org.openjdk.jmh.samples.JMHSample_24_Inheritance Maven / Gradle / Ivy

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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * 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.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * 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.
 *
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package org.openjdk.jmh.samples;

import org.openjdk.jmh.annotations.BenchmarkMode;
import org.openjdk.jmh.annotations.Fork;
import org.openjdk.jmh.annotations.GenerateMicroBenchmark;
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.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;

@BenchmarkMode(Mode.AverageTime)
@Fork(1)
public class JMHSample_24_Inheritance {

    /*
     * In very special circumstances, you might want to provide the benchmark
     * body in the (abstract) superclass, and specialize it with the concrete
     * pieces in the subclasses. Unfortunately, the annotation processors
     * limit our ways in figuring out whether there are subclasses to the class
     * annotated with @GMB.
     *
     * JMH has the provisional hack over annotation processors, which still
     * enables us to do this. The rule of thumb is: if some class has @GMB
     * method, then all the subclasses are also having the "synthetic"
     * @GMB method. The caveat is, because we only know the type hierarchy
     * during the compilation, it is only possible during the same compilation
     * session. That is, mixing in the subclass extending your benchmark class
     * *after* the JMH compilation would have no effect.
     *
     * Note how annotations now have three possible places. The same rule apply:
     * the lexically-closes annotation wins.
     */

    @State(Scope.Thread)
    @OutputTimeUnit(TimeUnit.NANOSECONDS)
    public static abstract class AbstractBenchmark {
        public int x = 42;

        @GenerateMicroBenchmark
        @Warmup(iterations = 5, time = 100, timeUnit = TimeUnit.MILLISECONDS)
        @Measurement(iterations = 5, time = 100, timeUnit = TimeUnit.MILLISECONDS)
        public double bench() {
            return doWork() * doWork();
        }

        protected abstract double doWork();
    }

    public static class BenchmarkLog extends AbstractBenchmark {
        @Override
        protected double doWork() {
            return Math.log(x);
        }
    }

    public static class BenchmarkSin extends AbstractBenchmark {
        @Override
        protected double doWork() {
            return Math.sin(x);
        }
    }

    public static class BenchmarkCos extends AbstractBenchmark {
        @Override
        protected double doWork() {
            return Math.sin(x);
        }
    }

    /*
     * ============================== HOW TO RUN THIS TEST: ====================================
     *
     * You can run this test:
     *
     * a) Via the command line:
     *    $ mvn clean install
     *    $ java -jar target/microbenchmarks.jar ".*JMHSample_24.*"
     *
     * b) Via the Java API:
     */

    public static void main(String[] args) throws RunnerException {
        Options opt = new OptionsBuilder()
                .include(".*" + JMHSample_24_Inheritance.class.getSimpleName() + ".*")
                .build();

        new Runner(opt).run();
    }

}