A few microbenchmarks for JavaCPP using JMH

map.h

#include <map>

std::map<int,int> map;

void initMap(int n) {
    for (int i = 0; i < n; i++) {
        map[i] = n - i;
    }
}

int getMap(int i) {
    return map[i];
}

int sumMap() {
    int sum = 0;
    for (int i = 0, j = map[i]; j != 0; i++, j = map[i]) {
        sum += j;
    }
    return sum;
}

NativeBenchmark.java

/*
 * 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.bytedeco.javacpp;

import java.util.HashMap;
import org.bytedeco.javacpp.Loader;
import org.bytedeco.javacpp.annotation.*;
import org.openjdk.jmh.annotations.*;

@Platform(include = {"math.h", "unistd.h", "sort.h", "map.h"})
public class NativeBenchmark {
    static { Loader.load(); }

    @NoException
    public static class Compare extends FunctionPointer {
        public @Name("callbackCompare") int call(@ByPtr int i, @ByPtr int j) {
            return i < j ? -1 : i > j ? 1 : 0;
        }
    }

    @State(Scope.Thread)
    public static class JavaMap {
        HashMap<Integer,Integer> map = new HashMap();
        public JavaMap() {
            for (int i = 0; i < 100; i++) {
                map.put(i, 100 - i);
            }
        }
    }

    static int[] array = {0, 1, 2, 3, 4, 5, 6, 7};

    static {
        initMap(100);
    }

    @NoException
    public static native double exp(double x);

    @NoException
    public static native int getpid();

    @NoException
    @CriticalRegion
    public static native void callbackSort(int[] array);

    @NoException
    @CriticalRegion
    public static native void inlineSort(int[] array);

    @NoException
    @CriticalRegion
    public static native void nativeSort(int[] array);

    @NoException
    public static native void initMap(int n);

    @NoException
    public static native int getMap(int i);

    @NoException
    public static native int sumMap();

    @Benchmark
    @Fork(1)
    public double expBenchmark() {
        return exp(42);
    }

    @Benchmark
    @Fork(1)
    public int getpidBenchmark() {
        return getpid();
    }

    @Benchmark
    @Fork(1)
    public void callbackSortBenchmark() {
        callbackSort(array);
    }

    @Benchmark
    @Fork(1)
    public void inlineSortBenchmark() {
        inlineSort(array);
    }

    @Benchmark
    @Fork(1)
    public void nativeSortBenchmark() {
        nativeSort(array);
    }

    @Benchmark
    @Fork(1)
    public int javaSumBenchmark(JavaMap map) {
        int sum = 0;
        for (Integer i = 0, j = map.map.get(i); j != null; i++, j = map.map.get(i)) {
            sum += j;
        }
        return sum;
    }

    @Benchmark
    @Fork(1)
    public int nativeSumBenchmark() {
        return sumMap();
    }

    @Benchmark
    @Fork(1)
    public int sumBenchmark() {
        int sum = 0;
        for (int i = 0, j = getMap(i); j != 0; i++, j = getMap(i)) {
            sum += j;
        }
        return sum;
    }
}

pom.xml

<!--
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.
-->

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>org.sample</groupId>
    <artifactId>test</artifactId>
    <version>1.0</version>
    <packaging>jar</packaging>

    <name>JMH benchmark sample: Java</name>

    <!--
       This is the demo/sample template build script for building Java benchmarks with JMH.
       Edit as needed.
    -->

    <dependencies>
        <dependency>
            <groupId>org.bytedeco</groupId>
            <artifactId>javacpp</artifactId>
            <version>1.4.3</version>
        </dependency>
        <dependency>
            <groupId>org.openjdk.jmh</groupId>
            <artifactId>jmh-core</artifactId>
            <version>${jmh.version}</version>
        </dependency>
        <dependency>
            <groupId>org.openjdk.jmh</groupId>
            <artifactId>jmh-generator-annprocess</artifactId>
            <version>${jmh.version}</version>
            <scope>provided</scope>
        </dependency>
    </dependencies>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>

        <!--
            JMH version to use with this project.
          -->
        <jmh.version>1.21</jmh.version>

        <!--
            Java source/target to use for compilation.
          -->
        <javac.target>1.8</javac.target>

        <!--
            Name of the benchmark Uber-JAR to generate.
          -->
        <uberjar.name>benchmarks</uberjar.name>
    </properties>

    <build>
        <sourceDirectory>.</sourceDirectory>
        <plugins>
            <plugin>
                <groupId>org.bytedeco</groupId>
                <artifactId>javacpp</artifactId>
                <version>1.4.3</version>
                <dependencies>
                    <dependency>
                        <groupId>org.openjdk.jmh</groupId>
                        <artifactId>jmh-core</artifactId>
                        <version>${jmh.version}</version>
                    </dependency>
                </dependencies>
                <executions>
                    <execution>
                        <id>javacpp.compiler</id>
                        <phase>process-classes</phase>
                        <goals>
                            <goal>build</goal>
                        </goals>
                        <configuration>
                            <classOrPackageName>org.bytedeco.javacpp.*</classOrPackageName>
                            <includePath>${basedir}</includePath>
                        </configuration>
                    </execution>
                </executions>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.1</version>
                <configuration>
                    <compilerVersion>${javac.target}</compilerVersion>
                    <source>${javac.target}</source>
                    <target>${javac.target}</target>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-shade-plugin</artifactId>
                <version>2.2</version>
                <executions>
                    <execution>
                        <phase>package</phase>
                        <goals>
                            <goal>shade</goal>
                        </goals>
                        <configuration>
                            <finalName>${uberjar.name}</finalName>
                            <transformers>
                                <transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
                                    <mainClass>org.openjdk.jmh.Main</mainClass>
                                </transformer>
                            </transformers>
                            <filters>
                                <filter>
                                    <!--
                                        Shading signed JARs will fail without this.
                                        http://stackoverflow.com/questions/999489/invalid-signature-file-when-attempting-to-run-a-jar
                                    -->
                                    <artifact>*:*</artifact>
                                    <excludes>
                                        <exclude>META-INF/*.SF</exclude>
                                        <exclude>META-INF/*.DSA</exclude>
                                        <exclude>META-INF/*.RSA</exclude>
                                    </excludes>
                                </filter>
                            </filters>
                        </configuration>
                    </execution>
                </executions>
            </plugin>
        </plugins>
        <pluginManagement>
            <plugins>
                <plugin>
                    <artifactId>maven-clean-plugin</artifactId>
                    <version>2.5</version>
                </plugin>
                <plugin>
                    <artifactId>maven-deploy-plugin</artifactId>
                    <version>2.8.1</version>
                </plugin>
                <plugin>
                    <artifactId>maven-install-plugin</artifactId>
                    <version>2.5.1</version>
                </plugin>
                <plugin>
                    <artifactId>maven-jar-plugin</artifactId>
                    <version>2.4</version>
                </plugin>
                <plugin>
                    <artifactId>maven-javadoc-plugin</artifactId>
                    <version>2.9.1</version>
                </plugin>
                <plugin>
                    <artifactId>maven-resources-plugin</artifactId>
                    <version>2.6</version>
                </plugin>
                <plugin>
                    <artifactId>maven-site-plugin</artifactId>
                    <version>3.3</version>
                </plugin>
                <plugin>
                    <artifactId>maven-source-plugin</artifactId>
                    <version>2.2.1</version>
                </plugin>
                <plugin>
                    <artifactId>maven-surefire-plugin</artifactId>
                    <version>2.17</version>
                </plugin>
            </plugins>
        </pluginManagement>
    </build>

</project>

sort.h

#include <algorithm>
#include <stdlib.h>

extern "C" {
    int callbackCompare(int *i, int *j);

    struct Compare {
        bool operator() (int i, int j) { return i < j; }
    };

    int compare(int *i, int *j) {
        return i[0] < j[0] ? -1 : i[0] > j[0] ? 1 : 0;
    }
}

void callbackSort(int array[8]) {
    qsort(array, 8, sizeof(int), (int (*)(const void*, const void*))callbackCompare);
}

void inlineSort(int array[8]) {
    std::sort(array, array + 8, Compare());
}

void nativeSort(int array[8]) {
    qsort(array, 8, sizeof(int), (int (*)(const void*, const void*))compare);
}