一、状态机实现

1. 事件入栈

uint8_t Fsm_EventPost(FSM_st *p_Fsm，uint8_t Event)
{if(NULL == p_Fsm){return FALSE;}p_Fsm->EventQueue[p_Fsm->EventWrite] = Event;p_Fsm->EventWrite = (p_Fsm->EventWrite+1)% FSM_MAX_EVENT;return TRUE;
}

2. 事件出栈，一般在事件执行时调用

static uchar Fsm_EventGet(FSM_st *p_Fsm)
{uint8_t RetEvent = FSM_EVENT_NONE;if(NULL == p_Fsm){return FSM_EVENT_NONE;}if(p_Fsm->EventRead == p_Fsm->EventWrite){return FSM_EVENT_NONE;	}else{RetEvent = p_Fsm->EventQueue[p_Fsm->EventRead];p_Fsm->EventRead++;p_Fsm->EventRead %= FSM_MAX_EVENT;return u8_RetEvent;}
}

3. 事件执行

void Fsm_Execute(FSM_st *p_Fsm, const state_handle_st *ptbl)
{uint8_t Ret =FSM_RET_IGNORED;uint8_t Event = FSM_EVENT_NONE；if ((NULL == p_Fsm) || ( NULL == ptbl)){return;}Event = Fsm_EventGet(p_Fsm);if(NULL != p_Fsm->p_GlobalHandle）{Ret = p_Fsm->p_GlobalHandle(Event);if(FSM_RET_TRAN == Ret){ptbl[p_Fsm->CurState].p_Handle(FSM_EVENT_EXIT);ptbl[p_Fsm->u8_NextState].p_Handle(FSM_EVENT_ENTER);p_Fsm->CurState = p_Fsm->NextState;return;}else if (FSM_RET_IGNORED != Ret){return;}}Ret = ptbl[p_Fsm->CurState].p_Handle(Event);if(FSM_RET_TRAN == Ret){ptbl[p_Fsm->CurState].p_Handle(FSM_EVENT_EXIT);ptbl[p_Fsm->u8_NextState].p_Handle(FSM_EVENT_ENTER);p_Fsm->CurState = p_Fsm->NextState;return;}}

4. 状态切换

uint8_t Fsm_StateTrans(FSM_st *p_Fsm, uint8_t State)
{if(NULL == p_Fsm){return FSM_EVENT_NONE;}p_Fsm->NextState = State;return (FSM_RET_TRAN);}

二、状态机应用-实例化状态机

举例： 针对闹钟功能

1. 列出所有状态

typedef enum
{STATE_SETTING, //闹钟时间设置STATE_TICK     //倒计时中}State_type;

2. 列出所有事件

typedef enum
{//进入和退出 一般是执行完当前状态的事件后进入下一个状态时调用EVENT_ENTER, EVENT_EXIT,EVENT_UP,  //按键加 计时加一小时EVENT_DOWN, //按键减 计时减一小时EVENT_ENTER	//确认键
}Event_type;

3. 定义状态列表

typedef struct 
{uint8_t  State;    //状态uint8_t  (*p_Handle)(uint8_t  Event); //状态执行函数 参数是事件
}state_handle_st;

const state_handle_st Func_tbl[2] =
{{STATE_SETTING,      		Setting_Handle},{STATE_TICK   ,       	    Tick_Handle},
};

static uint8_t Setting_Handle(uint8_t Event)
{switch}static uint8_t Tick_Handle(uint8_t Event)
{}

4. 实例化状态机并初始化

5. 各状态对应事件处理的实现（包含状态进入，退出，事件队列处理）