1 /* 2 * Copyright (c) 2016, 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 import java.lang.instrument.*; 24 25 public class GetObjectSizeClassAgent { 26 27 static Instrumentation instrumentation; 28 premain(String agentArgs, Instrumentation instrumentation)29 public static void premain(String agentArgs, Instrumentation instrumentation) { 30 GetObjectSizeClassAgent.instrumentation = instrumentation; 31 } 32 main(String[] args)33 public static void main(String[] args) throws Exception { 34 long sizeA = instrumentation.getObjectSize(A.class); 35 long sizeB = instrumentation.getObjectSize(B.class); 36 37 if (sizeA != sizeB) { 38 throw new RuntimeException("java.lang.Class sizes disagree: " + sizeA + " vs. " + sizeB); 39 } 40 41 System.out.println("GetObjectSizeClass passed"); 42 } 43 44 static class A { 45 } 46 47 static class B { m()48 void m() {} 49 } 50 51 } 52