forked from goodboy/tractor
Reorg everything into private modules
Tyler Goodlet
parent
f636bfdf83
commit
64cbb922dc
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@ -12,7 +12,7 @@ def pytest_addoption(parser):
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@pytest.fixture(scope='session', autouse=True)
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def loglevel(request):
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orig = tractor._default_loglevel
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level = tractor._default_loglevel = request.config.option.loglevel
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orig = tractor.log._default_loglevel
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level = tractor.log._default_loglevel = request.config.option.loglevel
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yield level
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tractor._default_loglevel = orig
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tractor.log._default_loglevel = orig
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1019
tractor/__init__.py
1019
tractor/__init__.py
File diff suppressed because it is too large
Load Diff
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@ -0,0 +1,647 @@
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"""
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Actor primitives and helpers
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"""
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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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import trio
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from async_generator import asynccontextmanager, aclosing
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from ._ipc import Channel, _connect_chan
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from .log import get_console_log, get_logger
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from ._portal import (Portal, open_portal, _do_handshake, LocalPortal,
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maybe_open_nursery)
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from . import _state
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from ._state import current_actor
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log = get_logger('tractor')
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class ActorFailure(Exception):
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"General actor 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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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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"""
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try:
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is_async_partial = False
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is_async_gen_partial = False
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if isinstance(func, partial):
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is_async_partial = inspect.iscoroutinefunction(func.func)
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is_async_gen_partial = inspect.isasyncgenfunction(func.func)
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if (
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not inspect.iscoroutinefunction(func) and
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not inspect.isasyncgenfunction(func) and
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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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else:
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coro = func(**kwargs)
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if inspect.isasyncgen(coro):
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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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# triggered in the underlying async gen! So we
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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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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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# 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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else:
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await chan.send({'return': await coro, 'cid': cid})
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except Exception:
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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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task_status.started()
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class Actor:
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"""The fundamental concurrency primitive.
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An *actor* is the combination of a regular Python or
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``multiprocessing.Process`` executing a ``trio`` task tree, communicating
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with other actors through "portals" which provide a native async API
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around "channels".
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"""
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is_arbiter = False
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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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self.name = name
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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._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._actors2calls = {} # map {uids -> {callids -> waiter queues}}
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self._listeners = []
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self._parent_chan = None
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self._accept_host = None
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async def wait_for_peer(self, uid):
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"""Wait for a connection back from a spawned actor with a given
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``uid``.
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"""
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log.debug(f"Waiting for peer {uid} to connect")
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event = self._peer_connected.setdefault(uid, trio.Event())
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await event.wait()
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log.debug(f"{uid} successfully connected back to us")
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return event, self._peers[uid][-1]
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def load_namespaces(self):
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# We load namespaces after fork since this actor may
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# be spawned on a different machine from the original nursery
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# and we need to try and load the local module code (if it
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# exists)
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for path in self.rpc_module_paths:
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self._mods[path] = importlib.import_module(path)
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async def _stream_handler(
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self,
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stream: trio.SocketStream,
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):
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"""
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Entry point for new inbound connections to the channel server.
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"""
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self._no_more_peers.clear()
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chan = Channel(stream=stream)
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log.info(f"New connection to us {chan}")
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# send/receive initial handshake response
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try:
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uid = await _do_handshake(self, chan)
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except StopAsyncIteration:
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log.warn(f"Channel {chan} failed to handshake")
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return
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# channel tracking
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event = self._peer_connected.pop(uid, None)
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if event:
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# Instructing connection: this is likely a new channel to
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# a recently spawned actor which we'd like to control via
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# async-rpc calls.
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log.debug(f"Waking channel waiters {event.statistics()}")
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# Alert any task waiting on this connection to come up
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event.set()
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chans = self._peers[uid]
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if chans:
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log.warn(
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f"already have channel(s) for {uid}:{chans}?"
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)
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log.debug(f"Registered {chan} for {uid}")
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# append new channel
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self._peers[uid].append(chan)
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# Begin channel management - respond to remote requests and
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# process received reponses.
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try:
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await self._process_messages(chan)
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finally:
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# Drop ref to channel so it can be gc-ed and disconnected
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log.debug(f"Releasing channel {chan} from {chan.uid}")
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chans = self._peers.get(chan.uid)
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chans.remove(chan)
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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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if not self._peers: # no more channels connected
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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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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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await chan.aclose()
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async def _push_result(self, actorid, cid, msg):
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assert actorid, f"`actorid` can't be {actorid}"
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q = self.get_waitq(actorid, cid)
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log.debug(f"Delivering {msg} from {actorid} to caller {cid}")
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# maintain backpressure
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await q.put(msg)
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def get_waitq(self, actorid, cid):
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log.debug(f"Getting result queue for {actorid} cid {cid}")
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cids2qs = self._actors2calls.setdefault(actorid, {})
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return cids2qs.setdefault(cid, trio.Queue(1000))
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async def send_cmd(self, chan, ns, func, kwargs):
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"""Send a ``'cmd'`` message to a remote actor and return a
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caller id and a ``trio.Queue`` that can be used to wait for
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responses delivered by the local message processing loop.
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"""
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cid = str(uuid.uuid1())
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q = self.get_waitq(chan.uid, cid)
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log.debug(f"Sending cmd to {chan.uid}: {ns}.{func}({kwargs})")
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await chan.send({'cmd': (ns, func, kwargs, self.uid, cid)})
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return cid, q
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async def _process_messages(self, chan, treat_as_gen=False):
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"""Process messages async-RPC style.
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Process rpc requests and deliver retrieved responses from channels.
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"""
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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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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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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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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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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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# log.warn("Log level after fork is {self.loglevel}")
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from ._trionics import ctx
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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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_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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trio.run(partial(
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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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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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):
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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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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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async with maybe_open_nursery(nursery) as nursery:
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self._root_nursery = nursery
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# Startup up channel server
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host, port = accept_addr
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await nursery.start(partial(
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self._serve_forever, accept_host=host, accept_port=port)
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)
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# XXX: I wonder if a better name is maybe "requester"
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# since I don't think the notion of a "parent" actor
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# necessarily sticks given that eventually we want
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# ``'MainProcess'`` (the actor who initially starts the
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# forkserver) to eventually be the only one who is
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# allowed to spawn new processes per Python program.
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if parent_addr is not None:
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try:
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# Connect back to the parent actor and conduct initial
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# handshake (From this point on if we error ship the
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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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await _do_handshake(self, chan)
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except OSError: # failed to connect
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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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self._parent_chan = None
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# register with the arbiter if we're told its addr
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log.debug(f"Registering {self} for role `{self.name}`")
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async with get_arbiter(*arbiter_addr) as arb_portal:
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await arb_portal.run(
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'self', 'register_actor',
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name=self.name, sockaddr=self.accept_addr)
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registered_with_arbiter = True
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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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self.load_namespaces()
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if self._parent_chan:
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nursery.start_soon(
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self._process_messages, self._parent_chan)
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if self.main:
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try:
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if self._parent_chan:
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async with trio.open_nursery() as n:
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self._main_scope = n.cancel_scope
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log.debug(f"Starting main task `{self.main}`")
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# spawned subactor so deliver "main"
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# task result(s) back to parent
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await n.start(
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_invoke, 'main',
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self._parent_chan, self.main, {},
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# treat_as_gen, raise_errs params
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False, True
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)
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else:
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with trio.open_cancel_scope() as main_scope:
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self._main_scope = main_scope
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# run directly we are an "unspawned actor"
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log.debug(f"Running `{self.main}` directly")
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result = await self.main()
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finally:
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# tear down channel server in order to ensure
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# we exit normally when the main task is done
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if not self._outlive_main:
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log.debug(f"Shutting down channel server")
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self.cancel_server()
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log.debug(f"Shutting down root nursery")
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nursery.cancel_scope.cancel()
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self._main_complete.set()
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if self._main_scope.cancelled_caught:
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log.debug("Main task was cancelled sucessfully")
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log.debug("Waiting on root nursery to complete")
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# blocks here as expected if no nursery was provided until
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# the channel server is killed (i.e. this actor is
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# cancelled or signalled by the parent actor)
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except Exception:
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if self._parent_chan:
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try:
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await self._parent_chan.send(
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{'error': traceback.format_exc(), 'cid': 'main'})
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except trio.ClosedStreamError:
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log.error(
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f"Failed to ship error to parent "
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f"{self._parent_chan.uid}, channel was closed")
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log.exception("Actor errored:")
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|
||||
if not registered_with_arbiter:
|
||||
log.exception(
|
||||
f"Failed to register with arbiter @ {arbiter_addr}")
|
||||
else:
|
||||
raise
|
||||
finally:
|
||||
await self._do_unreg(arbiter_addr)
|
||||
# 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()
|
||||
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,
|
||||
*,
|
||||
# (host, port) to bind for channel server
|
||||
accept_host=None,
|
||||
accept_port=0,
|
||||
task_status=trio.TASK_STATUS_IGNORED
|
||||
):
|
||||
"""Start the channel server, begin listening for new connections.
|
||||
|
||||
This will cause an actor to continue living (blocking) until
|
||||
``cancel_server()`` is called.
|
||||
"""
|
||||
async with trio.open_nursery() as nursery:
|
||||
self._server_nursery = nursery
|
||||
# TODO: might want to consider having a separate nursery
|
||||
# for the stream handler such that the server can be cancelled
|
||||
# whilst leaving existing channels up
|
||||
listeners = await nursery.start(
|
||||
partial(
|
||||
trio.serve_tcp,
|
||||
self._stream_handler,
|
||||
# new connections will stay alive even if this server
|
||||
# is cancelled
|
||||
handler_nursery=self._root_nursery,
|
||||
port=accept_port, host=accept_host,
|
||||
)
|
||||
)
|
||||
log.debug(
|
||||
f"Started tcp server(s) on {[l.socket for l in listeners]}")
|
||||
self._listeners.extend(listeners)
|
||||
task_status.started()
|
||||
|
||||
async def _do_unreg(self, arbiter_addr):
|
||||
# UNregister actor from the arbiter
|
||||
try:
|
||||
if arbiter_addr is not None:
|
||||
async with get_arbiter(*arbiter_addr) as arb_portal:
|
||||
await arb_portal.run(
|
||||
'self', 'unregister_actor', name=self.name)
|
||||
except OSError:
|
||||
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.
|
||||
"""
|
||||
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()
|
||||
|
||||
def cancel_server(self):
|
||||
"""Cancel the internal channel server nursery thereby
|
||||
preventing any new inbound connections from being established.
|
||||
"""
|
||||
self._server_nursery.cancel_scope.cancel()
|
||||
|
||||
@property
|
||||
def accept_addr(self):
|
||||
"""Primary address to which the channel server is bound.
|
||||
"""
|
||||
try:
|
||||
return self._listeners[0].socket.getsockname()
|
||||
except OSError:
|
||||
return
|
||||
|
||||
def get_parent(self):
|
||||
return Portal(self._parent_chan)
|
||||
|
||||
def get_chans(self, actorid):
|
||||
return self._peers[actorid]
|
||||
|
||||
|
||||
class Arbiter(Actor):
|
||||
"""A special actor who knows all the other actors and always has
|
||||
access to the top level nursery.
|
||||
|
||||
The arbiter is by default the first actor spawned on each host
|
||||
and is responsible for keeping track of all other actors for
|
||||
coordination purposes. If a new main process is launched and an
|
||||
arbiter is already running that arbiter will be used.
|
||||
"""
|
||||
_registry = defaultdict(list)
|
||||
is_arbiter = True
|
||||
|
||||
def find_actor(self, name):
|
||||
return self._registry[name]
|
||||
|
||||
def register_actor(self, name, sockaddr):
|
||||
self._registry[name].append(sockaddr)
|
||||
|
||||
def unregister_actor(self, name):
|
||||
self._registry.pop(name, None)
|
||||
|
||||
|
||||
async def _start_actor(actor, host, port, arbiter_addr, nursery=None):
|
||||
"""Spawn a local actor by starting a task to execute it's main
|
||||
async function.
|
||||
|
||||
Blocks if no nursery is provided, in which case it is expected the nursery
|
||||
provider is responsible for waiting on the task to complete.
|
||||
"""
|
||||
# assign process-local actor
|
||||
_state._current_actor = actor
|
||||
|
||||
# start local channel-server and fake the portal API
|
||||
# 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:
|
||||
actor.cancel_server()
|
||||
|
||||
# unset module state
|
||||
_state._current_actor = None
|
||||
log.info("Completed async main")
|
||||
|
||||
return result
|
||||
|
||||
|
||||
@asynccontextmanager
|
||||
async def get_arbiter(host, port):
|
||||
"""Return a portal instance connected to a local or remote
|
||||
arbiter.
|
||||
"""
|
||||
actor = current_actor()
|
||||
if not actor:
|
||||
raise RuntimeError("No actor instance has been defined yet?")
|
||||
|
||||
if actor.is_arbiter:
|
||||
# we're already the arbiter
|
||||
# (likely a re-entrant call from the arbiter actor)
|
||||
yield LocalPortal(actor)
|
||||
else:
|
||||
async with _connect_chan(host, port) as chan:
|
||||
async with open_portal(chan) as arb_portal:
|
||||
yield arb_portal
|
||||
|
||||
|
||||
@asynccontextmanager
|
||||
async def find_actor(
|
||||
name,
|
||||
arbiter_sockaddr=None,
|
||||
):
|
||||
"""Ask the arbiter to find actor(s) by name.
|
||||
|
||||
Returns a connected portal to the last registered matching actor
|
||||
known to the arbiter.
|
||||
"""
|
||||
actor = current_actor()
|
||||
if not actor:
|
||||
raise RuntimeError("No actor instance has been defined yet?")
|
||||
|
||||
async with get_arbiter(*arbiter_sockaddr or actor._arb_addr) as arb_portal:
|
||||
sockaddrs = await arb_portal.run('self', 'find_actor', name=name)
|
||||
# TODO: return portals to all available actors - for now just
|
||||
# the last one that registered
|
||||
if sockaddrs:
|
||||
sockaddr = sockaddrs[-1]
|
||||
async with _connect_chan(*sockaddr) as chan:
|
||||
async with open_portal(chan) as portal:
|
||||
yield portal
|
||||
else:
|
||||
yield None
|
||||
|
|
@ -0,0 +1,205 @@
|
|||
"""
|
||||
Portal api
|
||||
"""
|
||||
import importlib
|
||||
|
||||
import trio
|
||||
from async_generator import asynccontextmanager
|
||||
|
||||
from ._state import current_actor
|
||||
from .log import get_logger
|
||||
|
||||
|
||||
log = get_logger('tractor')
|
||||
|
||||
|
||||
class RemoteActorError(RuntimeError):
|
||||
"Remote actor exception bundled locally"
|
||||
|
||||
|
||||
@asynccontextmanager
|
||||
async def maybe_open_nursery(nursery=None):
|
||||
"""Create a new nursery if None provided.
|
||||
|
||||
Blocks on exit as expected if no input nursery is provided.
|
||||
"""
|
||||
if nursery is not None:
|
||||
yield nursery
|
||||
else:
|
||||
async with trio.open_nursery() as nursery:
|
||||
yield nursery
|
||||
|
||||
|
||||
async def _do_handshake(actor, chan):
|
||||
await chan.send(actor.uid)
|
||||
uid = await chan.recv()
|
||||
|
||||
if not isinstance(uid, tuple):
|
||||
raise ValueError(f"{uid} is not a valid uid?!")
|
||||
|
||||
chan.uid = uid
|
||||
log.info(f"Handshake with actor {uid}@{chan.raddr} complete")
|
||||
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``.
|
||||
|
||||
Allows for invoking remote routines and receiving results through an
|
||||
underlying ``tractor.Channel`` as though the remote (async)
|
||||
function / generator was invoked locally.
|
||||
|
||||
Think of this like an native async IPC API.
|
||||
"""
|
||||
def __init__(self, channel):
|
||||
self.channel = channel
|
||||
self._result = None
|
||||
|
||||
async def aclose(self):
|
||||
log.debug(f"Closing {self}")
|
||||
# XXX: won't work until https://github.com/python-trio/trio/pull/460
|
||||
# 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).
|
||||
"""
|
||||
# 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:
|
||||
yield msg['yield']
|
||||
except KeyError:
|
||||
if 'stop' in msg:
|
||||
break # far end async gen terminated
|
||||
else:
|
||||
raise RemoteActorError(msg['error'])
|
||||
except GeneratorExit:
|
||||
log.debug(
|
||||
f"Cancelling async gen call {cid} to "
|
||||
f"{self.channel.uid}")
|
||||
raise
|
||||
|
||||
return yield_from_q()
|
||||
|
||||
elif resptype == 'return':
|
||||
return first_msg['return']
|
||||
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))
|
||||
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)
|
||||
return self._result
|
||||
|
||||
async def close(self):
|
||||
# trigger remote msg loop `break`
|
||||
chan = self.channel
|
||||
log.debug(f"Closing portal for {chan} to {chan.uid}")
|
||||
await self.channel.send(None)
|
||||
|
||||
async def cancel_actor(self):
|
||||
"""Cancel the actor on the other end of this portal.
|
||||
"""
|
||||
log.warn(
|
||||
f"Sending cancel request to {self.channel.uid} on "
|
||||
f"{self.channel}")
|
||||
try:
|
||||
with trio.move_on_after(0.1) as cancel_scope:
|
||||
cancel_scope.shield = True
|
||||
# send cancel cmd - might not get response
|
||||
await self.run('self', 'cancel')
|
||||
return True
|
||||
except trio.ClosedStreamError:
|
||||
log.warn(
|
||||
f"{self.channel} for {self.channel.uid} was already closed?")
|
||||
return False
|
||||
|
||||
|
||||
class LocalPortal:
|
||||
"""A 'portal' to a local ``Actor``.
|
||||
|
||||
A compatibility shim for normal portals but for invoking functions
|
||||
using an in process actor instance.
|
||||
"""
|
||||
def __init__(self, actor):
|
||||
self.actor = actor
|
||||
|
||||
async def run(self, ns, func, **kwargs):
|
||||
"""Run a requested function locally and return it's result.
|
||||
"""
|
||||
obj = self.actor if ns == 'self' else importlib.import_module(ns)
|
||||
func = getattr(obj, func)
|
||||
return func(**kwargs)
|
||||
|
||||
|
||||
@asynccontextmanager
|
||||
async def open_portal(channel, nursery=None):
|
||||
"""Open a ``Portal`` through the provided ``channel``.
|
||||
|
||||
Spawns a background task to handle message processing.
|
||||
"""
|
||||
actor = current_actor()
|
||||
assert actor
|
||||
was_connected = False
|
||||
|
||||
async with maybe_open_nursery(nursery) as nursery:
|
||||
|
||||
if not channel.connected():
|
||||
await channel.connect()
|
||||
was_connected = True
|
||||
|
||||
if channel.uid is None:
|
||||
await _do_handshake(actor, channel)
|
||||
|
||||
nursery.start_soon(actor._process_messages, channel)
|
||||
portal = Portal(channel)
|
||||
yield portal
|
||||
|
||||
# cancel remote channel-msg loop
|
||||
if channel.connected():
|
||||
await portal.close()
|
||||
|
||||
# cancel background msg loop task
|
||||
nursery.cancel_scope.cancel()
|
||||
if was_connected:
|
||||
await channel.aclose()
|
||||
|
|
@ -0,0 +1,10 @@
|
|||
"""
|
||||
Per process state
|
||||
"""
|
||||
_current_actor = None
|
||||
|
||||
|
||||
def current_actor() -> 'Actor':
|
||||
"""Get the process-local actor instance.
|
||||
"""
|
||||
return _current_actor
|
||||
|
|
@ -0,0 +1,175 @@
|
|||
"""
|
||||
``trio`` inspired apis and helpers
|
||||
"""
|
||||
import multiprocessing as mp
|
||||
|
||||
import trio
|
||||
from async_generator import asynccontextmanager
|
||||
|
||||
from ._state import current_actor
|
||||
from .log import get_logger, get_loglevel
|
||||
from ._actor import Actor, ActorFailure
|
||||
from ._portal import Portal
|
||||
|
||||
|
||||
ctx = mp.get_context("forkserver")
|
||||
log = get_logger('tractor')
|
||||
|
||||
|
||||
class ActorNursery:
|
||||
"""Spawn scoped subprocess actors.
|
||||
"""
|
||||
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 = {}
|
||||
self.cancelled = False
|
||||
|
||||
async def __aenter__(self):
|
||||
return self
|
||||
|
||||
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()
|
||||
actor = Actor(
|
||||
name,
|
||||
# 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,
|
||||
)
|
||||
parent_addr = self._actor.accept_addr
|
||||
assert parent_addr
|
||||
proc = ctx.Process(
|
||||
target=actor._fork_main,
|
||||
args=(bind_addr, parent_addr),
|
||||
# daemon=True,
|
||||
name=name,
|
||||
)
|
||||
proc.start()
|
||||
if not proc.is_alive():
|
||||
raise ActorFailure("Couldn't start sub-actor?")
|
||||
|
||||
log.info(f"Started {proc}")
|
||||
# wait for actor to spawn and connect back to us
|
||||
# channel should have handshake completed by the
|
||||
# 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)
|
||||
return portal
|
||||
|
||||
async def wait(self):
|
||||
"""Wait for all subactors to complete.
|
||||
"""
|
||||
async def wait_for_proc(proc, actor, portal):
|
||||
# TODO: timeout block here?
|
||||
if proc.is_alive():
|
||||
await trio.hazmat.wait_readable(proc.sentinel)
|
||||
# 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'})
|
||||
|
||||
async def wait_for_result(portal):
|
||||
if portal.channel.connected():
|
||||
log.debug(f"Waiting on final result from {subactor.uid}")
|
||||
await portal.result()
|
||||
|
||||
# unblocks when all waiter tasks have completed
|
||||
async with trio.open_nursery() as nursery:
|
||||
for subactor, proc, portal in self._children.values():
|
||||
nursery.start_soon(wait_for_proc, proc, subactor, portal)
|
||||
nursery.start_soon(wait_for_result, portal)
|
||||
|
||||
async def cancel(self, hard_kill=False):
|
||||
"""Cancel this nursery by instructing each subactor to cancel
|
||||
iteslf and wait for all subprocesses to terminate.
|
||||
|
||||
If ``hard_killl`` is set to ``True`` then kill the processes
|
||||
directly without any far end graceful ``trio`` cancellation.
|
||||
"""
|
||||
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()
|
||||
|
||||
log.debug(f"Waiting on all subactors to complete")
|
||||
await self.wait()
|
||||
self.cancelled = True
|
||||
log.debug(f"All subactors for {self} have terminated")
|
||||
|
||||
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:
|
||||
with trio.open_cancel_scope(shield=True):
|
||||
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:
|
||||
# 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")
|
||||
|
||||
|
||||
@asynccontextmanager
|
||||
async def open_nursery(supervisor=None):
|
||||
"""Create and yield a new ``ActorNursery``.
|
||||
"""
|
||||
actor = current_actor()
|
||||
if not actor:
|
||||
raise RuntimeError("No actor instance has been defined yet?")
|
||||
|
||||
# TODO: figure out supervisors from erlang
|
||||
async with ActorNursery(current_actor(), supervisor) as nursery:
|
||||
yield nursery
|
||||
|
|
@ -7,6 +7,7 @@ import logging
|
|||
import colorlog
|
||||
|
||||
_proj_name = 'tractor'
|
||||
_default_loglevel = None
|
||||
|
||||
# Super sexy formatting thanks to ``colorlog``.
|
||||
# (NOTE: we use the '{' format style)
|
||||
|
|
@ -89,3 +90,7 @@ def get_console_log(level: str = None, name: str = None) -> logging.Logger:
|
|||
log.addHandler(handler)
|
||||
|
||||
return log
|
||||
|
||||
|
||||
def get_loglevel():
|
||||
return _default_loglevel
|
||||
|
|
|
|||
Loading…
Reference in New Issue