1 /* 2 * Copyright (c) 2010, 2016 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.util.Properties; 25 import java.util.concurrent.CyclicBarrier; 26 import java.util.concurrent.BrokenBarrierException; 27 import java.io.IOException; 28 import java.net.URL; 29 30 /* @test 31 * @bug 6977738 8029891 32 * @summary Test ClassLoader.getResource() that should not deadlock 33 # if another thread is holding the system properties object 34 * 35 * @build GetResource 36 * @run main GetResource 37 */ 38 39 public class GetResource { 40 CyclicBarrier go = new CyclicBarrier(2); 41 CyclicBarrier done = new CyclicBarrier(2); 42 Thread t1, t2; 43 public GetResource() { 44 t1 = new Thread() { 45 public void run() { 46 Properties prop = System.getProperties(); 47 synchronized (prop) { 48 System.out.println("Thread 1 ready"); 49 try { 50 go.await(); 51 prop.put("property", "value"); 52 prop.store(System.out, ""); 53 done.await(); // keep holding the lock until t2 finishes 54 } catch (InterruptedException e) { 55 throw new RuntimeException(e); 56 } catch (BrokenBarrierException e) { 57 throw new RuntimeException(e); 58 } catch (IOException e) { 59 throw new RuntimeException(e); 60 } 61 } 62 System.out.println("Thread 1 exits"); 63 } 64 }; 65 66 t2 = new Thread() { 67 public void run() { 68 System.out.println("Thread 2 ready"); 69 try { 70 go.await(); // wait until t1 holds the lock of the system properties 71 72 URL u1 = Thread.currentThread().getContextClassLoader().getResource("unknownresource"); 73 done.await(); 74 } catch (InterruptedException e) { 75 throw new RuntimeException(e); 76 } catch (BrokenBarrierException e) { 77 throw new RuntimeException(e); 78 } 79 System.out.println("Thread 2 exits"); 80 } 81 }; 82 } 83 84 public void run() throws Exception { 85 t1.start(); 86 t2.start(); 87 try { 88 t1.join(); 89 } catch (InterruptedException e) { 90 e.printStackTrace(); 91 throw e; 92 } 93 try { 94 t2.join(); 95 } catch (InterruptedException e) { 96 e.printStackTrace(); 97 throw e; 98 } 99 } 100 101 public static void main(String[] args) throws Exception { 102 new GetResource().run(); 103 } 104 }