INT8U    err;    OS_TCB  *ptcb;    if (prio == OS_IDLE_PRIO) {                                 /* Not allowed to delete idle task     */        return (OS_TASK_DEL_IDLE);    }    if (prio >= OS_LOWEST_PRIO && prio != OS_PRIO_SELF) {       /* Task priority valid ?               */        return (OS_PRIO_INVALID);    }    if (prio == OS_PRIO_SELF) {                                 /* See if a task is requesting to ...  */        OS_ENTER_CRITICAL();                                    /* ... this task to delete itself      */        stat = OSTCBCur->OSTCBDelReq;                           /* Return request status to caller     */        OS_EXIT_CRITICAL();        return (stat);    } else {        OS_ENTER_CRITICAL();        if ((ptcb = OSTCBPrioTbl[prio]) != (OS_TCB *)0) {       /* Task to delete must exist           */            ptcb->OSTCBDelReq = OS_TASK_DEL_REQ;                /* Set flag indicating task to be DEL. */            err               = OS_NO_ERR;        } else {            err               = OS_TASK_NOT_EXIST;              /* Task must be deleted                */        }        OS_EXIT_CRITICAL();        return (err);    }}#endif/*$PAGE*//***********************************************************************************************************                                        RESUME A SUSPENDED TASK** Description: This function is called to resume a previously suspended task.  This is the only call that*              will remove an explicit task suspension.** Arguments  : prio     is the priority of the task to resume.** Returns    : OS_NO_ERR                if the requested task is resumed*              OS_PRIO_INVALID          if the priority you specify is higher that the maximum allowed *                                       (i.e. >= OS_LOWEST_PRIO)*              OS_TASK_RESUME_PRIO      if the task to resume does not exist*              OS_TASK_NOT_SUSPENDED    if the task to resume has not been suspended**********************************************************************************************************/#if OS_TASK_SUSPEND_ENINT8U OSTaskResume (INT8U prio){    OS_TCB   *ptcb;    if (prio >= OS_LOWEST_PRIO) {                               /* Make sure task priority is valid    */        return (OS_PRIO_INVALID);    }    OS_ENTER_CRITICAL();    if ((ptcb = OSTCBPrioTbl[prio]) == (OS_TCB *)0) {           /* Task to suspend must exist          */        OS_EXIT_CRITICAL();        return (OS_TASK_RESUME_PRIO);    } else {        if (ptcb->OSTCBStat & OS_STAT_SUSPEND) {                           /* Task must be suspended   */            if (((ptcb->OSTCBStat &= ~OS_STAT_SUSPEND) == OS_STAT_RDY) &&  /* Remove suspension        */                 (ptcb->OSTCBDly  == 0)) {                                 /* Must not be delayed      */                OSRdyGrp               |= ptcb->OSTCBBitY;                 /* Make task ready to run   */                OSRdyTbl[ptcb->OSTCBY] |= ptcb->OSTCBBitX;                OS_EXIT_CRITICAL();                OSSched();            } else {                OS_EXIT_CRITICAL();            }            return (OS_NO_ERR);        } else {            OS_EXIT_CRITICAL();            return (OS_TASK_NOT_SUSPENDED);        }    }}#endif/*$PAGE*//***********************************************************************************************************                                             STACK CHECKING ** Description: This function is called to check the amount of free memory left on the specified task's*              stack.** Arguments  : prio     is the task priority**              pdata    is a pointer to a data structure of type OS_STK_DATA.** Returns    : OS_NO_ERR           upon success*              OS_PRIO_INVALID     if the priority you specify is higher that the maximum allowed *                                  (i.e. > OS_LOWEST_PRIO) or, you have not specified OS_PRIO_SELF.*              OS_TASK_NOT_EXIST   if the desired task has not been created*              OS_TASK_OPT_ERR     if you did NOT specified OS_TASK_OPT_STK_CHK when the task was created**********************************************************************************************************/#if   OS_TASK_CREATE_EXT_ENINT8U OSTaskStkChk (INT8U prio, OS_STK_DATA *pdata){    OS_TCB  *ptcb;    OS_STK  *pchk;    INT32U   free;    INT32U   size;    pdata->OSFree = 0;                                          /* Assume failure, set to 0 size       */    pdata->OSUsed = 0;    if (prio > OS_LOWEST_PRIO && prio != OS_PRIO_SELF) {        /* Make sure task priority is valid    */        return (OS_PRIO_INVALID);    }    OS_ENTER_CRITICAL();    if (prio == OS_PRIO_SELF) {                        /* See if check for SELF                        */        prio = OSTCBCur->OSTCBPrio;    }    ptcb = OSTCBPrioTbl[prio];    if (ptcb == (OS_TCB *)0) {                         /* Make sure task exist                         */        OS_EXIT_CRITICAL();        return (OS_TASK_NOT_EXIST);    }    if ((ptcb->OSTCBOpt & OS_TASK_OPT_STK_CHK) == 0) { /* Make sure stack checking option is set       */        OS_EXIT_CRITICAL();        return (OS_TASK_OPT_ERR);    }    free = 0;    size = ptcb->OSTCBStkSize;    pchk = ptcb->OSTCBStkBottom;    OS_EXIT_CRITICAL();#if OS_STK_GROWTH == 1    while (*pchk++ == 0) {                            /* Compute the number of zero entries on the stk */        free++;    }#else    while (*pchk-- == 0) {        free++;    }#endif    pdata->OSFree = free * sizeof(OS_STK);            /* Compute number of free bytes on the stack     */    pdata->OSUsed = (size - free) * sizeof(OS_STK);   /* Compute number of bytes used on the stack     */    return (OS_NO_ERR);}#endif/*$PAGE*//***********************************************************************************************************                                            SUSPEND A TASK** Description: This function is called to suspend a task.  The task can be the calling task if the*              priority passed to OSTaskSuspend() is the priority of the calling task or OS_PRIO_SELF.** Arguments  : prio     is the priority of the task to suspend.  If you specify OS_PRIO_SELF, the*                       calling task will suspend itself and rescheduling will occur.** Returns    : OS_NO_ERR                if the requested task is suspended*              OS_TASK_SUSPEND_IDLE     if you attempted to suspend the idle task which is not allowed.*              OS_PRIO_INVALID          if the priority you specify is higher that the maximum allowed *                                       (i.e. >= OS_LOWEST_PRIO) or, you have not specified OS_PRIO_SELF.*              OS_TASK_SUSPEND_PRIO     if the task to suspend does not exist** Note       : You should use this function with great care.  If you suspend a task that is waiting for*              an event (i.e. a message, a semaphore, a queue ...) you will prevent this task from*              running when the event arrives.**********************************************************************************************************/#if OS_TASK_SUSPEND_ENINT8U OSTaskSuspend (INT8U prio){    BOOLEAN   self;    OS_TCB   *ptcb;    if (prio == OS_IDLE_PRIO) {                                 /* Not allowed to suspend idle task    */        return (OS_TASK_SUSPEND_IDLE);    }    if (prio >= OS_LOWEST_PRIO && prio != OS_PRIO_SELF) {       /* Task priority valid ?               */        return (OS_PRIO_INVALID);    }    OS_ENTER_CRITICAL();    if (prio == OS_PRIO_SELF) {                                 /* See if suspend SELF                 */        prio = OSTCBCur->OSTCBPrio;        self = TRUE;    } else if (prio == OSTCBCur->OSTCBPrio) {                   /* See if suspending self              */        self = TRUE;    } else {        self = FALSE;                                           /* No suspending another task          */    }    if ((ptcb = OSTCBPrioTbl[prio]) == (OS_TCB *)0) {                /* Task to suspend must exist     */        OS_EXIT_CRITICAL();        return (OS_TASK_SUSPEND_PRIO);    } else {        if ((OSRdyTbl[ptcb->OSTCBY] &= ~ptcb->OSTCBBitX) == 0) {     /* Make task not ready            */            OSRdyGrp &= ~ptcb->OSTCBBitY;        }        ptcb->OSTCBStat |= OS_STAT_SUSPEND;                          /* Status of task is 'SUSPENDED'  */        OS_EXIT_CRITICAL();        if (self == TRUE) {                                          /* Context switch only if SELF    */            OSSched();        }        return (OS_NO_ERR);    }}#endif/*$PAGE*//***********************************************************************************************************                                            QUERY A TASK** Description: This function is called to obtain a copy of the desired task's TCB.** Arguments  : prio     is the priority of the task to obtain information from.  ** Returns    : OS_NO_ERR       if the requested task is suspended*              OS_PRIO_INVALID if the priority you specify is higher that the maximum allowed *                              (i.e. > OS_LOWEST_PRIO) or, you have not specified OS_PRIO_SELF.*              OS_PRIO_ERR     if the desired task has not been created **********************************************************************************************************/INT8U OSTaskQuery (INT8U prio, OS_TCB *pdata){    OS_TCB *ptcb;    if (prio > OS_LOWEST_PRIO && prio != OS_PRIO_SELF) {   /* Task priority valid ?                    */        return (OS_PRIO_INVALID);    }    OS_ENTER_CRITICAL();    if (prio == OS_PRIO_SELF) {                            /* See if suspend SELF                      */        prio = OSTCBCur->OSTCBPrio;    }    if ((ptcb = OSTCBPrioTbl[prio]) == (OS_TCB *)0) {      /* Task to query must exist                 */        OS_EXIT_CRITICAL();        return (OS_PRIO_ERR);    }    *pdata = *ptcb;                                        /* Copy TCB into user storage area          */    OS_EXIT_CRITICAL();    return (OS_NO_ERR);}