System Software Lab 7 | Read Now
System Software VTU Lab
Program 7:- Design, develop and implement a C/C++/Java program to simulate the working of Shortest remaining time and Round Robin (RR) scheduling algorithms. Experiment with different quantum sizes for RR algorithm.
System Software Lab7 Code [lab7.c]
// CPU Scheduling -Round Robin
#include<stdio.h>
struct process
{
char name;
int at,bt,wt,tt,rt;
int completed;
}p[10];
int n;
int q[10]; //queue
int front=-1,rear=-1;
void enqueue(int i)
{
if(rear==10)
printf("overflow");
rear++;
q[rear]=i;
if(front==-1)
front=0;
}
int dequeue()
{
if(front==-1)
printf("underflow");
int temp=q[front];
if(front==rear)
front=rear=-1;
else
front++;
return temp;
}
int isInQueue(int i)
{
int k;
for(k=front;k<=rear;k++)
{
if(q[k]==i)
return 1;
}
return 0;
}
void sortByArrival()
{
struct process temp;
int i,j;
for(i=0;i<n-1;i++)
{
for(j=i+1;j<n;j++)
{
if(p[i].at>p[j].at)
{
temp=p[i];
p[i]=p[j];
p[j]=temp;
}
}
}
}
int main()
{
int i,j,time=0,sum_bt=0,tq;
char c;
float avgwt=0;
printf("Enter Number of Processes:\n");
scanf("%d",&n);
for(i=0,c='A';i<n;i++,c++)
{
p[i].name=c;
printf("\nProcess %c\n",c);
printf("\tArrival Time :");
scanf("%d",&p[i].at);
printf("\tBurst Time :");
scanf("%d",&p[i].bt);
p[i].rt=p[i].bt;
p[i].completed=0;
sum_bt+=p[i].bt;
}
printf("\nEnter the time quantum:");
scanf("%d",&tq);
sortByArrival();
enqueue(0);
printf("\nProcess execution order: ");
for(time=p[0].at;time<sum_bt;)
{
i=dequeue();
if(p[i].rt<=tq)
{
time+=p[i].rt;
p[i].rt=0;
p[i].completed=1;
printf(" %c ",p[i].name);
p[i].wt=time-p[i].at-p[i].bt;
p[i].tt=time-p[i].at;
for(j=0;j<n;j++)
{
if(p[j].at<=time && p[j].completed!=1&& isInQueue(j)!=1)
{
enqueue(j);
}
}
}
else
{
time+=tq;
p[i].rt-=tq;
printf(" %c ",p[i].name);
for(j=0;j<n;j++)
{
if(p[j].at<=time && p[j].completed!=1&&i!=j&& isInQueue(j)!=1)
{
enqueue(j);
}
}
enqueue(i);
}
}
printf("\n\nName\tArrival Time\tBurst Time\tResponse Time\tTurnAround Time");
for(i=0;i<n;i++)
{
avgwt+=p[i].wt;
printf("\n%c\t\t%d\t\t%d\t\t%d\t\t%d",p[i].name,p[i].at,p[i].bt,p[i].wt,p[i].tt);
}
printf("\n\nAverage waiting time:%f",avgwt/n);
}
// CPU Scheduling -Round Robin
#include<stdio.h>
struct process
{
char name;
int at,bt,wt,tt,rt;
int completed;
}p[10];
int n;
int q[10]; //queue
int front=-1,rear=-1;
void enqueue(int i)
{
if(rear==10)
printf("overflow");
rear++;
q[rear]=i;
if(front==-1)
front=0;
}
int dequeue()
{
if(front==-1)
printf("underflow");
int temp=q[front];
if(front==rear)
front=rear=-1;
else
front++;
return temp;
}
int isInQueue(int i)
{
int k;
for(k=front;k<=rear;k++)
{
if(q[k]==i)
return 1;
}
return 0;
}
void sortByArrival()
{
struct process temp;
int i,j;
for(i=0;i<n-1;i++)
{
for(j=i+1;j<n;j++)
{
if(p[i].at>p[j].at)
{
temp=p[i];
p[i]=p[j];
p[j]=temp;
}
}
}
}
int main()
{
int i,j,time=0,sum_bt=0,tq;
char c;
float avgwt=0;
printf("Enter Number of Processes:\n");
scanf("%d",&n);
for(i=0,c='A';i<n;i++,c++)
{
p[i].name=c;
printf("\nProcess %c\n",c);
printf("\tArrival Time :");
scanf("%d",&p[i].at);
printf("\tBurst Time :");
scanf("%d",&p[i].bt);
p[i].rt=p[i].bt;
p[i].completed=0;
sum_bt+=p[i].bt;
}
printf("\nEnter the time quantum:");
scanf("%d",&tq);
sortByArrival();
enqueue(0);
printf("\nProcess execution order: ");
for(time=p[0].at;time<sum_bt;)
{
i=dequeue();
if(p[i].rt<=tq)
{
time+=p[i].rt;
p[i].rt=0;
p[i].completed=1;
printf(" %c ",p[i].name);
p[i].wt=time-p[i].at-p[i].bt;
p[i].tt=time-p[i].at;
for(j=0;j<n;j++)
{
if(p[j].at<=time && p[j].completed!=1&& isInQueue(j)!=1)
{
enqueue(j);
}
}
}
else
{
time+=tq;
p[i].rt-=tq;
printf(" %c ",p[i].name);
for(j=0;j<n;j++)
{
if(p[j].at<=time && p[j].completed!=1&&i!=j&& isInQueue(j)!=1)
{
enqueue(j);
}
}
enqueue(i);
}
}
printf("\n\nName\tArrival Time\tBurst Time\tResponse Time\tTurnAround Time");
for(i=0;i<n;i++)
{
avgwt+=p[i].wt;
printf("\n%c\t\t%d\t\t%d\t\t%d\t\t%d",p[i].name,p[i].at,p[i].bt,p[i].wt,p[i].tt);
}
printf("\n\nAverage waiting time:%f",avgwt/n);
}
// CPU Scheduling -Round Robin #include<stdio.h> struct process { char name; int at,bt,wt,tt,rt; int completed; }p[10]; int n; int q[10]; //queue int front=-1,rear=-1; void enqueue(int i) { if(rear==10) printf("overflow"); rear++; q[rear]=i; if(front==-1) front=0; } int dequeue() { if(front==-1) printf("underflow"); int temp=q[front]; if(front==rear) front=rear=-1; else front++; return temp; } int isInQueue(int i) { int k; for(k=front;k<=rear;k++) { if(q[k]==i) return 1; } return 0; } void sortByArrival() { struct process temp; int i,j; for(i=0;i<n-1;i++) { for(j=i+1;j<n;j++) { if(p[i].at>p[j].at) { temp=p[i]; p[i]=p[j]; p[j]=temp; } } } } int main() { int i,j,time=0,sum_bt=0,tq; char c; float avgwt=0; printf("Enter Number of Processes:\n"); scanf("%d",&n); for(i=0,c='A';i<n;i++,c++) { p[i].name=c; printf("\nProcess %c\n",c); printf("\tArrival Time :"); scanf("%d",&p[i].at); printf("\tBurst Time :"); scanf("%d",&p[i].bt); p[i].rt=p[i].bt; p[i].completed=0; sum_bt+=p[i].bt; } printf("\nEnter the time quantum:"); scanf("%d",&tq); sortByArrival(); enqueue(0); printf("\nProcess execution order: "); for(time=p[0].at;time<sum_bt;) { i=dequeue(); if(p[i].rt<=tq) { time+=p[i].rt; p[i].rt=0; p[i].completed=1; printf(" %c ",p[i].name); p[i].wt=time-p[i].at-p[i].bt; p[i].tt=time-p[i].at; for(j=0;j<n;j++) { if(p[j].at<=time && p[j].completed!=1&& isInQueue(j)!=1) { enqueue(j); } } } else { time+=tq; p[i].rt-=tq; printf(" %c ",p[i].name); for(j=0;j<n;j++) { if(p[j].at<=time && p[j].completed!=1&&i!=j&& isInQueue(j)!=1) { enqueue(j); } } enqueue(i); } } printf("\n\nName\tArrival Time\tBurst Time\tResponse Time\tTurnAround Time"); for(i=0;i<n;i++) { avgwt+=p[i].wt; printf("\n%c\t\t%d\t\t%d\t\t%d\t\t%d",p[i].name,p[i].at,p[i].bt,p[i].wt,p[i].tt); } printf("\n\nAverage waiting time:%f",avgwt/n); }