os_q.c

avr ucos 代码 测试环境：source insight WINAVR 4个进程

*                                 1) OS_POST_OPT_NONE
*                                    相当于 OSQPost()
*
*                                 2) OS_POST_OPT_FRONT
*                                    相当于 OSQPostFront()
*
*                                 3) OS_POST_OPT_BROADCAST
*                                    相当于 OSQPost() 但可以以广播方式发送 to ALL waiting tasks
*
*                                 4) OS_POST_OPT_FRONT + OS_POST_OPT_BROADCAST  相当于
*                                    OSQPostFront() 可以以广播方式发送
*********************************************************************************************************
*/

#if OS_Q_POST_OPT_EN > 0
INT8U  OSQPostOpt (OS_EVENT *pevent, void *msg, INT8U opt)
{
#if OS_CRITICAL_METHOD == 3                      /* Allocate storage for CPU status register           */
    OS_CPU_SR  cpu_sr;
#endif
    OS_Q      *pq;


#if OS_ARG_CHK_EN > 0
    if (pevent == (OS_EVENT *)0) {                    /* Validate 'pevent'                             */
        return (OS_ERR_PEVENT_NULL);
    }//非法pevent 
    if (msg == (void *)0) {                           /* Make sure we are not posting a NULL pointer   */
        return (OS_ERR_POST_NULL_PTR);
    }//保证没有送空指针
    if (pevent->OSEventType != OS_EVENT_TYPE_Q) {     /* Validate event block type                     */
        return (OS_ERR_EVENT_TYPE);
    }//不是事件块类型
#endif
    OS_ENTER_CRITICAL();
    if (pevent->OSEventGrp != 0x00) {                 /* See if any task pending on queue              */
		//如果有任务在队列中挂起
        if ((opt & OS_POST_OPT_BROADCAST) != 0x00) {  /* Do we need to post msg to ALL waiting tasks ? */
			//向所有任务发送？
            while (pevent->OSEventGrp != 0x00) {      /* Yes, Post to ALL tasks waiting on queue       */
                OS_EventTaskRdy(pevent, msg, OS_STAT_Q);
            }//是的。如果将opt参数中的OS_POST_OPT_BROADCAST位置为1，则所有正在等待消息
            //的任务都能接收到这则消息，并且被OS_EventTaskRdy从等待列表中删除。
        } else {//不要向所有的等待任务发消息
            OS_EventTaskRdy(pevent, msg, OS_STAT_Q);  /* No,  Post to HPT waiting on queue             */
			//那就只发优先级最高的。
        }
        OS_EXIT_CRITICAL();
        OS_Sched();                                   /* Find highest priority task ready to run       */
		//要任务调度
        return (OS_NO_ERR);
    }
    pq = (OS_Q *)pevent->OSEventPtr;                  /* Point to queue control block                  */
	//指向队列控制块
    if (pq->OSQEntries >= pq->OSQSize) {              /* Make sure queue is not full                   */
        OS_EXIT_CRITICAL();//如果满了，返回错误代码
        return (OS_Q_FULL);
    }
    if ((opt & OS_POST_OPT_FRONT) != 0x00) {          /* Do we post to the FRONT of the queue?         */
		//FIFO还是LIFO，如果是LIFO
        if (pq->OSQOut == pq->OSQStart) {             /* Yes, Post as LIFO, Wrap OUT pointer if we ... */
            pq->OSQOut = pq->OSQEnd;                  /*      ... are at the 1st queue entry           */
        }//如果是后进先出，则相当于OSQPostFront 。如果我人在队列第一个，则调整
        pq->OSQOut--;
        *pq->OSQOut = msg;                            /*      Insert message into queue                */
		//插入消息
    } else {                                          /* No,  Post as FIFO                             */
    //如果是FIFO
        *pq->OSQIn++ = msg;                           /*      Insert message into queue                */
        if (pq->OSQIn == pq->OSQEnd) {                /*      Wrap IN ptr if we are at end of queue    */
            pq->OSQIn = pq->OSQStart;//如果在最末尾，则调整
        }
    }
    pq->OSQEntries++;                                 /* Update the nbr of entries in the queue        */
	//更新消息条数
    OS_EXIT_CRITICAL();
    return (OS_NO_ERR);
}
#endif
/*$PAGE*/
/*
*********************************************************************************************************
*                                        QUERY A MESSAGE QUEUE
*
* Description: This function obtains information about a message queue.
*
* Arguments  : pevent        is a pointer to the event control block associated with the desired queue
*
*              pdata         is a pointer to a structure that will contain information about the message
*                            queue.
*
* Returns    : OS_NO_ERR           The call was successful and the message was sent
*              OS_ERR_EVENT_TYPE   If you are attempting to obtain data from a non queue.
*              OS_ERR_PEVENT_NULL  If 'pevent' is a NULL pointer
                                       获取消息队列状态
描述：获取消息队列的信息
参数：pevent：指向事件控制块结合目标队列的指针
                pdata：指向消息队列包含信息的结构指针
返回：OS_NO_ERR           调用成功，消息成功发送
*              OS_ERR_EVENT_TYPE   你想获取非队列的信息
*              OS_ERR_PEVENT_NULL  如果 'pevent' 是一个NULL指针
*********************************************************************************************************
*/

#if OS_Q_QUERY_EN > 0
INT8U  OSQQuery (OS_EVENT *pevent, OS_Q_DATA *pdata)
{
#if OS_CRITICAL_METHOD == 3                      /* Allocate storage for CPU status register           */
    OS_CPU_SR  cpu_sr;
#endif
    OS_Q      *pq;
    INT8U     *psrc;
    INT8U     *pdest;


#if OS_ARG_CHK_EN > 0
    if (pevent == (OS_EVENT *)0) {                         /* Validate 'pevent'     */
        return (OS_ERR_PEVENT_NULL);
    }//非法pevent 
    if (pevent->OSEventType != OS_EVENT_TYPE_Q) {          /* Validate event block type   */
        return (OS_ERR_EVENT_TYPE);
    }//保证没有送空指针
#endif
    OS_ENTER_CRITICAL();
//复制等待任务列表
    pdata->OSEventGrp = pevent->OSEventGrp;           /* Copy message queue wait list  */
    psrc              = &pevent->OSEventTbl[0];
    pdest             = &pdata->OSEventTbl[0];
#if OS_EVENT_TBL_SIZE > 0//从0开始，慢慢复制吧。
    *pdest++          = *psrc++;
#endif

#if OS_EVENT_TBL_SIZE > 1
    *pdest++          = *psrc++;
#endif

#if OS_EVENT_TBL_SIZE > 2
    *pdest++          = *psrc++;
#endif

#if OS_EVENT_TBL_SIZE > 3
    *pdest++          = *psrc++;
#endif

#if OS_EVENT_TBL_SIZE > 4
    *pdest++          = *psrc++;
#endif

#if OS_EVENT_TBL_SIZE > 5
    *pdest++          = *psrc++;
#endif

#if OS_EVENT_TBL_SIZE > 6
    *pdest++          = *psrc++;
#endif

#if OS_EVENT_TBL_SIZE > 7
    *pdest            = *psrc;
#endif
    pq = (OS_Q *)pevent->OSEventPtr;
    if (pq->OSQEntries > 0) {//如果有消息等待，则提取出（并没有删除）队列中最早进入
    //队列的消息，并将其复制到OSMsg中，OSQQuery并没有改动.OSQOut的指针。
        pdata->OSMsg = *pq->OSQOut;                        /* Get next message to return if available  */
    } else {//如果没有任务等待，则返回空指针
        pdata->OSMsg = (void *)0;
    }
    pdata->OSNMsgs = pq->OSQEntries;//队列中消息数
    pdata->OSQSize = pq->OSQSize;//队列容易大小
    OS_EXIT_CRITICAL();
    return (OS_NO_ERR);
}
#endif                                                     /* OS_Q_QUERY_EN                            */

/*$PAGE*/
/*
*********************************************************************************************************
*                                      QUEUE MODULE INITIALIZATION
*
* Description : This function is called by uC/OS-II to initialize the message queue module.  Your
*               application MUST NOT call this function.
*
* Arguments   :  none
*
* Returns     : none
*
* Note(s)    : This function is INTERNAL to uC/OS-II and your application should not call it.
                                                   初始化消息队列
描述：由ucos调用初始化消息队列模型，应用程序不能调用
参数：无
返回：无
备注：由ucos调用初始化消息队列模型，应用程序不能调用
*********************************************************************************************************
*/

void  OS_QInit (void)
{
#if OS_MAX_QS == 1//如果只有一个队列
    OSQFreeList         = &OSQTbl[0];            /* Only ONE queue!     */
    OSQFreeList->OSQPtr = (OS_Q *)0;//前趋为零指针
#endif

#if OS_MAX_QS >= 2
    INT16U  i;
    OS_Q   *pq1;
    OS_Q   *pq2;


    pq1 = &OSQTbl[0];
    pq2 = &OSQTbl[1];
    for (i = 0; i < (OS_MAX_QS - 1); i++) {      /* Init. list of free QUEUE control blocks            */
		//初始化空闲队列控制块，组成一个单向链表
        pq1->OSQPtr = pq2;
        pq1++;
        pq2++;
    }
    pq1->OSQPtr = (OS_Q *)0;//后趋附指向NULL指针
    OSQFreeList = &OSQTbl[0];//空链表指针指向首地址。
#endif
}
#endif                                                     /* OS_Q_EN                                  */