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