Move move context code into new `._context` mod
Tyler Goodlet
parent
97446b84c0
commit
c7b56ae639
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@ -15,18 +15,20 @@
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# along with this program. If not, see <https://www.gnu.org/licenses/>.
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"""
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tractor: structured concurrent "actors".
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tractor: structured concurrent ``trio``-"actors".
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"""
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from exceptiongroup import BaseExceptionGroup
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from ._clustering import open_actor_cluster
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from ._ipc import Channel
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from ._streaming import (
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from ._context import (
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Context,
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context,
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)
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from ._streaming import (
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MsgStream,
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stream,
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context,
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)
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from ._discovery import (
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get_arbiter,
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@ -0,0 +1,767 @@
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# tractor: structured concurrent "actors".
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# Copyright 2018-eternity Tyler Goodlet.
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# This program is free software: you can redistribute it and/or modify
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# it under the terms of the GNU Affero General Public License as published by
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# the Free Software Foundation, either version 3 of the License, or
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# (at your option) any later version.
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# This program is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU Affero General Public License for more details.
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# You should have received a copy of the GNU Affero General Public License
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# along with this program. If not, see <https://www.gnu.org/licenses/>.
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'''
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The fundamental cross process SC abstraction: an inter-actor,
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cancel-scope linked task "context".
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A ``Context`` is very similar to the ``trio.Nursery.cancel_scope`` built
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into each ``trio.Nursery`` except it links the lifetimes of memory space
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disjoint, parallel executing tasks in separate actors.
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'''
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from __future__ import annotations
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from collections import deque
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from contextlib import asynccontextmanager as acm
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from dataclasses import (
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dataclass,
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field,
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)
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from functools import partial
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import inspect
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from pprint import pformat
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from typing import (
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Any,
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Callable,
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AsyncGenerator,
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TYPE_CHECKING,
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)
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import warnings
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import trio
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from ._exceptions import (
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unpack_error,
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pack_error,
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ContextCancelled,
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StreamOverrun,
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)
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from .log import get_logger
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from ._ipc import Channel
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from ._streaming import MsgStream
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from ._state import current_actor
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if TYPE_CHECKING:
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from ._portal import Portal
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log = get_logger(__name__)
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@dataclass
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class Context:
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'''
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An inter-actor, ``trio`` task communication context.
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NB: This class should never be instatiated directly, it is delivered
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by either,
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- runtime machinery to a remotely started task or,
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- by entering ``Portal.open_context()``.
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Allows maintaining task or protocol specific state between
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2 communicating actor tasks. A unique context is created on the
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callee side/end for every request to a remote actor from a portal.
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A context can be cancelled and (possibly eventually restarted) from
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either side of the underlying IPC channel, open task oriented
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message streams and acts as an IPC aware inter-actor-task cancel
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scope.
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'''
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chan: Channel
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cid: str
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# these are the "feeder" channels for delivering
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# message values to the local task from the runtime
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# msg processing loop.
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_recv_chan: trio.MemoryReceiveChannel
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_send_chan: trio.MemorySendChannel
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_remote_func_type: str | None = None
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# only set on the caller side
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_portal: Portal | None = None # type: ignore # noqa
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_result: Any | int = None
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_remote_error: BaseException | None = None
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# cancellation state
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_cancel_called: bool = False
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_cancel_called_remote: tuple | None = None
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_cancel_msg: str | None = None
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_scope: trio.CancelScope | None = None
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_enter_debugger_on_cancel: bool = True
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@property
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def cancel_called(self) -> bool:
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'''
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Records whether cancellation has been requested for this context
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by either an explicit call to ``.cancel()`` or an implicit call
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due to an error caught inside the ``Portal.open_context()``
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block.
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'''
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return self._cancel_called
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@property
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def cancel_called_remote(self) -> tuple[str, str] | None:
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'''
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``Actor.uid`` of the remote actor who's task was cancelled
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causing this side of the context to also be cancelled.
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'''
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remote_uid = self._cancel_called_remote
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if remote_uid:
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return tuple(remote_uid)
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@property
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def cancelled_caught(self) -> bool:
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return self._scope.cancelled_caught
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# init and streaming state
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_started_called: bool = False
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_started_received: bool = False
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_stream_opened: bool = False
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# overrun handling machinery
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# NOTE: none of this provides "backpressure" to the remote
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# task, only an ability to not lose messages when the local
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# task is configured to NOT transmit ``StreamOverrun``s back
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# to the other side.
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_overflow_q: deque[dict] = field(
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default_factory=partial(
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deque,
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maxlen=616,
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)
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)
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_scope_nursery: trio.Nursery | None = None
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_in_overrun: bool = False
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_allow_overruns: bool = False
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async def send_yield(
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self,
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data: Any,
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) -> None:
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warnings.warn(
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"`Context.send_yield()` is now deprecated. "
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"Use ``MessageStream.send()``. ",
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DeprecationWarning,
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stacklevel=2,
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)
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await self.chan.send({'yield': data, 'cid': self.cid})
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async def send_stop(self) -> None:
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await self.chan.send({'stop': True, 'cid': self.cid})
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async def _maybe_cancel_and_set_remote_error(
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self,
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error_msg: dict[str, Any],
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) -> None:
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'''
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(Maybe) unpack and raise a msg error into the local scope
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nursery for this context.
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Acts as a form of "relay" for a remote error raised
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in the corresponding remote callee task.
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'''
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# If this is an error message from a context opened by
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# ``Portal.open_context()`` we want to interrupt any ongoing
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# (child) tasks within that context to be notified of the remote
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# error relayed here.
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#
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# The reason we may want to raise the remote error immediately
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# is that there is no guarantee the associated local task(s)
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# will attempt to read from any locally opened stream any time
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# soon.
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#
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# NOTE: this only applies when
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# ``Portal.open_context()`` has been called since it is assumed
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# (currently) that other portal APIs (``Portal.run()``,
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# ``.run_in_actor()``) do their own error checking at the point
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# of the call and result processing.
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error = unpack_error(
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error_msg,
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self.chan,
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)
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# XXX: set the remote side's error so that after we cancel
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# whatever task is the opener of this context it can raise
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# that error as the reason.
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self._remote_error = error
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if (
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isinstance(error, ContextCancelled)
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):
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log.cancel(
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'Remote task-context sucessfully cancelled for '
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f'{self.chan.uid}:{self.cid}'
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)
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if self._cancel_called:
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# this is an expected cancel request response message
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# and we don't need to raise it in scope since it will
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# potentially override a real error
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return
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else:
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log.error(
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f'Remote context error for {self.chan.uid}:{self.cid}:\n'
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f'{error_msg["error"]["tb_str"]}'
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)
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# TODO: tempted to **not** do this by-reraising in a
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# nursery and instead cancel a surrounding scope, detect
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# the cancellation, then lookup the error that was set?
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# YES! this is way better and simpler!
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if (
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self._scope
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):
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# from trio.testing import wait_all_tasks_blocked
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# await wait_all_tasks_blocked()
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self._cancel_called_remote = self.chan.uid
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self._scope.cancel()
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# NOTE: this usage actually works here B)
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# from ._debug import breakpoint
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# await breakpoint()
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# XXX: this will break early callee results sending
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# since when `.result()` is finally called, this
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# chan will be closed..
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# if self._recv_chan:
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# await self._recv_chan.aclose()
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async def cancel(
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self,
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msg: str | None = None,
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timeout: float = 0.5,
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# timeout: float = 1000,
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) -> None:
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'''
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Cancel this inter-actor-task context.
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Request that the far side cancel it's current linked context,
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Timeout quickly in an attempt to sidestep 2-generals...
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'''
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side = 'caller' if self._portal else 'callee'
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if msg:
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assert side == 'callee', 'Only callee side can provide cancel msg'
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log.cancel(f'Cancelling {side} side of context to {self.chan.uid}')
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self._cancel_called = True
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# await _debug.breakpoint()
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# breakpoint()
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if side == 'caller':
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if not self._portal:
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raise RuntimeError(
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"No portal found, this is likely a callee side context"
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)
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cid = self.cid
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with trio.move_on_after(timeout) as cs:
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# cs.shield = True
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log.cancel(
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f"Cancelling stream {cid} to "
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f"{self._portal.channel.uid}")
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# NOTE: we're telling the far end actor to cancel a task
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# corresponding to *this actor*. The far end local channel
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# instance is passed to `Actor._cancel_task()` implicitly.
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await self._portal.run_from_ns(
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'self',
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'_cancel_task',
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cid=cid,
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)
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# print("EXITING CANCEL CALL")
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if cs.cancelled_caught:
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# XXX: there's no way to know if the remote task was indeed
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# cancelled in the case where the connection is broken or
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# some other network error occurred.
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# if not self._portal.channel.connected():
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if not self.chan.connected():
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log.cancel(
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"May have failed to cancel remote task "
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f"{cid} for {self._portal.channel.uid}")
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else:
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log.cancel(
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"Timed out on cancelling remote task "
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f"{cid} for {self._portal.channel.uid}")
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# callee side remote task
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else:
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self._cancel_msg = msg
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# TODO: should we have an explicit cancel message
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# or is relaying the local `trio.Cancelled` as an
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# {'error': trio.Cancelled, cid: "blah"} enough?
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# This probably gets into the discussion in
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# https://github.com/goodboy/tractor/issues/36
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assert self._scope
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self._scope.cancel()
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@acm
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async def open_stream(
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self,
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allow_overruns: bool | None = False,
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msg_buffer_size: int | None = None,
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) -> AsyncGenerator[MsgStream, None]:
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'''
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Open a ``MsgStream``, a bi-directional stream connected to the
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cross-actor (far end) task for this ``Context``.
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This context manager must be entered on both the caller and
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callee for the stream to logically be considered "connected".
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A ``MsgStream`` is currently "one-shot" use, meaning if you
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close it you can not "re-open" it for streaming and instead you
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must re-establish a new surrounding ``Context`` using
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``Portal.open_context()``. In the future this may change but
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currently there seems to be no obvious reason to support
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"re-opening":
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- pausing a stream can be done with a message.
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- task errors will normally require a restart of the entire
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scope of the inter-actor task context due to the nature of
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``trio``'s cancellation system.
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'''
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actor = current_actor()
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# here we create a mem chan that corresponds to the
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# far end caller / callee.
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# Likewise if the surrounding context has been cancelled we error here
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# since it likely means the surrounding block was exited or
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# killed
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if self._cancel_called:
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task = trio.lowlevel.current_task().name
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raise ContextCancelled(
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f'Context around {actor.uid[0]}:{task} was already cancelled!'
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)
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if not self._portal and not self._started_called:
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raise RuntimeError(
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'Context.started()` must be called before opening a stream'
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)
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# NOTE: in one way streaming this only happens on the
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# caller side inside `Actor.start_remote_task()` so if you try
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# to send a stop from the caller to the callee in the
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# single-direction-stream case you'll get a lookup error
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# currently.
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ctx = actor.get_context(
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self.chan,
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self.cid,
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msg_buffer_size=msg_buffer_size,
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allow_overruns=allow_overruns,
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)
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ctx._allow_overruns = allow_overruns
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assert ctx is self
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# XXX: If the underlying channel feeder receive mem chan has
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# been closed then likely client code has already exited
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# a ``.open_stream()`` block prior or there was some other
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# unanticipated error or cancellation from ``trio``.
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if ctx._recv_chan._closed:
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raise trio.ClosedResourceError(
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'The underlying channel for this stream was already closed!?')
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async with MsgStream(
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ctx=self,
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rx_chan=ctx._recv_chan,
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) as stream:
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if self._portal:
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self._portal._streams.add(stream)
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try:
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self._stream_opened = True
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# XXX: do we need this?
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# ensure we aren't cancelled before yielding the stream
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# await trio.lowlevel.checkpoint()
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yield stream
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# NOTE: Make the stream "one-shot use". On exit, signal
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# ``trio.EndOfChannel``/``StopAsyncIteration`` to the
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# far end.
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await stream.aclose()
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finally:
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if self._portal:
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try:
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self._portal._streams.remove(stream)
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except KeyError:
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log.warning(
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f'Stream was already destroyed?\n'
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f'actor: {self.chan.uid}\n'
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f'ctx id: {self.cid}'
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)
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def _maybe_raise_remote_err(
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self,
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err: Exception,
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) -> None:
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# NOTE: whenever the context's "opener" side (task) **is**
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# the side which requested the cancellation (likekly via
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# ``Context.cancel()``), we don't want to re-raise that
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# cancellation signal locally (would be akin to
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# a ``trio.Nursery`` nursery raising ``trio.Cancelled``
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# whenever ``CancelScope.cancel()`` was called) and instead
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# silently reap the expected cancellation "error"-msg.
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# if 'pikerd' in err.msgdata['tb_str']:
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# # from . import _debug
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# # await _debug.breakpoint()
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# breakpoint()
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if (
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isinstance(err, ContextCancelled)
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and (
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self._cancel_called
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or self.chan._cancel_called
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or tuple(err.canceller) == current_actor().uid
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)
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):
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return err
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raise err # from None
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async def result(self) -> Any | Exception:
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'''
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From some (caller) side task, wait for and return the final
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result from the remote (callee) side's task.
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This provides a mechanism for one task running in some actor to wait
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on another task at the other side, in some other actor, to terminate.
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If the remote task is still in a streaming state (it is delivering
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values from inside a ``Context.open_stream():`` block, then those
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msgs are drained but discarded since it is presumed this side of
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the context has already finished with its own streaming logic.
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If the remote context (or its containing actor runtime) was
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canceled, either by a local task calling one of
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``Context.cancel()`` or `Portal.cancel_actor()``, we ignore the
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received ``ContextCancelled`` exception if the context or
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underlying IPC channel is marked as having been "cancel called".
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This is similar behavior to using ``trio.Nursery.cancel()``
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wherein tasks which raise ``trio.Cancel`` are silently reaped;
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the main different in this API is in the "cancel called" case,
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instead of just not raising, we also return the exception *as
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the result* since client code may be interested in the details
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of the remote cancellation.
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'''
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assert self._portal, "Context.result() can not be called from callee!"
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assert self._recv_chan
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# from . import _debug
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# await _debug.breakpoint()
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|
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re = self._remote_error
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if re:
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self._maybe_raise_remote_err(re)
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return re
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|
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if (
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self._result == id(self)
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and not self._remote_error
|
||||
and not self._recv_chan._closed # type: ignore
|
||||
):
|
||||
# wait for a final context result consuming
|
||||
# and discarding any bi dir stream msgs still
|
||||
# in transit from the far end.
|
||||
while True:
|
||||
msg = await self._recv_chan.receive()
|
||||
try:
|
||||
self._result = msg['return']
|
||||
|
||||
# NOTE: we don't need to do this right?
|
||||
# XXX: only close the rx mem chan AFTER
|
||||
# a final result is retreived.
|
||||
# if self._recv_chan:
|
||||
# await self._recv_chan.aclose()
|
||||
|
||||
break
|
||||
except KeyError: # as msgerr:
|
||||
|
||||
if 'yield' in msg:
|
||||
# far end task is still streaming to us so discard
|
||||
log.warning(f'Discarding stream delivered {msg}')
|
||||
continue
|
||||
|
||||
elif 'stop' in msg:
|
||||
log.debug('Remote stream terminated')
|
||||
continue
|
||||
|
||||
# internal error should never get here
|
||||
assert msg.get('cid'), (
|
||||
"Received internal error at portal?")
|
||||
|
||||
err = unpack_error(
|
||||
msg,
|
||||
self._portal.channel
|
||||
) # from msgerr
|
||||
|
||||
err = self._maybe_raise_remote_err(err)
|
||||
self._remote_err = err
|
||||
|
||||
return self._remote_error or self._result
|
||||
|
||||
async def started(
|
||||
self,
|
||||
value: Any | None = None
|
||||
|
||||
) -> None:
|
||||
'''
|
||||
Indicate to calling actor's task that this linked context
|
||||
has started and send ``value`` to the other side.
|
||||
|
||||
On the calling side ``value`` is the second item delivered
|
||||
in the tuple returned by ``Portal.open_context()``.
|
||||
|
||||
'''
|
||||
if self._portal:
|
||||
raise RuntimeError(
|
||||
f"Caller side context {self} can not call started!")
|
||||
|
||||
elif self._started_called:
|
||||
raise RuntimeError(
|
||||
f"called 'started' twice on context with {self.chan.uid}")
|
||||
|
||||
await self.chan.send({'started': value, 'cid': self.cid})
|
||||
self._started_called = True
|
||||
|
||||
# TODO: do we need a restart api?
|
||||
# async def restart(self) -> None:
|
||||
# pass
|
||||
|
||||
async def _drain_overflows(
|
||||
self,
|
||||
) -> None:
|
||||
'''
|
||||
Private task spawned to push newly received msgs to the local
|
||||
task which getting overrun by the remote side.
|
||||
|
||||
In order to not block the rpc msg loop, but also not discard
|
||||
msgs received in this context, we need to async push msgs in
|
||||
a new task which only runs for as long as the local task is in
|
||||
an overrun state.
|
||||
|
||||
'''
|
||||
self._in_overrun = True
|
||||
try:
|
||||
while self._overflow_q:
|
||||
# NOTE: these msgs should never be errors since we always do
|
||||
# the check prior to checking if we're in an overrun state
|
||||
# inside ``.deliver_msg()``.
|
||||
msg = self._overflow_q.popleft()
|
||||
try:
|
||||
await self._send_chan.send(msg)
|
||||
except trio.BrokenResourceError:
|
||||
log.warning(
|
||||
f"{self._send_chan} consumer is already closed"
|
||||
)
|
||||
return
|
||||
except trio.Cancelled:
|
||||
# we are obviously still in overrun
|
||||
# but the context is being closed anyway
|
||||
# so we just warn that there are un received
|
||||
# msgs still..
|
||||
self._overflow_q.appendleft(msg)
|
||||
fmt_msgs = ''
|
||||
for msg in self._overflow_q:
|
||||
fmt_msgs += f'{pformat(msg)}\n'
|
||||
|
||||
log.warning(
|
||||
f'Context for {self.cid} is being closed while '
|
||||
'in an overrun state!\n'
|
||||
'Discarding the following msgs:\n'
|
||||
f'{fmt_msgs}\n'
|
||||
)
|
||||
raise
|
||||
|
||||
finally:
|
||||
# task is now finished with the backlog so mark us as
|
||||
# no longer in backlog.
|
||||
self._in_overrun = False
|
||||
|
||||
async def _deliver_msg(
|
||||
self,
|
||||
msg: dict,
|
||||
|
||||
draining: bool = False,
|
||||
|
||||
) -> bool:
|
||||
|
||||
cid = self.cid
|
||||
chan = self.chan
|
||||
uid = chan.uid
|
||||
send_chan: trio.MemorySendChannel = self._send_chan
|
||||
|
||||
log.runtime(
|
||||
f"Delivering {msg} from {uid} to caller {cid}"
|
||||
)
|
||||
|
||||
error = msg.get('error')
|
||||
if error:
|
||||
await self._maybe_cancel_and_set_remote_error(msg)
|
||||
|
||||
if (
|
||||
self._in_overrun
|
||||
):
|
||||
self._overflow_q.append(msg)
|
||||
return False
|
||||
|
||||
try:
|
||||
send_chan.send_nowait(msg)
|
||||
return True
|
||||
# if an error is deteced we should always
|
||||
# expect it to be raised by any context (stream)
|
||||
# consumer task
|
||||
|
||||
except trio.BrokenResourceError:
|
||||
# TODO: what is the right way to handle the case where the
|
||||
# local task has already sent a 'stop' / StopAsyncInteration
|
||||
# to the other side but and possibly has closed the local
|
||||
# feeder mem chan? Do we wait for some kind of ack or just
|
||||
# let this fail silently and bubble up (currently)?
|
||||
|
||||
# XXX: local consumer has closed their side
|
||||
# so cancel the far end streaming task
|
||||
log.warning(f"{send_chan} consumer is already closed")
|
||||
return False
|
||||
|
||||
# NOTE XXX: by default we do **not** maintain context-stream
|
||||
# backpressure and instead opt to relay stream overrun errors to
|
||||
# the sender; the main motivation is that using bp can block the
|
||||
# msg handling loop which calls into this method!
|
||||
except trio.WouldBlock:
|
||||
# XXX: always push an error even if the local
|
||||
# receiver is in overrun state.
|
||||
# await self._maybe_cancel_and_set_remote_error(msg)
|
||||
|
||||
local_uid = current_actor().uid
|
||||
lines = [
|
||||
f'OVERRUN on actor-task context {cid}@{local_uid}!\n'
|
||||
# TODO: put remote task name here if possible?
|
||||
f'remote sender actor: {uid}',
|
||||
# TODO: put task func name here and maybe an arrow
|
||||
# from sender to overrunner?
|
||||
# f'local task {self.func_name}'
|
||||
]
|
||||
if not self._stream_opened:
|
||||
lines.insert(
|
||||
1,
|
||||
f'\n*** No stream open on `{local_uid[0]}` side! ***\n'
|
||||
)
|
||||
|
||||
text = '\n'.join(lines)
|
||||
|
||||
# XXX: lul, this really can't be backpressure since any
|
||||
# blocking here will block the entire msg loop rpc sched for
|
||||
# a whole channel.. maybe we should rename it?
|
||||
if self._allow_overruns:
|
||||
text += f'\nStarting overflow queuing task on msg: {msg}'
|
||||
log.warning(text)
|
||||
if (
|
||||
not self._in_overrun
|
||||
):
|
||||
self._overflow_q.append(msg)
|
||||
n = self._scope_nursery
|
||||
assert not n.child_tasks
|
||||
try:
|
||||
n.start_soon(
|
||||
self._drain_overflows,
|
||||
)
|
||||
except RuntimeError:
|
||||
# if the nursery is already cancelled due to
|
||||
# this context exiting or in error, we ignore
|
||||
# the nursery error since we never expected
|
||||
# anything different.
|
||||
return False
|
||||
else:
|
||||
try:
|
||||
raise StreamOverrun(text)
|
||||
except StreamOverrun as err:
|
||||
err_msg = pack_error(err)
|
||||
err_msg['cid'] = cid
|
||||
try:
|
||||
await chan.send(err_msg)
|
||||
except trio.BrokenResourceError:
|
||||
# XXX: local consumer has closed their side
|
||||
# so cancel the far end streaming task
|
||||
log.warning(f"{chan} is already closed")
|
||||
|
||||
return False
|
||||
|
||||
|
||||
def mk_context(
|
||||
chan: Channel,
|
||||
cid: str,
|
||||
msg_buffer_size: int = 2**6,
|
||||
|
||||
**kwargs,
|
||||
|
||||
) -> Context:
|
||||
'''
|
||||
Internal factory to create an inter-actor task ``Context``.
|
||||
|
||||
This is called by internals and should generally never be called
|
||||
by user code.
|
||||
|
||||
'''
|
||||
send_chan: trio.MemorySendChannel
|
||||
recv_chan: trio.MemoryReceiveChannel
|
||||
send_chan, recv_chan = trio.open_memory_channel(msg_buffer_size)
|
||||
|
||||
ctx = Context(
|
||||
chan,
|
||||
cid,
|
||||
_send_chan=send_chan,
|
||||
_recv_chan=recv_chan,
|
||||
**kwargs,
|
||||
)
|
||||
ctx._result = id(ctx)
|
||||
return ctx
|
||||
|
||||
|
||||
def context(func: Callable) -> Callable:
|
||||
'''
|
||||
Mark an async function as a streaming routine with ``@context``.
|
||||
|
||||
'''
|
||||
# TODO: apply whatever solution ``mypy`` ends up picking for this:
|
||||
# https://github.com/python/mypy/issues/2087#issuecomment-769266912
|
||||
func._tractor_context_function = True # type: ignore
|
||||
|
||||
sig = inspect.signature(func)
|
||||
params = sig.parameters
|
||||
if 'ctx' not in params:
|
||||
raise TypeError(
|
||||
"The first argument to the context function "
|
||||
f"{func.__name__} must be `ctx: tractor.Context`"
|
||||
)
|
||||
return func
|
||||
|
|
@ -45,10 +45,8 @@ from ._exceptions import (
|
|||
NoResult,
|
||||
ContextCancelled,
|
||||
)
|
||||
from ._streaming import (
|
||||
Context,
|
||||
MsgStream,
|
||||
)
|
||||
from ._context import Context
|
||||
from ._streaming import MsgStream
|
||||
|
||||
|
||||
log = get_logger(__name__)
|
||||
|
|
|
|||
|
|
@ -46,7 +46,7 @@ import trio # type: ignore
|
|||
from trio_typing import TaskStatus
|
||||
|
||||
from ._ipc import Channel
|
||||
from ._streaming import (
|
||||
from ._context import (
|
||||
mk_context,
|
||||
Context,
|
||||
)
|
||||
|
|
|
|||
|
|
@ -14,25 +14,18 @@
|
|||
# You should have received a copy of the GNU Affero General Public License
|
||||
# along with this program. If not, see <https://www.gnu.org/licenses/>.
|
||||
|
||||
"""
|
||||
'''
|
||||
Message stream types and APIs.
|
||||
|
||||
"""
|
||||
The machinery and types behind ``Context.open_stream()``
|
||||
|
||||
'''
|
||||
from __future__ import annotations
|
||||
import inspect
|
||||
from contextlib import asynccontextmanager
|
||||
from collections import deque
|
||||
from dataclasses import (
|
||||
dataclass,
|
||||
field,
|
||||
)
|
||||
from functools import partial
|
||||
from pprint import pformat
|
||||
from contextlib import asynccontextmanager as acm
|
||||
from typing import (
|
||||
Any,
|
||||
Optional,
|
||||
Callable,
|
||||
AsyncGenerator,
|
||||
AsyncIterator,
|
||||
TYPE_CHECKING,
|
||||
)
|
||||
|
|
@ -40,22 +33,17 @@ import warnings
|
|||
|
||||
import trio
|
||||
|
||||
from ._ipc import Channel
|
||||
from ._exceptions import (
|
||||
unpack_error,
|
||||
pack_error,
|
||||
ContextCancelled,
|
||||
StreamOverrun,
|
||||
)
|
||||
from .log import get_logger
|
||||
from ._state import current_actor
|
||||
from .trionics import (
|
||||
broadcast_receiver,
|
||||
BroadcastReceiver,
|
||||
)
|
||||
|
||||
if TYPE_CHECKING:
|
||||
from ._portal import Portal
|
||||
from ._context import Context
|
||||
|
||||
|
||||
log = get_logger(__name__)
|
||||
|
|
@ -87,9 +75,9 @@ class MsgStream(trio.abc.Channel):
|
|||
'''
|
||||
def __init__(
|
||||
self,
|
||||
ctx: 'Context', # typing: ignore # noqa
|
||||
ctx: Context, # typing: ignore # noqa
|
||||
rx_chan: trio.MemoryReceiveChannel,
|
||||
_broadcaster: Optional[BroadcastReceiver] = None,
|
||||
_broadcaster: BroadcastReceiver | None = None,
|
||||
|
||||
) -> None:
|
||||
self._ctx = ctx
|
||||
|
|
@ -292,7 +280,7 @@ class MsgStream(trio.abc.Channel):
|
|||
# still need to consume msgs that are "in transit" from the far
|
||||
# end (eg. for ``Context.result()``).
|
||||
|
||||
@asynccontextmanager
|
||||
@acm
|
||||
async def subscribe(
|
||||
self,
|
||||
|
||||
|
|
@ -361,693 +349,6 @@ class MsgStream(trio.abc.Channel):
|
|||
await self._ctx.chan.send({'yield': data, 'cid': self._ctx.cid})
|
||||
|
||||
|
||||
@dataclass
|
||||
class Context:
|
||||
'''
|
||||
An inter-actor, ``trio`` task communication context.
|
||||
|
||||
NB: This class should never be instatiated directly, it is delivered
|
||||
by either,
|
||||
- runtime machinery to a remotely started task or,
|
||||
- by entering ``Portal.open_context()``.
|
||||
|
||||
Allows maintaining task or protocol specific state between
|
||||
2 communicating actor tasks. A unique context is created on the
|
||||
callee side/end for every request to a remote actor from a portal.
|
||||
|
||||
A context can be cancelled and (possibly eventually restarted) from
|
||||
either side of the underlying IPC channel, open task oriented
|
||||
message streams and acts as an IPC aware inter-actor-task cancel
|
||||
scope.
|
||||
|
||||
'''
|
||||
chan: Channel
|
||||
cid: str
|
||||
|
||||
# these are the "feeder" channels for delivering
|
||||
# message values to the local task from the runtime
|
||||
# msg processing loop.
|
||||
_recv_chan: trio.MemoryReceiveChannel
|
||||
_send_chan: trio.MemorySendChannel
|
||||
|
||||
_remote_func_type: str | None = None
|
||||
|
||||
# only set on the caller side
|
||||
_portal: Portal | None = None # type: ignore # noqa
|
||||
_result: Any | int = None
|
||||
_remote_error: BaseException | None = None
|
||||
|
||||
# cancellation state
|
||||
_cancel_called: bool = False
|
||||
_cancel_called_remote: tuple | None = None
|
||||
_cancel_msg: str | None = None
|
||||
_scope: trio.CancelScope | None = None
|
||||
_enter_debugger_on_cancel: bool = True
|
||||
|
||||
@property
|
||||
def cancel_called(self) -> bool:
|
||||
'''
|
||||
Records whether cancellation has been requested for this context
|
||||
by either an explicit call to ``.cancel()`` or an implicit call
|
||||
due to an error caught inside the ``Portal.open_context()``
|
||||
block.
|
||||
|
||||
'''
|
||||
return self._cancel_called
|
||||
|
||||
@property
|
||||
def cancel_called_remote(self) -> tuple[str, str] | None:
|
||||
'''
|
||||
``Actor.uid`` of the remote actor who's task was cancelled
|
||||
causing this side of the context to also be cancelled.
|
||||
|
||||
'''
|
||||
remote_uid = self._cancel_called_remote
|
||||
if remote_uid:
|
||||
return tuple(remote_uid)
|
||||
|
||||
@property
|
||||
def cancelled_caught(self) -> bool:
|
||||
return self._scope.cancelled_caught
|
||||
|
||||
# init and streaming state
|
||||
_started_called: bool = False
|
||||
_started_received: bool = False
|
||||
_stream_opened: bool = False
|
||||
|
||||
# overrun handling machinery
|
||||
# NOTE: none of this provides "backpressure" to the remote
|
||||
# task, only an ability to not lose messages when the local
|
||||
# task is configured to NOT transmit ``StreamOverrun``s back
|
||||
# to the other side.
|
||||
_overflow_q: deque[dict] = field(
|
||||
default_factory=partial(
|
||||
deque,
|
||||
maxlen=616,
|
||||
)
|
||||
)
|
||||
_scope_nursery: trio.Nursery | None = None
|
||||
_in_overrun: bool = False
|
||||
_allow_overruns: bool = False
|
||||
|
||||
async def send_yield(
|
||||
self,
|
||||
data: Any,
|
||||
|
||||
) -> None:
|
||||
|
||||
warnings.warn(
|
||||
"`Context.send_yield()` is now deprecated. "
|
||||
"Use ``MessageStream.send()``. ",
|
||||
DeprecationWarning,
|
||||
stacklevel=2,
|
||||
)
|
||||
await self.chan.send({'yield': data, 'cid': self.cid})
|
||||
|
||||
async def send_stop(self) -> None:
|
||||
await self.chan.send({'stop': True, 'cid': self.cid})
|
||||
|
||||
async def _maybe_cancel_and_set_remote_error(
|
||||
self,
|
||||
error_msg: dict[str, Any],
|
||||
|
||||
) -> None:
|
||||
'''
|
||||
(Maybe) unpack and raise a msg error into the local scope
|
||||
nursery for this context.
|
||||
|
||||
Acts as a form of "relay" for a remote error raised
|
||||
in the corresponding remote callee task.
|
||||
|
||||
'''
|
||||
# If this is an error message from a context opened by
|
||||
# ``Portal.open_context()`` we want to interrupt any ongoing
|
||||
# (child) tasks within that context to be notified of the remote
|
||||
# error relayed here.
|
||||
#
|
||||
# The reason we may want to raise the remote error immediately
|
||||
# is that there is no guarantee the associated local task(s)
|
||||
# will attempt to read from any locally opened stream any time
|
||||
# soon.
|
||||
#
|
||||
# NOTE: this only applies when
|
||||
# ``Portal.open_context()`` has been called since it is assumed
|
||||
# (currently) that other portal APIs (``Portal.run()``,
|
||||
# ``.run_in_actor()``) do their own error checking at the point
|
||||
# of the call and result processing.
|
||||
error = unpack_error(
|
||||
error_msg,
|
||||
self.chan,
|
||||
)
|
||||
|
||||
# XXX: set the remote side's error so that after we cancel
|
||||
# whatever task is the opener of this context it can raise
|
||||
# that error as the reason.
|
||||
self._remote_error = error
|
||||
|
||||
if (
|
||||
isinstance(error, ContextCancelled)
|
||||
):
|
||||
log.cancel(
|
||||
'Remote task-context sucessfully cancelled for '
|
||||
f'{self.chan.uid}:{self.cid}'
|
||||
)
|
||||
|
||||
if self._cancel_called:
|
||||
# this is an expected cancel request response message
|
||||
# and we don't need to raise it in scope since it will
|
||||
# potentially override a real error
|
||||
return
|
||||
else:
|
||||
log.error(
|
||||
f'Remote context error for {self.chan.uid}:{self.cid}:\n'
|
||||
f'{error_msg["error"]["tb_str"]}'
|
||||
)
|
||||
# TODO: tempted to **not** do this by-reraising in a
|
||||
# nursery and instead cancel a surrounding scope, detect
|
||||
# the cancellation, then lookup the error that was set?
|
||||
# YES! this is way better and simpler!
|
||||
if (
|
||||
self._scope
|
||||
):
|
||||
# from trio.testing import wait_all_tasks_blocked
|
||||
# await wait_all_tasks_blocked()
|
||||
self._cancel_called_remote = self.chan.uid
|
||||
self._scope.cancel()
|
||||
|
||||
# NOTE: this usage actually works here B)
|
||||
# from ._debug import breakpoint
|
||||
# await breakpoint()
|
||||
|
||||
# XXX: this will break early callee results sending
|
||||
# since when `.result()` is finally called, this
|
||||
# chan will be closed..
|
||||
# if self._recv_chan:
|
||||
# await self._recv_chan.aclose()
|
||||
|
||||
async def cancel(
|
||||
self,
|
||||
msg: str | None = None,
|
||||
timeout: float = 0.5,
|
||||
# timeout: float = 1000,
|
||||
|
||||
) -> None:
|
||||
'''
|
||||
Cancel this inter-actor-task context.
|
||||
|
||||
Request that the far side cancel it's current linked context,
|
||||
Timeout quickly in an attempt to sidestep 2-generals...
|
||||
|
||||
'''
|
||||
side = 'caller' if self._portal else 'callee'
|
||||
if msg:
|
||||
assert side == 'callee', 'Only callee side can provide cancel msg'
|
||||
|
||||
log.cancel(f'Cancelling {side} side of context to {self.chan.uid}')
|
||||
|
||||
self._cancel_called = True
|
||||
# await _debug.breakpoint()
|
||||
# breakpoint()
|
||||
|
||||
if side == 'caller':
|
||||
if not self._portal:
|
||||
raise RuntimeError(
|
||||
"No portal found, this is likely a callee side context"
|
||||
)
|
||||
|
||||
cid = self.cid
|
||||
with trio.move_on_after(timeout) as cs:
|
||||
# cs.shield = True
|
||||
log.cancel(
|
||||
f"Cancelling stream {cid} to "
|
||||
f"{self._portal.channel.uid}")
|
||||
|
||||
# NOTE: we're telling the far end actor to cancel a task
|
||||
# corresponding to *this actor*. The far end local channel
|
||||
# instance is passed to `Actor._cancel_task()` implicitly.
|
||||
await self._portal.run_from_ns(
|
||||
'self',
|
||||
'_cancel_task',
|
||||
cid=cid,
|
||||
)
|
||||
# print("EXITING CANCEL CALL")
|
||||
|
||||
if cs.cancelled_caught:
|
||||
# XXX: there's no way to know if the remote task was indeed
|
||||
# cancelled in the case where the connection is broken or
|
||||
# some other network error occurred.
|
||||
# if not self._portal.channel.connected():
|
||||
if not self.chan.connected():
|
||||
log.cancel(
|
||||
"May have failed to cancel remote task "
|
||||
f"{cid} for {self._portal.channel.uid}")
|
||||
else:
|
||||
log.cancel(
|
||||
"Timed out on cancelling remote task "
|
||||
f"{cid} for {self._portal.channel.uid}")
|
||||
|
||||
# callee side remote task
|
||||
else:
|
||||
self._cancel_msg = msg
|
||||
|
||||
# TODO: should we have an explicit cancel message
|
||||
# or is relaying the local `trio.Cancelled` as an
|
||||
# {'error': trio.Cancelled, cid: "blah"} enough?
|
||||
# This probably gets into the discussion in
|
||||
# https://github.com/goodboy/tractor/issues/36
|
||||
assert self._scope
|
||||
self._scope.cancel()
|
||||
|
||||
@asynccontextmanager
|
||||
async def open_stream(
|
||||
|
||||
self,
|
||||
allow_overruns: bool | None = False,
|
||||
msg_buffer_size: int | None = None,
|
||||
|
||||
) -> AsyncGenerator[MsgStream, None]:
|
||||
'''
|
||||
Open a ``MsgStream``, a bi-directional stream connected to the
|
||||
cross-actor (far end) task for this ``Context``.
|
||||
|
||||
This context manager must be entered on both the caller and
|
||||
callee for the stream to logically be considered "connected".
|
||||
|
||||
A ``MsgStream`` is currently "one-shot" use, meaning if you
|
||||
close it you can not "re-open" it for streaming and instead you
|
||||
must re-establish a new surrounding ``Context`` using
|
||||
``Portal.open_context()``. In the future this may change but
|
||||
currently there seems to be no obvious reason to support
|
||||
"re-opening":
|
||||
- pausing a stream can be done with a message.
|
||||
- task errors will normally require a restart of the entire
|
||||
scope of the inter-actor task context due to the nature of
|
||||
``trio``'s cancellation system.
|
||||
|
||||
'''
|
||||
actor = current_actor()
|
||||
|
||||
# here we create a mem chan that corresponds to the
|
||||
# far end caller / callee.
|
||||
|
||||
# Likewise if the surrounding context has been cancelled we error here
|
||||
# since it likely means the surrounding block was exited or
|
||||
# killed
|
||||
|
||||
if self._cancel_called:
|
||||
task = trio.lowlevel.current_task().name
|
||||
raise ContextCancelled(
|
||||
f'Context around {actor.uid[0]}:{task} was already cancelled!'
|
||||
)
|
||||
|
||||
if not self._portal and not self._started_called:
|
||||
raise RuntimeError(
|
||||
'Context.started()` must be called before opening a stream'
|
||||
)
|
||||
|
||||
# NOTE: in one way streaming this only happens on the
|
||||
# caller side inside `Actor.start_remote_task()` so if you try
|
||||
# to send a stop from the caller to the callee in the
|
||||
# single-direction-stream case you'll get a lookup error
|
||||
# currently.
|
||||
ctx = actor.get_context(
|
||||
self.chan,
|
||||
self.cid,
|
||||
msg_buffer_size=msg_buffer_size,
|
||||
allow_overruns=allow_overruns,
|
||||
)
|
||||
ctx._allow_overruns = allow_overruns
|
||||
assert ctx is self
|
||||
|
||||
# XXX: If the underlying channel feeder receive mem chan has
|
||||
# been closed then likely client code has already exited
|
||||
# a ``.open_stream()`` block prior or there was some other
|
||||
# unanticipated error or cancellation from ``trio``.
|
||||
|
||||
if ctx._recv_chan._closed:
|
||||
raise trio.ClosedResourceError(
|
||||
'The underlying channel for this stream was already closed!?')
|
||||
|
||||
async with MsgStream(
|
||||
ctx=self,
|
||||
rx_chan=ctx._recv_chan,
|
||||
) as stream:
|
||||
|
||||
if self._portal:
|
||||
self._portal._streams.add(stream)
|
||||
|
||||
try:
|
||||
self._stream_opened = True
|
||||
|
||||
# XXX: do we need this?
|
||||
# ensure we aren't cancelled before yielding the stream
|
||||
# await trio.lowlevel.checkpoint()
|
||||
yield stream
|
||||
|
||||
# NOTE: Make the stream "one-shot use". On exit, signal
|
||||
# ``trio.EndOfChannel``/``StopAsyncIteration`` to the
|
||||
# far end.
|
||||
await stream.aclose()
|
||||
|
||||
finally:
|
||||
if self._portal:
|
||||
try:
|
||||
self._portal._streams.remove(stream)
|
||||
except KeyError:
|
||||
log.warning(
|
||||
f'Stream was already destroyed?\n'
|
||||
f'actor: {self.chan.uid}\n'
|
||||
f'ctx id: {self.cid}'
|
||||
)
|
||||
|
||||
def _maybe_raise_remote_err(
|
||||
self,
|
||||
err: Exception,
|
||||
) -> None:
|
||||
# NOTE: whenever the context's "opener" side (task) **is**
|
||||
# the side which requested the cancellation (likekly via
|
||||
# ``Context.cancel()``), we don't want to re-raise that
|
||||
# cancellation signal locally (would be akin to
|
||||
# a ``trio.Nursery`` nursery raising ``trio.Cancelled``
|
||||
# whenever ``CancelScope.cancel()`` was called) and instead
|
||||
# silently reap the expected cancellation "error"-msg.
|
||||
# if 'pikerd' in err.msgdata['tb_str']:
|
||||
# # from . import _debug
|
||||
# # await _debug.breakpoint()
|
||||
# breakpoint()
|
||||
|
||||
if (
|
||||
isinstance(err, ContextCancelled)
|
||||
and (
|
||||
self._cancel_called
|
||||
or self.chan._cancel_called
|
||||
or tuple(err.canceller) == current_actor().uid
|
||||
)
|
||||
):
|
||||
return err
|
||||
|
||||
raise err # from None
|
||||
|
||||
async def result(self) -> Any | Exception:
|
||||
'''
|
||||
From some (caller) side task, wait for and return the final
|
||||
result from the remote (callee) side's task.
|
||||
|
||||
This provides a mechanism for one task running in some actor to wait
|
||||
on another task at the other side, in some other actor, to terminate.
|
||||
|
||||
If the remote task is still in a streaming state (it is delivering
|
||||
values from inside a ``Context.open_stream():`` block, then those
|
||||
msgs are drained but discarded since it is presumed this side of
|
||||
the context has already finished with its own streaming logic.
|
||||
|
||||
If the remote context (or its containing actor runtime) was
|
||||
canceled, either by a local task calling one of
|
||||
``Context.cancel()`` or `Portal.cancel_actor()``, we ignore the
|
||||
received ``ContextCancelled`` exception if the context or
|
||||
underlying IPC channel is marked as having been "cancel called".
|
||||
This is similar behavior to using ``trio.Nursery.cancel()``
|
||||
wherein tasks which raise ``trio.Cancel`` are silently reaped;
|
||||
the main different in this API is in the "cancel called" case,
|
||||
instead of just not raising, we also return the exception *as
|
||||
the result* since client code may be interested in the details
|
||||
of the remote cancellation.
|
||||
|
||||
'''
|
||||
assert self._portal, "Context.result() can not be called from callee!"
|
||||
assert self._recv_chan
|
||||
|
||||
# from . import _debug
|
||||
# await _debug.breakpoint()
|
||||
|
||||
re = self._remote_error
|
||||
if re:
|
||||
self._maybe_raise_remote_err(re)
|
||||
return re
|
||||
|
||||
if (
|
||||
self._result == id(self)
|
||||
and not self._remote_error
|
||||
and not self._recv_chan._closed # type: ignore
|
||||
):
|
||||
# wait for a final context result consuming
|
||||
# and discarding any bi dir stream msgs still
|
||||
# in transit from the far end.
|
||||
while True:
|
||||
msg = await self._recv_chan.receive()
|
||||
try:
|
||||
self._result = msg['return']
|
||||
|
||||
# NOTE: we don't need to do this right?
|
||||
# XXX: only close the rx mem chan AFTER
|
||||
# a final result is retreived.
|
||||
# if self._recv_chan:
|
||||
# await self._recv_chan.aclose()
|
||||
|
||||
break
|
||||
except KeyError: # as msgerr:
|
||||
|
||||
if 'yield' in msg:
|
||||
# far end task is still streaming to us so discard
|
||||
log.warning(f'Discarding stream delivered {msg}')
|
||||
continue
|
||||
|
||||
elif 'stop' in msg:
|
||||
log.debug('Remote stream terminated')
|
||||
continue
|
||||
|
||||
# internal error should never get here
|
||||
assert msg.get('cid'), (
|
||||
"Received internal error at portal?")
|
||||
|
||||
err = unpack_error(
|
||||
msg,
|
||||
self._portal.channel
|
||||
) # from msgerr
|
||||
|
||||
err = self._maybe_raise_remote_err(err)
|
||||
self._remote_err = err
|
||||
|
||||
return self._remote_error or self._result
|
||||
|
||||
async def started(
|
||||
self,
|
||||
value: Any | None = None
|
||||
|
||||
) -> None:
|
||||
'''
|
||||
Indicate to calling actor's task that this linked context
|
||||
has started and send ``value`` to the other side.
|
||||
|
||||
On the calling side ``value`` is the second item delivered
|
||||
in the tuple returned by ``Portal.open_context()``.
|
||||
|
||||
'''
|
||||
if self._portal:
|
||||
raise RuntimeError(
|
||||
f"Caller side context {self} can not call started!")
|
||||
|
||||
elif self._started_called:
|
||||
raise RuntimeError(
|
||||
f"called 'started' twice on context with {self.chan.uid}")
|
||||
|
||||
await self.chan.send({'started': value, 'cid': self.cid})
|
||||
self._started_called = True
|
||||
|
||||
# TODO: do we need a restart api?
|
||||
# async def restart(self) -> None:
|
||||
# pass
|
||||
|
||||
async def _drain_overflows(
|
||||
self,
|
||||
) -> None:
|
||||
'''
|
||||
Private task spawned to push newly received msgs to the local
|
||||
task which getting overrun by the remote side.
|
||||
|
||||
In order to not block the rpc msg loop, but also not discard
|
||||
msgs received in this context, we need to async push msgs in
|
||||
a new task which only runs for as long as the local task is in
|
||||
an overrun state.
|
||||
|
||||
'''
|
||||
self._in_overrun = True
|
||||
try:
|
||||
while self._overflow_q:
|
||||
# NOTE: these msgs should never be errors since we always do
|
||||
# the check prior to checking if we're in an overrun state
|
||||
# inside ``.deliver_msg()``.
|
||||
msg = self._overflow_q.popleft()
|
||||
try:
|
||||
await self._send_chan.send(msg)
|
||||
except trio.BrokenResourceError:
|
||||
log.warning(
|
||||
f"{self._send_chan} consumer is already closed"
|
||||
)
|
||||
return
|
||||
except trio.Cancelled:
|
||||
# we are obviously still in overrun
|
||||
# but the context is being closed anyway
|
||||
# so we just warn that there are un received
|
||||
# msgs still..
|
||||
self._overflow_q.appendleft(msg)
|
||||
fmt_msgs = ''
|
||||
for msg in self._overflow_q:
|
||||
fmt_msgs += f'{pformat(msg)}\n'
|
||||
|
||||
log.warning(
|
||||
f'Context for {self.cid} is being closed while '
|
||||
'in an overrun state!\n'
|
||||
'Discarding the following msgs:\n'
|
||||
f'{fmt_msgs}\n'
|
||||
)
|
||||
raise
|
||||
|
||||
finally:
|
||||
# task is now finished with the backlog so mark us as
|
||||
# no longer in backlog.
|
||||
self._in_overrun = False
|
||||
|
||||
async def _deliver_msg(
|
||||
self,
|
||||
msg: dict,
|
||||
|
||||
draining: bool = False,
|
||||
|
||||
) -> bool:
|
||||
|
||||
cid = self.cid
|
||||
chan = self.chan
|
||||
uid = chan.uid
|
||||
send_chan: trio.MemorySendChannel = self._send_chan
|
||||
|
||||
log.runtime(
|
||||
f"Delivering {msg} from {uid} to caller {cid}"
|
||||
)
|
||||
|
||||
error = msg.get('error')
|
||||
if error:
|
||||
await self._maybe_cancel_and_set_remote_error(msg)
|
||||
|
||||
if (
|
||||
self._in_overrun
|
||||
):
|
||||
self._overflow_q.append(msg)
|
||||
return False
|
||||
|
||||
try:
|
||||
send_chan.send_nowait(msg)
|
||||
return True
|
||||
# if an error is deteced we should always
|
||||
# expect it to be raised by any context (stream)
|
||||
# consumer task
|
||||
|
||||
except trio.BrokenResourceError:
|
||||
# TODO: what is the right way to handle the case where the
|
||||
# local task has already sent a 'stop' / StopAsyncInteration
|
||||
# to the other side but and possibly has closed the local
|
||||
# feeder mem chan? Do we wait for some kind of ack or just
|
||||
# let this fail silently and bubble up (currently)?
|
||||
|
||||
# XXX: local consumer has closed their side
|
||||
# so cancel the far end streaming task
|
||||
log.warning(f"{send_chan} consumer is already closed")
|
||||
return False
|
||||
|
||||
# NOTE XXX: by default we do **not** maintain context-stream
|
||||
# backpressure and instead opt to relay stream overrun errors to
|
||||
# the sender; the main motivation is that using bp can block the
|
||||
# msg handling loop which calls into this method!
|
||||
except trio.WouldBlock:
|
||||
# XXX: always push an error even if the local
|
||||
# receiver is in overrun state.
|
||||
# await self._maybe_cancel_and_set_remote_error(msg)
|
||||
|
||||
local_uid = current_actor().uid
|
||||
lines = [
|
||||
f'OVERRUN on actor-task context {cid}@{local_uid}!\n'
|
||||
# TODO: put remote task name here if possible?
|
||||
f'remote sender actor: {uid}',
|
||||
# TODO: put task func name here and maybe an arrow
|
||||
# from sender to overrunner?
|
||||
# f'local task {self.func_name}'
|
||||
]
|
||||
if not self._stream_opened:
|
||||
lines.insert(
|
||||
1,
|
||||
f'\n*** No stream open on `{local_uid[0]}` side! ***\n'
|
||||
)
|
||||
|
||||
text = '\n'.join(lines)
|
||||
|
||||
# XXX: lul, this really can't be backpressure since any
|
||||
# blocking here will block the entire msg loop rpc sched for
|
||||
# a whole channel.. maybe we should rename it?
|
||||
if self._allow_overruns:
|
||||
text += f'\nStarting overflow queuing task on msg: {msg}'
|
||||
log.warning(text)
|
||||
if (
|
||||
not self._in_overrun
|
||||
):
|
||||
self._overflow_q.append(msg)
|
||||
n = self._scope_nursery
|
||||
assert not n.child_tasks
|
||||
try:
|
||||
n.start_soon(
|
||||
self._drain_overflows,
|
||||
)
|
||||
except RuntimeError:
|
||||
# if the nursery is already cancelled due to
|
||||
# this context exiting or in error, we ignore
|
||||
# the nursery error since we never expected
|
||||
# anything different.
|
||||
return False
|
||||
else:
|
||||
try:
|
||||
raise StreamOverrun(text)
|
||||
except StreamOverrun as err:
|
||||
err_msg = pack_error(err)
|
||||
err_msg['cid'] = cid
|
||||
try:
|
||||
await chan.send(err_msg)
|
||||
except trio.BrokenResourceError:
|
||||
# XXX: local consumer has closed their side
|
||||
# so cancel the far end streaming task
|
||||
log.warning(f"{chan} is already closed")
|
||||
|
||||
return False
|
||||
|
||||
|
||||
def mk_context(
|
||||
chan: Channel,
|
||||
cid: str,
|
||||
msg_buffer_size: int = 2**6,
|
||||
|
||||
**kwargs,
|
||||
|
||||
) -> Context:
|
||||
'''
|
||||
Internal factory to create an inter-actor task ``Context``.
|
||||
|
||||
This is called by internals and should generally never be called
|
||||
by user code.
|
||||
|
||||
'''
|
||||
send_chan: trio.MemorySendChannel
|
||||
recv_chan: trio.MemoryReceiveChannel
|
||||
send_chan, recv_chan = trio.open_memory_channel(msg_buffer_size)
|
||||
|
||||
ctx = Context(
|
||||
chan,
|
||||
cid,
|
||||
_send_chan=send_chan,
|
||||
_recv_chan=recv_chan,
|
||||
**kwargs,
|
||||
)
|
||||
ctx._result = id(ctx)
|
||||
return ctx
|
||||
|
||||
|
||||
def stream(func: Callable) -> Callable:
|
||||
'''
|
||||
Mark an async function as a streaming routine with ``@stream``.
|
||||
|
|
@ -1078,22 +379,3 @@ def stream(func: Callable) -> Callable:
|
|||
"(Or ``to_trio`` if using ``asyncio`` in guest mode)."
|
||||
)
|
||||
return func
|
||||
|
||||
|
||||
def context(func: Callable) -> Callable:
|
||||
'''
|
||||
Mark an async function as a streaming routine with ``@context``.
|
||||
|
||||
'''
|
||||
# TODO: apply whatever solution ``mypy`` ends up picking for this:
|
||||
# https://github.com/python/mypy/issues/2087#issuecomment-769266912
|
||||
func._tractor_context_function = True # type: ignore
|
||||
|
||||
sig = inspect.signature(func)
|
||||
params = sig.parameters
|
||||
if 'ctx' not in params:
|
||||
raise TypeError(
|
||||
"The first argument to the context function "
|
||||
f"{func.__name__} must be `ctx: tractor.Context`"
|
||||
)
|
||||
return func
|
||||
|
|
|
|||
|
|
@ -37,7 +37,7 @@ import trio
|
|||
import wrapt
|
||||
|
||||
from ..log import get_logger
|
||||
from .._streaming import Context
|
||||
from .._context import Context
|
||||
|
||||
|
||||
__all__ = ['pub']
|
||||
|
|
@ -148,7 +148,8 @@ def pub(
|
|||
*,
|
||||
tasks: set[str] = set(),
|
||||
):
|
||||
"""Publisher async generator decorator.
|
||||
'''
|
||||
Publisher async generator decorator.
|
||||
|
||||
A publisher can be called multiple times from different actors but
|
||||
will only spawn a finite set of internal tasks to stream values to
|
||||
|
|
@ -227,7 +228,8 @@ def pub(
|
|||
running in a single actor to stream data to an arbitrary number of
|
||||
subscribers. If you are ok to have a new task running for every call
|
||||
to ``pub_service()`` then probably don't need this.
|
||||
"""
|
||||
|
||||
'''
|
||||
global _pubtask2lock
|
||||
|
||||
# handle the decorator not called with () case
|
||||
|
|
|
|||
Loading…
Reference in New Issue