IMPLEMENTATION OF LRU PAGE REPLACEMENT ALGORITHM

-

 IMPLEMENTATION OF LRU PAGE REPLACEMENT ALGORITHM

AIM:

To write a c program to implement LRU page replacement algorithm

ALGORITHM :

1. Start the process

2. Declare the size

3. Get the number of pages to be inserted

4. Get the value

5. Declare counter and stack

6. Select the least recently used page by counter value

7. Stack them according the selection.

8.  Display the values

9. Stop the process

PROGRAM:
#include<stdio.h>
main()
{
int q[20],p[50],c=0,c1,d,f,i,j,k=0,n,r,t,b[20],c2[20];
printf("Enter no of pages:");
scanf("%d",&n);
printf("Enter the reference string:");
for(i=0;i<n;i++)
            scanf("%d",&p[i]);
printf("Enter no of frames:");
scanf("%d",&f);
q[k]=p[k];
printf("\n\t%d\n",q[k]);
c++;
k++;
for(i=1;i<n;i++)
            {
                        c1=0;
                        for(j=0;j<f;j++)
                        {
                                    if(p[i]!=q[j])
                                    c1++;
                        }
                        if(c1==f)
                        {
                                    c++;
                                    if(k<f)
                                    {
                                                q[k]=p[i];
                                                k++;
                                                for(j=0;j<k;j++)
                                                printf("\t%d",q[j]);
                                                printf("\n");
                                    }
                                    else
                                    {
                                                for(r=0;r<f;r++)
                                                {
                                                            c2[r]=0;
                                                            for(j=i-1;j<n;j--)
                                                            {
                                                            if(q[r]!=p[j])
                                                            c2[r]++;
                                                            else
                                                            break;
                                                }
                                    }
                                    for(r=0;r<f;r++)
                                     b[r]=c2[r];
                                    for(r=0;r<f;r++)
                                    {
                                                for(j=r;j<f;j++)
                                                {
                                                            if(b[r]<b[j])
                                                            {
                                                                        t=b[r];
                                                                        b[r]=b[j];
                                                                        b[j]=t;
                                                            }
                                                }
                                    }
                                    for(r=0;r<f;r++)
                                    {
                                                if(c2[r]==b[0])
                                                q[r]=p[i];
                                                printf("\t%d",q[r]);
                                    }
                                    printf("\n");
                        }
            }
}
printf("\nThe no of page faults is %d",c);
}

Comments

Post a Comment

Popular posts from this blog

PHP Array Functions

-
  PHP  Array  Functions The array functions allow you to access and manipulate arrays. Simple and multi-dimensional arrays are supported. Function Description array() Creates an array array_column() Returns the values from a single column in the input array array_combine() Creates an array by using the elements from one "keys" array and one "values" array array_flip() Flips/Exchanges all keys with their associated values in an array array_pop() Deletes the last element of an array array_push() Inserts one or more elements to the end of an array array_replace() Replaces the values of the first array with the values from following arrays array_reverse() Returns an array in the reverse order array_search() Searches an array for a given value
Read more

String Functions in C Language(C Language)

-
  C String Functions There are many important string functions defined in "string.h" library. No. Function Description 1) strlen(string_name) returns the length of string name. 2) strcpy(destination, source) copies the contents of source string to destination string. 3) strcat(first_string, second_string) concats or joins first string with second string. The result of the string is stored in first string. 4) strcmp(first_string, second_string) compares the first string with second string. If both strings are same, it returns 0. 5) strrev(string) returns reverse string. 6) strlwr(string) returns string characters in lowercase. 7) strupr(string) returns string characters in uppercase. 8) strstr( st
Read more

Object Instance Working with Strings

-
  Classes are nothing without objects.We can create multiple objects from a class. Each object has all the properties and methods defined in the class, but they will have different property values. An object of a class is created using the new keyword. Example: $bsc and $bzc is instances of the class Group: <?php class Group { public $name; function set_name($name) {     $this->name=$name; } function get_name; {     return $this->name; } } $bsc=new Group(); $bzc=new Group(); $bsc->set_name('BSC'); $bzc->set_name('BZC'); echo $bsc->get_name(; echo "<br>"; echo $bzc->get_name(); ?>
Read more