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

Time complexity in the worst case, Speicified the following piece of code: ...

Speicified the following piece of code: int i = 1; int j = 4; while (i     {      if (i%3 == 0) i+=3;      else i+=4;        if (j%2 == 0) j*=4;      els

What are the elements of an instruction, Q. What are the elements of an ins...

Q. What are the elements of an instruction? As the function of instruction is to communicate to CPU what to do it needs a minimum set of communication such as:  What op

PADOVAN STRING, write a program that counts the number of occurrences of th...

write a program that counts the number of occurrences of the string in the n-th Padovan string P(n)

Describe the concepts of information systems delivery cycle, Write a 2-3 pa...

Write a 2-3 page paper (excluding title, abstract, introduction, and references) describing the concepts of the Information Systems Delivery Cycle (SDLC) and how the Project Manage

CRTscreen as a two-dimensional matrix, Explain the statement- CRT screen as...

Explain the statement- CRT screen as a two-dimensional matrix One can imagine the CRT screen as a two-dimensional matrix which has m rows and n  columns and this is usually ref

Problem solving in parallel-, Problem Solving In Parallel Introduction ...

Problem Solving In Parallel Introduction to Parallel Computing This section examines how a particular task can be broken into minor subtasks and how subtasks can be answer i

Difference between the testing and verification, Difference between the tes...

Difference between the testing and verification. Verification proves conformance with a specification. Testing tries to find cases where the system does not meet its specifi

Purpose of pointer phrase in string command, The Purpose of POINTER phrase ...

The Purpose of POINTER phrase is to verify the leftmost position within receiving field where the first transferred character will be kept

What is page fault, What is page fault? Its types? Page fault refers to...

What is page fault? Its types? Page fault refers to the situation of not having a page in the major memory when any process references it. There are two kinds of page fault :

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