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

Producer – consumer process, Step by step displays the content, and the fin...

Step by step displays the content, and the final result of the list ("buffer") of 6 elements as the initial values ??and the following elements which are produced (NEXTP) or consum

Describe the buddy system of memory allocation, Buddy system of memory allo...

Buddy system of memory allocation Free memory is used to maintain in linked lists, each of similar sized blocks. Every block is of size 2^k. When some memory is needed by a th

Distinguish among pcs and scs scheduling, Q. Distinguish among PCS and SCS ...

Q. Distinguish among PCS and SCS scheduling. Answer: PCS scheduling is completed local to the process. It is how a thread library schedules threads onto available LWPs. SCS sch

Define loader that executed when system is first turned on, Define a loader...

Define a loader that is executed when a system is first turned on or restarted? Bootstrap loader is executed when a system is first turned on or restarted

Semaphore, mention the three problems that mat be caused by wrong initializ...

mention the three problems that mat be caused by wrong initialization and placement of wait() and signal()operations in the use of semaphore

List sample file types, List sample file types, based on use, on the VAX un...

List sample file types, based on use, on the VAX under VMS.  source programs (.BAS, .FOR, .COB, .PLI, .PAS, .MAR)  data files (.DAT)  text files (.TXT)  command proced

What is the occupation of the object manager, Q. What is the occupation of ...

Q. What is the occupation of the object manager? Answer: Substance present a generic set of kernel mode interfaces to user mode programs. Objects are influenced by the execut

Compute minimum transfer size for acceptable utilization, Q. It is occasio...

Q. It is occasionally said that tape is a sequential-access medium whereas magnetic disk is a random-access medium. In fact the correctness of a storage device for random access d

What are the characteristics of srs, What are the characteristics of SRS? ...

What are the characteristics of SRS? i. Correct - The SRS should be made up to date when appropriate requirements are identified. ii. Unambiguous - When the requirements are

Bounded and unbounded buffer, Ask question #Minimum 100 difference between ...

Ask question #Minimum 100 difference between bounded and unbounded buffer words accepted#

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