一个状态机简单的例子

时间：2010-05-02 来源：mingbo213

有关状态机可以参考： http://blog.csdn.net/hillgong/archive/2009/09/16/4557496.aspx 用状态机原理进行软件设计.pdf Practical.Statecharts.in.CCQuantum.Programming.for.Embedded.Systems.pdf Practical UML Statecharts in C/C++, Second Edition: Event-Driven Programming for Embedded Systems Modeling Software with Finite State Machines: A Practical Approach /*
* (网络搜索有关状态机的东西，找到一个题目，简单做一下)
* 假设地铁的门有2个状态，开和关。
* 在关的情况下，投入一个硬币，门就开了；
* 在关的状态下，强行进入，就发出警告。 * 在开的情况下，人一进入，门就关了；
* 在开的情况下，继续投币，就说：“thank you”。
* 要求用C代码写出状态机，并写出main函数，完全写出代码实现这个状态机。 *
*/ #include <stdio.h> typedef enum
{
    STATION_CLOSE,
    STATION_OPEN,
}StationState; struct station_door
{
    unsigned int doorstate;
}; struct station_door g_door; void station_init(void)
{
    g_door.doorstate = STATION_CLOSE;
} /*投币处理函数*/
unsigned int EventHandlerOfPutCoin()
{
    switch(g_door.doorstate)
    {
        case STATION_CLOSE:
            g_door.doorstate = STATION_OPEN;
            printf("the door is open\n");
            break;
        case STATION_OPEN:
            printf("thank you\n");
            break;
        default :
            break;
    }     return 0;
} /*进入处理函数*/
unsigned int EventHandlerOfGetIn()
{
    switch(g_door.doorstate)
    {
        case STATION_CLOSE:
            printf("alerting\n");
            break;
        case STATION_OPEN:
            g_door.doorstate = STATION_CLOSE;
            printf("the door is close\n");
            break;
        default :
            break;
    }     return 0;
} void get_event(int *event)
{
    if(NULL == event)
        return;     if(g_door.doorstate == STATION_CLOSE)
    {
        printf("Current door state is CLOSE\n");
    }
    else
    {
        printf("Current door state is OPEN\n");
    }     printf("Please select event\n");
    printf("1:put coin\n");
    printf("2:get in\n");
    scanf("%d",event);
} void event_handler(int event)
{
    if(event == 1)
    {
        EventHandlerOfPutCoin();
    }
    else if(event == 2)
    {
        EventHandlerOfGetIn();
    }
    else
    {
        return;
    }
} int main(void)
{
    int event;     station_init();     while(1)
    {
        get_event(&event);
        event_handler(event);
    }     return 0;
}

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