Implement FIFO (First-In-First-Out) Algorithm


Pages are in following order:
2 3 2 1 5 2 4 5 3 2 5 2

#include<stdio.h>
#include<conio.h>

int frame[3];
void main()
{
void display();
int i,j,page[12]={2,3,2,1,5,2,4,5,3,2,5,2};
int flag1=0,flag2=0,pf=0,framesize=3,top=0;
clrscr();
for(i=0;i<3;i++)
{
frame[i]=0;
}
for(j=0;j<12;j++)
{
flag1=0;
flag2=0;
for(i=0;i<12;i++)
{
if(frame[i]==page[j])
{
flag1=1;
flag2=1;
break;
}
}
if(flag1==0)
{
for(i=0;i<framesize;i++)
{
if(frame[i]==0)
{
frame[i]=page[j];
flag2=1;
break;
}
}
}
if(flag2==0)
{
frame[top]=page[j];
top++;
pf++;
if(top>=framesize)
top=0;
}
display();
}
printf("\n\n\tNumber of page faults  : %d ",pf);
getch();
}
void display()
{
int i;
printf("\n");
for(i=0;i<3;i++)
printf("\t%d",frame[i]);

}


Output:

2 0 0
2 3 0
2 3 0
2 3 1
5 3 1
5 2 1
5 2 4
5 2 4
3 2 4
3 2 4
3 5 4
3 5 2


Number of page faults : 6
Previous Post Next Post