Clone inner objects when cloning DirectButler

When cloning a DirectButler instance, clone all of its inner objects instead of just copying references to the top-level properties. This makes it safe to use the cloned objects concurrently from different threads. This is necessary for the Butler server and other services using DirectButler as a backend, since they have a separate thread for each incoming request.
lsst · Jan 9, 2024 · 4879269 · 4879269
1 parent d0bfb3f
commit 4879269
Show file tree

Hide file tree

Showing 2 changed files with 6 additions and 11 deletions.
diff --git a/python/lsst/daf/butler/direct_butler.py b/python/lsst/daf/butler/direct_butler.py
@@ -232,11 +232,12 @@ def _clone(
     ) -> DirectButler:
         # Docstring inherited
         defaults = RegistryDefaults(collections=collections, run=run, infer=inferDefaults, **kwargs)
+        registry = self._registry.copy(defaults)
 
         return DirectButler(
-            registry=self._registry.copy(defaults),
+            registry=registry,
             config=self._config,
-            datastore=self._datastore,
+            datastore=self._datastore.clone(registry.getDatastoreBridgeManager()),
             storageClasses=self.storageClasses,
         )
 

diff --git a/python/lsst/daf/butler/registry/sql_registry.py b/python/lsst/daf/butler/registry/sql_registry.py
@@ -275,7 +275,7 @@ def isWriteable(self) -> bool:
 
     def copy(self, defaults: RegistryDefaults | None = None) -> SqlRegistry:
         """Create a new `SqlRegistry` backed by the same data repository
-        and connection as this one, but independent defaults.
+        as this one, but independent defaults and database connection.
 
         Parameters
         ----------
@@ -288,19 +288,13 @@ def copy(self, defaults: RegistryDefaults | None = None) -> SqlRegistry:
         -------
         copy : `SqlRegistry`
             A new `SqlRegistry` instance with its own defaults.
-
-        Notes
-        -----
-        Because the new registry shares a connection with the original, they
-        also share transaction state (despite the fact that their `transaction`
-        context manager methods do not reflect this), and must be used with
-        care.
         """
         if defaults is None:
             # No need to copy, because `RegistryDefaults` is immutable; we
             # effectively copy on write.
             defaults = self.defaults
-        result = SqlRegistry(self._db, defaults, self._managers)
+        db = self._db.clone()
+        result = SqlRegistry(db, defaults, self._managers.clone(db))
         result.dimension_record_cache.load_from(self.dimension_record_cache)
         return result