1 /*
2 * Copyright (c) 2014, 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 MethodUnloadingTest
26 * @bug 8029443
27 * @summary Tests the unloading of methods to to class unloading
28 * @modules java.base/jdk.internal.misc
29 * @library /testlibrary /test/lib /
30 *
31 * @build compiler.classUnloading.methodUnloading.TestMethodUnloading
32 * compiler.classUnloading.methodUnloading.WorkerClass
33 * @run driver ClassFileInstaller sun.hotspot.WhiteBox
34 * sun.hotspot.WhiteBox$WhiteBoxPermission
35 * @run main/othervm -Xbootclasspath/a:. -XX:+IgnoreUnrecognizedVMOptions
36 * -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI
37 * -XX:-BackgroundCompilation -XX:-UseCompressedOops
38 * -XX:CompileCommand=compileonly,compiler.classUnloading.methodUnloading.TestMethodUnloading::doWork
39 * compiler.classUnloading.methodUnloading.TestMethodUnloading
40 */
41
42 package compiler.classUnloading.methodUnloading;
43
44 import sun.hotspot.WhiteBox;
45
46 import java.lang.reflect.Method;
47 import java.net.URL;
48 import java.net.URLClassLoader;
49
50 public class TestMethodUnloading {
51 private static final String workerClassName = "compiler.classUnloading.methodUnloading.WorkerClass";
52 private static int work = -1;
53
54 private static final WhiteBox WHITE_BOX = WhiteBox.getWhiteBox();
55 private static int COMP_LEVEL_SIMPLE = 1;
56 private static int COMP_LEVEL_FULL_OPTIMIZATION = 4;
57
58 /**
59 * Does some work by either using the workerClass or locally producing values.
60 * @param workerClass Class performing some work (will be unloaded)
61 * @param useWorker If true the workerClass is used
62 */
63 static private void doWork(Class<?> workerClass, boolean useWorker) throws InstantiationException, IllegalAccessException {
64 if (useWorker) {
65 // Create a new instance
66 Object worker = workerClass.newInstance();
67 // We would like to call a method of WorkerClass here but we cannot cast to WorkerClass
68 // because the class was loaded by a different class loader. One solution would be to use
69 // reflection but since we want C2 to implement the call as an optimized IC we call
70 // Object::hashCode() here which actually calls WorkerClass::hashCode().
71 // C2 will then implement this call as an optimized IC that points to a to-interpreter stub
72 // referencing the Method* for WorkerClass::hashCode().
73 work = worker.hashCode();
74 if (work != 42) {
75 new RuntimeException("Work not done");
76 }
77 } else {
78 // Do some important work here
79 work = 1;
80 }
81 }
82
83 /**
84 * Makes sure that method is compiled by forcing compilation if not yet compiled.
85 * @param m Method to be checked
86 */
87 static private void makeSureIsCompiled(Method m) {
88 // Make sure background compilation is disabled
89 if (WHITE_BOX.getBooleanVMFlag("BackgroundCompilation")) {
90 throw new RuntimeException("Background compilation enabled");
91 }
92
93 // Check if already compiled
94 if (!WHITE_BOX.isMethodCompiled(m)) {
95 // If not, try to compile it with C2
96 if(!WHITE_BOX.enqueueMethodForCompilation(m, COMP_LEVEL_FULL_OPTIMIZATION)) {
97 // C2 compiler not available, try to compile with C1
98 WHITE_BOX.enqueueMethodForCompilation(m, COMP_LEVEL_SIMPLE);
99 }
100 // Because background compilation is disabled, method should now be compiled
101 if(!WHITE_BOX.isMethodCompiled(m)) {
102 throw new RuntimeException(m + " not compiled");
103 }
104 }
105 }
106
107 /**
108 * This test creates stale Method* metadata in a to-interpreter stub of an optimized IC.
109 *
110 * The following steps are performed:
111 * (1) A workerClass is loaded by a custom class loader
112 * (2) The method doWork that calls a method of the workerClass is compiled. The call
113 * is implemented as an optimized IC calling a to-interpreted stub. The to-interpreter
114 * stub contains a Method* to a workerClass method.
115 * (3) Unloading of the workerClass is enforced. The to-interpreter stub now contains a dead Method*.
116 * (4) Depending on the implementation of the IC, the compiled version of doWork should still be
117 * valid. We call it again without using the workerClass.
118 */
119 static public void main(String[] args) throws Exception {
120 // (1) Create a custom class loader with no parent class loader
121 URL url = TestMethodUnloading.class.getProtectionDomain().getCodeSource().getLocation();
122 URLClassLoader loader = new URLClassLoader(new URL[] {url}, null);
123
124 // Load worker class with custom class loader
125 Class<?> workerClass = Class.forName(workerClassName, true, loader);
126
127 // (2) Make sure all paths of doWork are profiled and compiled
128 for (int i = 0; i < 100000; ++i) {
129 doWork(workerClass, true);
130 doWork(workerClass, false);
131 }
132
133 // Make sure doWork is compiled now
134 Method doWork = TestMethodUnloading.class.getDeclaredMethod("doWork", Class.class, boolean.class);
135 makeSureIsCompiled(doWork);
136
137 // (3) Throw away class loader and reference to workerClass to allow unloading
138 loader.close();
139 loader = null;
140 workerClass = null;
141
142 // Force garbage collection to trigger unloading of workerClass
143 // Dead reference to WorkerClass::hashCode triggers JDK-8029443
144 WHITE_BOX.fullGC();
145
146 // (4) Depending on the implementation of the IC, the compiled version of doWork
147 // may still be valid here. Execute it without a workerClass.
148 doWork(null, false);
149 if (work != 1) {
150 throw new RuntimeException("Work not done");
151 }
152
153 doWork(Object.class, false);
154 }
155 }