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?

Describe what is meant by client-server computing, Question 1: (a) Desc...

Question 1: (a) Describe what is meant by Client-server Computing? (b) Distinguish between a server process and a client process. (c) What are the basic characteristics o

Page faults, Assume there are only 4 page frames in the physical memory, fo...

Assume there are only 4 page frames in the physical memory, for the following reference string: 1, 2, 3, 4, 5, 3, 4, 1, 6, 7, 8, 7, 8, 9, 7, 8, 9, 5, 4, 5, 4, 2, 8. a) What i

Write an equation for this seek time, Q. The accelerating search for descr...

Q. The accelerating search for described in subsequent exercise is typical of hard-disk drives. By contrast floppy disks and several hard disks manufactured before the mid-1980s t

How many page faults take place in lru replacement, Q. Consider the subseq...

Q. Consider the subsequent page reference string: 1, 2, 3, 4, 2, 1, 5, 6, 2, 1, 2, 3, 7, 6, 3, 2, 1, 2, 3, 6. How many page faults would take place for the following replace

Main advantages of the microkernel approach to system design, What are the ...

What are the main advantages of the microkernel approach to system design? Benefits typically contain the following  (a) Adding a new service does not require modifying the

Find the parent process and the child process, Q. When a process creates a...

Q. When a process creates a fresh process using the fork() operation which of the following state is shared among the parent process and the child process? 1 Stack 2 Heap

Explain why sstf scheduling tends to favor middle cylinders, Explain why SS...

Explain why SSTF scheduling tends to favor middle cylinders over the innermost and outermost cylinders. The center of the disk is the location having the fewest average distanc

Microsoft, Discuss the high barriers to entry in the market for PL operatin...

Discuss the high barriers to entry in the market for PL operating systems

Explain briefly the working of semaphore with example ?, Explain briefly th...

Explain briefly the working of semaphore with example ? The E.W. Dijkstra (1965) abstracted the key idea of mutual exclusion in his concepts of semaphores. Definition A s

Reference counting, The idea of reference counting is to maintain, for ever...

The idea of reference counting is to maintain, for every object, the total number of references to that object, i.e. the number of "incoming" pointers. Whenever the number of refer

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