haamac.blogg.se - Optimal page replacement algorithm in java

Strng_size = Integer.parseInt(br. Entering the string size of the reference By utilizing optimal page-replacement algorithm ensure the most minimal conceivable page fault rate for a fixed number of frames. (" Enter the total number of Frames: ") įrames = Integer.parseInt(br.readLine()) According to Optimal Page Replacement algorithm, it is always optimal to replace the page which is going to be used least in the future. Int frames, pointer = 0, hit = 0, fault = 0,strng_size This algorithm says that if we know which page we are gonna use in future then we can optimize the page replacement technique. Public static void main(pagestring args) throws IOExceptionĬountbuffer bfr = new Countbuffer(new InputStreamReader(System.in)) creation of the main class to implement Optimal page replacement algorithm Replace page that will not be used for longest period of time. importing packages to use classes in the page replacement program Operating System Concepts with Java 8th Edition.

User Level thread Vs Kernel Level thread.Bounded Buffer Problem / Producer Consumer Problem.This is so because LRU is a stack algorithm. of page fault may decrease or remain same if no of frame is increased. Belady's anomaly states that increasing number of frames will never increase number of page faults if LRU page replacement algorithm is used. This phenomenon is an example of Belady's anomaly. That means no of page faults has decreased with the increase in frame number.

The outputs show that the no of page fault for 4 frames are 17 while the no of page fault for 5 frames are 16.

Replace the page having the least counter value with current page.Ĭ++ implementation of LRU page replacement algorithm and Belady's anomaly # include using namespace std int page_faults ( int page, int n, int frame_size ) Optimal Page Replacement algorithm this algorithms replaces the page which will not be referred for so long in future.

We basically need to replace the page with minimum counter. Whenever a page fault occurs, the page that is least recently used is removed from the memory frames.

Find the page in the set that was least recently used.

Simultaneously maintain the recent occurred counter (which has come most recently or least recently) of each page in a map called page_counter. Insert pages one by one until the size of page_set reaches frame_size or all page references are processed.

Page_set holds less pages than frame_size. In Least Recently Used page replacement algorithm (LRU) is associated with the each page the time of that page’s last use.

Set page_fault=0 & frame_size to the value given as input.Write a program to simulate Least Recently Used (LRU) page replacement algorithm for the following page reference string: 9, 10, 11, 7, 12, 8, 7, 6, 12, 5, 4, 3, 10, 11, 12, 4, 5, 6, 9, 4, 5.Ĭonsider (i) 4 frames and (ii) 5 frames. Submitted by Radib Kar, on November 21, 2018 In this article, we are going to see how no of page faults changes with increase in frame size in LRU replacement policy?