Task dependent synchronization: Sleep Task, Wake-up Task and Cancel Wake-up

Sleep Task

ER tslp_tsk(TMO tmout)
{

        Sanity check of context and arguments
        if (interrupt context or dispatch disabled state or Timer or overrun
         handlers)
                return E_CTX;

        Take Task ID of current running task
        Take TCB
        Enter critical section
        Take number of pending wakeups
        if (No pending wakeup) {
                if (Not polling) {
                        if (timeout is NOT FOREVER) {
                                add taks to timer queue;
                                make tcb status as SLEEP with TIMEOUT
                        } else /* forever timeout */
                                make tcb status just as SLEEP
                        }
                        remove task from Ready queue and dispatch
                        /* critical section is exit inside dispatch */
                        return error code from dispatch;
                }
                /* else, Polling */ {
                Exit critical section and return E_TMOUT; /* ?? Not needed */
                /* No polling service call is provided for slp_tsk- ITRON spec */
        }
        /* else, pending wakeups */
        Decrement the number of pending wake-ups by 1
        Exit critical section and return E_OK;
}

Wakeup Task

ER wup_tsk(ID tskid)
{
        if (tskid is TSK_SELF)
                Take taskid from Ready Queue[0]
        if (Task ID is greater than maximum of Task ID)
                return E_ID;
        Enter critical section
        Take TCB
        if (TCB == NULL)
                return E_NOEXS;
        Take status from TCB
        if (status is sleeping) {
                make the status as Ready
                if (Sleeping with TIMEOUT)
                        remove task from Timer queue
                if (Not suspended) {
                        add task to ready queue and dispatch
                        return;
                } /* Else, suspended */
                Exit critical section and just return E_OK;
        }
        /* Not sleeping */
        if (status is not Dormant) {
                increment pending wakeup count
                if (pending wakeup count does not exceed maximum)
                        exit critical section and return E_OK
                /* else, exceeded */
                assign wakeup count to the maximum
                exit critical section and return E_QOVR;
        }
        /* Dormant */
        exit critical section and return E_OBJ;
}

Cancel Wakeup Task

ER can_wup(ID tskid)
{
        if (tskid is TSK_SELF)
                Take taskid from Ready Queue[0]
        if (Task ID is greater than maximum of Task ID)
                return E_ID;
        Enter critical section
        Take TCB
        if (TCB == NULL)
                return E_NOEXS;
        else if (Task status is Dormat)
                return E_OBJ;
        else {
                Take backup of number of pending wakeup requests
                make pending wakeup counts as zero
        }
        Exit critical section
        return saved wake up counts;
}