1 /*
 2  * Copyright (c) 2023, 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 import java.lang.instrument.ClassFileTransformer;
25 import java.lang.instrument.Instrumentation;
26 import java.util.Map;
27 import java.util.Set;
28 
29 /**
30  * Agent used by TraceUsageTest. The premain and agentmain methods invoke Instrumentation
31  * methods so the usages can be traced by the test.
32  */
33 public class TraceUsageAgent {
34     public static void premain(String methodNames, Instrumentation inst) throws Exception {
35         test(methodNames, inst);
36     }
37 
38     public static void agentmain(String methodNames, Instrumentation inst) throws Exception {
39         test(methodNames, inst);
40     }
41 
42     private static void test(String methodNames, Instrumentation inst) throws Exception {
43         for (String methodName : methodNames.split(",")) {
44             switch (methodName) {
45                 case "addTransformer" -> {
46                     var transformer = new ClassFileTransformer() { };
47                     inst.addTransformer(transformer);
48                 }
49                 case "retransformClasses" -> {
50                     inst.retransformClasses(Integer.class);
51                 }
52                 case "redefineModule" -> {
53                     Module base = Object.class.getModule();
54                     inst.redefineModule(base, Set.of(), Map.of(), Map.of(), Set.of(), Map.of());
55                 }
56                 default -> {
57                     throw new RuntimeException("Unknown method name: " + methodName);
58                 }
59             }
60         }
61     }
62 }