Explain banker''s algorithm, Operating System

Assignment Help:

Banker's Algorithm

In this analogy

Customers

processes

Units

resources, say, tape drive

Banker

Operating System

 

Customers

Used

Max

 

A
B
C
D

0
0
0
0

6
5
4
7

Available Units = 10

 

 

 

 

 

 

 

 


We observe four customers each of whom has been granted a number of credit nits. The banker reserved only 10 units somewhat than 22 units to service them. At definite moment the situation becomes

Customers

Used

Max

 

A
B
C
D

1
1
2
4

6
5
4
7

Available Units = 2

 

 

 

 

 

 

 

 

Safe State-    The key to a state being secure is that there is at least one way for all users to finish. In other analogy the state of is safe because with 2 units left, the banker is able to delay any request except C's, therefore letting C finish and release all four resources. With four units in hand the banker is able to let either D or B have the necessary units and so on.

Unsafe State-     Consider what would take place if a request from B for one more unit were granted

We would have following situation

Customers

Used

Max

 

A
B
C
D

1
2
2
4

6
5
4
7

Available Units = 1

 

 

 

 

 

Fig. 3

 

 

This is an unsafe state.

If all the customers namely A, B, C, and D request for their maximum loans, then banker couldn't satisfy any of them and we would have a deadlock.

It is significant to note that an unsafe state does not imply the existence or even the eventual existence a deadlock. What an unsafe state does involve is simply that some unfortunate sequence of events might lead to a deadlock. The Banker's algorithm is therefore to consider each request as it occurs and see if granting it leads to a safe state. If it does, the request is granted or else, it postponed until later.


Related Discussions:- Explain banker''s algorithm

State critical section problem, State critical section problem? Discuss thr...

State critical section problem? Discuss three solutions to solve the critical section problem. C-S Problem:- n processes all competing to use some shared data Every

Information system can be divided into three task areas, From hardware pers...

From hardware perspective, every information system can be divided into three task areas Presentation, Application Logic and Data Storage. The R/3 Basis software is extremely s

define system calls, When a computer is started on, the program that execu...

When a computer is started on, the program that executed first is named the ''operating system.'' It controls pretty much all applications in the computer. This adds who logs in, h

Explain the various methods of file access, Operating Systems 1. Illust...

Operating Systems 1. Illustrate the Microkernel Architecture with suitable diagram. 2. When Deadlock occurs? What are the Necessary Conditions for Deadlock? 3. Describe f

Explai basic concepts of demand paging, Basic concepts When a process i...

Basic concepts When a process is to be changed in, the pager guesses which pages will be used before the process is changed out again. Instead of swapping in a entire process,

What is the basic approach of page replacement, What is the basic approach ...

What is the basic approach of page replacement? If no frame is free is available, find one that is not presently being used and free it. A frame can be freed by writing its con

Explain process scheduling, Explain Process scheduling Process scheduli...

Explain Process scheduling Process scheduling consists of the subsequent sub-functions: 1.      Scheduling : Selects the process to be implement next on the CPU 2.      D

What do you understand by active directory domain, Question: a) What ...

Question: a) What do you understand by Active directory domain in Windows Server 2008? Support your answer with a diagram. b) Distinguish between active directory trees

Explain file control list and user control list, Q. Researchers have recom...

Q. Researchers have recommended that instead of having an access list associated with each file (specifying which users can access the file and how) we should have a user control

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd