1 /* 2 * Copyright (c) 2015, 2021, 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 gc.g1.humongousObjects; 25 26 import gc.testlibrary.Helpers; 27 import jdk.test.lib.Asserts; 28 import sun.hotspot.WhiteBox; 29 30 import java.lang.ref.Reference; 31 import java.lang.ref.ReferenceQueue; 32 import java.lang.ref.SoftReference; 33 import 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 jdk.test.lib.helpers.ClassFileInstaller sun.hotspot.WhiteBox 45 * 46 * @run main/othervm -XX:+UseG1GC -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions 47 * -XX:+WhiteBoxAPI -Xbootclasspath/a:. -Xms200m -Xmx200m -Xlog:gc 48 * -XX:InitiatingHeapOccupancyPercent=100 -XX:G1HeapRegionSize=1M -Xlog:gc=info:file=TestObjectCollected.gc.log 49 * gc.g1.humongousObjects.TestObjectCollected 50 */ 51 52 53 /** 54 * Test checks that after different type of GCs weak/soft references to humongous object behave correspondingly to 55 * actual object behavior. 56 * So if object was collected, reference.get() should return null and vice versa 57 * Since we check humongous objects after such an object is collected the region where it was allocated becomes free 58 * or/and change type to non-humongous. Two WhiteBox method were used - first returns if a region containing certain 59 * address is free and second - if a region containing certain address is humongous 60 */ 61 62 public class TestObjectCollected { 63 /** 64 * Provides methods to initiate GC of requested type 65 */ 66 private enum GC { 67 YOUNG_CG { 68 @Override provoke()69 public void provoke() { 70 WHITE_BOX.youngGC(); 71 } 72 }, 73 FULL_GC { 74 @Override provoke()75 public void provoke() { 76 System.gc(); 77 } 78 }, 79 CMC { 80 @Override provoke()81 public void provoke() { 82 Helpers.waitTillCMCFinished(WHITE_BOX, 0); 83 WHITE_BOX.g1StartConcMarkCycle(); 84 Helpers.waitTillCMCFinished(WHITE_BOX, 0); 85 } 86 }, 87 FULL_GC_MEMORY_PRESSURE { 88 @Override provoke()89 public void provoke() { 90 WHITE_BOX.fullGC(); 91 } 92 }; 93 private static final WhiteBox WHITE_BOX = WhiteBox.getWhiteBox(); 94 provoke()95 public abstract void provoke(); 96 } 97 98 /** 99 * Factory for weak and soft references. 100 * Allocates byte array of ALLOCATION_SIZE and returns weak/soft reference on it. 101 */ 102 private enum REF_FACTORY { 103 WEAK { 104 @Override create()105 public Reference<byte[]> create() { 106 return new WeakReference<>(new byte[ALLOCATION_SIZE], referenceQueqe); 107 } 108 }, 109 SOFT { 110 @Override create()111 public Reference<byte[]> create() { 112 return new SoftReference<>(new byte[ALLOCATION_SIZE], referenceQueqe); 113 } 114 }; 115 116 private static final ReferenceQueue<byte[]> referenceQueqe = new ReferenceQueue<>(); 117 private static final int ALLOCATION_SIZE = WhiteBox.getWhiteBox().g1RegionSize() * 2 / 3; 118 119 /** 120 * Factory method 121 * 122 * @return weak/soft reference on byte array of ALLOCATION_SIZE 123 */ create()124 public abstract Reference<byte[]> create(); 125 } 126 127 128 private static final WhiteBox WHITE_BOX = WhiteBox.getWhiteBox(); 129 130 /** 131 * Does actual testing: 132 * Gets a reference 133 * Gets address of referenced object using WB method 134 * Calls gc of provided type 135 * Checks that object was/was not deleted using WB methods. 136 */ doTesting(GC gc, REF_FACTORY ref)137 public static void doTesting(GC gc, REF_FACTORY ref) { 138 139 System.out.println(String.format("Testing %s reference behavior after %s", ref.name(), gc.name())); 140 141 Reference<byte[]> reference = ref.create(); 142 Asserts.assertNotNull(reference, "Test Bug: failed to allocate reference"); 143 long adr = WHITE_BOX.getObjectAddress(reference.get()); 144 145 //Sanity checks 146 boolean isRefNulled = (reference.get() == null); 147 boolean isRegionHumongous = WHITE_BOX.g1BelongsToHumongousRegion(adr); 148 boolean isRegionFree = WHITE_BOX.g1BelongsToFreeRegion(adr); 149 150 151 Asserts.assertEquals(isRefNulled, false, 152 "We just allocated an object but reference.get() already returned null"); 153 154 Asserts.assertEquals(isRegionFree, false, 155 "We just allocated an object but WB returns that allocation region is still considered free"); 156 157 Asserts.assertEquals(isRegionHumongous, true, 158 "We just allocated a humongous object but WB returns that allocation region is not humongous"); 159 160 gc.provoke(); 161 162 isRefNulled = (reference.get() == null); 163 isRegionHumongous = WHITE_BOX.g1BelongsToHumongousRegion(adr); 164 isRegionFree = WHITE_BOX.g1BelongsToFreeRegion(adr); 165 166 boolean isObjCollected = isRegionFree || !isRegionHumongous; 167 168 Asserts.assertEquals(isRefNulled, isObjCollected, 169 String.format("There is an inconsistensy between reference and white box " 170 + "method behavior - one considers object referenced with " 171 + "%s type collected and another doesn't!\n" 172 + "\treference.get() returned %snull\n" 173 + "\tWhiteBox methods returned that object was%s collected", 174 reference.getClass().getSimpleName(), 175 (isRefNulled ? "" : "not "), 176 (isObjCollected ? "" : " not"))); 177 178 System.out.println("Passed"); 179 } 180 181 /** 182 * Entry point 183 * 184 * @param args not used 185 */ main(String[] args)186 public static void main(String[] args) { 187 // Full gc - System.gc() 188 TestObjectCollected.doTesting(GC.FULL_GC, REF_FACTORY.WEAK); 189 TestObjectCollected.doTesting(GC.FULL_GC, REF_FACTORY.SOFT); 190 191 // Full gc with memory pressure - WB.fullGC() emulates that no memory left 192 TestObjectCollected.doTesting(GC.FULL_GC_MEMORY_PRESSURE, REF_FACTORY.WEAK); 193 TestObjectCollected.doTesting(GC.FULL_GC_MEMORY_PRESSURE, REF_FACTORY.SOFT); 194 195 // Young gc 196 TestObjectCollected.doTesting(GC.YOUNG_CG, REF_FACTORY.WEAK); 197 TestObjectCollected.doTesting(GC.YOUNG_CG, REF_FACTORY.SOFT); 198 199 // Concurrent mark cycle 200 TestObjectCollected.doTesting(GC.CMC, REF_FACTORY.WEAK); 201 TestObjectCollected.doTesting(GC.CMC, REF_FACTORY.SOFT); 202 } 203 } 204