[inglor]

A singleton is basically a global variable and those aren't really important to "shim" in Go. Object method calls are pretty much the same conceptually as message passing but when you actually need to synchronize as you point out goroutines and channels make things much simpler. I think what this post was going for wasn't "use singletons", it was "look at these interesting threading issues that arise and how we address them in (non idiomatic) Go"

[pcwalton]

There's more that needs to be done if the goal is "look at these interesting threading issues that arise and how we address them in (non idiomatic) Go", because the initialization described in the post is broken.

Shared-memory multithreading is hard. Golang does not do much to prevent you from shooting yourself in the foot here, as this post proves. So use the abstractions wherever possible. In this case, Once correctly performs the atomics, and naive double-checked locking doesn't.