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)
BOOST_MSM_EUML_EVENT(end_pause)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" };
pstate(player const & p)109 void pstate(player const& p)
110 {
111 std::cout << " -> " << state_names[p.current_state()[0]] << std::endl;
112 }
113
test()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
main()144 int main()
145 {
146 test();
147 return 0;
148 }
149
150