Explain peterson''s solution for the critical section problem, Operating System

Assignment Help:

Explain the Peterson's solution for the critical section problem?

In Peterson's solution two variables a) flag and b) turn are used as shared variables. If the both shared variables are set after that particular process can get into the critical section. Or else it gives other processes to get into the critical section and consider the segment for a process Pi to get into the critical section.

         do

            {

               flag[i]=true

               turn=j

               while(flag[j]&&turn==j)

               critical section

               flag[i]=false

               remainder section

            }while(1)

 

code segment for a process Pj is as follows:-

do

            {

               flag[j]=true

               turn=i

               while(flag[i]&&turn==i)

               critical section

               flag[j]=false

               remainder section

            }while(1)

 

            When flag[i]=true and turn=j is implemented, let a context switch take place. Therefore the control comes to the process Pj. therefore the statement flag[j]=true is executed. Again a contest switch take place and control is now with Pi. Therefore when the while condition is checked both of the conditions are true. Therefore while condition is true always and it ends up in an infinite loop. Therefore Pi is in an infinite loop and waits till the condition gets false. Therefore Pj executes here first and makes flag[j]=false. Therefore when a context switch occurs, Pi will get into its critical section. Implementation of each process depends on the context switch occurring between the two processes.


Related Discussions:- Explain peterson''s solution for the critical section problem

What are the different methods for handling deadlocks?, What are the differ...

What are the different methods for handling deadlocks? Deadlock detection and recovery: Permit the system to enter a deadlock state, detect it and after that rec

Computer organisation, basic advantage of using interrupt initiated data tr...

basic advantage of using interrupt initiated data transfer over transfer under program control without an interrupt

Mention some attractive properties of semaphore?, Mention some attractive p...

Mention some attractive properties of semaphore?              The Semaphores aren't provided by hardware. However they have numerous attractive properties: Machine indep

Assignment, You must use fork and pipe to complete this project. This proj...

You must use fork and pipe to complete this project. This project creates processes to add all numbers in a file. The user will enter a number (1, 2, or 4) of parallel processes

Define pure and impure interpreters, Pure and impure interpreters      ...

Pure and impure interpreters      In a pure interpreter, the source program is maintained in the source form throughout its interpretation. This arrangement acquires substantia

Identify main functions of an operating system, Question: Introduction to ...

Question: Introduction to Operating Systems a) Define the term ‘Operating System' and identify main functions of an operating system. b) What are the characteristics of a go

What are the advantages of contiguous allocation, What are the advantages o...

What are the advantages of Contiguous allocation? The advantages are a. Supports direct access b. Supports sequential access c. Number of disk seeks is minimal.

Determine scheduling policy for time-shared operating system, Determine a s...

Determine a scheduling policy that is most suitable for a time-shared operating system   Round-Robin is a scheduling policy that is most suitable for a time-shared operating s

What do you mean by first fit, What do you mean by first fit? First fit...

What do you mean by first fit? First fit allocates the first hole that is big sufficient .Searching can either start at the starting of the set of holes or where the previous f

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