| /* |
| * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package jdk.jfr.jvm; |
| |
| import java.time.Duration; |
| import java.util.List; |
| |
| import jdk.jfr.consumer.RecordedClass; |
| import jdk.jfr.consumer.RecordedClassLoader; |
| import jdk.jfr.consumer.RecordedEvent; |
| import jdk.jfr.internal.JVM; |
| import jdk.jfr.Recording; |
| import jdk.test.lib.Asserts; |
| import jdk.test.lib.jfr.EventNames; |
| import jdk.test.lib.jfr.Events; |
| import jdk.test.lib.jfr.TestClassLoader; |
| |
| /** |
| * @test |
| * @bug 8231081 |
| * @key jfr |
| * @requires vm.hasJFR |
| * @modules jdk.jfr/jdk.jfr.internal |
| * @library /test/lib /test/jdk |
| * @run main/othervm -Xlog:class+unload -Xlog:gc -Xmx16m jdk.jfr.jvm.TestClearStaleConstants |
| */ |
| |
| /** |
| * System.gc() will trigger class unloading if -XX:+ExplicitGCInvokesConcurrent is NOT set. |
| * If this flag is set G1 will never unload classes on System.gc() and |
| * As far as the "jfr" key guarantees no VM flags are set from the outside |
| * it should be enough with System.gc(). |
| */ |
| public final class TestClearStaleConstants { |
| static class MyClass { |
| } |
| private final static String TEST_CLASS_NAME = "jdk.jfr.jvm.TestClearStaleConstants$MyClass"; |
| private final static String EVENT_NAME = EventNames.ClassDefine; |
| |
| // to prevent the compiler to optimize away all unread writes |
| public static TestClassLoader firstClassLoader; |
| public static TestClassLoader secondClassLoader; |
| |
| public static void main(String... args) throws Exception { |
| firstClassLoader = new TestClassLoader(); |
| // define a class using a class loader under a recording |
| Class<?> clz = recordClassDefinition(firstClassLoader); |
| JVM jvm = JVM.getJVM(); |
| // we will now tag the defined and loaded clz as being in use (no recordings are running here) |
| jvm.getClassIdNonIntrinsic(clz); |
| // null out for unload to occur |
| firstClassLoader = null; |
| clz = null; |
| // provoke unload |
| System.gc(); |
| // try to define another class _with the same name_ using a different class loader |
| secondClassLoader = new TestClassLoader(); |
| // this will throw a NPE for 8231081 because it will reuse the same class name |
| // that symbol was marked as already serialized by the unload, but since no recordings were running |
| // it was not written to any chunk. This creates a reference to a non-existing symbol, leading to an NPE (no symbol at the expected location). |
| recordClassDefinition(secondClassLoader); |
| } |
| |
| private static Class<?> recordClassDefinition(TestClassLoader classLoader) throws Exception { |
| try (Recording recording = new Recording()) { |
| recording.enable(EVENT_NAME); |
| recording.start(); |
| Class<?> clz = classLoader.loadClass(TEST_CLASS_NAME); |
| recording.stop(); |
| assertClassDefineEvent(recording); |
| return clz; |
| } |
| } |
| |
| private static void assertClassDefineEvent(Recording recording) throws Exception { |
| boolean isAnyFound = false; |
| for (RecordedEvent event : Events.fromRecording(recording)) { |
| System.out.println(event); |
| RecordedClass definedClass = event.getValue("definedClass"); |
| if (TEST_CLASS_NAME.equals(definedClass.getName())) { |
| RecordedClassLoader definingClassLoader = definedClass.getClassLoader(); |
| String definingName = definingClassLoader.getType().getName(); |
| String testName = TestClassLoader.class.getName(); |
| String errorMsg = "Expected " + testName + ", got " + definingName; |
| Asserts.assertEquals(testName, definingName, errorMsg); |
| Asserts.assertFalse(isAnyFound, "Found more than 1 event"); |
| isAnyFound = true; |
| } |
| } |
| Asserts.assertTrue(isAnyFound, "No events found"); |
| } |
| } |