if (pevent->OSEventType != OS_EVENT_TYPE_Q) {/* Validate event block type                          */        OS_EXIT_CRITICAL();        *err = OS_ERR_EVENT_TYPE;        return ((void *)0);    }    pq = (OS_Q  *)(pevent->OSEventPtr);                     /* Point at queue control block                       */    if (pq->OSQEntries != 0) {                   /* See if any messages in the queue                   */        msg = *pq->OSQOut++;                     /* Yes, extract oldest message from the queue         */        pq->OSQEntries--;                        /* Update the number of entries in the queue          */        if (pq->OSQOut == pq->OSQEnd) {          /* Wrap OUT pointer if we are at the end of the queue */            pq->OSQOut = pq->OSQStart;        }        OS_EXIT_CRITICAL();        *err = OS_NO_ERR;    } else if (OSIntNesting > 0) {               /* See if called from ISR ...                         */        OS_EXIT_CRITICAL();                      /* ... can't PEND from an ISR                         */        *err = OS_ERR_PEND_ISR;    } else {        OSTCBCur->OSTCBStat    |= OS_STAT_Q;     /* Task will have to pend for a message to be posted  */        OSTCBCur->OSTCBDly      = timeout;       /* Load timeout into TCB                              */        OSEventTaskWait(pevent);                 /* Suspend task until event or timeout occurs         */        OS_EXIT_CRITICAL();        OSSched();                               /* Find next highest priority task ready to run       */        OS_ENTER_CRITICAL();        if ((msg = OSTCBCur->OSTCBMsg) != (void *)0) {/* Did we get a message?                         */            OSTCBCur->OSTCBMsg      = (void *)0;      /* Extract message from TCB (Put there by QPost) */            OSTCBCur->OSTCBStat     = OS_STAT_RDY;            OSTCBCur->OSTCBEventPtr = (OS_EVENT *)0;  /* No longer waiting for event                   */            OS_EXIT_CRITICAL();            *err                    = OS_NO_ERR;        } else if (OSTCBCur->OSTCBStat & OS_STAT_Q) { /* Timed out if status indicates pending on Q    */            OSEventTO(pevent);            OS_EXIT_CRITICAL();            msg                     = (void *)0;      /* No message received                           */            *err                    = OS_TIMEOUT;     /* Indicate a timeout occured                    */        } else {            msg = *pq->OSQOut++;                      /* Extract message from queue                    */            pq->OSQEntries--;                         /* Update the number of entries in the queue     */            if (pq->OSQOut == pq->OSQEnd) {           /* Wrap OUT pointer if we are at the end of Q    */                pq->OSQOut = pq->OSQStart;            }            OSTCBCur->OSTCBEventPtr = (OS_EVENT *)0;            OS_EXIT_CRITICAL();            *err = OS_NO_ERR;        }    }                                                     return (msg);                                     /* Return message received (or NULL)             */}/*$PAGE*//***********************************************************************************************************                                        POST MESSAGE TO A QUEUE** Description: This function sends a message to a queue** Arguments  : pevent        is a pointer to the event control block associated with the desired queue**              msg           is a pointer to the message to send.  You MUST NOT send a NULL pointer.  ** Returns    : OS_NO_ERR          The call was successful and the message was sent*              OS_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.**********************************************************************************************************/INT8U OSQPost (OS_EVENT *pevent, void *msg){    OS_Q   *pq;    OS_ENTER_CRITICAL();    if (pevent->OSEventType != OS_EVENT_TYPE_Q) {     /* Validate event block type                     */        OS_EXIT_CRITICAL();        return (OS_ERR_EVENT_TYPE);    }    if (pevent->OSEventGrp) {                         /* See if any task pending on queue              */        OSEventTaskRdy(pevent, msg, OS_STAT_Q);       /* Ready highest priority task waiting on event  */        OS_EXIT_CRITICAL();        OSSched();                                    /* Find highest priority task ready to run       */        return (OS_NO_ERR);    } else {        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_Q_FULL);        } else {            *pq->OSQIn++ = msg;                       /* 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_NO_ERR);    }}/*$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**              msg           is a pointer to the message to send.  You MUST NOT send a NULL pointer.  ** Returns    : OS_NO_ERR          The call was successful and the message was sent*              OS_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.**********************************************************************************************************/INT8U OSQPostFront (OS_EVENT *pevent, void *msg){    OS_Q   *pq;    OS_ENTER_CRITICAL();    if (pevent->OSEventType != OS_EVENT_TYPE_Q) {     /* Validate event block type                     */        OS_EXIT_CRITICAL();        return (OS_ERR_EVENT_TYPE);    }    if (pevent->OSEventGrp) {                         /* See if any task pending on queue              */        OSEventTaskRdy(pevent, msg, OS_STAT_Q);       /* Ready highest priority task waiting on event  */        OS_EXIT_CRITICAL();        OSSched();                                    /* Find highest priority task ready to run       */        return (OS_NO_ERR);    } else {        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_Q_FULL);        } else {            if (pq->OSQOut == pq->OSQStart) {         /* Wrap OUT ptr if we are at the 1st queue entry */                pq->OSQOut = pq->OSQEnd;            }            pq->OSQOut--;            *pq->OSQOut = msg;                        /* Insert message into queue                     */            pq->OSQEntries++;                         /* Update the nbr of entries in the queue        */            OS_EXIT_CRITICAL();        }        return (OS_NO_ERR);    }}/*$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 mailbox**              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.**********************************************************************************************************/INT8U OSQQuery (OS_EVENT *pevent, OS_Q_DATA *pdata){    OS_Q   *pq;    INT8U   i;    INT8U  *psrc;    INT8U  *pdest;            OS_ENTER_CRITICAL();    if (pevent->OSEventType != OS_EVENT_TYPE_Q) {          /* Validate event block type                */        OS_EXIT_CRITICAL();        return (OS_ERR_EVENT_TYPE);    }    pdata->OSEventGrp = pevent->OSEventGrp;                /* Copy message mailbox wait list           */    psrc              = &pevent->OSEventTbl[0];    pdest             = &pdata->OSEventTbl[0];    for (i = 0; i < OS_EVENT_TBL_SIZE; i++) {        *pdest++ = *psrc++;       }    pq = (OS_Q *)pevent->OSEventPtr;    if (pq->OSQEntries > 0) {        pdata->OSMsg = pq->OSQOut;                         /* Get next message to return if available  */    } else {        pdata->OSMsg = (void *)0;    }    pdata->OSNMsgs = pq->OSQEntries;    pdata->OSQSize = pq->OSQSize;    OS_EXIT_CRITICAL();    return (OS_NO_ERR);}void *OSIntMemGet (OS_MEM *pmem, INT8U *err){    void    *pblk;    if (pmem->OSMemNFree > 0) {                       /* See if there are any free memory blocks       */        pblk                = pmem->OSMemFreeList;    /* Yes, point to next free memory block          */        pmem->OSMemFreeList = *(void **)pblk;         /*      Adjust pointer to new free list          */        pmem->OSMemNFree--;                           /*      One less memory block in this partition  */        *err = OS_NO_ERR;                             /*      No error                                 */        return (pblk);                                /*      Return memory block to caller            */    } else {        *err = OS_MEM_NO_FREE_BLKS;                   /* No,  Notify caller of empty memory partition  */        return ((void *)0);                           /*      Return NULL pointer to caller            */    }}INT8U OSIntQPost (OS_EVENT *pevent, void *msg){    OS_Q   *pq;    if (pevent->OSEventType != OS_EVENT_TYPE_Q) {     /* Validate event block type                     */        return (OS_ERR_EVENT_TYPE);    }    if (pevent->OSEventGrp) {                         /* See if any task pending on queue              */        OSEventTaskRdy(pevent, msg, OS_STAT_Q);       /* Ready highest priority task waiting on event  */        OSIntSched();                                    /* Find highest priority task ready to run       */        return (OS_NO_ERR);    } else {        pq = (OS_Q  *)(pevent->OSEventPtr);                      /* Point to queue control block                  */        if (pq->OSQEntries >= pq->OSQSize) {          /* Make sure queue is not full                   */            return (OS_Q_FULL);        } else {            *pq->OSQIn++ = msg;                       /* 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;            }        }        return (OS_NO_ERR);    }}#endif