1 /*
   2  * Copyright (c) 2017, 2018, Red Hat, Inc. All rights reserved.
   3  *
   4  * This code is free software; you can redistribute it and/or modify it
   5  * under the terms of the GNU General Public License version 2 only, as
   6  * published by the Free Software Foundation.
   7  *
   8  * This code is distributed in the hope that it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  11  * version 2 for more details (a copy is included in the LICENSE file that
  12  * accompanied this code).
  13  *
  14  * You should have received a copy of the GNU General Public License version
  15  * 2 along with this work; if not, write to the Free Software Foundation,
  16  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  17  *
  18  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  19  * or visit www.oracle.com if you need additional information or have any
  20  * questions.
  21  *
  22  */
  23 
  24 /*
  25  * @test TestStringDedup
  26  * @summary Test Shenandoah string deduplication implementation
  27  * @key gc
  28  * @requires vm.gc.Shenandoah & !vm.graal.enabled
  29  * @library /test/lib
  30  * @modules java.base/jdk.internal.misc:open
  31  * @modules java.base/java.lang:open
  32  *          java.management
  33  *
  34  * @run main/othervm -Xmx256m -Xlog:gc+stats -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
  35  *      -XX:+UseShenandoahGC -XX:ShenandoahGCMode=passive
  36  *      -XX:+ShenandoahDegeneratedGC
  37  *      TestStringDedup
  38  *
  39  * @run main/othervm -Xmx256m -Xlog:gc+stats -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
  40  *      -XX:+UseShenandoahGC -XX:ShenandoahGCMode=passive
  41  *      -XX:-ShenandoahDegeneratedGC
  42  *      TestStringDedup
  43  */
  44 
  45 /*
  46  * @test TestStringDedup
  47  * @summary Test Shenandoah string deduplication implementation
  48  * @key gc
  49  * @requires vm.gc.Shenandoah & !vm.graal.enabled
  50  * @library /test/lib
  51  * @modules java.base/jdk.internal.misc:open
  52  * @modules java.base/java.lang:open
  53  *          java.management
  54  *
  55  * @run main/othervm -Xmx256m -Xlog:gc+stats -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
  56  *      -XX:+UseShenandoahGC -XX:ShenandoahGCHeuristics=aggressive
  57  *      TestStringDedup
  58  *
  59  * @run main/othervm -Xmx256m -Xlog:gc+stats -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
  60  *      -XX:+UseShenandoahGC
  61  *      TestStringDedup
  62  *
  63  * @run main/othervm -Xmx256m -Xlog:gc+stats -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
  64  *      -XX:+UseShenandoahGC -XX:ShenandoahGCHeuristics=compact
  65  *      TestStringDedup
  66  */
  67 
  68 /*
  69  * @test TestStringDedup
  70  * @summary Test Shenandoah string deduplication implementation
  71  * @key gc
  72  * @requires vm.gc.Shenandoah & !vm.graal.enabled
  73  * @library /test/lib
  74  * @modules java.base/jdk.internal.misc:open
  75  * @modules java.base/java.lang:open
  76  *          java.management
  77  *
  78  * @run main/othervm -Xmx256m -Xlog:gc+stats -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
  79  *      -XX:+UseShenandoahGC -XX:ShenandoahGCMode=traversal
  80  *      TestStringDedup
  81  *
  82  * @run main/othervm -Xmx256m -Xlog:gc+stats -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseStringDeduplication
  83  *      -XX:+UseShenandoahGC -XX:ShenandoahGCMode=traversal -XX:ShenandoahGCHeuristics=aggressive
  84  *      TestStringDedup
  85  */
  86 
  87 import java.lang.reflect.*;
  88 import java.util.*;
  89 
  90 import sun.misc.*;
  91 
  92 public class TestStringDedup {
  93     private static Field valueField;
  94     private static Unsafe unsafe;
  95 
  96     private static final int UniqueStrings = 20;
  97 
  98     static {
  99         try {
 100             Field field = Unsafe.class.getDeclaredField("theUnsafe");
 101             field.setAccessible(true);
 102             unsafe = (Unsafe) field.get(null);
 103 
 104             valueField = String.class.getDeclaredField("value");
 105             valueField.setAccessible(true);
 106         } catch (Exception e) {
 107             throw new RuntimeException(e);
 108         }
 109     }
 110 
 111     private static Object getValue(String string) {
 112         try {
 113             return valueField.get(string);
 114         } catch (Exception e) {
 115             throw new RuntimeException(e);
 116         }
 117     }
 118 
 119     static class StringAndId {
 120         private String str;
 121         private int id;
 122 
 123         public StringAndId(String str, int id) {
 124             this.str = str;
 125             this.id = id;
 126         }
 127 
 128         public String str() {
 129             return str;
 130         }
 131 
 132         public int id() {
 133             return id;
 134         }
 135     }
 136 
 137     private static void generateStrings(ArrayList<StringAndId> strs, int unique_strs) {
 138         Random rn = new Random();
 139         for (int u = 0; u < unique_strs; u++) {
 140             int n = rn.nextInt() % 10;
 141             n = Math.max(n, 2);
 142             for (int index = 0; index < n; index++) {
 143                 strs.add(new StringAndId("Unique String " + u, u));
 144             }
 145         }
 146     }
 147 
 148     private static int verifyDedepString(ArrayList<StringAndId> strs) {
 149         HashMap<Object, StringAndId> seen = new HashMap<>();
 150         int total = 0;
 151         int dedup = 0;
 152 
 153         for (StringAndId item : strs) {
 154             total++;
 155             StringAndId existing_item = seen.get(getValue(item.str()));
 156             if (existing_item == null) {
 157                 seen.put(getValue(item.str()), item);
 158             } else {
 159                 if (item.id() != existing_item.id() ||
 160                         !item.str().equals(existing_item.str())) {
 161                     System.out.println("StringDedup error:");
 162                     System.out.println("String: " + item.str() + " != " + existing_item.str());
 163                     throw new RuntimeException("StringDedup Test failed");
 164                 } else {
 165                     dedup++;
 166                 }
 167             }
 168         }
 169         System.out.println("Dedup: " + dedup + "/" + total + " unique: " + (total - dedup));
 170         return (total - dedup);
 171     }
 172 
 173     public static void main(String[] args) {
 174         ArrayList<StringAndId> astrs = new ArrayList<>();
 175         generateStrings(astrs, UniqueStrings);
 176         System.gc();
 177         System.gc();
 178         System.gc();
 179         System.gc();
 180         System.gc();
 181 
 182         if (verifyDedepString(astrs) != UniqueStrings) {
 183             // Can not guarantee all strings are deduplicated, there can
 184             // still have pending items in queues.
 185             System.out.println("Not all strings are deduplicated");
 186         }
 187     }
 188 }