System Software Lab 9 | Read Now

System Software VTU Lab

Program 9:- Design, develop and implement a C/C++/Java program to implement page replacement algorithms LRU and FIFO. Assume suitable input required to demonstrate the results

System Software Lab9 code [lab9.c]

#include<stdio.h>
#include<stdlib.h>

void FIFO(char [ ],char [ ],int,int);
void lru(char [ ],char [ ],int,int);
void opt(char [ ],char [ ],int,int);

int main()
{
    int ch,YN=1,i,l,f;
    char F[10],s[25];
    printf("\nEnter the no of empty frames: ");
    scanf("%d",&f);
    printf("\nEnter the length of the string: ");
    scanf("%d",&l);
    printf("\nEnter the string: ");
    scanf("%s",s);
    for(i=0;i<f;i++)
        F[i]=-1;

    do
    {
        printf("\n*********** MENU ***********");
        printf("\n1:FIFO\n2:LRU \n3:EXIT");
        printf("\nEnter your choice: ");
        scanf("%d",&ch);

        switch(ch)
        {
            case 1: for(i=0;i<f;i++)
                        F[i]=-1;
                    FIFO(s,F,l,f);
                    break;

            case 2: for(i=0;i<f;i++)
                        F[i]=-1;
                    lru(s,F,l,f);
                    break;

            case 3: exit(0);
        }
        printf("\n\nDo u want to continue IF YES PRESS 1\nIF NO PRESS 0 : ");
        scanf("%d",&YN);
    } while(YN==1);
    return(0);
}


void FIFO(char s[],char F[],int l,int f)
{
    int i,j=0,k,flag=0,cnt=0;
    printf("\n\tPAGE\t FRAMES\t\t\t FAULTS");
    for(i=0;i<l;i++)
    {
        for(k=0;k<f;k++)
        {
            if(F[k]==s[i])
                flag=1;
        }

        if(flag==0)
        {
            printf("\n\t%c\t",s[i]);
            F[j]=s[i];
            j++;
            for(k=0;k<f;k++)
                printf(" %c",F[k]);
            printf("\tPage-fault%d",cnt);
            cnt++;
        }

        else
        {
            flag=0;
            printf("\n\t%c\t",s[i]);
            for(k=0;k<f;k++)
                printf(" %c",F[k]);
            printf("\tNo page-fault");
        }
        if(j==f)
            j=0;
    }
}


void lru(char s[],char F[],int l,int f)
{
    int i,j=0,k,m,flag=0,cnt=0,top=0;
    printf("\n\tPAGE\t FRAMES\t\t\t FAULTS");
    for(i=0;i<l;i++)
    {
        for(k=0;k<f;k++)
        {
            if(F[k]==s[i])
            {
                flag=1;
                break;
            }
        }
        printf("\n\t%c\t",s[i]);
        if(j!=f && flag!=1)
        {
            F[top]=s[i];
            j++;
            if(j!=f)
                top++;
        }

        else
        {
            if(flag!=1)
            {
                for(k=0;k<top;k++)
                    F[k]=F[k+1];
                F[top]=s[i];
            }

            if(flag==1)
            {
                for(m=k;m<top;m++)
                    F[m]=F[m+1];
                F[top]=s[i];
            }
        }

        for(k=0;k<f;k++)
            printf(" %c",F[k]);

        if(flag==0)
        {
            printf("\tPage-fault%d",cnt);
            cnt++;
        }
        else
            printf("\tNo page fault");
        flag=0;
    }
}

Output