this point, Play is active
 131         p.process_event(pause); pstate(p);
 132         // go back to Playing
 133         p.process_event(end_pause);  pstate(p);
 134         p.process_event(pause); pstate(p);
 135         p.process_event(stop);  pstate(p);
 136         // event leading to the same state
 137         // no action method called as none is defined in the transition table
 138         p.process_event(stop);  pstate(p);
 139         // test call to no_transition
 140         p.process_event(pause); pstate(p);
 141     }
 142 }
 143
 144 int main()
 145 {
 146     test();
 147     return 0;
 148 }
 149