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.lang.invoke;
  26 
  27 import org.openjdk.jmh.annotations.Benchmark;
  28 import org.openjdk.jmh.annotations.BenchmarkMode;
  29 import org.openjdk.jmh.annotations.Mode;
  30 import org.openjdk.jmh.annotations.OutputTimeUnit;
  31 import org.openjdk.jmh.annotations.Scope;
  32 import org.openjdk.jmh.annotations.Setup;
  33 import org.openjdk.jmh.annotations.State;
  34 
  35 import java.lang.invoke.MethodHandle;
  36 import java.lang.invoke.MethodHandles;
  37 import java.lang.invoke.MethodType;
  38 import java.util.concurrent.TimeUnit;
  39 
  40 /**
  41  * Benchmark assesses MethodHandles.dropArguments() performance
  42  */
  43 @BenchmarkMode(Mode.AverageTime)
  44 @OutputTimeUnit(TimeUnit.NANOSECONDS)
  45 @State(Scope.Benchmark)
  46 public class MethodHandlesDropArguments {
  47 
  48     /**
  49      * Implementation notes:
  50      *   - calling static method to have consistent arg list without receiver type
  51      *   - using volatile ints as arguments to prevent opportunistic optimizations
  52      *   - using Integers to limit argument conversion costs
  53      */
  54 
  55     private MethodHandle orig;
  56     private MethodHandle modified;
  57 
  58     private volatile Integer arg1 = 42;
  59     private volatile Integer arg2 = 43;
  60     private volatile Integer arg3 = 44;
  61 
  62     @Setup
  63     public void setup() throws Throwable {
  64         orig = MethodHandles.lookup().findStatic(MethodHandlesDropArguments.class, "doWork", MethodType.methodType(int.class, Integer.class, Integer.class, Integer.class));
  65         modified = MethodHandles.dropArguments(orig, 0, int.class);
  66     }
  67 
  68     @Benchmark
  69     public int baselineRaw() throws Throwable {
  70         return doWork(arg1, arg2, arg3);
  71     }
  72 
  73     @Benchmark
  74     public int baselineMH() throws Throwable {
  75         return (int) orig.invokeExact(arg1, arg2, arg3);
  76     }
  77 
  78     @Benchmark
  79     public int testInvoke() throws Throwable {
  80         return (int) modified.invokeExact(0, arg1, arg2, arg3);
  81     }
  82 
  83     @Benchmark
  84     public MethodHandle interCreate() throws Throwable {
  85         return MethodHandles.dropArguments(orig, 0, int.class);
  86     }
  87 
  88     public static int doWork(Integer a, Integer b, Integer c) {
  89         return 31*(31*(31*a + b) + c);
  90     }
  91 
  92 }