static LOOKUP_HOST_CACHE: LazyLock<RwLock<HashMap<String, Vec<IpAddr>>>>Expand description
Map from hostname to IP addresses.
NOTE: sync RwLock is used, so it must not be held across .await
to avoid deadlocks.
See
https://docs.rs/tokio/1.40.0/tokio/sync/struct.Mutex.html#which-kind-of-mutex-should-you-use
and
https://stackoverflow.com/questions/63712823/why-do-i-get-a-deadlock-when-using-tokio-with-a-stdsyncmutex.