Part II: Process Scheduling

Consider the following 4 source codes:

Source Code 1:

program My_Pgm1

i = 1

for n = 1 to 10

x = i + n

next

end

Source Code 2:

program My_Pgm2

i = 10

for n = 1 to 8

x = i + n

next

end

Source Code 3:

program My_Pgm3

i = 10

for n = 1 to 15

x = i + n

next

end

Source Code 4:

program My_Pgm4

i = 10

for n = 1 to 5

x = i - n

next

end

Create 4 processes P1, P2. P3 and P4 from source codes 1, 2, 3and 4 respectively with following properties. Fill up the following table by considering Log data only:

Scheduling Algorithm: FCFS
Process		Arrival Time		Waiting time
P1		0
P2		0
P3		0
P4		0
Average waiting time:
Scheduling Algorithm: Round Robin with time quantum 5
Process		Arrival Time		Waiting time
P1		0
P2		0
P3		0
P4		0
Average waiting time:
Scheduling Algorithm: Shortest Job First (Pre-emptive)
Process		Arrival Time	Priority	Waiting time
P1		0	1
P2		2	2
P3		6	1
P4		4	2
Average waiting time
Scheduling Algorithm: Shortest Job First (Non-Pre-emptive)
Process	Arrival Time		Priority	Waiting time
P1	0		1
P2	2		2
P3	6		3
P4	4		4
Average waiting time:
Out of three cases, which one is better and why?