1 /* 2 * Copyright (c) 2014, 2026, 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; 25 26 /* 27 * @test TestEagerReclaimHumongousRegions 28 * @bug 8051973 29 * @summary Test to make sure that eager reclaim of humongous objects correctly works. 30 * @requires vm.gc.G1 31 * @requires vm.debug 32 * @library /test/lib /testlibrary / 33 * @modules java.base/jdk.internal.misc 34 * java.management 35 * @build jdk.test.whitebox.WhiteBox 36 * @run driver jdk.test.lib.helpers.ClassFileInstaller jdk.test.whitebox.WhiteBox 37 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -Xbootclasspath/a:. -XX:+WhiteBoxAPI gc.g1.TestEagerReclaimHumongousRegions 38 */ 39 40 import java.util.ArrayList; 41 import java.util.List; 42 import java.util.regex.Matcher; 43 import java.util.regex.MatchResult; 44 import java.util.regex.Pattern; 45 46 import jdk.test.lib.Asserts; 47 import jdk.test.lib.process.OutputAnalyzer; 48 import jdk.test.lib.process.ProcessTools; 49 import jdk.test.whitebox.WhiteBox; 50 51 public class TestEagerReclaimHumongousRegions { 52 private static final WhiteBox WB = WhiteBox.getWhiteBox(); 53 54 enum ObjectType { TYPE_ARRAY, OBJ_ARRAY } 55 enum ReferencePolicy { KEEP, DROP } 56 enum AllocationTiming { BEFORE_MARK_START, AFTER_MARK_START} 57 58 enum ExpectedState { 59 MARKED_CANDIDATE_RECLAIMED(true, true, true), 60 MARKED_CANDIDATE_NOT_RECLAIMED(true, true, false), 61 MARKED_NOTCANDIDATE_NOTRECLAIMED(true, false, false), 62 NOTMARKED_CANDIDATE_RECLAIMED(false, true, true), 63 NOTMARKED_CANDIDATE_NOTRECLAIMED(false, true, false), 64 NOTMARKED_NOTCANDIDATE_NOTRECLAIMED(false, false, false); 65 66 final boolean marked; 67 final boolean candidate; 68 final boolean reclaimed; 69 70 ExpectedState(boolean marked, boolean candidate, boolean reclaimed) { 71 this.marked = marked; 72 this.candidate = candidate; 73 this.reclaimed = reclaimed; 74 } 75 } 76 77 /** 78 * Run the helper VM, passing configuration arguments, simulating an application allocating some kind of humongous object at a 79 * point during the induced concurrent mark, and executing a young gc. 80 * 81 * @param type Whether the allocated humongous object should be a typeArray, or an objArray. 82 * @param refPolicy Drop the reference to the allocated object after reaching the given phase or keep. 83 * @param timing Allocate the humongous objects before or after reaching the given phase. 84 * @param phase The phase during concurrent mark to reach before triggering a young garbage collection. 85 * @return Returns the stdout of the VM. 86 */ 87 private static String runHelperVM(List<String> args, ObjectType type, ReferencePolicy refPolicy, AllocationTiming timing, String phase) throws Exception { 88 89 boolean useTypeArray = (type == ObjectType.TYPE_ARRAY); 90 boolean keepReference = (refPolicy == ReferencePolicy.KEEP); 91 boolean allocateAfter = (timing == AllocationTiming.AFTER_MARK_START); 92 93 args.add(TestEagerReclaimHumongousRegionsClearMarkBitsRunner.class.getName()); 94 args.add(String.valueOf(useTypeArray)); 95 args.add(String.valueOf(keepReference)); 96 args.add(String.valueOf(allocateAfter)); 97 args.add(phase); 98 99 OutputAnalyzer output = ProcessTools.executeLimitedTestJava(args); 100 101 String log = output.getStdout(); 102 System.out.println(log); 103 output.shouldHaveExitValue(0); 104 return log; 105 } 106 107 private static List<String> testArgs() throws Exception { 108 return List.of("-XX:+UseG1GC", 109 "-Xmx20M", 110 "-Xms20m", 111 "-XX:+UnlockDiagnosticVMOptions", 112 "-XX:+VerifyBeforeGC", 113 "-XX:+VerifyAfterGC", 114 "-XX:+VerifyDuringGC", 115 "-XX:+G1VerifyBitmaps", 116 "-Xbootclasspath/a:.", 117 "-Xlog:gc=debug,gc+humongous=debug", 118 "-XX:+UnlockDiagnosticVMOptions", 119 "-XX:+WhiteBoxAPI"); 120 } 121 122 private static String boolToInt(boolean value) { 123 return value ? "1" : "0"; 124 } 125 126 private static void verifyLog(String log, AllocationTiming timing, ExpectedState expected) { 127 // Find the log output indicating that the humongous object has been reclaimed, and marked and verify for the expected results. 128 // [0.351s][debug][gc,humongous] GC(3) Humongous region 2 (object size 4194320 @ 0x00000000fee00000) remset 0 code roots 0 marked 1 pinned count 0 reclaim candidate 1 type array 1 129 130 // Now check the result of the reclaim attempt. We are interested in the last such message (as mentioned above, we might get two). 131 String patternString = "gc,humongous.* marked (\\d) pin.*candidate (\\d)"; 132 Pattern pattern = Pattern.compile(patternString); 133 Matcher matcher = pattern.matcher(log); 134 135 List<MatchResult> found = new ArrayList<MatchResult>(); 136 while (matcher.find()) { 137 found.add(matcher.toMatchResult()); 138 } 139 140 Asserts.assertTrue(found.size() == 1 || found.size() == 2, "Unexpected number of log messages " + found.size()); 141 142 if (found.size() == 2) { 143 Asserts.assertTrue(timing == AllocationTiming.BEFORE_MARK_START, "Should only have two messages if allocating the object before mark start"); 144 MatchResult mr = found.removeFirst(); 145 Asserts.assertTrue(mr.group(1).equals(boolToInt(false)), "Should not be marked before mark start " + mr.group()); 146 Asserts.assertTrue(mr.group(2).equals(boolToInt(true)), "Should be candidate before mark start " + mr.group()); 147 } 148 149 MatchResult mr = found.removeFirst(); 150 Asserts.assertTrue(mr.group(1).equals(boolToInt(expected.marked)), "Expected that region was " + (expected.marked ? "" : "not ") + " marked but is " + mr.group()); 151 Asserts.assertTrue(mr.group(2).equals(boolToInt(expected.candidate)), "Expected that region was " + (expected.candidate ? "" : "not ") + " candidate but is " + mr.group()); 152 153 boolean reclaimed = Pattern.compile("Reclaimed humongous region .*").matcher(log).find(); 154 Asserts.assertTrue(expected.reclaimed == reclaimed, "Wrong log output reclaiming humongous region"); 155 } 156 157 private static void runTest(ObjectType type, 158 ReferencePolicy refPolicy, 159 AllocationTiming timing, 160 String phase, 161 ExpectedState expected) throws Exception { 162 List<String> vmArgs = testArgs(); 163 164 ArrayList<String> args = new ArrayList(vmArgs); 165 String log = runHelperVM(args, type, refPolicy, timing, phase); 166 verifyLog(log, timing, expected); 167 168 ArrayList<String> jfrArgs = new ArrayList(vmArgs); 169 jfrArgs.addLast("-XX:StartFlightRecording=settings=profile"); 170 String jfrLog = runHelperVM(jfrArgs, type, refPolicy, timing, phase); 171 verifyLog(jfrLog, timing, expected); 172 } 173 174 public static void main(String[] args) throws Exception { 175 System.out.println("Tests checking eager reclaim for when the object is allocated before mark start."); 176 runTest(ObjectType.TYPE_ARRAY, ReferencePolicy.DROP, AllocationTiming.BEFORE_MARK_START, WB.BEFORE_MARKING_COMPLETED, ExpectedState.MARKED_CANDIDATE_RECLAIMED); 177 runTest(ObjectType.TYPE_ARRAY, ReferencePolicy.DROP, AllocationTiming.BEFORE_MARK_START, WB.G1_BEFORE_REBUILD_COMPLETED, ExpectedState.MARKED_CANDIDATE_RECLAIMED); 178 runTest(ObjectType.TYPE_ARRAY, ReferencePolicy.DROP, AllocationTiming.BEFORE_MARK_START, WB.G1_BEFORE_CLEANUP_COMPLETED, ExpectedState.NOTMARKED_CANDIDATE_RECLAIMED); 179 180 runTest(ObjectType.TYPE_ARRAY, ReferencePolicy.KEEP, AllocationTiming.BEFORE_MARK_START, WB.BEFORE_MARKING_COMPLETED, ExpectedState.MARKED_CANDIDATE_NOT_RECLAIMED); 181 runTest(ObjectType.TYPE_ARRAY, ReferencePolicy.KEEP, AllocationTiming.BEFORE_MARK_START, WB.G1_BEFORE_REBUILD_COMPLETED, ExpectedState.MARKED_CANDIDATE_NOT_RECLAIMED); 182 runTest(ObjectType.TYPE_ARRAY, ReferencePolicy.KEEP, AllocationTiming.BEFORE_MARK_START, WB.G1_BEFORE_CLEANUP_COMPLETED, ExpectedState.NOTMARKED_CANDIDATE_NOTRECLAIMED); 183 184 runTest(ObjectType.OBJ_ARRAY, ReferencePolicy.DROP, AllocationTiming.BEFORE_MARK_START, WB.BEFORE_MARKING_COMPLETED, ExpectedState.MARKED_NOTCANDIDATE_NOTRECLAIMED); 185 runTest(ObjectType.OBJ_ARRAY, ReferencePolicy.DROP, AllocationTiming.BEFORE_MARK_START, WB.G1_BEFORE_REBUILD_COMPLETED, ExpectedState.MARKED_CANDIDATE_RECLAIMED); 186 runTest(ObjectType.OBJ_ARRAY, ReferencePolicy.DROP, AllocationTiming.BEFORE_MARK_START, WB.G1_BEFORE_CLEANUP_COMPLETED, ExpectedState.NOTMARKED_CANDIDATE_RECLAIMED); 187 188 runTest(ObjectType.OBJ_ARRAY, ReferencePolicy.KEEP, AllocationTiming.BEFORE_MARK_START, WB.BEFORE_MARKING_COMPLETED, ExpectedState.MARKED_NOTCANDIDATE_NOTRECLAIMED); 189 runTest(ObjectType.OBJ_ARRAY, ReferencePolicy.KEEP, AllocationTiming.BEFORE_MARK_START, WB.G1_BEFORE_REBUILD_COMPLETED, ExpectedState.MARKED_CANDIDATE_NOT_RECLAIMED); 190 runTest(ObjectType.OBJ_ARRAY, ReferencePolicy.KEEP, AllocationTiming.BEFORE_MARK_START, WB.G1_BEFORE_CLEANUP_COMPLETED, ExpectedState.NOTMARKED_CANDIDATE_NOTRECLAIMED); 191 192 System.out.println("Tests checking eager reclaim for when the object is allocated after mark start."); 193 // These must not be marked (as they were allocated after mark start), and they are always candidates. Reclamation depends on whether there is a reference. 194 runTest(ObjectType.TYPE_ARRAY, ReferencePolicy.DROP, AllocationTiming.AFTER_MARK_START, WB.BEFORE_MARKING_COMPLETED, ExpectedState.NOTMARKED_CANDIDATE_RECLAIMED); 195 runTest(ObjectType.TYPE_ARRAY, ReferencePolicy.DROP, AllocationTiming.AFTER_MARK_START, WB.G1_BEFORE_REBUILD_COMPLETED, ExpectedState.NOTMARKED_CANDIDATE_RECLAIMED); 196 runTest(ObjectType.TYPE_ARRAY, ReferencePolicy.DROP, AllocationTiming.AFTER_MARK_START, WB.G1_BEFORE_CLEANUP_COMPLETED, ExpectedState.NOTMARKED_CANDIDATE_RECLAIMED); 197 198 runTest(ObjectType.TYPE_ARRAY, ReferencePolicy.KEEP, AllocationTiming.AFTER_MARK_START, WB.BEFORE_MARKING_COMPLETED, ExpectedState.NOTMARKED_CANDIDATE_NOTRECLAIMED); 199 runTest(ObjectType.TYPE_ARRAY, ReferencePolicy.KEEP, AllocationTiming.AFTER_MARK_START, WB.G1_BEFORE_REBUILD_COMPLETED, ExpectedState.NOTMARKED_CANDIDATE_NOTRECLAIMED); 200 runTest(ObjectType.TYPE_ARRAY, ReferencePolicy.KEEP, AllocationTiming.AFTER_MARK_START, WB.G1_BEFORE_CLEANUP_COMPLETED, ExpectedState.NOTMARKED_CANDIDATE_NOTRECLAIMED); 201 202 runTest(ObjectType.OBJ_ARRAY, ReferencePolicy.DROP, AllocationTiming.AFTER_MARK_START, WB.BEFORE_MARKING_COMPLETED, ExpectedState.NOTMARKED_CANDIDATE_RECLAIMED); 203 runTest(ObjectType.OBJ_ARRAY, ReferencePolicy.DROP, AllocationTiming.AFTER_MARK_START, WB.G1_BEFORE_REBUILD_COMPLETED, ExpectedState.NOTMARKED_CANDIDATE_RECLAIMED); 204 runTest(ObjectType.OBJ_ARRAY, ReferencePolicy.DROP, AllocationTiming.AFTER_MARK_START, WB.G1_BEFORE_CLEANUP_COMPLETED, ExpectedState.NOTMARKED_CANDIDATE_RECLAIMED); 205 206 runTest(ObjectType.OBJ_ARRAY, ReferencePolicy.KEEP, AllocationTiming.AFTER_MARK_START, WB.BEFORE_MARKING_COMPLETED, ExpectedState.NOTMARKED_CANDIDATE_NOTRECLAIMED); 207 runTest(ObjectType.OBJ_ARRAY, ReferencePolicy.KEEP, AllocationTiming.AFTER_MARK_START, WB.G1_BEFORE_REBUILD_COMPLETED, ExpectedState.NOTMARKED_CANDIDATE_NOTRECLAIMED); 208 runTest(ObjectType.OBJ_ARRAY, ReferencePolicy.KEEP, AllocationTiming.AFTER_MARK_START, WB.G1_BEFORE_CLEANUP_COMPLETED, ExpectedState.NOTMARKED_CANDIDATE_NOTRECLAIMED); 209 } 210 } 211 212 class TestEagerReclaimHumongousRegionsClearMarkBitsRunner { 213 private static final WhiteBox WB = WhiteBox.getWhiteBox(); 214 private static final int SIZE = 1024 * 1024; 215 216 private static Object allocateHumongousObj(boolean useTypeArray) { 217 if (useTypeArray) { 218 return new int[SIZE]; 219 } else { 220 return new Object[SIZE]; 221 } 222 } 223 224 public static void main(String[] args) throws Exception { 225 if (args.length != 4) { 226 throw new Exception("Invalid number of arguments " + args.length); 227 } 228 boolean useTypeArray = Boolean.parseBoolean(args[0]); 229 boolean keepReference = Boolean.parseBoolean(args[1]); 230 boolean allocateAfter = Boolean.parseBoolean(args[2]); 231 String phase = args[3]; 232 233 System.out.println("useTypeArray: " + useTypeArray + " keepReference: " + keepReference + " allocateAfter " + allocateAfter + " phase: " + phase); 234 WB.fullGC(); 235 236 Object largeObj = null; // Allocated humongous object. 237 if (!allocateAfter) { 238 largeObj = allocateHumongousObj(useTypeArray); 239 } 240 241 WB.concurrentGCAcquireControl(); 242 WB.concurrentGCRunTo(phase); 243 244 System.out.println("Phase " + phase + " reached"); 245 246 if (allocateAfter) { 247 largeObj = allocateHumongousObj(useTypeArray); 248 } 249 250 if (!keepReference) { 251 largeObj = null; 252 } 253 WB.youngGC(); // May reclaim the humongous object. 254 255 WB.concurrentGCRunToIdle(); 256 257 System.out.println("Large object at " + largeObj); // Keepalive. 258 } 259 } --- EOF ---