1 /*
2 * Copyright (c) 2014, 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 import sun.hotspot.WhiteBox;
25 import jdk.internal.misc.Unsafe;
26
27 import java.io.IOException;
28 import java.lang.reflect.Method;
29 import java.net.URL;
30 import java.net.URLConnection;
31
32 /*
33 * @test TestAnonymousClassUnloading
34 * @bug 8054402
35 * @summary "Tests unloading of anonymous classes."
36 * @library /testlibrary /test/lib
37 * @modules java.base/jdk.internal.misc
38 * @compile TestAnonymousClassUnloading.java
39 * @run main ClassFileInstaller TestAnonymousClassUnloading
40 * sun.hotspot.WhiteBox
41 * sun.hotspot.WhiteBox$WhiteBoxPermission
42 * @run main/othervm -Xbootclasspath/a:. -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI -XX:-BackgroundCompilation TestAnonymousClassUnloading
43 */
44 public class TestAnonymousClassUnloading {
45 private static final WhiteBox WHITE_BOX = WhiteBox.getWhiteBox();
46 private static final Unsafe UNSAFE = Unsafe.getUnsafe();
47 private static int COMP_LEVEL_SIMPLE = 1;
48 private static int COMP_LEVEL_FULL_OPTIMIZATION = 4;
49
50 /**
51 * We override hashCode here to be able to access this implementation
52 * via an Object reference (we cannot cast to TestAnonymousClassUnloading).
53 */
54 @Override
55 public int hashCode() {
56 return 42;
57 }
58
59 /**
60 * Does some work by using the anonymousClass.
61 * @param anonymousClass Class performing some work (will be unloaded)
62 */
63 static private void doWork(Class<?> anonymousClass) throws InstantiationException, IllegalAccessException {
64 // Create a new instance
65 Object anon = anonymousClass.newInstance();
66 // We would like to call a method of anonymousClass here but we cannot cast because the class
67 // was loaded by a different class loader. One solution would be to use reflection but since
68 // we want C2 to implement the call as an IC we call Object::hashCode() here which actually
69 // calls anonymousClass::hashCode(). C2 will then implement this call as an IC.
70 if (anon.hashCode() != 42) {
71 new RuntimeException("Work not done");
72 }
73 }
74
75 /**
76 * Makes sure that method is compiled by forcing compilation if not yet compiled.
77 * @param m Method to be checked
78 */
79 static private void makeSureIsCompiled(Method m) {
80 // Make sure background compilation is disabled
81 if (WHITE_BOX.getBooleanVMFlag("BackgroundCompilation")) {
82 throw new RuntimeException("Background compilation enabled");
83 }
84
85 // Check if already compiled
86 if (!WHITE_BOX.isMethodCompiled(m)) {
87 // If not, try to compile it with C2
88 if(!WHITE_BOX.enqueueMethodForCompilation(m, COMP_LEVEL_FULL_OPTIMIZATION)) {
89 // C2 compiler not available, try to compile with C1
90 WHITE_BOX.enqueueMethodForCompilation(m, COMP_LEVEL_SIMPLE);
91 }
92 // Because background compilation is disabled, method should now be compiled
93 if(!WHITE_BOX.isMethodCompiled(m)) {
94 throw new RuntimeException(m + " not compiled");
95 }
96 }
97 }
98
99 /**
100 * This test creates stale Klass* metadata referenced by a compiled IC.
101 *
102 * The following steps are performed:
103 * (1) An anonymous version of TestAnonymousClassUnloading is loaded by a custom class loader
104 * (2) The method doWork that calls a method of the anonymous class is compiled. The call
105 * is implemented as an IC referencing Klass* metadata of the anonymous class.
106 * (3) Unloading of the anonymous class is enforced. The IC now references dead metadata.
107 */
108 static public void main(String[] args) throws Exception {
109 // (1) Load an anonymous version of this class using the corresponding Unsafe method
110 URL classUrl = TestAnonymousClassUnloading.class.getResource("TestAnonymousClassUnloading.class");
111 URLConnection connection = classUrl.openConnection();
112
113 int length = connection.getContentLength();
114 byte[] classBytes = connection.getInputStream().readAllBytes();
115 if (length != -1 && classBytes.length != length) {
116 throw new IOException("Expected:" + length + ", actual: " + classBytes.length);
117 }
118
119 Class<?> anonymousClass = UNSAFE.defineAnonymousClass(TestAnonymousClassUnloading.class, classBytes, null);
120
121 // (2) Make sure all paths of doWork are profiled and compiled
122 for (int i = 0; i < 100000; ++i) {
123 doWork(anonymousClass);
124 }
125
126 // Make sure doWork is compiled now
127 Method doWork = TestAnonymousClassUnloading.class.getDeclaredMethod("doWork", Class.class);
128 makeSureIsCompiled(doWork);
129
130 // (3) Throw away reference to anonymousClass to allow unloading
131 anonymousClass = null;
132
133 // Force garbage collection to trigger unloading of anonymousClass
134 // Dead metadata reference to anonymousClass triggers JDK-8054402
135 WHITE_BOX.fullGC();
136 }
137 }