PROGRAM TO IMPLEMENT ROUND ROBIN SCHEDULING

import java.io.DataInputStream;

import java.io.IOException;

import datastruct.LinkedQueue;

import datastruct.Node;

/*

@author athiruban

PROGRAM TO IMPLEMENT ROUND ROBIN SCHEDULING

***/



public class App

{

static String[] process_name=null;

static int[] burst_time=null;

static int[] waiting_time=null;

static int[] turnaroundtime =null;

static int noofproc=0;

static DataInputStream dis = new DataInputStream(System.in);

static LinkedQueue lq;

static int exectime=0;

static boolean processed=false;

static int timeslice=0;

public static void readInfo()

{

processed = false;

System.out.print("\n\tEnter No Of Process : ");

try{

noofproc = Integer.parseInt(dis.readLine() ); } catch(IOException ioe){ }

//allocate memory

process_name = new String[noofproc];

burst_time = new int[noofproc];

waiting_time = new int[noofproc];

turnaroundtime = new int[noofproc];

lq = new LinkedQueue();

for(int i = 0;i<noofproc;i++)

{

System.out.print("\n\tEnter Process Name : ");



try{

process_name[i] = dis.readLine(); } catch(IOException ioe){ }

System.out.print("\n\tEnter Burst time : ");



try{

burst_time[i] = Integer.parseInt(dis.readLine() ); } catch(IOException ioe){ }

lq.addLast(process_name[i],burst_time[i]);

}

}

public static int getBurstByName(String str)

{

for(int i = 0 ;i<noofproc;i++) { if( str.equals(process_name[i]) ) return burst_time[i]; }

return 0;

}

public static int getIdByName(String str)

{

for(int i = 0 ;i<noofproc;i++) { if( str.equals(process_name[i]) ) return i; }

return 0;

}

public static void displayStatistics()

{

double wt=0;

double tt = 0;

if(processed==false){ System.out.println("Locked"); return; }

System.out.println("\nProcess Execution Statistics");

System.out.println("----------------------------");

System.out.println("\nProcessName\t"+"BurstTime\t"+"waitingTime\t"+"Turnaround Time");

for(int i =0;i<noofproc;i++)

{

System.out.println(process_name[i]+"\t\t"+burst_time[i]+"\t\t"+waiting_time[i]+"\t\t"+turnaroundtime[i]);

wt += waiting_time[i];

tt += turnaroundtime[i];

}

System.out.println("\n\tCPU Time Slice is :"+timeslice+" ms");

System.out.println("\n\tAverage Waiting Time is :"+(wt/noofproc)+" ms");

System.out.println("\n\tAverage Turnaround Time is :"+(tt/noofproc)+" ms");

System.out.println("\n\tTotal Execution Time is : "+exectime+" ms");

}

public static void process()

{

Node tnode; // reference

if(process_name == null){System.out.println("Locked");return;}

System.out.println("INITIAL STAGE");

lq.display();

System.out.print("\n\tENTER TIME SLICE > ");

try{

timeslice = Integer.parseInt(dis.readLine());

}catch(IOException ioe){ }



while(lq.getSize()>0)

{

tnode = lq.removeFirst();

if(tnode.p_no >= timeslice) {

exectime += timeslice;

tnode.p_no -= timeslice;

}

else if(tnode.p_no > 0 && tnode.p_no < timeslice) {

exectime += tnode.p_no;

tnode.p_no =0;

}

if(tnode.p_no > 0)

lq.addLast(tnode.name,tnode.p_no);

else {

System.out.println("\tP r o c e s s "+tnode.name+" i s t e r m i n a t e d");

waiting_time[getIdByName(tnode.name)]=exectime-getBurstByName(tnode.name);

turnaroundtime[getIdByName(tnode.name)]

=waiting_time[getIdByName(tnode.name)]+burst_time[getIdByName(tnode.name)];

}

lq.display();

System.out.println("\t=--------------------------------------------------=");

try{ dis.read(); } catch(IOException ioe){ }

}

processed = true;

}

public static void main(String args[])

{

int ichoice=0;

L1:

do{

System.out.println("\n\n");

System.out.println("\tIMPLEMENTING ROUND ROBIN SCHEDULING");

System.out.println("\t-----------------------------------");

System.out.println("\t1 TO READ DETAILS");

System.out.println("\t2 TO PROCESS QUEUE");

System.out.println("\t3 TO DISPLAY STATISTICS");

System.out.println("\t4 TO EXIT");

System.out.print("\n\tYour Choice > ");

try{ ichoice = Integer.parseInt(dis.readLine() ); } catch(IOException ioe){ }

switch(ichoice)

{

case 1: readInfo();

break;

case 2: process();

break;

case 3: displayStatistics();

break;

case 4:

break L1;

default:

break;

}

} while(true);

}

}