rts file

CS – 324 REAL TIME SYSTEMS ( ELECTIVE I )

External Marks: 60 L T P

Internal Marks: 40 3 1 -

Total Marks: 100

Introduction: Definition, Issues in Real Time Computing, Structure of a Real Time System. Task Classes

Characterizing Real Time Systems and Tasks: Introduction, Performance measures for real time systems: Traditional performance measures, Performability, Cost functions and hard Deadlines (1)

Task Assignment and Scheduling: Introduction , Classical Uniprocessor scheduling algorithms: Rate Monotonic, EDF algorithm, Task assignment, Fault tolerant Scheduling(2)

Real Time Databases: Basic definitions, Real time Vs General Purpose databases, Main Memory databases, concurrency control issues, databases for hard real time systems(7)

Real Time Communication: Introduction, Architectural Issues, Protocols: Contention based protocols, Token based protocols, Deadlines based protocols, Stop and Go Multihop protocol, The polled bus protocol, Hierarchical round robin protocol. (module 6)

References:

1. "Real Time Systems"-Liu Pearson Education

2. "Real ?Time Systems"-C. M. Krishna and Kang G. Shin

Name of Institute: Bahra Group Of Institutes , Patiala Campus

LESSON PLAN Deptt.: computer science

Subject: real time system

Code: Class: CS-324 Sem: 6th

Total number of Topics/Practicals to be discussed as per syllabus requirements: Subject In charge:

Sr. No Topic Number of Lectures/Tutorials classes to be held/ Number of Laboratory class to be held

Date Cumulative Lecture/ Practicals

Definition, Issues in Real Time Computing, Structure of a Real Time System. Task Classes

7 2/1/12- 12/1/12

Introduction, Performance measures for real time systems: Traditional performance measures, Performability, Cost functions and hard Deadlines

8 14/1/12- 26/1/12

Classical Uniprocessor scheduling algorithms: Rate Monotonic, EDF algorithm, Task assignment, Fault tolerant Scheduling

10 31/1/12- 15/2/12

Basic definitions, Real time Vs General Purpose databases, Main Memory databases, concurrency control issues, databases for hard real time systems

12 17/2/12- 29/2/12

Architectural Issues, 7 1/3/12-

Protocols: Contention based protocols, Token based protocols,

4 16/3/12 17/3/12—23/3/12

BAHRA GROUP OF INSTITUTES PATIALA CAMPUS

REAL TIME SYSTEM (CS-324)

ASSIGNMENT NO – 1

Q1. Define real time system. How it is different from other computer system?. Q2. Explain the architecture of RTS with the help of diagram. Q3. What are the various applications of RTS? Q4. Explain the various characteristics of RTS. Q5. Differentiate between hard, soft, firm real time system.

BAHRA GROUP OF INSTITUTES PATIALA CAMPUS

REAL TIME SYSTEM (CS-324)

ASSIGNMENT NO – 2

Q1.What is the various traditional performance measures of RTS? Q2. What are the various architecture issue of RTS. Q3. How hard deadlines are performance measures for RTS. Q4. Explain various scheduling algorithms used in RTS.

BAHRA GROUP OF INSTITUTES PATIALA CAMPUS

REAL TIME SYSTEM (CS-324)

ASSIGNMENT NO – 3

Q1.What is the difference between RTS databases and general purpose databases Q2. Write and compare between contention based and token based protocols. Q3. What is the principle behind stop and go protocol? Q4. How the concurrent process can be controlled in RTS? Q5. Write a short note on main memory databases of RTS.

Question bank (RTS)

1. From point of view of requirements, how is a real-time operating system different from general purpose operating system?

2. What is a hard real-time system and how can we differentiate it from a soft realtime system?

3. How does a device drive in a RTOS differ from the usual? 4. What is a micro-kernel? 5. What is an embedded system? Give at least two examples of embedded systems. 6. Describe the general strategy to define priority structure in a RTOS. 7. How does one determine “schedulability” in RTOS? In which context it is required? 8. Describe the following policies.

a. Earliest deadline first b. Least laxity first

9. What is rate monotonic scheduling? When is its use recommended? 10. Define the essential properties of the following types of operating systems.

a. Real time b. Hand held c. Main frame d. Tightly coupled system

11. What is priority inversion? How does it manifest it self in practice? 12. How can one resolve the problem of priority inversion? 13. Explain what are all the steps that need to be taken once an interrupt occurs in embedded

system architecture. 14. Why less buffer space is required in warmhole switching? 15. Explain, atleast three uni-processor scheduling algorithms in brief. 16. How Fault-tolerance is managed by properly using redundancy? 17. Why does it become difficult to predict the response time of transactions? 18. Explain briefly what do you understand by rollback and recovery. Why can’t hard real

time systems use rollback for error detection/recovery? 19. How can fault-tolerant communication be achieved in the presence of link and node

failures? 20. Explain how absolute and relative consistency differs? 21. How is each node in a network guaranteed timely access to the networks? Explain

Timetoken protocol in detail with a flow chart. 22. What are the properties of performance measures for control computers? 23. Explain the difference between Clock-Driven Scheduling and Priority Driven Scheduling

of periodic tasks. 24. Suppose that a system is in an unsafe state. Show that it is possible for the processes to

complete their execution without entering a deadlock state. 25. Why is the polling latency typically faster than the interrupt latency?

26. By giving state diagram of the fault classes, explain the causes for different types of faults and their remedies.

27. What are the various methods of concurrency control? Which of these may lead to deadlock and why?

28. Prove that the Rate monotonic algorithm is an optimal static-priority algorithm. 29. CSMA is an efficient communication scheme in case of end-to-end transmission delay is

much less than the average time to transmit a packet and when the load is not very high but not for priority algorithm. In this context, explain, Virtual Time Carrier Sensed multiple Access (VTCSMA) with the helps of real-diagram of virtual clock in VTCSMA.

30. What is the difference between multitasking and multiprocessing?

31. What are the various features of distributed o.s.?

32. What is a real time o.s? With eg.

33. Define throughput.

34. What is an o.s?

35. What do you understand by spooling?