What are semaphores, Computer Engineering

Assignment Help:

What are semaphores?

Semaphore: A semaphore is a synchronization tool which gives a general-purpose solution to controlling access to critical sections. It s an abstract data type (ADT) which defines a nonnegative integer variable that, apart from initialization, is accessed simply through two standard operations that are: wait and signal. The typical definition of wait in pseudo code is

wait(S){

          while(S<=0)

                 // do nothing

                          S--; }

The classical definitions of signal in pseudo code is signal(S){

                    S++; }

While one process modifies the semaphore value, anno one process can concurrently modify that similar semaphore value. As well, in the case of the wait(S), the testing of the integer value of S (i.e. S<=0), and its possible modification(S--), should also be executed without interruption.


Related Discussions:- What are semaphores

what is polymorphism in c++, Polymorphism in C++ is the idea that a base c...

Polymorphism in C++ is the idea that a base class can be inherited by various classes. A base class pointer can point to its child class and a base class array can store dissimilar

Explain isdn address structure and its working, Draw the ISDN address struc...

Draw the ISDN address structure and explain how the addressing works? Address Structure: The ISDN address structure is demonstrated in figure. ISDN number part has a maximum

Define cloud services with example, Define Cloud services with example. ...

Define Cloud services with example. Any web-based application or service offered by cloud computing is known as a cloud service. Cloud services can contain anything from calend

What is modem?, A device, usually linked to a serial port of a computer, th...

A device, usually linked to a serial port of a computer, that transfer data over regular phone lines. Modem stands modulator demodulator; it changes a digital stream of data into s

Explain the random scan and raster scan displays, Define Random scan/Raste...

Define Random scan/Raster scan displays?  Random scan is a method in which the display is made by the electronic beam which is directed only to the points or part of the screen

Fuzzy logic - artificial intelligence, Fuzzy Logic: In the logics we a...

Fuzzy Logic: In the logics we are here described above, what we have been concerned with truth: whether propositions and sentences are true. Moreover, with some natural langua

Define top-down parsing techniques, Define Top-down parsing Techniques ...

Define Top-down parsing Techniques Top-down parsing can be observed as an attempt to find left-most derivations of an input-stream through searching for parse trees using a top

Porcess of identifying input and output values, Porcess of Identifying Inpu...

Porcess of Identifying Input and Output Values First, recognize what data is going to be used as input to system, and what will be output from system. Input and output values

Voice identifier - biometric computer security systems, Voice Identifier - ...

Voice Identifier - Biometric Computer Security Systems Besides fingerprint, another popular security technology is voice identifier. According to VSS organization (2007), voic

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