os_q.c

uCOS-II学习资料

    if (pevent == (OS_EVENT *)0) {                     /* Validate 'pevent'                            */
        return (OS_ERR_PEVENT_NULL);
    }
#endif
    if (pevent->OSEventType != OS_EVENT_TYPE_Q) {      /* Validate event block type                    */
        return (OS_ERR_EVENT_TYPE);
    }
    OS_ENTER_CRITICAL();
    if (pevent->OSEventGrp != 0) {                     /* See if any task pending on queue             */
                                                       /* Ready highest priority task waiting on event */
        (void)OS_EventTaskRdy(pevent, pmsg, OS_STAT_Q, OS_STAT_PEND_OK);
        OS_EXIT_CRITICAL();
        OS_Sched();                                    /* Find highest priority task ready to run      */
        return (OS_ERR_NONE);
    }
    pq = (OS_Q *)pevent->OSEventPtr;                   /* Point to queue control block                 */
    if (pq->OSQEntries >= pq->OSQSize) {               /* Make sure queue is not full                  */
        OS_EXIT_CRITICAL();
        return (OS_ERR_Q_FULL);
    }
    *pq->OSQIn++ = pmsg;                               /* Insert message into queue                    */
    pq->OSQEntries++;                                  /* Update the nbr of entries in the queue       */
    if (pq->OSQIn == pq->OSQEnd) {                     /* Wrap IN ptr if we are at end of queue        */
        pq->OSQIn = pq->OSQStart;
    }
    OS_EXIT_CRITICAL();
    return (OS_ERR_NONE);
}
#endif
/*$PAGE*/
/*
*********************************************************************************************************
*                                   POST MESSAGE TO THE FRONT OF A QUEUE
*
* Description: This function sends a message to a queue but unlike OSQPost(), the message is posted at
*              the front instead of the end of the queue.  Using OSQPostFront() allows you to send
*              'priority' messages.
*
* Arguments  : pevent        is a pointer to the event control block associated with the desired queue
*
*              pmsg          is a pointer to the message to send.
*
* Returns    : OS_ERR_NONE           The call was successful and the message was sent
*              OS_ERR_Q_FULL         If the queue cannot accept any more messages because it is full.
*              OS_ERR_EVENT_TYPE     If you didn't pass a pointer to a queue.
*              OS_ERR_PEVENT_NULL    If 'pevent' is a NULL pointer
*
* Note(s)    : As of V2.60, this function allows you to send NULL pointer messages.
*********************************************************************************************************
*/

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



#if OS_ARG_CHK_EN > 0
    if (pevent == (OS_EVENT *)0) {                    /* Validate 'pevent'                             */
        return (OS_ERR_PEVENT_NULL);
    }
#endif
    if (pevent->OSEventType != OS_EVENT_TYPE_Q) {     /* Validate event block type                     */
        return (OS_ERR_EVENT_TYPE);
    }
    OS_ENTER_CRITICAL();
    if (pevent->OSEventGrp != 0) {                    /* See if any task pending on queue              */
                                                      /* Ready highest priority task waiting on event  */
        (void)OS_EventTaskRdy(pevent, pmsg, OS_STAT_Q, OS_STAT_PEND_OK);
        OS_EXIT_CRITICAL();
        OS_Sched();                                   /* Find highest priority task ready to run       */
        return (OS_ERR_NONE);
    }
    pq = (OS_Q *)pevent->OSEventPtr;                  /* Point to queue control block                  */
    if (pq->OSQEntries >= pq->OSQSize) {              /* Make sure queue is not full                   */
        OS_EXIT_CRITICAL();
        return (OS_ERR_Q_FULL);
    }
    if (pq->OSQOut == pq->OSQStart) {                 /* Wrap OUT ptr if we are at the 1st queue entry */
        pq->OSQOut = pq->OSQEnd;
    }
    pq->OSQOut--;
    *pq->OSQOut = pmsg;                               /* Insert message into queue                     */
    pq->OSQEntries++;                                 /* Update the nbr of entries in the queue        */
    OS_EXIT_CRITICAL();
    return (OS_ERR_NONE);
}
#endif
/*$PAGE*/
/*
*********************************************************************************************************
*                                        POST MESSAGE TO A QUEUE
*
* Description: This function sends a message to a queue.  This call has been added to reduce code size
*              since it can replace both OSQPost() and OSQPostFront().  Also, this function adds the
*              capability to broadcast a message to ALL tasks waiting on the message queue.
*
* Arguments  : pevent        is a pointer to the event control block associated with the desired queue
*
*              pmsg          is a pointer to the message to send.
*
*              opt           determines the type of POST performed:
*                            OS_POST_OPT_NONE         POST to a single waiting task
*                                                     (Identical to OSQPost())
*                            OS_POST_OPT_BROADCAST    POST to ALL tasks that are waiting on the queue
*                            OS_POST_OPT_FRONT        POST as LIFO (Simulates OSQPostFront())
*                            OS_POST_OPT_NO_SCHED     Indicates that the scheduler will NOT be invoked
*
* Returns    : OS_ERR_NONE           The call was successful and the message was sent
*              OS_ERR_Q_FULL         If the queue cannot accept any more messages because it is full.
*              OS_ERR_EVENT_TYPE     If you didn't pass a pointer to a queue.
*              OS_ERR_PEVENT_NULL    If 'pevent' is a NULL pointer
*
* Warning    : Interrupts can be disabled for a long time if you do a 'broadcast'.  In fact, the
*              interrupt disable time is proportional to the number of tasks waiting on the queue.
*********************************************************************************************************
*/

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



#if OS_ARG_CHK_EN > 0
    if (pevent == (OS_EVENT *)0) {                    /* Validate 'pevent'                             */
        return (OS_ERR_PEVENT_NULL);
    }
#endif
    if (pevent->OSEventType != OS_EVENT_TYPE_Q) {     /* Validate event block type                     */
        return (OS_ERR_EVENT_TYPE);
    }
    OS_ENTER_CRITICAL();
    if (pevent->OSEventGrp != 0x00) {                 /* See if any task pending on queue              */
        if ((opt & OS_POST_OPT_BROADCAST) != 0x00) {  /* Do we need to post msg to ALL waiting tasks ? */
            while (pevent->OSEventGrp != 0) {         /* Yes, Post to ALL tasks waiting on queue       */
                (void)OS_EventTaskRdy(pevent, pmsg, OS_STAT_Q, OS_STAT_PEND_OK);
            }
        } else {                                      /* No,  Post to HPT waiting on queue             */
            (void)OS_EventTaskRdy(pevent, pmsg, OS_STAT_Q, OS_STAT_PEND_OK);
        }
        OS_EXIT_CRITICAL();
        if ((opt & OS_POST_OPT_NO_SCHED) == 0) {	  /* See if scheduler needs to be invoked          */
            OS_Sched();                               /* Find highest priority task ready to run       */
        }
        return (OS_ERR_NONE);
    }
    pq = (OS_Q *)pevent->OSEventPtr;                  /* Point to queue control block                  */
    if (pq->OSQEntries >= pq->OSQSize) {              /* Make sure queue is not full                   */
        OS_EXIT_CRITICAL();
        return (OS_ERR_Q_FULL);
    }
    if ((opt & OS_POST_OPT_FRONT) != 0x00) {          /* Do we post to the FRONT of the queue?         */
        if (pq->OSQOut == pq->OSQStart) {             /* Yes, Post as LIFO, Wrap OUT pointer if we ... */
            pq->OSQOut = pq->OSQEnd;                  /*      ... are at the 1st queue entry           */
        }
        pq->OSQOut--;
        *pq->OSQOut = pmsg;                           /*      Insert message into queue                */
    } else {                                          /* No,  Post as FIFO                             */
        *pq->OSQIn++ = pmsg;                          /*      Insert message into queue                */
        if (pq->OSQIn == pq->OSQEnd) {                /*      Wrap IN ptr if we are at end of queue    */
            pq->OSQIn = pq->OSQStart;
        }
    }
    pq->OSQEntries++;                                 /* Update the nbr of entries in the queue        */
    OS_EXIT_CRITICAL();
    return (OS_ERR_NONE);
}
#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
*
*              p_q_data      is a pointer to a structure that will contain information about the message
*                            queue.
*
* Returns    : OS_ERR_NONE         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
*              OS_ERR_PDATA_NULL   If 'p_q_data' is a NULL pointer
*********************************************************************************************************
*/

#if OS_Q_QUERY_EN > 0
INT8U  OSQQuery (OS_EVENT *pevent, OS_Q_DATA *p_q_data)
{
    OS_Q      *pq;
    INT8U      i;
#if OS_LOWEST_PRIO <= 63
    INT8U     *psrc;
    INT8U     *pdest;
#else
    INT16U    *psrc;
    INT16U    *pdest;
#endif
#if OS_CRITICAL_METHOD == 3                            /* Allocate storage for CPU status register     */
    OS_CPU_SR  cpu_sr = 0;
#endif



#if OS_ARG_CHK_EN > 0
    if (pevent == (OS_EVENT *)0) {                     /* Validate 'pevent'                            */
        return (OS_ERR_PEVENT_NULL);
    }
    if (p_q_data == (OS_Q_DATA *)0) {                  /* Validate 'p_q_data'                          */
        return (OS_ERR_PDATA_NULL);
    }
#endif
    if (pevent->OSEventType != OS_EVENT_TYPE_Q) {      /* Validate event block type                    */
        return (OS_ERR_EVENT_TYPE);
    }
    OS_ENTER_CRITICAL();
    p_q_data->OSEventGrp = pevent->OSEventGrp;         /* Copy message queue wait list                 */
    psrc                 = &pevent->OSEventTbl[0];
    pdest                = &p_q_data->OSEventTbl[0];
    for (i = 0; i < OS_EVENT_TBL_SIZE; i++) {
        *pdest++ = *psrc++;
    }
    pq = (OS_Q *)pevent->OSEventPtr;
    if (pq->OSQEntries > 0) {
        p_q_data->OSMsg = *pq->OSQOut;                 /* Get next message to return if available      */
    } else {
        p_q_data->OSMsg = (void *)0;
    }
    p_q_data->OSNMsgs = pq->OSQEntries;
    p_q_data->OSQSize = pq->OSQSize;
    OS_EXIT_CRITICAL();
    return (OS_ERR_NONE);
}
#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.
*********************************************************************************************************
*/

void  OS_QInit (void)
{
#if OS_MAX_QS == 1
    OSQFreeList         = &OSQTbl[0];                /* Only ONE queue!                                */
    OSQFreeList->OSQPtr = (OS_Q *)0;
#endif

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



    OS_MemClr((INT8U *)&OSQTbl[0], sizeof(OSQTbl));  /* Clear the queue table                          */
    pq1 = &OSQTbl[0];
    pq2 = &OSQTbl[1];
    for (i = 0; i < (OS_MAX_QS - 1); i++) {          /* Init. list of free QUEUE control blocks        */
        pq1->OSQPtr = pq2;
        pq1++;
        pq2++;
    }
    pq1->OSQPtr = (OS_Q *)0;
    OSQFreeList = &OSQTbl[0];
#endif
}
#endif                                               /* OS_Q_EN                                        */