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

Electronic typewriter , Electronic typewriter : An electronic typewriter h...

Electronic typewriter : An electronic typewriter has a 'memory' or 'electronic brain' which enables it to recall the whole document at a time and type it automatically at the pres

Define dma controller, Define DMA controller. The I/O device interface ...

Define DMA controller. The I/O device interface control circuit that is used for direct memory access is called as DMA controller.

Explain extended binary coded decimal interchange code, Q. Explain Extended...

Q. Explain Extended Binary Coded Decimal Interchange Code? Extended Binary Coded Decimal Interchange Code (EBCDIC) is a character-encoding format employed by IBM mainframes. It

Explain the synchronous-transmission, A control character is sent at the be...

A control character is sent at the beginning as well as at the end of every block in the synchronous-transmission in order to  (A) Synchronize the clock of transmitter and rece

How are interrupt handled by the operating system, How are interrupt hand...

How are interrupt handled by the operating system? The fundamental interrupt mechanism works as follows: The CPU hardware has wire called the interrupt-request line which

Infix to reverse polish, A) Change the following formulas from reverse Poli...

A) Change the following formulas from reverse Polish to infix:             a) AB +C + D x               b) ABCDE + x x / B) Change the following formulas from infix to

Human–computer interaction, In the view of the M364 module team, HCI has be...

In the view of the M364 module team, HCI has been superseded by ID. This is because HCI traditionally concentrated upon desktop computers with single users, whereas ID includes the

Device drivers in ms-dos, In MS-DOS device drivers are installed and loaded...

In MS-DOS device drivers are installed and loaded dynamically it implies that they are loaded into memory when computer is started or re-booted and accessed by operating system as

Struct and class, https://dl.dropbox.com/u/41918180/Images/Pro%202/2.png ...

https://dl.dropbox.com/u/41918180/Images/Pro%202/2.png https://dl.dropbox.com/u/41918180/Images/Pro%202/3.png https://dl.dropbox.com/u/41918180/Images/Pro%202/4.png">https://dl.d

Explain high level data link control, Explain High Level Data Link Control....

Explain High Level Data Link Control. HDLC - it is High Level Data Link Control: Protocol Overall explanation: Layer 2 of the OSI model is the data link layer. One of the

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