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

Replacement algorithm for tlb, Consider the following C program where M, N,...

Consider the following C program where M, N, K are predefined constants. Assume int is 4 bytes. Suppose this program is run on a machine with 4KB page size and 32 TLB entries. Init

Define local procedure call, Q. What kinds of services does the process man...

Q. What kinds of services does the process manager provide? Define local procedure call? Answer: The process manager offers services for creating and deleting and using proce

Necessary conditions for deadlock, Here are the conditions necessary for a ...

Here are the conditions necessary for a deadlock to occur; note that all of them are necessary, and none is suf?cient: 1. ?nite resources: the resources are held in a mutually-e

Main advantages of the microkernel approach to system design, What are the ...

What are the main advantages of the microkernel approach to system design? Benefits typically contain the following  (a) Adding a new service does not require modifying the

Drawbacks of least-recently used algorithm, The question of fairness, regar...

The question of fairness, regarding page eviction, is a hard one. How do we decide what is fair? Many operating systems use global LRU, where pages from all processes are managed t

Designing issues in a network -transparency, Transparency Users mus...

Transparency Users must be able to access remote resources as though these resources were local. Transparency should as well promote user mobility. Users must be allowed

Elimination of common sub expression - code optimizatin, Elimination of com...

Elimination of common sub expression during code optimization An optimizing transformation is a rule for rewriting a section of a program to enhance its execution efficiency wi

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