Chapter 2 System Structures

Question 1

What is Resource Allocation

Answer 1

When multiple users or multiple jobs running concurrently, resources must be allocated to each of them.

Question 2

What’s some advantages of higher-level languages?

Answer 2

Code can be written faster, easier to understand and modify, improved complier technology, easier to port (to move to some other hardware platform)

Question 3

What are some disadvantages of higher-level languages in OS?

Answer 3

Reduced speed and higher storage requirements.

Question 4

Why is it a better to use APIs rather than system calls?

Answer 4

To ensure portability and hide some of the details of the system call from the application programmer.

Question 5

What are the three most common API’s

Answer 5

Win32 API , POSIX API, Java API

Question 6

What’s the purpose of System Programs?

Answer 6

Can be thought of as bundles of useful system calls. They provide basic functionality to users to they don’t have to write their own programs to solve common problems

Question 7

What’s the main advantage of the layered approach?

Answer 7

The system is easier to debug and modify since changes affect only limited sections of the system opposed to touching all sections of the operating system. Another advantage is the simplicity of it’s construction.

Question 8

What’s the purpose of the command interpreter?

Answer 8

It reads commands from the user or from a file of commands and executes them, usually by turning them into one or more system calls.

Question 9

Why is the command interpreter separate from the kernel?

Answer 9

It’s usually not apart of the kernel because the command interpreter is subject to changes.

Question 10

What are the three major activities of an operating system with regard to secondary storage management?

Answer 10

Free-space management, storage allocation, disk scheduling

Question 11

What are the three major activities of an operating system with regard to memory management?

Answer 11

Keep track of which parts of memory are currently being used and by whom, decide which processes are to be loaded into memory when memory space becomes available, allocate and deallocate memory space as needed.

Question 12

What is the purpose of system calls?

Answer 12

System calls allow user-level processes to request services of the operating system.

Question 13

What are some problems with the layered approach?

Answer 13

Appropriately defining the various layers, less efficient than other types.

Question 14

How does Solaris pass parameters?

Answer 14

Parameters stored in a block, or table in memory and address of block passed as a parameter in a register.

Question 15

What language is MS DOS written in?

Answer 15

Assembly for intel 8088, Linux in C

Question 16

What are the seven types of loadable kernel modules in a Solaris operating system structure.

Answer 16

Scheduling classes, file systems, loadable system calls, executable formats, STEAMS modules, miscellaneous, Device and bus drivers

Question 17

List two services of the file manager.

Answer 17

organizes files by importance and locates files.

Question 18

What are the three approaches used to pass parameters for system calls?

Answer 18

registers, stacks, addresses

Question 19

How are system calls implemented and why are they implemented in that manner?

Answer 19

They are implemented through the use of API’s and implemented this way because it allows for more portability, compatibility, and easier modification. Flexibility is also important as it prevents overhead.

Question 20

In the microkernel structuring, what functionality remains in the kernel?

Answer 20

Memory and Cpu management/functionality

Question 21

How are the modular and layered approach similar?

Answer 21

They both utilize object oriented functions, easy to understand and modify.

Question 22

Why is MAC OS X considered a hybrid environment?

Answer 22

It uses multiple Os environments