why not n == 10

IndexPlusPlusTest.java

package concurrent;

import java.util.concurrent.atomic.AtomicInteger;

/**
 * Created by magicalli on 2014/12/13.
 */
public class IndexPlusPlusTest {
    private volatile static int n = 0;
    private static int m = 0;
    private volatile static AtomicInteger atomicInteger = new AtomicInteger(0);

    public static void main(String[] args) {

        for (int i = 0; i < 10; i++) {
            new Thread(new Runnable() {
                @Override
                public void run() {
//                    synchronized (IndexPlusPlusTest.class) {
//                    atomicInteger.addAndGet(1);
                    synchronized (IndexPlusPlusTest.class) {//因为已经有thread开始了,所以同步没用???
                        n++;
                    }
                }
            }).start();
        }

//        ExecutorService pool = Executors.newCachedThreadPool();
//        for (int i = 0; i < 10; i++) {
//            pool.submit(new Runnable() {
//                @Override
//                public void run() {
//                    m++;
//                }
//            });
//        }
        System.out.println("n:" + n);
        System.out.println("m:" + m);
        System.out.println("atomicInteger:" + atomicInteger);
    }
}

额，犯傻了，因为Thread还没有执行完成， System.out.println("n:" + n);就先执行了