UCOSII消息队列

深藏阁楼爱情的钟 2022-06-02 01:54 211阅读 0赞

**主结构体**

typedef struct os_q {              /* QUEUE CONTROL BLOCK */
        struct os_q   *OSQPtr;         /* Link to next queue control block in list of free blocks */
        void         **OSQStart;       /* Ptr to start of queue data */
        void         **OSQEnd;         /* Ptr to end of queue data */
        void         **OSQIn;          /* Ptr to where next message will be inserted in the Q */
        void         **OSQOut;         /* Ptr to where next message will be extracted from the Q */
        INT16U         OSQSize;        /* Size of queue (maximum number of entries) */
        INT16U         OSQEntries;     /* Current number of entries in the queue */
    } OS_Q;
    
    typedef struct os_q_data {
        void          *OSMsg;          /* Pointer to next message to be extracted from queue */
        INT16U         OSNMsgs;        /* Number of messages in message queue */
        INT16U         OSQSize;        /* Size of message queue */
        OS_PRIO        OSEventTbl[OS_EVENT_TBL_SIZE];  /* List of tasks waiting for event to occur */
        OS_PRIO        OSEventGrp;     /* Group corresponding to tasks waiting for event to occur */
    } OS_Q_DATA;
    
    typedef struct os_event {
        INT8U    OSEventType;          /* Type of event control block (see OS_EVENT_TYPE_xxxx) */
        void    *OSEventPtr;           /* Pointer to message or queue structure */
        INT16U   OSEventCnt;           /* Semaphore Count (not used if other EVENT type) */
        OS_PRIO  OSEventGrp;           /* Group corresponding to tasks waiting for event to occur */
        OS_PRIO  OSEventTbl[OS_EVENT_TBL_SIZE]; /* List of tasks waiting for event to occur */
    
    #if OS_EVENT_NAME_EN > 0u
        INT8U   *OSEventName;
    #endif
    } OS_EVENT;

**API函数**

//无等待地从消息队列中得到一个消息
    void *OSQAccept (OS_EVENT *pevent,
                     INT8U *perr);
    
    //创建
    OS_EVENT *OSQCreate (void **start,
                         INT16U size);
    
    //删除
    OS_EVENT *OSQDel (OS_EVENT *pevent,
                      INT8U opt,
                      INT8U *perr);
    
    //清空
    INT8U OSQFlush (OS_EVENT *pevent);
    
    //等待-1，接收消息
    void *OSQPend (OS_EVENT *pevent,
                   INT32U timeout,
                   INT8U *perr);
    
    //取消等待
    INT8U OSQPendAbort (OS_EVENT *pevent,
                        INT8U opt,
                        INT8U *perr);
    
    //释放+1，发送消息（队列式）
    INT8U OSQPost (OS_EVENT *pevent,
                   void *pmsg);
    
    //发送消息（堆栈式）
    INT8U OSQPostFront (OS_EVENT *pevent,
                        void *pmsg);
    
    //单选项的消息发送
    INT8U OSQPostOpt (OS_EVENT *pevent,
                      void *pmsg,
                      INT8U opt);
    
    //查询
    INT8U OSQQuery (OS_EVENT *pevent,
                    OS_Q_DATA *p_q_data);

**应用举例**

#define OSQ_MSG_NUM 1 //消息队列消息数量
    OS_EVENT *DATA_Msg;
    void *MsgGrp[OSQ_MSG_NUM];
    
    void start_task(void *pdata)
    {
        OS_CRITICAL_ENTER();    //进入临界区
    
        DATA_Msg = OSQCreate ((void**   )&MsgGrp[0],    
                             (INT16U )OSQ_MSG_NUM);
    
        OS_EXIT_CRITICAL();
    }
    
    void msgpost_task(void *p_arg)
    {
        static u8 msg_num;
        OS_Q_DATA p_q_data;
    
        OSQQuery(DATA_Msg, &p_q_data);
        if(p_q_data.OSNMsgs >= OSQ_MSG_NUM)
        {
            printf("OSQQuery OSNMsgs: %d\r\n", p_q_data.OSNMsgs);
            return;
        }
    
        msg_num++;
        OSQPost((OS_EVENT*  )DATA_Msg,      
                (void*      )&msg_num);
    }
    
    void msgpend_task(void *p_arg)
    {
        void *p;
        INT8U err;
        u8 msg_num;
    
        p = OSQPend((OS_EVENT*  )DATA_Msg,   
                    (INT32U     )0,
                    (INT8U*     )&err);
    
        msg_num = *p;
    }