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

Define the dossleep(ms) function used in the os/2, Define the DosSleep(ms) ...

Define the DosSleep(ms) Function used in the os/2 DosSleep()  suspends the currently executing  thread for some time interval specified in the  ms parameter. If a value of 0 is

Describe the differences among short-term and medium-term, Describe the dif...

Describe the differences among short-term, medium-term, and long-term scheduling.   Short-term (CPU scheduler)-selects from jobs in memory those jobs that are ready to execu

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

Explain about system software, An operating system act as an intermediary b...

An operating system act as an intermediary between user of a computer and computer hardware. The objective of an operating system is to provide an environment in that a user can ex

Garbage collection, The dynamic memory allocator is a layer between the app...

The dynamic memory allocator is a layer between the application and the OS, managing heap objects. When a program requests memory from the allocator (via malloc(), for instance), t

Explain the real time operating system, Explain the Real Time Operating Sys...

Explain the Real Time Operating System A real-time operating system comprises definite, fixed time constraints. Processing should be done in the defined constraints, or the sys

Implementation of modern memory management system , Central to implementati...

Central to implementation of a modern memory management system is the page replacement algorithm. Modern virtual memory systems break memory up into pages and map (via a page table

Explain about deadlock prevention, Explain about deadlock prevention? I...

Explain about deadlock prevention? In order for the occurrence of deadlock, the four conditions like mutual exclusion, hold and wait, no pre-emption and  circular wait must hap

Write knowledge base relevant propositional statement, Suppose a logic-base...

Suppose a logic-based agent in the wumpus world has found that locations (1,1) and (2,1) do not contain a stench, but that locations (3,1) and (2,2) do contain a stench. Can the ag

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