pub const RESERVED_LOOKUP_CEILING: usize = 1024;Expand description
Connections the blocking pool is sized to reserve a lookup slot for.
max_connections is an operator’s number and may be raised without limit (or
switched off entirely, which is what 0 means), while a thread is a real
resource. Past this ceiling the reservation is best-effort: connections still
get their slot, the pool just no longer has a thread standing by for every
one of them at the same instant.