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.lang.invoke; 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.lang.invoke.MethodHandle; 34 import java.lang.invoke.MethodHandles; 35 import java.util.concurrent.TimeUnit; 36 37 /** 38 * Benchmark assesses the performance of MethodHandles.arrayElementSetter 39 * 40 * @author Aleksey Shipilev (aleksey.shipilev@oracle.com) 41 */ 42 @BenchmarkMode(Mode.AverageTime) 43 @OutputTimeUnit(TimeUnit.NANOSECONDS) 44 @State(Scope.Thread) 45 public class MethodHandlesArrayElementSetter { 46 47 /** 48 * Implementation notes: 49 * - creating simple array, and accessing the middle element 50 * - might have done iteration over array, but that will measure pipelining effects instead 51 * - volatile modifier on array breaks the DCE, which would otherwise eliminate the array store 52 * - the array is not shared to prevent true sharing 53 * - the array is large enough to prevent false sharing 54 */ 55 56 private static final int SIZE = 1024; 57 private static final int POS = SIZE/2; 58 59 private static MethodHandle mh; 60 private volatile int[] array; 61 62 @Setup 63 public void setup() throws Throwable { 64 array = new int[SIZE]; 65 for (int i = 0; i < SIZE; i++) { 66 array[i] = i; 67 } 68 mh = MethodHandles.arrayElementSetter(int[].class); 69 } 70 71 @Benchmark 72 public MethodHandle testCreate() { 73 return MethodHandles.arrayElementSetter(int[].class); 74 } 75 76 @Benchmark 77 public void baselineRaw() { 78 access(array, POS, 1); 79 } 80 81 @Benchmark 82 public void testSetter() throws Throwable { 83 mh.invoke(array, POS, 1); 84 } 85 86 public void access(int[] array, int pos, int v) { 87 array[pos] = v; 88 } 89 90 }