pub async fn flush_all(timeout: Duration)Expand description
Best-effort flush of every live connection this process holds, so queued
fire-and-forget frames are written before a one-shot exit drops the runtime.
Each connection is bounded by timeout and they run concurrently, so the
call returns within ~timeout even if some peers are unreachable. The hot
path (Client::send/Client::send_from) stays fire-and-forget.