"No matching benchmarks" when running JMH from main in eclipse

Question

I wanted to try out the new feature of JMH by running it as Java Application in eclipse. I imported and built jmh-samples project. Compiled classes ended in /jmh-samples/target/generated-sources/annotations, there are several JARs in /target/ and running microbenchmarks.jar from command line works as usual.

However when I execute main I always get

No matching benchmarks. Miss-spelled regexp?

Any ideas? I am using version 0.3

Answer 1

I was also facing the same problem, and I followed the tutorial here. That solved the issue.

Below are the steps I took:

• I used the code from the tutorial AS-IS to understand how it works.

• Then I just did mvn clean and install

• I saw all set of classes being created in target -> annotations -> <package path> -> generated
• Then I ran the BenchmarkRunner main() class and this worked.

Answer 2

jmh-dev@ is a better way to communicate this with the developers.

Few things to try:

1. Hijacking Main is probably not a good idea. Use Java API instead, like this sample.
2. Use -v extra to debug the pattern matching: either the filter regexp is incorrect, or there are no benchmarks to run.
3. If the regexp is incorrect, fix it.
4. If there are no benchmarks to match against, then there is a chance resources are not generated and/or picked up properly. Make sure target/classes/ is also available on classpath.

Answer 3

Okay, so looks like by default jmh looks for generated classes under META-INF/Microbenchmarks, which maven build puts under root of the project. However root of the eclipse project is not on the classpath, so executing it in IDE results in "no benchmarks found".

I got it running following way:

1. mvn clean package (using external maven installation, not embded in eclipse)
2. Right-click on jmh-samples project, select "Build Path -> Use as a source folder"
3. You can now run any of the benchmarks from jmh-samples as Java Application in eclipse

On the downside you get like 1000+ "errors" in Problems view, since eclipse gets confused with auto-generated files, but oh well, at least it works.