How would a higher-order function in a companion object variable act when being called by multiple threads? Will Kotlin run the function in the caller thread or are objects somehow shared across threads? I need a provided for a thread's namespace and it would be much cleaner to have that provider be a higher-order companion object function but I'm unsure whether it will correctly call the provider from the thread

Objects are singletons, across threads. Calling a function makes it execute in the caller's thread. Companion objects are not relevant here at all

So I'm not mistaken to assume that a higher-order function in a class's companion object will be called by the thread accessing it?

A function, higher order or not, will execute in the thread calling it, yes.

Good to know, thanks

@diesieben07 The first rule of tautology club is the first rule of tautology club :troll: