multithreading-demo

Native Image Multithreading Demo

The demo is a Java program which does synchronous and asynchronous threads execution. Each thread loops through exactly the same array of integers and generates a stream of pseudorandom numbers. The program calculates the time taken to perform the task synchronously and asynchronously.

Multithreading demo is comprised of two sub-projects, each built with Maven: Multithreading Demo Oversized and Multithreading Demo Improved. The pom.xml file of each sub-project includes the Native Image Maven plugin, which instructs Maven to generate a native executable of a JAR file with all dependencies at the mvn package step.

The plugin also generates a report using the Native Image Build Reports feature in the target directory with useful visualizations and comprehensive insights into different metrics of the native executable and the build process itself.

<plugin>
    <groupId>org.graalvm.buildtools</groupId>
    <artifactId>native-maven-plugin</artifactId>
    <version>0.10.1</version>
    <extensions>true</extensions>
    <executions>
        <execution>
            <id>native</id>
            <goals>
                <goal>compile-no-fork</goal>
            </goals>
            <phase>package</phase>
        </execution>
    </executions>
    <configuration>
        <imageName>${imageName}</imageName>
        <fallback>false</fallback>
        <buildArgs>
            <buildArg>
            -H:+UnlockExperimentalVMOptions -H:+BuildReport --initialize-at-build-time
            </buildArg>
        </buildArgs>
        <agent>
            <enabled>true</enabled>
            <defaultMode>Standard</defaultMode>
        </agent>
    </configuration>
</plugin>

Preparation

1. Download and install the latest GraalVM JDK using SDKMAN!.

   sdk install java 22.0.1-graal

2. Download or clone the repository and navigate into the multithreading-demo/multithreading-demo-oversized_ directory:

   git clone https://github.com/graalvm/graalvm-demos

   cd multithreading-demo/multithreading-demo-oversized

Multithreading Demo Oversized

1. Build the project:

   mvn package

2. Run the project on a JVM or as a native image:

   java -jar target/multithreading-1.0-jar-with-dependencies.jar
   ./target/multithreading-image-oversized

Multithreading Demo Improved

Multithreading Demo Improved contains an enhanced version of the same program.

1. Change to the project directory:

   cd ..
   multithreading-demo-improved

2. Build the project:

   mvn package

3. Run the project on a JVM or as a native image:

   java -jar target/multithreading-1.0-jar-with-dependencies.jar
   ./target/multithreading-image-improved

Learn More

Learn how you can optimize a Java application by applying Profile-guided optimization (PGO) and inspect a profile using Native Image Build Reports.