/* * Copyright 2019 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ class Main { private static final boolean DEBUG = false; public static void main(String[] args) throws Exception { System.loadLibrary(args[0]); makeVisiblyInitialized(); Class testClass = Class.forName("TestClass"); // Request initialized class. boolean is_visibly_initialized = isVisiblyInitialized(testClass); if (DEBUG) { System.out.println((is_visibly_initialized ? "Already" : "Not yet") + " visibly intialized"); } if (!is_visibly_initialized) { synchronized(testClass) { Thread t = new Thread() { public void run() { // Regression test: This would have previously deadlocked // trying to lock on testClass. b/138561860 makeVisiblyInitialized(); } }; t.start(); t.join(); } if (!isVisiblyInitialized(testClass)) { throw new Error("Should be visibly initialized now."); } } } public static native void makeVisiblyInitialized(); public static native boolean isVisiblyInitialized(Class klass); } class TestClass { static { // Add a static constructor that prevents initialization at compile time (app images). Main.isVisiblyInitialized(TestClass.class); // Native call, discard result. } }