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.vm.lang;
  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.OperationsPerInvocation;
  29 import org.openjdk.jmh.annotations.OutputTimeUnit;
  30 import org.openjdk.jmh.annotations.Scope;
  31 import org.openjdk.jmh.annotations.Setup;
  32 import org.openjdk.jmh.annotations.State;
  33 
  34 import java.io.Serializable;
  35 import java.util.Date;
  36 import java.util.concurrent.TimeUnit;
  37 
  38 /**
  39  * Tests various usages of instanceof.
  40  */
  41 @BenchmarkMode(Mode.AverageTime)
  42 @OutputTimeUnit(TimeUnit.NANOSECONDS)
  43 @State(Scope.Thread)
  44 public class InstanceOf {
  45 
  46     private static final int NOOFOBJECTS = 100;
  47     private static final int NULLRATIO = 3;
  48 
  49     public Date[] dateArray;
  50     public Object[] objectArray;
  51 
  52     @Setup
  53     public void setup() {
  54         dateArray = new Date[NOOFOBJECTS * NULLRATIO];
  55         for (int i = 0; i < NOOFOBJECTS * NULLRATIO; i += NULLRATIO) {
  56             dateArray[i] = new Date();
  57         }
  58         objectArray = dateArray;
  59     }
  60 
  61     /**
  62      * Performs "instanceof Cloneable" on objects that definitely are of that interface. It is not clear however whether
  63      * the objects are null or not, therefore a simple nullcheck is all that should be left of here.
  64      */
  65     @Benchmark
  66     @OperationsPerInvocation((NOOFOBJECTS * NULLRATIO))
  67     public int instanceOfInterfacePartialRemove() {
  68         int dummy = 0;
  69         Date[] localArray = dateArray;
  70         for (int i = 0; i < NOOFOBJECTS * NULLRATIO; i++) {
  71             if (localArray[i] instanceof Cloneable) {
  72                 dummy++;
  73             }
  74         }
  75         return dummy;
  76     }
  77 
  78     /**
  79      * Performs three serial instanceof statements on the same object for three different interfaces. The objects are
  80      * 50% null, and all non-null are instanceof the last interface.
  81      */
  82     @Benchmark
  83     @OperationsPerInvocation((NOOFOBJECTS * NULLRATIO))
  84     public int instanceOfInterfaceSerial() {
  85         int dummy = 0;
  86         Object[] localArray = objectArray;
  87         for (int i = 0; i < NOOFOBJECTS * NULLRATIO; i++) {
  88             if (localArray[i] instanceof Runnable) {
  89                 dummy += 1000;
  90             } else if (localArray[i] instanceof CharSequence) {
  91                 dummy += 2000;
  92             } else if (localArray[i] instanceof Serializable) {
  93                 dummy++;
  94             }
  95         }
  96         return dummy;
  97     }
  98 }