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Watching the <https://www.youtube.com/watch?v=EVLnWOcR0is|new video on kotlin coroutines 1.5> - I’m a little confused by the description of the `GlobalScope` delicate api legitimate use cases.

It’s my understanding that any time I would create a generic `CoroutineScope` , and then not cancel it, I can use `GlobalScope` instead. Is that correct? The main hesitation with the `GlobalScope` is simply that you can’t cancel it, and thus, it doesn’t lend itself well to hierarchical coroutines, right?.

There’s never a good reason to use GlobalScope in real, production code. The alternatives are always better. 

So lets say that I receive a push message in a service, and I want to send the push message to be handled to the `PushMessageRepository`. I don’t want to cancel the handling of the push message under any circumstances (I don’t think?).

I would normally call:
```GlobalScope.launch {
    pushMessageRepository.handleMessage(message)
}```
Instead, what should I do, and how does it produce different results?

<@U0KMMQA20> I agree that it's 99% of the time, but why "always"...?

If you have an object (singleton?) with a truly global lifecycle, ie it stays alive until the process ends, the use of GlobalScope if fine. What would be the advantage of creating your own non-cancalleble CoroutineScope?

Because as soon as you want to customize the dispatcher, or any other aspect of the default context for your global scope, you’ll just create a custom scope anyway. That has virtually no extra boilerplate. There’s no reason for GlobalScope to exist. It causes tons of problems, and solves none. 

I would also love to know the answer of how to craft alternatives, but there’s a lot more “Don’t use GlobalScope” and not much “Here’s what you should use”.

:slightly_smiling_face:
And, since GlobalScope is still there and not deprecated, when can/should you (still) use GlobalScope?

I’ll be more specific… I’m using a browser library, lots of callbacks. I’m wrapping it so that I can handle those callbacks asynchronously. So that callback function is not able to be a suspend function, I have to use a scope, and I’m just not seeing examples of how I’m supposed to do this.

almost all of the examples are;
```GlobalScope.launch { callback() }```

Here’s an example from StackOverflow: <https://stackoverflow.com/questions/63607484/kotlin-js-suspension-function-in-an-htmlbuttonelement-eventlistener> where the only answer is `GlobalScope.launch`

<@U0KMMQA20>
&gt; Because as soon as you want to customize the dispatcher, or any other aspect of the default context for your global scope, you’ll just create a custom scope anyway
But when you are using a member variable, you have to remember to create it as a `SupervisorJob`, as `Job` isn’t what you actually want most of the time in those cases.

Whenever I want a custom dispatcher for that use case, I just do `GlobalScope + Dispatchers.Main`. This isn’t a performance thing, it’s a convenience thing.