What’s currently the best way to check for cancellation inside a suspend fun ? `coroutineScope { e...

# coroutines

[Patrick Steiger]

What’s currently the best way to check for cancellation inside a suspend fun ?

coroutineScope { ensureActive() }?

[ephemient]

no need for a temporary scope, `currentCoroutineContext().isActive()`/`.ensureActive()` will work

[Joffrey]

Note that this will not work in contexts where you don't have a job. For instance in suspend fun main, isActive will be false. It might be safer to use isActive on a temporary scope (with job) if you don't control the calling context, and you want the "not cancelled" semantics

[Joffrey]

https://github.com/Kotlin/kotlinx.coroutines/issues/3300

[hfhbd]

Or use suspend fun main() = coroutineScope {

[Patrick Steiger]

I think I’ll just wrap the whole suspend fun in coroutineScope — it just feels higher-level API and if context doesn’t have a job it will create one so I’ll be sure to call ensureActive in a scope with a job. In fact thinking of it I don’t know why every suspend fun does not get an implicit CoroutineScope with Job as a receiver by compiler magic but that’s another topic

[ephemient]

because not all suspend funs are for kotlinx.coroutines