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.java.util.stream.tasks.IntegerDuplicate; 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 import org.openjdk.jmh.annotations.Scope; 30 import org.openjdk.jmh.annotations.Setup; 31 import org.openjdk.jmh.annotations.State; 32 33 import java.util.Arrays; 34 import java.util.Collections; 35 import java.util.concurrent.TimeUnit; 36 import java.util.concurrent.atomic.LongAdder; 37 38 /** 39 * This benchmark assesses flatMap() performance. 40 */ 41 @BenchmarkMode(Mode.Throughput) 42 @OutputTimeUnit(TimeUnit.SECONDS) 43 @State(Scope.Thread) 44 public class Lambda { 45 46 /** 47 * Implementation notes: 48 * - parallel versions need to use special sink to get the values 49 */ 50 51 private IntegerDuplicateProblem problem; 52 53 @Setup 54 public void setup() { 55 problem = new IntegerDuplicateProblem(); 56 } 57 58 @Benchmark 59 public long lambda_seq_inner() { 60 return Arrays.stream(problem.get()).flatMap(k -> Collections.nCopies(2, k).stream()) 61 .collect(LongAdder::new, LongAdder::add, (la1, la2) -> la1.add(la2.sum())).sum(); 62 } 63 64 @Benchmark 65 public long lambda_par_inner() { 66 return Arrays.stream(problem.get()).parallel().flatMap(k -> Collections.nCopies(2, k).stream()) 67 .collect(LongAdder::new, LongAdder::add, (la1, la2) -> la1.add(la2.sum())).sum(); 68 } 69 70 }