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

What are batch systems, What are batch systems? Batch systems are quite...

What are batch systems? Batch systems are quite appropriate for implementing large jobs that need little interaction. The user can submit jobs and return later for the results.

Define where a program generation activity aims, Define where a Program gen...

Define where a Program generation activity aims  Program generation activity aims at Automatic generation of program

Network operating system and a distributed operating system, Problem: (...

Problem: (a) (i) Explain what a single system image is and how it is related to the concept of a distributed operating system? (ii) What are the main differences between a

Define maintaining data on a per client basis, Define Maintaining Data on a...

Define Maintaining Data on a Per Client Basis Perhaps the most dramatic syntactical programming change for the application developer of client – server applications is maintain

Explain lru additional reference bits algorithm, Additional Reference bits...

Additional Reference bits algorithm Here we keep an 8-bit byte for every page in memory. At standard intervals the reference bit is shifted by the OS. If a shift register conta

Research proposal, what topic i choose for os research proposal

what topic i choose for os research proposal

Aggregate planning, Prepare a report that motivates alternatives reactive s...

Prepare a report that motivates alternatives reactive strategies that can be used by wind Mud clothing factory

Describe what is meant by client-server computing, Question 1: (a) Desc...

Question 1: (a) Describe what is meant by Client-server Computing? (b) Distinguish between a server process and a client process. (c) What are the basic characteristics o

What is a file, What is a file? A file is a named collection of related...

What is a file? A file is a named collection of related information that is recorded on secondary storage. A file having either programs or data. A file has particular "structu

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