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comparison jvmci/jdk.vm.ci.runtime.test/src/jdk/vm/ci/runtime/test/RedefineClassTest.java @ 22672:1bbd4a7c274b

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Rename jdk.internal.jvmci to jdk.vm.ci
author Tom Rodriguez <tom.rodriguez@oracle.com>
date Thu, 08 Oct 2015 17:28:41 -0700
parents jvmci/jdk.internal.jvmci.runtime.test/src/jdk/internal/jvmci/runtime/test/RedefineClassTest.java@ec96f33a101d
children
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22671:97f30e4d0e95 22672:1bbd4a7c274b
1 /*
2 * Copyright (c) 2011, 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 package jdk.vm.ci.runtime.test;
24
25 import static org.junit.Assume.assumeTrue;
26
27 import java.io.FileOutputStream;
28 import java.io.IOException;
29 import java.io.InputStream;
30 import java.lang.instrument.ClassFileTransformer;
31 import java.lang.instrument.IllegalClassFormatException;
32 import java.lang.instrument.Instrumentation;
33 import java.lang.management.ManagementFactory;
34 import java.lang.reflect.Method;
35 import java.nio.file.Files;
36 import java.nio.file.Path;
37 import java.security.ProtectionDomain;
38 import java.util.Arrays;
39 import java.util.jar.Attributes;
40 import java.util.jar.JarEntry;
41 import java.util.jar.JarOutputStream;
42 import java.util.jar.Manifest;
43
44 import javax.tools.ToolProvider;
45
46 import jdk.vm.ci.meta.ResolvedJavaMethod;
47
48 import org.junit.Assert;
49 import org.junit.Test;
50
51 /**
52 * Tests that {@link ResolvedJavaMethod}s are safe in the context of class redefinition being used
53 * to redefine the method to which they refer.
54 */
55 public class RedefineClassTest extends TypeUniverse {
56
57 static class Foo {
58 public static Object getName() {
59 return "foo";
60 }
61 }
62
63 @Test
64 public void test() throws Throwable {
65
66 Method fooMethod = Foo.class.getDeclaredMethod("getName");
67
68 ResolvedJavaMethod foo1 = metaAccess.lookupJavaMethod(fooMethod);
69 ResolvedJavaMethod foo2 = metaAccess.lookupJavaMethod(fooMethod);
70
71 String foo1Code = Arrays.toString(foo1.getCode());
72 String foo2Code = Arrays.toString(foo2.getCode());
73
74 Assert.assertEquals("foo", Foo.getName());
75
76 redefineFoo();
77 System.gc();
78
79 // Make sure the transformation happened
80 Assert.assertEquals("bar", Foo.getName());
81
82 Assert.assertEquals(foo1Code, Arrays.toString(foo1.getCode()));
83 Assert.assertEquals(foo2Code, Arrays.toString(foo1.getCode()));
84 }
85
86 /**
87 * Adds the class file bytes for a given class to a JAR stream.
88 */
89 static void add(JarOutputStream jar, Class<?> c) throws IOException {
90 String name = c.getName();
91 String classAsPath = name.replace('.', '/') + ".class";
92 jar.putNextEntry(new JarEntry(classAsPath));
93
94 InputStream stream = c.getClassLoader().getResourceAsStream(classAsPath);
95
96 int nRead;
97 byte[] buf = new byte[1024];
98 while ((nRead = stream.read(buf, 0, buf.length)) != -1) {
99 jar.write(buf, 0, nRead);
100 }
101
102 jar.closeEntry();
103 }
104
105 protected void redefineFoo() throws Exception {
106 Manifest manifest = new Manifest();
107 manifest.getMainAttributes().put(Attributes.Name.MANIFEST_VERSION, "1.0");
108 Attributes mainAttrs = manifest.getMainAttributes();
109 mainAttrs.putValue("Agent-Class", FooAgent.class.getName());
110 mainAttrs.putValue("Can-Redefine-Classes", "true");
111 mainAttrs.putValue("Can-Retransform-Classes", "true");
112
113 Path jar = Files.createTempFile("myagent", ".jar");
114 try {
115 JarOutputStream jarStream = new JarOutputStream(new FileOutputStream(jar.toFile()), manifest);
116 add(jarStream, FooAgent.class);
117 add(jarStream, FooTransformer.class);
118 jarStream.close();
119
120 loadAgent(jar);
121 } finally {
122 Files.deleteIfExists(jar);
123 }
124 }
125
126 public static void loadAgent(Path agent) throws Exception {
127 String vmName = ManagementFactory.getRuntimeMXBean().getName();
128 int p = vmName.indexOf('@');
129 assumeTrue("VM name not in <pid>@<host> format: " + vmName, p != -1);
130 String pid = vmName.substring(0, p);
131 ClassLoader cl = ToolProvider.getSystemToolClassLoader();
132 Class<?> c = Class.forName("com.sun.tools.attach.VirtualMachine", true, cl);
133 Method attach = c.getDeclaredMethod("attach", String.class);
134 Method loadAgent = c.getDeclaredMethod("loadAgent", String.class, String.class);
135 Method detach = c.getDeclaredMethod("detach");
136 Object vm = attach.invoke(null, pid);
137 loadAgent.invoke(vm, agent.toString(), "");
138 detach.invoke(vm);
139 }
140
141 public static class FooAgent {
142
143 public static void agentmain(@SuppressWarnings("unused") String args, Instrumentation inst) throws Exception {
144 if (inst.isRedefineClassesSupported() && inst.isRetransformClassesSupported()) {
145 inst.addTransformer(new FooTransformer(), true);
146 Class<?>[] allClasses = inst.getAllLoadedClasses();
147 for (int i = 0; i < allClasses.length; i++) {
148 Class<?> c = allClasses[i];
149 if (c == Foo.class) {
150 inst.retransformClasses(new Class<?>[]{c});
151 }
152 }
153 }
154 }
155 }
156
157 /**
158 * This transformer replaces the first instance of the constant "foo" in the class file for
159 * {@link Foo} with "bar".
160 */
161 static class FooTransformer implements ClassFileTransformer {
162
163 @Override
164 public byte[] transform(ClassLoader cl, String className, Class<?> classBeingRedefined, ProtectionDomain protectionDomain, byte[] classfileBuffer) throws IllegalClassFormatException {
165 if (Foo.class.equals(classBeingRedefined)) {
166 String cf = new String(classfileBuffer);
167 int i = cf.indexOf("foo");
168 Assert.assertTrue("cannot find \"foo\" constant in " + Foo.class.getSimpleName() + "'s class file", i > 0);
169 classfileBuffer[i] = 'b';
170 classfileBuffer[i + 1] = 'a';
171 classfileBuffer[i + 2] = 'r';
172 }
173 return classfileBuffer;
174 }
175 }
176 }