Function idleBackoff

internal/carrier/client.go:658–669

idleBackoff returns how long a worker should sleep after n consecutive no-work polls. The wake channel is selected against this timer so any new TX (kick) cancels the sleep immediately and any held server-side long-poll receives downstream chunks without needing a fresh poll — so even a 1s tail does

(n int)

// long-poll receives downstream chunks without needing a fresh poll —
// so even a 1s tail does not add user-visible latency.
func idleBackoff(n int) time.Duration {
	switch {
	case n < 3:
		return pollIdleSleep
	case n < 10:
		return 50 * time.Millisecond
	case n < 30:
		return 250 * time.Millisecond
	default:
		return time.Second
	}
}

// pollOnce drains pending tx frames, POSTs them as a batch, and routes any
// response frames back to their sessions. Returns true if any work was done