/*
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* Copyright (C) 2016 The Android Open Source Project
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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public class RacyMisbehavingLoader extends DefiningLoader {
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static {
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// For JVM, register as parallel capable.
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// Android treats all class loaders as parallel capable and makes this a no-op.
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registerAsParallelCapable();
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}
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private Object lock = new Object();
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private int index = 0;
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private int count;
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private boolean throw_error;
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private DefiningLoader[] defining_loaders;
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public RacyMisbehavingLoader(ClassLoader parent, int count, boolean throw_error) {
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super(parent);
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this.count = count;
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this.throw_error = throw_error;
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defining_loaders = new DefiningLoader[2];
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for (int i = 0; i != defining_loaders.length; ++i) {
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defining_loaders[i] = new DefiningLoader(parent);
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}
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}
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public void reportAfterLoading() {
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synchronized (lock) {
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++index;
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if (index == 2 * count) {
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lock.notifyAll();
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}
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}
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}
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protected Class<?> findClass(String name) throws ClassNotFoundException
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{
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if (name.equals("Test")) {
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throw new Error("Unexpected RacyLoader.findClass(\"" + name + "\")");
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}
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return super.findClass(name);
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}
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protected Class<?> loadClass(String name, boolean resolve)
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throws ClassNotFoundException
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{
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if (name.equals("Test")) {
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int my_index = syncWithOtherInstances(count);
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Class<?> result;
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if ((my_index & 1) == 0) {
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// Do not delay loading the correct class.
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result = defining_loaders[my_index & 1].loadClass(name, resolve);
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} else {
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// Delay loading the wrong class.
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syncWithOtherInstances(2 * count);
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if (throw_error) {
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throw new Error("RacyMisbehavingLoader throw_error=true");
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}
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result = defining_loaders[my_index & 1].loadClass("Test3", resolve);
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}
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return result;
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}
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return super.loadClass(name, resolve);
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}
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private int syncWithOtherInstances(int limit) {
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int my_index;
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synchronized (lock) {
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my_index = index;
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++index;
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if (index != limit) {
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do {
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try {
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lock.wait();
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} catch (InterruptedException ie) {
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throw new Error(ie);
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}
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} while (index < limit);
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} else {
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lock.notifyAll();
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}
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}
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return my_index;
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}
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}
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