matttproud.com (blog)
The context API is a critical foundation for modern Go development. This is especially the case with APIs that use concurrency under the hood or perform distributed operations. Given this, I would like to do a deep dive on several topics around the context API. I expect this post to be the first of several. In this one, I cover contexts and program scopes.
Program scope and contexts sound like a mundane topic, but a fair bit of confusion arises with contexts in industry. The most recent example I saw was this post on Reddit: Should contexts be used for long-running operations?
So why is this even a question at all? It’s one frequently asked; I see it raised in code review more than I am comfortable admitting. The answer lies in a combination of history and technical documentation.1
The first time the necessity for something similar to the context API was hinted at was in a March 2014 blog post entitled: Go Concurrency Patterns: Pipelines and cancellation. It teased how something like context API could be used to make distributed and concurrent operations behave synchronously, which is foundational in good API design in Go.
