You also have EONESHOT which means that the event monitor is automatically removed after it's triggered. It depends on the design of your concurrency model. F

You also have EONESHOT which means that the event monitor is automatically removed after it's triggered. It depends on the design of your concurrency model. For event based systems, you may prefer level-triggered notifications. That's because you want to trigger the callback any time data is available. For fiber/green-thread based systems, you may prefer edge-triggered notifications, and often typically one-shot (e.g. EONESHOT). That's because someone called `wait_until_readable` and when that function returns, they are done. If they want to wait again, they will call the function again.