I have a question about `StateFlow` on Kotlin/Native. Let’s say StateFlow is holding/passing an immu...

# kotlin-native

[Daniele B]

I have a question about StateFlow on Kotlin/Native.
Let’s say StateFlow is holding/passing an immutable data object, and it’s collected on the iOS side on Dispatchers.Main, to be used with SwiftUI.
On the Application Logic side, I’m processing/setting the new StateFlow values (by using the Kotlin copy function), inside a coroutine.
My question is:
according to the current Kotlin/Native multithreading system, should such coroutine where I am processing/setting the new StateFlow values run on Dispatchers.Main or it can also use a background thread (e.g. Dispatchers.Default)?
Being the value immutable, I wonder if StateFlow is able to provide thread safety under the hood, without having to care what is the thread where the new value is set.

[Thomas]

Unfortunately StateFlow cannot be frozen yet. See https://github.com/Kotlin/kotlinx.coroutines/issues/2138

[Daniele B]

@Thomas I thought you don’t need to freeze data which is immutable. In my case I am just dealing with immutable data.

[Thomas]

If you want to access something from multiple threads, it needs to be frozen

[Thomas]

https://play.kotlinlang.org/hands-on/Kotlin%20Native%20Concurrency/00_Introduction

[Thomas]

The problem here is that StateFlow itself does not support freezing, so it's not only about its values

[Daniele B]

ok I see, I hoped it was a sophisticated structure that could move immutable data around from one thread to the other one, without hassles