1 /* 2 * Copyright (c) 2013, 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.event.runtime; 27 28 import java.time.Duration; 29 import java.util.List; 30 31 import jdk.jfr.Recording; 32 import jdk.jfr.consumer.RecordedClass; 33 import jdk.jfr.consumer.RecordedClassLoader; 34 import jdk.jfr.consumer.RecordedEvent; 35 import jdk.test.lib.Asserts; 36 import jdk.test.lib.jfr.EventNames; 37 import jdk.test.lib.jfr.Events; 38 import jdk.test.lib.jfr.TestClassLoader; 39 40 /** 41 * @test 42 * @summary The test verifies that a class unload event is created when class is unloaded 43 * @key jfr 44 * @requires vm.hasJFR 45 * @library /test/lib /test/jdk 46 * @build jdk.jfr.event.runtime.TestClasses 47 * @run main/othervm -Xlog:class+unload -Xlog:gc -Xmx16m jdk.jfr.event.runtime.TestClassUnloadEvent 48 */ 49 50 /** 51 * System.gc() will trigger class unloading if -XX:+ExplicitGCInvokesConcurrent is NOT set. 52 * If this flag is set G1 will never unload classes on System.gc() and 53 * CMS will not guarantee that all semantically dead classes will be unloaded. 54 * As far as the "jfr" key guarantees no VM flags are set from the outside 55 * it should be enough with System.gc(). 56 */ 57 public final class TestClassUnloadEvent { 58 private final static String TEST_CLASS_NAME = "jdk.jfr.event.runtime.TestClasses"; 59 private final static String EVENT_PATH = EventNames.ClassUnload; 60 61 // Declare unloadableClassLoader as "public static" 62 // to prevent the compiler to optimize away all unread writes 63 public static TestClassLoader unloadableClassLoader; 64 65 public static void main(String[] args) throws Throwable { 66 Recording recording = new Recording(); 67 recording.enable(EVENT_PATH).withThreshold(Duration.ofMillis(0)); 68 unloadableClassLoader = new TestClassLoader(); 69 recording.start(); 70 unloadableClassLoader.loadClass(TEST_CLASS_NAME); 71 unloadableClassLoader = null; 72 System.gc(); 73 recording.stop(); 74 75 List<RecordedEvent> events = Events.fromRecording(recording); 76 Events.hasEvents(events); 77 boolean isAnyFound = false; 78 for (RecordedEvent event : events) { 79 System.out.println("Event:" + event); 80 RecordedClass unloadedClass = event.getValue("unloadedClass"); 81 if (TEST_CLASS_NAME.equals(unloadedClass.getName())) { 82 RecordedClassLoader definingClassLoader = unloadedClass.getClassLoader(); 83 Asserts.assertEquals(TestClassLoader.class.getName(), definingClassLoader.getType().getName(), 84 "Expected " + TestClassLoader.class.getName() + ", got " + definingClassLoader.getType().getName()); 85 Asserts.assertEquals(TestClassLoader.CLASS_LOADER_NAME, definingClassLoader.getName(), 86 "Expected " + TestClassLoader.CLASS_LOADER_NAME + ", got " + definingClassLoader.getName()); 87 Asserts.assertFalse(isAnyFound, "Found more than 1 event"); 88 isAnyFound = true; 89 } 90 } 91 Asserts.assertTrue(isAnyFound, "No events found"); 92 } 93 }