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Diffstat (limited to '.venv/lib/python3.12/site-packages/anyio/_core/_synchronization.py')
-rw-r--r-- | .venv/lib/python3.12/site-packages/anyio/_core/_synchronization.py | 732 |
1 files changed, 732 insertions, 0 deletions
diff --git a/.venv/lib/python3.12/site-packages/anyio/_core/_synchronization.py b/.venv/lib/python3.12/site-packages/anyio/_core/_synchronization.py new file mode 100644 index 00000000..a6331328 --- /dev/null +++ b/.venv/lib/python3.12/site-packages/anyio/_core/_synchronization.py @@ -0,0 +1,732 @@ +from __future__ import annotations + +import math +from collections import deque +from dataclasses import dataclass +from types import TracebackType + +from sniffio import AsyncLibraryNotFoundError + +from ..lowlevel import checkpoint +from ._eventloop import get_async_backend +from ._exceptions import BusyResourceError +from ._tasks import CancelScope +from ._testing import TaskInfo, get_current_task + + +@dataclass(frozen=True) +class EventStatistics: + """ + :ivar int tasks_waiting: number of tasks waiting on :meth:`~.Event.wait` + """ + + tasks_waiting: int + + +@dataclass(frozen=True) +class CapacityLimiterStatistics: + """ + :ivar int borrowed_tokens: number of tokens currently borrowed by tasks + :ivar float total_tokens: total number of available tokens + :ivar tuple borrowers: tasks or other objects currently holding tokens borrowed from + this limiter + :ivar int tasks_waiting: number of tasks waiting on + :meth:`~.CapacityLimiter.acquire` or + :meth:`~.CapacityLimiter.acquire_on_behalf_of` + """ + + borrowed_tokens: int + total_tokens: float + borrowers: tuple[object, ...] + tasks_waiting: int + + +@dataclass(frozen=True) +class LockStatistics: + """ + :ivar bool locked: flag indicating if this lock is locked or not + :ivar ~anyio.TaskInfo owner: task currently holding the lock (or ``None`` if the + lock is not held by any task) + :ivar int tasks_waiting: number of tasks waiting on :meth:`~.Lock.acquire` + """ + + locked: bool + owner: TaskInfo | None + tasks_waiting: int + + +@dataclass(frozen=True) +class ConditionStatistics: + """ + :ivar int tasks_waiting: number of tasks blocked on :meth:`~.Condition.wait` + :ivar ~anyio.LockStatistics lock_statistics: statistics of the underlying + :class:`~.Lock` + """ + + tasks_waiting: int + lock_statistics: LockStatistics + + +@dataclass(frozen=True) +class SemaphoreStatistics: + """ + :ivar int tasks_waiting: number of tasks waiting on :meth:`~.Semaphore.acquire` + + """ + + tasks_waiting: int + + +class Event: + def __new__(cls) -> Event: + try: + return get_async_backend().create_event() + except AsyncLibraryNotFoundError: + return EventAdapter() + + def set(self) -> None: + """Set the flag, notifying all listeners.""" + raise NotImplementedError + + def is_set(self) -> bool: + """Return ``True`` if the flag is set, ``False`` if not.""" + raise NotImplementedError + + async def wait(self) -> None: + """ + Wait until the flag has been set. + + If the flag has already been set when this method is called, it returns + immediately. + + """ + raise NotImplementedError + + def statistics(self) -> EventStatistics: + """Return statistics about the current state of this event.""" + raise NotImplementedError + + +class EventAdapter(Event): + _internal_event: Event | None = None + _is_set: bool = False + + def __new__(cls) -> EventAdapter: + return object.__new__(cls) + + @property + def _event(self) -> Event: + if self._internal_event is None: + self._internal_event = get_async_backend().create_event() + if self._is_set: + self._internal_event.set() + + return self._internal_event + + def set(self) -> None: + if self._internal_event is None: + self._is_set = True + else: + self._event.set() + + def is_set(self) -> bool: + if self._internal_event is None: + return self._is_set + + return self._internal_event.is_set() + + async def wait(self) -> None: + await self._event.wait() + + def statistics(self) -> EventStatistics: + if self._internal_event is None: + return EventStatistics(tasks_waiting=0) + + return self._internal_event.statistics() + + +class Lock: + def __new__(cls, *, fast_acquire: bool = False) -> Lock: + try: + return get_async_backend().create_lock(fast_acquire=fast_acquire) + except AsyncLibraryNotFoundError: + return LockAdapter(fast_acquire=fast_acquire) + + async def __aenter__(self) -> None: + await self.acquire() + + async def __aexit__( + self, + exc_type: type[BaseException] | None, + exc_val: BaseException | None, + exc_tb: TracebackType | None, + ) -> None: + self.release() + + async def acquire(self) -> None: + """Acquire the lock.""" + raise NotImplementedError + + def acquire_nowait(self) -> None: + """ + Acquire the lock, without blocking. + + :raises ~anyio.WouldBlock: if the operation would block + + """ + raise NotImplementedError + + def release(self) -> None: + """Release the lock.""" + raise NotImplementedError + + def locked(self) -> bool: + """Return True if the lock is currently held.""" + raise NotImplementedError + + def statistics(self) -> LockStatistics: + """ + Return statistics about the current state of this lock. + + .. versionadded:: 3.0 + """ + raise NotImplementedError + + +class LockAdapter(Lock): + _internal_lock: Lock | None = None + + def __new__(cls, *, fast_acquire: bool = False) -> LockAdapter: + return object.__new__(cls) + + def __init__(self, *, fast_acquire: bool = False): + self._fast_acquire = fast_acquire + + @property + def _lock(self) -> Lock: + if self._internal_lock is None: + self._internal_lock = get_async_backend().create_lock( + fast_acquire=self._fast_acquire + ) + + return self._internal_lock + + async def __aenter__(self) -> None: + await self._lock.acquire() + + async def __aexit__( + self, + exc_type: type[BaseException] | None, + exc_val: BaseException | None, + exc_tb: TracebackType | None, + ) -> None: + if self._internal_lock is not None: + self._internal_lock.release() + + async def acquire(self) -> None: + """Acquire the lock.""" + await self._lock.acquire() + + def acquire_nowait(self) -> None: + """ + Acquire the lock, without blocking. + + :raises ~anyio.WouldBlock: if the operation would block + + """ + self._lock.acquire_nowait() + + def release(self) -> None: + """Release the lock.""" + self._lock.release() + + def locked(self) -> bool: + """Return True if the lock is currently held.""" + return self._lock.locked() + + def statistics(self) -> LockStatistics: + """ + Return statistics about the current state of this lock. + + .. versionadded:: 3.0 + + """ + if self._internal_lock is None: + return LockStatistics(False, None, 0) + + return self._internal_lock.statistics() + + +class Condition: + _owner_task: TaskInfo | None = None + + def __init__(self, lock: Lock | None = None): + self._lock = lock or Lock() + self._waiters: deque[Event] = deque() + + async def __aenter__(self) -> None: + await self.acquire() + + async def __aexit__( + self, + exc_type: type[BaseException] | None, + exc_val: BaseException | None, + exc_tb: TracebackType | None, + ) -> None: + self.release() + + def _check_acquired(self) -> None: + if self._owner_task != get_current_task(): + raise RuntimeError("The current task is not holding the underlying lock") + + async def acquire(self) -> None: + """Acquire the underlying lock.""" + await self._lock.acquire() + self._owner_task = get_current_task() + + def acquire_nowait(self) -> None: + """ + Acquire the underlying lock, without blocking. + + :raises ~anyio.WouldBlock: if the operation would block + + """ + self._lock.acquire_nowait() + self._owner_task = get_current_task() + + def release(self) -> None: + """Release the underlying lock.""" + self._lock.release() + + def locked(self) -> bool: + """Return True if the lock is set.""" + return self._lock.locked() + + def notify(self, n: int = 1) -> None: + """Notify exactly n listeners.""" + self._check_acquired() + for _ in range(n): + try: + event = self._waiters.popleft() + except IndexError: + break + + event.set() + + def notify_all(self) -> None: + """Notify all the listeners.""" + self._check_acquired() + for event in self._waiters: + event.set() + + self._waiters.clear() + + async def wait(self) -> None: + """Wait for a notification.""" + await checkpoint() + event = Event() + self._waiters.append(event) + self.release() + try: + await event.wait() + except BaseException: + if not event.is_set(): + self._waiters.remove(event) + + raise + finally: + with CancelScope(shield=True): + await self.acquire() + + def statistics(self) -> ConditionStatistics: + """ + Return statistics about the current state of this condition. + + .. versionadded:: 3.0 + """ + return ConditionStatistics(len(self._waiters), self._lock.statistics()) + + +class Semaphore: + def __new__( + cls, + initial_value: int, + *, + max_value: int | None = None, + fast_acquire: bool = False, + ) -> Semaphore: + try: + return get_async_backend().create_semaphore( + initial_value, max_value=max_value, fast_acquire=fast_acquire + ) + except AsyncLibraryNotFoundError: + return SemaphoreAdapter(initial_value, max_value=max_value) + + def __init__( + self, + initial_value: int, + *, + max_value: int | None = None, + fast_acquire: bool = False, + ): + if not isinstance(initial_value, int): + raise TypeError("initial_value must be an integer") + if initial_value < 0: + raise ValueError("initial_value must be >= 0") + if max_value is not None: + if not isinstance(max_value, int): + raise TypeError("max_value must be an integer or None") + if max_value < initial_value: + raise ValueError( + "max_value must be equal to or higher than initial_value" + ) + + self._fast_acquire = fast_acquire + + async def __aenter__(self) -> Semaphore: + await self.acquire() + return self + + async def __aexit__( + self, + exc_type: type[BaseException] | None, + exc_val: BaseException | None, + exc_tb: TracebackType | None, + ) -> None: + self.release() + + async def acquire(self) -> None: + """Decrement the semaphore value, blocking if necessary.""" + raise NotImplementedError + + def acquire_nowait(self) -> None: + """ + Acquire the underlying lock, without blocking. + + :raises ~anyio.WouldBlock: if the operation would block + + """ + raise NotImplementedError + + def release(self) -> None: + """Increment the semaphore value.""" + raise NotImplementedError + + @property + def value(self) -> int: + """The current value of the semaphore.""" + raise NotImplementedError + + @property + def max_value(self) -> int | None: + """The maximum value of the semaphore.""" + raise NotImplementedError + + def statistics(self) -> SemaphoreStatistics: + """ + Return statistics about the current state of this semaphore. + + .. versionadded:: 3.0 + """ + raise NotImplementedError + + +class SemaphoreAdapter(Semaphore): + _internal_semaphore: Semaphore | None = None + + def __new__( + cls, + initial_value: int, + *, + max_value: int | None = None, + fast_acquire: bool = False, + ) -> SemaphoreAdapter: + return object.__new__(cls) + + def __init__( + self, + initial_value: int, + *, + max_value: int | None = None, + fast_acquire: bool = False, + ) -> None: + super().__init__(initial_value, max_value=max_value, fast_acquire=fast_acquire) + self._initial_value = initial_value + self._max_value = max_value + + @property + def _semaphore(self) -> Semaphore: + if self._internal_semaphore is None: + self._internal_semaphore = get_async_backend().create_semaphore( + self._initial_value, max_value=self._max_value + ) + + return self._internal_semaphore + + async def acquire(self) -> None: + await self._semaphore.acquire() + + def acquire_nowait(self) -> None: + self._semaphore.acquire_nowait() + + def release(self) -> None: + self._semaphore.release() + + @property + def value(self) -> int: + if self._internal_semaphore is None: + return self._initial_value + + return self._semaphore.value + + @property + def max_value(self) -> int | None: + return self._max_value + + def statistics(self) -> SemaphoreStatistics: + if self._internal_semaphore is None: + return SemaphoreStatistics(tasks_waiting=0) + + return self._semaphore.statistics() + + +class CapacityLimiter: + def __new__(cls, total_tokens: float) -> CapacityLimiter: + try: + return get_async_backend().create_capacity_limiter(total_tokens) + except AsyncLibraryNotFoundError: + return CapacityLimiterAdapter(total_tokens) + + async def __aenter__(self) -> None: + raise NotImplementedError + + async def __aexit__( + self, + exc_type: type[BaseException] | None, + exc_val: BaseException | None, + exc_tb: TracebackType | None, + ) -> bool | None: + raise NotImplementedError + + @property + def total_tokens(self) -> float: + """ + The total number of tokens available for borrowing. + + This is a read-write property. If the total number of tokens is increased, the + proportionate number of tasks waiting on this limiter will be granted their + tokens. + + .. versionchanged:: 3.0 + The property is now writable. + + """ + raise NotImplementedError + + @total_tokens.setter + def total_tokens(self, value: float) -> None: + raise NotImplementedError + + @property + def borrowed_tokens(self) -> int: + """The number of tokens that have currently been borrowed.""" + raise NotImplementedError + + @property + def available_tokens(self) -> float: + """The number of tokens currently available to be borrowed""" + raise NotImplementedError + + def acquire_nowait(self) -> None: + """ + Acquire a token for the current task without waiting for one to become + available. + + :raises ~anyio.WouldBlock: if there are no tokens available for borrowing + + """ + raise NotImplementedError + + def acquire_on_behalf_of_nowait(self, borrower: object) -> None: + """ + Acquire a token without waiting for one to become available. + + :param borrower: the entity borrowing a token + :raises ~anyio.WouldBlock: if there are no tokens available for borrowing + + """ + raise NotImplementedError + + async def acquire(self) -> None: + """ + Acquire a token for the current task, waiting if necessary for one to become + available. + + """ + raise NotImplementedError + + async def acquire_on_behalf_of(self, borrower: object) -> None: + """ + Acquire a token, waiting if necessary for one to become available. + + :param borrower: the entity borrowing a token + + """ + raise NotImplementedError + + def release(self) -> None: + """ + Release the token held by the current task. + + :raises RuntimeError: if the current task has not borrowed a token from this + limiter. + + """ + raise NotImplementedError + + def release_on_behalf_of(self, borrower: object) -> None: + """ + Release the token held by the given borrower. + + :raises RuntimeError: if the borrower has not borrowed a token from this + limiter. + + """ + raise NotImplementedError + + def statistics(self) -> CapacityLimiterStatistics: + """ + Return statistics about the current state of this limiter. + + .. versionadded:: 3.0 + + """ + raise NotImplementedError + + +class CapacityLimiterAdapter(CapacityLimiter): + _internal_limiter: CapacityLimiter | None = None + + def __new__(cls, total_tokens: float) -> CapacityLimiterAdapter: + return object.__new__(cls) + + def __init__(self, total_tokens: float) -> None: + self.total_tokens = total_tokens + + @property + def _limiter(self) -> CapacityLimiter: + if self._internal_limiter is None: + self._internal_limiter = get_async_backend().create_capacity_limiter( + self._total_tokens + ) + + return self._internal_limiter + + async def __aenter__(self) -> None: + await self._limiter.__aenter__() + + async def __aexit__( + self, + exc_type: type[BaseException] | None, + exc_val: BaseException | None, + exc_tb: TracebackType | None, + ) -> bool | None: + return await self._limiter.__aexit__(exc_type, exc_val, exc_tb) + + @property + def total_tokens(self) -> float: + if self._internal_limiter is None: + return self._total_tokens + + return self._internal_limiter.total_tokens + + @total_tokens.setter + def total_tokens(self, value: float) -> None: + if not isinstance(value, int) and value is not math.inf: + raise TypeError("total_tokens must be an int or math.inf") + elif value < 1: + raise ValueError("total_tokens must be >= 1") + + if self._internal_limiter is None: + self._total_tokens = value + return + + self._limiter.total_tokens = value + + @property + def borrowed_tokens(self) -> int: + if self._internal_limiter is None: + return 0 + + return self._internal_limiter.borrowed_tokens + + @property + def available_tokens(self) -> float: + if self._internal_limiter is None: + return self._total_tokens + + return self._internal_limiter.available_tokens + + def acquire_nowait(self) -> None: + self._limiter.acquire_nowait() + + def acquire_on_behalf_of_nowait(self, borrower: object) -> None: + self._limiter.acquire_on_behalf_of_nowait(borrower) + + async def acquire(self) -> None: + await self._limiter.acquire() + + async def acquire_on_behalf_of(self, borrower: object) -> None: + await self._limiter.acquire_on_behalf_of(borrower) + + def release(self) -> None: + self._limiter.release() + + def release_on_behalf_of(self, borrower: object) -> None: + self._limiter.release_on_behalf_of(borrower) + + def statistics(self) -> CapacityLimiterStatistics: + if self._internal_limiter is None: + return CapacityLimiterStatistics( + borrowed_tokens=0, + total_tokens=self.total_tokens, + borrowers=(), + tasks_waiting=0, + ) + + return self._internal_limiter.statistics() + + +class ResourceGuard: + """ + A context manager for ensuring that a resource is only used by a single task at a + time. + + Entering this context manager while the previous has not exited it yet will trigger + :exc:`BusyResourceError`. + + :param action: the action to guard against (visible in the :exc:`BusyResourceError` + when triggered, e.g. "Another task is already {action} this resource") + + .. versionadded:: 4.1 + """ + + __slots__ = "action", "_guarded" + + def __init__(self, action: str = "using"): + self.action: str = action + self._guarded = False + + def __enter__(self) -> None: + if self._guarded: + raise BusyResourceError(self.action) + + self._guarded = True + + def __exit__( + self, + exc_type: type[BaseException] | None, + exc_val: BaseException | None, + exc_tb: TracebackType | None, + ) -> None: + self._guarded = False |