--- /dev/null Tue Mar 29 13:56:37 2011 +++ new/agent/src/share/classes/sun/jvm/hotspot/oops/java_lang_Class.java Tue Mar 29 13:56:37 2011 @@ -0,0 +1,77 @@ +/* + * Copyright (c) 2011, Oracle and/or its affiliates. All rights reserved. + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. + * + * This code is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 only, as + * published by the Free Software Foundation. + * + * This code is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * version 2 for more details (a copy is included in the LICENSE file that + * accompanied this code). + * + * You should have received a copy of the GNU General Public License version + * 2 along with this work; if not, write to the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. + * + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA + * or visit www.oracle.com if you need additional information or have any + * questions. + * + */ + +package sun.jvm.hotspot.oops; + +import java.util.*; + +import sun.jvm.hotspot.debugger.*; +import sun.jvm.hotspot.memory.*; +import sun.jvm.hotspot.runtime.*; +import sun.jvm.hotspot.types.Type; +import sun.jvm.hotspot.types.TypeDataBase; +import sun.jvm.hotspot.utilities.*; +import sun.jvm.hotspot.jdi.JVMTIThreadState; + +/** A utility class encapsulating useful oop operations */ + +// initialize fields for java.lang.Class +public class java_lang_Class { + + // java.lang.Class fields + static OopField klassField; + static IntField oopSizeField; + + static { + VM.registerVMInitializedObserver(new Observer() { + public void update(Observable o, Object data) { + initialize(VM.getVM().getTypeDataBase()); + } + }); + } + + private static synchronized void initialize(TypeDataBase db) { + // klass and oop_size are HotSpot magic fields and hence we can't + // find them from InstanceKlass for java.lang.Class. + Type jlc = db.lookupType("java_lang_Class"); + int klassOffset = (int) jlc.getCIntegerField("klass_offset").getValue(); + if (VM.getVM().isCompressedOopsEnabled()) { + klassField = new NarrowOopField(new NamedFieldIdentifier("klass"), klassOffset, true); + } else { + klassField = new OopField(new NamedFieldIdentifier("klass"), klassOffset, true); + } + int oopSizeOffset = (int) jlc.getCIntegerField("oop_size_offset").getValue(); + oopSizeField = new IntField(new NamedFieldIdentifier("oop_size"), oopSizeOffset, true); + } + + /** get klassOop field at offset hc_klass_offset from a java.lang.Class object */ + public static Klass asKlass(Oop aClass) { + return (Klass) java_lang_Class.klassField.getValue(aClass); + } + + /** get oop_size field at offset oop_size_offset from a java.lang.Class object */ + public static long getOopSize(Oop aClass) { + return java_lang_Class.oopSizeField.getValue(aClass); + } +}