JNI Benchmarks

We provide the code for a small set of benchmarks to compare various approaches to solving common JNI use-cases and then present the results.

The benchmarks at present are:

1. com.evolvedbinary.jnibench.common.call - Benchmarks for Creating Objects with JNI (results).

2. com.evolvedbinary.jnibench.common.array - Benchmarks for Passing Arrays with JNI (results).

3. com.evolvedbinary.jnibench.common.bytearray, and com.evolvedbinary.jnibench.common.getputjni - Benchmarks for JNI Data Transfer.

Reproducing

If you want to run the code yourself, you need to have Java 8, Maven 3, and a C++ compiler that supports the C++ 11 standard. You can then simply run:

$ mvn clean compile package

In the target/ sub-directory, you will then find both a jni-benchmarks-1.0.0-SNAPSHOT-application folder and a jni-benchmarks-1.0.0-SNAPSHOT-application.zip file, you can use either of these. They both contain bash scripts in their bin/ sub-folders for Mac, Linux, Unix and batch scripts for Windows. These scripts will run a single iteration of the benchmark.

If you want to run multiple iterations and get a CSV file of the results, you can use benchmark-100.sh and/or benchmark-100-with-close.sh, or array-benchmark-100.sh.

JMH support

We have support for running the tests via JMH, see jmh-benchmarks.sh. You can also pass --help to the script to see JMH options.

Byte array benchmarks

There are two benchmarks, which are currently available only via JMH: ByteArrayFromNativeBenchmark and ByteArrayToNativeBenchmark. They can be run multiple times using jmh-benchmarks-parametrized.sh with:

./jmh-benchmarks-parametrized.sh -i 10 -b ByteArrayToNativeBenchmark -o results/ -f csv

The above command will run JMH with ByteArrayToNativeBenchmark benchmarks 10 times and store result in CSV files in results directory. You can also pass --help to the script to see additional JMH options that can be used.

Results can then be plotted using the process_byte_array_benchmarks_results.py script. For example, to produce results for the ByteArrayToNativeBenchmark benchmarks, you can run:

python3 process_byte_array_benchmarks_results.py -p results/ --param-name "Param: keySize" --chart-title "Performance comparison of passing byte array with {} bytes via JNI"

Command line parameter p expects a path to the directory with the JMH result CSV files from running the benchmarks with jmh-benchmarks-parametrized.sh. The {} in the chart-title parameter will be replaced by the value from the param-name column.

Other Resources

1. Java Foreign Interface prototype and performance results in RocksJava (i.e. Panama) - https://rocksdb.org/blog/2024/02/20/foreign-function-interface.html
2. RocksJava API Performance Improvements - https://rocksdb.org/blog/2023/11/06/java-jni-benchmarks.html