1 /* 2 * Copyright (c) 2013, 2020, 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.allocation; 27 28 import static java.lang.Math.floor; 29 30 import jdk.jfr.Recording; 31 import jdk.jfr.consumer.RecordedEvent; 32 import jdk.test.lib.jfr.EventNames; 33 import jdk.test.lib.jfr.Events; 34 import jdk.test.lib.Asserts; 35 36 /** 37 * @test 38 * @summary Test that event is triggered when an object is allocated in a new TLAB. 39 * @key jfr 40 * @requires vm.hasJFR 41 * @library /test/lib 42 * @run main/othervm -XX:+UseTLAB -XX:TLABSize=100k -XX:-ResizeTLAB -XX:TLABRefillWasteFraction=1 jdk.jfr.event.allocation.TestObjectAllocationInNewTLABEvent 43 * @run main/othervm -XX:+UseTLAB -XX:TLABSize=100k -XX:-ResizeTLAB -XX:TLABRefillWasteFraction=1 -Xint jdk.jfr.event.allocation.TestObjectAllocationInNewTLABEvent 44 */ 45 46 /** 47 * Test that when an object is allocated in a new Thread Local Allocation Buffer (TLAB) 48 * an event will be triggered. The test is done for default and interpreted mode (-Xint). 49 * 50 * To force objects to be allocated in a new TLAB: 51 * the size of TLAB is set to 100k (-XX:TLABSize=100k); 52 * the size of allocated objects is set to 100k minus 16 bytes overhead; 53 * max TLAB waste at refill is set to minimum (-XX:TLABRefillWasteFraction=1), 54 * to provoke a new TLAB creation. 55 */ 56 public class TestObjectAllocationInNewTLABEvent { 57 private final static String EVENT_NAME = EventNames.ObjectAllocationInNewTLAB; 58 59 private static final int BYTE_ARRAY_OVERHEAD = 16; // Extra bytes used by a byte array. 60 private static final int OBJECT_SIZE = 100 * 1024; 61 private static final int OBJECT_SIZE_ALT = OBJECT_SIZE + 8; // Object size in case of disabled CompressedOops. 62 private static final int OBJECTS_TO_ALLOCATE = 100; 63 private static final String BYTE_ARRAY_CLASS_NAME = new byte[0].getClass().getName(); 64 private static final int INITIAL_TLAB_SIZE = 100 * 1024; 65 private static int countAllTlabs; // Count all matching tlab allocations. 66 private static int countFullTlabs; // Count matching tlab allocations with full tlab size. 67 68 // Make sure allocation isn't dead code eliminated. 69 public static byte[] tmp; 70 main(String[] args)71 public static void main(String[] args) throws Exception { 72 Recording recording = new Recording(); 73 recording.enable(EVENT_NAME); 74 recording.start(); 75 System.gc(); 76 allocate(); 77 recording.stop(); 78 verifyRecording(recording); 79 int minCount = (int) floor(OBJECTS_TO_ALLOCATE * 0.80); 80 Asserts.assertGreaterThanOrEqual(countAllTlabs, minCount, "Too few tlab objects allocated"); 81 Asserts.assertLessThanOrEqual(countAllTlabs, OBJECTS_TO_ALLOCATE, "Too many tlab objects allocated"); 82 83 // For most GCs we expect the size of each tlab to be 84 // INITIAL_TLAB_SIZE + ALLOCATION_SIZE, but that is not always true for G1. 85 // G1 may use a smaller tlab size if the full tlab does not fit in the 86 // selected memory region. 87 // 88 // For example, if a G1 memory region has room for 4.7 tlabs, 89 // then the first 4 tlabs will have the expected size, 90 // but the fifth tlab would only have a size of 0.7*expected. 91 // 92 // It is only the last tlab in each region that has a smaller size. 93 // This means that at least 50% of the allocated tlabs should 94 // have the expected size (1 full tlab, and 1 fractional tlab). 95 Asserts.assertGreaterThanOrEqual(2*countFullTlabs, countAllTlabs, "Too many fractional tlabs."); 96 } 97 allocate()98 private static void allocate() { 99 for (int i = 0; i < OBJECTS_TO_ALLOCATE; ++i) { 100 tmp = new byte[OBJECT_SIZE - BYTE_ARRAY_OVERHEAD]; 101 } 102 } 103 verifyRecording(Recording recording)104 private static void verifyRecording(Recording recording) throws Exception { 105 for (RecordedEvent event : Events.fromRecording(recording)) { 106 verify(event); 107 } 108 } 109 verify(RecordedEvent event)110 private static void verify(RecordedEvent event) { 111 if (Thread.currentThread().getId() != event.getThread().getJavaThreadId()) { 112 return; 113 } 114 long allocationSize = Events.assertField(event, "allocationSize").atLeast(1L).getValue(); 115 long tlabSize = Events.assertField(event, "tlabSize").atLeast(allocationSize).getValue(); 116 String className = Events.assertField(event, "objectClass.name").notEmpty().getValue(); 117 if (className.equals(BYTE_ARRAY_CLASS_NAME) && (allocationSize == OBJECT_SIZE || allocationSize == OBJECT_SIZE_ALT)) { 118 countAllTlabs++; 119 if (tlabSize == INITIAL_TLAB_SIZE + OBJECT_SIZE || tlabSize == INITIAL_TLAB_SIZE + OBJECT_SIZE_ALT) { 120 countFullTlabs++; 121 } 122 } 123 } 124 } 125