1 /* 2 * Copyright (c) 2012, 2020, 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 package sun.jvm.hotspot.classfile; 26 27 import sun.jvm.hotspot.debugger.*; 28 import sun.jvm.hotspot.memory.*; 29 import sun.jvm.hotspot.runtime.*; 30 import sun.jvm.hotspot.oops.*; 31 import sun.jvm.hotspot.types.*; 32 33 public class ClassLoaderData extends VMObject { 34 static { 35 VM.registerVMInitializedObserver(new java.util.Observer() { 36 public void update(java.util.Observable o, Object data) { 37 initialize(VM.getVM().getTypeDataBase()); 38 } 39 }); 40 } 41 42 private static synchronized void initialize(TypeDataBase db) throws WrongTypeException { 43 Type type = db.lookupType("ClassLoaderData"); 44 classLoaderFieldOffset = type.getAddressField("_class_loader").getOffset(); 45 nextField = type.getAddressField("_next"); 46 klassesField = new MetadataField(type.getAddressField("_klasses"), 0); 47 dictionaryField = type.getAddressField("_dictionary"); 48 } 49 50 private static long classLoaderFieldOffset; 51 private static AddressField nextField; 52 private static MetadataField klassesField; 53 private static AddressField dictionaryField; 54 55 public ClassLoaderData(Address addr) { 56 super(addr); 57 } 58 59 public Dictionary dictionary() { 60 Address tmp = dictionaryField.getValue(); 61 return (Dictionary) VMObjectFactory.newObject(Dictionary.class, tmp); 62 } 63 64 public static ClassLoaderData instantiateWrapperFor(Address addr) { 65 if (addr == null) { 66 return null; 67 } 68 return new ClassLoaderData(addr); 69 } 70 71 public Oop getClassLoader() { 72 Address addr = getAddress().addOffsetTo(classLoaderFieldOffset); 73 VMOopHandle vmOopHandle = VMObjectFactory.newObject(VMOopHandle.class, addr); 74 return vmOopHandle.resolve(); 75 } 76 77 public ClassLoaderData next() { 78 return instantiateWrapperFor(nextField.getValue(getAddress())); 79 } 80 81 public Klass getKlasses() { return (Klass)klassesField.getValue(this); } 82 83 /** Lookup an already loaded class. If not found null is returned. */ 84 public Klass find(String className) { 85 for (Klass l = getKlasses(); l != null; l = l.getNextLinkKlass()) { 86 if (l.getName().equals(className)) { 87 return l; 88 } 89 } 90 return null; 91 } 92 93 /** Iterate over all klasses - including object, primitive 94 array klasses */ 95 public void classesDo(ClassLoaderDataGraph.ClassVisitor v) { 96 for (Klass l = getKlasses(); l != null; l = l.getNextLinkKlass()) { 97 v.visit(l); 98 } 99 } 100 101 /** Iterate over all klasses in the dictionary, including initiating loader. */ 102 public void allEntriesDo(ClassLoaderDataGraph.ClassAndLoaderVisitor v) { 103 for (Klass l = getKlasses(); l != null; l = l.getNextLinkKlass()) { 104 dictionary().allEntriesDo(v, getClassLoader()); 105 } 106 } 107 }