TestMethodUnloading.java revision 11707:ad7af1afda7a 
1/*
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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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).
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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.
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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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
42package compiler.classUnloading.methodUnloading;
43
44import sun.hotspot.WhiteBox;
45
46import java.lang.reflect.Method;
47import java.net.URL;
48import java.net.URLClassLoader;
49
50public 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}
156