Applications of Semaphore: An Overview

An Operating System (OS) is an interface between computer user and computer hardware. It is software which performs all the basic tasks like file management, memory management, process management, handling input and output, and controlling peripheral devices such as disk drives and printers. Operating System primarily provides services for running applications on a computer system. The primary need for the OS arises from the fact that user needs to be provided with services and OS ought to facilitate the provisioning of these services. The central part of a computer system is a processing engine called CPU. A system should make it possible for a user’s application to use the processing unit. A user application would need to store information. The OS makes memory available to an application when required. Similarly, user applications need use of input facility to communicate with the application. In this paper we have discussed about execution of concurrent programming problems and increasing the reliability and efficiency of this programs using synchronization primitive tool called the semaphore with various applications. It is an integer valued variable which can take only non- negative values. It uses two operators called Wait(s) and Signal(s).Wait(s) If S>0 then S:=S-1 Else suspend the execution. Signal(S) If there are processes that have been suspended on this semaphore wake one of them else S:=S+1.