queue operation on the same coroutine - kotlin

Question

I'm receiving data through bluetooth with a custom protocol so I need to "decode" the packet and then show the result. I'm using a function of an object (singleton) to decode the bytes received but the communication is async so it's possible that I'm decoding the bytes/packet while I'm receiving other bytes. I need a solution to process the incoming data sequentially and not call the decode function while I'm already decoding a previous packet.
Here is my actual code. I tried to use mutex without success. Using a defined coroutineScope I should work on the same coroutine. Obviously the decode process have to run in background.
// Activity
bluetoothService.incomingData.observe(this, {
viewModel.getData(it) })
// ViewModel
private var coroutineJob = Job()
private val uiScope = CoroutineScope(Dispatchers.Default + coroutineJob)
fun getData(bytes: ByteArray) {
getDataSafeCall(bytes)
}
private fun getDataSafeCall(bytes: ByteArray) {
uiScopeJob = uiScope.launch {
Packet.processMessage(bytes.toUByteArray()).collect {
updateData(it)
}
}
}
// Packet Object
object Packet {
private val mutex = Mutex()
suspend fun processMessage(buffer: UByteArray) = flow {
mutex.withLock {
decode(buffer).collect { emit(it) }
}
}
private fun decode(buffer: UByteArray) = channelFlow {
// Here I'm processing my packet and then
offer()
}
}
EDIT: This is part of the Bluetooth Service if it helps to understand more, even if there's no problem receiving data.
// BluetoothService
class BluetoothService : Service() {
private val btChannel: BtChannel by inject()
private var socket: BluetoothSocket? = null
private val receivedLive = MutableLiveData<ByteArray>()
fun incomingData(): LiveData<ByteArray> {
if (socket != null) {
socket.let {
btChannel.read(socket).onEach
{
withContext(Dispatchers.Main) {
receivedLive.value = it
}
}.launchIn(CoroutineScope(Dispatchers.IO))
}
}
return receivedLive
}
}