mirror of
https://github.com/SickGear/SickGear.git
synced 2024-12-18 16:53:38 +00:00
681 lines
25 KiB
Python
681 lines
25 KiB
Python
"""Bridges between the `asyncio` module and Tornado IOLoop.
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.. versionadded:: 3.2
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This module integrates Tornado with the ``asyncio`` module introduced
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in Python 3.4. This makes it possible to combine the two libraries on
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the same event loop.
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.. deprecated:: 5.0
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While the code in this module is still used, it is now enabled
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automatically when `asyncio` is available, so applications should
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no longer need to refer to this module directly.
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.. note::
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Tornado is designed to use a selector-based event loop. On Windows,
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where a proactor-based event loop has been the default since Python 3.8,
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a selector event loop is emulated by running ``select`` on a separate thread.
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Configuring ``asyncio`` to use a selector event loop may improve performance
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of Tornado (but may reduce performance of other ``asyncio``-based libraries
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in the same process).
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"""
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import asyncio
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import atexit
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import concurrent.futures
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import errno
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import functools
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import select
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import socket
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import sys
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import threading
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import typing
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import warnings
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from tornado.gen import convert_yielded
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from tornado.ioloop import IOLoop, _Selectable
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from typing import Any, TypeVar, Awaitable, Callable, Union, Optional, List, Tuple, Dict
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if typing.TYPE_CHECKING:
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from typing import Set # noqa: F401
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from typing_extensions import Protocol
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class _HasFileno(Protocol):
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def fileno(self) -> int:
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pass
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_FileDescriptorLike = Union[int, _HasFileno]
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_T = TypeVar("_T")
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# Collection of selector thread event loops to shut down on exit.
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_selector_loops = set() # type: Set[AddThreadSelectorEventLoop]
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def _atexit_callback() -> None:
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for loop in _selector_loops:
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with loop._select_cond:
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loop._closing_selector = True
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loop._select_cond.notify()
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try:
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loop._waker_w.send(b"a")
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except BlockingIOError:
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pass
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# If we don't join our (daemon) thread here, we may get a deadlock
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# during interpreter shutdown. I don't really understand why. This
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# deadlock happens every time in CI (both travis and appveyor) but
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# I've never been able to reproduce locally.
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loop._thread.join()
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_selector_loops.clear()
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atexit.register(_atexit_callback)
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if sys.version_info >= (3, 10):
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def _get_event_loop() -> asyncio.AbstractEventLoop:
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try:
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return asyncio.get_running_loop()
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except RuntimeError:
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pass
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return asyncio.get_event_loop_policy().get_event_loop()
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else:
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from asyncio import get_event_loop as _get_event_loop
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class BaseAsyncIOLoop(IOLoop):
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def initialize( # type: ignore
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self, asyncio_loop: asyncio.AbstractEventLoop, **kwargs: Any
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) -> None:
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# asyncio_loop is always the real underlying IOLoop. This is used in
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# ioloop.py to maintain the asyncio-to-ioloop mappings.
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self.asyncio_loop = asyncio_loop
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# selector_loop is an event loop that implements the add_reader family of
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# methods. Usually the same as asyncio_loop but differs on platforms such
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# as windows where the default event loop does not implement these methods.
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self.selector_loop = asyncio_loop
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if hasattr(asyncio, "ProactorEventLoop") and isinstance(
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asyncio_loop, asyncio.ProactorEventLoop # type: ignore
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):
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# Ignore this line for mypy because the abstract method checker
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# doesn't understand dynamic proxies.
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self.selector_loop = AddThreadSelectorEventLoop(asyncio_loop) # type: ignore
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# Maps fd to (fileobj, handler function) pair (as in IOLoop.add_handler)
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self.handlers = {} # type: Dict[int, Tuple[Union[int, _Selectable], Callable]]
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# Set of fds listening for reads/writes
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self.readers = set() # type: Set[int]
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self.writers = set() # type: Set[int]
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self.closing = False
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# If an asyncio loop was closed through an asyncio interface
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# instead of IOLoop.close(), we'd never hear about it and may
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# have left a dangling reference in our map. In case an
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# application (or, more likely, a test suite) creates and
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# destroys a lot of event loops in this way, check here to
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# ensure that we don't have a lot of dead loops building up in
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# the map.
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#
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# TODO(bdarnell): consider making self.asyncio_loop a weakref
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# for AsyncIOMainLoop and make _ioloop_for_asyncio a
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# WeakKeyDictionary.
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for loop in IOLoop._ioloop_for_asyncio.copy():
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if loop.is_closed():
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try:
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del IOLoop._ioloop_for_asyncio[loop]
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except KeyError:
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pass
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# Make sure we don't already have an IOLoop for this asyncio loop
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existing_loop = IOLoop._ioloop_for_asyncio.setdefault(asyncio_loop, self)
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if existing_loop is not self:
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raise RuntimeError(
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f"IOLoop {existing_loop} already associated with asyncio loop {asyncio_loop}"
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)
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super().initialize(**kwargs)
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def close(self, all_fds: bool = False) -> None:
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self.closing = True
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for fd in list(self.handlers):
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fileobj, handler_func = self.handlers[fd]
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self.remove_handler(fd)
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if all_fds:
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self.close_fd(fileobj)
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# Remove the mapping before closing the asyncio loop. If this
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# happened in the other order, we could race against another
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# initialize() call which would see the closed asyncio loop,
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# assume it was closed from the asyncio side, and do this
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# cleanup for us, leading to a KeyError.
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del IOLoop._ioloop_for_asyncio[self.asyncio_loop]
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if self.selector_loop is not self.asyncio_loop:
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self.selector_loop.close()
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self.asyncio_loop.close()
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def add_handler(
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self, fd: Union[int, _Selectable], handler: Callable[..., None], events: int
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) -> None:
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fd, fileobj = self.split_fd(fd)
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if fd in self.handlers:
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raise ValueError("fd %s added twice" % fd)
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self.handlers[fd] = (fileobj, handler)
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if events & IOLoop.READ:
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self.selector_loop.add_reader(fd, self._handle_events, fd, IOLoop.READ)
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self.readers.add(fd)
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if events & IOLoop.WRITE:
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self.selector_loop.add_writer(fd, self._handle_events, fd, IOLoop.WRITE)
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self.writers.add(fd)
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def update_handler(self, fd: Union[int, _Selectable], events: int) -> None:
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fd, fileobj = self.split_fd(fd)
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if events & IOLoop.READ:
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if fd not in self.readers:
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self.selector_loop.add_reader(fd, self._handle_events, fd, IOLoop.READ)
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self.readers.add(fd)
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else:
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if fd in self.readers:
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self.selector_loop.remove_reader(fd)
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self.readers.remove(fd)
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if events & IOLoop.WRITE:
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if fd not in self.writers:
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self.selector_loop.add_writer(fd, self._handle_events, fd, IOLoop.WRITE)
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self.writers.add(fd)
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else:
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if fd in self.writers:
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self.selector_loop.remove_writer(fd)
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self.writers.remove(fd)
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def remove_handler(self, fd: Union[int, _Selectable]) -> None:
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fd, fileobj = self.split_fd(fd)
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if fd not in self.handlers:
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return
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if fd in self.readers:
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self.selector_loop.remove_reader(fd)
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self.readers.remove(fd)
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if fd in self.writers:
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self.selector_loop.remove_writer(fd)
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self.writers.remove(fd)
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del self.handlers[fd]
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def _handle_events(self, fd: int, events: int) -> None:
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fileobj, handler_func = self.handlers[fd]
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handler_func(fileobj, events)
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def start(self) -> None:
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try:
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old_loop = _get_event_loop()
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except (RuntimeError, AssertionError):
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old_loop = None # type: ignore
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try:
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asyncio.set_event_loop(self.asyncio_loop)
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self.asyncio_loop.run_forever()
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finally:
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asyncio.set_event_loop(old_loop)
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def stop(self) -> None:
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self.asyncio_loop.stop()
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def call_at(
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self, when: float, callback: Callable, *args: Any, **kwargs: Any
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) -> object:
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# asyncio.call_at supports *args but not **kwargs, so bind them here.
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# We do not synchronize self.time and asyncio_loop.time, so
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# convert from absolute to relative.
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return self.asyncio_loop.call_later(
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max(0, when - self.time()),
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self._run_callback,
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functools.partial(callback, *args, **kwargs),
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)
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def remove_timeout(self, timeout: object) -> None:
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timeout.cancel() # type: ignore
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def add_callback(self, callback: Callable, *args: Any, **kwargs: Any) -> None:
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try:
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if asyncio.get_running_loop() is self.asyncio_loop:
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call_soon = self.asyncio_loop.call_soon
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else:
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call_soon = self.asyncio_loop.call_soon_threadsafe
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except RuntimeError:
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call_soon = self.asyncio_loop.call_soon_threadsafe
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try:
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call_soon(self._run_callback, functools.partial(callback, *args, **kwargs))
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except RuntimeError:
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# "Event loop is closed". Swallow the exception for
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# consistency with PollIOLoop (and logical consistency
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# with the fact that we can't guarantee that an
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# add_callback that completes without error will
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# eventually execute).
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pass
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except AttributeError:
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# ProactorEventLoop may raise this instead of RuntimeError
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# if call_soon_threadsafe races with a call to close().
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# Swallow it too for consistency.
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pass
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def add_callback_from_signal(
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self, callback: Callable, *args: Any, **kwargs: Any
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) -> None:
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try:
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self.asyncio_loop.call_soon_threadsafe(
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self._run_callback, functools.partial(callback, *args, **kwargs)
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)
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except RuntimeError:
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pass
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def run_in_executor(
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self,
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executor: Optional[concurrent.futures.Executor],
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func: Callable[..., _T],
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*args: Any,
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) -> Awaitable[_T]:
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return self.asyncio_loop.run_in_executor(executor, func, *args)
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def set_default_executor(self, executor: concurrent.futures.Executor) -> None:
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return self.asyncio_loop.set_default_executor(executor)
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class AsyncIOMainLoop(BaseAsyncIOLoop):
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"""``AsyncIOMainLoop`` creates an `.IOLoop` that corresponds to the
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current ``asyncio`` event loop (i.e. the one returned by
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``asyncio.get_event_loop()``).
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.. deprecated:: 5.0
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Now used automatically when appropriate; it is no longer necessary
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to refer to this class directly.
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.. versionchanged:: 5.0
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Closing an `AsyncIOMainLoop` now closes the underlying asyncio loop.
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"""
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def initialize(self, **kwargs: Any) -> None: # type: ignore
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super().initialize(asyncio.get_event_loop(), **kwargs)
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def make_current(self) -> None:
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# AsyncIOMainLoop already refers to the current asyncio loop so
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# nothing to do here.
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pass
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class AsyncIOLoop(BaseAsyncIOLoop):
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"""``AsyncIOLoop`` is an `.IOLoop` that runs on an ``asyncio`` event loop.
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This class follows the usual Tornado semantics for creating new
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``IOLoops``; these loops are not necessarily related to the
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``asyncio`` default event loop.
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Each ``AsyncIOLoop`` creates a new ``asyncio.EventLoop``; this object
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can be accessed with the ``asyncio_loop`` attribute.
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.. versionchanged:: 6.2
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Support explicit ``asyncio_loop`` argument
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for specifying the asyncio loop to attach to,
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rather than always creating a new one with the default policy.
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.. versionchanged:: 5.0
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When an ``AsyncIOLoop`` becomes the current `.IOLoop`, it also sets
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the current `asyncio` event loop.
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.. deprecated:: 5.0
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Now used automatically when appropriate; it is no longer necessary
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to refer to this class directly.
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"""
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def initialize(self, **kwargs: Any) -> None: # type: ignore
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self.is_current = False
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loop = None
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if "asyncio_loop" not in kwargs:
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kwargs["asyncio_loop"] = loop = asyncio.new_event_loop()
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try:
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super().initialize(**kwargs)
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except Exception:
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# If initialize() does not succeed (taking ownership of the loop),
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# we have to close it.
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if loop is not None:
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loop.close()
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raise
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def close(self, all_fds: bool = False) -> None:
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if self.is_current:
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self._clear_current()
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super().close(all_fds=all_fds)
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def make_current(self) -> None:
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warnings.warn(
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"make_current is deprecated; start the event loop first",
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DeprecationWarning,
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stacklevel=2,
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)
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if not self.is_current:
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try:
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self.old_asyncio = asyncio.get_event_loop()
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except (RuntimeError, AssertionError):
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self.old_asyncio = None # type: ignore
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self.is_current = True
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asyncio.set_event_loop(self.asyncio_loop)
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def _clear_current_hook(self) -> None:
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if self.is_current:
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asyncio.set_event_loop(self.old_asyncio)
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self.is_current = False
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def to_tornado_future(asyncio_future: asyncio.Future) -> asyncio.Future:
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"""Convert an `asyncio.Future` to a `tornado.concurrent.Future`.
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.. versionadded:: 4.1
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.. deprecated:: 5.0
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Tornado ``Futures`` have been merged with `asyncio.Future`,
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so this method is now a no-op.
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"""
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return asyncio_future
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def to_asyncio_future(tornado_future: asyncio.Future) -> asyncio.Future:
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"""Convert a Tornado yieldable object to an `asyncio.Future`.
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.. versionadded:: 4.1
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.. versionchanged:: 4.3
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Now accepts any yieldable object, not just
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`tornado.concurrent.Future`.
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.. deprecated:: 5.0
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Tornado ``Futures`` have been merged with `asyncio.Future`,
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so this method is now equivalent to `tornado.gen.convert_yielded`.
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"""
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return convert_yielded(tornado_future)
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if sys.platform == "win32" and hasattr(asyncio, "WindowsSelectorEventLoopPolicy"):
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# "Any thread" and "selector" should be orthogonal, but there's not a clean
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# interface for composing policies so pick the right base.
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_BasePolicy = asyncio.WindowsSelectorEventLoopPolicy # type: ignore
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else:
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_BasePolicy = asyncio.DefaultEventLoopPolicy
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class AnyThreadEventLoopPolicy(_BasePolicy): # type: ignore
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"""Event loop policy that allows loop creation on any thread.
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The default `asyncio` event loop policy only automatically creates
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event loops in the main threads. Other threads must create event
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loops explicitly or `asyncio.get_event_loop` (and therefore
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`.IOLoop.current`) will fail. Installing this policy allows event
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loops to be created automatically on any thread, matching the
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behavior of Tornado versions prior to 5.0 (or 5.0 on Python 2).
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Usage::
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asyncio.set_event_loop_policy(AnyThreadEventLoopPolicy())
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.. versionadded:: 5.0
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.. deprecated:: 6.2
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``AnyThreadEventLoopPolicy`` affects the implicit creation
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of an event loop, which is deprecated in Python 3.10 and
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will be removed in a future version of Python. At that time
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``AnyThreadEventLoopPolicy`` will no longer be useful.
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If you are relying on it, use `asyncio.new_event_loop`
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or `asyncio.run` explicitly in any non-main threads that
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need event loops.
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"""
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def __init__(self) -> None:
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super().__init__()
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warnings.warn(
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"AnyThreadEventLoopPolicy is deprecated, use asyncio.run "
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"or asyncio.new_event_loop instead",
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DeprecationWarning,
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stacklevel=2,
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)
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def get_event_loop(self) -> asyncio.AbstractEventLoop:
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try:
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return super().get_event_loop()
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except (RuntimeError, AssertionError):
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# This was an AssertionError in Python 3.4.2 (which ships with Debian Jessie)
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# and changed to a RuntimeError in 3.4.3.
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# "There is no current event loop in thread %r"
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loop = self.new_event_loop()
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self.set_event_loop(loop)
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return loop
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class AddThreadSelectorEventLoop(asyncio.AbstractEventLoop):
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"""Wrap an event loop to add implementations of the ``add_reader`` method family.
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Instances of this class start a second thread to run a selector.
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This thread is completely hidden from the user; all callbacks are
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run on the wrapped event loop's thread.
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This class is used automatically by Tornado; applications should not need
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to refer to it directly.
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It is safe to wrap any event loop with this class, although it only makes sense
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for event loops that do not implement the ``add_reader`` family of methods
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themselves (i.e. ``WindowsProactorEventLoop``)
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Closing the ``AddThreadSelectorEventLoop`` also closes the wrapped event loop.
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"""
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# This class is a __getattribute__-based proxy. All attributes other than those
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# in this set are proxied through to the underlying loop.
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MY_ATTRIBUTES = {
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"_consume_waker",
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"_select_cond",
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"_select_args",
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"_closing_selector",
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"_thread",
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"_handle_event",
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"_readers",
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"_real_loop",
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"_start_select",
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"_run_select",
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"_handle_select",
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"_wake_selector",
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"_waker_r",
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"_waker_w",
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"_writers",
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"add_reader",
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"add_writer",
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"close",
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"remove_reader",
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"remove_writer",
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}
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def __getattribute__(self, name: str) -> Any:
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if name in AddThreadSelectorEventLoop.MY_ATTRIBUTES:
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return super().__getattribute__(name)
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return getattr(self._real_loop, name)
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def __init__(self, real_loop: asyncio.AbstractEventLoop) -> None:
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|
self._real_loop = real_loop
|
|
|
|
# Create a thread to run the select system call. We manage this thread
|
|
# manually so we can trigger a clean shutdown from an atexit hook. Note
|
|
# that due to the order of operations at shutdown, only daemon threads
|
|
# can be shut down in this way (non-daemon threads would require the
|
|
# introduction of a new hook: https://bugs.python.org/issue41962)
|
|
self._select_cond = threading.Condition()
|
|
self._select_args = (
|
|
None
|
|
) # type: Optional[Tuple[List[_FileDescriptorLike], List[_FileDescriptorLike]]]
|
|
self._closing_selector = False
|
|
self._thread = threading.Thread(
|
|
name="Tornado selector",
|
|
daemon=True,
|
|
target=self._run_select,
|
|
)
|
|
self._thread.start()
|
|
# Start the select loop once the loop is started.
|
|
self._real_loop.call_soon(self._start_select)
|
|
|
|
self._readers = {} # type: Dict[_FileDescriptorLike, Callable]
|
|
self._writers = {} # type: Dict[_FileDescriptorLike, Callable]
|
|
|
|
# Writing to _waker_w will wake up the selector thread, which
|
|
# watches for _waker_r to be readable.
|
|
self._waker_r, self._waker_w = socket.socketpair()
|
|
self._waker_r.setblocking(False)
|
|
self._waker_w.setblocking(False)
|
|
_selector_loops.add(self)
|
|
self.add_reader(self._waker_r, self._consume_waker)
|
|
|
|
def __del__(self) -> None:
|
|
# If the top-level application code uses asyncio interfaces to
|
|
# start and stop the event loop, no objects created in Tornado
|
|
# can get a clean shutdown notification. If we're just left to
|
|
# be GC'd, we must explicitly close our sockets to avoid
|
|
# logging warnings.
|
|
_selector_loops.discard(self)
|
|
self._waker_r.close()
|
|
self._waker_w.close()
|
|
|
|
def close(self) -> None:
|
|
with self._select_cond:
|
|
self._closing_selector = True
|
|
self._select_cond.notify()
|
|
self._wake_selector()
|
|
self._thread.join()
|
|
_selector_loops.discard(self)
|
|
self._waker_r.close()
|
|
self._waker_w.close()
|
|
self._real_loop.close()
|
|
|
|
def _wake_selector(self) -> None:
|
|
try:
|
|
self._waker_w.send(b"a")
|
|
except BlockingIOError:
|
|
pass
|
|
|
|
def _consume_waker(self) -> None:
|
|
try:
|
|
self._waker_r.recv(1024)
|
|
except BlockingIOError:
|
|
pass
|
|
|
|
def _start_select(self) -> None:
|
|
# Capture reader and writer sets here in the event loop
|
|
# thread to avoid any problems with concurrent
|
|
# modification while the select loop uses them.
|
|
with self._select_cond:
|
|
assert self._select_args is None
|
|
self._select_args = (list(self._readers.keys()), list(self._writers.keys()))
|
|
self._select_cond.notify()
|
|
|
|
def _run_select(self) -> None:
|
|
while True:
|
|
with self._select_cond:
|
|
while self._select_args is None and not self._closing_selector:
|
|
self._select_cond.wait()
|
|
if self._closing_selector:
|
|
return
|
|
assert self._select_args is not None
|
|
to_read, to_write = self._select_args
|
|
self._select_args = None
|
|
|
|
# We use the simpler interface of the select module instead of
|
|
# the more stateful interface in the selectors module because
|
|
# this class is only intended for use on windows, where
|
|
# select.select is the only option. The selector interface
|
|
# does not have well-documented thread-safety semantics that
|
|
# we can rely on so ensuring proper synchronization would be
|
|
# tricky.
|
|
try:
|
|
# On windows, selecting on a socket for write will not
|
|
# return the socket when there is an error (but selecting
|
|
# for reads works). Also select for errors when selecting
|
|
# for writes, and merge the results.
|
|
#
|
|
# This pattern is also used in
|
|
# https://github.com/python/cpython/blob/v3.8.0/Lib/selectors.py#L312-L317
|
|
rs, ws, xs = select.select(to_read, to_write, to_write)
|
|
ws = ws + xs
|
|
except OSError as e:
|
|
# After remove_reader or remove_writer is called, the file
|
|
# descriptor may subsequently be closed on the event loop
|
|
# thread. It's possible that this select thread hasn't
|
|
# gotten into the select system call by the time that
|
|
# happens in which case (at least on macOS), select may
|
|
# raise a "bad file descriptor" error. If we get that
|
|
# error, check and see if we're also being woken up by
|
|
# polling the waker alone. If we are, just return to the
|
|
# event loop and we'll get the updated set of file
|
|
# descriptors on the next iteration. Otherwise, raise the
|
|
# original error.
|
|
if e.errno == getattr(errno, "WSAENOTSOCK", errno.EBADF):
|
|
rs, _, _ = select.select([self._waker_r.fileno()], [], [], 0)
|
|
if rs:
|
|
ws = []
|
|
else:
|
|
raise
|
|
else:
|
|
raise
|
|
|
|
try:
|
|
self._real_loop.call_soon_threadsafe(self._handle_select, rs, ws)
|
|
except RuntimeError:
|
|
# "Event loop is closed". Swallow the exception for
|
|
# consistency with PollIOLoop (and logical consistency
|
|
# with the fact that we can't guarantee that an
|
|
# add_callback that completes without error will
|
|
# eventually execute).
|
|
pass
|
|
except AttributeError:
|
|
# ProactorEventLoop may raise this instead of RuntimeError
|
|
# if call_soon_threadsafe races with a call to close().
|
|
# Swallow it too for consistency.
|
|
pass
|
|
|
|
def _handle_select(
|
|
self, rs: List["_FileDescriptorLike"], ws: List["_FileDescriptorLike"]
|
|
) -> None:
|
|
for r in rs:
|
|
self._handle_event(r, self._readers)
|
|
for w in ws:
|
|
self._handle_event(w, self._writers)
|
|
self._start_select()
|
|
|
|
def _handle_event(
|
|
self,
|
|
fd: "_FileDescriptorLike",
|
|
cb_map: Dict["_FileDescriptorLike", Callable],
|
|
) -> None:
|
|
try:
|
|
callback = cb_map[fd]
|
|
except KeyError:
|
|
return
|
|
callback()
|
|
|
|
def add_reader(
|
|
self, fd: "_FileDescriptorLike", callback: Callable[..., None], *args: Any
|
|
) -> None:
|
|
self._readers[fd] = functools.partial(callback, *args)
|
|
self._wake_selector()
|
|
|
|
def add_writer(
|
|
self, fd: "_FileDescriptorLike", callback: Callable[..., None], *args: Any
|
|
) -> None:
|
|
self._writers[fd] = functools.partial(callback, *args)
|
|
self._wake_selector()
|
|
|
|
def remove_reader(self, fd: "_FileDescriptorLike") -> None:
|
|
del self._readers[fd]
|
|
self._wake_selector()
|
|
|
|
def remove_writer(self, fd: "_FileDescriptorLike") -> None:
|
|
del self._writers[fd]
|
|
self._wake_selector()
|