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

Shell scripting, A friend has promised to log in at a particular time. Howe...

A friend has promised to log in at a particular time. However, he needs to be contacted as soon as he logs in. The shell script checks after every minute whether he has logged in o

Define deadlock, Define deadlock. A process requests resources; if the ...

Define deadlock. A process requests resources; if the resources are not available at that time, the process enters a wait state. Waiting processes might be never again change s

Merits of device controller in the kernel, Q. State three merits of placing...

Q. State three merits of placing functionality in a device controller rather than in the kernel and State three disadvantages. Answer: Three advantages: Bugs are less probabl

Process abstraction in operating systems, Many early operating systems rega...

Many early operating systems regarded processes as different timesharing users. The process abstraction is a popular way to organize concurrent programs, but it is not the only cho

Define unixware, Define UnixWare UnixWare manages resources at the proc...

Define UnixWare UnixWare manages resources at the process level. Each resource allocated to the application is actually allocated to the process representing the application. C

All the explanations of operating system and its types., operating systems ...

operating systems and its types together with its design issues and their examples.

Multiprogramming., In a multiprogramming and time sharing environment sever...

In a multiprogramming and time sharing environment several users share the system simultaneously .what are two such problems?

What is a buddy system?, What is a buddy system? We are dividing the me...

What is a buddy system? We are dividing the memory as powers of two therefore the division will be 2, 4, 8, 16, 32, 64, 128, 256...i.e. in powers of 2 as well as we are selecti

Calculate the maximum file size , A UNIX file system has 1-KB blocks and 4-...

A UNIX file system has 1-KB blocks and 4-byte disk addresses. What is the maximum file size if i-nodes contains 10 direct entries, and one single, double, and triple indirect entry

Computer, what is an operating system?

what is an operating system?

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