--- /dev/null 2019-02-07 20:54:51.336000000 +0300 +++ new/test/jdk/jfr/event/oldobject/TestMetadataRetention.java 2019-02-08 18:33:34.628120398 +0300 @@ -0,0 +1,189 @@ +/* + * Copyright (c) 2017, 2018, 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.event.oldobject; + +import java.time.Instant; +import java.util.List; + +import jdk.jfr.Event; +import jdk.jfr.Recording; +import jdk.jfr.consumer.RecordedClass; +import jdk.jfr.consumer.RecordedClassLoader; +import jdk.jfr.consumer.RecordedEvent; +import jdk.jfr.consumer.RecordedFrame; +import jdk.jfr.consumer.RecordedStackTrace; +import jdk.jfr.consumer.RecordedThread; +import jdk.jfr.internal.test.WhiteBox; +import jdk.test.lib.Asserts; +import jdk.test.lib.jfr.EventNames; +import jdk.test.lib.jfr.Events; +import jdk.test.lib.jfr.TestClassLoader; + +/** + * @test + * @summary The test verifies that an old object sample maintains references to "stale" metadata + * + * + * @key jfr + * + * @library /lib / + * @build jdk.jfr.event.oldobject.TestMetadataObject + * @run main/othervm -XX:TLABSize=2k -Xmx16m jdk.jfr.event.oldobject.TestMetadataRetention + */ +public final class TestMetadataRetention { + private final static String TEST_PACKAGE = TestMetadataRetention.class.getPackage().getName(); + private final static String TEST_CLASS_LOADER_NAME = "jdk/test/lib/jfr/TestClassLoader"; // see TestClassLoader.java, was "JFR TestClassLoader"; + private final static String TEST_CLASS_NAME = TEST_PACKAGE + ".TestMetadataObject"; + private final static String ALLOCATOR_THREAD_NAME = "TestAllocationThread"; + + public static ClassLoader testClassLoader; + public static Object leakObject; + public static Thread allocatorThread; + public static Class testClass; + + static class ChunkRotation extends Event { + } + + public static void main(String[] args) throws Throwable { + WhiteBox.setWriteAllObjectSamples(true); + int failedAttempts = 0; + while (true) { + try (Recording recording = new Recording()) { + recording.enable(EventNames.OldObjectSample).withStackTrace(); + recording.enable(EventNames.ClassUnload); + recording.start(); + + // Setup metadata on the Java heap (class, stack trace and thread) + testClassLoader = new TestClassLoader(); + testClass = testClassLoader.loadClass(TEST_CLASS_NAME); + allocatorThread = new Thread(TestMetadataRetention::allocateLeak, ALLOCATOR_THREAD_NAME); + allocatorThread.start(); + allocatorThread.join(); + + // Clear out metadata on the heap + testClassLoader = null; + testClass = null; + allocatorThread = null; + + // 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 CMS will not guarantee that all semantically dead classes will be + // unloaded. As far as the "jfr" key guarantees no VM flags are set from the + // outside it should be enough with System.gc(). + System.gc(); + + // Provoke a chunk rotation, which will flush out ordinary metadata. + provokeChunkRotation(); + ChunkRotation cr = new ChunkRotation(); + cr.commit(); + recording.stop(); + + List events = Events.fromRecording(recording); + RecordedEvent chunkRotation = findChunkRotationEvent(events); + try { + // Sanity check that class was unloaded + Events.hasEvent(recording, EventNames.ClassUnload); + validateClassUnloadEvent(events); + // Validate that metadata for old object event has survived chunk rotation + Events.hasEvent(recording, EventNames.OldObjectSample); + validateOldObjectEvent(events, chunkRotation.getStartTime()); + } catch (Throwable t) { + t.printStackTrace(); + System.err.println("Number of failed attempts " + ++failedAttempts); + continue; + } + break; + } + } + } + + private static RecordedEvent findChunkRotationEvent(List events) { + for (RecordedEvent e : events) { + if (e.getEventType().getName().equals(ChunkRotation.class.getName())) { + return e; + } + } + Asserts.fail("Could not find chunk rotation event"); + return null; // Can't happen; + } + + private static void allocateLeak() { + try { + leakObject = testClass.getMethod("startRecurse").invoke(null); + } catch (Exception e) { + System.out.println("Could not allocate memory leak!"); + e.printStackTrace(); + } + } + + private static void provokeChunkRotation() { + try (Recording r = new Recording()) { + r.start(); + r.stop(); + } + } + + private static void validateClassUnloadEvent(List events) throws Throwable { + for (RecordedEvent event : events) { + if (event.getEventType().getName().equals(EventNames.ClassUnload)) { + RecordedClass unloadedClass = event.getValue("unloadedClass"); + if (TEST_CLASS_NAME.equals(unloadedClass.getName())) { + RecordedClassLoader definingClassLoader = unloadedClass.getClassLoader(); + Asserts.assertEquals(TEST_CLASS_LOADER_NAME, definingClassLoader.getName(), "Expected " + TEST_CLASS_LOADER_NAME + ", got " + definingClassLoader.getType().getName()); + return; + } + } + } + } + + private static void validateOldObjectEvent(List events, Instant chunkRotation) throws Throwable { + for (RecordedEvent event : events) { + if (event.getEventType().getName().equals(EventNames.OldObjectSample)) { + // Only check event after the rotation + if (!event.getStartTime().isBefore(chunkRotation)) { + System.out.println(event); + RecordedThread rt = event.getThread(); + if (rt.getJavaName().equals(ALLOCATOR_THREAD_NAME)) { + RecordedStackTrace s = event.getStackTrace(); + assertStackTrace(s, "startRecurse"); + assertStackTrace(s, "recurse"); + return; + } + } + } + } + + Asserts.fail("Did not find an old object event with thread " + ALLOCATOR_THREAD_NAME); + } + + private static void assertStackTrace(RecordedStackTrace stacktrace, final String methodName) { + for (RecordedFrame f : stacktrace.getFrames()) { + if (f.getMethod().getName().equals(methodName)) { + return; + } + } + Asserts.fail("Could not find class " + methodName + " in stack trace " + stacktrace); + } +}