Is there a better way to "yield" in a suspend func...

# coroutines

[taer]

Is there a better way to "yield" in a suspend function other than a delay(1)? I have this loop

private suspend fun poll2() {
    while (true) {
      consumer.poll(Duration.ofMillis(500))
        .forEach {
            channel.send("ping")
          }
        }
    }
  }

Channel is a kotlin Channel. If consumer.poll returns empty, the foreach doesn't execute. So we don't ever execute any suspendable code, so this loops forever, not giving back the thread to the coroutine. If I add a delay(1) immediately preceeding the poll, then other coroutines get a chance to run. Is there a cheaper alternative to an arbitrary 1ms delay?

BTW, this is an attempt to wrap a Kafka consumer output into a easier to consume Kotlin channel.

[octylFractal]

yield()?

[taer]

haha.. i always assumed that was for generatory things

[Zach Klippenstein (he/him) [MOD]]

It is, but only in the context of the sequence { } builder. Confusing, I know.

[taer]

Awesome. That worked perfectly. And reminded me that a sequence might actually work better for this use case vs the current channel.

[octylFractal]

if you want to retain coroutine lib. suspension features, you'll want to use Flow instead

[octylFractal]

sequence is only internally suspend, it doesn't use suspend outside of the builder

[bdawg.io]

yield() is a generic suspend function that can be used on any suspension context. yield(value: T) is a function definition on the SequenceScope provided inside of sequence { } and iterator { }

[octylFractal]

*any coroutine suspension context. the suspend mechanism does not imply coroutines, e.g. you can't use yield() in sequence {}

[taer]

Thanks. We're using a buffered channel then creating flow's from that so we can have multiple flows with a single Kafka consumer(assuming bounds, etc)