Is there some way to get job from

CoroutineContext

by key and cancel it?

what if I want to retrieve concrete child job from context?

A CoroutineContext has (at most) one Job. To examine child-jobs, get the main/parent Job (like in my example) and access the

children

property on it.

I want to associate each started Job with some key to find and cancel them later. What is better: to have

Map<Any, Job>

, or to add new

Element

to

CoroutineContext

?

In my opinion, cache each Job (Deferred) returned by launch/async in a Map, like your first suggestion. An Element in CoroutineContext is not like a map. It is a Unique Type Set, ie you can have only one value of an Element-type in a CoroutineContext. This means, for example, you can't store 2 Jobs in a CoroutineContext.

I see

What exactly are you trying to achieve? What's the context of the stuff you are doing?

I want to cancel concrete Jobs in

CoroutineScope

that have been launched earlier. You can treat it as a system that can emit signals like start Job or stop Job by token. I can explain this better in DM, if You want.

If you want to cancel them from "outside", from some control coroutine that is launching them, then the simplest way is to store somewhere the result of the

launch { .. }

function that returns a

Job

that you can call

cancel()

on.

So I did =)