diff --git a/synapse/util/async_helpers.py b/synapse/util/async_helpers.py
index 943ad54456..0cbeb0c365 100644
--- a/synapse/util/async_helpers.py
+++ b/synapse/util/async_helpers.py
@@ -19,6 +19,7 @@ import collections
import inspect
import itertools
import logging
+import typing
from contextlib import asynccontextmanager
from typing import (
Any,
@@ -29,6 +30,7 @@ from typing import (
Collection,
Coroutine,
Dict,
+ Generator,
Generic,
Hashable,
Iterable,
@@ -398,7 +400,7 @@ class _LinearizerEntry:
# The number of things executing.
count: int
# Deferreds for the things blocked from executing.
- deferreds: collections.OrderedDict
+ deferreds: typing.OrderedDict["defer.Deferred[None]", Literal[1]]
class Linearizer:
@@ -717,30 +719,25 @@ def timeout_deferred(
return new_d
-# This class can't be generic because it uses slots with attrs.
-# See: https://github.com/python-attrs/attrs/issues/313
@attr.s(slots=True, frozen=True, auto_attribs=True)
-class DoneAwaitable: # should be: Generic[R]
+class DoneAwaitable(Awaitable[R]):
"""Simple awaitable that returns the provided value."""
- value: Any # should be: R
+ value: R
- def __await__(self) -> Any:
- return self
-
- def __iter__(self) -> "DoneAwaitable":
- return self
-
- def __next__(self) -> None:
- raise StopIteration(self.value)
+ def __await__(self) -> Generator[Any, None, R]:
+ yield None
+ return self.value
def maybe_awaitable(value: Union[Awaitable[R], R]) -> Awaitable[R]:
"""Convert a value to an awaitable if not already an awaitable."""
if inspect.isawaitable(value):
- assert isinstance(value, Awaitable)
return value
+ # For some reason mypy doesn't deduce that value is not Awaitable here, even though
+ # inspect.isawaitable returns a TypeGuard.
+ assert not isinstance(value, Awaitable)
return DoneAwaitable(value)
|
