geek青年的状态机，查表，纯C语言实现

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enum message { play, stop, forward, backward, record, pause };

状态迁移表与状态迁移图完全等价。

1 struct transition fsm[transition_num] = {
2         /* current_state, message/event, next_state*/
3     {s_play,	stop,		s_stop},
4     {s_play,	pause,		s_pause},
5     {s_pause,	pause,		s_play},
6     {s_pause,	stop,		s_stop},
7     {s_stop,	forward,	s_forward},
8     {s_stop,	play,		s_play},
9     {s_stop,	backward,	s_backward},
10     {s_stop,	record,		s_record},
11     {s_forward,	stop,		s_stop},
12     {s_backward,	stop,		s_stop},
13     {s_record,	stop,		s_stop} };

1 enum state { s_stop=‘s‘, s_play=‘p‘, s_forward=‘f‘, s_backward=‘b‘, s_pause=‘_‘, s_record=‘r‘  };
2 enum message { play, stop, forward, backward, record, pause };
3 
4 struct transition {
5     enum state current;
6     enum message m;
7     enum state next;
8 };

1 #define transition_num  11

1 struct state_action state_action_map[state_num] = {
2     {s_stop, do_stop},
3     {s_play, do_play},
4     {s_forward, do_forward},
5     {s_backward, do_backward},
6     {s_pause, do_pause},
7     {s_record, do_record}};

1 #define state_num 6
2 typedef void (*action_foo)() ;
3 
4 enum state { s_stop=‘s‘, s_play=‘p‘, s_forward=‘f‘, s_backward=‘b‘, s_pause=‘_‘, s_record=‘r‘  };
5 
6 /* action starts */
7 void do_stop() {printf ("I am in state stop and should doing something here.\n");}
8 void do_play() {printf ("I am in state play and should doing something here.\n");}
9 void do_forward() {printf ("I am in state forward and should doing something here.\n");}
10 void do_backward() {printf ("I am in state backward and should doing something here.\n");}
11 void do_pause() {printf ("I am in state pause and should doing something here.\n");}
12 void do_record() {printf ("I am in state record and should doing something here.\n");}
13 
14 struct state_action {
15     enum state m_state;
16     action_foo foo;
17 };

1 void state_change(enum message m)
2 {
3     static state = s_stop;
4     enum state next;
5     int index = 0;
6 
7     index = lookup_transition(state, m, fsm);
8     if(index!=ERR)
9     {
10         state = fsm[index].next;
11         lookup_action(state, state_action_map)();
12     }
13     return;
14 }

1 int const ERR = -1;
2 int lookup_transition (enum state s, enum message m, struct transition * t)
3 {
4     int ret=ERR;
5     int i;
6     for(i=0;i<transition_num;++i)
7     {
8         if(t[i].current == s && t[i].m == m)
9         {
10             ret = i;
11         }
12     }
13     return ret;
14 }
15 
16 action_foo ACTION_NOT_FOUND = NULL;
17 action_foo lookup_action(enum state s, struct state_action* a)
18 {
19     action_foo ret = ACTION_NOT_FOUND;
20     int i=0;
21     for (i=0;i<state_num;++i)
22     {
23         if(s == a[i].m_state)
24         {
25             ret = a[i].foo;
26         }
27     }
28     return ret;
29 }

这一篇和上一篇的代码在这里[http://download.csdn.net/detail/younggift/7569627]。

geek青年的状态机，查表，纯C语言实现,布布扣,bubuko.com

geek青年的状态机，查表，纯C语言实现

标签：style   blog   http   使用   width   文件   

原文地址：http://blog.csdn.net/younggift/article/details/35848677