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

Explain the propagation delay characteristics for digital ic, Explain the ...

Explain the Propagation Delay characteristics for digital IC's. Ans: Propagation Delay: - The speed of a digital IC operation is given in terms of propagation delay ti

Micro-programmed control, Q. MICRO-PROGRAMMED CONTROL? A substitute to ...

Q. MICRO-PROGRAMMED CONTROL? A substitute to a hardwired control unit is a micro-programmed control unit in which logic of the control unit is specified by a micro-program. A m

Advantage of doubly linked list over singly linked list, What is the advant...

What is the advantage of doubly linked list over singly linked list?       Ans: Benefits of the doubly linked list over singly linked list 1. A doubly linked list can be pas

Show the internet protocols, A communication protocol is an agreement which...

A communication protocol is an agreement which specifies a common language two computers use to exchange messages. For instance, a protocol specifies exact format and meaning of ev

What are disadvantages of eprom, What are disadvantages of EPROM? The c...

What are disadvantages of EPROM? The chip must be physically removed from the circuit for reprogramming and its whole contents are erased by the UV light.

Basic performance equation, Explain the basic performance equation Ans...

Explain the basic performance equation Ans: The basic performance equation is following T = N * S/ R T =>  It is processor time required to execute a program N => act

Define the full form of ssl, Define the full form of SSL SSL has becom...

Define the full form of SSL SSL has become fundamental to the spread of Internet community, and commerce and trade over Internet. Over years, the spread of its use for an incr

Explain about encoding technique used in bitmaps indexes, Bitmaps commonly ...

Bitmaps commonly use one bitmap for each single distinct value. Number of bitmaps used can be decreased by opting for a dissimilar type of encoding. Space can be optimized but when

Explain about 4-bit adder-subtractor circuit, Q. Explain about 4-bit adder-...

Q. Explain about 4-bit adder-subtractor circuit? Subtraction operation on binary numbers can be obtained by succession of addition operations only it implies that to achieve su

What is an xml entity, Problem : (a) Show whether or not a standard for...

Problem : (a) Show whether or not a standard format for representing data, such as XML, is needed. (b) Using an appropriate example, describe how data is organized in a dat

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