I need to share a pool of `N` subscriptions betwee...

# coroutines

[tseisel]

I need to share a pool of N subscriptions between multiple one time subscribers. My current implementation uses BroadcastChannel s to keep active subscriptions to source `Flow`s. Whenever a new subscriber requests, the eldest subscription is terminated by cancelling the BroadcastChannel (LRU caching).

suspend fun getLastFoo(id: String): Foo {
  val broadcast: BroadcastChannel<Foo> = getCachedSusbcription(id) ?: initiateSubscription(id)
  return broadcast.consume { receive() }
}

fun initiateSubscription(id: String): BroadcastChannel<Foo> {
  val broadcast = getExpensiveFooFlow(id).broadcastIn(scope)
  putInCacheAndEvictEldest(id, broadcast)
  return broadcast
}

fun getExpensiveFooFlow(id: String): Flow<Foo> { ... }

I'd like to migrate my code to use Flow.stateIn, but StateFlow does not have a cancel function to unsubscribe the source flow. How to implement this use-case with StateFlow ?