Function session_expired_for_request 

pub fn session_expired_for_request(
    expiry_ms: Option<i64>,
    api_key: i16,
    now_ms: i64,
    last_reauth_start_ms: Option<i64>,
) -> bool

Whether a request must close the connection because its KIP-368 session has expired, as Kafka’s Processor.processCompletedReceives decides.

A session expires only strictly after its deadline, as in KafkaChannel.serverAuthenticationSessionExpired: a request at exactly expiry_ms is still served. Past the deadline the one exempt frame is a SaslHandshake (17) that reauthentication_begins accepts, because Kafka asks maybeBeginServerReauthentication before it checks the deadline. Every other frame closes, a SaslAuthenticate (36) with no handshake before it and a handshake inside the one-second interval included. Authentication phase admission is a separate gate, including during the re-authentication rounds.