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.compiler; 27 28 import static java.lang.Math.floor; 29 import static jdk.test.lib.Asserts.assertGreaterThanOrEqual; 30 import static jdk.test.lib.Asserts.assertLessThanOrEqual; 31 32 import java.time.Duration; 33 34 import jdk.jfr.Recording; 35 import jdk.jfr.consumer.RecordedEvent; 36 import jdk.test.lib.jfr.EventNames; 37 import jdk.test.lib.jfr.Events; 38 39 /** 40 * @test 41 * @summary Test that event is triggered when an object is allocated in a new TLAB. 42 * @key jfr 43 * @requires vm.hasJFR 44 * @library /test/lib 45 * @run main/othervm -XX:+UseTLAB -XX:TLABSize=100k -XX:-ResizeTLAB -XX:TLABRefillWasteFraction=1 jdk.jfr.event.compiler.TestAllocInNewTLAB 46 * @run main/othervm -XX:+UseTLAB -XX:TLABSize=100k -XX:-ResizeTLAB -XX:TLABRefillWasteFraction=1 -XX:-FastTLABRefill jdk.jfr.event.compiler.TestAllocInNewTLAB 47 * @run main/othervm -XX:+UseTLAB -XX:TLABSize=100k -XX:-ResizeTLAB -XX:TLABRefillWasteFraction=1 -Xint jdk.jfr.event.compiler.TestAllocInNewTLAB 48 */ 49 50 /** 51 * Test that when an object is allocated in a new Thread Local Allocation Buffer (TLAB) 52 * an event will be triggered. The test is done for C1-compiler, 53 * C2-compiler (-XX:-FastTLABRefill) and interpreted mode (-Xint). 54 * 55 * To force objects to be allocated in a new TLAB: 56 * the size of TLAB is set to 100k (-XX:TLABSize=100k); 57 * the size of allocated objects is set to 100k minus 16 bytes overhead; 58 * max TLAB waste at refill is set to minimum (-XX:TLABRefillWasteFraction=1), 59 * to provoke a new TLAB creation. 60 */ 61 public class TestAllocInNewTLAB { 62 private final static String EVENT_NAME = EventNames.ObjectAllocationInNewTLAB; 63 64 private static final int BYTE_ARRAY_OVERHEAD = 16; // Extra bytes used by a byte array. 65 private static final int OBJECT_SIZE = 100 * 1024; 66 private static final int OBJECT_SIZE_ALT = OBJECT_SIZE + 8; // Object size in case of disabled CompressedOops 67 private static final int OBJECTS_TO_ALLOCATE = 100; 68 private static final String BYTE_ARRAY_CLASS_NAME = new byte[0].getClass().getName(); 69 private static final int INITIAL_TLAB_SIZE = 100 * 1024; 70 71 // make sure allocation isn't dead code eliminated 72 public static byte[] tmp; 73 74 public static void main(String[] args) throws Exception { 75 Recording recording = new Recording(); 76 recording.enable(EVENT_NAME).withThreshold(Duration.ofMillis(0)); 77 78 recording.start(); 79 System.gc(); 80 for (int i = 0; i < OBJECTS_TO_ALLOCATE; ++i) { 81 tmp = new byte[OBJECT_SIZE - BYTE_ARRAY_OVERHEAD]; 82 } 83 recording.stop(); 84 85 int countAllTlabs = 0; // Count all matching tlab allocations. 86 int countFullTlabs = 0; // Count matching tlab allocations with full tlab size. 87 for (RecordedEvent event : Events.fromRecording(recording)) { 88 if (!EVENT_NAME.equals(event.getEventType().getName())) { 89 continue; 90 } 91 System.out.println("Event:" + event); 92 93 long allocationSize = Events.assertField(event, "allocationSize").atLeast(1L).getValue(); 94 long tlabSize = Events.assertField(event, "tlabSize").atLeast(allocationSize).getValue(); 95 String className = Events.assertField(event, "objectClass.name").notEmpty().getValue(); 96 97 boolean isMyEvent = Thread.currentThread().getId() == event.getThread().getJavaThreadId() 98 && className.equals(BYTE_ARRAY_CLASS_NAME) 99 && (allocationSize == OBJECT_SIZE || allocationSize == OBJECT_SIZE_ALT); 100 if (isMyEvent) { 101 countAllTlabs++; 102 if (tlabSize == INITIAL_TLAB_SIZE + OBJECT_SIZE || tlabSize == INITIAL_TLAB_SIZE + OBJECT_SIZE_ALT) { 103 countFullTlabs++; 104 } 105 } 106 } 107 108 int minCount = (int) floor(OBJECTS_TO_ALLOCATE * 0.80); 109 assertGreaterThanOrEqual(countAllTlabs, minCount, "Too few tlab objects allocated"); 110 assertLessThanOrEqual(countAllTlabs, OBJECTS_TO_ALLOCATE, "Too many tlab objects allocated"); 111 112 // For most GCs we expect the size of each tlab to be 113 // INITIAL_TLAB_SIZE + ALLOCATION_SIZE, but that is not always true for G1. 114 // G1 may use a smaller tlab size if the full tlab does not fit in the 115 // selected memory region. 116 // 117 // For example, if a G1 memory region has room for 4.7 tlabs, 118 // then the first 4 tlabs will have the expected size, 119 // but the fifth tlab would only have a size of 0.7*expected. 120 // 121 // It is only the last tlab in each region that has a smaller size. 122 // This means that at least 50% of the allocated tlabs should 123 // have the expected size (1 full tlab, and 1 fractional tlab). 124 assertGreaterThanOrEqual(2*countFullTlabs, countAllTlabs, "Too many fractional tlabs."); 125 } 126 127 }