chore: add comment

PureWhiteWu · Aug 17, 2023 · 571876d · 571876d
1 parent f313bb2
commit 571876d
Showing 1 changed file with 1 addition and 0 deletions.
diff --git a/src/lib.rs b/src/lib.rs
@@ -112,6 +112,7 @@ where
             expire_at: v.1,
             is_expired: now > v.1,
         };
+        // The reference must be dropped, or will cause a deadlock when do expire.
         drop(v);
         self.do_expire(now);
         Some(value)