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 runtime argument conversion performance for MethodHandles.
  40  * This particular test checks the return type conversion: void -> Integer.
  41  */
  42 @BenchmarkMode(Mode.AverageTime)
  43 @OutputTimeUnit(TimeUnit.NANOSECONDS)
  44 @State(Scope.Thread)
  45 public class MethodHandleConvertReturnReference {
  46 
  47     /*
  48      * Implementation notes:
  49      *
  50      * Baseline is invokeExact call, which presumably measures the performance without argument conversion.
  51      *
  52      * The test is subdivided into three subtests, gradually doing more work:
  53      *   - 1_Convert: calls MH.asType to do actual conversion
  54      *   - 2_MTConvert: instantiates MT, and then calls MH.asType to do actual conversion
  55      *   - 3_Call: calls MH.invoke, requesting argument conversion
  56      *
  57      * Calling virtual method to guarantee side-effects on value, without trading off scalability.
  58      * This test should be executed in non-shared mode.
  59      */
  60 
  61     public int value;
  62 
  63     private MethodHandle mh;
  64     private MethodType newType;
  65 
  66     @Setup
  67     public void setup() throws Throwable {
  68         mh = MethodHandles.lookup().findVirtual(MethodHandleConvertReturnReference.class, "target", MethodType.methodType(void.class));
  69         newType = MethodType.methodType(Integer.class, MethodHandleConvertReturnReference.class);
  70     }
  71 
  72     @Benchmark
  73     public void baselineExact() throws Throwable {
  74         mh.invokeExact(this);
  75     }
  76 
  77     @Benchmark
  78     public MethodHandle test_1_Convert() throws Throwable {
  79         return mh.asType(newType);
  80     }
  81 
  82     @Benchmark
  83     public MethodHandle test_2_MTConvert() throws Throwable {
  84         return mh.asType(MethodType.methodType(Integer.class, MethodHandleConvertReturnReference.class));
  85     }
  86 
  87     @Benchmark
  88     public Object test_3_Call() throws Throwable {
  89         return mh.invoke(this);
  90     }
  91 
  92     public void target() {
  93         value++;
  94     }
  95 
  96 }