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  * Benchmark assesses MethodHandles.guardWithTest() performance
  40  */
  41 @BenchmarkMode(Mode.AverageTime)
  42 @OutputTimeUnit(TimeUnit.NANOSECONDS)
  43 @State(Scope.Thread)
  44 public class MethodHandlesGuardWithTest {
  45 
  46     /**
  47      * Implementation notes:
  48      *   - using volatile ints as arguments to prevent opportunistic optimizations
  49      *   - using Integers to limit argument conversion costs
  50      *   - tested method should perform no worse than the baseline
  51      */
  52 
  53     private MethodHandle mhWork1;
  54     private MethodHandle mhWork2;
  55     private MethodHandle guard;
  56     private boolean choice;
  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         MethodType mt = MethodType.methodType(int.class, Integer.class, Integer.class, Integer.class);
  65         mhWork1 = MethodHandles.lookup().findVirtual(MethodHandlesGuardWithTest.class, "doWork1", mt);
  66         mhWork2 = MethodHandles.lookup().findVirtual(MethodHandlesGuardWithTest.class, "doWork2", mt);
  67 
  68         MethodHandle chooser = MethodHandles.lookup().findVirtual(MethodHandlesGuardWithTest.class, "chooser", MethodType.methodType(boolean.class));
  69         guard = MethodHandles.guardWithTest(chooser, mhWork1, mhWork2);
  70     }
  71 
  72     @Benchmark
  73     public int baselineManual() throws Throwable {
  74         if (choice) {
  75             return (int) mhWork1.invokeExact(this, arg1, arg2, arg3);
  76         } else {
  77             return (int) mhWork2.invokeExact(this, arg1, arg2, arg3);
  78         }
  79     }
  80 
  81     @Benchmark
  82     public int testInvoke() throws Throwable {
  83         return (int) guard.invoke(this, arg1, arg2, arg3);
  84     }
  85 
  86     public boolean chooser() {
  87         choice = !choice;
  88         return choice;
  89     }
  90 
  91     public int doWork1(Integer a, Integer b, Integer c) {
  92         return 31*(31*(31*a + b) + c);
  93     }
  94 
  95     public int doWork2(Integer a, Integer b, Integer c) {
  96         return 31*(31*(31*c + b) + a);
  97     }
  98 }