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" 31 * @requires !vm.debug 32 * @library /test/lib 33 * @modules java.base/jdk.internal.misc 34 * @run driver gc.stress.TestReclaimStringsLeaksMemory 35 * @run driver gc.stress.TestReclaimStringsLeaksMemory -XX:+UseSerialGC 36 * @run driver gc.stress.TestReclaimStringsLeaksMemory -XX:+UseParallelGC 37 * @run driver gc.stress.TestReclaimStringsLeaksMemory -XX:+UseG1GC 38 */ 39 40 import java.util.Arrays; 41 import java.util.ArrayList; 42 import java.util.regex.Pattern; 43 import java.util.regex.Matcher; 44 45 import jdk.test.lib.Asserts; 46 import jdk.test.lib.process.OutputAnalyzer; 47 import jdk.test.lib.process.ProcessTools; 48 49 public class TestReclaimStringsLeaksMemory { 50 51 // The amount of memory in kB reserved in the "Symbol" category that indicates a memory leak for 52 // this test. 53 public static final int ReservedThreshold = 70000; 54 55 public static void main(String[] args) throws Exception { 56 ArrayList<String> baseargs = new ArrayList<>(Arrays.asList("-Xms256M", 57 "-Xmx256M", 58 "-Xlog:gc*,stringtable*=debug:gc.log", 59 "-XX:NativeMemoryTracking=summary", 60 "-XX:+UnlockDiagnosticVMOptions", 61 "-XX:+PrintNMTStatistics" )); 62 baseargs.addAll(Arrays.asList(args)); 63 baseargs.add(GCTest.class.getName()); 64 ProcessBuilder pb = ProcessTools.createJavaProcessBuilder(baseargs); 65 verifySymbolMemoryUsageNotTooHigh(new OutputAnalyzer(pb.start())); 66 } 67 68 private static void verifySymbolMemoryUsageNotTooHigh(OutputAnalyzer output) throws Exception { 69 String stdout = output.getStdout(); 70 System.out.println(stdout); 71 72 Pattern p = Pattern.compile("Symbol \\(reserved=(\\d*)"); 73 Matcher m = p.matcher(stdout); 74 75 if (!m.find()) { 76 throw new RuntimeException("Could not find Symbol memory usage in NMT output"); 77 } 78 79 int reserved = Integer.parseInt(m.group(1)); 80 Asserts.assertLT(reserved, ReservedThreshold, "Reserved memory size is " + reserved + "KB which is greater than or equal to " + ReservedThreshold + "KB indicating a memory leak"); 81 82 output.shouldHaveExitValue(0); 83 } 84 85 static class GCTest { 86 public static final String BaseName = "SomeRandomBaseString"; 87 public static volatile String lastString; 88 89 public static void main(String [] args) { 90 for (int iterations = 0; iterations < 20;) { 91 for (int i = 0; i < 1000000; i++) { 92 lastString = (BaseName + i).intern(); 93 } 94 if (++iterations % 5 == 0) { 95 System.gc(); 96 } 97 } 98 // Do one last GC and sleep to give ServiceThread a chance to run. 99 System.out.println("One last gc"); 100 System.gc(); 101 for (int i = 0; i < 100; i++) { 102 try { 103 Thread.sleep(10); 104 } catch (InterruptedException ex) { 105 } 106 } 107 System.out.println("End of test"); 108 } 109 } 110 } 111