1 /* 2 * Copyright (C) 2018 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 import java.util.concurrent.CountDownLatch; 18 19 interface I { 20 } 21 22 class A implements I { 23 static int x = (int)(10*Math.random()); // Suppress compile-time initialization. 24 } 25 26 public class Main { main(String[] args)27 public static void main(String[] args) throws Exception { 28 final CountDownLatch first = new CountDownLatch(1); 29 final CountDownLatch second = new CountDownLatch(1); 30 31 new Thread(new Runnable() { 32 public void run() { 33 try { 34 synchronized(I.class) { 35 first.countDown(); 36 second.await(); 37 } 38 } catch (Exception e) { 39 e.printStackTrace(); 40 } 41 } 42 }).start(); 43 44 first.await(); 45 new A(); // Will initialize A. 46 second.countDown(); 47 48 System.out.println("Done."); 49 } 50 } 51