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.invoke;
  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 
  33 import java.lang.invoke.MethodHandle;
  34 import java.lang.invoke.MethodHandles;
  35 import java.lang.invoke.MethodType;
  36 import java.util.concurrent.TimeUnit;
  37 
  38 /**
  39  * Microbenchmark assesses MethodHandle.asCollector() performance
  40  */
  41 @BenchmarkMode(Mode.AverageTime)
  42 @OutputTimeUnit(TimeUnit.NANOSECONDS)
  43 @State(Scope.Thread)
  44 public class MethodHandleAsCollector {
  45 
  46     /*
  47     * Implementation notes:
  48     *   - simple array-parameter method is being called
  49     *   - baselineRaw calls method directly with dynamically instantiating the array
  50     *   - baselineCached calls method directly with pre-cached array
  51     *   - additional testCreate() test harnesses the collector acquisition performance
  52     *   - testCollector() can be faster than both baselines: it can wrapping array at all
  53     */
  54 
  55     public int i;
  56     private static MethodHandle mh;
  57     private static MethodHandle collectorMH;
  58     private static int[] cachedArgs;
  59 
  60     @Setup
  61     public void setup() throws IllegalAccessException, NoSuchMethodException {
  62         mh = MethodHandles.lookup().findVirtual(MethodHandleAsCollector.class, "doWork", MethodType.methodType(void.class, int[].class));
  63         collectorMH = mh.asCollector(int[].class, 5);
  64         cachedArgs = new int[]{1, 2, 3, 4, 5};
  65     }
  66 
  67     @Benchmark
  68     public void baselineMH() throws Throwable {
  69         mh.invokeExact(this, new int[] { 1, 2, 3, 4, 5 });
  70     }
  71 
  72     @Benchmark
  73     public void baselineMHCached() throws Throwable {
  74         mh.invokeExact(this, cachedArgs);
  75     }
  76 
  77     @Benchmark
  78     public void baselineRaw() throws Throwable {
  79         doWork(new int[] { 1, 2, 3, 4, 5});
  80     }
  81 
  82     @Benchmark
  83     public void baselineRawCached() throws Throwable {
  84         doWork(cachedArgs);
  85     }
  86 
  87     @Benchmark
  88     public MethodHandle testCreate() {
  89         return mh.asCollector(int[].class, 5);
  90     }
  91 
  92     @Benchmark
  93     public void testCollector() throws Throwable {
  94         collectorMH.invokeExact(this, 1, 2, 3, 4, 5);
  95     }
  96 
  97     public void doWork(int[] args) {
  98         for (int a : args) {
  99             i += a;
 100         }
 101     }
 102 
 103 }