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author | cyfraeviolae <cyfraeviolae> | 2024-04-03 03:10:44 -0400 |
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committer | cyfraeviolae <cyfraeviolae> | 2024-04-03 03:10:44 -0400 |
commit | 6d7ba58f880be618ade07f8ea080fe8c4bf8a896 (patch) | |
tree | b1c931051ffcebd2bd9d61d98d6233ffa289bbce /venv/lib/python3.11/site-packages/anyio/from_thread.py | |
parent | 4f884c9abc32990b4061a1bb6997b4b37e58ea0b (diff) |
venv
Diffstat (limited to 'venv/lib/python3.11/site-packages/anyio/from_thread.py')
-rw-r--r-- | venv/lib/python3.11/site-packages/anyio/from_thread.py | 476 |
1 files changed, 476 insertions, 0 deletions
diff --git a/venv/lib/python3.11/site-packages/anyio/from_thread.py b/venv/lib/python3.11/site-packages/anyio/from_thread.py new file mode 100644 index 0000000..4a98703 --- /dev/null +++ b/venv/lib/python3.11/site-packages/anyio/from_thread.py @@ -0,0 +1,476 @@ +from __future__ import annotations + +import sys +import threading +from collections.abc import Awaitable, Callable, Generator +from concurrent.futures import FIRST_COMPLETED, Future, ThreadPoolExecutor, wait +from contextlib import AbstractContextManager, contextmanager +from inspect import isawaitable +from types import TracebackType +from typing import ( + Any, + AsyncContextManager, + ContextManager, + Generic, + Iterable, + TypeVar, + cast, + overload, +) + +from ._core import _eventloop +from ._core._eventloop import get_async_backend, get_cancelled_exc_class, threadlocals +from ._core._synchronization import Event +from ._core._tasks import CancelScope, create_task_group +from .abc import AsyncBackend +from .abc._tasks import TaskStatus + +if sys.version_info >= (3, 11): + from typing import TypeVarTuple, Unpack +else: + from typing_extensions import TypeVarTuple, Unpack + +T_Retval = TypeVar("T_Retval") +T_co = TypeVar("T_co", covariant=True) +PosArgsT = TypeVarTuple("PosArgsT") + + +def run( + func: Callable[[Unpack[PosArgsT]], Awaitable[T_Retval]], *args: Unpack[PosArgsT] +) -> T_Retval: + """ + Call a coroutine function from a worker thread. + + :param func: a coroutine function + :param args: positional arguments for the callable + :return: the return value of the coroutine function + + """ + try: + async_backend = threadlocals.current_async_backend + token = threadlocals.current_token + except AttributeError: + raise RuntimeError( + "This function can only be run from an AnyIO worker thread" + ) from None + + return async_backend.run_async_from_thread(func, args, token=token) + + +def run_sync( + func: Callable[[Unpack[PosArgsT]], T_Retval], *args: Unpack[PosArgsT] +) -> T_Retval: + """ + Call a function in the event loop thread from a worker thread. + + :param func: a callable + :param args: positional arguments for the callable + :return: the return value of the callable + + """ + try: + async_backend = threadlocals.current_async_backend + token = threadlocals.current_token + except AttributeError: + raise RuntimeError( + "This function can only be run from an AnyIO worker thread" + ) from None + + return async_backend.run_sync_from_thread(func, args, token=token) + + +class _BlockingAsyncContextManager(Generic[T_co], AbstractContextManager): + _enter_future: Future[T_co] + _exit_future: Future[bool | None] + _exit_event: Event + _exit_exc_info: tuple[ + type[BaseException] | None, BaseException | None, TracebackType | None + ] = (None, None, None) + + def __init__(self, async_cm: AsyncContextManager[T_co], portal: BlockingPortal): + self._async_cm = async_cm + self._portal = portal + + async def run_async_cm(self) -> bool | None: + try: + self._exit_event = Event() + value = await self._async_cm.__aenter__() + except BaseException as exc: + self._enter_future.set_exception(exc) + raise + else: + self._enter_future.set_result(value) + + try: + # Wait for the sync context manager to exit. + # This next statement can raise `get_cancelled_exc_class()` if + # something went wrong in a task group in this async context + # manager. + await self._exit_event.wait() + finally: + # In case of cancellation, it could be that we end up here before + # `_BlockingAsyncContextManager.__exit__` is called, and an + # `_exit_exc_info` has been set. + result = await self._async_cm.__aexit__(*self._exit_exc_info) + return result + + def __enter__(self) -> T_co: + self._enter_future = Future() + self._exit_future = self._portal.start_task_soon(self.run_async_cm) + return self._enter_future.result() + + def __exit__( + self, + __exc_type: type[BaseException] | None, + __exc_value: BaseException | None, + __traceback: TracebackType | None, + ) -> bool | None: + self._exit_exc_info = __exc_type, __exc_value, __traceback + self._portal.call(self._exit_event.set) + return self._exit_future.result() + + +class _BlockingPortalTaskStatus(TaskStatus): + def __init__(self, future: Future): + self._future = future + + def started(self, value: object = None) -> None: + self._future.set_result(value) + + +class BlockingPortal: + """An object that lets external threads run code in an asynchronous event loop.""" + + def __new__(cls) -> BlockingPortal: + return get_async_backend().create_blocking_portal() + + def __init__(self) -> None: + self._event_loop_thread_id: int | None = threading.get_ident() + self._stop_event = Event() + self._task_group = create_task_group() + self._cancelled_exc_class = get_cancelled_exc_class() + + async def __aenter__(self) -> BlockingPortal: + await self._task_group.__aenter__() + return self + + async def __aexit__( + self, + exc_type: type[BaseException] | None, + exc_val: BaseException | None, + exc_tb: TracebackType | None, + ) -> bool | None: + await self.stop() + return await self._task_group.__aexit__(exc_type, exc_val, exc_tb) + + def _check_running(self) -> None: + if self._event_loop_thread_id is None: + raise RuntimeError("This portal is not running") + if self._event_loop_thread_id == threading.get_ident(): + raise RuntimeError( + "This method cannot be called from the event loop thread" + ) + + async def sleep_until_stopped(self) -> None: + """Sleep until :meth:`stop` is called.""" + await self._stop_event.wait() + + async def stop(self, cancel_remaining: bool = False) -> None: + """ + Signal the portal to shut down. + + This marks the portal as no longer accepting new calls and exits from + :meth:`sleep_until_stopped`. + + :param cancel_remaining: ``True`` to cancel all the remaining tasks, ``False`` + to let them finish before returning + + """ + self._event_loop_thread_id = None + self._stop_event.set() + if cancel_remaining: + self._task_group.cancel_scope.cancel() + + async def _call_func( + self, + func: Callable[[Unpack[PosArgsT]], Awaitable[T_Retval] | T_Retval], + args: tuple[Unpack[PosArgsT]], + kwargs: dict[str, Any], + future: Future[T_Retval], + ) -> None: + def callback(f: Future[T_Retval]) -> None: + if f.cancelled() and self._event_loop_thread_id not in ( + None, + threading.get_ident(), + ): + self.call(scope.cancel) + + try: + retval_or_awaitable = func(*args, **kwargs) + if isawaitable(retval_or_awaitable): + with CancelScope() as scope: + if future.cancelled(): + scope.cancel() + else: + future.add_done_callback(callback) + + retval = await retval_or_awaitable + else: + retval = retval_or_awaitable + except self._cancelled_exc_class: + future.cancel() + future.set_running_or_notify_cancel() + except BaseException as exc: + if not future.cancelled(): + future.set_exception(exc) + + # Let base exceptions fall through + if not isinstance(exc, Exception): + raise + else: + if not future.cancelled(): + future.set_result(retval) + finally: + scope = None # type: ignore[assignment] + + def _spawn_task_from_thread( + self, + func: Callable[[Unpack[PosArgsT]], Awaitable[T_Retval] | T_Retval], + args: tuple[Unpack[PosArgsT]], + kwargs: dict[str, Any], + name: object, + future: Future[T_Retval], + ) -> None: + """ + Spawn a new task using the given callable. + + Implementors must ensure that the future is resolved when the task finishes. + + :param func: a callable + :param args: positional arguments to be passed to the callable + :param kwargs: keyword arguments to be passed to the callable + :param name: name of the task (will be coerced to a string if not ``None``) + :param future: a future that will resolve to the return value of the callable, + or the exception raised during its execution + + """ + raise NotImplementedError + + @overload + def call( + self, + func: Callable[[Unpack[PosArgsT]], Awaitable[T_Retval]], + *args: Unpack[PosArgsT], + ) -> T_Retval: + ... + + @overload + def call( + self, func: Callable[[Unpack[PosArgsT]], T_Retval], *args: Unpack[PosArgsT] + ) -> T_Retval: + ... + + def call( + self, + func: Callable[[Unpack[PosArgsT]], Awaitable[T_Retval] | T_Retval], + *args: Unpack[PosArgsT], + ) -> T_Retval: + """ + Call the given function in the event loop thread. + + If the callable returns a coroutine object, it is awaited on. + + :param func: any callable + :raises RuntimeError: if the portal is not running or if this method is called + from within the event loop thread + + """ + return cast(T_Retval, self.start_task_soon(func, *args).result()) + + @overload + def start_task_soon( + self, + func: Callable[[Unpack[PosArgsT]], Awaitable[T_Retval]], + *args: Unpack[PosArgsT], + name: object = None, + ) -> Future[T_Retval]: + ... + + @overload + def start_task_soon( + self, + func: Callable[[Unpack[PosArgsT]], T_Retval], + *args: Unpack[PosArgsT], + name: object = None, + ) -> Future[T_Retval]: + ... + + def start_task_soon( + self, + func: Callable[[Unpack[PosArgsT]], Awaitable[T_Retval] | T_Retval], + *args: Unpack[PosArgsT], + name: object = None, + ) -> Future[T_Retval]: + """ + Start a task in the portal's task group. + + The task will be run inside a cancel scope which can be cancelled by cancelling + the returned future. + + :param func: the target function + :param args: positional arguments passed to ``func`` + :param name: name of the task (will be coerced to a string if not ``None``) + :return: a future that resolves with the return value of the callable if the + task completes successfully, or with the exception raised in the task + :raises RuntimeError: if the portal is not running or if this method is called + from within the event loop thread + :rtype: concurrent.futures.Future[T_Retval] + + .. versionadded:: 3.0 + + """ + self._check_running() + f: Future[T_Retval] = Future() + self._spawn_task_from_thread(func, args, {}, name, f) + return f + + def start_task( + self, + func: Callable[..., Awaitable[T_Retval]], + *args: object, + name: object = None, + ) -> tuple[Future[T_Retval], Any]: + """ + Start a task in the portal's task group and wait until it signals for readiness. + + This method works the same way as :meth:`.abc.TaskGroup.start`. + + :param func: the target function + :param args: positional arguments passed to ``func`` + :param name: name of the task (will be coerced to a string if not ``None``) + :return: a tuple of (future, task_status_value) where the ``task_status_value`` + is the value passed to ``task_status.started()`` from within the target + function + :rtype: tuple[concurrent.futures.Future[T_Retval], Any] + + .. versionadded:: 3.0 + + """ + + def task_done(future: Future[T_Retval]) -> None: + if not task_status_future.done(): + if future.cancelled(): + task_status_future.cancel() + elif future.exception(): + task_status_future.set_exception(future.exception()) + else: + exc = RuntimeError( + "Task exited without calling task_status.started()" + ) + task_status_future.set_exception(exc) + + self._check_running() + task_status_future: Future = Future() + task_status = _BlockingPortalTaskStatus(task_status_future) + f: Future = Future() + f.add_done_callback(task_done) + self._spawn_task_from_thread(func, args, {"task_status": task_status}, name, f) + return f, task_status_future.result() + + def wrap_async_context_manager( + self, cm: AsyncContextManager[T_co] + ) -> ContextManager[T_co]: + """ + Wrap an async context manager as a synchronous context manager via this portal. + + Spawns a task that will call both ``__aenter__()`` and ``__aexit__()``, stopping + in the middle until the synchronous context manager exits. + + :param cm: an asynchronous context manager + :return: a synchronous context manager + + .. versionadded:: 2.1 + + """ + return _BlockingAsyncContextManager(cm, self) + + +@contextmanager +def start_blocking_portal( + backend: str = "asyncio", backend_options: dict[str, Any] | None = None +) -> Generator[BlockingPortal, Any, None]: + """ + Start a new event loop in a new thread and run a blocking portal in its main task. + + The parameters are the same as for :func:`~anyio.run`. + + :param backend: name of the backend + :param backend_options: backend options + :return: a context manager that yields a blocking portal + + .. versionchanged:: 3.0 + Usage as a context manager is now required. + + """ + + async def run_portal() -> None: + async with BlockingPortal() as portal_: + if future.set_running_or_notify_cancel(): + future.set_result(portal_) + await portal_.sleep_until_stopped() + + future: Future[BlockingPortal] = Future() + with ThreadPoolExecutor(1) as executor: + run_future = executor.submit( + _eventloop.run, # type: ignore[arg-type] + run_portal, + backend=backend, + backend_options=backend_options, + ) + try: + wait( + cast(Iterable[Future], [run_future, future]), + return_when=FIRST_COMPLETED, + ) + except BaseException: + future.cancel() + run_future.cancel() + raise + + if future.done(): + portal = future.result() + cancel_remaining_tasks = False + try: + yield portal + except BaseException: + cancel_remaining_tasks = True + raise + finally: + try: + portal.call(portal.stop, cancel_remaining_tasks) + except RuntimeError: + pass + + run_future.result() + + +def check_cancelled() -> None: + """ + Check if the cancel scope of the host task's running the current worker thread has + been cancelled. + + If the host task's current cancel scope has indeed been cancelled, the + backend-specific cancellation exception will be raised. + + :raises RuntimeError: if the current thread was not spawned by + :func:`.to_thread.run_sync` + + """ + try: + async_backend: AsyncBackend = threadlocals.current_async_backend + except AttributeError: + raise RuntimeError( + "This function can only be run from an AnyIO worker thread" + ) from None + + async_backend.check_cancelled() |