Drop the "main" task via kwarg idea
Stop worrying about a "main task" in each actor and instead add an
additional `ActorNursery.run_in_actor()` method which wraps calls
to create an actor and run a lone RPC task inside it. Note this
adjusts the public API of `ActorNursery.start_actor()` to drop
its `main` kwarg.
The dirty deats of making this possible:
- each spawned RPC task is now tracked with a specific cancel scope such
that when the actor is cancelled all ongoing responders are cancelled
before any IPC/channel machinery is closed (turns out that spawning
new actors from `outlive_main=True` actors was probably borked before
finally getting this working).
- make each initial RPC response be a packet which describes the
`functype` (eg. `{'functype': 'asyncfunction'}`) allowing for async
calls/submissions by client actors (this was required to make
`run_in_actor()` work - `Portal._submit()` is the new async method).
- hooray we can stop faking "main task" results for daemon actors
- add better handling/raising of internal errors caught in the bowels of
the `Actor` itself.
- drop the rpc spawning nursery; just use the `Actor._root_nursery`
- only wait on `_no_more_peers` if there are existing peer channels that
are actually still connected.
- an `ActorNursery.__aexit__()` now implicitly waits on `Portal.result()` on close
for each `run_in_actor()` spawned actor.
- handle cancelling partial started actors which haven't yet connected
back to the parent
Resolves #24
drop_main_kwarg
Tyler Goodlet
parent
f726bd81da
commit
bb13b79df5
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@ -49,23 +49,22 @@ async def _main(async_fn, args, kwargs, name, arbiter_addr):
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log.info(f"Arbiter seems to exist @ {host}:{port}")
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actor = Actor(
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name or 'anonymous',
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main=main,
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arbiter_addr=arbiter_addr,
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**kwargs
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)
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host, port = (host, 0)
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else:
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# start this local actor as the arbiter
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# this should eventually get passed `outlive_main=True`?
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actor = Arbiter(
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name or 'arbiter', main=main, arbiter_addr=arbiter_addr, **kwargs)
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name or 'arbiter', arbiter_addr=arbiter_addr, **kwargs)
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# ``Actor._async_main()`` creates an internal nursery if one is not
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# provided and thus blocks here until it's main task completes.
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# Note that if the current actor is the arbiter it is desirable
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# for it to stay up indefinitely until a re-election process has
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# taken place - which is not implemented yet FYI).
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return await _start_actor(actor, host, port, arbiter_addr=arbiter_addr)
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return await _start_actor(
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actor, main, host, port, arbiter_addr=arbiter_addr)
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def run(
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@ -5,9 +5,9 @@ import inspect
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import importlib
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from collections import defaultdict
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from functools import partial
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from typing import Coroutine
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import traceback
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import uuid
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from itertools import chain
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import trio
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from async_generator import asynccontextmanager, aclosing
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@ -27,9 +27,13 @@ class ActorFailure(Exception):
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"General actor failure"
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class InternalActorError(RuntimeError):
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"Actor primitive internals failure"
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async def _invoke(
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cid, chan, func, kwargs,
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treat_as_gen=False, raise_errs=False,
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actor, cid, chan, func, kwargs,
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treat_as_gen=False,
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task_status=trio.TASK_STATUS_IGNORED
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):
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"""Invoke local func and return results over provided channel.
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@ -47,11 +51,15 @@ async def _invoke(
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not is_async_partial and
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not is_async_gen_partial
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):
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await chan.send({'return': func(**kwargs), 'cid': cid})
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await chan.send({'functype': 'function', 'cid': cid})
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with trio.open_cancel_scope() as cs:
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task_status.started(cs)
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await chan.send({'return': func(**kwargs), 'cid': cid})
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else:
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coro = func(**kwargs)
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if inspect.isasyncgen(coro):
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await chan.send({'functype': 'asyncgen', 'cid': cid})
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# XXX: massive gotcha! If the containing scope
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# is cancelled and we execute the below line,
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# any ``ActorNursery.__aexit__()`` WON'T be
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@ -59,40 +67,55 @@ async def _invoke(
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# have to properly handle the closing (aclosing)
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# of the async gen in order to be sure the cancel
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# is propagated!
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async with aclosing(coro) as agen:
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async for item in agen:
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# TODO: can we send values back in here?
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# it's gonna require a `while True:` and
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# some non-blocking way to retrieve new `asend()`
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# values from the channel:
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# to_send = await chan.recv_nowait()
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# if to_send is not None:
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# to_yield = await coro.asend(to_send)
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await chan.send({'yield': item, 'cid': cid})
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with trio.open_cancel_scope() as cs:
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task_status.started(cs)
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async with aclosing(coro) as agen:
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async for item in agen:
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# TODO: can we send values back in here?
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# it's gonna require a `while True:` and
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# some non-blocking way to retrieve new `asend()`
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# values from the channel:
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# to_send = await chan.recv_nowait()
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# if to_send is not None:
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# to_yield = await coro.asend(to_send)
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await chan.send({'yield': item, 'cid': cid})
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log.debug(f"Finished iterating {coro}")
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# TODO: we should really support a proper
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# `StopAsyncIteration` system here for returning a final
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# value if desired
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await chan.send({'stop': None, 'cid': cid})
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log.debug(f"Finished iterating {coro}")
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# TODO: we should really support a proper
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# `StopAsyncIteration` system here for returning a final
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# value if desired
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await chan.send({'stop': None, 'cid': cid})
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else:
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if treat_as_gen:
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await chan.send({'functype': 'asyncgen', 'cid': cid})
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# XXX: the async-func may spawn further tasks which push
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# back values like an async-generator would but must
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# manualy construct the response dict-packet-responses as
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# above
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await coro
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with trio.open_cancel_scope() as cs:
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task_status.started(cs)
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await coro
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else:
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await chan.send({'return': await coro, 'cid': cid})
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await chan.send({'functype': 'asyncfunction', 'cid': cid})
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with trio.open_cancel_scope() as cs:
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task_status.started(cs)
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await chan.send({'return': await coro, 'cid': cid})
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except Exception:
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# always ship errors back to caller
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log.exception("Actor errored:")
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if not raise_errs:
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await chan.send({'error': traceback.format_exc(), 'cid': cid})
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else:
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raise
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await chan.send({'error': traceback.format_exc(), 'cid': cid})
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finally:
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# RPC task bookeeping
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tasks = actor._rpc_tasks.get(chan, None)
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if tasks:
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tasks.remove((cs, func))
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task_status.started()
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if not tasks:
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actor._rpc_tasks.pop(chan, None)
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if not actor._rpc_tasks:
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log.info(f"All RPC tasks have completed")
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actor._no_more_rpc_tasks.set()
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class Actor:
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@ -108,12 +131,10 @@ class Actor:
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def __init__(
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self,
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name: str,
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main: Coroutine = None,
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rpc_module_paths: [str] = [],
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statespace: dict = {},
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uid: str = None,
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allow_rpc: bool = True,
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outlive_main: bool = False,
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loglevel: str = None,
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arbiter_addr: (str, int) = None,
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):
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@ -121,22 +142,25 @@ class Actor:
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self.uid = (name, uid or str(uuid.uuid1()))
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self.rpc_module_paths = rpc_module_paths
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self._mods = {}
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self.main = main
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# TODO: consider making this a dynamically defined
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# @dataclass once we get py3.7
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self.statespace = statespace
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self._allow_rpc = allow_rpc
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self._outlive_main = outlive_main
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self.loglevel = loglevel
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self._arb_addr = arbiter_addr
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# filled in by `_async_main` after fork
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self._root_nursery = None
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self._server_nursery = None
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self._peers = defaultdict(list)
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self._peer_connected = {}
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self._no_more_peers = trio.Event()
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self._main_complete = trio.Event()
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self._main_scope = None
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self._no_more_peers.set()
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self._no_more_rpc_tasks = trio.Event()
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self._no_more_rpc_tasks.set()
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self._rpc_tasks = {}
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self._actors2calls = {} # map {uids -> {callids -> waiter queues}}
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self._listeners = []
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self._parent_chan = None
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@ -209,12 +233,6 @@ class Actor:
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if not chans:
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log.debug(f"No more channels for {chan.uid}")
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self._peers.pop(chan.uid, None)
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if not self._actors2calls.get(chan.uid, {}).get('main'):
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# fake a "main task" result for any waiting
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# nurseries/portals
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log.debug(f"Faking result for {chan} from {chan.uid}")
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q = self.get_waitq(chan.uid, 'main')
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q.put_nowait({'return': None, 'cid': 'main'})
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log.debug(f"Peers is {self._peers}")
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@ -222,7 +240,7 @@ class Actor:
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self._no_more_peers.set()
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log.debug(f"Signalling no more peer channels")
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# XXX: is this necessary?
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# # XXX: is this necessary (GC should do it?)
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if chan.connected():
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log.debug(f"Disconnecting channel {chan}")
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await chan.send(None)
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@ -259,63 +277,91 @@ class Actor:
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# TODO: once https://github.com/python-trio/trio/issues/467 gets
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# worked out we'll likely want to use that!
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log.debug(f"Entering msg loop for {chan} from {chan.uid}")
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async with trio.open_nursery() as nursery:
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try:
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async for msg in chan.aiter_recv():
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if msg is None: # terminate sentinel
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log.debug(
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f"Cancelling all tasks for {chan} from {chan.uid}")
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nursery.cancel_scope.cancel()
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log.debug(
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f"Msg loop signalled to terminate for"
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f" {chan} from {chan.uid}")
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break
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log.debug(f"Received msg {msg} from {chan.uid}")
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cid = msg.get('cid')
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if cid: # deliver response to local caller/waiter
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await self._push_result(chan.uid, cid, msg)
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log.debug(
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f"Waiting on next msg for {chan} from {chan.uid}")
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continue
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else:
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ns, funcname, kwargs, actorid, cid = msg['cmd']
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try:
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async for msg in chan.aiter_recv():
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if msg is None: # terminate sentinel
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log.debug(
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f"Cancelling all tasks for {chan} from {chan.uid}")
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scopes = self._rpc_tasks.pop(chan, None)
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if scopes:
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for scope, func in scopes:
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scope.cancel()
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log.debug(
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f"Processing request from {actorid}\n"
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f"{ns}.{funcname}({kwargs})")
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if ns == 'self':
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func = getattr(self, funcname)
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else:
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func = getattr(self._mods[ns], funcname)
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f"Msg loop signalled to terminate for"
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f" {chan} from {chan.uid}")
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break
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log.debug(f"Received msg {msg} from {chan.uid}")
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cid = msg.get('cid')
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if cid:
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if cid == 'internal': # internal actor error
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# import pdb; pdb.set_trace()
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raise InternalActorError(
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f"{chan.uid}\n" + msg['error'])
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# spin up a task for the requested function
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sig = inspect.signature(func)
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treat_as_gen = False
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if 'chan' in sig.parameters:
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assert 'cid' in sig.parameters, \
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f"{func} must accept a `cid` (caller id) kwarg"
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kwargs['chan'] = chan
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kwargs['cid'] = cid
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# TODO: eventually we want to be more stringent
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# about what is considered a far-end async-generator.
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# Right now both actual async gens and any async
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# function which declares a `chan` kwarg in its
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# signature will be treated as one.
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treat_as_gen = True
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log.debug(f"Spawning task for {func}")
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nursery.start_soon(
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_invoke, cid, chan, func, kwargs, treat_as_gen,
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name=funcname
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)
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# deliver response to local caller/waiter
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await self._push_result(chan.uid, cid, msg)
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log.debug(
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f"Waiting on next msg for {chan} from {chan.uid}")
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else: # channel disconnect
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log.debug(f"{chan} from {chan.uid} disconnected")
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except trio.ClosedStreamError:
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log.error(f"{chan} form {chan.uid} broke")
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continue
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log.debug(f"Exiting msg loop for {chan} from {chan.uid}")
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# process command request
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ns, funcname, kwargs, actorid, cid = msg['cmd']
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log.debug(
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f"Processing request from {actorid}\n"
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f"{ns}.{funcname}({kwargs})")
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if ns == 'self':
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func = getattr(self, funcname)
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else:
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func = getattr(self._mods[ns], funcname)
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# spin up a task for the requested function
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sig = inspect.signature(func)
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treat_as_gen = False
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if 'chan' in sig.parameters:
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assert 'cid' in sig.parameters, \
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f"{func} must accept a `cid` (caller id) kwarg"
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kwargs['chan'] = chan
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kwargs['cid'] = cid
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# TODO: eventually we want to be more stringent
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# about what is considered a far-end async-generator.
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# Right now both actual async gens and any async
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# function which declares a `chan` kwarg in its
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# signature will be treated as one.
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treat_as_gen = True
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log.debug(f"Spawning task for {func}")
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cs = await self._root_nursery.start(
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_invoke, self, cid, chan, func, kwargs, treat_as_gen,
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name=funcname
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)
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# never allow cancelling cancel requests (results in
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# deadlock and other weird behaviour)
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if func != self.cancel:
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self._no_more_rpc_tasks.clear()
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log.info(f"RPC func is {func}")
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self._rpc_tasks.setdefault(chan, []).append((cs, func))
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log.debug(
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f"Waiting on next msg for {chan} from {chan.uid}")
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else: # channel disconnect
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log.debug(f"{chan} from {chan.uid} disconnected")
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except InternalActorError:
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# ship internal errors upwards
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if self._parent_chan:
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await self._parent_chan.send(
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{'error': traceback.format_exc(), 'cid': 'internal'})
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raise
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except trio.ClosedResourceError:
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log.error(f"{chan} form {chan.uid} broke")
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except Exception:
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# ship exception (from above code) to peer as an internal error
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await chan.send(
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{'error': traceback.format_exc(), 'cid': 'internal'})
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raise
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finally:
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log.debug(f"Exiting msg loop for {chan} from {chan.uid}")
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def _fork_main(self, accept_addr, parent_addr=None):
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# after fork routine which invokes a fresh ``trio.run``
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@ -324,7 +370,7 @@ class Actor:
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if self.loglevel is not None:
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get_console_log(self.loglevel)
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log.info(
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f"Started new {ctx.current_process()} for actor {self.uid}")
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f"Started new {ctx.current_process()} for {self.uid}")
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_state._current_actor = self
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log.debug(f"parent_addr is {parent_addr}")
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try:
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@ -332,14 +378,15 @@ class Actor:
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self._async_main, accept_addr, parent_addr=parent_addr))
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except KeyboardInterrupt:
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pass # handle it the same way trio does?
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log.debug(f"Actor {self.uid} terminated")
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log.info(f"Actor {self.uid} terminated")
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async def _async_main(
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self,
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accept_addr,
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arbiter_addr=None,
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parent_addr=None,
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nursery=None
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nursery=None,
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task_status=trio.TASK_STATUS_IGNORED,
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):
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"""Start the channel server, maybe connect back to the parent, and
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start the main task.
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|
|
@ -347,7 +394,6 @@ class Actor:
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A "root-most" (or "top-level") nursery for this actor is opened here
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and when cancelled effectively cancels the actor.
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"""
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result = None
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arbiter_addr = arbiter_addr or self._arb_addr
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registered_with_arbiter = False
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try:
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|
@ -373,7 +419,6 @@ class Actor:
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# exception back to the parent actor)
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chan = self._parent_chan = Channel(
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destaddr=parent_addr,
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on_reconnect=self.main
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)
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await chan.connect()
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# initial handshake, report who we are, who they are
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|
|
@ -382,7 +427,7 @@ class Actor:
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log.warn(
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f"Failed to connect to parent @ {parent_addr},"
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" closing server")
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self.cancel_server()
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await self.cancel()
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self._parent_chan = None
|
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# register with the arbiter if we're told its addr
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|
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@ -393,6 +438,7 @@ class Actor:
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name=self.name, sockaddr=self.accept_addr)
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registered_with_arbiter = True
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task_status.started()
|
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# handle new connection back to parent optionally
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# begin responding to RPC
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if self._allow_rpc:
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|
|
@ -401,38 +447,6 @@ class Actor:
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nursery.start_soon(
|
||||
self._process_messages, self._parent_chan)
|
||||
|
||||
if self.main:
|
||||
try:
|
||||
if self._parent_chan:
|
||||
async with trio.open_nursery() as n:
|
||||
self._main_scope = n.cancel_scope
|
||||
log.debug(f"Starting main task `{self.main}`")
|
||||
# spawned subactor so deliver "main"
|
||||
# task result(s) back to parent
|
||||
await n.start(
|
||||
_invoke, 'main',
|
||||
self._parent_chan, self.main, {},
|
||||
# treat_as_gen, raise_errs params
|
||||
False, True
|
||||
)
|
||||
else:
|
||||
with trio.open_cancel_scope() as main_scope:
|
||||
self._main_scope = main_scope
|
||||
# run directly we are an "unspawned actor"
|
||||
log.debug(f"Running `{self.main}` directly")
|
||||
result = await self.main()
|
||||
finally:
|
||||
# tear down channel server in order to ensure
|
||||
# we exit normally when the main task is done
|
||||
if not self._outlive_main:
|
||||
log.debug(f"Shutting down channel server")
|
||||
self.cancel_server()
|
||||
log.debug(f"Shutting down root nursery")
|
||||
nursery.cancel_scope.cancel()
|
||||
self._main_complete.set()
|
||||
|
||||
if self._main_scope.cancelled_caught:
|
||||
log.debug("Main task was cancelled sucessfully")
|
||||
log.debug("Waiting on root nursery to complete")
|
||||
# blocks here as expected if no nursery was provided until
|
||||
# the channel server is killed (i.e. this actor is
|
||||
|
|
@ -441,7 +455,7 @@ class Actor:
|
|||
if self._parent_chan:
|
||||
try:
|
||||
await self._parent_chan.send(
|
||||
{'error': traceback.format_exc(), 'cid': 'main'})
|
||||
{'error': traceback.format_exc(), 'cid': 'internal'})
|
||||
except trio.ClosedStreamError:
|
||||
log.error(
|
||||
f"Failed to ship error to parent "
|
||||
|
|
@ -458,18 +472,18 @@ class Actor:
|
|||
# terminate actor once all it's peers (actors that connected
|
||||
# to it as clients) have disappeared
|
||||
if not self._no_more_peers.is_set():
|
||||
log.debug(
|
||||
f"Waiting for remaining peers {self._peers} to clear")
|
||||
await self._no_more_peers.wait()
|
||||
if any(
|
||||
chan.connected() for chan in chain(*self._peers.values())
|
||||
):
|
||||
log.debug(
|
||||
f"Waiting for remaining peers {self._peers} to clear")
|
||||
await self._no_more_peers.wait()
|
||||
log.debug(f"All peer channels are complete")
|
||||
|
||||
# tear down channel server no matter what since we errored
|
||||
# or completed
|
||||
log.debug(f"Shutting down channel server")
|
||||
self.cancel_server()
|
||||
|
||||
return result
|
||||
|
||||
async def _serve_forever(
|
||||
self,
|
||||
*,
|
||||
|
|
@ -514,20 +528,39 @@ class Actor:
|
|||
log.warn(f"Unable to unregister {self.name} from arbiter")
|
||||
|
||||
async def cancel(self):
|
||||
"""This cancels the internal root-most nursery thereby gracefully
|
||||
cancelling (for all intents and purposes) this actor.
|
||||
"""Cancel this actor.
|
||||
|
||||
The sequence in order is:
|
||||
- cancelling all rpc tasks
|
||||
- cancelling the channel server
|
||||
- cancel the "root" nursery
|
||||
"""
|
||||
# cancel all ongoing rpc tasks
|
||||
await self.cancel_rpc_tasks()
|
||||
self.cancel_server()
|
||||
if self._main_scope:
|
||||
self._main_scope.cancel()
|
||||
log.debug("Waiting on main task to complete")
|
||||
await self._main_complete.wait()
|
||||
self._root_nursery.cancel_scope.cancel()
|
||||
|
||||
async def cancel_rpc_tasks(self):
|
||||
"""Cancel all existing RPC responder tasks using the cancel scope
|
||||
registered for each.
|
||||
"""
|
||||
scopes = self._rpc_tasks
|
||||
log.info(f"Cancelling all {len(scopes)} rpc tasks:\n{scopes}")
|
||||
for chan, scopes in scopes.items():
|
||||
log.debug(f"Cancelling all tasks for {chan.uid}")
|
||||
for scope, func in scopes:
|
||||
log.debug(f"Cancelling task for {func}")
|
||||
scope.cancel()
|
||||
if scopes:
|
||||
log.info(
|
||||
f"Waiting for remaining rpc tasks to complete {scopes}")
|
||||
await self._no_more_rpc_tasks.wait()
|
||||
|
||||
def cancel_server(self):
|
||||
"""Cancel the internal channel server nursery thereby
|
||||
preventing any new inbound connections from being established.
|
||||
"""
|
||||
log.debug("Shutting down channel server")
|
||||
self._server_nursery.cancel_scope.cancel()
|
||||
|
||||
@property
|
||||
|
|
@ -568,7 +601,7 @@ class Arbiter(Actor):
|
|||
self._registry.pop(name, None)
|
||||
|
||||
|
||||
async def _start_actor(actor, host, port, arbiter_addr, nursery=None):
|
||||
async def _start_actor(actor, main, host, port, arbiter_addr, nursery=None):
|
||||
"""Spawn a local actor by starting a task to execute it's main
|
||||
async function.
|
||||
|
||||
|
|
@ -582,16 +615,19 @@ async def _start_actor(actor, host, port, arbiter_addr, nursery=None):
|
|||
# NOTE: this won't block since we provide the nursery
|
||||
log.info(f"Starting local {actor} @ {host}:{port}")
|
||||
|
||||
result = await actor._async_main(
|
||||
accept_addr=(host, port),
|
||||
parent_addr=None,
|
||||
arbiter_addr=arbiter_addr,
|
||||
nursery=nursery,
|
||||
)
|
||||
# XXX: If spawned locally, the actor is cancelled when this
|
||||
# context is complete given that there are no more active
|
||||
# peer channels connected to it.
|
||||
if not actor._outlive_main:
|
||||
async with trio.open_nursery() as nursery:
|
||||
await nursery.start(
|
||||
partial(
|
||||
actor._async_main,
|
||||
accept_addr=(host, port),
|
||||
parent_addr=None,
|
||||
arbiter_addr=arbiter_addr,
|
||||
)
|
||||
)
|
||||
result = await main()
|
||||
# XXX: If spawned locally, the actor is cancelled when this
|
||||
# context is complete given that there are no more active
|
||||
# peer channels connected to it.
|
||||
actor.cancel_server()
|
||||
|
||||
# unset module state
|
||||
|
|
|
|||
|
|
@ -42,20 +42,6 @@ async def _do_handshake(actor, chan):
|
|||
return uid
|
||||
|
||||
|
||||
async def result_from_q(q, chan):
|
||||
"""Process a msg from a remote actor.
|
||||
"""
|
||||
first_msg = await q.get()
|
||||
if 'return' in first_msg:
|
||||
return 'return', first_msg, q
|
||||
elif 'yield' in first_msg:
|
||||
return 'yield', first_msg, q
|
||||
elif 'error' in first_msg:
|
||||
raise RemoteActorError(f"{chan.uid}\n" + first_msg['error'])
|
||||
else:
|
||||
raise ValueError(f"{first_msg} is an invalid response packet?")
|
||||
|
||||
|
||||
class Portal:
|
||||
"""A 'portal' to a(n) (remote) ``Actor``.
|
||||
|
||||
|
|
@ -67,7 +53,12 @@ class Portal:
|
|||
"""
|
||||
def __init__(self, channel):
|
||||
self.channel = channel
|
||||
# when this is set to a tuple returned from ``_submit()`` then
|
||||
# it is expected that ``result()`` will be awaited at some point
|
||||
# during the portal's lifetime
|
||||
self._result = None
|
||||
self._expect_result = None
|
||||
self._errored = False
|
||||
|
||||
async def aclose(self):
|
||||
log.debug(f"Closing {self}")
|
||||
|
|
@ -75,26 +66,56 @@ class Portal:
|
|||
# gets in!
|
||||
await self.channel.aclose()
|
||||
|
||||
async def run(self, ns, func, **kwargs):
|
||||
"""Submit a function to be scheduled and run by actor, return its
|
||||
(stream of) result(s).
|
||||
async def _submit(self, ns, func, **kwargs):
|
||||
"""Submit a function to be scheduled and run by actor, return the
|
||||
associated caller id, response queue, response type str,
|
||||
first message packet as a tuple.
|
||||
|
||||
This is an async call.
|
||||
"""
|
||||
# ship a function call request to the remote actor
|
||||
cid, q = await current_actor().send_cmd(self.channel, ns, func, kwargs)
|
||||
|
||||
# wait on first response msg and handle (this should be
|
||||
# in an immediate response)
|
||||
first_msg = await q.get()
|
||||
functype = first_msg.get('functype')
|
||||
|
||||
if functype == 'function' or functype == 'asyncfunction':
|
||||
resp_type = 'return'
|
||||
elif functype == 'asyncgen':
|
||||
resp_type = 'yield'
|
||||
elif 'error' in first_msg:
|
||||
raise RemoteActorError(
|
||||
f"{self.channel.uid}\n" + first_msg['error'])
|
||||
else:
|
||||
raise ValueError(f"{first_msg} is an invalid response packet?")
|
||||
|
||||
return cid, q, resp_type, first_msg
|
||||
|
||||
async def _submit_for_result(self, ns, func, **kwargs):
|
||||
assert self._expect_result is None, \
|
||||
"A pending main result has already been submitted"
|
||||
self._expect_result = await self._submit(ns, func, **kwargs)
|
||||
|
||||
async def run(self, ns, func, **kwargs):
|
||||
"""Submit a function to be scheduled and run by actor, wrap and return
|
||||
its (stream of) result(s).
|
||||
|
||||
This is a blocking call.
|
||||
"""
|
||||
return await self._return_from_resptype(
|
||||
*(await self._submit(ns, func, **kwargs))
|
||||
)
|
||||
|
||||
async def _return_from_resptype(self, cid, q, resptype, first_msg):
|
||||
# TODO: not this needs some serious work and thinking about how
|
||||
# to make async-generators the fundamental IPC API over channels!
|
||||
# (think `yield from`, `gen.send()`, and functional reactive stuff)
|
||||
actor = current_actor()
|
||||
# ship a function call request to the remote actor
|
||||
cid, q = await actor.send_cmd(self.channel, ns, func, kwargs)
|
||||
# wait on first response msg and handle
|
||||
return await self._return_from_resptype(
|
||||
cid, *(await result_from_q(q, self.channel)))
|
||||
|
||||
async def _return_from_resptype(self, cid, resptype, first_msg, q):
|
||||
|
||||
if resptype == 'yield':
|
||||
|
||||
async def yield_from_q():
|
||||
yield first_msg['yield']
|
||||
try:
|
||||
async for msg in q:
|
||||
try:
|
||||
|
|
@ -103,8 +124,9 @@ class Portal:
|
|||
if 'stop' in msg:
|
||||
break # far end async gen terminated
|
||||
else:
|
||||
raise RemoteActorError(msg['error'])
|
||||
except GeneratorExit:
|
||||
raise RemoteActorError(
|
||||
f"{self.channel.uid}\n" + msg['error'])
|
||||
except StopAsyncIteration:
|
||||
log.debug(
|
||||
f"Cancelling async gen call {cid} to "
|
||||
f"{self.channel.uid}")
|
||||
|
|
@ -113,22 +135,24 @@ class Portal:
|
|||
return yield_from_q()
|
||||
|
||||
elif resptype == 'return':
|
||||
return first_msg['return']
|
||||
msg = await q.get()
|
||||
try:
|
||||
return msg['return']
|
||||
except KeyError:
|
||||
raise RemoteActorError(
|
||||
f"{self.channel.uid}\n" + msg['error'])
|
||||
else:
|
||||
raise ValueError(f"Unknown msg response type: {first_msg}")
|
||||
|
||||
async def result(self):
|
||||
"""Return the result(s) from the remote actor's "main" task.
|
||||
"""
|
||||
if self._result is None:
|
||||
q = current_actor().get_waitq(self.channel.uid, 'main')
|
||||
resptype, first_msg, q = (await result_from_q(q, self.channel))
|
||||
if self._expect_result is None:
|
||||
raise RuntimeError("This portal is not expecting a final result?")
|
||||
elif self._result is None:
|
||||
self._result = await self._return_from_resptype(
|
||||
'main', resptype, first_msg, q)
|
||||
log.warn(
|
||||
f"Retrieved first result `{self._result}` "
|
||||
f"for {self.channel.uid}")
|
||||
# await q.put(first_msg) # for next consumer (e.g. nursery)
|
||||
*self._expect_result
|
||||
)
|
||||
return self._result
|
||||
|
||||
async def close(self):
|
||||
|
|
@ -153,7 +177,9 @@ class Portal:
|
|||
log.warn(
|
||||
f"{self.channel} for {self.channel.uid} was already closed?")
|
||||
return False
|
||||
|
||||
else:
|
||||
log.warn(f"May have failed to cancel {self.channel.uid}")
|
||||
return False
|
||||
|
||||
class LocalPortal:
|
||||
"""A 'portal' to a local ``Actor``.
|
||||
|
|
|
|||
|
|
@ -2,9 +2,10 @@
|
|||
``trio`` inspired apis and helpers
|
||||
"""
|
||||
import multiprocessing as mp
|
||||
import inspect
|
||||
|
||||
import trio
|
||||
from async_generator import asynccontextmanager
|
||||
from async_generator import asynccontextmanager, aclosing
|
||||
|
||||
from ._state import current_actor
|
||||
from .log import get_logger, get_loglevel
|
||||
|
|
@ -22,9 +23,9 @@ class ActorNursery:
|
|||
def __init__(self, actor, supervisor=None):
|
||||
self.supervisor = supervisor # TODO
|
||||
self._actor = actor
|
||||
# We'll likely want some way to cancel all sub-actors eventually
|
||||
# self.cancel_scope = cancel_scope
|
||||
self._children = {}
|
||||
# portals spawned with ``run_in_actor()``
|
||||
self._cancel_after_result_on_exit = set()
|
||||
self.cancelled = False
|
||||
|
||||
async def __aenter__(self):
|
||||
|
|
@ -33,11 +34,9 @@ class ActorNursery:
|
|||
async def start_actor(
|
||||
self,
|
||||
name: str,
|
||||
main=None,
|
||||
bind_addr=('127.0.0.1', 0),
|
||||
statespace=None,
|
||||
rpc_module_paths=None,
|
||||
outlive_main=False, # sub-actors die when their main task completes
|
||||
loglevel=None, # set log level per subactor
|
||||
):
|
||||
loglevel = loglevel or self._actor.loglevel or get_loglevel()
|
||||
|
|
@ -46,8 +45,6 @@ class ActorNursery:
|
|||
# modules allowed to invoked funcs from
|
||||
rpc_module_paths=rpc_module_paths or [],
|
||||
statespace=statespace, # global proc state vars
|
||||
main=main, # main coroutine to be invoked
|
||||
outlive_main=outlive_main,
|
||||
loglevel=loglevel,
|
||||
arbiter_addr=current_actor()._arb_addr,
|
||||
)
|
||||
|
|
@ -59,6 +56,11 @@ class ActorNursery:
|
|||
# daemon=True,
|
||||
name=name,
|
||||
)
|
||||
# register the process before start in case we get a cancel
|
||||
# request before the actor has fully spawned - then we can wait
|
||||
# for it to fully come up before sending a cancel request
|
||||
self._children[actor.uid] = [actor, proc, None]
|
||||
|
||||
proc.start()
|
||||
if not proc.is_alive():
|
||||
raise ActorFailure("Couldn't start sub-actor?")
|
||||
|
|
@ -69,7 +71,39 @@ class ActorNursery:
|
|||
# local actor by the time we get a ref to it
|
||||
event, chan = await self._actor.wait_for_peer(actor.uid)
|
||||
portal = Portal(chan)
|
||||
self._children[(name, proc.pid)] = (actor, proc, portal)
|
||||
self._children[actor.uid][2] = portal
|
||||
return portal
|
||||
|
||||
async def run_in_actor(
|
||||
self,
|
||||
name,
|
||||
fn,
|
||||
bind_addr=('127.0.0.1', 0),
|
||||
rpc_module_paths=None,
|
||||
statespace=None,
|
||||
loglevel=None, # set log level per subactor
|
||||
**kwargs, # explicit args to ``fn``
|
||||
):
|
||||
"""Spawn a new actor, run a lone task, then terminate the actor and
|
||||
return its result.
|
||||
|
||||
Actors spawned using this method are kept alive at nursery teardown
|
||||
until the task spawned by executing ``fn`` completes at which point
|
||||
the actor is terminated.
|
||||
"""
|
||||
mod_path = fn.__module__
|
||||
portal = await self.start_actor(
|
||||
name,
|
||||
rpc_module_paths=[mod_path],
|
||||
bind_addr=bind_addr,
|
||||
statespace=statespace,
|
||||
)
|
||||
await portal._submit_for_result(
|
||||
mod_path,
|
||||
fn.__name__,
|
||||
**kwargs
|
||||
)
|
||||
self._cancel_after_result_on_exit.add(portal)
|
||||
return portal
|
||||
|
||||
async def wait(self):
|
||||
|
|
@ -82,27 +116,34 @@ class ActorNursery:
|
|||
# please god don't hang
|
||||
proc.join()
|
||||
log.debug(f"Joined {proc}")
|
||||
event = self._actor._peers.get(actor.uid)
|
||||
if isinstance(event, trio.Event):
|
||||
event.set()
|
||||
log.warn(
|
||||
f"Cancelled `wait_for_peer()` call since {actor.uid}"
|
||||
f" is already dead!")
|
||||
if not portal._result:
|
||||
log.debug(f"Faking result for {actor.uid}")
|
||||
q = self._actor.get_waitq(actor.uid, 'main')
|
||||
q.put_nowait({'return': None, 'cid': 'main'})
|
||||
self._children.pop(actor.uid)
|
||||
|
||||
async def wait_for_result(portal):
|
||||
if portal.channel.connected():
|
||||
log.debug(f"Waiting on final result from {subactor.uid}")
|
||||
await portal.result()
|
||||
async def wait_for_result(portal, actor):
|
||||
# cancel the actor gracefully
|
||||
log.info(f"Cancelling {portal.channel.uid} gracefully")
|
||||
await portal.cancel_actor()
|
||||
|
||||
log.debug(f"Waiting on final result from {subactor.uid}")
|
||||
res = await portal.result()
|
||||
# if it's an async-gen then we should alert the user
|
||||
# that we're cancelling it
|
||||
if inspect.isasyncgen(res):
|
||||
log.warn(
|
||||
f"Blindly consuming asyncgen for {actor.uid}")
|
||||
with trio.fail_after(1):
|
||||
async with aclosing(res) as agen:
|
||||
async for item in agen:
|
||||
log.debug(f"Consuming item {item}")
|
||||
|
||||
# unblocks when all waiter tasks have completed
|
||||
children = self._children.copy()
|
||||
async with trio.open_nursery() as nursery:
|
||||
for subactor, proc, portal in self._children.values():
|
||||
for subactor, proc, portal in children.values():
|
||||
nursery.start_soon(wait_for_proc, proc, subactor, portal)
|
||||
nursery.start_soon(wait_for_result, portal)
|
||||
if proc.is_alive() and (
|
||||
portal in self._cancel_after_result_on_exit
|
||||
):
|
||||
nursery.start_soon(wait_for_result, portal, subactor)
|
||||
|
||||
async def cancel(self, hard_kill=False):
|
||||
"""Cancel this nursery by instructing each subactor to cancel
|
||||
|
|
@ -111,20 +152,37 @@ class ActorNursery:
|
|||
If ``hard_killl`` is set to ``True`` then kill the processes
|
||||
directly without any far end graceful ``trio`` cancellation.
|
||||
"""
|
||||
def do_hard_kill(proc):
|
||||
log.warn(f"Hard killing subactors {self._children}")
|
||||
proc.terminate()
|
||||
# XXX: below doesn't seem to work?
|
||||
# send KeyBoardInterrupt (trio abort signal) to sub-actors
|
||||
# os.kill(proc.pid, signal.SIGINT)
|
||||
|
||||
log.debug(f"Cancelling nursery")
|
||||
for subactor, proc, portal in self._children.values():
|
||||
if proc is mp.current_process():
|
||||
# XXX: does this even make sense?
|
||||
await subactor.cancel()
|
||||
else:
|
||||
if hard_kill:
|
||||
log.warn(f"Hard killing subactors {self._children}")
|
||||
proc.terminate()
|
||||
# XXX: doesn't seem to work?
|
||||
# send KeyBoardInterrupt (trio abort signal) to sub-actors
|
||||
# os.kill(proc.pid, signal.SIGINT)
|
||||
else:
|
||||
await portal.cancel_actor()
|
||||
with trio.fail_after(3):
|
||||
async with trio.open_nursery() as n:
|
||||
for subactor, proc, portal in self._children.values():
|
||||
if hard_kill:
|
||||
do_hard_kill(proc)
|
||||
else:
|
||||
if portal is None: # actor hasn't fully spawned yet
|
||||
event = self._actor._peer_connected[subactor.uid]
|
||||
log.warn(
|
||||
f"{subactor.uid} wasn't finished spawning?")
|
||||
await event.wait()
|
||||
# channel/portal should now be up
|
||||
_, _, portal = self._children[subactor.uid]
|
||||
if portal is None:
|
||||
# cancelled while waiting on the event?
|
||||
chan = self._actor._peers[subactor.uid][-1]
|
||||
if chan:
|
||||
portal = Portal(chan)
|
||||
else: # there's no other choice left
|
||||
do_hard_kill(proc)
|
||||
|
||||
# spawn cancel tasks async
|
||||
n.start_soon(portal.cancel_actor)
|
||||
|
||||
log.debug(f"Waiting on all subactors to complete")
|
||||
await self.wait()
|
||||
|
|
@ -134,32 +192,37 @@ class ActorNursery:
|
|||
async def __aexit__(self, etype, value, tb):
|
||||
"""Wait on all subactor's main routines to complete.
|
||||
"""
|
||||
if etype is not None:
|
||||
# XXX: hypothetically an error could be raised and then
|
||||
# a cancel signal shows up slightly after in which case the
|
||||
# else block here might not complete? Should both be shielded?
|
||||
if etype is trio.Cancelled:
|
||||
try:
|
||||
if etype is not None:
|
||||
# XXX: hypothetically an error could be raised and then
|
||||
# a cancel signal shows up slightly after in which case the
|
||||
# else block here might not complete? Should both be shielded?
|
||||
with trio.open_cancel_scope(shield=True):
|
||||
log.warn(
|
||||
f"{current_actor().uid} was cancelled with {etype}"
|
||||
", cancelling actor nursery")
|
||||
await self.cancel()
|
||||
if etype is trio.Cancelled:
|
||||
log.warn(
|
||||
f"{current_actor().uid} was cancelled with {etype}"
|
||||
", cancelling actor nursery")
|
||||
await self.cancel()
|
||||
else:
|
||||
log.exception(
|
||||
f"{current_actor().uid} errored with {etype}, "
|
||||
"cancelling actor nursery")
|
||||
await self.cancel()
|
||||
else:
|
||||
log.exception(
|
||||
f"{current_actor().uid} errored with {etype}, "
|
||||
"cancelling actor nursery")
|
||||
await self.cancel()
|
||||
else:
|
||||
# XXX: this is effectively the lone cancellation/supervisor
|
||||
# strategy which exactly mimicks trio's behaviour
|
||||
log.debug(f"Waiting on subactors {self._children} to complete")
|
||||
try:
|
||||
await self.wait()
|
||||
except Exception as err:
|
||||
log.warn(f"Nursery caught {err}, cancelling")
|
||||
await self.cancel()
|
||||
raise
|
||||
log.debug(f"Nursery teardown complete")
|
||||
# XXX: this is effectively the lone cancellation/supervisor
|
||||
# strategy which exactly mimicks trio's behaviour
|
||||
log.debug(f"Waiting on subactors {self._children} to complete")
|
||||
try:
|
||||
await self.wait()
|
||||
except Exception as err:
|
||||
log.warn(f"Nursery caught {err}, cancelling")
|
||||
await self.cancel()
|
||||
raise
|
||||
log.debug(f"Nursery teardown complete")
|
||||
except Exception:
|
||||
log.exception("Error on nursery exit:")
|
||||
await self.wait()
|
||||
raise
|
||||
|
||||
|
||||
@asynccontextmanager
|
||||
|
|
|
|||
Loading…
Reference in New Issue