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

Linux, what is I/O management Linux

what is I/O management Linux

Is disk scheduling useful in a single-user environment, Is disk scheduling,...

Is disk scheduling, other than FCFS scheduling, useful in a single-user environment? Explain your answer. In a single-user environment, the I/O queue usually is blank. Requests

What are batch systems?, What are batch systems? Early computers were p...

What are batch systems? Early computers were physically huge machines run from a console. The general input devices were card readers and tape drivers. The common output device

Important system components, Organizational, Structural, Logical and Execut...

Organizational, Structural, Logical and Execution Relationships Between Important System Components in Linux Kernel Subsystems A. Description of the Project You are require

Explain kernel-level threads (klt), KERNEL-LEVEL THREADS (KLT) In this...

KERNEL-LEVEL THREADS (KLT) In this level every thread management is done by kernel .No thread library except an API system calls to the kernel thread facility exists. The kern

Explain the protection problems, Q. In some systems a subdirectory is able...

Q. In some systems a subdirectory is able to be read and written by an authorized user just as ordinary files can be. a. Explain the protection problems that could arise. b.

What are the objectives of operating system?, What are the objectives of op...

What are the objectives of operating system? Objectives of OS 1.      Convenience: An OS makes a computer more suitable to use. 2.      Efficiency : An OS allows t

Explain lru page replacement in detail, LRU page replacement In least ...

LRU page replacement In least lately used page replacement algorithm we will replace that page that hasn't been used for the longest period of time. This is similar as an opti

Explain about memory-management scheme, Q. In the IBM/370 memory protectio...

Q. In the IBM/370 memory protection is offered through the use of keys. A key is a 4-bit quantity every 2K block of memory has a key (the storage key) associated with it. The CPU

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