Consider the processes $P_1$ to $P_5$ with the following service times $d_i,$ arrival times $a_i,$

and priorities $p_i$ :

A single$-$processor$/$single core system is used and the time quantum is $4.$ Visualise

for the scheduling algorithms below the resulting schedules using a Gantt chart and

calculate the average residence time and the average waiting time:

$($a$)$ First Come First Serve $($FCFS$),$

$($b$)$ Shortest Job First $($SJF$),$

$($c$)$ Shortest Remaining Time First $($SRTF$),$

$($d$)$ Round Robin $($RR$),$

$($e$)$ Round Robin with priorities $(R{R}_{\text{p}\text{r}\text{i}\text{o}}).$

$($A note concerning round$-$robin scheduling: as said on the slides, newly arrived processes

are appended to the tail of the ready queue; furthermore, if a new process $($even one

with a higher priority$)$ arrives, another process that has already started its time slice is

allowed to continue.$)$