1 /*
2 * Copyright (c) 2018, 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. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package jdk.jfr.api.metadata.eventtype;
27
28 import java.io.ByteArrayOutputStream;
29 import java.io.IOException;
30 import java.io.InputStream;
31 import java.nio.file.Files;
32 import java.nio.file.Path;
33
34 import jdk.jfr.Event;
35 import jdk.jfr.EventType;
36 import jdk.jfr.FlightRecorder;
37 import jdk.jfr.Recording;
38 import jdk.jfr.consumer.RecordingFile;
39 import jdk.jfr.internal.JVM;
40
41 /*
42 * @test
43 * @key jfr
44 * @summary Test that verifies event metadata is removed when an event class is unloaded.
45 *
46 * @library /test/lib
47 * @modules jdk.jfr/jdk.jfr.internal
48 * java.base/jdk.internal.misc
49 *
50 * @run main/othervm -Xlog:class+unload -Xlog:gc jdk.jfr.api.metadata.eventtype.TestUnloadingEventClass
51 */
52 public class TestUnloadingEventClass {
53
54 private static final String EVENT_NAME = "jdk.jfr.api.metadata.eventtype.TestUnloadingEventClass$ToBeUnloaded";
55
56 public static class ToBeUnloaded extends Event {
57 }
58
59 static public class MyClassLoader extends ClassLoader {
60 public MyClassLoader() {
61 super("MyClassLoader", null);
62 }
63
64 public final Class<?> defineClass(String name, byte[] b) {
65 return super.defineClass(name, b, 0, b.length);
66 }
67 }
68
69 private static final JVM jvm = JVM.getJVM();
70 public static ClassLoader myClassLoader;
71
72 public static void main(String[] args) throws Throwable {
73 assertEventTypeNotAvailable();
74 myClassLoader = createClassLoaderWithEventClass();
75
76 try (Recording r0 = new Recording()) {
77 r0.start();
78 r0.stop();
79 if (getEventType(r0, 0, EVENT_NAME) == null) {
80 throw new Exception("Expected event class to have corresponding event type");
81 }
82 }
83
84 try (Recording r1 = new Recording(); Recording r2 = new Recording(); Recording r3 = new Recording()) {
85 r1.start();
86 r2.start();
87 System.out.println("Class loader with name " + myClassLoader.getName() + " is on the heap");
88 unLoadEventClass();
89 r3.start();
90
91 assertEventTypeNotAvailable();
92 r3.stop();
93 r2.stop();
94 r1.stop();
95
96 if (getEventType(r1, 1, EVENT_NAME) == null) {
97 throw new Exception("Expected event class to have corresponding event type in recording with all chunks");
98 }
99 if (getEventType(r2, 2, EVENT_NAME) == null) {
100 throw new Exception("Expected event class to have corresponding event type in recording where event class was unloaded");
101 }
102 if (getEventType(r3, 3, EVENT_NAME) != null) {
103 throw new Exception("Unexpected metadata found for event class tha has been unloaded.");
104 }
105 }
106 }
107
108 private static MyClassLoader createClassLoaderWithEventClass() throws Exception {
109 String resourceName = EVENT_NAME.replace('.', '/') + ".class";
110 try (InputStream is = TestUnloadingEventClass.class.getClassLoader().getResourceAsStream(resourceName)) {
111 ByteArrayOutputStream baos = new ByteArrayOutputStream();
112 byte[] buffer = new byte[4096];
113 int byteValue = 0;
114 while ((byteValue = is.read(buffer, 0, buffer.length)) != -1) {
115 baos.write(buffer, 0, byteValue);
116 }
117 baos.flush();
118 MyClassLoader myClassLoader = new MyClassLoader();
119 Class<?> eventClass = myClassLoader.defineClass(EVENT_NAME, baos.toByteArray());
120 if (eventClass == null) {
121 throw new Exception("Could not define test class");
122 }
123 if (eventClass.getSuperclass() != Event.class) {
124 throw new Exception("Superclass should be jdk.jfr.Event");
125 }
126 if (eventClass.getSuperclass().getClassLoader() != null) {
127 throw new Exception("Class loader of jdk.jfr.Event should be null");
128 }
129 if (eventClass.getClassLoader() != myClassLoader) {
130 throw new Exception("Incorrect class loader for event class");
131 }
132 eventClass.newInstance(); // force <clinit>
133 return myClassLoader;
134 }
135 }
136
137 private static void unLoadEventClass() throws Exception {
138 long firstCount = jvm.getUnloadedEventClassCount();
139 System.out.println("Initial unloaded count: " + firstCount);
140 myClassLoader = null;
141 System.out.println("Cleared reference to MyClassLoader");
142 long newCount = 0;
143 do {
144 System.out.println("GC triggered");
145 System.gc();
146 Thread.sleep(1000);
147 newCount = jvm.getUnloadedEventClassCount();
148 System.out.println("Unloaded count: " + newCount);
149 } while (firstCount + 1 != newCount);
150 System.out.println("Event class unloaded!");
151 System.out.println("Event classes currently on the heap:");
152 for (Class<?> eventClass : JVM.getJVM().getAllEventClasses()) {
153 System.out.println(eventClass + " " + (eventClass.getClassLoader() != null ? eventClass.getClassLoader().getName() : null));
154 }
155
156 }
157
158 private static void assertEventTypeNotAvailable() throws Exception {
159 for (EventType type : FlightRecorder.getFlightRecorder().getEventTypes()) {
160 if (type.getName().equals(EVENT_NAME)) {
161 throw new Exception("Event type should not be available");
162 }
163 }
164 }
165
166 private static Object getEventType(Recording r, long id, String eventName) throws IOException {
167 Path p = Files.createTempFile("recording-" + id + "_", ".jfr");
168 r.dump(p);
169 try (RecordingFile rf = new RecordingFile(p)) {
170 for (EventType et : rf.readEventTypes()) {
171 if (et.getName().equals(eventName)) {
172 return et;
173 }
174 }
175
176 }
177 return null;
178 }
179 }
180