1 /*
   2  * Copyright (c) 2017, 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 /*
  25  * @test
  26  * @bug 8182672
  27  * @summary Java 8u121 on Linux intermittently returns null for MAC address
  28  */
  29 
  30 import java.net.NetworkInterface;
  31 import java.util.ArrayList;
  32 import java.util.List;
  33 import java.util.concurrent.Callable;
  34 import java.util.concurrent.ExecutorService;
  35 import java.util.concurrent.Executors;
  36 import java.util.concurrent.Future;
  37 import java.util.concurrent.Phaser;
  38 import java.util.function.Predicate;
  39 import java.util.stream.Collectors;
  40 import java.util.stream.Stream;
  41 
  42 public class GetMacAddress implements Callable<Exception> {
  43     static final int NUM_THREADS = 5;
  44     static final int NUM_ITERS = 100;
  45     static volatile boolean failed; // false
  46 
  47     final String threadName;
  48     final NetworkInterface ni;
  49     final Phaser startingGate;
  50 
  51     public GetMacAddress(NetworkInterface ni, String name, Phaser phaser) {
  52         this.ni = ni;
  53         this.threadName = name;
  54         this.startingGate = phaser;
  55     }
  56 
  57     @Override
  58     public Exception call() {
  59         int count = 0;
  60         startingGate.arriveAndAwaitAdvance();
  61         try {
  62             for (int i = 0; i < NUM_ITERS; i++) {
  63                 ni.getMTU();
  64                 byte[] addr = ni.getHardwareAddress();
  65                 if (addr == null) {
  66                     System.out.println(threadName + ". mac id is null");
  67                     failed = true;
  68                 }
  69                 count = count + 1;
  70                 if (count % 100 == 0) {
  71                     System.out.println(threadName + ". count is " + count);
  72                 }
  73             }
  74         } catch (Exception ex) {
  75             System.out.println(threadName + ". Not expecting exception:" + ex.getMessage());
  76             failed = true;
  77             return ex;
  78         }
  79         return null;
  80     }
  81 
  82     static final Predicate<NetworkInterface> hasHardwareAddress = ni -> {
  83         try {
  84             if (ni.getHardwareAddress() == null) {
  85                 System.out.println("Not testing null addr: " + ni.getName());
  86                 return false;
  87             }
  88         } catch (Exception ex) {
  89             System.out.println("Not testing: " + ni.getName() +
  90                     " " + ex.getMessage());
  91             return false;
  92         }
  93         return true;
  94     };
  95 
  96     public static Stream<NetworkInterface> getNetworkInterfacesAsStream() throws Exception {
  97         // JDK 9 and later
  98         return NetworkInterface.networkInterfaces();
  99         // pre JDK 9
 100         //return Collections.list(NetworkInterface.getNetworkInterfaces()).stream();
 101     }
 102 
 103     public static void main(String[] args) throws Exception {
 104         List<NetworkInterface> toTest = getNetworkInterfacesAsStream()
 105                         .filter(hasHardwareAddress)
 106                         .collect(Collectors.toList());
 107 
 108         ExecutorService executor = Executors.newFixedThreadPool(NUM_THREADS);
 109 
 110         for (NetworkInterface ni : toTest) {
 111             Phaser startingGate = new Phaser(NUM_THREADS);
 112             System.out.println("Testing: " + ni.getName());
 113             List<Callable<Exception>> list = new ArrayList<>();
 114             for (int i = 0; i < NUM_THREADS; i++)
 115                 list.add(new GetMacAddress(ni, ni.getName() + "-Thread-" + i, startingGate));
 116             List<Future<Exception>> futures = executor.invokeAll(list);
 117             for (Future<Exception> f : futures) {
 118                 if (f.get() != null)
 119                     f.get().printStackTrace(System.out);
 120             }
 121             if (failed)
 122                 break;
 123         }
 124         executor.shutdownNow();
 125         if (!failed) {
 126             System.out.println("PASSED - Finished all threads");
 127         } else {
 128             throw new RuntimeException("Failed");
 129         }
 130     }
 131 }