Issue 24315: Make collections.abc.Coroutine derived from Awaitable
diff --git a/Lib/_collections_abc.py b/Lib/_collections_abc.py
index 0ca7deb..a02b219 100644
--- a/Lib/_collections_abc.py
+++ b/Lib/_collections_abc.py
@@ -75,7 +75,7 @@
return NotImplemented
-class _CoroutineMeta(ABCMeta):
+class _AwaitableMeta(ABCMeta):
def __instancecheck__(cls, instance):
# 0x80 = CO_COROUTINE
@@ -92,7 +92,26 @@
return super().__instancecheck__(instance)
-class Coroutine(metaclass=_CoroutineMeta):
+class Awaitable(metaclass=_AwaitableMeta):
+
+ __slots__ = ()
+
+ @abstractmethod
+ def __await__(self):
+ yield
+
+ @classmethod
+ def __subclasshook__(cls, C):
+ if cls is Awaitable:
+ for B in C.__mro__:
+ if "__await__" in B.__dict__:
+ if B.__dict__["__await__"]:
+ return True
+ break
+ return NotImplemented
+
+
+class Coroutine(Awaitable):
__slots__ = ()
@@ -126,27 +145,19 @@
else:
raise RuntimeError("coroutine ignored GeneratorExit")
-
-class Awaitable(metaclass=_CoroutineMeta):
-
- __slots__ = ()
-
- @abstractmethod
- def __await__(self):
- yield
-
@classmethod
def __subclasshook__(cls, C):
- if cls is Awaitable:
- for B in C.__mro__:
- if "__await__" in B.__dict__:
- if B.__dict__["__await__"]:
- return True
- break
+ if cls is Coroutine:
+ mro = C.__mro__
+ for method in ('__await__', 'send', 'throw', 'close'):
+ for base in mro:
+ if method in base.__dict__:
+ break
+ else:
+ return NotImplemented
+ return True
return NotImplemented
-Awaitable.register(Coroutine)
-
class AsyncIterable(metaclass=ABCMeta):
diff --git a/Lib/test/test_asyncio/test_pep492.py b/Lib/test/test_asyncio/test_pep492.py
index e25e257..8fc6cba 100644
--- a/Lib/test/test_asyncio/test_pep492.py
+++ b/Lib/test/test_asyncio/test_pep492.py
@@ -97,18 +97,14 @@
finally:
f.close() # silence warning
- class FakeCoro(collections.abc.Coroutine):
+ # Test that asyncio.iscoroutine() uses collections.abc.Coroutine
+ class FakeCoro:
def send(self, value): pass
def throw(self, typ, val=None, tb=None): pass
+ def close(self): pass
+ def __await__(self): yield
- fc = FakeCoro()
- try:
- self.assertTrue(asyncio.iscoroutine(fc))
- finally:
- # To make sure that ABCMeta caches are freed
- # from FakeCoro ASAP.
- fc = FakeCoro = None
- support.gc_collect()
+ self.assertTrue(asyncio.iscoroutine(FakeCoro()))
if __name__ == '__main__':
diff --git a/Lib/test/test_collections.py b/Lib/test/test_collections.py
index ec86466..dc79b69 100644
--- a/Lib/test/test_collections.py
+++ b/Lib/test/test_collections.py
@@ -496,6 +496,8 @@
return value
def throw(self, typ, val=None, tb=None):
super().throw(typ, val, tb)
+ def __await__(self):
+ yield
non_samples = [None, int(), gen(), object()]
for x in non_samples:
@@ -515,13 +517,7 @@
self.assertIsInstance(c, Awaitable)
c.close() # awoid RuntimeWarning that coro() was not awaited
- class CoroLike:
- def send(self, value):
- pass
- def throw(self, typ, val=None, tb=None):
- pass
- def close(self):
- pass
+ class CoroLike: pass
Coroutine.register(CoroLike)
self.assertTrue(isinstance(CoroLike(), Awaitable))
self.assertTrue(issubclass(CoroLike, Awaitable))
@@ -548,6 +544,8 @@
return value
def throw(self, typ, val=None, tb=None):
super().throw(typ, val, tb)
+ def __await__(self):
+ yield
non_samples = [None, int(), gen(), object(), Bar()]
for x in non_samples:
@@ -567,6 +565,28 @@
self.assertIsInstance(c, Coroutine)
c.close() # awoid RuntimeWarning that coro() was not awaited
+ class CoroLike:
+ def send(self, value):
+ pass
+ def throw(self, typ, val=None, tb=None):
+ pass
+ def close(self):
+ pass
+ def __await__(self):
+ pass
+ self.assertTrue(isinstance(CoroLike(), Coroutine))
+ self.assertTrue(issubclass(CoroLike, Coroutine))
+
+ class CoroLike:
+ def send(self, value):
+ pass
+ def close(self):
+ pass
+ def __await__(self):
+ pass
+ self.assertFalse(isinstance(CoroLike(), Coroutine))
+ self.assertFalse(issubclass(CoroLike, Coroutine))
+
def test_Hashable(self):
# Check some non-hashables
non_samples = [bytearray(), list(), set(), dict()]