Lecture 6 (unfinished)

Question 1

What is Multi-programming in tems of OS management?

Answer 1

The management of multiple processes within a uniprocessor system

Question 2

What is Multi-processing in terms of OS management?

Answer 2

The management of multiple processes within a multiprocessor

Question 3

What is Distributed processing in terms of OS management?

Answer 3

The management of multiple processes executing on multiple, distributed computer systems

Question 4

What are the 3 different concurrency arises in different contexts?

Answer 4

Multiple Applications

Structed Applications

Operating System Structure

Question 5

What is Multiple applications in terms of Concurrency?

Answer 5

Invented to allow processing time to be shared among active applications

Question 6

What is Structured applications in terms of Concurrency?

Answer 6

Extension of modular design and structured programming

Question 7

What is Operating system structure in terms of Concurrency?

Answer 7

OS themselves implemented as a set of processes or threads

Question 8

What is Interleaving and overlapping in terms of Principles of Concurrency

Answer 8

Interleaving and overlapping
• Can be viewed as examples of concurrent processing
• Both present the same problems

Question 9

What is a Uniprocessor in terms of the principles of Concurrency?

Answer 9

Uniprocessor – the relative speed of execution of
processes cannot be predicted, and depends on:
• Activities of other processes
• The way the OS handles interrupts
• Scheduling policies of the OS

Question 10

What are 2 difficulties of Concurrency?

Answer 10

• Sharing of global resources

* Difficult for the OS to manage the allocation of resources optimally

Question 11

What are some OS Concerns?

Answer 11

The OS must:

Be able to keep track of various processes

Allocate and de-allocate resources for each active process

Question 12

What is resource Competition?

Answer 12

Concurrent processes come into conflict when
they are competing for use of the same resource
e.g. memory

Question 13

After resource competition a process trying to complete may face 3 problems which are?

Answer 13

The need for mutual exclusion
Deadlock
Starvation

Question 14

Why do we need synchornization?

Answer 14

Avoid unwanted execution sequence

Ensure integrity in data

Question 15

What is race Condition?

Answer 15

• Occurs when multiple processes or threads read and write data items
• The final result depends on the order of execution

Question 16

When do u need Mutual exclusion in terms of software?

Answer 16

Software Approaches:
 Implemented for concurrent processes
 Execute on a single-processor or a multiprocessor machine
 Shared main memory

Question 17

What is Cooperation Among Processes by
Sharing?
UNIFINISHED

Answer 17

Covers processes that interact with other processes

without being explicitly aware of them

Question 18

What is Cooperation Among Processes by Communication?

UNFINISHED

Answer 18

The various processes participate in a common effort that links all of the processes

The communication provides a way to synchronize, or coordinate, the various activities

Question 19

What are 2 Requirements for Mutual Exclusion?

Answer 19

• Mutual exclusion must be enforced: only one process at a time is allowed into its critical section, among all processes that have critical sections for the same resource or shared object
• A process that halts must do so without interfering with other processes