test

Question 1

What do shells do

Answer 1

allows user to interface with the OS

Question 2

What do executables need?

Answer 2

OS servicces

Question 3

How are executable performed ?

Answer 3

through system calls

Question 4

What is a process ?

Answer 4

a program in exectuion

Question 5

What is the address space of a process ?

Answer 5

memory locations which the process reads or writes to

Question 6

PSW

Answer 6

Processor Status word contains control bits in CPU

Question 7

Two modes of instructions

Answer 7

User mode = less privileged System mode = more privileged

Question 8

What is an OS exception?

Answer 8

An abrupt change in Control flow in a response to a change in processor state

Question 9

Exception: Interrupt

Answer 9

Signals from I/O

Question 10

Exceptiom:Trap

Answer 10

Application request OS services

Question 11

Exceptions:Faults

Answer 11

Recoverable error

Question 12

Exception:Aborts

Answer 12

Not recoverable error

Question 13

Kernel

Answer 13

Everything below the system call interface and above the physical hardware

Question 14

What does the Kernel provide

Answer 14

• file system, -cpu scheduling

- memory management, other os functionality

Question 15

What does a Kernel use?

Answer 15

System calls

Question 16

Three catagories of system calls

Answer 16

1 File management, 2 Process control, 3 Information manipulation

Question 17

What is a zombie

Answer 17

A process whose parent has excited/not waiting

Question 18

What do process control blocks enable

Answer 18

Allows the CPU to resume the process where it left off when switching execution

Question 19

What are the types of scheduling queues

Answer 19

job, Ready, Device

Question 20

CPU scheduler vs long term scheduler

Answer 20

CPU is short term long term will try to balance CPU and I/O demand

Question 21

What happens in context switches?

Answer 21

Old process state is saved new process is loaded

Question 22

Process creation is based around

Answer 22

parent creating children

Question 23

What is an orphan

Answer 23

Child whose parent has terminated

Question 24

Pipes allow for communication on?

Answer 24

The same machine

Question 25

Sockets allow for communication on?

Answer 25

Separate Machines

Question 26

Error control approaches

Answer 26

Parity, CRC, Hamming

Question 27

Flow Control: Stop and wait

Answer 27

Sever waits for client ack after each message

Question 28

Flow Control: Pipeling

Answer 28

Sends ACK of next frame expected

Question 29

Flow Control: Automatic Repeat Requests

Answer 29

Goes back and rejects new frames after error and ask for bad frames

Question 30

High level data link

Answer 30

Station types. Primary controls secondary

Question 31

Threads share?

Answer 31

Process Address Space and OS state

Question 32

Two categories of thread implementation

Answer 32

User level threads and kernel level threads

Question 33

Network Adress

Answer 33

Identifies a node

Question 34

Routing

Answer 34

Forwards message to desitnation

Question 35

Most networks can be broken into . . .

Answer 35

client and server and the client initiations communication

Question 36

Network communicates data to the

Answer 36

Operating system

Question 37

Operating system communicates data to the . ..

Answer 37

socket

Question 38

Socket connects data to the

Answer 38

application

Question 39

Two types of application Process communcation

Answer 39

Data gram and Stream

Question 40

Data gram Socket

Answer 40

UDP Like post mail collection of messages connectionless

Question 41

Stream socket

Answer 41

TCP Like telephone stream of bits connection oriented

Question 42

Two types of network communication

Answer 42

Circuit switching and packet switching

Question 43

Circuit switching

Answer 43

Dedicated path between two stations

Question 44

Packet switching

Answer 44

Data transmitted in short packets that also hold control information such as destination

Question 45

Security: Spread spectrum

Answer 45

Modulate the signal such that the bandwidth is increased significantly

Question 46

Security: Frequency hoping spread spectrum

Answer 46

Sequence is seemly spread on random frequency each channel is used for fixed interval

Question 47

TSL

Answer 47

Test and lock instruction

Question 48

Synchronize clocks: Christians Algorithm

Answer 48

Ask twice for time use difference to calculate delay

Question 49

Synchronize clocks: Berkely algortihm

Answer 49

Server polls client compute average time push result to client

Question 50

Synchronize clocks: Lampert

Answer 50

Uses logical reasoning to set clocks

Question 51

Resource allocation graph

Answer 51

R_1 -> P_1 resources R held by P R

Question 52

Ostrich Algorthim for deadlocks

Answer 52

ignores them

Question 53

Detecting deadlocks in a graph

Answer 53

DFS if node shows up twice deadlock is detected

Question 54

Dead lock safe state

Answer 54

State where no deadlocks can occur avoid deadlocks by staying here

Question 55

HLDLC: Normal response mode

Answer 55

+unbalanced, primary initiates, secondary only response

Question 56

HLDLC: Asynchronous balanced mode

Answer 56

+ Balanced, either station may initiate, most widely used

Question 57

HLDLC: Asynchronous Response mode

Answer 57

Unbalanced secondary initiates rare