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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 | using namespace boost::msm::front; | |
20 | namespace msm = boost::msm; | |
21 | ||
22 | // entry/exit/action/guard logging functors | |
23 | #include "logging_functors.h" | |
24 | ||
25 | namespace // Concrete FSM implementation | |
26 | { | |
27 | // events | |
28 | // note that unlike the SimpleTutorial, events must derive from euml_event. | |
29 | BOOST_MSM_EUML_EVENT(play) | |
30 | BOOST_MSM_EUML_EVENT(end_pause) | |
31 | BOOST_MSM_EUML_EVENT(stop) | |
32 | BOOST_MSM_EUML_EVENT(pause) | |
33 | BOOST_MSM_EUML_EVENT(open_close) | |
34 | BOOST_MSM_EUML_EVENT(internal_event) | |
35 | BOOST_MSM_EUML_EVENT(next_song) | |
36 | BOOST_MSM_EUML_EVENT(previous_song) | |
37 | ||
38 | // A "complicated" event type that carries some data. | |
39 | BOOST_MSM_EUML_DECLARE_ATTRIBUTE(std::string,cd_name) | |
40 | BOOST_MSM_EUML_DECLARE_ATTRIBUTE(DiskTypeEnum,cd_type) | |
41 | BOOST_MSM_EUML_ATTRIBUTES((attributes_ << cd_name << cd_type ), cd_detected_attributes) | |
42 | BOOST_MSM_EUML_EVENT_WITH_ATTRIBUTES(cd_detected,cd_detected_attributes) | |
43 | ||
44 | // Concrete FSM implementation | |
45 | ||
46 | // The list of FSM states | |
47 | BOOST_MSM_EUML_STATE(( Empty_Entry,Empty_Exit ),Empty) | |
48 | ||
49 | // we just declare a state type but do not create any instance as we want to inherit from this type | |
50 | BOOST_MSM_EUML_DECLARE_STATE((Open_Entry,Open_Exit),Open_def) | |
51 | // derive to be able to add an internal transition table | |
52 | struct Open_impl : public Open_def | |
53 | { | |
54 | BOOST_MSM_EUML_DECLARE_INTERNAL_TRANSITION_TABLE(( | |
55 | open_close [internal_guard1] / internal_action1 , | |
56 | open_close [internal_guard2] / internal_action2 , | |
57 | internal_event / internal_action | |
58 | )) | |
59 | }; | |
60 | // declare an instance for the stt as we are manually declaring a state | |
61 | Open_impl const Open; | |
62 | BOOST_MSM_EUML_STATE(( Stopped_Entry,Stopped_Exit ),Stopped) | |
63 | ||
64 | // Playing is a state machine itself. | |
65 | // It has 3 substates | |
66 | BOOST_MSM_EUML_STATE(( Song1_Entry,Song1_Exit ),Song1) | |
67 | BOOST_MSM_EUML_STATE(( Song2_Entry,Song2_Exit ),Song2) | |
68 | BOOST_MSM_EUML_STATE(( Song3_Entry,Song3_Exit ),Song3) | |
69 | ||
70 | // Playing has a transition table | |
71 | BOOST_MSM_EUML_TRANSITION_TABLE(( | |
72 | // +------------------------------------------------------------------------------+ | |
73 | Song2 == Song1 + next_song / start_next_song, | |
74 | Song1 == Song2 + previous_song / start_prev_song, | |
75 | Song3 == Song2 + next_song / start_next_song, | |
76 | Song2 == Song3 + previous_song / start_prev_song | |
77 | // +------------------------------------------------------------------------------+ | |
78 | ),playing_transition_table ) | |
79 | ||
80 | BOOST_MSM_EUML_DECLARE_STATE_MACHINE( (playing_transition_table, //STT | |
81 | init_ << Song1 // Init State | |
82 | ),Playing_def) | |
83 | ||
84 | // some action for the internal transition | |
85 | BOOST_MSM_EUML_ACTION(playing_internal_action) | |
86 | { | |
87 | template <class FSM,class EVT,class SourceState,class TargetState> | |
88 | void operator()(EVT const&, FSM& ,SourceState& ,TargetState& ) | |
89 | { | |
90 | cout << "Playing::internal action" << endl; | |
91 | } | |
92 | }; | |
93 | // derive to be able to add an internal transition table | |
94 | struct Playing_ : public Playing_def | |
95 | { | |
96 | BOOST_MSM_EUML_DECLARE_INTERNAL_TRANSITION_TABLE(( | |
97 | internal_event / playing_internal_action | |
98 | )) | |
99 | }; | |
100 | // choice of back-end | |
101 | typedef msm::back::state_machine<Playing_> Playing_type; | |
102 | Playing_type const Playing; | |
103 | ||
104 | ||
105 | // state not needing any entry or exit | |
106 | BOOST_MSM_EUML_STATE((),Paused) | |
107 | ||
108 | // guard conditions | |
109 | BOOST_MSM_EUML_ACTION(good_disk_format) | |
110 | { | |
111 | template <class FSM,class EVT,class SourceState,class TargetState> | |
112 | bool operator()(EVT const& evt,FSM&,SourceState& ,TargetState& ) | |
113 | { | |
114 | // to test a guard condition, let's say we understand only CDs, not DVD | |
115 | if (evt.get_attribute(cd_type)!=DISK_CD) | |
116 | { | |
117 | std::cout << "wrong disk, sorry" << std::endl; | |
118 | // just for logging, does not block any transition | |
119 | return true; | |
120 | } | |
121 | std::cout << "good disk" << std::endl; | |
122 | return true; | |
123 | } | |
124 | }; | |
125 | // replaces the old transition table | |
126 | BOOST_MSM_EUML_TRANSITION_TABLE(( | |
127 | Stopped + play / start_playback == Playing , | |
128 | Stopped + open_close / open_drawer == Open , | |
129 | Stopped + stop == Stopped , | |
130 | // +------------------------------------------------------------------------------+ | |
131 | Open + open_close / close_drawer == Empty , | |
132 | // +------------------------------------------------------------------------------+ | |
133 | Empty + open_close / open_drawer == Open , | |
134 | Empty + cd_detected | |
135 | [good_disk_format&&(event_(cd_type)==Int_<DISK_CD>())] | |
136 | / (store_cd_info,process_(play)) | |
137 | == Stopped , | |
138 | // +------------------------------------------------------------------------------+ | |
139 | Playing + stop / stop_playback == Stopped , | |
140 | Playing + pause / pause_playback == Paused , | |
141 | Playing + open_close / stop_and_open == Open , | |
142 | // +------------------------------------------------------------------------------+ | |
143 | Paused + end_pause / resume_playback == Playing , | |
144 | Paused + stop / stop_playback == Stopped , | |
145 | Paused + open_close / stop_and_open == Open | |
146 | // +------------------------------------------------------------------------------+ | |
147 | ),transition_table) | |
148 | ||
149 | ||
150 | ||
151 | // create a state machine "on the fly" | |
152 | BOOST_MSM_EUML_DECLARE_STATE_MACHINE(( transition_table, //STT | |
153 | init_ << Empty, // Init State | |
154 | no_action, // Entry | |
155 | no_action, // Exit | |
156 | attributes_ << no_attributes_, // Attributes | |
157 | configure_ << no_configure_, // configuration | |
158 | Log_No_Transition // no_transition handler | |
159 | ), | |
160 | player_) //fsm name | |
161 | ||
162 | // choice of back-end | |
163 | typedef msm::back::state_machine<player_> player; | |
164 | ||
165 | // | |
166 | // Testing utilities. | |
167 | // | |
168 | static char const* const state_names[] = { "Stopped", "Open", "Empty", "Playing", "Paused" }; | |
169 | void pstate(player const& p) | |
170 | { | |
171 | std::cout << " -> " << state_names[p.current_state()[0]] << std::endl; | |
172 | } | |
173 | ||
174 | void test() | |
175 | { | |
176 | player p; | |
177 | // needed to start the highest-level SM. This will call on_entry and mark the start of the SM | |
178 | p.start(); | |
179 | // go to Open, call on_exit on Empty, then action, then on_entry on Open | |
180 | p.process_event(open_close); pstate(p); | |
181 | std::cout << "sending internal event (not rejected)" << std::endl; | |
182 | p.process_event(internal_event); | |
183 | std::cout << "sending open_close event. Conflict with internal transitions (rejecting event)" << std::endl; | |
184 | p.process_event(open_close); pstate(p); | |
185 | // will be rejected, wrong disk type | |
186 | p.process_event( | |
187 | cd_detected("louie, louie",DISK_DVD)); pstate(p); | |
188 | p.process_event( | |
189 | cd_detected("louie, louie",DISK_CD)); pstate(p); | |
190 | // no need to call play as the previous event does it in its action method | |
191 | //p.process_event(play); | |
192 | // at this point, Play is active | |
193 | // make transition happen inside it. Player has no idea about this event but it's ok. | |
194 | p.process_event(next_song);pstate(p); //2nd song active | |
195 | p.process_event(next_song);pstate(p);//3rd song active | |
196 | p.process_event(previous_song);pstate(p);//2nd song active | |
197 | // event handled internally in Playing, without region checking | |
198 | std::cout << "sending internal event (not rejected)" << std::endl; | |
199 | p.process_event(internal_event); | |
200 | ||
201 | p.process_event(pause); pstate(p); | |
202 | // go back to Playing | |
203 | p.process_event(end_pause); pstate(p); | |
204 | p.process_event(pause); pstate(p); | |
205 | p.process_event(stop); pstate(p); | |
206 | // event leading to the same state | |
207 | // no action method called as none is defined in the transition table | |
208 | p.process_event(stop); pstate(p); | |
209 | // test call to no_transition | |
210 | p.process_event(pause); pstate(p); | |
211 | } | |
212 | } | |
213 | ||
214 | int main() | |
215 | { | |
216 | test(); | |
217 | return 0; | |
218 | } |