refactor: improves lock handling and code clarity in session management

Moves lock acquisition for internal maps to after awaiting the dissociate operation to minimize lock contention and potential deadlocks. Refactors error matching for clarity and suppresses a Clippy lint warning to improve code maintainability.

Author: AkinoKaede

asport-client/src/connection/udp_session.rs

@@ -262,7 +262,7 @@ impl UdpSession {
             return;
         }
 
-        if let Err(_) = self.0.update.try_send(()) {
+        if self.0.update.try_send(()).is_err() {
             // Mark update as failed and log once
             if !self.0.update_failed.swap(true, Ordering::Relaxed) {
                 log::debug!(

asport-server/src/connection/mod.rs

@@ -80,6 +80,7 @@ impl Connection {
         }
     }
 
+    #[allow(clippy::too_many_arguments)]
     pub async fn handle(
         conn: Connecting,
         users: Arc<HashMap<Uuid, User>>,

asport-server/src/connection/udp_sessions.rs

@@ -268,9 +268,6 @@ impl UdpSessions {
                 auth = self.0.conn.auth,
             );
 
-            let mut addr_map_lock = self.0.assoc_id_addr_map.lock();
-            let mut activity_lock = self.0.session_last_activity.lock();
-
             for assoc_id in expired_assoc_ids {
                 // Send dissociate command to client
                 if let Err(err) = self.0.conn.dissociate(assoc_id).await {
@@ -282,9 +279,13 @@ impl UdpSessions {
                     );
                 }
 
-                // Remove from internal maps
-                addr_map_lock.remove_by_left(&assoc_id);
-                activity_lock.remove(&assoc_id);
+                // Remove from internal maps after awaiting
+                {
+                    let mut addr_map_lock = self.0.assoc_id_addr_map.lock();
+                    let mut activity_lock = self.0.session_last_activity.lock();
+                    addr_map_lock.remove_by_left(&assoc_id);
+                    activity_lock.remove(&assoc_id);
+                }
             }
         }
     }