Threadpool comment

[leon-barrett]

Hi. I am the author of Claypoole, and a friend pointed out that you're using it. That's great, and I'm super excited, so I had to check out your project! In looking at your usage, I noticed a minor point that might help improve your thread usage.

Alas, threadpools in Java aren't automatically garbage collected. In runner.clj, you create a threadpool but don't shut it down. That could potentially leak threads, leading to a growing number of threads sitting around. It's likely not an issue, as those threads go away when the process stops, but it could trip you up in a long-running process.

Instead of explicitly allocating the pool, you can just specify the pool size when using upmap. Then, an appropriately-sized pool will be allocated and cleaned up automatically.

(let [...
      results (->> test-nses
                   (threadpool/upmap 20 ...)
                   ...)
      ...]
  ...)

[jakepearson]

Thanks for the tip, added.