Why does an IllegalThreadStateException occur when Thread.start is called again

Question

public class SieveGenerator{

static int N = 50;
public static void main(String args[]){

    int cores = Runtime.getRuntime().availableProcessors();

    int f[] =          


        

Answer 1

The Thread.isAlive() method can tell you if the Thread has already been started. Simply do this where you want to start your thread:

   if(!t[p%cores].isAlive()){
       t[p%cores].start();
   }