Hey guys. I have an issue with nested withTimeouts...

# coroutines

[gregschlom]

Hey guys. I have an issue with nested withTimeouts. Here’s some example code:

val channel = Channel<Int>()

    // this blocks indefinitely if the channel is empty
    suspend fun nexValue(): Int {
        println("Waiting for next value ")
        return channel.receive()
    }

    // same as nextValue(), but returns null after the timeout expires
    suspend fun nextValueWithTimout(t: Long): Int? {
        return withTimeoutOrNull(t) { nexValue() }
    }

    suspend fun longOperation() {
        println("Starting long operation")
        while (true) {
            val v = nextValueWithTimout(1000)
            if (v == null) {
                println("timed out")
                // Nothing was received in our channel.
                // Do some other work while we wait for the value to arrive. Maybe we want to re-try sending
                // a message to our value producer for example
            }
            if (v == 42) return
        }
    }

    @Test
    fun main() = runBlocking {
        // This never returns. Instead we get stuck in an infinite loop in the while() above
        withTimeout(5000) {
            longOperation()
        }
    }