#141 Checkstyle on Enterprise Code and Multi-Core Processors

[J.C. Hamlin]

The performance of Checkstyle on our project is not acceptable. It raises the build time in Eclipse from 9 minutes to over 20 minutes when it is turned on.

Windows 7 Enterprise 64-bit
Java 1.6.0_31 64-bit
MyEclipse 9.1 64-bit (based on Eclipse 3.6)
Checkstyle Plugin version 5.5.0.201111092104
Workstation: 12GB RAM, W3680 processor (12 cores at 3.33GHz)

We have about 30 projects, 29 smaller ones which Checkstyle runs on quickly, but the largest is 984 packages, 9526 source files, 11,753 classes, 1,634,770 lines of code and uses 180 third-party jar files and it takes Checkstyle about 10 minutes to analyze that project. During the time Checkstyle is analyzing it the CPU utilization is around 8-10% so Checkstyle is using only one core of twelve cores.

When Checkstyle is enabled, it will build in sequence, and add over 10 minutes to the total build time in Eclipse (changing it from 9 minutes to over 20 minutes).

While it was analyzing the big project, it was using only 1/12th of the available horsepower (1 of 12 cores) of the workstation it was running on. When multiple-cores are available, Checkstyle needs to make use of multiple cores in order to reduce the time it takes to analyze large projects. We want Checkstyle on for all builds, and it should use all 12 cores available to it to reduce the analysis time.

[Lars Koedderitzsch]

The limitation here is two-fold, and sadly neither are under influence of this tool:

1. Checkstyle core is inheritly single-threaded, all files passed to it are processed in sequence
2. (Afaik) Eclipse builds projects in sequence, thus the Checkstyle plugin also gets invoked in that sequence in a Eclipse build.

For a humungous project/workspace as yours I recommend using the eclipse-cs filter setting "Exclude unopened files" (found in the project setup for Checkstyle). This allows for on demand checking of files when they are opened - with only minimal resource strain.

[Lars Koedderitzsch]

Due to some "spring cleaning" I am closing this feature request as it is not in scope of the plugin. I can only facilitate the capabilities the core Checkstyle engine offers and multi-threaded execution is not one of them.

My previous comment offered some practical advise for handling large projects, so I guess this will have to make do.