asynctask wait all finish

gistfile1.txt

CountDownLatch cdl = new CountDownLatch(2);
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        try {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
            new TestTask(cdl).execute();
            new TestTask(cdl).execute();
            cdl.await();
            Log.i("vin","stop");
        } catch (Exception e) {
            Log.i("vin", e.toString());
        }
    }

    private class TestTask extends AsyncTask<Void,Void,Void> {
        private CountDownLatch mCdl;
        public TestTask(CountDownLatch cdl) {
            super();
            mCdl = cdl;
        }

        @Override
        protected Void doInBackground(Void... voids) {
            try {
                Thread.sleep(10);
            } catch (Exception e) {

            }
            return null;
        }

        @Override
        protected void onPostExecute(Void aVoid) {
            super.onPostExecute(aVoid);
            mCdl.countDown();
            Log.i("vin", "onPostExecute");
        }
    }