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.Fork;
 28 import org.openjdk.jmh.annotations.Measurement;
 29 import org.openjdk.jmh.annotations.Mode;
 30 import org.openjdk.jmh.annotations.OutputTimeUnit;
 31 import org.openjdk.jmh.annotations.Warmup;
 32 
 33 import java.util.concurrent.TimeUnit;
 34 
 35 /**
 36  * Tests how well the JVM can remove stores after allocation of objects.
 37  */
 38 @BenchmarkMode(Mode.AverageTime)
 39 @OutputTimeUnit(TimeUnit.NANOSECONDS)
 40 @Warmup(iterations = 4, time = 2, timeUnit = TimeUnit.SECONDS)
 41 @Measurement(iterations = 4, time = 2, timeUnit = TimeUnit.SECONDS)
 42 @Fork(value = 3)
 43 public class PostAllocationStores {
 44 
 45     /** Tests allocation with explicit stores of null/zero to all fields. */
 46     @Benchmark
 47     public Object testAllocationWithNullStores() throws Exception {
 48         return new TestWithNullStores();
 49     }
 50 
 51     /**
 52      * Tests allocation with explicit stores of non-null/non-zero to all fields. This test exists as a complement to the
 53      * one above.
 54      */
 55     @Benchmark
 56     public Object testAllocationWithNonNullStores() throws Exception {
 57         return new TestWithNonNullStores();
 58     }
 59 
 60     /** Tests allocation with explicit stores of null/zero to all fields, where all fields are volatile. */
 61     @Benchmark
 62     public Object testAllocationWithNullVolatileStores() throws Exception {
 63         return new TestWithNullVolatileStores();
 64     }
 65 
 66     /** Tests allocation without any explicit stores to any fields. */
 67     @Benchmark
 68     public Object testAllocationWithoutStores() throws Exception {
 69         return new TestWithoutStores();
 70     }
 71 
 72     static class TestWithNullStores {
 73         Object objectField1;
 74         Object objectField2;
 75         Object objectField3;
 76         int intField1;
 77         int intField2;
 78         long longField1;
 79 
 80         public TestWithNullStores() {
 81             objectField1 = null;
 82             objectField2 = null;
 83             objectField3 = null;
 84             intField1 = 0;
 85             intField2 = 0;
 86             longField1 = 0L;
 87         }
 88     }
 89 
 90     static class TestWithNonNullStores {
 91         Object objectField1;
 92         Object objectField2;
 93         Object objectField3;
 94         int intField1;
 95         int intField2;
 96         long longField1;
 97 
 98         @SuppressWarnings("initialization")
 99         public TestWithNonNullStores() {
100             objectField1 = this;
101             objectField2 = this;
102             objectField3 = this;
103             intField1 = 4;
104             intField2 = 7;
105             longField1 = 2L;
106         }
107     }
108 
109     static class TestWithNullVolatileStores {
110         volatile Object objectField1;
111         volatile Object objectField2;
112         volatile Object objectField3;
113         volatile int intField1;
114         volatile int intField2;
115         volatile long longField1;
116 
117         public TestWithNullVolatileStores() {
118             objectField1 = null;
119             objectField2 = null;
120             objectField3 = null;
121             intField1 = 0;
122             intField2 = 0;
123             longField1 = 0L;
124         }
125     }
126 
127     static class TestWithoutStores {
128         Object objectField1;
129         Object objectField2;
130         Object objectField3;
131         int intField1;
132         int intField2;
133         long longField1;
134     }
135 
136 }