Arvados

7696-pysdk-all-keep-service-types-wip is up for review. You will probably want to review this by reading each commit individually (git log -p). Adding the test to ensure writing threads == 1 regularly tickled a race condition, which I think has affected other Keep writing tests in the past. I finally tracked that down and fixed it, and ended up making several improvements to ThreadLimiter in the process. So there are three main commits:

• One to use Keep services of all types.
• One to test thread limiting, and fix the associated race condition.
• One to make various ThreadLimiter improvements that happened along the way of working on the previous commit.

I think they'll be easier to understand if you read each in isolation.