Harden concurrency and resource lifecycle (#101)

crates/libremetaverse/src/inventory_manager.rs

@@ -774,6 +774,35 @@ impl fmt::Debug for InventoryManager {
 }
 
 impl InventoryManager {
+    /// Whether the manager's callback-expiry worker is still owned and may run.
+    #[must_use]
+    pub fn cleanup_worker_running(&self) -> bool {
+        mutex(&self.inner.cleanup_worker).is_some()
+    }
+
+    /// Total asynchronous inventory operations still awaiting a reply.
+    #[must_use]
+    pub fn pending_operation_count(&self) -> usize {
+        mutex(&self.inner.pending_created).len()
+            + mutex(&self.inner.pending_copied).len()
+            + mutex(&self.inner.pending_fetches)
+                .values()
+                .map(Vec::len)
+                .sum::<usize>()
+            + mutex(&self.inner.pending_task_replies)
+                .values()
+                .map(Vec::len)
+                .sum::<usize>()
+            + mutex(&self.inner.pending_offers).len()
+            + mutex(&self.inner.task_xfers).len()
+    }
+
+    /// Whether deterministic manager teardown has completed.
+    #[must_use]
+    pub fn is_disposed(&self) -> bool {
+        self.inner.disposed.load(Ordering::Acquire)
+    }
+
     pub(crate) fn native_from_inner(inner: Arc<InventoryManagerInner>) -> Self {
         Self { inner }
     }