1 /* 2 * Copyright (c) 2014, 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 package org.openjdk.bench.java.lang; 24 25 import org.openjdk.jmh.annotations.Benchmark; 26 import org.openjdk.jmh.annotations.BenchmarkMode; 27 import org.openjdk.jmh.annotations.Mode; 28 import org.openjdk.jmh.annotations.OutputTimeUnit; 29 import org.openjdk.jmh.annotations.Scope; 30 import org.openjdk.jmh.annotations.Setup; 31 import org.openjdk.jmh.annotations.State; 32 import org.openjdk.jmh.infra.Blackhole; 33 34 import java.util.Random; 35 import java.util.concurrent.TimeUnit; 36 37 @BenchmarkMode(Mode.AverageTime) 38 @OutputTimeUnit(TimeUnit.NANOSECONDS) 39 @State(Scope.Thread) 40 public class StringOther { 41 42 private String testString; 43 private Random rnd; 44 45 private String str1, str2, str3, str4; 46 47 @Setup 48 public void setup() { 49 testString = "Idealism is what precedes experience; cynicism is what follows."; 50 str1 = "vm-guld vm-guld vm-guld"; 51 str2 = "vm-guld vm-guld vm-guldx"; 52 str3 = "vm-guld vm-guld vm-guldx"; 53 str4 = "adadaskasdjierudks"; 54 rnd = new Random(); 55 } 56 57 @Benchmark 58 public void charAt(Blackhole bh) { 59 for (int i = 0; i < testString.length(); i++) { 60 bh.consume(testString.charAt(i)); 61 } 62 } 63 64 @Benchmark 65 public int compareTo() { 66 int total = 0; 67 total += str1.compareTo(str2); 68 total += str2.compareTo(str3); 69 total += str3.compareTo(str4); 70 return total; 71 } 72 73 /** 74 * Creates (hopefully) unique Strings and internizes them, creating a zillion forgettable strings in the JVMs string 75 * pool. 76 * <p/> 77 * This will test 1.) The data structure/whatever for getting and adding Strings to intern table. 2.) The 78 * intern-caches (java) behaviour on negative lookup (the string is new) 3.) GC's handling of weak handles. Since 79 * every gc we must process and pretty much kill a zillion interned strings that are now not referenced anymore, the 80 * majority of GC time will be spent in handle processing. So we get a picture of how well the pathological case of 81 * this goes. 82 */ 83 @Benchmark 84 public String internUnique() { 85 return String.valueOf(rnd.nextInt()).intern(); 86 } 87 88 }