Merge pull request #215 from goodboy/transport_cleaning

Transport cleaning: attempt to define our graceful channel close signal.
wats_da_nooz
goodboy 2021-07-06 08:20:19 -04:00 committed by GitHub
commit 4d530deac3
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7 changed files with 151 additions and 28 deletions

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@ -38,13 +38,20 @@ setup(
'tractor.testing',
],
install_requires=[
# trio related
'trio>0.8',
'msgpack',
'async_generator',
'trio_typing',
# tooling
'colorlog',
'wrapt',
'trio_typing',
'pdbpp',
# serialization
'msgpack',
],
tests_require=['pytest'],
python_requires=">=3.7",

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@ -123,8 +123,15 @@ def test_multierror_fast_nursery(arb_addr, start_method, num_subactors, delay):
assert exc_info.type == tractor.MultiError
err = exc_info.value
assert len(err.exceptions) == num_subactors
for exc in err.exceptions:
exceptions = err.exceptions
if len(exceptions) == 2:
# sometimes oddly now there's an embedded BrokenResourceError ?
exceptions = exceptions[1].exceptions
assert len(exceptions) == num_subactors
for exc in exceptions:
assert isinstance(exc, tractor.RemoteActorError)
assert exc.type == AssertionError

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@ -297,15 +297,31 @@ def test_multi_daemon_subactors(spawn, loglevel):
child.expect(r"\(Pdb\+\+\)")
# there is a race for which subactor will acquire
# the root's tty lock first
before = str(child.before.decode())
assert "Attaching pdb to actor: ('bp_forever'" in before
bp_forever_msg = "Attaching pdb to actor: ('bp_forever'"
name_error_msg = "NameError"
if bp_forever_msg in before:
next_msg = name_error_msg
elif name_error_msg in before:
next_msg = None
else:
raise ValueError("Neither log msg was found !?")
child.sendline('c')
# first name_error failure
child.expect(r"\(Pdb\+\+\)")
before = str(child.before.decode())
assert "NameError" in before
if next_msg:
assert next_msg in before
child.sendline('c')
@ -316,9 +332,10 @@ def test_multi_daemon_subactors(spawn, loglevel):
try:
child.sendline('c')
child.expect(pexpect.EOF)
except pexpect.exceptions.TIMEOUT:
# Failed to exit using continue..?
except pexpect.exceptions.TIMEOUT:
# Failed to exit using continue..?
child.sendline('q')
child.expect(pexpect.EOF)

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@ -27,6 +27,7 @@ from ._exceptions import (
unpack_error,
ModuleNotExposed,
is_multi_cancelled,
TransportClosed,
)
from . import _debug
from ._discovery import get_arbiter
@ -262,7 +263,7 @@ class Actor:
self._parent_chan: Optional[Channel] = None
self._forkserver_info: Optional[
Tuple[Any, Any, Any, Any, Any]] = None
self._actoruid2nursery: Dict[str, 'ActorNursery'] = {} # type: ignore
self._actoruid2nursery: Dict[str, 'ActorNursery'] = {} # type: ignore # noqa
async def wait_for_peer(
self, uid: Tuple[str, str]
@ -338,7 +339,18 @@ class Actor:
# send/receive initial handshake response
try:
uid = await self._do_handshake(chan)
except StopAsyncIteration:
except (
# trio.BrokenResourceError,
# trio.ClosedResourceError,
TransportClosed,
):
# XXX: This may propagate up from ``Channel._aiter_recv()``
# and ``MsgpackStream._inter_packets()`` on a read from the
# stream particularly when the runtime is first starting up
# inside ``open_root_actor()`` where there is a check for
# a bound listener on the "arbiter" addr. the reset will be
# because the handshake was never meant took place.
log.warning(f"Channel {chan} failed to handshake")
return
@ -578,22 +590,35 @@ class Actor:
)
await self.cancel_rpc_tasks(chan)
except trio.ClosedResourceError:
log.error(f"{chan} form {chan.uid} broke")
except (
TransportClosed,
):
# channels "breaking" (for TCP streams by EOF or 104
# connection-reset) is ok since we don't have a teardown
# handshake for them (yet) and instead we simply bail out of
# the message loop and expect the teardown sequence to clean
# up.
log.debug(f'channel from {chan.uid} closed abruptly:\n{chan}')
except (Exception, trio.MultiError) as err:
# ship any "internal" exception (i.e. one from internal machinery
# not from an rpc task) to parent
log.exception("Actor errored:")
if self._parent_chan:
await self._parent_chan.send(pack_error(err))
raise
# if this is the `MainProcess` we expect the error broadcasting
# above to trigger an error at consuming portal "checkpoints"
raise
except trio.Cancelled:
# debugging only
log.debug(f"Msg loop was cancelled for {chan}")
raise
finally:
# msg debugging for when he machinery is brokey
log.debug(
f"Exiting msg loop for {chan} from {chan.uid} "
f"with last msg:\n{msg}")

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@ -38,6 +38,10 @@ class InternalActorError(RemoteActorError):
"""
class TransportClosed(trio.ClosedResourceError):
"Underlying channel transport was closed prior to use"
class NoResult(RuntimeError):
"No final result is expected for this actor"
@ -63,12 +67,15 @@ def pack_error(exc: BaseException) -> Dict[str, Any]:
def unpack_error(
msg: Dict[str, Any],
chan=None,
err_type=RemoteActorError
) -> Exception:
"""Unpack an 'error' message from the wire
into a local ``RemoteActorError``.
"""
tb_str = msg['error'].get('tb_str', '')
return err_type(

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@ -1,6 +1,7 @@
"""
Inter-process comms abstractions
"""
import platform
import typing
from typing import Any, Tuple, Optional
from functools import partial
@ -10,7 +11,11 @@ import trio
from async_generator import asynccontextmanager
from .log import get_logger
log = get_logger('ipc')
from ._exceptions import TransportClosed
log = get_logger(__name__)
_is_windows = platform.system() == 'Windows'
# :eyeroll:
try:
@ -21,10 +26,17 @@ except ImportError:
Unpacker = partial(msgpack.Unpacker, strict_map_key=False)
class MsgpackStream:
"""A ``trio.SocketStream`` delivering ``msgpack`` formatted data.
"""
def __init__(self, stream: trio.SocketStream) -> None:
class MsgpackTCPStream:
'''A ``trio.SocketStream`` delivering ``msgpack`` formatted data
using ``msgpack-python``.
'''
def __init__(
self,
stream: trio.SocketStream,
) -> None:
self.stream = stream
assert self.stream.socket
# should both be IP sockets
@ -35,7 +47,10 @@ class MsgpackStream:
assert isinstance(rsockname, tuple)
self._raddr = rsockname[:2]
# start and seed first entry to read loop
self._agen = self._iter_packets()
# self._agen.asend(None) is None
self._send_lock = trio.StrictFIFOLock()
async def _iter_packets(self) -> typing.AsyncGenerator[dict, None]:
@ -46,16 +61,39 @@ class MsgpackStream:
use_list=False,
)
while True:
try:
data = await self.stream.receive_some(2**10)
except trio.BrokenResourceError as err:
msg = err.args[0]
# XXX: handle connection-reset-by-peer the same as a EOF.
# we're currently remapping this since we allow
# a quick connect then drop for root actors when
# checking to see if there exists an "arbiter"
# on the chosen sockaddr (``_root.py:108`` or thereabouts)
if (
# nix
'[Errno 104]' in msg or
# on windows it seems there are a variety of errors
# to handle..
_is_windows
):
raise TransportClosed(
f'{self} was broken with {msg}'
)
else:
raise
log.trace(f"received {data}") # type: ignore
except trio.BrokenResourceError:
log.warning(f"Stream connection {self.raddr} broke")
return
if data == b'':
log.debug(f"Stream connection {self.raddr} was closed")
return
raise TransportClosed(
f'transport {self} was already closed prior ro read'
)
unpacker.feed(data)
for packet in unpacker:
@ -96,10 +134,11 @@ class Channel:
on_reconnect: typing.Callable[..., typing.Awaitable] = None,
auto_reconnect: bool = False,
stream: trio.SocketStream = None, # expected to be active
) -> None:
self._recon_seq = on_reconnect
self._autorecon = auto_reconnect
self.msgstream: Optional[MsgpackStream] = MsgpackStream(
self.msgstream: Optional[MsgpackTCPStream] = MsgpackTCPStream(
stream) if stream else None
if self.msgstream and destaddr:
raise ValueError(
@ -112,6 +151,8 @@ class Channel:
self._exc: Optional[Exception] = None
self._agen = self._aiter_recv()
self._closed: bool = False
def __repr__(self) -> str:
if self.msgstream:
return repr(
@ -128,35 +169,49 @@ class Channel:
return self.msgstream.raddr if self.msgstream else None
async def connect(
self, destaddr: Tuple[Any, ...] = None,
self,
destaddr: Tuple[Any, ...] = None,
**kwargs
) -> trio.SocketStream:
if self.connected():
raise RuntimeError("channel is already connected?")
destaddr = destaddr or self._destaddr
assert isinstance(destaddr, tuple)
stream = await trio.open_tcp_stream(*destaddr, **kwargs)
self.msgstream = MsgpackStream(stream)
self.msgstream = MsgpackTCPStream(stream)
return stream
async def send(self, item: Any) -> None:
log.trace(f"send `{item}`") # type: ignore
assert self.msgstream
await self.msgstream.send(item)
async def recv(self) -> Any:
assert self.msgstream
try:
return await self.msgstream.recv()
except trio.BrokenResourceError:
if self._autorecon:
await self._reconnect()
return await self.recv()
raise
async def aclose(self) -> None:
log.debug(f"Closing {self}")
log.debug(
f'Closing channel to {self.uid} '
f'{self.laddr} -> {self.raddr}'
)
assert self.msgstream
await self.msgstream.stream.aclose()
self._closed = True
async def __aenter__(self):
await self.connect()

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@ -105,6 +105,11 @@ async def open_root_actor(
arbiter_found = False
try:
# TODO: this connect-and-bail forces us to have to carefully
# rewrap TCP 104-connection-reset errors as EOF so as to avoid
# propagating cancel-causing errors to the channel-msg loop
# machinery. Likely it would be better to eventually have
# a "discovery" protocol with basic handshake instead.
async with _connect_chan(host, port):
arbiter_found = True