Fix a bug that eviction listener's key-level locks are not removed

when immediate notification mode is used

Add more tests.

src/future/cache.rs

@@ -2009,6 +2009,10 @@ where
     fn set_expiration_clock(&self, clock: Option<crate::common::time::Clock>) {
         self.base.set_expiration_clock(clock);
     }
+
+    fn key_locks_map_is_empty(&self) -> bool {
+        self.base.key_locks_map_is_empty()
+    }
 }
 
 pub struct BlockingOp<'a, K, V, S>(&'a Cache<K, V, S>);
@@ -2164,6 +2168,7 @@ mod tests {
         assert!(!cache.contains_key(&"d"));
 
         verify_notification_vec(&cache, actual, &expected);
+        assert!(cache.key_locks_map_is_empty());
     }
 
     #[test]
@@ -2353,6 +2358,7 @@ mod tests {
         assert_eq!(cache.weighted_size(), 25);
 
         verify_notification_vec(&cache, actual, &expected);
+        assert!(cache.key_locks_map_is_empty());
     }
 
     #[tokio::test]

src/sync/cache.rs

@@ -2190,6 +2190,7 @@ mod tests {
             assert!(!cache.contains_key(&"d"));
 
             verify_notification_vec(&cache, actual, &expected, delivery_mode);
+            assert_with_mode!(cache.key_locks_map_is_empty(), delivery_mode);
         }
     }
 
@@ -2320,6 +2321,7 @@ mod tests {
             assert_eq_with_mode!(cache.weighted_size(), 25, delivery_mode);
 
             verify_notification_vec(&cache, actual, &expected, delivery_mode);
+            assert_with_mode!(cache.key_locks_map_is_empty(), delivery_mode);
         }
     }
 

src/sync/segment.rs

@@ -687,6 +687,13 @@ where
 
         exp_clock
     }
+
+    fn key_locks_map_is_empty(&self) -> bool {
+        self.inner
+            .segments
+            .iter()
+            .all(|seg| seg.key_locks_map_is_empty())
+    }
 }
 
 // For unit tests.
@@ -916,6 +923,7 @@ mod tests {
             assert!(!cache.contains_key(&"d"));
 
             verify_notification_vec(&cache, actual, &expected, delivery_mode);
+            assert_with_mode!(cache.key_locks_map_is_empty(), delivery_mode);
         }
     }
 
@@ -1065,6 +1073,7 @@ mod tests {
             assert_eq_with_mode!(cache.weighted_size(), 25, delivery_mode);
 
             verify_notification_vec(&cache, actual, &expected, delivery_mode);
+            assert_with_mode!(cache.key_locks_map_is_empty(), delivery_mode);
         }
     }
 

src/sync_base/base_cache.rs

@@ -2424,7 +2424,8 @@ where
         self.key_locks
             .as_ref()
             .map(|m| m.is_empty())
-            .unwrap_or_default()
+            // If key_locks is None, consider it is empty.
+            .unwrap_or(true)
     }
 }