chore: import upstream snapshot with attribution

rllib/utils/threading.py

@@ -0,0 +1,34 @@
+from typing import Callable
+
+from ray.rllib.utils.annotations import OldAPIStack
+
+
+@OldAPIStack
+def with_lock(func: Callable) -> Callable:
+    """Use as decorator (@withlock) around object methods that need locking.
+
+    Note: The object must have a self._lock = threading.Lock() property.
+    Locking thus works on the object level (no two locked methods of the same
+    object can be called asynchronously).
+
+    Args:
+        func: The function to decorate/wrap.
+
+    Returns:
+        The wrapped (object-level locked) function.
+    """
+
+    def wrapper(self, *a, **k):
+        try:
+            with self._lock:
+                return func(self, *a, **k)
+        except AttributeError as e:
+            if "has no attribute '_lock'" in e.args[0]:
+                raise AttributeError(
+                    "Object {} must have a `self._lock` property (assigned "
+                    "to a threading.RLock() object in its "
+                    "constructor)!".format(self)
+                )
+            raise e
+
+    return wrapper