1 /* 2 * Copyright (c) 2013, 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 G1AddMetaspaceDependency 26 * @bug 8010196 27 * @requires vm.gc=="G1" | vm.gc=="null" 28 * @summary Checks that we don't get locking problems when adding metaspace dependencies with the G1 update buffer monitor 29 * @run main/othervm -XX:+UseG1GC -XX:G1UpdateBufferSize=1 G1AddMetaspaceDependency 30 */ 31 32 import java.io.InputStream; 33 34 public class G1AddMetaspaceDependency { 35 36 static byte[] getClassBytes(String name) { 37 byte[] b = null; 38 try (InputStream is = ClassLoader.getSystemResourceAsStream(name)) { 39 byte[] tmp = new byte[is.available()]; 40 is.read(tmp); 41 b = tmp; 42 } finally { 43 if (b == null) { 44 throw new RuntimeException("Unable to load class file"); 45 } 46 return b; 47 } 48 } 49 50 static final String a_name = G1AddMetaspaceDependency.class.getName() + "$A"; 51 static final String b_name = G1AddMetaspaceDependency.class.getName() + "$B"; 52 53 public static void main(String... args) throws Exception { 54 final byte[] a_bytes = getClassBytes(a_name + ".class"); 55 final byte[] b_bytes = getClassBytes(b_name + ".class"); 56 57 for (int i = 0; i < 1000; i += 1) { 58 runTest(a_bytes, b_bytes); 59 } 60 } 61 62 static class Loader extends ClassLoader { 63 private final String myClass; 64 private final byte[] myBytes; 65 private final String friendClass; 66 private final ClassLoader friendLoader; 67 68 Loader(String myClass, byte[] myBytes, 69 String friendClass, ClassLoader friendLoader) { 70 this.myClass = myClass; 71 this.myBytes = myBytes; 72 this.friendClass = friendClass; 73 this.friendLoader = friendLoader; 74 } 75 76 Loader(String myClass, byte[] myBytes) { 77 this(myClass, myBytes, null, null); 78 } 79 80 @Override 81 public Class<?> loadClass(String name) throws ClassNotFoundException { 82 Class<?> c = findLoadedClass(name); 83 if (c != null) { 84 return c; 85 } 86 87 if (name.equals(friendClass)) { 88 return friendLoader.loadClass(name); 89 } 90 91 if (name.equals(myClass)) { 92 c = defineClass(name, myBytes, 0, myBytes.length); 93 resolveClass(c); 94 return c; 95 } 96 97 return findSystemClass(name); 98 } 99 100 } 101 102 private static void runTest(final byte[] a_bytes, final byte[] b_bytes) throws Exception { 103 Loader a_loader = new Loader(a_name, a_bytes); 104 Loader b_loader = new Loader(b_name, b_bytes, a_name, a_loader); 105 Loader c_loader = new Loader(b_name, b_bytes, a_name, a_loader); 106 Loader d_loader = new Loader(b_name, b_bytes, a_name, a_loader); 107 Loader e_loader = new Loader(b_name, b_bytes, a_name, a_loader); 108 Loader f_loader = new Loader(b_name, b_bytes, a_name, a_loader); 109 Loader g_loader = new Loader(b_name, b_bytes, a_name, a_loader); 110 111 Class<?> c; 112 c = b_loader.loadClass(b_name); 113 c = c_loader.loadClass(b_name); 114 c = d_loader.loadClass(b_name); 115 c = e_loader.loadClass(b_name); 116 c = f_loader.loadClass(b_name); 117 c = g_loader.loadClass(b_name); 118 } 119 public class A { 120 } 121 class B extends A { 122 } 123 }