stdlib: add __slots__ (#14611)

stdlib/asyncio/events.pyi

@@ -73,6 +73,7 @@ class _TaskFactory(Protocol):
     def __call__(self, loop: AbstractEventLoop, factory: _CoroutineLike[_T], /) -> Future[_T]: ...
 
 class Handle:
+    __slots__ = ("_callback", "_args", "_cancelled", "_loop", "_source_traceback", "_repr", "__weakref__", "_context")
     _cancelled: bool
     _args: Sequence[Any]
     def __init__(
@@ -85,6 +86,7 @@ class Handle:
         def get_context(self) -> Context: ...
 
 class TimerHandle(Handle):
+    __slots__ = ["_scheduled", "_when"]
     def __init__(
         self,
         when: float,

stdlib/asyncio/protocols.pyi

@@ -6,21 +6,26 @@ from typing import Any
 __all__ = ("BaseProtocol", "Protocol", "DatagramProtocol", "SubprocessProtocol", "BufferedProtocol")
 
 class BaseProtocol:
+    __slots__ = ()
     def connection_made(self, transport: transports.BaseTransport) -> None: ...
     def connection_lost(self, exc: Exception | None) -> None: ...
     def pause_writing(self) -> None: ...
     def resume_writing(self) -> None: ...
 
 class Protocol(BaseProtocol):
+    # Need annotation or mypy will complain about 'Cannot determine type of "__slots__" in base class'
+    __slots__: tuple[()] = ()
     def data_received(self, data: bytes) -> None: ...
     def eof_received(self) -> bool | None: ...
 
 class BufferedProtocol(BaseProtocol):
+    __slots__ = ()
     def get_buffer(self, sizehint: int) -> ReadableBuffer: ...
     def buffer_updated(self, nbytes: int) -> None: ...
     def eof_received(self) -> bool | None: ...
 
 class DatagramProtocol(BaseProtocol):
+    __slots__ = ()
     def connection_made(self, transport: transports.DatagramTransport) -> None: ...  # type: ignore[override]
     # addr can be a tuple[int, int] for some unusual protocols like socket.AF_NETLINK.
     # Use tuple[str | Any, int] to not cause typechecking issues on most usual cases.
@@ -30,6 +35,7 @@ class DatagramProtocol(BaseProtocol):
     def error_received(self, exc: Exception) -> None: ...
 
 class SubprocessProtocol(BaseProtocol):
+    __slots__: tuple[()] = ()
     def pipe_data_received(self, fd: int, data: bytes) -> None: ...
     def pipe_connection_lost(self, fd: int, exc: Exception | None) -> None: ...
     def process_exited(self) -> None: ...

stdlib/asyncio/transports.pyi

@@ -8,6 +8,7 @@ from typing import Any
 __all__ = ("BaseTransport", "ReadTransport", "WriteTransport", "Transport", "DatagramTransport", "SubprocessTransport")
 
 class BaseTransport:
+    __slots__ = ("_extra",)
     def __init__(self, extra: Mapping[str, Any] | None = None) -> None: ...
     def get_extra_info(self, name: str, default: Any = None) -> Any: ...
     def is_closing(self) -> bool: ...
@@ -16,11 +17,13 @@ class BaseTransport:
     def get_protocol(self) -> BaseProtocol: ...
 
 class ReadTransport(BaseTransport):
+    __slots__ = ()
     def is_reading(self) -> bool: ...
     def pause_reading(self) -> None: ...
     def resume_reading(self) -> None: ...
 
 class WriteTransport(BaseTransport):
+    __slots__ = ()
     def set_write_buffer_limits(self, high: int | None = None, low: int | None = None) -> None: ...
     def get_write_buffer_size(self) -> int: ...
     def get_write_buffer_limits(self) -> tuple[int, int]: ...
@@ -32,13 +35,16 @@ class WriteTransport(BaseTransport):
     def can_write_eof(self) -> bool: ...
     def abort(self) -> None: ...
 
-class Transport(ReadTransport, WriteTransport): ...
+class Transport(ReadTransport, WriteTransport):
+    __slots__ = ()
 
 class DatagramTransport(BaseTransport):
+    __slots__ = ()
     def sendto(self, data: bytes | bytearray | memoryview, addr: _Address | None = None) -> None: ...
     def abort(self) -> None: ...
 
 class SubprocessTransport(BaseTransport):
+    __slots__ = ()
     def get_pid(self) -> int: ...
     def get_returncode(self) -> int | None: ...
     def get_pipe_transport(self, fd: int) -> BaseTransport | None: ...
@@ -47,4 +53,5 @@ class SubprocessTransport(BaseTransport):
     def kill(self) -> None: ...
 
 class _FlowControlMixin(Transport):
+    __slots__ = ("_loop", "_protocol_paused", "_high_water", "_low_water")
     def __init__(self, extra: Mapping[str, Any] | None = None, loop: AbstractEventLoop | None = None) -> None: ...

stdlib/asyncio/trsock.pyi

@@ -14,6 +14,7 @@ _WriteBuffer: TypeAlias = bytearray | memoryview
 _CMSG: TypeAlias = tuple[int, int, bytes]
 
 class TransportSocket:
+    __slots__ = ("_sock",)
     def __init__(self, sock: socket.socket) -> None: ...
     @property
     def family(self) -> int: ...