OS chapter 3

Question 1

What is multitasking/multiprocessing/
pseudo-parallelism?

Answer 1

The ability to apparently run two programs at the same time.

Question 2

What term refers to two processes accessing the same shared resource at the same time?

Answer 2

Race conditions

Question 3

What is the difference between a program and a process?

Answer 3

A program may not be running but a process is actually running.

Question 4

The IBM 1401 and 7094 computers are examples of which generation of computing?

Answer 4

Second generation

Question 5

__________ scheduling ensures that a job is done when promised.

Answer 5

Guaranteed

Question 6

Most modern systems use ____________.

Answer 6

preemptive multitaskiing

Question 7

Which of the following is NOT one of the three (3) process states?

Blocked
Ready
Running
All of these are process states

Answer 7

All

Question 8

___________ scheduling allots a time period called a quantum for each process.

Answer 8

Round Robin

Question 9

A _________ is a running program along with data, stack, program counter, stack pointer and other registers.

Answer 9

process

Question 10

What does the OS keep track of processes with and what information is kept?

Answer 10

A table that keeps the state, program counter, stack pointer, memory allocation, file status, etc.

Question 11

How do processes communicate?

Answer 11

Interprocess communication.

Question 12

How is interprocess communication used?

Answer 12

There are multiple means, one being with interrupts, letting the processor know its time to switch processes.

Question 13

Describe the process of running multiple processes: A, B, C, and D concurrently.

Answer 13

A runs first, then B runs, then C, Then D, then it wraps back around to A, cycling through until the processes finish. No two run at the same time.

Question 14

What is a process tree?

Answer 14

It describes the relationship between parent child processes. Some processes spawn other processes, which are called child processes.

Question 15

What is a ready process?

Answer 15

A process that could run, but is not on its turn.

Question 16

What is a blocked process?

Answer 16

A blocked process has been running but is waiting for a device such as
a printer or a disk drive.

Question 17

What is the critical section of a process?

Answer 17

The point where it accesses shared resources.

Question 18

What is mutual exclusion?

Answer 18

When you lock out processes from accessing an in-use resource.

Question 19

What are the different process priority criteria and what do they mean?

Answer 19

Fairness - each process gets equal share of the CPU time.
Efficiency - keep the CPU busy.
Response time minimal for interactive users.
Turnaround minimal for batch users.
Throughput - maximize number of jobs per hour.

Question 20

What kinds of process scheduling do computers use?

Answer 20

run-to-completion scheduling
preemptive multitasking
cooperative multitasking

Question 21

What is preemptive multitasking?

Answer 21

A system that has a process run for a set maximum amount of time, and then interrupts it for another process to begin.

Question 22

Types of process scheduling

Answer 22

Round robin
Priority
Shortest Job first
Guaranteed scheduling

Question 23

What is Priority scheduling?

Answer 23

Gives the most important job top priority.

Question 24

What is Round Robin Scheduling?

Answer 24

allots a time period called a quantum for each process.

Question 25

What is a quantum in process scheduling?

Answer 25

The length of time given to a process to run.

Question 26

What is Guaranteed scheduling?

Answer 26

ensures that a job is done when
promised.