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

Cosled loop, What are the two principles in Hungarian method?

What are the two principles in Hungarian method?

Explain process state with diagram, Question 1 Explain single Partition Al...

Question 1 Explain single Partition Allocation and Multiple Partition Question 2 What is PCB? What useful information is available in PCB? Question 3 Explain Preemptive and No

Linux, Discuss the risks of having a single root user

Discuss the risks of having a single root user

Virtualization, What factors are involved in choosing the host operating sy...

What factors are involved in choosing the host operating system?

What problems arise if the directory is a general graph, What problems aris...

What problems arise if the directory structure is a general graph? Searching for a particular file may result in searching the similar directory many times. Deletion of the fil

What is an i/o subsystem, What is an I/O subsystem? The control of devi...

What is an I/O subsystem? The control of devices connected to the computer is a main issue while designing operating systems. Because I/O deices differ widely in their function

What is the sequence of a page fault causes to occur, A page fault causes t...

A page fault causes the following sequence to occur. 1. Trap (shut in) to the operating system. 2. Save the process registers and process state. 3. Verify that the interr

Embedded systems design or hardware design, You have been requested by your...

You have been requested by your Senior Engineer to design an Engine Control Unit (ECU) and prepare a report detailing your proposed solution. The client requires a design for a mic

define system calls, When a computer is started on, the program that execu...

When a computer is started on, the program that executed first is named the ''operating system.'' It controls pretty much all applications in the computer. This adds who logs in, h

Command interpreters, Develop a user mode command interpreter which support...

Develop a user mode command interpreter which support these functions: "list-short" -- just like ls without any options "list-long" -- same as ls -l "change" -- same as cd Your co

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