1 /*
   2  * Copyright (c) 2015, 2015, 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 micro.benchmarks;
  24 
  25 import java.util.Arrays;
  26 
  27 import org.openjdk.jmh.annotations.Benchmark;
  28 import org.openjdk.jmh.annotations.Level;
  29 import org.openjdk.jmh.annotations.OperationsPerInvocation;
  30 import org.openjdk.jmh.annotations.Scope;
  31 import org.openjdk.jmh.annotations.Setup;
  32 import org.openjdk.jmh.annotations.State;
  33 import org.openjdk.jmh.annotations.TearDown;
  34 
  35 @State(Scope.Thread)
  36 public class ArrayDuplicationBenchmark extends BenchmarkBase {
  37 
  38     /** How large should the test-arrays be. */
  39     private static final int TESTSIZE = 300;
  40 
  41     private Object[][] testObjectArray;
  42 
  43     private Object[] dummy;
  44 
  45     @Setup
  46     public void setup() {
  47         testObjectArray = new Object[TESTSIZE][];
  48         for (int i = 0; i < TESTSIZE; i++) {
  49             testObjectArray[i] = new Object[20];
  50         }
  51     }
  52 
  53     @Setup(Level.Iteration)
  54     public void iterationSetup() {
  55         dummy = new Object[TESTSIZE * 3];
  56     }
  57 
  58     @TearDown(Level.Iteration)
  59     public void iterationTearDown() {
  60         dummy = null;
  61     }
  62 
  63     @Benchmark
  64     @OperationsPerInvocation(TESTSIZE)
  65     public Object[] normalArraycopy() {
  66         int j = 0;
  67         for (int i = 0; i < TESTSIZE; i++) {
  68             dummy[j++] = normalArraycopy(testObjectArray[i]);
  69         }
  70         return dummy;
  71     }
  72 
  73     public Object[] normalArraycopy(Object[] cache) {
  74         Object[] result = new Object[cache.length];
  75         System.arraycopy(cache, 0, result, 0, result.length);
  76         return result;
  77     }
  78 
  79     @Benchmark
  80     @OperationsPerInvocation(TESTSIZE)
  81     public Object[] arraysCopyOf() {
  82         int j = 0;
  83         for (int i = 0; i < TESTSIZE; i++) {
  84             dummy[j++] = arraysCopyOf(testObjectArray[i]);
  85         }
  86         return dummy;
  87     }
  88 
  89     public Object[] arraysCopyOf(Object[] cache) {
  90         return Arrays.copyOf(cache, cache.length);
  91     }
  92 
  93     @Benchmark
  94     @OperationsPerInvocation(TESTSIZE)
  95     public Object[] cloneObjectArray() {
  96         int j = 0;
  97         for (int i = 0; i < TESTSIZE; i++) {
  98             dummy[j++] = arraysClone(testObjectArray[i]);
  99         }
 100         return dummy;
 101     }
 102 
 103     @SuppressWarnings("cast")
 104     public Object[] arraysClone(Object[] cache) {
 105         return (Object[]) cache.clone();
 106     }
 107 
 108 }