1 /*
   2  * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  */
  23 
  24 import java.io.IOException;
  25 import java.lang.reflect.*;
  26 import java.net.URL;
  27 import java.net.URLConnection;
  28 import java.net.URLStreamHandler;
  29 import java.util.concurrent.CountDownLatch;
  30 
  31 /*
  32  * @test
  33  * @bug 8213942
  34  * @summary URLStreamHandler initialization race

  35  * @run main/othervm RacyHandler
  36  * @run main/othervm RacyHandler
  37  * @run main/othervm RacyHandler
  38  */
  39 
  40 /*
  41  * This test makes reasonable effort to reproduce the race.
  42  * Run repeatedly to ensure correctness.
  43  */
  44 public class RacyHandler {
  45     static volatile boolean factorySet = false;
  46     static int NUM_THREADS = 2;
  47     static CountDownLatch cdl = new CountDownLatch(NUM_THREADS + 1);
  48 
  49     public static void main(String[] args) {
  50         RacyHandler tester = new RacyHandler();
  51         tester.runTest();
  52     }
  53 
  54     public void runTest() {
  55         new Thread(() -> {
  56             try {
  57                 cdl.await();
  58                 URL.setURLStreamHandlerFactory(proto -> new CustomHttpHandler());
  59                 factorySet = true;
  60             } catch (Exception ignore) { }
  61         }).start();
  62         cdl.countDown();
  63 
  64         for (int i = 0; i < NUM_THREADS; i++) {
  65             new Thread(() -> {
  66                 try {
  67                     cdl.await();
  68                     while (!factorySet) {
  69                         // trigger URL class load
  70                         getURLStreamHandler();
  71                     }
  72                 } catch (Exception ignore) { }
  73             }).start();
  74             cdl.countDown();
  75         }
  76 
  77         // wait for the factory to be set
  78         while (!factorySet) { }
  79         // The sleep seems to help trigger the failure
  80         try {
  81             Thread.sleep(500);
  82         } catch (InterruptedException ie) {
  83         }
  84 
  85         URLStreamHandler httpHandler = getURLStreamHandler();
  86         System.out.println("After setting factory URL handlers: http " + httpHandler);
  87         if (!(httpHandler instanceof CustomHttpHandler))
  88             throw new RuntimeException("FAILED: Incorrect handler type");
  89     }
  90 
  91     /*
  92      * This is just so we can see what we get for the URLStreamHandler back
  93      * from the factory to verify whether it really is using our Handler
  94      * or something else...
  95      */
  96     public URLStreamHandler getURLStreamHandler() {
  97         try {
  98             Method method = URL.class.getDeclaredMethod("getURLStreamHandler",
  99                     String.class);
 100             method.setAccessible(true);
 101             return (URLStreamHandler) method.invoke(null, "http");
 102         } catch (Exception e) {
 103             return null;
 104         }
 105     }
 106 
 107     class CustomHttpHandler extends URLStreamHandler {
 108         @Override
 109         protected URLConnection openConnection(URL u) throws IOException {
 110             return null;
 111         }
 112     }
 113 }
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