Assume
that
P
A
, P
B
and P
C
are three
distinguished
program
s
. When
P
A
is
executed, it
needs 10 ticks to complete its execution and it forks new
processes executing P
B
at
tick
-
marks
4 and 7. Similarly,
P
B
needs 8 ticks to
complete its execution and it forks new processes executing P
C
at
tic
k
-
marks
3
and 5
; and P
C
needs 4 ticks to complete its execution and it does an I/O a
t
tick
-
mark 2
. Assume that
I/O requests will be handled in a
first
-
come
-
first
-
serve
manner and each I/O
can be completed within 4 ticks
.
Assume that
process P
1
, which is executing program P
A
arrives at t=
0
–
.
Draw a Gantt chart
illustrating the scheduling of these processes if a
r
ound
-
r
obin
scheduling
with
a time quantum of
3
is used.