1 /* 2 * Copyright (c) 2018, 2020, 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.stress; 25 26 /* 27 * @test TestReclaimStringsLeaksMemory 28 * @bug 8180048 29 * @summary Ensure that during a Full GC interned string memory is reclaimed completely. 30 * @requires vm.gc=="null" & !vm.graal.enabled & !vm.debug 31 * @library /test/lib 32 * @modules java.base/jdk.internal.misc 33 * @run driver gc.stress.TestReclaimStringsLeaksMemory 34 * @run driver gc.stress.TestReclaimStringsLeaksMemory -XX:+UseSerialGC 35 * @run driver gc.stress.TestReclaimStringsLeaksMemory -XX:+UseParallelGC 36 * @run driver gc.stress.TestReclaimStringsLeaksMemory -XX:+UseG1GC 37 */ 38 39 import java.util.Arrays; 40 import java.util.ArrayList; 41 import java.util.regex.Pattern; 42 import java.util.regex.Matcher; 43 44 import jdk.test.lib.Asserts; 45 import jdk.test.lib.process.OutputAnalyzer; 46 import jdk.test.lib.process.ProcessTools; 47 48 public class TestReclaimStringsLeaksMemory { 49 50 // The amount of memory in kB reserved in the "Symbol" category that indicates a memory leak for 51 // this test. 52 public static final int ReservedThreshold = 70000; 53 54 public static void main(String[] args) throws Exception { 55 ArrayList<String> baseargs = new ArrayList<>(Arrays.asList("-Xms256M", 56 "-Xmx256M", 57 "-Xlog:gc*,stringtable*=debug:gc.log", 58 "-XX:NativeMemoryTracking=summary", 59 "-XX:+UnlockDiagnosticVMOptions", 60 "-XX:+PrintNMTStatistics" )); 61 baseargs.addAll(Arrays.asList(args)); 62 baseargs.add(GCTest.class.getName()); 63 ProcessBuilder pb = ProcessTools.createJavaProcessBuilder(baseargs); 64 verifySymbolMemoryUsageNotTooHigh(new OutputAnalyzer(pb.start())); 65 } 66 67 private static void verifySymbolMemoryUsageNotTooHigh(OutputAnalyzer output) throws Exception { 68 String stdout = output.getStdout(); 69 System.out.println(stdout); 70 71 Pattern p = Pattern.compile("Symbol \\(reserved=(\\d*)"); 72 Matcher m = p.matcher(stdout); 73 74 if (!m.find()) { 75 throw new RuntimeException("Could not find Symbol memory usage in NMT output"); 76 } 77 78 int reserved = Integer.parseInt(m.group(1)); 79 Asserts.assertLT(reserved, ReservedThreshold, "Reserved memory size is " + reserved + "KB which is greater than or equal to " + ReservedThreshold + "KB indicating a memory leak"); 80 81 output.shouldHaveExitValue(0); 82 } 83 84 static class GCTest { 85 public static final String BaseName = "SomeRandomBaseString"; 86 public static volatile String lastString; 87 88 public static void main(String [] args) { 89 for (int iterations = 0; iterations < 20;) { 90 for (int i = 0; i < 1000000; i++) { 91 lastString = (BaseName + i).intern(); 92 } 93 if (++iterations % 5 == 0) { 94 System.gc(); 95 } 96 } 97 // Do one last GC and sleep to give ServiceThread a chance to run. 98 System.out.println("One last gc"); 99 System.gc(); 100 for (int i = 0; i < 100; i++) { 101 try { 102 Thread.sleep(10); 103 } catch (InterruptedException ex) { 104 } 105 } 106 System.out.println("End of test"); 107 } 108 } 109 } 110