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 }