Code: DC14 Subject: SYSTEM SOFTWARE & OPERATING SYSTEMS
Time: 3 Hours Max. Marks: 100
NOTE: There are 9 Questions in all.
· Question 1 is compulsory and carries 20 marks. Answer to Q. 1. must be written in the space provided for it in the answer book supplied and nowhere else.
·
Out of
the remaining EIGHT Questions answer any FIVE Questions. Each question carries
16 marks.
· Any required data not explicitly given, may be suitably assumed and stated.
Q.1 Choose the correct or best alternative in the following: (2x10)
a. Program generation activity aims at
(A) Automatic generation of program
(B) Organize execution of a program written in PL
(C) Skips generation of program
(D) Speedens generation of program
b. Which amongst the following is not an advantage of Distributed systems?
(A) Reliability (B) Incremental growth
(C) Resource sharing (D) None of the above
c. An imperative statement
(A) Reserves areas of memory and associates names with them
(B) Indicates an action to be performed during execution of assembled program
(C) Indicates an action to be performed during optimization
(D) None of the above
d. Which of the following loader is executed when a system is first turned on or restarted
(A) Boot loader (B) Compile and Go loader
(C) Bootstrap loader (D) Relating loader
e. Poor response time is usually caused by
(A) Process busy
(B) High I/O rates
(C) High paging rates
(D) Any of the above
f. “Throughput” of a system is
(A) Number of programs processed by it per unit time
(B) Number of times the program is invoked by the system
(C) Number of requests made to a program by the system
(D) None of the above
g. The “blocking factor” of a file is
(A) The number of blocks accessible to a file
(B) The number of blocks allocated to a file
(C) The number of logical records in one physical record
(D) None of the above
h. Which of these is a component of a process precedence sequence?
(A) Process name (B) Sequence operator ‘;’
(C) Concurrency operator ‘,’ (D) All of the above
i. Which amongst the following is valid syntax of the Fork and Join Primitive?
(A) Fork <label> (B) Fork <label>
Join <var> Join <label>
(C) For <var> (D) Fork <var>
Join <var> join <var>
j. Nested Macro calls are expanded using the
(A) FIFO rule (First in first out) (B) LIFO (Last in First out)
(C) FILO rule (First in last out) (D) None of the above
Answer any FIVE Questions out of EIGHT Questions.
Each question carries 16 marks.
Q.2 a. What are three kinds of statements that an assembly program contains? Explain with examples. (8)
b. What is parsing? Explain any three parsing techniques. (8)
Q.3 a. List down the four conditions for a deadlock. Explain. (8)
b. Draw the state diagram of a process from its creation to termination, including all transitions, and briefly elaborate every state and every transition. (8)
Q.4 Consider the following system snapshot using data structures in the Banker’s algorithm, with resources A, B, C, and D, and process P0 to P4:
Max |
Allocation |
Need | Available | ||||||||||||||||
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A |
B |
C |
D |
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A |
B |
C |
D |
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A |
B |
C |
D |
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A |
B |
C |
D |
|
P0 |
6 |
0 |
1 |
2 |
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4 |
0 |
0 |
1 |
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P1 |
1 |
7 |
5 |
0 |
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1 |
1 |
0 |
0 |
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P2 |
2 |
3 |
5 |
6 |
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1 |
2 |
5 |
4 |
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P3 |
1 |
6 |
5 |
3 |
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0 |
6 |
3 |
3 |
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P4 |
1 |
6 |
5 |
6 |
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0 |
2 |
1 |
2 |
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3 |
2 |
1 |
1 |
Using Banker’s algorithm answer the following questions.
a How many resources of type A, B, C, and D are there? (2)
b What are the contents of the Need matrix? (3)
c. Is the system in a safe state? Why (4)
d. If a request from process P4 arrives for additional resources of (1,2,0,0,), can the Banker’s algorithm grant the request immediately? Show the new system state and other criteria. (7)
Q.5 a. Define the following
(i) Process;
(ii) Process Control Block; (PCB)
(iii) Multiprograming;
(iv) Time sharing. (8)
b. Why are Translation Look-aside Buffers (TLBs) important? In a simple paging system, what information is stored in a typical TLB table entry? (8)
Q.6 a. Why is segmented paging important (as compared to a paging system)? What are the different pieces of the virtual address in a segmented paging? (6)
b. Consider the situation in which the disk read/write head is currently located at track 45 (of tracks 0-255) and moving in the positive direction.
Assume that the following track requests have been made in this order: 40, 67, 11, 240, 87. What is the order in which optimised C-SCAN would service these requests and what is the total seek distance? (6)
c. What is encryption of
data? Identify and discuss the different classification techniques of
encrypting data? (4)
Q.7 a. Explain any three policies for process scheduling that uses resource consumption information. What is response ratio? (8)
b. Explain the three fundamental file organizations used in practice. Explain in what type of applications these files are used. (4)
c. What is a semaphore? Explain a binary semaphore with the help of an example? (4)
Q.8 a. Consider the following page reference and reference time strings for a program:
Page reference string: 5,4,3,2,1,4,3,5,4,3,2,1,5,…..
Show how pages will be allocated using the FIFO page replacement policy. Also calculate the total number of page faults when allocated page blocks are 3 and 4 respectively. (8)
b. What are the different parameter passing mechanisms to a function? Explain with the help of example? (8)
Q.9 a What are the components of a Linux operating system? The Linux source code is freely available over the Internet. What are the three implications of this availability for security of the Linux system? (8)
b What is meant by inter process communication? Explain the two fundamental models of inter process communication. (8)