Task Management: Get priority, Reference to Task State

Acquire Task Priority

ER get_pri(ID tskid, PRI *p_tskpri)
{
        if (tskid is TSK_SELF)
                Take taskid from Ready Queue[0]
        if (Task ID is greater than maximum of Task ID)
                return E_ID;
        if (called from ISR and specified task id as SELF)
                return E_ID;

        if (task id is currently running one) {
                assign p_tskpri = Running priority from TCB;
                return E_OK
        }

        /* For any other task */
        Enter critical section;
        Take TCB
        if (TCB == NULL)
                return E_NOEXS;
        if (Task status is Dormat)
                return E_OBJ;
        assign p_tskpri = Running priority from TCB;
        Exit critical section
        return E_OK;
}

Reference Task State

ER ref_tsk(ID tskid, T_RTSK *pk_rtsk)
{

        if (Task ID is greater than maximum of Task ID)
                return E_ID;
        Enter critical section;

        if (tskid is TSK_SELF)
                Take taskid from Ready Queue[0]
        Take TCB
        if (TCB == NULL)
                return E_NOEXS;

        Fill out following information from TCB
        pk_rtsk->tskpri
        pk_rtsk->tskbpri
        pk_rtsk->actcnt

        Take task status from TCB
        if (status is Dormant) {
                Exit critical section
                pk_rtsk->tskstat = TTS_DMT;
                Fill out all other fields with Zero.
                return E_OK;
        }

        Assign pk_rtsk->wupcnt from TCB;
        if (status is Ready) {
                if (Task is currently running) {
                        exit critical sections
                        Fill pk_rtsk->tskstat = TTS_RUN;
                        Fill suspension count as zero
                } else /* Not currently running */ {
                        Take suspension status from TCB
                        Exit critical section
                        Fill pk_rtsk->suscnt with the suspension count
                        If (task is not suspended)
                                Assign task state as TTS_RDY;
                        else
                                Assign task state as TTS_SUS;
                }
                /* Assign the following fields as zero */
                pk_rtsk->tskwait = 0;
                pk_rtsk->lefttmo = 0;
                pk_rtsk->wobjid = 0;
                return E_OK;
        }
        /* Status is not Ready */
        if (waiting in timer queue)
                assign pk_rtsk->lefttmo = TCB timeout - current system time;
        else
                assign pk_rtsk->lefttmo = TMO_FEVR;
        if (waiting in dlt_tsk call)
                pk_rtsk->wobjid = 0;
        else
                pk_rtsk->wobjid = Take the object id from the saved context;
        Take suspension status
        Exit critical section
        Assign pk_rtsk->suscnt with suspension count
        if (status is suspended)
                pk_rtsk->tskstat = WAITING state ;
        else
                pk_rtsk->tskstat = WAITING SUSPENDED state;
        Assign pk_rtsk->tskwait with WAITING Resource type
        return E_OK;
}

Simplified Reference Task State

ER ref_tst(ID tskid, T_RTST *pk_rtst)
{
        if (Task ID is greater than maximum of Task ID)
                return E_ID;
        Enter critical section;

        if (tskid is TSK_SELF)
                Take taskid from Ready Queue[0]
        Take TCB
        if (TCB == NULL)
                return E_NOEXS;

        Take task status from TCB
        if (status is Dormant) {
                Exit critical section
                pk_rtsk->tskstat = TTS_DMT;
                Fill out all other fields with Zero.
                return E_OK;
        }
        if (status is Ready) {
                if (Task is currently running) {
                        exit critical sections
                        Fill pk_rtsk->tskstat = TTS_RUN;
                } else /* Not currently running */ {
                        Take suspension status from TCB
                        Exit critical section
                        If (task is not suspended)
                                Assign task state as TTS_RDY;
                        else
                                Assign task state as TTS_SUS;
                }
                /* Assign the following fields as zero */
                pk_rtsk->tskwait = 0;
                return E_OK;
        }
        Take suspension status
        Exit critical section
        Assign pk_rtsk->suscnt with suspension count
        if (status is suspended)
                pk_rtsk->tskstat = WAITING state ;
        else
                pk_rtsk->tskstat = WAITING SUSPENDED state;
        Assign pk_rtsk->tskwait with WAITING Resource type
        return E_OK;
}