What do you mean by semaphore?, Operating System

Assignment Help:

What do you mean by semaphore? 

Semaphore: A synchronization variable that acquires on positive integer values. Invented by the Dijkstra

  • P (semaphore): an atomic process that waits for semaphore to turn into positive then decrements it by 1.
  • V (semaphore): It is an atomic process that increments semaphore by 1.

The names arrive from the Dutch, verhogen (increment) and proberen (test). Semaphores are elegant and easy and permit the solution of many interesting problems. They do many more than just mutual exclusion.

 


Related Discussions:- What do you mean by semaphore?

Sharing memory, As we have discussed, page tables map virtual page addresse...

As we have discussed, page tables map virtual page addresses to physical page addresses. One of the advantages of using virtual addresses is that we can achieve complete separation

Relationship among the capabilities of domain level j and i, Q. In a ring-...

Q. In a ring-protection system the level 0 has the greatest access to objects and level n (greater than zero) has fewer access rights. The access rights of a program at a partic

What are the objectives for a file management system, What are the objectiv...

What are the objectives for a file management system? To meet the data management wants and requirements of the user, which embrace storage of data and the ability to

Explain kernel-level threads (klt), KERNEL-LEVEL THREADS (KLT) In this...

KERNEL-LEVEL THREADS (KLT) In this level every thread management is done by kernel .No thread library except an API system calls to the kernel thread facility exists. The kern

Rule a magnetic hard disk, Q. If magnetic hard disks eventually have the s...

Q. If magnetic hard disks eventually have the same cost per gigabyte as do tapes will tapes turn into obsolete or will they still be needed? Describe your answer. Answer: Tap

Explain the various file types, Explain the various file types A common...

Explain the various file types A common technique for executing file types is to contain the type as part of the file name. The name is split into two parts - a name and an ext

Write a brief note on demand paging, Write a brief note on demand paging. ...

Write a brief note on demand paging. A demand paging is alike to a paging system with swapping. The Processes reside on the secondary memory while we want to implement a proces

What are two probable uses of these multiple modes, Q. Several CPUs provide...

Q. Several CPUs provide for more than two modes of operation. What are two probable uses of these multiple modes? Answer: Although most systems merely distinguish between use

Explain segmentation hardware?, Explain segmentation hardware? We defin...

Explain segmentation hardware? We define an completion to map two-dimensional user-defined addresses into one-dimensional physical addresses. This mapping is affected by means

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