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