1 /*
2 * Copyright (c) 2024, 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 * @test
26 * @summary Test for value class retransformation
27 *
28 * @library /test/lib
29 * @modules java.instrument
30 * @enablePreview
31 *
32 * @run main RetransformValueClass buildAgent
33 *
34 * @run main/othervm -javaagent:testAgent.jar RetransformValueClass
35 */
36
37 import java.lang.instrument.Instrumentation;
38 import java.lang.instrument.ClassFileTransformer;
39 import java.security.ProtectionDomain;
40
41 import jdk.test.lib.helpers.ClassFileInstaller;
42
43 /*
44 * The test verifies Instrumentation.retransformClasses() (and JVMTI function RetransformClasses)
45 * works with value classes (i.e. JVMTI JvmtiClassFileReconstituter correctly restores class bytes).
46 */
47
48 value class ValueClass {
49 public int f1;
50 public String f2;
51
52 public ValueClass(int v1, String v2) {
53 f1 = v1;
54 f2 = v2;
55 }
56 }
57
58 public class RetransformValueClass {
59
60 public static void main (String[] args) throws Exception {
61 if (args.length == 1 && "buildAgent".equals(args[0])) {
62 buildAgent();
63 } else {
64 runTest();
65 }
66 }
67
68 static void buildAgent() throws Exception {
69 String manifest = "Premain-Class: RetransformValueClass\nCan-Redefine-Classes: true\nCan-Retransform-Classes: true\n";
70 ClassFileInstaller.writeJar("testAgent.jar", ClassFileInstaller.Manifest.fromString(manifest), "RetransformValueClass");
71 }
72
73 // agent implementation
74 static Instrumentation instrumentation;
75 public static void premain(String agentArgs, Instrumentation inst) {
76 instrumentation = inst;
77 }
78
79 // test implementation
80 static final Class targetClass = ValueClass.class;
81 static final String targetClassName = targetClass.getName();
82 static boolean transformToOriginalClassbytes = false;
83
84 static void runTest() throws Exception {
85 instrumentation.addTransformer(new Transformer(), true);
86
87 instrumentation.retransformClasses(targetClass);
88
89 transformToOriginalClassbytes = true;
90 instrumentation.retransformClasses(targetClass);
91 }
92
93
94 static class Transformer implements ClassFileTransformer {
95 public Transformer() {
96 }
97
98 public byte[] transform(ClassLoader loader, String className,
99 Class<?> classBeingRedefined, ProtectionDomain protectionDomain, byte[] classfileBuffer) {
100
101 if (className.equals(targetClassName)) {
102 log("Transformer sees '" + className + "' of " + classfileBuffer.length + " bytes.");
103 if (transformToOriginalClassbytes) {
104 return classfileBuffer;
105 } else {
106 return null;
107 }
108 }
109 return null;
110 }
111 }
112
113 static void log(Object o) {
114 System.out.println(String.valueOf(o));
115 }
116 }