1 /* 2 * Copyright (c) 2013, 2019, 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 package gc.metaspace; 25 26 /* 27 * @test G1AddMetaspaceDependency 28 * @bug 8010196 29 * @requires vm.gc.G1 30 * @library / 31 * @summary Checks that we don't get locking problems when adding metaspace dependencies with the G1 update buffer monitor 32 * @run main/othervm -XX:+UseG1GC -XX:G1UpdateBufferSize=1 gc.metaspace.G1AddMetaspaceDependency 33 */ 34 35 import java.io.InputStream; 36 37 public class G1AddMetaspaceDependency { 38 getClassBytes(String name)39 static byte[] getClassBytes(String name) { 40 byte[] b = null; 41 try (InputStream is = ClassLoader.getSystemResourceAsStream(name)) { 42 byte[] tmp = new byte[is.available()]; 43 is.read(tmp); 44 b = tmp; 45 } finally { 46 if (b == null) { 47 throw new RuntimeException("Unable to load class file"); 48 } 49 return b; 50 } 51 } 52 53 static final String a_name = A.class.getName(); 54 static final String b_name = B.class.getName(); 55 main(String... args)56 public static void main(String... args) throws Exception { 57 final byte[] a_bytes = getClassBytes(a_name.replace('.', '/') + ".class"); 58 final byte[] b_bytes = getClassBytes(b_name.replace('.', '/') + ".class"); 59 60 for (int i = 0; i < 1000; i += 1) { 61 runTest(a_bytes, b_bytes); 62 } 63 } 64 65 static class Loader extends ClassLoader { 66 private final String myClass; 67 private final byte[] myBytes; 68 private final String friendClass; 69 private final ClassLoader friendLoader; 70 Loader(String myClass, byte[] myBytes, String friendClass, ClassLoader friendLoader)71 Loader(String myClass, byte[] myBytes, 72 String friendClass, ClassLoader friendLoader) { 73 this.myClass = myClass; 74 this.myBytes = myBytes; 75 this.friendClass = friendClass; 76 this.friendLoader = friendLoader; 77 } 78 Loader(String myClass, byte[] myBytes)79 Loader(String myClass, byte[] myBytes) { 80 this(myClass, myBytes, null, null); 81 } 82 83 @Override loadClass(String name)84 public Class<?> loadClass(String name) throws ClassNotFoundException { 85 Class<?> c = findLoadedClass(name); 86 if (c != null) { 87 return c; 88 } 89 90 if (name.equals(friendClass)) { 91 return friendLoader.loadClass(name); 92 } 93 94 if (name.equals(myClass)) { 95 c = defineClass(name, myBytes, 0, myBytes.length); 96 resolveClass(c); 97 return c; 98 } 99 100 return findSystemClass(name); 101 } 102 103 } 104 runTest(final byte[] a_bytes, final byte[] b_bytes)105 private static void runTest(final byte[] a_bytes, final byte[] b_bytes) throws Exception { 106 Loader a_loader = new Loader(a_name, a_bytes); 107 Loader b_loader = new Loader(b_name, b_bytes, a_name, a_loader); 108 Loader c_loader = new Loader(b_name, b_bytes, a_name, a_loader); 109 Loader d_loader = new Loader(b_name, b_bytes, a_name, a_loader); 110 Loader e_loader = new Loader(b_name, b_bytes, a_name, a_loader); 111 Loader f_loader = new Loader(b_name, b_bytes, a_name, a_loader); 112 Loader g_loader = new Loader(b_name, b_bytes, a_name, a_loader); 113 114 b_loader.loadClass(b_name); 115 c_loader.loadClass(b_name); 116 d_loader.loadClass(b_name); 117 e_loader.loadClass(b_name); 118 f_loader.loadClass(b_name); 119 g_loader.loadClass(b_name); 120 } 121 public class A { 122 } 123 class B extends A { 124 } 125 } 126