Write a note on the usage of semaphores, Operating System

Assignment Help:

Write a note on the usage of semaphores.

Semaphore is a synchronization tool and it is a variable having integer values. It is accessed only by two standard atomic operations wait and signal. These operation were initially termed p(for wait) and v(for signal).

                The traditional definition for wait in pseudocode is:

 

                             wait(s)  {

                                         while(s<=0)

                                           ;//no-op

                                         s--;

                                          }

             The traditional definition for signal in pseudo code is:

 

                            signal(s) {

                                             s++;

                                           }

Alteration to the integer value of the semaphore in the wait and signal operations should be executed indivisibly. i.e., when one process alters the semaphore value .No other process is able to simultaneously modify that same semaphore value. Additionally in the case of wait(s) the testing of the integer value of s (s<=0) and its possible modification (s--) must as well be executed without interruption.


Related Discussions:- Write a note on the usage of semaphores

Synchronization, As we already know, threadsmust ensure consistency; otherw...

As we already know, threadsmust ensure consistency; otherwise, race conditions (non-deterministic results) might happen. Now consider the "too much milk problem": two people share

Basic synchronization, (Add synchronization to your solutions to HW 3 to el...

(Add synchronization to your solutions to HW 3 to eliminate all of the race conditions.  You should not remove any of the sleep() commands that you used to produce the race conditi

Explain types of file allocation-contiguous allocation, Contiguous allocati...

Contiguous allocation: Every file will be allocated contiguous space in the memory. Allow the block size be 1K If a 50K files desires to be allocated space after t

What is paging? name the different paging techniques, What is paging? Name ...

What is paging? Name the different paging techniques. Paging is a memory management method that permits the physical-address space of a process to be noncontiguous. Paging evad

Estimation the number of input - output per second, Q. Remapping of bad bl...

Q. Remapping of bad blocks by sector sparing or else sector slipping could influence performance. Presume that the drive in Subsequent Exercise has a total of 100 bad sectors at r

Explain multiprocessing operating system, Multiprocessing - An Operating S...

Multiprocessing - An Operating System proficient of utilizing and supporting more than one computer processor. Below are some instances of multiprocessing Operating Systems. Li

File system versus swap space, Q. What are the tradeoffs concerned in rerea...

Q. What are the tradeoffs concerned in rereading code pages from the file system versus using swap space to store them? Answer: If codes pages are accumulate in swap space th

What the different paging techniques, The different paging techniques are ...

The different paging techniques are 1. Multilevel paging or hierarchical paging method: In definite cases the page table may consist up to 1 million entries. This would be

Define drawback of distributed systems, Define drawback of Distributed syst...

Define drawback of Distributed systems Reliability is a drawback of Distributed systems

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