1 /*
   2  * Copyright (c) 2017, 2018, Red Hat, Inc. 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 
  25 /*
  26  * @test TestStringDedup
  27  * @summary Test Shenandoah string deduplication implementation
  28  * @key randomness
  29  * @requires vm.gc.Shenandoah & !vm.graal.enabled
  30  * @library /test/lib
  31  * @modules java.base/jdk.internal.misc:open
  32  * @modules java.base/java.lang:open
  33  *          java.management
  34  *
  35  * @run main/othervm -Xmx256m -Xlog:gc+stats -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
  36  *      -XX:+UseShenandoahGC -XX:ShenandoahGCMode=passive
  37  *      -XX:+ShenandoahDegeneratedGC
  38  *      TestStringDedup
  39  *
  40  * @run main/othervm -Xmx256m -Xlog:gc+stats -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
  41  *      -XX:+UseShenandoahGC -XX:ShenandoahGCMode=passive
  42  *      -XX:-ShenandoahDegeneratedGC
  43  *      TestStringDedup
  44  */
  45 
  46 /*
  47  * @test TestStringDedup
  48  * @summary Test Shenandoah string deduplication implementation
  49  * @key randomness
  50  * @requires vm.gc.Shenandoah & !vm.graal.enabled
  51  * @library /test/lib
  52  * @modules java.base/jdk.internal.misc:open
  53  * @modules java.base/java.lang:open
  54  *          java.management
  55  *
  56  * @run main/othervm -Xmx256m -Xlog:gc+stats -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
  57  *      -XX:+UseShenandoahGC -XX:ShenandoahGCHeuristics=aggressive
  58  *      TestStringDedup
  59  *
  60  * @run main/othervm -Xmx256m -Xlog:gc+stats -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
  61  *      -XX:+UseShenandoahGC
  62  *      TestStringDedup
  63  *
  64  * @run main/othervm -Xmx256m -Xlog:gc+stats -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
  65  *      -XX:+UseShenandoahGC -XX:ShenandoahGCHeuristics=compact
  66  *      TestStringDedup
  67  */
  68 
  69 /*
  70  * @test TestStringDedup
  71  * @summary Test Shenandoah string deduplication implementation
  72  * @key randomness
  73  * @requires vm.gc.Shenandoah & !vm.graal.enabled
  74  * @library /test/lib
  75  * @modules java.base/jdk.internal.misc:open
  76  * @modules java.base/java.lang:open
  77  *          java.management
  78  *
  79  * @run main/othervm -Xmx256m -Xlog:gc+stats -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
  80  *      -XX:+UseShenandoahGC -XX:ShenandoahGCMode=iu
  81  *      TestStringDedup
  82  *
  83  * @run main/othervm -Xmx256m -Xlog:gc+stats -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
  84  *      -XX:+UseShenandoahGC -XX:ShenandoahGCMode=iu -XX:ShenandoahGCHeuristics=aggressive
  85  *      TestStringDedup
  86  */
  87 
  88 import java.lang.reflect.*;
  89 import java.util.*;
  90 import jdk.test.lib.Utils;
  91 
  92 import sun.misc.*;
  93 
  94 public class TestStringDedup {
  95     private static Field valueField;
  96     private static Unsafe unsafe;
  97 
  98     private static final int UniqueStrings = 20;
  99 
 100     static {
 101         try {
 102             Field field = Unsafe.class.getDeclaredField("theUnsafe");
 103             field.setAccessible(true);
 104             unsafe = (Unsafe) field.get(null);
 105 
 106             valueField = String.class.getDeclaredField("value");
 107             valueField.setAccessible(true);
 108         } catch (Exception e) {
 109             throw new RuntimeException(e);
 110         }
 111     }
 112 
 113     private static Object getValue(String string) {
 114         try {
 115             return valueField.get(string);
 116         } catch (Exception e) {
 117             throw new RuntimeException(e);
 118         }
 119     }
 120 
 121     static class StringAndId {
 122         private String str;
 123         private int id;
 124 
 125         public StringAndId(String str, int id) {
 126             this.str = str;
 127             this.id = id;
 128         }
 129 
 130         public String str() {
 131             return str;
 132         }
 133 
 134         public int id() {
 135             return id;
 136         }
 137     }
 138 
 139     private static void generateStrings(ArrayList<StringAndId> strs, int unique_strs) {
 140         Random rn = Utils.getRandomInstance();
 141         for (int u = 0; u < unique_strs; u++) {
 142             int n = rn.nextInt() % 10;
 143             n = Math.max(n, 2);
 144             for (int index = 0; index < n; index++) {
 145                 strs.add(new StringAndId("Unique String " + u, u));
 146             }
 147         }
 148     }
 149 
 150     private static int verifyDedepString(ArrayList<StringAndId> strs) {
 151         HashMap<Object, StringAndId> seen = new HashMap<>();
 152         int total = 0;
 153         int dedup = 0;
 154 
 155         for (StringAndId item : strs) {
 156             total++;
 157             StringAndId existing_item = seen.get(getValue(item.str()));
 158             if (existing_item == null) {
 159                 seen.put(getValue(item.str()), item);
 160             } else {
 161                 if (item.id() != existing_item.id() ||
 162                         !item.str().equals(existing_item.str())) {
 163                     System.out.println("StringDedup error:");
 164                     System.out.println("String: " + item.str() + " != " + existing_item.str());
 165                     throw new RuntimeException("StringDedup Test failed");
 166                 } else {
 167                     dedup++;
 168                 }
 169             }
 170         }
 171         System.out.println("Dedup: " + dedup + "/" + total + " unique: " + (total - dedup));
 172         return (total - dedup);
 173     }
 174 
 175     public static void main(String[] args) {
 176         ArrayList<StringAndId> astrs = new ArrayList<>();
 177         generateStrings(astrs, UniqueStrings);
 178         System.gc();
 179         System.gc();
 180         System.gc();
 181         System.gc();
 182         System.gc();
 183 
 184         if (verifyDedepString(astrs) != UniqueStrings) {
 185             // Can not guarantee all strings are deduplicated, there can
 186             // still have pending items in queues.
 187             System.out.println("Not all strings are deduplicated");
 188         }
 189     }
 190 }