| /* |
| * Copyright (c) 2017, 2017, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| |
| package micro.benchmarks; |
| |
| import java.util.ArrayList; |
| |
| import org.openjdk.jmh.annotations.Benchmark; |
| import org.openjdk.jmh.annotations.Level; |
| import org.openjdk.jmh.annotations.Scope; |
| import org.openjdk.jmh.annotations.Setup; |
| import org.openjdk.jmh.annotations.State; |
| import org.openjdk.jmh.annotations.Warmup; |
| |
| /** |
| * Benchmarks cost of ArrayList. |
| */ |
| public class ArrayListBenchmark extends BenchmarkBase { |
| |
| private static final int N = 100; |
| |
| @State(Scope.Benchmark) |
| public static class ThreadState { |
| final ArrayList<Integer> list = new ArrayList<>(N); |
| } |
| |
| @Benchmark |
| @Warmup(iterations = 20) |
| public void addBoxedAndClear(ThreadState state) { |
| for (int i = 0; i < N; ++i) { |
| state.list.add(i); |
| } |
| state.list.clear(); |
| } |
| |
| @Benchmark |
| @Warmup(iterations = 20) |
| public void addNullAndClear(ThreadState state) { |
| for (int i = 0; i < N; ++i) { |
| state.list.add(null); |
| } |
| state.list.clear(); |
| } |
| |
| @State(Scope.Benchmark) |
| public static class ClearedThreadState { |
| final ArrayList<Integer> list = new ArrayList<>(N); |
| |
| // We don't want to measure the cost of list clearing |
| @Setup(Level.Invocation) |
| public void beforeInvocation() { |
| list.clear(); |
| } |
| } |
| |
| @Benchmark |
| @Warmup(iterations = 20) |
| public void addNull(ClearedThreadState state) { |
| for (int i = 0; i < N; ++i) { |
| state.list.add(null); |
| } |
| } |
| } |