Token.invalid with errno set.EventLoop.registerIdle
Register an idle watcher.
IDLE watchers fire once per loop iteration when no other events were dispatched (no I/O ready, no timers expired, no signals received). This happens regardless of what other watchers are registered.
Use IDLE for lightweight background work like cursor blinking or debounced rendering. For periodic tasks, prefer registerTimer().
Parameters
callback | Callback run when an iteration finishes with no dispatched work. |
Returns
New watcher token on success, or