Q.1. Answer following questions in short and to the point only.
(a) What are the strategies, kernel chooses for handling aperiodic and sporadic jobs?
(b) What are the advantages of modular programming in RTS ?
(c) How redundancies are provided in preventive type of fault-tolerant systems?
(d) Discuss in short, advantages and disadvantages of static and dynamic memory allocation.
(e) Why semaphores are important in RTOS?
Q.2. A system of four tasks T1 = (4,1), T2 = (10,2), T3 = (12,2) T4 = (30,3) is scheduled with executive cyclic clock driven scheduling algorithm. A stream of sporadic jobs arrives as follows, Si = {(2,2,16) ;(18,4,32); (18,3,28)}
(a) Schedule these sporadic jobs applying acceptance test.
(b) Draw neat schedule up to 10 frames showing accepted sporadic jobs scheduled.
Q.3. A system of five periodic tasks Ti {(5, 1); (7, 1); (8, 1); (12, 1.5); (25, 4)} is found to be schedulable using RMA. Now find out the maximum value of context switch 'CS', such that the system remains schedulable.
Q.4. A set of hard real-time periodic tasks need to be scheduled using RMA. The following table contains the details of these tasks and their use of shared resources. Can all the tasks meet their respective deadlines when priority ceiling protocol is used for resource scheduling?
|
Task
|
Pi
|
ei
|
R1
|
R2
|
R3
|
R4
|
R5
|
|
T1
|
50
|
15
|
6
|
7
|
--
|
10
|
3
|
|
T2
|
100
|
25
|
--
|
--
|
--
|
8
|
--
|
|
T3
|
150
|
40
|
4
|
14
|
8
|
--
|
10
|
|
T4
|
200
|
35
|
--
|
--
|
--
|
--
|
--
|
|
T5
|
250
|
50
|
6
|
11
|
--
|
9
|
7
|
Q.5. Use Petri Net for 2x2 matrix multiplication. Write all the places and transitions clearly. Write firing table also.