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