--- /dev/null 2017-11-09 09:38:01.297999907 +0100 +++ new/test/jdk/jdk/jfr/event/runtime/TestBiasedLockRevocationEvents.java 2018-04-09 18:25:25.528726736 +0200 @@ -0,0 +1,312 @@ +/* + * 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.runtime; + +import jdk.jfr.Recording; +import jdk.jfr.consumer.*; +import jdk.test.lib.Asserts; +import jdk.test.lib.dcmd.PidJcmdExecutor; +import jdk.test.lib.jfr.EventNames; +import jdk.test.lib.jfr.Events; +import jdk.test.lib.process.OutputAnalyzer; + +import java.util.HashMap; +import java.util.List; +import java.util.concurrent.FutureTask; + +/* + * @test + * @key jfr + * @library /test/lib + * + * @run main/othervm jdk.jfr.event.runtime.TestBiasedLockRevocationEvents + */ +public class TestBiasedLockRevocationEvents { + + public static void main(String[] args) throws Throwable { + testSingleRevocation(); + testBulkRevocation(); + testSelfRevocation(); + testExitedThreadRevocation(); + testBulkRevocationNoRebias(); + testRevocationSafepointIdCorrelation(); + } + + // Default value of BiasedLockingBulkRebiasThreshold is 20, and BiasedLockingBulkRevokeTreshold is 40. + // Using a value that will hit the first threshold once, and the second one the next time. + private static final int BULK_REVOKE_THRESHOLD = 25; + + static void touch(Object lock) { + synchronized(lock) { + } + } + + static Thread triggerRevocation(int numRevokes, Class lockClass) throws Throwable { + Object[] locks = new Object[numRevokes]; + for (int i = 0; i < locks.length; ++i) { + locks[i] = lockClass.getDeclaredConstructor().newInstance(); + touch(locks[i]); + } + + Thread biasBreaker = new Thread("BiasBreaker") { + @Override + public void run() { + for (Object lock : locks) { + touch(lock); + } + } + }; + + biasBreaker.start(); + biasBreaker.join(); + + return biasBreaker; + } + + // Basic stack trace validation, checking the name of the leaf method + static void validateStackTrace(RecordedStackTrace stackTrace, String leafMethodName) { + List frames = stackTrace.getFrames(); + Asserts.assertFalse(frames.isEmpty()); + String name = frames.get(0).getMethod().getName(); + Asserts.assertEquals(name, leafMethodName); + } + + // Validates that the given stack trace refers to lock.touch(); in triggerRevocation + static void validateStackTrace(RecordedStackTrace stackTrace) { + validateStackTrace(stackTrace, "touch"); + } + + static void testSingleRevocation() throws Throwable { + class MyLock {}; + + Recording recording = new Recording(); + + recording.enable(EventNames.BiasedLockRevocation); + recording.start(); + + Thread biasBreaker = triggerRevocation(1, MyLock.class); + + recording.stop(); + + List events = Events.fromRecording(recording); + + // We may or may not catch a second revocation from the biasBreaker thread exiting + Asserts.assertGreaterThanOrEqual(events.size(), 1); + + RecordedEvent event = events.get(0); + Events.assertEventThread(event, biasBreaker); + Events.assertEventThread(event, "previousOwner", Thread.currentThread()); + + RecordedClass lockClass = event.getValue("lockClass"); + Asserts.assertEquals(lockClass.getName(), MyLock.class.getName()); + + validateStackTrace(event.getStackTrace()); + } + + static void testBulkRevocation() throws Throwable { + class MyLock {}; + + Recording recording = new Recording(); + + recording.enable(EventNames.BiasedLockClassRevocation); + recording.start(); + + Thread biasBreaker = triggerRevocation(BULK_REVOKE_THRESHOLD, MyLock.class); + + recording.stop(); + List events = Events.fromRecording(recording); + Asserts.assertEQ(events.size(), 1); + + RecordedEvent event = events.get(0); + Events.assertEventThread(event, biasBreaker); + Events.assertField(event, "disableBiasing").equal(false); + + RecordedClass lockClass = event.getValue("revokedClass"); + Asserts.assertEquals(lockClass.getName(), MyLock.class.getName()); + + validateStackTrace(event.getStackTrace()); + } + + static void testSelfRevocation() throws Throwable { + class MyLock {}; + + Recording recording = new Recording(); + + recording.enable(EventNames.BiasedLockSelfRevocation); + recording.start(); + + MyLock l = new MyLock(); + touch(l); + Thread.holdsLock(l); + + recording.stop(); + + List events = Events.fromRecording(recording); + Asserts.assertEQ(events.size(), 1); + + RecordedEvent event = events.get(0); + Events.assertEventThread(event, Thread.currentThread()); + + validateStackTrace(event.getStackTrace(), "holdsLock"); + } + + static void testExitedThreadRevocation() throws Throwable { + class MyLock {}; + + Recording recording = new Recording(); + + recording.enable(EventNames.BiasedLockRevocation); + recording.start(); + + FutureTask lockerTask = new FutureTask<>(() -> { + MyLock l = new MyLock(); + touch(l); + return l; + }); + + Thread locker = new Thread(lockerTask, "BiasLocker"); + locker.start(); + locker.join(); + + // Even after joining, the VM has a bit more work to do before the thread is actually removed + // from the threads list. Ensure that this has happened before proceeding. + while (true) { + PidJcmdExecutor jcmd = new PidJcmdExecutor(); + OutputAnalyzer oa = jcmd.execute("Thread.print", true); + String lockerThreadFound = oa.firstMatch("BiasLocker"); + if (lockerThreadFound == null) { + break; + } + }; + + MyLock l = lockerTask.get(); + touch(l); + + recording.stop(); + List events = Events.fromRecording(recording); + Events.hasEvents(events); + + // Joining the locker thread can cause revocations as well, search for the interesting one + for (RecordedEvent event : events) { + RecordedClass lockClass = event.getValue("lockClass"); + if (lockClass.getName().equals(MyLock.class.getName())) { + Events.assertEventThread(event, Thread.currentThread()); + // Previous owner will usually be null, but can also be a thread that + // was created after the BiasLocker thread exited due to address reuse. + RecordedThread prevOwner = event.getValue("previousOwner"); + if (prevOwner != null) { + Asserts.assertNE(prevOwner.getJavaName(), "BiasLocker"); + } + validateStackTrace(event.getStackTrace()); + return; + } + } + Asserts.fail("Did not find any revocation event for MyLock"); + } + + static void testBulkRevocationNoRebias() throws Throwable { + class MyLock {}; + + Recording recording = new Recording(); + + recording.enable(EventNames.BiasedLockClassRevocation); + recording.start(); + + Thread biasBreaker0 = triggerRevocation(BULK_REVOKE_THRESHOLD, MyLock.class); + Thread biasBreaker1 = triggerRevocation(BULK_REVOKE_THRESHOLD, MyLock.class); + + recording.stop(); + List events = Events.fromRecording(recording); + Asserts.assertEQ(events.size(), 2); + + RecordedEvent eventRebias = events.get(0); + Events.assertEventThread(eventRebias, biasBreaker0); + Events.assertField(eventRebias, "disableBiasing").equal(false); + + RecordedEvent eventNoRebias = events.get(1); + Events.assertEventThread(eventNoRebias, biasBreaker1); + Events.assertField(eventNoRebias, "disableBiasing").equal(true); + + RecordedClass lockClassRebias = eventRebias.getValue("revokedClass"); + Asserts.assertEquals(lockClassRebias.getName(), MyLock.class.getName()); + RecordedClass lockClassNoRebias = eventNoRebias.getValue("revokedClass"); + Asserts.assertEquals(lockClassNoRebias.getName(), MyLock.class.getName()); + + validateStackTrace(eventRebias.getStackTrace()); + validateStackTrace(eventNoRebias.getStackTrace()); + } + + static void testRevocationSafepointIdCorrelation() throws Throwable { + class MyLock {}; + + Recording recording = new Recording(); + + recording.enable(EventNames.BiasedLockRevocation); + recording.enable(EventNames.BiasedLockClassRevocation); + recording.enable(EventNames.ExecuteVMOperation); + recording.start(); + + triggerRevocation(BULK_REVOKE_THRESHOLD, MyLock.class); + + recording.stop(); + List events = Events.fromRecording(recording); + + // Find all biased locking related VMOperation events + HashMap vmOperations = new HashMap(); + for (RecordedEvent event : events) { + if ((event.getEventType().getName().equals(EventNames.ExecuteVMOperation)) && + (event.getValue("operation").toString().contains("Bias"))) { + vmOperations.put(event.getValue("safepointId"), event); + } + } + + int revokeCount = 0; + int bulkRevokeCount = 0; + + // Match all revoke events to a corresponding VMOperation event + for (RecordedEvent event : events) { + if (event.getEventType().getName().equals(EventNames.BiasedLockRevocation)) { + RecordedEvent vmOpEvent = vmOperations.remove(event.getValue("safepointId")); + if (event.getValue("safepointId").toString().equals("-1")) { + Asserts.assertEquals(vmOpEvent, null); + } else { + Events.assertField(vmOpEvent, "operation").equal("RevokeBias"); + revokeCount++; + } + } else if (event.getEventType().getName().equals(EventNames.BiasedLockClassRevocation)) { + RecordedEvent vmOpEvent = vmOperations.remove(event.getValue("safepointId")); + Events.assertField(vmOpEvent, "operation").equal("BulkRevokeBias"); + bulkRevokeCount++; + } + } + + // All VMOperations should have had a matching revoke event + Asserts.assertEQ(vmOperations.size(), 0); + + Asserts.assertGT(bulkRevokeCount, 0); + Asserts.assertGT(revokeCount, bulkRevokeCount); + } +}