1 /*
2 * Copyright (c) 2011, 2015, 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 * @requires (os.simpleArch == "x64" | os.simpleArch == "sparcv9" | os.simpleArch == "aarch64")
27 * @library ../../../../../
28 * @modules jdk.vm.ci/jdk.vm.ci.meta
29 * jdk.vm.ci/jdk.vm.ci.runtime
30 * java.base/jdk.internal.misc
31 * @build jdk.vm.ci.runtime.test.RedefineClassTest
32 * @run junit/othervm -XX:+UnlockExperimentalVMOptions -XX:+EnableJVMCI jdk.vm.ci.runtime.test.RedefineClassTest
33 */
34
35 package jdk.vm.ci.runtime.test;
36
37 import static org.junit.Assume.assumeTrue;
38
39 import java.io.FileOutputStream;
40 import java.io.IOException;
41 import java.io.InputStream;
42 import java.lang.instrument.ClassFileTransformer;
43 import java.lang.instrument.IllegalClassFormatException;
44 import java.lang.instrument.Instrumentation;
45 import java.lang.management.ManagementFactory;
46 import java.lang.reflect.Method;
47 import java.nio.file.Files;
48 import java.nio.file.Path;
49 import java.security.ProtectionDomain;
50 import java.util.Arrays;
51 import java.util.jar.Attributes;
52 import java.util.jar.JarEntry;
53 import java.util.jar.JarOutputStream;
54 import java.util.jar.Manifest;
55
56 import javax.tools.ToolProvider;
57
58 import jdk.vm.ci.meta.ResolvedJavaMethod;
59
60 import org.junit.Assert;
61 import org.junit.Test;
62
63 /**
64 * Tests that {@link ResolvedJavaMethod}s are safe in the context of class redefinition being used
65 * to redefine the method to which they refer.
66 */
67 public class RedefineClassTest extends TypeUniverse {
68
69 static class Foo {
70 public static Object getName() {
71 return "foo";
72 }
73 }
74
75 @Test
76 public void test() throws Throwable {
77
78 Method fooMethod = Foo.class.getDeclaredMethod("getName");
79
80 ResolvedJavaMethod foo1 = metaAccess.lookupJavaMethod(fooMethod);
81 ResolvedJavaMethod foo2 = metaAccess.lookupJavaMethod(fooMethod);
82
83 String foo1Code = Arrays.toString(foo1.getCode());
84 String foo2Code = Arrays.toString(foo2.getCode());
85
86 Assert.assertEquals("foo", Foo.getName());
87
88 redefineFoo();
89 System.gc();
90
91 // Make sure the transformation happened
92 Assert.assertEquals("bar", Foo.getName());
93
94 Assert.assertEquals(foo1Code, Arrays.toString(foo1.getCode()));
95 Assert.assertEquals(foo2Code, Arrays.toString(foo1.getCode()));
96 }
97
98 /**
99 * Adds the class file bytes for a given class to a JAR stream.
100 */
101 static void add(JarOutputStream jar, Class<?> c) throws IOException {
102 String name = c.getName();
103 String classAsPath = name.replace('.', '/') + ".class";
104 jar.putNextEntry(new JarEntry(classAsPath));
105
106 InputStream stream = c.getClassLoader().getResourceAsStream(classAsPath);
107
108 int nRead;
109 byte[] buf = new byte[1024];
110 while ((nRead = stream.read(buf, 0, buf.length)) != -1) {
111 jar.write(buf, 0, nRead);
112 }
113
114 jar.closeEntry();
115 }
116
117 protected void redefineFoo() throws Exception {
118 Manifest manifest = new Manifest();
119 manifest.getMainAttributes().put(Attributes.Name.MANIFEST_VERSION, "1.0");
120 Attributes mainAttrs = manifest.getMainAttributes();
121 mainAttrs.putValue("Agent-Class", FooAgent.class.getName());
122 mainAttrs.putValue("Can-Redefine-Classes", "true");
123 mainAttrs.putValue("Can-Retransform-Classes", "true");
124
125 Path jar = Files.createTempFile("myagent", ".jar");
126 try {
127 JarOutputStream jarStream = new JarOutputStream(new FileOutputStream(jar.toFile()), manifest);
128 add(jarStream, FooAgent.class);
129 add(jarStream, FooTransformer.class);
130 jarStream.close();
131
132 loadAgent(jar);
133 } finally {
134 Files.deleteIfExists(jar);
135 }
136 }
137
138 public static void loadAgent(Path agent) throws Exception {
139 String vmName = ManagementFactory.getRuntimeMXBean().getName();
140 int p = vmName.indexOf('@');
141 assumeTrue(p != -1);
142 String pid = vmName.substring(0, p);
143 ClassLoader cl = ToolProvider.getSystemToolClassLoader();
144 Class<?> c = Class.forName("com.sun.tools.attach.VirtualMachine", true, cl);
145 Method attach = c.getDeclaredMethod("attach", String.class);
146 Method loadAgent = c.getDeclaredMethod("loadAgent", String.class, String.class);
147 Method detach = c.getDeclaredMethod("detach");
148 Object vm = attach.invoke(null, pid);
149 loadAgent.invoke(vm, agent.toString(), "");
150 detach.invoke(vm);
151 }
152
153 public static class FooAgent {
154
155 public static void agentmain(@SuppressWarnings("unused") String args, Instrumentation inst) throws Exception {
156 if (inst.isRedefineClassesSupported() && inst.isRetransformClassesSupported()) {
157 inst.addTransformer(new FooTransformer(), true);
158 Class<?>[] allClasses = inst.getAllLoadedClasses();
159 for (int i = 0; i < allClasses.length; i++) {
160 Class<?> c = allClasses[i];
161 if (c == Foo.class) {
162 inst.retransformClasses(new Class<?>[]{c});
163 }
164 }
165 }
166 }
167 }
168
169 /**
170 * This transformer replaces the first instance of the constant "foo" in the class file for
171 * {@link Foo} with "bar".
172 */
173 static class FooTransformer implements ClassFileTransformer {
174
175 @Override
176 public byte[] transform(ClassLoader cl, String className, Class<?> classBeingRedefined, ProtectionDomain protectionDomain, byte[] classfileBuffer) throws IllegalClassFormatException {
177 if (Foo.class.equals(classBeingRedefined)) {
178 String cf = new String(classfileBuffer);
179 int i = cf.indexOf("foo");
180 Assert.assertTrue("cannot find \"foo\" constant in " + Foo.class.getSimpleName() + "'s class file", i > 0);
181 classfileBuffer[i] = 'b';
182 classfileBuffer[i + 1] = 'a';
183 classfileBuffer[i + 2] = 'r';
184 }
185 return classfileBuffer;
186 }
187 }
188 }