import java.util.Scanner;


public class CountingThread implements Runnable{

	//total for counting
	private long value;
	
	//how a thread identifies itself
	private int id;
	
	//declared as volatile --explain later
	private volatile boolean done;
	
	//public static long total = 0;
	public static Data shared = new Data();
	
	
	public CountingThread(int id){
		this.id = id;
		value = 0;
		done = false;
	}
	
	//run method gets called as a result of a call to 
	//start
	public void run(){
		while(!done){
			value++;
			//total++;
			shared.addOne();
		}
		System.out.printf("Thread %d has value %d\n", id, value);
		//once run is done, the thread ends
	}
	
	//request that is thread stop
	public void pleaseStop(){
		done = true;
	}
	
	public long getValue(){
		return value;
	}
	/**
	 * @param args
	 */
	public static void main(String[] args) {
		CountingThread[] counters = new CountingThread[10];
		
		for(int i = 0; i < counters.length; i++){
			counters[i] = new CountingThread(i);
			//create a thread that runs the current counter
			Thread t = new Thread(counters[i]);
			
			//start the thread, which will cause run to be called.
			t.start();
		}

		Scanner in = new Scanner(System.in);
		
		System.out.println("Type something to stop the threads: ");
		
		//wait for something to be typed
		in.next();
		
		//ask each thread to stop
		for(CountingThread ct: counters){
			ct.pleaseStop();
		}
		
		//stall while the threads finish up
		System.out.println("Type somethihng to end: ");
		in.next();
		
		long allValues = 0;
		for(CountingThread ct: counters){
			allValues += ct.getValue();
		}
		System.out.println("Sum of all values: " +allValues);
		System.out.println("Total: " + shared.getTotal());
	}

}

class Data {
	private long total = 0;
	
	//only one thread can be executing a synchronized method at a time
	//a thread must get a lock (on this object) to run this method
	//it will unlock, when it is done
	public synchronized void addOne(){
		total++;
	}
	
	public long getTotal(){
		return total;
	}
}