1/* 2 * Copyright (c) 2015, 2016, 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 24package gc.g1.humongousObjects; 25 26import gc.testlibrary.Helpers; 27import jdk.test.lib.Asserts; 28import sun.hotspot.WhiteBox; 29 30import java.lang.ref.Reference; 31import java.lang.ref.ReferenceQueue; 32import java.lang.ref.SoftReference; 33import java.lang.ref.WeakReference; 34 35/** 36 * @test TestObjectCollected 37 * @summary checks that after different type of GCs weak/soft references to humongous object behave correspondingly to 38 * actual object behavior 39 * @requires vm.gc.G1 40 * @library /test/lib / 41 * @modules java.base/jdk.internal.misc 42 * @modules java.management 43 * @build sun.hotspot.WhiteBox 44 * @run driver ClassFileInstaller sun.hotspot.WhiteBox 45 * sun.hotspot.WhiteBox$WhiteBoxPermission 46 * 47 * @run main/othervm -XX:+UseG1GC -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions 48 * -XX:+WhiteBoxAPI -Xbootclasspath/a:. -Xms200m -Xmx200m -Xlog:gc 49 * -XX:InitiatingHeapOccupancyPercent=100 -XX:G1HeapRegionSize=1M -Xlog:gc=info:file=TestObjectCollected.gc.log 50 * gc.g1.humongousObjects.TestObjectCollected 51 */ 52 53 54/** 55 * Test checks that after different type of GCs weak/soft references to humongous object behave correspondingly to 56 * actual object behavior. 57 * So if object was collected, reference.get() should return null and vice versa 58 * Since we check humongous objects after such an object is collected the region where it was allocated becomes free 59 * or/and change type to non-humongous. Two WhiteBox method were used - first returns if a region containing certain 60 * address is free and second - if a region containing certain address is humongous 61 */ 62 63public class TestObjectCollected { 64 /** 65 * Provides methods to initiate GC of requested type 66 */ 67 private enum GC { 68 YOUNG_CG { 69 @Override 70 public void provoke() { 71 WHITE_BOX.youngGC(); 72 } 73 }, 74 FULL_GC { 75 @Override 76 public void provoke() { 77 System.gc(); 78 } 79 }, 80 CMC { 81 @Override 82 public void provoke() { 83 Helpers.waitTillCMCFinished(WHITE_BOX, 0); 84 WHITE_BOX.g1StartConcMarkCycle(); 85 Helpers.waitTillCMCFinished(WHITE_BOX, 0); 86 } 87 }, 88 FULL_GC_MEMORY_PRESSURE { 89 @Override 90 public void provoke() { 91 WHITE_BOX.fullGC(); 92 } 93 }; 94 private static final WhiteBox WHITE_BOX = WhiteBox.getWhiteBox(); 95 96 public abstract void provoke(); 97 } 98 99 /** 100 * Factory for weak and soft references. 101 * Allocates byte array of ALLOCATION_SIZE and returns weak/soft reference on it. 102 */ 103 private enum REF_FACTORY { 104 WEAK { 105 @Override 106 public Reference<byte[]> create() { 107 return new WeakReference<>(new byte[ALLOCATION_SIZE], referenceQueqe); 108 } 109 }, 110 SOFT { 111 @Override 112 public Reference<byte[]> create() { 113 return new SoftReference<>(new byte[ALLOCATION_SIZE], referenceQueqe); 114 } 115 }; 116 117 private static final ReferenceQueue<byte[]> referenceQueqe = new ReferenceQueue<>(); 118 private static final int ALLOCATION_SIZE = WhiteBox.getWhiteBox().g1RegionSize() * 2 / 3; 119 120 /** 121 * Factory method 122 * 123 * @return weak/soft reference on byte array of ALLOCATION_SIZE 124 */ 125 public abstract Reference<byte[]> create(); 126 } 127 128 129 private static final WhiteBox WHITE_BOX = WhiteBox.getWhiteBox(); 130 131 /** 132 * Does actual testing: 133 * Gets a reference 134 * Gets address of referenced object using WB method 135 * Calls gc of provided type 136 * Checks that object was/was not deleted using WB methods. 137 */ 138 public static void doTesting(GC gc, REF_FACTORY ref) { 139 140 System.out.println(String.format("Testing %s reference behavior after %s", ref.name(), gc.name())); 141 142 Reference reference = ref.create(); 143 Asserts.assertNotNull(reference, "Test Bug: failed to allocate reference"); 144 long adr = WHITE_BOX.getObjectAddress(reference.get()); 145 146 //Sanity checks 147 boolean isRefNulled = (reference.get() == null); 148 boolean isRegionHumongous = WHITE_BOX.g1BelongsToHumongousRegion(adr); 149 boolean isRegionFree = WHITE_BOX.g1BelongsToFreeRegion(adr); 150 151 152 Asserts.assertEquals(isRefNulled, false, 153 "We just allocated an object but reference.get() already returned null"); 154 155 Asserts.assertEquals(isRegionFree, false, 156 "We just allocated an object but WB returns that allocation region is still considered free"); 157 158 Asserts.assertEquals(isRegionHumongous, true, 159 "We just allocated a humongous object but WB returns that allocation region is not humongous"); 160 161 gc.provoke(); 162 163 isRefNulled = (reference.get() == null); 164 isRegionHumongous = WHITE_BOX.g1BelongsToHumongousRegion(adr); 165 isRegionFree = WHITE_BOX.g1BelongsToFreeRegion(adr); 166 167 boolean isObjCollected = isRegionFree || !isRegionHumongous; 168 169 Asserts.assertEquals(isRefNulled, isObjCollected, 170 String.format("There is an inconsistensy between reference and white box " 171 + "method behavior - one considers object referenced with " 172 + "%s type collected and another doesn't!\n" 173 + "\treference.get() returned %snull\n" 174 + "\tWhiteBox methods returned that object was%s collected", 175 reference.getClass().getSimpleName(), 176 (isRefNulled ? "" : "not "), 177 (isObjCollected ? "" : " not"))); 178 179 System.out.println("Passed"); 180 } 181 182 /** 183 * Entry point 184 * 185 * @param args not used 186 */ 187 public static void main(String[] args) { 188 // Full gc - System.gc() 189 TestObjectCollected.doTesting(GC.FULL_GC, REF_FACTORY.WEAK); 190 TestObjectCollected.doTesting(GC.FULL_GC, REF_FACTORY.SOFT); 191 192 // Full gc with memory pressure - WB.fullGC() emulates that no memory left 193 TestObjectCollected.doTesting(GC.FULL_GC_MEMORY_PRESSURE, REF_FACTORY.WEAK); 194 TestObjectCollected.doTesting(GC.FULL_GC_MEMORY_PRESSURE, REF_FACTORY.SOFT); 195 196 // Young gc 197 TestObjectCollected.doTesting(GC.YOUNG_CG, REF_FACTORY.WEAK); 198 TestObjectCollected.doTesting(GC.YOUNG_CG, REF_FACTORY.SOFT); 199 200 // Concurrent mark cycle 201 TestObjectCollected.doTesting(GC.CMC, REF_FACTORY.WEAK); 202 TestObjectCollected.doTesting(GC.CMC, REF_FACTORY.SOFT); 203 } 204} 205