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. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 */ 23 24 package jdk.jfr.event.allocation; 25 26 import static java.lang.Math.floor; 27 28 import jdk.jfr.Recording; 29 import jdk.jfr.consumer.RecordedEvent; 30 import jdk.test.lib.jfr.EventNames; 31 import jdk.test.lib.jfr.Events; 32 import jdk.test.lib.Asserts; 33 34 /** 35 * @test 36 * @summary Test that event is triggered when an object is allocated in a new TLAB. 37 * @key jfr 38 * @requires vm.hasJFR 39 * @library /test/lib 40 * @run main/othervm -XX:+UseTLAB -XX:TLABSize=100k -XX:-ResizeTLAB -XX:TLABRefillWasteFraction=1 jdk.jfr.event.allocation.TestObjectAllocationInNewTLABEvent 41 * @run main/othervm -XX:+UseTLAB -XX:TLABSize=100k -XX:-ResizeTLAB -XX:TLABRefillWasteFraction=1 -Xint jdk.jfr.event.allocation.TestObjectAllocationInNewTLABEvent 42 */ 43 44 /** 45 * Test that when an object is allocated in a new Thread Local Allocation Buffer (TLAB) 46 * an event will be triggered. The test is done for default and interpreted mode (-Xint). 47 * 48 * To force objects to be allocated in a new TLAB: 49 * the size of TLAB is set to 100k (-XX:TLABSize=100k); 50 * the size of allocated objects is set to 100k minus 16 bytes overhead; 51 * max TLAB waste at refill is set to minimum (-XX:TLABRefillWasteFraction=1), 52 * to provoke a new TLAB creation. 53 */ 54 public class TestObjectAllocationInNewTLABEvent { 55 private final static String EVENT_NAME = EventNames.ObjectAllocationInNewTLAB; 56 57 private static final int BYTE_ARRAY_OVERHEAD = 16; // Extra bytes used by a byte array. 58 private static final int OBJECT_SIZE = 100 * 1024; 59 private static final int OBJECT_SIZE_ALT = OBJECT_SIZE + 8; // Object size in case of disabled CompressedOops. 60 private static final int OBJECTS_TO_ALLOCATE = 100; 61 private static final String BYTE_ARRAY_CLASS_NAME = new byte[0].getClass().getName(); 62 private static final int INITIAL_TLAB_SIZE = 100 * 1024; 63 private static int countAllTlabs; // Count all matching tlab allocations. 64 private static int countFullTlabs; // Count matching tlab allocations with full tlab size. 65 66 // Make sure allocation isn't dead code eliminated. 67 public static byte[] tmp; 68 main(String[] args)69 public static void main(String[] args) throws Exception { 70 Recording recording = new Recording(); 71 recording.enable(EVENT_NAME); 72 recording.start(); 73 System.gc(); 74 allocate(); 75 recording.stop(); 76 verifyRecording(recording); 77 int minCount = (int) floor(OBJECTS_TO_ALLOCATE * 0.80); 78 Asserts.assertGreaterThanOrEqual(countAllTlabs, minCount, "Too few tlab objects allocated"); 79 Asserts.assertLessThanOrEqual(countAllTlabs, OBJECTS_TO_ALLOCATE, "Too many tlab objects allocated"); 80 81 // For most GCs we expect the size of each tlab to be 82 // INITIAL_TLAB_SIZE + ALLOCATION_SIZE, but that is not always true for G1. 83 // G1 may use a smaller tlab size if the full tlab does not fit in the 84 // selected memory region. 85 // 86 // For example, if a G1 memory region has room for 4.7 tlabs, 87 // then the first 4 tlabs will have the expected size, 88 // but the fifth tlab would only have a size of 0.7*expected. 89 // 90 // It is only the last tlab in each region that has a smaller size. 91 // This means that at least 50% of the allocated tlabs should 92 // have the expected size (1 full tlab, and 1 fractional tlab). 93 Asserts.assertGreaterThanOrEqual(2*countFullTlabs, countAllTlabs, "Too many fractional tlabs."); 94 } 95 allocate()96 private static void allocate() { 97 for (int i = 0; i < OBJECTS_TO_ALLOCATE; ++i) { 98 tmp = new byte[OBJECT_SIZE - BYTE_ARRAY_OVERHEAD]; 99 } 100 } 101 verifyRecording(Recording recording)102 private static void verifyRecording(Recording recording) throws Exception { 103 for (RecordedEvent event : Events.fromRecording(recording)) { 104 verify(event); 105 } 106 } 107 verify(RecordedEvent event)108 private static void verify(RecordedEvent event) { 109 if (Thread.currentThread().getId() != event.getThread().getJavaThreadId()) { 110 return; 111 } 112 long allocationSize = Events.assertField(event, "allocationSize").atLeast(1L).getValue(); 113 long tlabSize = Events.assertField(event, "tlabSize").atLeast(allocationSize).getValue(); 114 String className = Events.assertField(event, "objectClass.name").notEmpty().getValue(); 115 if (className.equals(BYTE_ARRAY_CLASS_NAME) && (allocationSize == OBJECT_SIZE || allocationSize == OBJECT_SIZE_ALT)) { 116 countAllTlabs++; 117 if (tlabSize == INITIAL_TLAB_SIZE + OBJECT_SIZE || tlabSize == INITIAL_TLAB_SIZE + OBJECT_SIZE_ALT) { 118 countFullTlabs++; 119 } 120 } 121 } 122 } 123