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compumike • today at 5:40 PM • 1 reply • view on HN

Thanks. I know there's a `go vet` tool that's run as part of Kubernetes CI, and one of its checks is:

  lostcancel: check cancel func returned by context.WithCancel is called
I'm not 100% sure why `go vet` didn't catch this issue, but storing the cancelFn in the struct is probably part of the reason. Any Go experts know if that's the case?

Replies

cyberax • today at 6:23 PM

The cancel function escapes the function body, so static analysis can't detect it. There's another lint for that (containedctx), but I think it's off in K8s.

This is a serious tripping point with Go. There's no way to express: "this is a root context that I _want_ to store and only use to create derived contexts". Goroutines are also a source of problems, you can't easily say "I'm passing the ownership of this context to a goroutine".

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