1 /* 2 * Copyright (c) 2014, 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 TestDeferredRSUpdate 26 * @bug 8040977 27 * @summary Ensure that running with -XX:-G1DeferredRSUpdate does not crash the VM 28 * @key gc 29 * @library /testlibrary 30 */ 31 32 import com.oracle.java.testlibrary.ProcessTools; 33 import com.oracle.java.testlibrary.OutputAnalyzer; 34 35 public class TestDeferredRSUpdate { 36 public static void main(String[] args) throws Exception { 37 GCTest.main(args); 38 39 ProcessBuilder pb = ProcessTools.createJavaProcessBuilder("-XX:+UseG1GC", 40 "-Xmx10M", 41 // G1DeferredRSUpdate is a develop option, but we cannot limit execution of this test to only debug VMs. 42 "-XX:+IgnoreUnrecognizedVMOptions", 43 "-XX:-G1DeferredRSUpdate", 44 GCTest.class.getName()); 45 46 OutputAnalyzer output = new OutputAnalyzer(pb.start()); 47 output.shouldHaveExitValue(0); 48 } 49 50 static class GCTest { 51 private static Object[] garbage = new Object[32]; 52 53 public static void main(String [] args) { 54 System.out.println("Creating garbage"); 55 // Create 128MB of garbage. This should result in at least one minor GC, with 56 // some objects copied to old gen. As references from old to young are installed, 57 // the crash due to the use before initialize occurs. 58 Object prev = null; 59 Object prevPrev = null; 60 for (int i = 0; i < 1024; i++) { 61 Object[] next = new Object[32 * 1024]; 62 next[0] = prev; 63 next[1] = prevPrev; 64 65 Object[] cur = (Object[]) garbage[i % garbage.length]; 66 if (cur != null) { 67 cur[0] = null; 68 cur[1] = null; 69 } 70 garbage[i % garbage.length] = next; 71 72 prevPrev = prev; 73 prev = next; 74 } 75 System.out.println("Done"); 76 } 77 } 78 }