Add mixins module to asyncio (#6789)

Author: sobolevn

stdlib/VERSIONS

@@ -62,6 +62,7 @@ array: 2.7-
 ast: 2.7-
 asynchat: 2.7-
 asyncio: 3.4-
+asyncio.mixins: 3.10-
 asyncio.compat: 3.4-3.6
 asyncio.exceptions: 3.8-
 asyncio.format_helpers: 3.7-

stdlib/asyncio/mixins.pyi

@@ -0,0 +1,7 @@
+import threading
+from typing import NoReturn
+
+_global_lock: threading.Lock
+
+class _LoopBoundMixin:
+    def __init__(self, *, loop: NoReturn = ...) -> None: ...

tests/stubtest_allowlists/py36.txt

@@ -12,6 +12,7 @@ asyncio.runners  # Added in Python 3.7
 asyncio.staggered  # Added in Python 3.8
 asyncio.threads  # Added in Python 3.9
 asyncio.trsock  # Added in Python 3.8
+asyncio.mixins  # Added in Python 3.10
 builtins.str.maketrans
 cmath.log
 collections.AsyncGenerator.ag_await

tests/stubtest_allowlists/py37.txt

@@ -12,6 +12,7 @@ asyncio.futures.Future._callbacks  # Usually initialized from c object
 asyncio.staggered  # Added in Python 3.8
 asyncio.threads  # Added in Python 3.9
 asyncio.trsock  # Added in Python 3.8
+asyncio.mixins  # Added in Python 3.10
 builtins.dict.get
 builtins.str.maketrans
 cmath.log

tests/stubtest_allowlists/py38.txt

@@ -17,6 +17,7 @@ asyncio.Future._callbacks  # Usually initialized from c object
 asyncio.futures.Future.__init__  # Usually initialized from c object
 asyncio.futures.Future._callbacks  # Usually initialized from c object
 asyncio.threads  # Added in Python 3.9
+asyncio.mixins  # Added in Python 3.10
 builtins.dict.get
 collections.AsyncGenerator.ag_await
 collections.AsyncGenerator.ag_code

tests/stubtest_allowlists/py39.txt

@@ -19,6 +19,7 @@ asyncio.Future.__init__  # Usually initialized from c object
 asyncio.Future._callbacks  # Usually initialized from c object
 asyncio.futures.Future.__init__  # Usually initialized from c object
 asyncio.futures.Future._callbacks  # Usually initialized from c object
+asyncio.mixins  # Added in Python 3.10
 builtins.dict.get
 collections.AsyncGenerator.ag_await
 collections.AsyncGenerator.ag_code