Really need your help to figure out what is going on. The code seem to be so trivial, but it produces wrong output.
It is a basic producer-consumer problem. Generator thread generates prime numbers and consumer (acceptors) must process them. In App I created two acceptors and 1 generator thread. The problem is that I get the following output for 50 as a bound:
Thread Thread-2 puts 47
Thread Thread-2 puts 43
Thread Rob gets 47
Thread Rob gets 43
Thread Thread-1 gets 47
Thread Nick puts 47
etc...
I have no idea why Thread-2 and Thread-1 are printed... where these threads are coming from? Thanks
public class PrimeGenerator implements Runnable{
private PrimeCentral primeCentral;
int bound;
public PrimeGenerator(PrimeCentral PC, int bound){
this.primeCentral = PC;
this.bound = bound;
new Thread(this).start();
}
@Override
public void run() {
int n=bound;
while (n > 1) {
int d;
for (d=2; d <= n/2; d++)
if ((n % d) == 0) break;
if (d > n/2) {
primeCentral.put(n);
System.out.println("Thread " + Thread.currentThread().getName() + " puts " + n);
}
n--;
}
}
}
public class PrimeCentral {
private int prime;
private boolean available = false;
public synchronized void put(int n){
while(available == true){
try{
wait();
}catch(InterruptedException e){}
}
prime = n;
available = true;
notifyAll();
}
public synchronized int get(){
while(available == false){
try{
wait();
}catch(InterruptedException e){}
}
available = false;
notifyAll();
return prime;
}
}
public class PrimeAcceptor implements Runnable{
private PrimeCentral primeCentral;
public PrimeAcceptor(PrimeCentral primeCentral){
this.primeCentral = primeCentral;
new Thread(this).start();
}
public void run() {
while (true) {
int prime = primeCentral.get();
System.out.println("Thread " + Thread.currentThread().getName() + " gets " + prime);
if (prime == 2) break;
}
}
public class App {
public static void main(String[] args) {
PrimeCentral pc = new PrimeCentral();
new Thread(new PrimeAcceptor(pc), "Bob").start();
new Thread(new PrimeAcceptor(pc), "Rob").start();
new Thread(new PrimeGenerator(pc, 50), "Nick").start();
}
}
EDIT: sorry people I was dumb with this stupid mistake
