Function route_until_with_credit_stats 

pub fn route_until_with_credit_stats<const N: usize, W: WaitStrategy>(
    router: &FanoutRouter<N>,
    cfg: RouterLoopConfig,
    wait: &mut W,
    credit_stats: &mut CreditStats<N>,
    should_stop: impl FnMut() -> bool,
) -> RouterCounters

Run a fanout router until should_stop() returns true, returning aggregate counters.

If cfg.credit is enabled, credit_stats is updated in place.

Backpressure and blocking

• For broadcast routing, destination-full remains drop-on-full.
• For work-queue routing, backpressure policies can avoid dequeuing the next source message when no consumer can accept it.
• With BackpressurePolicy::Block, the router uses wake sections when present; if wake waits fail at runtime, the loop falls back to wait.wait().