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

Explain about diffrent process state, Q. Explain about diffrent Process Sta...

Q. Explain about diffrent Process State? Process State When process executes, it changes its state. Process state is defined as the current activity of the process. Fi

CPU, TURNAROUND TIME

TURNAROUND TIME

What are the advantages of using unequal- size partitions, In fixed portion...

In fixed portioning scheme, what are the advantages of using unequal- size partitions? With unequal-size partitions there are two probable ways to assign process to partitions.

List antivirus techniques used for protection purposes, Question: a) Th...

Question: a) There are main goals of data security. List them and elaborate on how they provide protection. b) Describe threats associated with data security. c) Describe

Comparing gc to malloc, Garbage collectors trade space for time. If we coll...

Garbage collectors trade space for time. If we collect all the time (which requires a lot of processing time), the GC allocator will use the least memory possible. On the other han

Major locking errors, When programming with threads, there are three very c...

When programming with threads, there are three very common mistakes that programmers often make: 1. locking twice (depending on the system and type of lock, can cause crashes, h

Advantage of minimizing the file space, Q. a number of systems automaticall...

Q. a number of systems automatically delete all user files when a user logs off or a job terminates unless the user explicitly requests that they be kept other systems keep all fil

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