Add multiprocessing.popen_spawn_win32 submodule (#8428)

stdlib/multiprocessing/popen_spawn_win32.pyi

@@ -0,0 +1,30 @@
+import sys
+from multiprocessing.process import BaseProcess
+from typing import ClassVar
+
+from .util import Finalize
+
+if sys.platform == "win32":
+    __all__ = ["Popen"]
+
+    TERMINATE: int
+    WINEXE: bool
+    WINSERVICE: bool
+    WINENV: bool
+
+    class Popen:
+        finalizer: Finalize
+        method: ClassVar[str]
+        pid: int
+        returncode: int | None
+        sentinel: int
+
+        def __init__(self, process_obj: BaseProcess) -> None: ...
+        def duplicate_for_child(self, handle: int) -> int: ...
+        def wait(self, timeout: float | None = ...) -> int | None: ...
+        def poll(self) -> int | None: ...
+        def terminate(self) -> None: ...
+
+        kill = terminate
+
+        def close(self) -> None: ...

stdlib/multiprocessing/reduction.pyi

@@ -27,9 +27,11 @@ def dump(obj, file, protocol: Any | None = ...) -> None: ...
 
 if sys.platform == "win32":
     if sys.version_info >= (3, 8):
-        def duplicate(handle, target_process: Any | None = ..., inheritable: bool = ..., *, source_process: Any | None = ...): ...
+        def duplicate(
+            handle: int, target_process: int | None = ..., inheritable: bool = ..., *, source_process: int | None = ...
+        ) -> int: ...
     else:
-        def duplicate(handle, target_process: Any | None = ..., inheritable: bool = ...): ...
+        def duplicate(handle: int, target_process: int | None = ..., inheritable: bool = ...) -> int: ...
 
     def steal_handle(source_pid, handle): ...
     def send_handle(conn, handle, destination_pid) -> None: ...

tests/stubtest_allowlists/darwin.txt

@@ -48,6 +48,9 @@ winsound
 ossaudiodev
 spwd
 
+# multiprocessing.popen_spawn_win32 exists on Darwin but fail to import
+multiprocessing.popen_spawn_win32
+
 # Platform differences that cannot be captured by the type system
 os.SCHED_[A-Z_]+
 posix.SCHED_[A-Z_]+

tests/stubtest_allowlists/linux.txt

@@ -37,6 +37,9 @@ msvcrt
 winreg
 winsound
 
+# multiprocessing.popen_spawn_win32 exists on Linux but fail to import
+multiprocessing.popen_spawn_win32
+
 # Aliases for OSError
 posix.error.characters_written
 resource.error.characters_written