diff -r 4d8a023c2a03 -r 16609197022c test/micro/org/openjdk/bench/java/lang/StringOther.java --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/test/micro/org/openjdk/bench/java/lang/StringOther.java Fri Nov 16 23:39:51 2018 +0100 @@ -0,0 +1,88 @@ +/* + * Copyright (c) 2014 Oracle and/or its affiliates. All rights reserved. + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. + * + * This code is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 only, as + * published by the Free Software Foundation. + * + * This code is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * version 2 for more details (a copy is included in the LICENSE file that + * accompanied this code). + * + * You should have received a copy of the GNU General Public License version + * 2 along with this work; if not, write to the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. + * + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA + * or visit www.oracle.com if you need additional information or have any + * questions. + */ +package org.openjdk.bench.java.lang; + +import org.openjdk.jmh.annotations.Benchmark; +import org.openjdk.jmh.annotations.BenchmarkMode; +import org.openjdk.jmh.annotations.Mode; +import org.openjdk.jmh.annotations.OutputTimeUnit; +import org.openjdk.jmh.annotations.Scope; +import org.openjdk.jmh.annotations.Setup; +import org.openjdk.jmh.annotations.State; +import org.openjdk.jmh.infra.Blackhole; + +import java.util.Random; +import java.util.concurrent.TimeUnit; + +@BenchmarkMode(Mode.AverageTime) +@OutputTimeUnit(TimeUnit.NANOSECONDS) +@State(Scope.Thread) +public class StringOther { + + private String testString; + private Random rnd; + + private String str1, str2, str3, str4; + + @Setup + public void setup() { + testString = "Idealism is what precedes experience; cynicism is what follows."; + str1 = "vm-guld vm-guld vm-guld"; + str2 = "vm-guld vm-guld vm-guldx"; + str3 = "vm-guld vm-guld vm-guldx"; + str4 = "adadaskasdjierudks"; + rnd = new Random(); + } + + @Benchmark + public void charAt(Blackhole bh) { + for (int i = 0; i < testString.length(); i++) { + bh.consume(testString.charAt(i)); + } + } + + @Benchmark + public int compareTo() { + int total = 0; + total += str1.compareTo(str2); + total += str2.compareTo(str3); + total += str3.compareTo(str4); + return total; + } + + /** + * Creates (hopefully) unique Strings and internizes them, creating a zillion forgettable strings in the JVMs string + * pool. + *

+ * This will test 1.) The data structure/whatever for getting and adding Strings to intern table. 2.) The + * intern-caches (java) behaviour on negative lookup (the string is new) 3.) GC's handling of weak handles. Since + * every gc we must process and pretty much kill a zillion interned strings that are now not referenced anymore, the + * majority of GC time will be spent in handle processing. So we get a picture of how well the pathological case of + * this goes. + */ + @Benchmark + public String internUnique() { + return String.valueOf(rnd.nextInt()).intern(); + } + +}