Write a note on the usage of semaphores, Operating System

Assignment Help:

Write a note on the usage of semaphores.

Semaphore is a synchronization tool and it is a variable having integer values. It is accessed only by two standard atomic operations wait and signal. These operation were initially termed p(for wait) and v(for signal).

                The traditional definition for wait in pseudocode is:

 

                             wait(s)  {

                                         while(s<=0)

                                           ;//no-op

                                         s--;

                                          }

             The traditional definition for signal in pseudo code is:

 

                            signal(s) {

                                             s++;

                                           }

Alteration to the integer value of the semaphore in the wait and signal operations should be executed indivisibly. i.e., when one process alters the semaphore value .No other process is able to simultaneously modify that same semaphore value. Additionally in the case of wait(s) the testing of the integer value of s (s<=0) and its possible modification (s--) must as well be executed without interruption.


Related Discussions:- Write a note on the usage of semaphores

Performance of job scheduling strategies, Performance of Job Scheduling  St...

Performance of Job Scheduling  Strategies In this project you will investigate the performance of Job Scheduling strategies, Memory Allocation strategies and a CPU Scheduling s

Explain the request/response interface, Explain the Request/Response Interf...

Explain the Request/Response Interface   Many issues are involved in providing a procedural interface for client functions to interact with server components. First off, since

Paging, Paging full question

Paging full question

Explanation of modern cpu architectures, Your CTO liked your proposal from ...

Your CTO liked your proposal from Unit 2 so much he only trusts you to explain complex concepts to his managers. He now wants you to write him a four page paper explaining the CPU,

Write a note on threads, Question 1 Explain (a) tightly coupled systems   ...

Question 1 Explain (a) tightly coupled systems                               (b) Loosely coupled system Question 2 Describe the RPC model Question 3 Write a note o

What is preallocation, What is preallocation? Why do it? Allocating spa...

What is preallocation? Why do it? Allocating space for a file before making the file to allow for expansion. This reserves space for a certain file so that other files can't gr

Explain about interprocess communication, Explain about interprocess commun...

Explain about interprocess communication The cooperating processes communicate with each other via an interprocess communication facility. IPC gives a mechanism to permit proce

Permanently starves cpu-bound programs, Q. Presume that a scheduling algori...

Q. Presume that a scheduling algorithm at the level of short-term CPU scheduling favours those processes that have used the least processor time in the recent past. Why this algori

Explain the tlsgetvalue (tlsindex) function, Explain the TlsGetValue (TLSin...

Explain the TlsGetValue (TLSindex) Function Executing this function will return the thread local storage data associated with this thread. The pointer returned will be the one

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