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

Compute total and access methods, Write a program that input (from the user...

Write a program that input (from the user) the number of hours worked and hours pay rate for employees and output their total pay. The program should process an arbitrary number of

Flynn’s classification, Flynn's Classification Flynn's classification i...

Flynn's Classification Flynn's classification is based on multiplicity of data streams and instruction streams observed by the CPU during program execution. Let Ds and Is  are

Flowchart, How to calculate the flowchart

How to calculate the flowchart

Leading zeroes of a number field, In order to suppress the leading zeroes o...

In order to suppress the leading zeroes of a number field the which keywords is used ? NO-ZERO.

Find the shortest path, The following is the required interface for the mou...

The following is the required interface for the mouse and cheese problem. Your program is required to read its input from a file named 'maze.txt' In the maze.txt

What are the special features of direct rdram, What are the special feature...

What are the special features of Direct RDRAM? It is a two channel Rambus It has 18 data lines intended to transfer two bytes of data at a time There are no divide

Produce an analysis model of the proposed system, Question: Read the fo...

Question: Read the following case study and answer the questions based on it. The local airline company needs to develop a system for controlling air traffic at the airport

Compare single bus structure and multiple bus structure, Compare single bus...

Compare single bus structure and multiple bus structure? A system that having only one bus(i.e only one transfer at a time) is known as a single bus structure. A system is know

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