இராய் அந்தோனி அர்னால்டு
Roy
//CPU Scheduling algorithms
//FCFS, Round Robin and Shortest Job First
#include<iostream.h>
#include<conio.h>
#include<stdio.h>
class cpuschedule
{
int n,bu[20];
float twt,awt,wt[20],tat[20];
public:
void Getdata();
void fcfs();
void sjf();
void roundrobin();
};
//Getting no of processes and Burst time
void cpuschedule::Getdata()
{
int i;
cout<<”Enter the no of processes:”;
cin>>n;
for(i=1;i<=n;i++)
{
cout<<”\nEnter The BurstTime for Process p”<<i<<”=”;
cin>>bu[i];
}
}
//First come First served Algorithm
void cpuschedule::fcfs()
{
int i,b[10];
float sum=0.0;
twt=0.0;
for(i=1;i<=n;i++)
{
b[i]=bu[i];
cout<<”\nBurst time for process p”<<i<<”=”;
cout<<b[i];
}
wt[1]=0;
for(i=2;i<=n;i++)
{
wt[i]=b[i-1]+wt[i-1];
}
for(i=1;i<=n;i++)
{
twt=twt+wt[i];
tat[i]=b[i]+wt[i];
sum+=tat[i];
}
awt=twt/n;
sum=sum/n;
cout<<”\nTotal Waiting Time=”<<twt;
cout<<”\nAverage Waiting Time=”<<awt;
cout<<”\nAverage Turnaround time=”<<sum;
}
//Shortest job First Algorithm
void cpuschedule::sjf()
{
int i,j,temp,b[10];
float sum=0.0;
twt=0.0;
for(i=1;i<=n;i++)
{
b[i]=bu[i];
cout<<”\nBurst time for process p”<<i<<”=”;
cout<<b[i];
}
for(i=n;i>=1;i–)
{
for(j=2;j<=n;j++)
{
if(b[j-1]>b[j])
{
temp=b[j-1];
b[j-1]=b[j];
b[j]=temp;
}
}
}
wt[1]=0;
for(i=2;i<=n;i++)
{
wt[i]=b[i-1]+wt[i-1];
}
for(i=1;i<=n;i++)
{
twt=twt+wt[i];
tat[i]=b[i]+wt[i];
sum+=tat[i];
}
awt=twt/n;
sum=sum/n;
cout<<”\nTotal Waiting Time=”<<twt;
cout<<”\nAverage Waiting Time=”<<awt;
cout<<”\nAverage turnaround time=”<<sum;
}
//Round Robin Algorithm
void cpuschedule::roundrobin()
{
int i,j,tq,k,b[10],Rrobin[10][10],count[10];
int max=0;
int m;
float sum=0.0;
twt=0.0;
for(i=1;i<=n;i++)
{
b[i]=bu[i];
cout<<”\nBurst time for process p”<<i<<”=”;
cout<<b[i];
if(max<b[i])
max=b[i];
wt[i]=0;
}
cout<<”\nEnter the Time Quantum=”;
cin>>tq;
//TO find the dimension of the Round robin array
m=max/tq+1;
//initializing Round robin array
for(i=1;i<=n;i++)
{
for(j=1;j<=m;j++)
{
Rrobin[i][j]=0;
}
}
//placing value in the Rrobin array
i=1;
while(i<=n)
{
j=1;
while(b[i]>0)
{
if(b[i]>=tq)
{
b[i]=b[i]-tq;
Rrobin[i][j]=tq;
j++;
}
else
{
Rrobin[i][j]=b[i];
b[i]=0;
j++;
}
}
count[i]=j-1;
i++;
}
cout<<”Display”;
for(i=1;i<=n;i++)
{
for(j=1;j<=m;j++)
{
cout<<”\nRr["<<i<<","<<j<<"]=”<<Rrobin[i][j];
cout<<” “;
}
cout<<”\ncount=”<<count[i];
}
for(j=1;j<=n;j++)
{
for(i=1;i<=count[j];i++)
{
if(i==count[j])
{
for(k=1;k<j;k++)
{
if(k!=j)
wt[j]+=Rrobin[k][i];
}
}
else
for(k=1;k<=n;k++)
{
if(k!=j)
wt[j]+=Rrobin[k][i];
}
}
}
for(i=1;i<=n;i++)
cout<<”\nWaiting Time for process P”<<i<<”=”<<wt[i];
//calculating Average Weighting Time
for(i=1;i<=n;i++)
{
twt=twt+wt[i];
tat[i]=b[i]+wt[i];
sum+=tat[i];
}
awt=twt/n;
sum=sum/n;
cout<<”\nTotal Waiting Time=”<<twt;
cout<<”\nAverage Waiting Time=”<<awt;
cout<<”\nAverage turnaround time=”<<sum;
}
void main()
{
int ch=0,cho;
cpuschedule c;
clrscr();
do
{
switch(ch)
{
case 0:
cout<<”\n0.MENU”;
cout<<”\n1.Getting BurstTime”;
cout<<”\n2.FirstComeFirstServed”;
cout<<”\n3.ShortestJobFirst”;
cout<<”\n4.RoundRobin”;
cout<<”\n5.EXIT”;
break;
case 1:
c.Getdata();
break;
case 2:
cout<<”FIRST COME FIRST SERVED SCHEDULING”;
c.fcfs();
break;
case 3:
cout<<”SHORTEST JOB FIRST SCHEDULING”;
c.sjf();
break;
case 4:
cout<<”ROUND ROBIN SCHEDULING”;
c.roundrobin();
break;
case 5:
break;
}
cout<<”\nEnter your choice:”;
cin>>ch;
getch();
}while(ch<5);
}
8 Comments
Sorry, the comment form is closed at this time.
Thanks for the source code.
It might be very much better if it was in C language.
it,s also should be in clanguage and java language
thanks dear it should be also in c lan
Sir,
Please give program code with output…Thanking You !!!
By:
Dushyant Kumar Shivhare
if i do that then the students never execute the program…
because of that only i didn’t show much interest in displaying output…
thanks for source code……….. it is very much useful
if you send mail how output would be……….
it is very useful…….
my id govinth008@gmail.com
and as well as give some important notes related to each program…..
thank u arnold sir
gokul
from chennai….
very helpful code..we will appreciate it…looking for more in future also..thankx
i need the program with the arrival time for the scheduling algorithms