# runOnce() Runs the event loop once, processing any currently-ready events. ``` func runOnce() ``` ## Discussion Corresponds to `event_base_loop(base, EVLOOP_ONCE)`. Used internally by each async method in [`Socket`](/documentation/Event/Socket) / [`ServerSocket`](/documentation/Event/ServerSocket) so that per-operation awaiters drive the loop forward without requiring a caller-managed [`run()`](/documentation/Event/EventLoop/run()) task. If no events are ready, libevent blocks until one becomes ready and then returns.