👀 Views: 86 💬 Answers: 1 📅 Created: 2025-06-15

kotlin coroutines sharedflow Kotlin

I'm facing a challenge with backpressure handling in my Kotlin application that utilizes `SharedFlow`. I'm using Kotlin 1.8 and `kotlinx.coroutines` version 1.6.0. I have defined a `SharedFlow` in my ViewModel to emit values from a network response, but I'm noticing that during high-frequency emissions, the UI doesn't update as expected, and I'm seeing a warning in the log: `Backpressure detected!`. Here's a simplified version of what I have: ```kotlin class MyViewModel : ViewModel() { private val _dataFlow = MutableSharedFlow<Data>(replay = 1) val dataFlow: SharedFlow<Data> = _dataFlow.asSharedFlow() init { fetchData() } private fun fetchData() { viewModelScope.launch { repeat(100) { i -> _dataFlow.emit(fetchFromNetwork(i)) delay(50) // Simulating a network call } } } } ``` In my Fragment, I'm collecting this flow in a coroutine like this: ```kotlin lifecycleScope.launch { viewModel.dataFlow.collect { data -> updateUI(data) } } ``` I expected the UI to reflect the latest data as it arrives, but instead, it seems to drop updates when the emission frequency is high. I've tried increasing the buffer size of `MutableSharedFlow`, but it didn't help with the UI updates. I also considered switching to `StateFlow`, but I don’t want to lose the ability to emit multiple values. What strategies can I implement to manage backpressure without losing data? Any insights into optimizing flow collection in this scenario would be greatly appreciated.