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

What are the advantages of multi threading?, What are the advantages of mul...

What are the advantages of multi threading?  Multithreading a code can have several advantages. Improve application responsiveness --Any program in which var

Perl script, Write a Perl script assignGrades.pl to assign letter grades to...

Write a Perl script assignGrades.pl to assign letter grades to the students.

Define the conditions of deadlock prevention, What are the four necessary c...

What are the four necessary conditions of deadlock prevention?       Ans:  Four essential conditions for deadlock prevention: a. The meaning of removing the mutual exclusio

Define page fault, Page fault is a trap to the software gained by the har...

Page fault is a trap to the software gained by the hardware when a process accesses a page that is goes in the virtual address space, but not added in physical memory. In the har

Can we call trap as an interrupt??, is there any difference between the tra...

is there any difference between the trap and interrupt??

Explain fixed partitioning techniques, FIXED PARTITIONING In a fixed p...

FIXED PARTITIONING In a fixed partitioning, the operating system inhabiting some fixed portion of main memory is available for use of multiple processes -Using fixed partit

Linux operation system, wat are the commands used for creating the file hie...

wat are the commands used for creating the file hierarchy

Multi-level page tables, Multi-level page tables are tree-like structures t...

Multi-level page tables are tree-like structures to hold page tables. As an example, consider a two- level page table, again on a 32-bit architecture with 212 = 4 kbyte pages. Now,

Explain file allocation using i nodes, File allocation using I nodes. T...

File allocation using I nodes. This method is used to decrease the size of the table in the above method. Every file will have an I-node list. Allow a file have 15 pointers a

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