ThreadSafety.java

public class ThreadSafety implements Runnable {

  public Integer i = 0;
	
	@Override
	public void run() {	
		try {
			increment(this);
			increment2();
		} catch (InterruptedException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		
	}

	public static void increment(ThreadSafety ts) throws InterruptedException{
		
		while(ts.i < 1000){
			Thread.sleep(10);
			ts.i += 1;
			System.out.println(ts.i);
		}
		System.out.println("Final");
		System.out.println(ts.i);
	}
	
	public static void increment2() throws InterruptedException{
		//No race condition local variables always thread safe
		//See: http://stackoverflow.com/questions/12825847/why-are-local-variables-thread-safe-in-java
		int i = 0;
		for(int x = 0; x < 1000; x++){
			i = i + 1;
		}
		System.out.println(i);
	}
	
	public static void main(String[] args) {
		ThreadSafety r1 = new ThreadSafety();
		ThreadSafety r2 = new ThreadSafety();
		new Thread(r1).start();
		new Thread(r2).start();
	}
}