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.gc;
  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.OutputTimeUnit;
  31 import org.openjdk.jmh.annotations.Scope;
  32 import org.openjdk.jmh.annotations.State;
  33 import org.openjdk.jmh.infra.Blackhole;
  34 
  35 import java.util.concurrent.TimeUnit;
  36 
  37 @BenchmarkMode(Mode.AverageTime)
  38 @OutputTimeUnit(TimeUnit.NANOSECONDS)
  39 @State(Scope.Thread)
  40 public class Alloc {
  41 
  42     public static final int LENGTH = 400;
  43     public static final int ARR_LEN = 100;
  44     public int largeLen = 100;
  45     public int smalllen = 6;
  46 
  47     @Benchmark
  48     public void testLargeConstArray(Blackhole bh) throws Exception {
  49         int localArrlen = ARR_LEN;
  50         for (int i = 0; i < LENGTH; i++) {
  51             Object[] tmp = new Object[localArrlen];
  52             bh.consume(tmp);
  53         }
  54     }
  55 
  56     @Benchmark
  57     public void testLargeVariableArray(Blackhole bh) throws Exception {
  58         int localArrlen = largeLen;
  59         for (int i = 0; i < LENGTH; i++) {
  60             Object[] tmp = new Object[localArrlen];
  61             bh.consume(tmp);
  62         }
  63     }
  64 
  65     @Benchmark
  66     public void testSmallConstArray(Blackhole bh) throws Exception {
  67         int localArrlen = largeLen;
  68         for (int i = 0; i < LENGTH; i++) {
  69             Object[] tmp = new Object[localArrlen];
  70             bh.consume(tmp);
  71         }
  72     }
  73 
  74     @Benchmark
  75     public void testSmallObject(Blackhole bh) throws Exception {
  76         FortyBytes localDummy = null;
  77         for (int i = 0; i < LENGTH; i++) {
  78             FortyBytes tmp = new FortyBytes();
  79             tmp.next = localDummy;
  80             localDummy = tmp;
  81             bh.consume(tmp);
  82         }
  83     }
  84 
  85     @Benchmark
  86     public void testSmallVariableArray(Blackhole bh) throws Exception {
  87         int localArrlen = smalllen;
  88         for (int i = 0; i < LENGTH; i++) {
  89             Object[] tmp = new Object[localArrlen];
  90             bh.consume(tmp);
  91         }
  92     }
  93 
  94     final class FortyBytes {
  95         Object next;
  96         int y, z, k, f, g, e, t;
  97     }
  98 
  99 }