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.vm.lang;
  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.OperationsPerInvocation;
  31 import org.openjdk.jmh.annotations.OutputTimeUnit;
  32 import org.openjdk.jmh.annotations.Scope;
  33 import org.openjdk.jmh.annotations.Setup;
  34 import org.openjdk.jmh.annotations.State;
  35 
  36 import java.io.Serializable;
  37 import java.util.Date;
  38 import java.util.concurrent.TimeUnit;
  39 
  40 /**
  41  * Tests various usages of instanceof.
  42  */
  43 @BenchmarkMode(Mode.AverageTime)
  44 @OutputTimeUnit(TimeUnit.NANOSECONDS)
  45 @State(Scope.Thread)
  46 public class InstanceOf {
  47 
  48     private static final int NOOFOBJECTS = 100;
  49     private static final int NULLRATIO = 3;
  50 
  51     public Date[] dateArray;
  52     public Object[] objectArray;
  53 
  54     @Setup
  55     public void setup() {
  56         dateArray = new Date[NOOFOBJECTS * NULLRATIO];
  57         for (int i = 0; i < NOOFOBJECTS * NULLRATIO; i += NULLRATIO) {
  58             dateArray[i] = new Date();
  59         }
  60         objectArray = dateArray;
  61     }
  62 
  63     /**
  64      * Performs "instanceof Cloneable" on objects that definitely are of that interface. It is not clear however whether
  65      * the objects are null or not, therefore a simple nullcheck is all that should be left of here.
  66      */
  67     @Benchmark
  68     @OperationsPerInvocation((NOOFOBJECTS * NULLRATIO))
  69     public int instanceOfInterfacePartialRemove() {
  70         int dummy = 0;
  71         Date[] localArray = dateArray;
  72         for (int i = 0; i < NOOFOBJECTS * NULLRATIO; i++) {
  73             if (localArray[i] instanceof Cloneable) {
  74                 dummy++;
  75             }
  76         }
  77         return dummy;
  78     }
  79 
  80     /**
  81      * Performs three serial instanceof statements on the same object for three different interfaces. The objects are
  82      * 50% null, and all non-null are instanceof the last interface.
  83      */
  84     @Benchmark
  85     @OperationsPerInvocation((NOOFOBJECTS * NULLRATIO))
  86     public int instanceOfInterfaceSerial() {
  87         int dummy = 0;
  88         Object[] localArray = objectArray;
  89         for (int i = 0; i < NOOFOBJECTS * NULLRATIO; i++) {
  90             if (localArray[i] instanceof Runnable) {
  91                 dummy += 1000;
  92             } else if (localArray[i] instanceof CharSequence) {
  93                 dummy += 2000;
  94             } else if (localArray[i] instanceof Serializable) {
  95                 dummy++;
  96             }
  97         }
  98         return dummy;
  99     }
 100 }