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

Advantages of e-commerce, One of the resources we used was Ajeet Khurana's ...

One of the resources we used was Ajeet Khurana's article that talks about the advantages of e-commerce. It was helpful to gain some background on the variety of benefits the electr

Describe the errors, Q. Describe the Errors? Errors  Two probable...

Q. Describe the Errors? Errors  Two probabletypes of errors may take place in assembly programs:   a. Programming errors: They are familiar errors you may encounter in

How does bus arbitration typically work, How does bus arbitration typically...

How does bus arbitration typically work? i.  A bus master waiting to use the bus asserts by  the bus request. ii.  A bus master cannot be the bus until it's request is grant

What kind of system do we need to run gimp, Any system able of run Gnome 2,...

Any system able of run Gnome 2, KDE 3.2, Windows 2000, Mac OS X and later versions should be capable to run GIMP. GIMP's biggest appetite is for memory and how much you will requir

Why a function should have at least one input, Why a function should have a...

Why a function should have at least one input? There is no strong reason for this in verilog. I think this restriction isn't removed fin SystemVerilog. Some requirements where

Explain efficiency performance and issues in pipelining, Efficiency The...

Efficiency The effectiveness of pipeline can be measured the same as the ratio of busy time span to total time span counting the idle time. Let c be clock period of a pipeline

Standards used for development of a system, Q. Standards used for developme...

Q. Standards used for development of a system? Documentation standards: It must be an ongoing activity at the time of system development life cycle.  Quality Standards:

Explain the terms constructors and destructors, When we initialize the form...

When we initialize the form at that time if we require to set any variable's value then we can set it by defining in constructor. Constructor's name always similar as class name an

Convert binary number in two''s compliment form, Convert binary number in t...

Convert binary number in two's compliment form 0100 1000. Converting the binary number into 2's compliment from 0100 1000 is given below: 01001000 => 10111000

Give some technical specification for subscriber lines, Give some technical...

Give some technical specification for subscriber lines. Subscriber pairs and exchange pairs are interconnected at the MDF through jumpers. The MDF therefore gives a flexible in

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