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 import sun.jvm.hotspot.utilities.Observable; 33 import sun.jvm.hotspot.utilities.Observer; 34 35 public class ClassLoaderData extends VMObject { 36 static { 37 VM.registerVMInitializedObserver(new Observer() { 38 public void update(Observable o, Object data) { 39 initialize(VM.getVM().getTypeDataBase()); 40 } 41 }); 42 } 43 44 private static synchronized void initialize(TypeDataBase db) throws WrongTypeException { 45 Type type = db.lookupType("ClassLoaderData"); 46 classLoaderFieldOffset = type.getAddressField("_class_loader").getOffset(); 47 nextField = type.getAddressField("_next"); 48 klassesField = new MetadataField(type.getAddressField("_klasses"), 0); 49 hasClassMirrorHolderField = new CIntField(type.getCIntegerField("_has_class_mirror_holder"), 0); 50 dictionaryField = type.getAddressField("_dictionary"); 51 } 52 53 private static long classLoaderFieldOffset; 54 private static AddressField nextField; 55 private static MetadataField klassesField; 56 private static CIntField hasClassMirrorHolderField; 57 private static AddressField dictionaryField; 58 59 public ClassLoaderData(Address addr) { 60 super(addr); 61 } 62 63 public Dictionary dictionary() { 64 Address tmp = dictionaryField.getValue(); 65 return (Dictionary) VMObjectFactory.newObject(Dictionary.class, tmp); 66 } 67 68 public static ClassLoaderData instantiateWrapperFor(Address addr) { 69 if (addr == null) { 70 return null; 71 } 72 return new ClassLoaderData(addr); 73 } 74 75 public Oop getClassLoader() { 76 Address addr = getAddress().addOffsetTo(classLoaderFieldOffset); 77 VMOopHandle vmOopHandle = VMObjectFactory.newObject(VMOopHandle.class, addr); 78 return vmOopHandle.resolve(); 79 } 80 81 public boolean gethasClassMirrorHolder() { 82 return hasClassMirrorHolderField.getValue(this) != 0; 83 } 84 85 public ClassLoaderData next() { 86 return instantiateWrapperFor(nextField.getValue(getAddress())); 87 } 88 89 public Klass getKlasses() { return (Klass)klassesField.getValue(this); } 90 91 /** Lookup an already loaded class. If not found null is returned. */ 92 public Klass find(String className) { 93 for (Klass l = getKlasses(); l != null; l = l.getNextLinkKlass()) { 94 if (l.getName().equals(className)) { 95 return l; 96 } 97 } 98 return null; 99 } 100 101 /** Iterate over all klasses - including object, primitive 102 array klasses */ 103 public void classesDo(ClassLoaderDataGraph.ClassVisitor v) { 104 for (Klass l = getKlasses(); l != null; l = l.getNextLinkKlass()) { 105 v.visit(l); 106 } 107 } 108 109 /** Iterate over all klasses in the dictionary, including initiating loader. */ 110 public void allEntriesDo(ClassLoaderDataGraph.ClassAndLoaderVisitor v) { 111 for (Klass l = getKlasses(); l != null; l = l.getNextLinkKlass()) { 112 dictionary().allEntriesDo(v, getClassLoader()); 113 } 114 } 115 }