1 /* 2 * Copyright (c) 2015, 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 25 package gc.g1.humongousObjects; 26 27 import gc.testlibrary.Helpers; 28 import jdk.test.lib.Asserts; 29 import jdk.test.lib.Utils; 30 import sun.hotspot.WhiteBox; 31 32 import java.io.PrintStream; 33 import java.math.BigInteger; 34 import java.util.ArrayList; 35 import java.util.List; 36 import java.util.Random; 37 import java.util.stream.Collectors; 38 39 /** 40 * @test TestHumongousMovement 41 * @summary Checks that Humongous objects are not moved during GC 42 * @requires vm.gc=="G1" | vm.gc=="null" 43 * @library /testlibrary /test/lib / 44 * @modules java.management 45 * @build sun.hotspot.WhiteBox 46 * gc.testlibrary.Helpers 47 * gc.g1.humongousObjects.TestHumongousMovement 48 * @run driver ClassFileInstaller sun.hotspot.WhiteBox 49 * sun.hotspot.WhiteBox$WhiteBoxPermission 50 * @run main/othervm -XX:+UseG1GC -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI -Xbootclasspath/a:. 51 * -XX:G1HeapRegionSize=1M -Xms200m -Xmx200m -XX:InitiatingHeapOccupancyPercent=100 52 * -Xlog:gc=info:file=TestHumongousMovement.log 53 * gc.g1.humongousObjects.TestHumongousMovement 54 */ 55 56 public class TestHumongousMovement { 57 58 private static class AllocationData { 59 private final byte[] allocation; 60 public final BigInteger objectAddress; 61 62 public AllocationData(byte[] allocation) { 63 this.allocation = allocation; 64 this.objectAddress = new BigInteger(Long.toUnsignedString((WB.getObjectAddress(this.allocation)))); 65 } 66 67 public boolean isAddressChanged() { 68 return !new BigInteger(Long.toUnsignedString((WB.getObjectAddress(this.allocation)))).equals(objectAddress); 69 } 70 71 public void printDetails(PrintStream out) { 72 BigInteger objectAddressAfterGC = 73 new BigInteger(Long.toUnsignedString((WB.getObjectAddress(this.allocation)))); 74 75 out.println(String.format("Object stored address = %d\nObject address after GC = %d\n" 76 + "They are %sequals", objectAddress, 77 objectAddressAfterGC, !objectAddress.equals(objectAddressAfterGC) ? "not " : "")); 78 } 79 80 } 81 82 private static final WhiteBox WB = WhiteBox.getWhiteBox(); 83 84 // How many allocated humongous objects should be deleted 85 private static final double HUMONGOUS_OBJECTS_DELETED_FACTOR = 0.5D; 86 // How many of free g1 regions should be used for humongous allocations 87 private static final double ALLOCATED_HUMONGOUS_REGIONS_FACTOR = 0.25D; 88 89 public static void main(String[] args) { 90 91 int g1RegionSize = WB.g1RegionSize(); 92 int byteArrayMemoryOverhead = Helpers.detectByteArrayAllocationOverhead(); 93 94 System.out.println("Total " + WB.g1NumMaxRegions() + " regions"); 95 System.out.println("Total " + WB.g1NumFreeRegions() + " free regions"); 96 97 int regionsToAllocate = (int) (WB.g1NumFreeRegions() * ALLOCATED_HUMONGOUS_REGIONS_FACTOR); 98 99 // Sanity check 100 Asserts.assertGreaterThan(regionsToAllocate, 0, "Test Bug: no regions to allocate"); 101 102 System.out.println("Allocating " + regionsToAllocate + " humongous objects, each 90% of g1 region size"); 103 104 List<AllocationData> allocations = new ArrayList<>(); 105 106 // 90 % of maximum byte[] that takes one region 107 int hSize = (int) ((g1RegionSize - byteArrayMemoryOverhead) * 0.9); 108 109 // Sanity check 110 Asserts.assertGreaterThan(hSize, g1RegionSize / 2, "Test Bug: allocation size is not humongous"); 111 112 for (int i = 0; i < regionsToAllocate; ++i) { 113 allocations.add(new AllocationData(new byte[hSize])); 114 } 115 116 Random rnd = Utils.getRandomInstance(); 117 118 int toDelete = (int) (allocations.size() * HUMONGOUS_OBJECTS_DELETED_FACTOR); 119 120 for (int i = 0; i < toDelete; ++i) { 121 allocations.remove(rnd.nextInt(allocations.size())); 122 } 123 124 WB.fullGC(); 125 126 List<AllocationData> movedObjects = allocations.stream() 127 .filter(AllocationData::isAddressChanged) 128 .collect(Collectors.toList()); 129 130 if (movedObjects.size() > 0) { 131 System.out.println("Test failed - some humongous objects moved after Full GC"); 132 movedObjects.stream().forEach(a -> a.printDetails(System.out)); 133 throw new Error("Test failed - some humongous objects moved after Full GC"); 134 } else { 135 System.out.println("Passed"); 136 } 137 } 138 }