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 the use of urgent pointer in tcp segment, What is the use of urgent...

What is the use of urgent pointer in TCP segment? For accommodation out of band signaling, TCP permits the sender to identify data as urgent, implies that the receiving program

Software Engineering, Software Engineering is a layered technology. Explain...

Software Engineering is a layered technology. Explain

High level expertise, The most useful feature of an expert system is the h...

The most useful feature of an expert system is the high level expertise it provides to aid in problem solving. This expertise can represent the best thinking of the top

What is meant by a field, What is meant by a field The consecutive nonw...

What is meant by a field The consecutive nonwhite space characters that define a data item collectively define a field. It is possible  to limit the number of such characters b

Explain about flip-flops, Explain about Flip-Flops  Flip-Flops are also...

Explain about Flip-Flops  Flip-Flops are also called bistable multivibrator.  A flip-flop is capable of storing 1 bit of binary data.  It has two stable states- 'one' and 'zero

Explain passing parameters in general memory, Q. Explain Passing Parameters...

Q. Explain Passing Parameters in General Memory? The parameters can be passed in the memory too. In such a technique name of the memory location is used as a parameter. The res

What is pure semiconductors, Q. What is Pure semiconductors? Pure semic...

Q. What is Pure semiconductors? Pure semiconductors, known as intrinsic semiconductors, have very few charge carriers and may hence be classified as almost insulators or very p

Explain direct or indirect communication, Explain Direct or Indirect Comm...

Explain Direct or Indirect Communication in Inter-process communication. Several types of message passing system in Direct or Indirect Communication are given below:

Determine the hardware for multiplication, Determine the hardware for multi...

Determine the hardware for multiplication The hardware for multiplication consists of equipment given in Figure. The multiplier is stored in register and its sign in Q . The se

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