multiprocessing: add sharedctypes, fix some stubtest cases (python#4282)

stdlib/3/multiprocessing/__init__.pyi

@@ -3,7 +3,7 @@ from typing import Any, Callable, Iterable, Optional, List, Union, Sequence, Tup
 from typing_extensions import Literal
 from ctypes import _CData
 from logging import Logger
-from multiprocessing import connection, pool, spawn, synchronize
+from multiprocessing import connection, pool, sharedctypes, spawn, synchronize
 from multiprocessing.context import (
     AuthenticationError as AuthenticationError,
     BaseContext,
@@ -26,7 +26,6 @@ if sys.version_info >= (3, 8):
 if sys.platform != "win32":
     from multiprocessing.context import ForkContext, ForkServerContext
 
-
 # N.B. The functions below are generated at runtime by partially applying
 # multiprocessing.context.BaseContext's methods, so the two signatures should
 # be identical (modulo self).
@@ -50,30 +49,21 @@ def Pool(processes: Optional[int] = ...,
          initargs: Iterable[Any] = ...,
          maxtasksperchild: Optional[int] = ...) -> pool.Pool: ...
 
-class Array:
-    value: Any = ...
-
-    def __init__(self, typecode_or_type: Union[str, Type[_CData]], size_or_initializer: Union[int, Sequence[Any]], *, lock: Union[bool, _LockLike] = ...) -> None: ...
-    def acquire(self) -> bool: ...
-    def release(self) -> bool: ...
-    def get_lock(self) -> _LockLike: ...
-    def get_obj(self) -> Any: ...
-
-    @overload
-    def __getitem__(self, key: int) -> Any: ...
-    @overload
-    def __getitem__(self, key: slice) -> List[Any]: ...
-    def __getslice__(self, start: int, stop: int) -> Any: ...
-    def __setitem__(self, key: int, value: Any) -> None: ...
-
+# Functions Array and Value are copied from context.pyi.
+# See https://github.com/python/typeshed/blob/ac234f25927634e06d9c96df98d72d54dd80dfc4/stdlib/2and3/turtle.pyi#L284-L291
+# for rationale
+def Array(
+    typecode_or_type: Any,
+    size_or_initializer: Union[int, Sequence[Any]],
+    *,
+    lock: bool = ...
+) -> sharedctypes._Array: ...
 
-class Value():
-    value: Any = ...
-    def __init__(self, typecode_or_type: Union[str, Type[_CData]], *args: Any, lock: Union[bool, _LockLike] = ...) -> None: ...
-    def get_lock(self) -> _LockLike: ...
-    def get_obj(self) -> Any: ...
-    def acquire(self) -> bool: ...
-    def release(self) -> bool: ...
+def Value(
+    typecode_or_type: Any,
+    *args: Any,
+    lock: bool = ...
+) -> sharedctypes._Value: ...
 
 # ----- multiprocessing function stubs -----
 def allow_connection_pickling() -> None: ...

stdlib/3/multiprocessing/context.pyi

@@ -1,5 +1,6 @@
 from logging import Logger
 import multiprocessing
+from multiprocessing import sharedctypes
 from multiprocessing import synchronize
 from multiprocessing import queues
 from multiprocessing.process import BaseProcess
@@ -73,23 +74,21 @@ class BaseContext(object):
     def RawArray(self, typecode_or_type: Any, size_or_initializer: Union[int, Sequence[Any]]) -> Any: ...
     # TODO: typecode_or_type param is a ctype with a base class of _SimpleCData or array.typecode Need to figure out
     # how to handle the ctype
-    # TODO: change return to Value once a stub exists in multiprocessing.sharedctypes
     def Value(
         self,
         typecode_or_type: Any,
         *args: Any,
         lock: bool = ...
-    ) -> Any: ...
+    ) -> sharedctypes._Value: ...
     # TODO: typecode_or_type param is a ctype with a base class of _SimpleCData or array.typecode Need to figure out
     # how to handle the ctype
-    # TODO: change return to Array once a stub exists in multiprocessing.sharedctypes
     def Array(
         self,
         typecode_or_type: Any,
         size_or_initializer: Union[int, Sequence[Any]],
         *,
         lock: bool = ...
-    ) -> Any: ...
+    ) -> sharedctypes._Array: ...
     def freeze_support(self) -> None: ...
     def get_logger(self) -> Logger: ...
     def log_to_stderr(self, level: Optional[str] = ...) -> Logger: ...

stdlib/3/multiprocessing/sharedctypes.pyi

@@ -0,0 +1,42 @@
+from ctypes import _CData
+from typing import Any, List, Optional, Sequence, Type, Union, overload
+
+from multiprocessing.synchronize import _LockLike
+from multiprocessing.context import BaseContext
+
+class _Array:
+    value: Any = ...
+
+    def __init__(self, typecode_or_type: Union[str, Type[_CData]], size_or_initializer: Union[int, Sequence[Any]], *, lock: Union[bool, _LockLike] = ...) -> None: ...
+    def acquire(self) -> bool: ...
+    def release(self) -> bool: ...
+    def get_lock(self) -> _LockLike: ...
+    def get_obj(self) -> Any: ...
+
+    @overload
+    def __getitem__(self, key: int) -> Any: ...
+    @overload
+    def __getitem__(self, key: slice) -> List[Any]: ...
+    def __getslice__(self, start: int, stop: int) -> Any: ...
+    def __setitem__(self, key: int, value: Any) -> None: ...
+
+class _Value():
+    value: Any = ...
+    def __init__(self, typecode_or_type: Union[str, Type[_CData]], *args: Any, lock: Union[bool, _LockLike] = ...) -> None: ...
+    def get_lock(self) -> _LockLike: ...
+    def get_obj(self) -> Any: ...
+    def acquire(self) -> bool: ...
+    def release(self) -> bool: ...
+
+def Array(
+    typecode_or_type: Union[str, Type[_CData]],
+    size_or_initializer: Union[int, Sequence[Any]],
+    *,
+    lock: Union[bool, _LockLike] = ...,
+    ctx: Optional[BaseContext] = ...) -> _Array: ...
+
+def Value(
+    typecode_or_type: Union[str, Type[_CData]],
+    *args: Any,
+    lock: Union[bool, _LockLike] = ...,
+    ctx: Optional[BaseContext] = ...) -> _Value: ...