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.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 package org.openjdk.bench.java.util.stream.tasks.DictionaryWordValue;
  26 
  27 import org.openjdk.jmh.annotations.Benchmark;
  28 import org.openjdk.jmh.annotations.BenchmarkMode;
  29 import org.openjdk.jmh.annotations.Level;
  30 import org.openjdk.jmh.annotations.Mode;
  31 import org.openjdk.jmh.annotations.OutputTimeUnit;
  32 import org.openjdk.jmh.annotations.Scope;
  33 import org.openjdk.jmh.annotations.Setup;
  34 import org.openjdk.jmh.annotations.State;
  35 
  36 import java.util.Arrays;
  37 import java.util.concurrent.RecursiveTask;
  38 import java.util.concurrent.TimeUnit;
  39 import java.util.function.BinaryOperator;
  40 import java.util.function.Function;
  41 
  42 
  43 /**
  44  * Bulk scenario: searching max "wordValue" through the dictionary (array of strings).
  45  */
  46 @BenchmarkMode(Mode.Throughput)
  47 @OutputTimeUnit(TimeUnit.SECONDS)
  48 @State(Scope.Benchmark)
  49 public class Bulk {
  50 
  51     @Setup(Level.Trial)
  52     public void loadData() {
  53         // cause classload and problem initialization
  54         DictionaryProblem.class.getName();
  55     }
  56 
  57     @Benchmark
  58     public int hm_seq() {
  59         int max = 0;
  60         for (String s : DictionaryProblem.get()) {
  61             int v = DictionaryProblem.wordValue(s);
  62             if (v > max) {
  63                 max = v;
  64             }
  65         }
  66         return max;
  67     }
  68 
  69     @Benchmark
  70     public int hm_par() {
  71         return new Task(DictionaryProblem.get(), 0, DictionaryProblem.get().length).invoke();
  72     }
  73 
  74     @Benchmark
  75     public int bulk_seq_inner() {
  76         return Arrays.stream(DictionaryProblem.get())
  77                 .map(new Function<String, Integer>() {
  78                     @Override
  79                     public Integer apply(String s) {
  80                         return DictionaryProblem.wordValue(s);
  81                     }
  82                 })
  83                 .reduce(0, new BinaryOperator<Integer>() {
  84                     @Override
  85                     public Integer apply(Integer l, Integer r) {
  86                         return l > r ? l : r;
  87                     }
  88                 });
  89     }
  90 
  91     @Benchmark
  92     public int bulk_par_inner() {
  93         return Arrays.stream(DictionaryProblem.get()).parallel()
  94                 .map(new Function<String, Integer>() {
  95                     @Override
  96                     public Integer apply(String s) {
  97                         return DictionaryProblem.wordValue(s);
  98                     }
  99                 })
 100                 .reduce(0, new BinaryOperator<Integer>() {
 101                     @Override
 102                     public Integer apply(Integer l, Integer r) {
 103                         return l > r ? l : r;
 104                     }
 105                 });
 106     }
 107 
 108 
 109     public static class Task extends RecursiveTask<Integer> {
 110         private static final int FORK_LIMIT = 500;
 111 
 112         private final String[] words;
 113         private final int start, end;
 114 
 115         Task(String[] w, int start, int end) {
 116             this.words = w;
 117             this.start = start;
 118             this.end = end;
 119         }
 120 
 121         @Override
 122         protected Integer compute() {
 123             int size = end - start;
 124             if (size > FORK_LIMIT) {
 125                 int mid = start + size / 2;
 126                 Task t1 = new Task(words, start, mid);
 127                 Task t2 = new Task(words, mid, end);
 128                 t1.fork();
 129                 Integer v2 = t2.invoke();
 130                 Integer v1 = t1.join();
 131                 return Math.max(v1, v2);
 132             } else {
 133                 int max = 0;
 134                 for (int i = start; i < end; i++) {
 135                     int v = DictionaryProblem.wordValue(words[i]);
 136                     if (v > max) {
 137                         max = v;
 138                     }
 139                 }
 140                 return max;
 141             }
 142         }
 143     }
 144 
 145 
 146 }