Deck 8: System Software

Question 1

Microkernels attempt to provide as small a kernel as possible, putting much of the operating system support into additional modules. What do you feel are the minimum services that the kernel must provide

Answer 1

Micro Kernel:
Micro kernel divides the program or process into small number of processes, only basic processes running in kernel space and other processes running at user space. But this is not minimizing the services that the kernel must provide. Because the communication between the processes in user space and kernel space done with the help of message passing technique but processing is bit slowly compare to monolithic kernel.
The microkernel approach defines a simple abstraction over the hardware, with a set of primitives or system calls to implement minimal OS services.
A microkernel must provide an abstraction of the security-relevant mechanisms of the hardware. That means it must provide:
• an abstraction of hardware address spaces
• an abstraction of execution on the CPU,
• a mechanism for communication with security.
They must provide some minimal OS services such as memory management, multitasking, and inter-process communication.
Finally, the microkernel must provide mechanisms corresponding to hardware features. It need not provide services but must provide just fundamental mechanisms.

Question 2

What problems does an assembler have to overcome in order to produce complete binary code in one pass over the source file How would code written for a one-pass assembler be different from code written for a two-pass assembler

Answer 2

NO ANSWER

Question 3

The Java bytecode for access to the local variable array for a class is at most two bytes long. One byte is used for the opcode; the other indicates the offset into the array. How many variables can be held in the local variable array What do you think happens when this number is exceeded

Answer 3

Local Variable Array
In Java, local variables are stored in array and this array contains information about the data type of each of the variables of a class and the initial value of the variable. Consider java uses 8-bit indexer and maximum 255 variables can be held in the local variable array.
If this number is exceeded, it gets the array length and sets the new index for that array.

Question 4

What is the salient feature of the Java programming language that provides for its portability across disparate hardware environments

Question 5

What improvements to computer operations were brought about by resident monitors

Question 6

What are the benefits and drawbacks to a GUI operating system interface

Question 7

The operating system and a user program hold two different perceptions of a virtual machine. Explain how they differ.

Question 8

Assemblers produce machine code that is executable after it has been link edited. Java compilers produce _________ that is interpreted during its execution.

Question 9

If you were writing code for a real-time operating system, what restrictions might you want to impose on the system Hint: Think about the types of things that cause unpredictable reaction times. (How might a memory access be delayed, for example )

Question 10

Why should assembly language be avoided for general application development Under what circumstances is assembly language preferred or required

Question 11

Java is called an interpreted language, yet Java is a compiled language that produces a binary output stream. Explain how this language can be both compiled and interpreted.

Question 12

What is a magic number that identifies a Java class file

Question 13

With regard to printer output, how was the word spool derived

Question 14

How is long-term process scheduling different from short-term process scheduling

Question 15

What is the difference between a subsystem and a logical partition

Question 16

How is a logical database schema different from a physical database schema

Question 17

What is the difference between multiprogramming and multiprocessing Multiprogramming and multithreading

Question 18

Under what circumstances would you argue in favor of using assembly language code for developing an application program

Question 19

We stated that the performance of a Java program running in the JVM cannot possibly match that of a regular compiled language. Explain why this is so.

Question 20

Which data structure is most commonly used to index databases

Question 21

Describe how multiprogramming systems differ from timesharing systems.

Question 22

What is meant by preemptive scheduling

Question 23

Name some advantages of server consolidation. Is server consolidation a good idea for every enterprise

Question 24

Why are database reorganizations necessary

Question 25

Under what circumstances is it desirable to collect groups of processes and programs into subsystems running on a large computer What advantages would there be to creating logical partitions on this system

Question 26

What are the advantages of using a compiled language over an interpreted one Under what circumstances would you choose to use an interpreted language

Question 27

Answer the following with respect to database processing:
a) What is a race condition Give an example.
b) How can race conditions be prevented
c) What are the risks in race condition prevention

Question 28

Explain the ACID properties of a database system.

Question 29

What is the most critical factor in the operation of hard real-time systems

Question 30

Which method of process scheduling is most useful in a timesharing environment

Question 31

Describe the programming language hierarchy. Why is a triangle a suitable symbol for representing this hierarchy

Question 32

What is a race condition

Question 33

What advantages would there be to using both subsystems and logical partitions on the same machine

Question 34

Discuss the following questions relative to compilers:
a) Which phase of a compiler would give you a syntax error
b) Which phase complains about undefined variables
c) If you try to add an integer to a character string, which compiler phase would emit the error message

Question 35

In what ways are n-tiered transaction processing architectures superior to single-tiered architectures Which usually costs more

Question 36

Database logs serve two purposes. What are they

Question 37

Multiprocessor systems can be classified by the way in which they communicate. How are they classified in this chapter

Question 38

Which process scheduling method is provably optimal

Question 39

How does absolute code differ from relocatable code

Question 40

What services do transaction managers provide

Question 41

When is it appropriate to use nonrelocatable binary program code Why is relocatable code preferred

Question 42

Why is the execution environment of a Java class called a virtual machine How does this virtual machine compare to a real machine running code written in C

Question 43

To improve performance, your company has decided to replicate its product database across several servers so that not all transactions go through a single system. What sorts of issues will need to be considered

Question 44

How is a distributed operating system different from a networked operating system

Question 45

Describe the steps involved in performing a context switch.

Question 46

What is the purpose of a link editor How is it different from a dynamic link library

Question 47

Suppose there were no such thing as relocatable program code. How would the process of memory paging be made more complex

Question 48

Why do you suppose the method area of a JVM is global to all of the threads running in the virtual machine environment

Question 49

We said that the risk of deadlock is always present anytime a system resource is locked. Describe a way in which deadlock can occur.

Question 50

What is meant by transparency

Question 51

Besides process management, what are the other two important functions of an operating system

Question 52

Describe the purpose of each phase of a compiler.

Question 53

What do you feel are the limitations of a computer that has no operating system How would a user load and execute a program

Question 54

Discuss the advantages and disadvantages of dynamic linking.

Question 55

We stated that only one method at a time can be active within each thread running in the JVM. Why do you think this is the case

Question 56

Research various command line interfaces (such as Unix, MS-DOS, and VMS) and different windows interfaces (such as any Microsoft Windows product, MacOS, and KDE).
a) Consider some of the major commands, such as getting a directory listing, deleting a file, or changing directories. Explain how each of these commands is implemented on the various operating systems you studied.
b) List and explain some of the commands that are easier using a command line interface versus using a GUI. List and explain some of the commands that are easier using a GUI versus using a command line interface.
c) Which type of interface do you prefer Why

Question 57

What was the main objective of early operating systems as compared to the goals of today's systems

Question 58

Describe the two divergent philosophies concerning operating system kernel design.

Question 59

What is an overlay Why are overlays no longer needed in large computer systems

Question 60

How does an interpreter differ from a compiler