Re-organize directory structure (#4971)

See discussion in #2491

Co-authored-by: Ivan Levkivskyi <ilevkivskyi@dropbox.com>

stdlib/multiprocessing/dummy/__init__.pyi

@@ -0,0 +1,52 @@
+import array
+import threading
+import weakref
+from queue import Queue as Queue
+from typing import Any, Callable, Iterable, List, Mapping, Optional, Sequence
+
+JoinableQueue = Queue
+Barrier = threading.Barrier
+BoundedSemaphore = threading.BoundedSemaphore
+Condition = threading.Condition
+Event = threading.Event
+Lock = threading.Lock
+RLock = threading.RLock
+Semaphore = threading.Semaphore
+
+class DummyProcess(threading.Thread):
+    _children: weakref.WeakKeyDictionary[Any, Any]
+    _parent: threading.Thread
+    _pid: None
+    _start_called: int
+    exitcode: Optional[int]
+    def __init__(
+        self,
+        group: Any = ...,
+        target: Optional[Callable[..., Any]] = ...,
+        name: Optional[str] = ...,
+        args: Iterable[Any] = ...,
+        kwargs: Mapping[str, Any] = ...,
+    ) -> None: ...
+
+Process = DummyProcess
+
+class Namespace:
+    def __init__(self, **kwds: Any) -> None: ...
+    def __getattr__(self, __name: str) -> Any: ...
+    def __setattr__(self, __name: str, __value: Any) -> None: ...
+
+class Value:
+    _typecode: Any
+    _value: Any
+    value: Any
+    def __init__(self, typecode: Any, value: Any, lock: Any = ...) -> None: ...
+
+def Array(typecode: Any, sequence: Sequence[Any], lock: Any = ...) -> array.array[Any]: ...
+def Manager() -> Any: ...
+def Pool(
+    processes: Optional[int] = ..., initializer: Optional[Callable[..., Any]] = ..., initargs: Iterable[Any] = ...
+) -> Any: ...
+def active_children() -> List[Any]: ...
+def current_process() -> threading.Thread: ...
+def freeze_support() -> None: ...
+def shutdown() -> None: ...

stdlib/multiprocessing/dummy/connection.pyi

@@ -0,0 +1,39 @@
+from queue import Queue
+from types import TracebackType
+from typing import Any, List, Optional, Tuple, Type, TypeVar, Union
+
+families: List[None]
+
+_ConnectionT = TypeVar("_ConnectionT", bound=Connection)
+_ListenerT = TypeVar("_ListenerT", bound=Listener)
+_Address = Union[str, Tuple[str, int]]
+
+class Connection(object):
+    _in: Any
+    _out: Any
+    recv: Any
+    recv_bytes: Any
+    send: Any
+    send_bytes: Any
+    def __enter__(self: _ConnectionT) -> _ConnectionT: ...
+    def __exit__(
+        self, exc_type: Optional[Type[BaseException]], exc_val: Optional[BaseException], exc_tb: Optional[TracebackType]
+    ) -> None: ...
+    def __init__(self, _in: Any, _out: Any) -> None: ...
+    def close(self) -> None: ...
+    def poll(self, timeout: float = ...) -> bool: ...
+
+class Listener(object):
+    _backlog_queue: Optional[Queue[Any]]
+    @property
+    def address(self) -> Optional[Queue[Any]]: ...
+    def __enter__(self: _ListenerT) -> _ListenerT: ...
+    def __exit__(
+        self, exc_type: Optional[Type[BaseException]], exc_val: Optional[BaseException], exc_tb: Optional[TracebackType]
+    ) -> None: ...
+    def __init__(self, address: Optional[_Address] = ..., family: Optional[int] = ..., backlog: int = ...) -> None: ...
+    def accept(self) -> Connection: ...
+    def close(self) -> None: ...
+
+def Client(address: _Address) -> Connection: ...
+def Pipe(duplex: bool = ...) -> Tuple[Connection, Connection]: ...