--- /dev/null Fri Jun 23 16:46:51 2017 +++ new/test/java/net/NetworkInterface/GetMacAddress.java Fri Jun 23 16:46:51 2017 @@ -0,0 +1,131 @@ +/* + * Copyright (c) 2017, 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. + */ + +/* + * @test + * @bug 8182672 + * @summary Java 8u121 on Linux intermittently returns null for MAC address + */ + +import java.net.NetworkInterface; +import java.util.ArrayList; +import java.util.List; +import java.util.concurrent.Callable; +import java.util.concurrent.ExecutorService; +import java.util.concurrent.Executors; +import java.util.concurrent.Future; +import java.util.concurrent.Phaser; +import java.util.function.Predicate; +import java.util.stream.Collectors; +import java.util.stream.Stream; + +public class GetMacAddress implements Callable { + static final int NUM_THREADS = 5; + static final int NUM_ITERS = 100; + static volatile boolean failed; // false + + final String threadName; + final NetworkInterface ni; + final Phaser startingGate; + + public GetMacAddress(NetworkInterface ni, String name, Phaser phaser) { + this.ni = ni; + this.threadName = name; + this.startingGate = phaser; + } + + @Override + public Exception call() { + int count = 0; + startingGate.arriveAndAwaitAdvance(); + try { + for (int i = 0; i < NUM_ITERS; i++) { + ni.getMTU(); + byte[] addr = ni.getHardwareAddress(); + if (addr == null) { + System.out.println(threadName + ". mac id is null"); + failed = true; + } + count = count + 1; + if (count % 100 == 0) { + System.out.println(threadName + ". count is " + count); + } + } + } catch (Exception ex) { + System.out.println(threadName + ". Not expecting exception:" + ex.getMessage()); + failed = true; + return ex; + } + return null; + } + + static final Predicate hasHardwareAddress = ni -> { + try { + if (ni.getHardwareAddress() == null) { + System.out.println("Not testing null addr: " + ni.getName()); + return false; + } + } catch (Exception ex) { + System.out.println("Not testing: " + ni.getName() + + " " + ex.getMessage()); + return false; + } + return true; + }; + + public static Stream getNetworkInterfacesAsStream() throws Exception { + // JDK 9 and later + return NetworkInterface.networkInterfaces(); + // pre JDK 9 + //return Collections.list(NetworkInterface.getNetworkInterfaces()).stream(); + } + + public static void main(String[] args) throws Exception { + List toTest = getNetworkInterfacesAsStream() + .filter(hasHardwareAddress) + .collect(Collectors.toList()); + + ExecutorService executor = Executors.newFixedThreadPool(NUM_THREADS); + + for (NetworkInterface ni : toTest) { + Phaser startingGate = new Phaser(NUM_THREADS); + System.out.println("Testing: " + ni.getName()); + List> list = new ArrayList<>(); + for (int i = 0; i < NUM_THREADS; i++) + list.add(new GetMacAddress(ni, ni.getName() + "-Thread-" + i, startingGate)); + List> futures = executor.invokeAll(list); + for (Future f : futures) { + if (f.get() != null) + f.get().printStackTrace(System.out); + } + if (failed) + break; + } + executor.shutdownNow(); + if (!failed) { + System.out.println("PASSED - Finished all threads"); + } else { + throw new RuntimeException("Failed"); + } + } +}