I'm running a coroutine that is reading from a receiverChannel. I've got this coroutine wrapped within a timeout and I want to get the number of messages it managed to read before the timeout cancels it. Here's what I have:
runBlocking {
val receivedMessages = withTimeoutOrNull(someTimeout) {
var found = 0
while (isActive && found < expectedAmount){
val message = incomming.receive()
// some filtering
found++
}
found
} ?: 0 // <- to not have null...
// Currently prints 0, but I want the messages it managed to read
println("I've received $receivedMessages messages")
}
I know I can use atomicInteger, but I would like to keep away from java specifics here
Local variables in a coroutine don't need to be atomic because of the happens-before guarantee even though there may be some thread swapping going on. Your code doesn't have any parallelism, so you can use the following:
runBlocking {
var receivedMessages = 0
withTimeoutOrNull(someTimeout) {
while (isActive && receivedMessages < expectedAmount){
val message = incomming.receive()
// some filtering
receivedMessages++
}
}
println("I've received $receivedMessages messages")
}
If you do have multiple children coroutines running in parallel, you can use a Mutex. More info here