```{index} single: one_event (Event) ``` ```{index} single: Event::one_event ``` # one_event `one_event($timeout)`: run one callback, waiting for an event if none is queued - at most `$timeout` seconds, 60 by default. Returns true if a callback ran. `loop` is built on it, but unlike `loop` it does not trap exceptions: a callback's `die` propagates out of `one_event`. One round: turn counted signals into events; if an event of priority better than 5 is queued, run it and return; otherwise wait for descriptors and timers (no longer than the next timer and `$timeout`), queue what happened, turn signals into events again, run the best queued event if there is one, and otherwise run an idle watcher.