Code of Round-robin scheduling in c?

Answer 1

#include<stdio.h>

#include<conio.h>

main()

{

int st[10],bt[10],wt[10],tat[10],n,tq;

int i,count=0,swt=0,stat=0,temp,sq=0;

float awt=0.0,atat=0.0;

clrscr();

printf("Enter number of processes:");

scanf("%d",&n);

printf("Enter burst time for sequences:");

for(i=0;i<n;i++)

{

scanf("%d",&bt[i]);

st[i]=bt[i];

}

printf("Enter time quantum:");

scanf("%d",&tq);

while(1)

{

for(i=0,count=0;i<n;i++)

{

temp=tq;

if(st[i]==0)

{

count++;

continue;

}

if(st[i]>tq)

st[i]=st[i]-tq;

else

if(st[i]>=0)

{

temp=st[i];

st[i]=0;

}

sq=sq+temp;

tat[i]=sq;

}

if(n==count)

break;

}

for(i=0;i<n;i++)

{

wt[i]=tat[i]-bt[i];

swt=swt+wt[i];

stat=stat+tat[i];

}

awt=(float)swt/n;

atat=(float)stat/n;

printf("Process_no Burst time Wait time Turn around time

");

for(i=0;i<n;i++)

printf("%d %d %d %d

",i+1,bt[i],wt[i],tat[i]);

printf("Avg wait time is %f

Avg turn around time is %f",awt,atat);

getch();

}

Answer 2

#include
#include
#include
void main()
{
clrscr();
int bt[10],n,i,slot,totaltime=0;
cout<<"enter the number of processes:"<cin>>n;
cout<<"enter the time slot:"<cin>>slot;
for(i=1;i<=n;i++)
{
cout<<"enter the burst time for process p"<cin>>bt[i];
}
cout<<"\n\nprocess\t\tburst-time"<for(i=1;i<=n;i++)
{
cout<<"\nP"<}
cout<<"\n\n";
i=1;
while(totaltime!=0)
{
for(i=1;i<=n;i++)
{
if(bt[i]>0)
{
cout<<"process p "<if(bt[i]>slot)
{
delay(slot*1000);
bt[i]-=slot;
totaltime-=slot;
}
else
{
delay(bt[i]*1000);
totaltime-=bt[i];
bt[i]=0;
cout<<"process p"<}
}
}
}
getch();
}

Answer 3

#include<stdio.h>

#include<stdlib.h>

#include<pthread.h>

struct nodek {

int arrival_time;

int burst_time;

struct nodek *nextk;

struct nodek *prev;

int pid;

//int priority;

};

void disp(int count,struct nodek *last);

struct nodek *headk;

struct nodek *last;

struct nodek *last1;

int count=0,count1=0;//count1 pid counter;

int count3=0;//time counter

int time_quantum;

void runner(int *param);

void sjf();

void rr();

struct nodek *add(struct nodek *headk);

void main(){

int i;

printf("for fcfs press 1 ,for rr press 2 and for sjf press 3 to exit press 0");

while(1){

printf("enter number");

scanf("%d",&i);

if(i==1){

fcfs();

}

if(i==2){

rr();

}

if(i==3){

sjf();

}

if(i==0){

break ;

}

}

}

void rr(){

pthread_t th1;

pthread_attr_t attr;

int i;

int count;

struct nodek *temp;

headk=malloc(sizeof(struct nodek));

last=headk;

last1=last;

//newk=headk;

int n,j,m,flag,val,pos,status;

printf("\nenter time quantum:");

scanf("%d",&time_quantum);

printf("to intialize enter 3 processes\n");

n=3;

for(i=0;i<n-1;i++)

{

printf("enter the burst_time: ");

scanf("%d",&headk->burst_time);

headk->arrival_time=count1;

count3++;

temp=headk;

headk->nextk=malloc(sizeof(struct nodek));

headk=headk->nextk;

headk->prev=temp;

count1++;

temp->pid=count1;

count++;

}

printf("enter the burst_time: ");

scanf("%d",&headk->burst_time);

headk->arrival_time=count1;

headk->prev=temp;

count1++;

headk->pid=count1;

count++;

headk->nextk=last;

disp(count,last);

printf("to enter a process in between enter a\n");

printf("to continue rr enter 1:\n");

scanf("%d",&j);

while(j==1){

char c;

//assuming that the proceess comes one by one no two process come at the same time.

if(kbhit())

{

c = fgetc(stdin);

if(c=='a'){

count1++;

headk=add(headk);

count++;

disp(count,last);

fflush(stdin);

}

}

else{

pthread_create(&th1,NULL,&runner,(int *)&(last1->burst_time));

pthread_join(th1,NULL);

}

if(last==NULL){

break;

}

}

}

void runner(int *param){

int x,i;

char c;

struct nodek *temp;

x = *((int *) param);

for(i=0;i<time_quantum;i++){

if(kbhit())

{

c = fgetc(stdin);

if(c=='a'){

count1++;

headk=add(headk);

printf("%d\n",headk->burst_time);

disp(count1,last);

fflush(stdin);

}

}

sleep(1);

count3++;

last1->burst_time--;

if(last1->burst_time==0){

break;

}

}

printf("process:%d\n",last1->pid);

//if the first one gets deleted then last would actually point to null.

if(last1->burst_time==0){

struct nodek *flag=last1;

printf("process %d finished \n",flag->pid);

last1=last1->nextk;

last1->prev=flag->prev;

if(!(last==last1)){

(flag->prev)->nextk=last1;}

printf("kl\n");

free(flag);

if(last==NULL){

printf("hello\n");

last=last1;

}

printf("hell\n");

pthread_exit(0);

}

else{

last1=last1->nextk;

pthread_exit(0);

}

}

struct nodek *add(struct nodek *headk){

struct nodek *temp1=malloc(sizeof(struct nodek));

printf("enter the burst time of the process");

scanf("%d",&temp1->burst_time);

temp1->arrival_time=count3++;

temp1->nextk=headk->nextk;

headk->nextk=temp1;

temp1->prev=headk;

headk=temp1;

headk->pid=count1;

count1++;

headk->nextk=last;

return headk;

}

void disp(int count,struct nodek *last){

int j;

struct nodek *temp1=last;

for(j=0;j<count1;j++){

printf("count :%d,%d\n",count1,temp1->burst_time);

temp1=temp1->nextk;

}

}

void sjf(){

}

fcfs(){

}