[Java] 关于synchronized有趣的同步问题

public class syncthreadtest extends thread {
  public static integer count = 0;
  private static final int times = 10000;
  public syncthreadtest(){
  super("syncthread");
  }
  @override
  public void run(){
  synchronized (count){
    for (int i = 0; i < times; i ++){
    count++;
    }
  }
  }
  public static void main(string[] args) throws interruptedexception{
  syncthreadtest t1 = new syncthreadtest();
  syncthreadtest t2 = new syncthreadtest();
  t1.start();
  t2.start();
  t1.join();
  t2.join();
  system.out.println(count);
  }
}