Module drop 

Explicit, manually-invocable cleanup hook used to break reference cycles before Drop.

Many long-lived components register callbacks or handlers that retain strong references back to them, creating reference-count cycles that prevent Rust’s automatic destructor (Drop) from running. The CleanDrop trait provides an object-safe method, clean_drop, that can be called explicitly (e.g. during an orderly shutdown) to release such resources. Implementations should also call clean_drop from their Drop impl as a final safety net.

Design contract:

1. Idempotent – multiple calls must be safe.
2. Perform all externally-observable cleanup here (unregister handlers, abort tasks, clear callbacks, downgrade Rc/Arc references, etc.).

Traits

CleanDrop

Trait providing an explicit cleanup method that may be invoked prior to Drop.