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  * @modules java.base/java.net:open
  36  * @run main/othervm RacyHandler
  37  * @run main/othervm RacyHandler
  38  * @run main/othervm RacyHandler
  39  */
  40 
  41 /*
  42  * This test makes reasonable effort to reproduce the race.
  43  * Run repeatedly to ensure correctness.
  44  */
  45 public class RacyHandler {
  46     static volatile boolean factorySet = false;
  47     static int NUM_THREADS = 2;
  48     static CountDownLatch cdl = new CountDownLatch(NUM_THREADS + 1);
  49 
  50     public static void main(String[] args) {
  51         RacyHandler tester = new RacyHandler();
  52         tester.runTest();
  53     }
  54 
  55     public void runTest() {
  56         new Thread(() -> {
  57             try {
  58                 cdl.await();
  59                 URL.setURLStreamHandlerFactory(proto -> new CustomHttpHandler());
  60                 factorySet = true;
  61             } catch (Exception ignore) { }
  62         }).start();
  63         cdl.countDown();
  64 
  65         for (int i = 0; i < NUM_THREADS; i++) {
  66             new Thread(() -> {
  67                 try {
  68                     cdl.await();
  69                     while (!factorySet) {
  70                         // trigger URL class load
  71                         getURLStreamHandler();
  72                     }
  73                 } catch (Exception ignore) { }
  74             }).start();
  75             cdl.countDown();
  76         }
  77 
  78         // wait for the factory to be set
  79         while (!factorySet) { }
  80         // The sleep seems to help trigger the failure
  81         try {
  82             Thread.sleep(500);
  83         } catch (InterruptedException ie) {
  84         }
  85 
  86         URLStreamHandler httpHandler = getURLStreamHandler();
  87         System.out.println("After setting factory URL handlers: http " + httpHandler);
  88         if (!(httpHandler instanceof CustomHttpHandler))
  89             throw new RuntimeException("FAILED: Incorrect handler type");
  90     }
  91 
  92     /*
  93      * This is just so we can see what we get for the URLStreamHandler back
  94      * from the factory to verify whether it really is using our Handler
  95      * or something else...
  96      */
  97     public URLStreamHandler getURLStreamHandler() {
  98         try {
  99             Method method = URL.class.getDeclaredMethod("getURLStreamHandler",
 100                     String.class);
 101             method.setAccessible(true);
 102             return (URLStreamHandler) method.invoke(null, "http");
 103         } catch (Exception e) {
 104             return null;
 105         }
 106     }
 107 
 108     class CustomHttpHandler extends URLStreamHandler {
 109         @Override
 110         protected URLConnection openConnection(URL u) throws IOException {
 111             return null;
 112         }
 113     }
 114 }