org.openjdk.jmh.samples.JMHSample_20_Annotations Maven / Gradle / Ivy

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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
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 * 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).
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 * 2 along with this work; if not, write to the Free Software Foundation,
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package org.openjdk.jmh.samples;

import org.openjdk.jmh.annotations.Fork;
import org.openjdk.jmh.annotations.GenerateMicroBenchmark;
import org.openjdk.jmh.annotations.Measurement;
import org.openjdk.jmh.annotations.OutputTimeUnit;
import org.openjdk.jmh.annotations.Scope;
import org.openjdk.jmh.annotations.State;
import org.openjdk.jmh.annotations.Warmup;
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;

@State(Scope.Thread)
@OutputTimeUnit(TimeUnit.MICROSECONDS)
@Fork(1)
public class JMHSample_20_Annotations {

    double x1 = Math.PI;

    /*
     * In addition to all the command line options usable at run time,
     * we have the annotations which can provide the reasonable defaults
     * for the some of the benchmarks. This is very useful when you are
     * dealing with lots of microbenchmarks, and some of them require
     * special treatment.
     *
     * Annotation can also be placed on class, to have the effect over
     * all the benchmark methods in the same class. The rule is, the
     * annotation in the closest scope takes the precedence: i.e.
     * the method-based annotation overrides class-based annotation,
     * etc.
     */

    @GenerateMicroBenchmark
    @Warmup(iterations = 5, time = 100, timeUnit = TimeUnit.MILLISECONDS)
    @Measurement(iterations = 5, time = 100, timeUnit = TimeUnit.MILLISECONDS)
    public double measure() {
        return Math.log(x1);
    }

    /*
     * ============================== HOW TO RUN THIS TEST: ====================================
     *
     * Note JMH honors the default annotation settings. You can always override
     * the defaults via the command line or API.
     *
     * You can run this test:
     *
     * a) Via the command line:
     *    $ mvn clean install
     *    $ java -jar target/microbenchmarks.jar ".*JMHSample_20.*"
     *
     * b) Via the Java API:
     */

    public static void main(String[] args) throws RunnerException {
        Options opt = new OptionsBuilder()
                .include(".*" + JMHSample_20_Annotations.class.getSimpleName() + ".*")
                .build();

        new Runner(opt).run();
    }

}