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.util.stream.pipeline;
  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.Param;
  30 import org.openjdk.jmh.annotations.Scope;
  31 import org.openjdk.jmh.annotations.Setup;
  32 import org.openjdk.jmh.annotations.State;
  33 
  34 import java.util.Iterator;
  35 import java.util.concurrent.TimeUnit;
  36 import java.util.concurrent.atomic.LongAdder;
  37 import java.util.function.LongConsumer;
  38 import java.util.stream.LongStream;
  39 
  40 /**
  41  * Benchmark for forEach()/iterator()/into() operations;
  42  * Testing which one is faster for semantically-equvalent operations.
  43  */
  44 @BenchmarkMode(Mode.Throughput)
  45 @OutputTimeUnit(TimeUnit.SECONDS)
  46 @State(Scope.Thread)
  47 public class Terminal {
  48 
  49     /**
  50      * Implementation notes:
  51      *   - parallel version requires thread-safe sink, we use the same for sequential version for better comparison
  52      *   - operations are explicit inner classes to untangle unwanted lambda effects
  53      */
  54 
  55     @Param("100000")
  56     private int size;
  57 
  58     private LongAdder sink;
  59     private LongConsumer block;
  60 
  61     @Setup
  62     public void setup() {
  63         sink = new LongAdder();
  64         block = new LongConsumer() {
  65             @Override
  66             public void accept(long v) {
  67                 sink.add(v);
  68             }
  69         };
  70     }
  71 
  72     @Benchmark
  73     public long baseline_prim_acc() {
  74         long s = 0;
  75         for (long l = 0L; l < size; l++) {
  76             s += l;
  77         }
  78         sink.add(s);
  79         return sink.sum();
  80     }
  81 
  82     @Benchmark
  83     public long baseline_prim_sink() {
  84         for (long l = 0L; l < size; l++) {
  85             sink.add(l);
  86         }
  87         return sink.sum();
  88     }
  89 
  90     @Benchmark
  91     public long baseline_iterator_acc() {
  92         long s = 0;
  93         for (Iterator<Long> iterator = LongStream.range(0, size).boxed().iterator(); iterator.hasNext(); ) {
  94             Long l = iterator.next();
  95             s += l;
  96         }
  97         sink.add(s);
  98         return sink.sum();
  99     }
 100 
 101     @Benchmark
 102     public long baseline_iterator_sink() {
 103         for (Iterator<Long> iterator = LongStream.range(0, size).boxed().iterator(); iterator.hasNext(); ) {
 104             sink.add(iterator.next());
 105         }
 106         return sink.sum();
 107     }
 108 
 109     @Benchmark
 110     public long seq_iterator() {
 111         Iterator<Long> i = LongStream.range(0, size).boxed().iterator();
 112         while (i.hasNext()) {
 113             sink.add(i.next());
 114         }
 115         return sink.sum();
 116     }
 117 
 118     @Benchmark
 119     public long par_iterator() {
 120         Iterator<Long> i = LongStream.range(0, size).parallel().boxed().iterator();
 121         while (i.hasNext()) {
 122             sink.add(i.next());
 123         }
 124         return sink.sum();
 125     }
 126 
 127     @Benchmark
 128     public long seq_forEach() {
 129         LongStream.range(1, size).forEach(block);
 130         return sink.sum();
 131     }
 132 
 133     @Benchmark
 134     public long par_forEach() {
 135         LongStream.range(1, size).parallel().forEach(block);
 136         return sink.sum();
 137     }
 138 
 139     @Benchmark
 140     public long seq_into() {
 141         return LongStream.range(1, size)
 142                 .collect(LongAdder::new, LongAdder::add, (la1, la2) -> la1.add(la2.sum())).sum();
 143     }
 144 
 145     @Benchmark
 146     public long par_into() {
 147         return LongStream.range(1, size).parallel()
 148                 .collect(LongAdder::new, LongAdder::add, (la1, la2) -> la1.add(la2.sum())).sum();
 149     }
 150 
 151 }