2. About FCFS
Definition. It is the simplest CPU scheduling algorithm.
With this algorithm, processes are assigned the CPU in
the order they request it.
Basically, there is a single queue of ready processes.
Relative importance of jobs measured only by arrival
time.
The implementation of the FCFS policy is easily
managed with a FIFO queue.
When a process enters the ready queue, its PBC is linked
onto the tail of the queue.
The average waiting time under the FCFS policy,
however, is often quite long.
3. Example of FCFS
Example.
Process
AT
BT
WT
RT
TT
P2
0
3
0
0
3
P4
4
2
3
3
5
P3
6
3
3
3
6
P1
2
4
1
1
5
P2
P1
P2
0
P4
P3
AWT
P1
2
P4
3
4
6
7
P3
9
1.75
ART
1.75
ATT
4.75
