Mercurial > hg > icedtea7-forest > jdk
view test/java/lang/reflect/Proxy/ProxyRace.java @ 9225:8f1c0d565d13
8174729: Race Condition in java.lang.reflect.WeakCache
Summary: Race can occur between Proxy.getProxyClass and Proxy.isProxyClass
Reviewed-by: mchung
author | adinn |
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date | Sat, 15 Jul 2017 21:26:47 +0100 |
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/* * Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ import java.lang.reflect.Proxy; import java.util.concurrent.ExecutorService; import java.util.concurrent.Executors; import java.util.concurrent.Phaser; import java.util.concurrent.TimeUnit; import java.util.concurrent.atomic.AtomicInteger; /** * @test * @bug 8174729 * @summary Proxy.getProxyClass() / Proxy.isProxyClass() race detector * @run main ProxyRace * @author plevart */ public class ProxyRace { static final int threads = 8; static volatile ClassLoader classLoader; static volatile boolean terminate; static final AtomicInteger racesDetected = new AtomicInteger(); public static void main(String[] args) throws Exception { final Phaser phaser = new Phaser(threads) { @Override protected boolean onAdvance(int phase, int registeredParties) { // install new ClassLoader on each advance classLoader = new CL(); return terminate; } }; ExecutorService exe = Executors.newFixedThreadPool(threads); for (int i = 0; i < threads; i++) { exe.execute(new Runnable() { @Override public void run() { while (phaser.arriveAndAwaitAdvance() >= 0) { Class<?> proxyClass = Proxy.getProxyClass(classLoader, Runnable.class); if (!Proxy.isProxyClass(proxyClass)) { racesDetected.incrementAndGet(); } } } }); } Thread.sleep(5000L); terminate = true; exe.shutdown(); exe.awaitTermination(5L, TimeUnit.SECONDS); System.out.println(racesDetected.get() + " races detected"); if (racesDetected.get() != 0) { throw new RuntimeException(racesDetected.get() + " races detected"); } } static class CL extends ClassLoader { public CL() { super(ClassLoader.getSystemClassLoader()); } } }