private void resize(int depth, HashMap<K,V>[] oldTab){
		synchronized(lock[depth]){
			if (oldTab == table){
				int next = depth + 1;
				if (next < lock.length){
					resize (next, oldTab);
				}
				else{
					System.out.println("resize start");
					long start = System.currentTimeMillis();
					sequentialResize();
					System.out.println("resize end for " + (System.currentTimeMillis() - start));
				}
			}
		}
	}