A benchmark is simply a test that is used to compare similar products. A computer benchmarking program works by running a series of well-defined tests on the PC to measure its performance.
Side-effects to avoid:
- Garbage collection;
- IO operations;
- Extra tools, like IDE, gradle, etc -> run directly on VM.
To optimize, include warm-up iterations.
JMH is a Java harness for building, running, and analysing nano/micro/milli/macro benchmarks written in Java and other languages targeting the JVM.
Benchmark methods are annotated with the @Benchmark annotation.
Benchmark options:
- Forks (
-f); - Warmup Iterations (
-wi); - Iterations (
-i); - Warmup Iteration Duration (
-w); - Iteration Duration (
-r); - Time Unit (
-u).
There is also a plugin for Gradle to run benchmarks: jmh-gradle-plugin.