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.compiler;
  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 
  30 import java.util.concurrent.TimeUnit;
  31 
  32 /**
  33  * Tests how well the JVM can remove stores after allocation of objects.
  34  */
  35 @BenchmarkMode(Mode.AverageTime)
  36 @OutputTimeUnit(TimeUnit.NANOSECONDS)
  37 public class PostAllocationStores {
  38 
  39     /** Tests allocation with explicit stores of null/zero to all fields. */
  40     @Benchmark
  41     public Object testAllocationWithNullStores() throws Exception {
  42         return new TestWithNullStores();
  43     }
  44 
  45     /**
  46      * Tests allocation with explicit stores of non-null/non-zero to all fields. This test exists as a complement to the
  47      * one above.
  48      */
  49     @Benchmark
  50     public Object testAllocationWithNonNullStores() throws Exception {
  51         return new TestWithNonNullStores();
  52     }
  53 
  54     /** Tests allocation with explicit stores of null/zero to all fields, where all fields are volatile. */
  55     @Benchmark
  56     public Object testAllocationWithNullVolatileStores() throws Exception {
  57         return new TestWithNullVolatileStores();
  58     }
  59 
  60     /** Tests allocation without any explicit stores to any fields. */
  61     @Benchmark
  62     public Object testAllocationWithoutStores() throws Exception {
  63         return new TestWithoutStores();
  64     }
  65 
  66     static class TestWithNullStores {
  67         Object objectField1;
  68         Object objectField2;
  69         Object objectField3;
  70         int intField1;
  71         int intField2;
  72         long longField1;
  73 
  74         public TestWithNullStores() {
  75             objectField1 = null;
  76             objectField2 = null;
  77             objectField3 = null;
  78             intField1 = 0;
  79             intField2 = 0;
  80             longField1 = 0L;
  81         }
  82     }
  83 
  84     static class TestWithNonNullStores {
  85         Object objectField1;
  86         Object objectField2;
  87         Object objectField3;
  88         int intField1;
  89         int intField2;
  90         long longField1;
  91 
  92         public TestWithNonNullStores() {
  93             objectField1 = this;
  94             objectField2 = this;
  95             objectField3 = this;
  96             intField1 = 4;
  97             intField2 = 7;
  98             longField1 = 2L;
  99         }
 100     }
 101 
 102     static class TestWithNullVolatileStores {
 103         volatile Object objectField1;
 104         volatile Object objectField2;
 105         volatile Object objectField3;
 106         volatile int intField1;
 107         volatile int intField2;
 108         volatile long longField1;
 109 
 110         public TestWithNullVolatileStores() {
 111             objectField1 = null;
 112             objectField2 = null;
 113             objectField3 = null;
 114             intField1 = 0;
 115             intField2 = 0;
 116             longField1 = 0L;
 117         }
 118     }
 119 
 120     static class TestWithoutStores {
 121         Object objectField1;
 122         Object objectField2;
 123         Object objectField3;
 124         int intField1;
 125         int intField2;
 126         long longField1;
 127     }
 128 
 129 }