/* * Copyright (c) 2014, Oracle America, Inc. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: * * * Redistributions of source code must retain the above copyright notice, * this list of conditions and the following disclaimer. * * * Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * * Neither the name of Oracle nor the names of its contributors may be used * to endorse or promote products derived from this software without * specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF * THE POSSIBILITY OF SUCH DAMAGE. */ package org.openjdk.jmh.samples; import org.openjdk.jmh.annotations.Benchmark; import org.openjdk.jmh.annotations.BenchmarkMode; import org.openjdk.jmh.annotations.Fork; import org.openjdk.jmh.annotations.Measurement; import org.openjdk.jmh.annotations.Mode; import org.openjdk.jmh.annotations.OutputTimeUnit; import org.openjdk.jmh.annotations.Scope; import org.openjdk.jmh.annotations.Setup; import org.openjdk.jmh.annotations.State; import org.openjdk.jmh.annotations.Warmup; import org.openjdk.jmh.infra.Blackhole; import org.openjdk.jmh.runner.Runner; import org.openjdk.jmh.runner.RunnerException; import org.openjdk.jmh.runner.options.Options; import org.openjdk.jmh.runner.options.OptionsBuilder; import java.util.concurrent.TimeUnit; @BenchmarkMode(Mode.AverageTime) @OutputTimeUnit(TimeUnit.NANOSECONDS) @Warmup(iterations = 5, time = 1, timeUnit = TimeUnit.SECONDS) @Measurement(iterations = 5, time = 1, timeUnit = TimeUnit.SECONDS) @Fork(1) @State(Scope.Thread) public class JMHSample_28_BlackholeHelpers { /** * Sometimes you need the black hole not in @Benchmark method, but in * helper methods, because you want to pass it through to the concrete * implementation which is instantiated in helper methods. In this case, * you can request the black hole straight in the helper method signature. * This applies to both @Setup and @TearDown methods, and also to other * JMH infrastructure objects, like Control. * * Below is the variant of {@link org.openjdk.jmh.samples.JMHSample_08_DeadCode} * test, but wrapped in the anonymous classes. */ public interface Worker { void work(); } private Worker workerBaseline; private Worker workerRight; private Worker workerWrong; @Setup public void setup(final Blackhole bh) { workerBaseline = new Worker() { double x; @Override public void work() { // do nothing } }; workerWrong = new Worker() { double x; @Override public void work() { Math.log(x); } }; workerRight = new Worker() { double x; @Override public void work() { bh.consume(Math.log(x)); } }; } @Benchmark public void baseline() { workerBaseline.work(); } @Benchmark public void measureWrong() { workerWrong.work(); } @Benchmark public void measureRight() { workerRight.work(); } /* * ============================== HOW TO RUN THIS TEST: ==================================== * * You will see measureWrong() running on-par with baseline(). * Both measureRight() are measuring twice the baseline, so the logs are intact. * * You can run this test: * * a) Via the command line: * $ mvn clean install * $ java -jar target/benchmarks.jar JMHSample_28 * * b) Via the Java API: * (see the JMH homepage for possible caveats when running from IDE: * http://openjdk.java.net/projects/code-tools/jmh/) */ public static void main(String[] args) throws RunnerException { Options opt = new OptionsBuilder() .include(JMHSample_28_BlackholeHelpers.class.getSimpleName()) .build(); new Runner(opt).run(); } }