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/*
* Copyright (c) 2018, 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.io.IOException;
import java.lang.reflect.*;
import java.net.URL;
import java.net.URLConnection;
import java.net.URLStreamHandler;
import java.util.concurrent.CountDownLatch;
/*
* @test
* @bug 8213942
* @summary URLStreamHandler initialization race
* @run main/othervm RacyHandler
* @run main/othervm RacyHandler
* @run main/othervm RacyHandler
*/
/*
* This test makes reasonable effort to reproduce the race.
* Run repeatedly to ensure correctness.
*/
public class RacyHandler {
static volatile boolean factorySet = false;
static int NUM_THREADS = 2;
static CountDownLatch cdl = new CountDownLatch(NUM_THREADS + 1);
public static void main(String[] args) {
RacyHandler tester = new RacyHandler();
tester.runTest();
}
public void runTest() {
new Thread(() -> {
try {
cdl.await();
URL.setURLStreamHandlerFactory(proto -> new CustomHttpHandler());
factorySet = true;
} catch (Exception ignore) { }
}).start();
cdl.countDown();
for (int i = 0; i < NUM_THREADS; i++) {
new Thread(() -> {
try {
cdl.await();
while (!factorySet) {
// trigger URL class load
getURLStreamHandler();
}
} catch (Exception ignore) { }
}).start();
cdl.countDown();
}
// wait for the factory to be set
while (!factorySet) { }
// The sleep seems to help trigger the failure
try {
Thread.sleep(500);
} catch (InterruptedException ie) {
}
URLStreamHandler httpHandler = getURLStreamHandler();
System.out.println("After setting factory URL handlers: http " + httpHandler);
if (!(httpHandler instanceof CustomHttpHandler))
throw new RuntimeException("FAILED: Incorrect handler type");
}
/*
* This is just so we can see what we get for the URLStreamHandler back
* from the factory to verify whether it really is using our Handler
* or something else...
*/
public URLStreamHandler getURLStreamHandler() {
try {
Method method = URL.class.getDeclaredMethod("getURLStreamHandler",
String.class);
method.setAccessible(true);
return (URLStreamHandler) method.invoke(null, "http");
} catch (Exception e) {
return null;
}
}
class CustomHttpHandler extends URLStreamHandler {
@Override
protected URLConnection openConnection(URL u) throws IOException {
return null;
}
}
}
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