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 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:ShenandoahGCHeuristics=passive -XX:+ShenandoahDegeneratedGC -XX:+UseStringDeduplication -Xmx256M -Xlog:gc+stats TestStringDedup 34 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:ShenandoahGCHeuristics=passive -XX:-ShenandoahDegeneratedGC -XX:+UseStringDeduplication -Xmx256M -Xlog:gc+stats TestStringDedup 35 * 36 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:ShenandoahGCHeuristics=aggressive -XX:+UseStringDeduplication -Xmx256M -Xlog:gc+stats TestStringDedup 37 * 38 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:+UseStringDeduplication -Xmx256M -Xlog:gc+stats TestStringDedup 39 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:ShenandoahGCHeuristics=traversal -XX:+UseStringDeduplication -Xmx256M -Xlog:gc+stats TestStringDedup 40 * 41 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:ShenandoahGCHeuristics=compact -XX:+UseStringDeduplication -Xmx256M -Xlog:gc+stats TestStringDedup 42 */ 43 44 import java.lang.reflect.*; 45 import java.util.*; 46 47 import sun.misc.*; 48 49 public class TestStringDedup { 50 private static Field valueField; 51 private static Unsafe unsafe; 52 53 private static final int UniqueStrings = 20; 54 55 static { 56 try { 57 Field field = Unsafe.class.getDeclaredField("theUnsafe"); 58 field.setAccessible(true); 59 unsafe = (Unsafe) field.get(null); 60 61 valueField = String.class.getDeclaredField("value"); 62 valueField.setAccessible(true); 63 } catch (Exception e) { 64 throw new RuntimeException(e); 65 } 66 } 67 68 private static Object getValue(String string) { 69 try { 70 return valueField.get(string); 71 } catch (Exception e) { 72 throw new RuntimeException(e); 73 } 74 } 75 76 static class StringAndId { 77 private String str; 78 private int id; 79 80 public StringAndId(String str, int id) { 81 this.str = str; 82 this.id = id; 83 } 84 85 public String str() { 86 return str; 87 } 88 89 public int id() { 90 return id; 91 } 92 } 93 94 private static void generateStrings(ArrayList<StringAndId> strs, int unique_strs) { 95 Random rn = new Random(); 96 for (int u = 0; u < unique_strs; u++) { 97 int n = rn.nextInt() % 10; 98 n = Math.max(n, 2); 99 for (int index = 0; index < n; index++) { 100 strs.add(new StringAndId("Unique String " + u, u)); 101 } 102 } 103 } 104 105 private static int verifyDedepString(ArrayList<StringAndId> strs) { 106 HashMap<Object, StringAndId> seen = new HashMap<>(); 107 int total = 0; 108 int dedup = 0; 109 110 for (StringAndId item : strs) { 111 total++; 112 StringAndId existing_item = seen.get(getValue(item.str())); 113 if (existing_item == null) { 114 seen.put(getValue(item.str()), item); 115 } else { 116 if (item.id() != existing_item.id() || 117 !item.str().equals(existing_item.str())) { 118 System.out.println("StringDedup error:"); 119 System.out.println("String: " + item.str() + " != " + existing_item.str()); 120 throw new RuntimeException("StringDedup Test failed"); 121 } else { 122 dedup++; 123 } 124 } 125 } 126 System.out.println("Dedup: " + dedup + "/" + total + " unique: " + (total - dedup)); 127 return (total - dedup); 128 } 129 130 public static void main(String[] args) { 131 ArrayList<StringAndId> astrs = new ArrayList<>(); 132 generateStrings(astrs, UniqueStrings); 133 System.gc(); 134 System.gc(); 135 System.gc(); 136 System.gc(); 137 System.gc(); 138 139 if (verifyDedepString(astrs) != UniqueStrings) { 140 // Can not guarantee all strings are deduplicated, there can 141 // still have pending items in queues. 142 System.out.println("Not all strings are deduplicated"); 143 } 144 } 145 }