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tractor
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Merge pull request #219 from goodboy/bi_streaming_no_debugger_stuff 

Initial bi-directional streaming support!
wats_da_nooz
goodboy 2021-07-31 12:27:53 -04:00 committed by GitHub
parent 4d530deac3 240f591234
commit 54d8c93f1b
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GPG Key ID: 4AEE18F83AFDEB23
22 changed files with 1982 additions and 352 deletions
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8
.github/workflows/ci.yml vendored
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@ -6,15 +6,19 @@ jobs:
mypy:
name: 'MyPy'
runs-on: ubuntu-latest
steps:
- name: Checkout
uses: actions/checkout@v2
- name: Setup python
uses: actions/setup-python@v2
with:
python-version: '3.8'
python-version: '3.9'
- name: Install dependencies
run: pip install -U . --upgrade-strategy eager
run: pip install -U . --upgrade-strategy eager -r requirements-test.txt
- name: Run MyPy check
run: mypy tractor/ --ignore-missing-imports

95
docs/README.rst
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@ -127,7 +127,8 @@ Zombie safe: self-destruct a process tree
print('This process tree will self-destruct in 1 sec...')
await trio.sleep(1)
# you could have done this yourself
# raise an error in root actor/process and trigger
# reaping of all minions
raise Exception('Self Destructed')
@ -197,6 +198,98 @@ And, yes, there's a built-in crash handling mode B)
We're hoping to add a respawn-from-repl system soon!
SC compatible bi-directional streaming
--------------------------------------
Yes, you saw it here first; we provide 2-way streams
with reliable, transitive setup/teardown semantics.
Our nascent api is remniscent of ``trio.Nursery.start()``
style invocation:
.. code:: python
import trio
import tractor
@tractor.context
async def simple_rpc(
ctx: tractor.Context,
data: int,
) -> None:
'''Test a small ping-pong 2-way streaming server.
'''
# signal to parent that we're up much like
# ``trio_typing.TaskStatus.started()``
await ctx.started(data + 1)
async with ctx.open_stream() as stream:
count = 0
async for msg in stream:
assert msg == 'ping'
await stream.send('pong')
count += 1
else:
assert count == 10
async def main() -> None:
async with tractor.open_nursery() as n:
portal = await n.start_actor(
'rpc_server',
enable_modules=[__name__],
)
# XXX: this syntax requires py3.9
async with (
portal.open_context(
simple_rpc,
data=10,
) as (ctx, sent),
ctx.open_stream() as stream,
):
assert sent == 11
count = 0
# receive msgs using async for style
await stream.send('ping')
async for msg in stream:
assert msg == 'pong'
await stream.send('ping')
count += 1
if count >= 9:
break
# explicitly teardown the daemon-actor
await portal.cancel_actor()
if __name__ == '__main__':
trio.run(main)
See original proposal and discussion in `#53`_ as well
as follow up improvements in `#223`_ that we'd love to
hear your thoughts on!
.. _#53: https://github.com/goodboy/tractor/issues/53
.. _#223: https://github.com/goodboy/tractor/issues/223
Worker poolz are easy peasy
---------------------------
The initial ask from most new users is *"how do I make a worker

72
examples/rpc_bidir_streaming.py 100644
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@ -0,0 +1,72 @@
import trio
import tractor
@tractor.context
async def simple_rpc(
ctx: tractor.Context,
data: int,
) -> None:
'''Test a small ping-pong 2-way streaming server.
'''
# signal to parent that we're up much like
# ``trio_typing.TaskStatus.started()``
await ctx.started(data + 1)
async with ctx.open_stream() as stream:
count = 0
async for msg in stream:
assert msg == 'ping'
await stream.send('pong')
count += 1
else:
assert count == 10
async def main() -> None:
async with tractor.open_nursery() as n:
portal = await n.start_actor(
'rpc_server',
enable_modules=[__name__],
)
# XXX: syntax requires py3.9
async with (
portal.open_context(
simple_rpc, # taken from pytest parameterization
data=10,
) as (ctx, sent),
ctx.open_stream() as stream,
):
assert sent == 11
count = 0
# receive msgs using async for style
await stream.send('ping')
async for msg in stream:
assert msg == 'pong'
await stream.send('ping')
count += 1
if count >= 9:
break
# explicitly teardown the daemon-actor
await portal.cancel_actor()
if __name__ == '__main__':
trio.run(main)

498
tests/test_2way.py 100644
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@ -0,0 +1,498 @@
"""
Bidirectional streaming and context API.
"""
import pytest
import trio
import tractor
from conftest import tractor_test
# the general stream semantics are
# - normal termination: far end relays a stop message which
# terminates an ongoing ``MsgStream`` iteration
# - cancel termination: context is cancelled on either side cancelling
# the "linked" inter-actor task context
_state: bool = False
@tractor.context
async def simple_setup_teardown(
ctx: tractor.Context,
data: int,
block_forever: bool = False,
) -> None:
# startup phase
global _state
_state = True
# signal to parent that we're up
await ctx.started(data + 1)
try:
if block_forever:
# block until cancelled
await trio.sleep_forever()
else:
return 'yo'
finally:
_state = False
async def assert_state(value: bool):
global _state
assert _state == value
@pytest.mark.parametrize(
'error_parent',
[False, True],
)
@pytest.mark.parametrize(
'callee_blocks_forever',
[False, True],
)
def test_simple_context(
error_parent,
callee_blocks_forever,
):
async def main():
async with tractor.open_nursery() as n:
portal = await n.start_actor(
'simple_context',
enable_modules=[__name__],
)
async with portal.open_context(
simple_setup_teardown,
data=10,
block_forever=callee_blocks_forever,
) as (ctx, sent):
assert sent == 11
if callee_blocks_forever:
await portal.run(assert_state, value=True)
await ctx.cancel()
else:
assert await ctx.result() == 'yo'
# after cancellation
await portal.run(assert_state, value=False)
if error_parent:
raise ValueError
# shut down daemon
await portal.cancel_actor()
if error_parent:
try:
trio.run(main)
except ValueError:
pass
else:
trio.run(main)
# basic stream terminations:
# - callee context closes without using stream
# - caller context closes without using stream
# - caller context calls `Context.cancel()` while streaming
# is ongoing resulting in callee being cancelled
# - callee calls `Context.cancel()` while streaming and caller
# sees stream terminated in `RemoteActorError`
# TODO: future possible features
# - restart request: far end raises `ContextRestart`
@tractor.context
async def close_ctx_immediately(
ctx: tractor.Context,
) -> None:
await ctx.started()
global _state
async with ctx.open_stream():
pass
@tractor_test
async def test_callee_closes_ctx_after_stream_open():
'callee context closes without using stream'
async with tractor.open_nursery() as n:
portal = await n.start_actor(
'fast_stream_closer',
enable_modules=[__name__],
)
async with portal.open_context(
close_ctx_immediately,
# flag to avoid waiting the final result
# cancel_on_exit=True,
) as (ctx, sent):
assert sent is None
with trio.fail_after(0.5):
async with ctx.open_stream() as stream:
# should fall through since ``StopAsyncIteration``
# should be raised through translation of
# a ``trio.EndOfChannel`` by
# ``trio.abc.ReceiveChannel.__anext__()``
async for _ in stream:
assert 0
else:
# verify stream is now closed
try:
await stream.receive()
except trio.EndOfChannel:
pass
# TODO: should be just raise the closed resource err
# directly here to enforce not allowing a re-open
# of a stream to the context (at least until a time of
# if/when we decide that's a good idea?)
try:
async with ctx.open_stream() as stream:
pass
except trio.ClosedResourceError:
pass
await portal.cancel_actor()
@tractor.context
async def expect_cancelled(
ctx: tractor.Context,
) -> None:
global _state
_state = True
await ctx.started()
try:
async with ctx.open_stream() as stream:
async for msg in stream:
await stream.send(msg) # echo server
except trio.Cancelled:
# expected case
_state = False
raise
else:
assert 0, "Wasn't cancelled!?"
@pytest.mark.parametrize(
'use_ctx_cancel_method',
[False, True],
)
@tractor_test
async def test_caller_closes_ctx_after_callee_opens_stream(
use_ctx_cancel_method: bool,
):
'caller context closes without using stream'
async with tractor.open_nursery() as n:
portal = await n.start_actor(
'ctx_cancelled',
enable_modules=[__name__],
)
async with portal.open_context(
expect_cancelled,
) as (ctx, sent):
await portal.run(assert_state, value=True)
assert sent is None
# call cancel explicitly
if use_ctx_cancel_method:
await ctx.cancel()
try:
async with ctx.open_stream() as stream:
async for msg in stream:
pass
except tractor.ContextCancelled:
raise # XXX: must be propagated to __aexit__
else:
assert 0, "Should have context cancelled?"
# channel should still be up
assert portal.channel.connected()
# ctx is closed here
await portal.run(assert_state, value=False)
else:
try:
with trio.fail_after(0.2):
await ctx.result()
assert 0, "Callee should have blocked!?"
except trio.TooSlowError:
await ctx.cancel()
try:
async with ctx.open_stream() as stream:
async for msg in stream:
pass
except tractor.ContextCancelled:
pass
else:
assert 0, "Should have received closed resource error?"
# ctx is closed here
await portal.run(assert_state, value=False)
# channel should not have been destroyed yet, only the
# inter-actor-task context
assert portal.channel.connected()
# teardown the actor
await portal.cancel_actor()
@tractor_test
async def test_multitask_caller_cancels_from_nonroot_task():
async with tractor.open_nursery() as n:
portal = await n.start_actor(
'ctx_cancelled',
enable_modules=[__name__],
)
async with portal.open_context(
expect_cancelled,
) as (ctx, sent):
await portal.run(assert_state, value=True)
assert sent is None
async with ctx.open_stream() as stream:
async def send_msg_then_cancel():
await stream.send('yo')
await portal.run(assert_state, value=True)
await ctx.cancel()
await portal.run(assert_state, value=False)
async with trio.open_nursery() as n:
n.start_soon(send_msg_then_cancel)
try:
async for msg in stream:
assert msg == 'yo'
except tractor.ContextCancelled:
raise # XXX: must be propagated to __aexit__
# channel should still be up
assert portal.channel.connected()
# ctx is closed here
await portal.run(assert_state, value=False)
# channel should not have been destroyed yet, only the
# inter-actor-task context
assert portal.channel.connected()
# teardown the actor
await portal.cancel_actor()
@tractor.context
async def cancel_self(
ctx: tractor.Context,
) -> None:
global _state
_state = True
await ctx.cancel()
try:
with trio.fail_after(0.1):
await trio.sleep_forever()
except trio.Cancelled:
raise
except trio.TooSlowError:
# should never get here
assert 0
@tractor_test
async def test_callee_cancels_before_started():
'''callee calls `Context.cancel()` while streaming and caller
sees stream terminated in `ContextCancelled`.
'''
async with tractor.open_nursery() as n:
portal = await n.start_actor(
'cancels_self',
enable_modules=[__name__],
)
try:
async with portal.open_context(
cancel_self,
) as (ctx, sent):
async with ctx.open_stream():
await trio.sleep_forever()
# raises a special cancel signal
except tractor.ContextCancelled as ce:
ce.type == trio.Cancelled
# teardown the actor
await portal.cancel_actor()
@tractor.context
async def simple_rpc(
ctx: tractor.Context,
data: int,
) -> None:
"""Test a small ping-pong server.
"""
# signal to parent that we're up
await ctx.started(data + 1)
print('opening stream in callee')
async with ctx.open_stream() as stream:
count = 0
while True:
try:
await stream.receive() == 'ping'
except trio.EndOfChannel:
assert count == 10
break
else:
print('pong')
await stream.send('pong')
count += 1
@tractor.context
async def simple_rpc_with_forloop(
ctx: tractor.Context,
data: int,
) -> None:
"""Same as previous test but using ``async for`` syntax/api.
"""
# signal to parent that we're up
await ctx.started(data + 1)
print('opening stream in callee')
async with ctx.open_stream() as stream:
count = 0
async for msg in stream:
assert msg == 'ping'
print('pong')
await stream.send('pong')
count += 1
else:
assert count == 10
@pytest.mark.parametrize(
'use_async_for',
[True, False],
)
@pytest.mark.parametrize(
'server_func',
[simple_rpc, simple_rpc_with_forloop],
)
def test_simple_rpc(server_func, use_async_for):
"""The simplest request response pattern.
"""
async def main():
async with tractor.open_nursery() as n:
portal = await n.start_actor(
'rpc_server',
enable_modules=[__name__],
)
async with portal.open_context(
server_func, # taken from pytest parameterization
data=10,
) as (ctx, sent):
assert sent == 11
async with ctx.open_stream() as stream:
if use_async_for:
count = 0
# receive msgs using async for style
print('ping')
await stream.send('ping')
async for msg in stream:
assert msg == 'pong'
print('ping')
await stream.send('ping')
count += 1
if count >= 9:
break
else:
# classic send/receive style
for _ in range(10):
print('ping')
await stream.send('ping')
assert await stream.receive() == 'pong'
# stream should terminate here
# final context result(s) should be consumed here in __aexit__()
await portal.cancel_actor()
trio.run(main)

220
tests/test_advanced_streaming.py 100644
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@ -0,0 +1,220 @@
"""
Advanced streaming patterns using bidirectional streams and contexts.
"""
import itertools
from typing import Set, Dict, List
import trio
import tractor
_registry: Dict[str, Set[tractor.ReceiveMsgStream]] = {
'even': set(),
'odd': set(),
}
async def publisher(
seed: int = 0,
) -> None:
global _registry
def is_even(i):
return i % 2 == 0
for val in itertools.count(seed):
sub = 'even' if is_even(val) else 'odd'
for sub_stream in _registry[sub].copy():
await sub_stream.send(val)
# throttle send rate to ~1kHz
# making it readable to a human user
await trio.sleep(1/1000)
@tractor.context
async def subscribe(
ctx: tractor.Context,
) -> None:
global _registry
# syn caller
await ctx.started(None)
async with ctx.open_stream() as stream:
# update subs list as consumer requests
async for new_subs in stream:
new_subs = set(new_subs)
remove = new_subs - _registry.keys()
print(f'setting sub to {new_subs} for {ctx.chan.uid}')
# remove old subs
for sub in remove:
_registry[sub].remove(stream)
# add new subs for consumer
for sub in new_subs:
_registry[sub].add(stream)
async def consumer(
subs: List[str],
) -> None:
uid = tractor.current_actor().uid
async with tractor.wait_for_actor('publisher') as portal:
async with portal.open_context(subscribe) as (ctx, first):
async with ctx.open_stream() as stream:
# flip between the provided subs dynamically
if len(subs) > 1:
for sub in itertools.cycle(subs):
print(f'setting dynamic sub to {sub}')
await stream.send([sub])
count = 0
async for value in stream:
print(f'{uid} got: {value}')
if count > 5:
break
count += 1
else: # static sub
await stream.send(subs)
async for value in stream:
print(f'{uid} got: {value}')
def test_dynamic_pub_sub():
global _registry
from multiprocessing import cpu_count
cpus = cpu_count()
async def main():
async with tractor.open_nursery() as n:
# name of this actor will be same as target func
await n.run_in_actor(publisher)
for i, sub in zip(
range(cpus - 2),
itertools.cycle(_registry.keys())
):
await n.run_in_actor(
consumer,
name=f'consumer_{sub}',
subs=[sub],
)
# make one dynamic subscriber
await n.run_in_actor(
consumer,
name='consumer_dynamic',
subs=list(_registry.keys()),
)
# block until cancelled by user
with trio.fail_after(3):
await trio.sleep_forever()
try:
trio.run(main)
except trio.TooSlowError:
pass
@tractor.context
async def one_task_streams_and_one_handles_reqresp(
ctx: tractor.Context,
) -> None:
await ctx.started()
async with ctx.open_stream() as stream:
async def pingpong():
'''Run a simple req/response service.
'''
async for msg in stream:
print('rpc server ping')
assert msg == 'ping'
print('rpc server pong')
await stream.send('pong')
async with trio.open_nursery() as n:
n.start_soon(pingpong)
for _ in itertools.count():
await stream.send('yo')
await trio.sleep(0.01)
def test_reqresp_ontopof_streaming():
'''Test a subactor that both streams with one task and
spawns another which handles a small requests-response
dialogue over the same bidir-stream.
'''
async def main():
with trio.move_on_after(2):
async with tractor.open_nursery() as n:
# name of this actor will be same as target func
portal = await n.start_actor(
'dual_tasks',
enable_modules=[__name__]
)
# flat to make sure we get at least one pong
got_pong: bool = False
async with portal.open_context(
one_task_streams_and_one_handles_reqresp,
) as (ctx, first):
assert first is None
async with ctx.open_stream() as stream:
await stream.send('ping')
async for msg in stream:
print(f'client received: {msg}')
assert msg in {'pong', 'yo'}
if msg == 'pong':
got_pong = True
await stream.send('ping')
print('client sent ping')
assert got_pong
try:
trio.run(main)
except trio.TooSlowError:
pass

8
tests/test_debugger.py
View File

@ -8,6 +8,7 @@ TODO: None of these tests have been run successfully on windows yet.
"""
import time
from os import path
import platform
import pytest
import pexpect
@ -25,6 +26,13 @@ from conftest import repodir
# - recurrent root errors
if platform.system() == 'Windows':
pytest.skip(
'Debugger tests have no windows support (yet)',
allow_module_level=True,
)
def examples_dir():
"""Return the abspath to the examples directory.
"""

8
tests/test_docs_examples.py
View File

@ -84,8 +84,8 @@ def run_example_in_subproc(loglevel, testdir, arb_addr):
if '__' not in f
and f[0] != '_'
and 'debugging' not in p[0]
],
and 'debugging' not in p[0]],
ids=lambda t: t[1],
)
def test_example(run_example_in_subproc, example_script):
@ -98,6 +98,10 @@ def test_example(run_example_in_subproc, example_script):
test_example``.
"""
ex_file = os.path.join(*example_script)
if 'rpc_bidir_streaming' in ex_file and sys.version_info < (3, 9):
pytest.skip("2-way streaming example requires py3.9 async with syntax")
with open(ex_file, 'r') as ex:
code = ex.read()

9
tests/test_streaming.py
View File

@ -32,13 +32,16 @@ async def async_gen_stream(sequence):
# block indefinitely waiting to be cancelled by ``aclose()`` call
with trio.CancelScope() as cs:
await trio.sleep(float('inf'))
await trio.sleep_forever()
assert 0
assert cs.cancelled_caught
@tractor.stream
async def context_stream(ctx, sequence):
async def context_stream(
ctx: tractor.Context,
sequence
):
for i in sequence:
await ctx.send_yield(i)
await trio.sleep(0.1)
@ -338,6 +341,8 @@ async def test_respawn_consumer_task(
print("all values streamed, BREAKING")
break
cs.cancel()
# TODO: this is justification for a
# ``ActorNursery.stream_from_actor()`` helper?
await portal.cancel_actor()

19
tractor/__init__.py
View File

@ -5,11 +5,21 @@ tractor: An actor model micro-framework built on
from trio import MultiError
from ._ipc import Channel
from ._streaming import Context, stream
from ._streaming import (
Context,
ReceiveMsgStream,
MsgStream,
stream,
context,
)
from ._discovery import get_arbiter, find_actor, wait_for_actor
from ._trionics import open_nursery
from ._state import current_actor, is_root_process
from ._exceptions import RemoteActorError, ModuleNotExposed
from ._exceptions import (
RemoteActorError,
ModuleNotExposed,
ContextCancelled,
)
from ._debug import breakpoint, post_mortem
from . import msg
from ._root import run, run_daemon, open_root_actor
@ -21,6 +31,7 @@ __all__ = [
'ModuleNotExposed',
'MultiError',
'RemoteActorError',
'ContextCancelled',
'breakpoint',
'current_actor',
'find_actor',
@ -33,7 +44,9 @@ __all__ = [
'run',
'run_daemon',
'stream',
'wait_for_actor',
'context',
'ReceiveMsgStream',
'MsgStream',
'to_asyncio',
'wait_for_actor',
]

208
tractor/_actor.py
View File

@ -14,6 +14,7 @@ from types import ModuleType
import sys
import os
from contextlib import ExitStack
import warnings
import trio # type: ignore
from trio_typing import TaskStatus
@ -27,6 +28,7 @@ from ._exceptions import (
unpack_error,
ModuleNotExposed,
is_multi_cancelled,
ContextCancelled,
TransportClosed,
)
from . import _debug
@ -44,6 +46,7 @@ class ActorFailure(Exception):
async def _invoke(
actor: 'Actor',
cid: str,
chan: Channel,
@ -56,15 +59,44 @@ async def _invoke(
"""Invoke local func and deliver result(s) over provided channel.
"""
treat_as_gen = False
cs = None
# possible a traceback (not sure what typing is for this..)
tb = None
cancel_scope = trio.CancelScope()
ctx = Context(chan, cid, cancel_scope)
cs: Optional[trio.CancelScope] = None
ctx = Context(chan, cid)
context: bool = False
if getattr(func, '_tractor_stream_function', False):
# handle decorated ``@tractor.stream`` async functions
sig = inspect.signature(func)
params = sig.parameters
# compat with old api
kwargs['ctx'] = ctx
if 'ctx' in params:
warnings.warn(
"`@tractor.stream decorated funcs should now declare "
"a `stream` arg, `ctx` is now designated for use with "
"@tractor.context",
DeprecationWarning,
stacklevel=2,
)
elif 'stream' in params:
assert 'stream' in params
kwargs['stream'] = ctx
treat_as_gen = True
elif getattr(func, '_tractor_context_function', False):
# handle decorated ``@tractor.context`` async function
kwargs['ctx'] = ctx
context = True
# errors raised inside this block are propgated back to caller
try:
if not (
@ -102,8 +134,9 @@ async def _invoke(
# `StopAsyncIteration` system here for returning a final
# value if desired
await chan.send({'stop': True, 'cid': cid})
else:
if treat_as_gen:
# one way @stream func that gets treated like an async gen
elif treat_as_gen:
await chan.send({'functype': 'asyncgen', 'cid': cid})
# XXX: the async-func may spawn further tasks which push
# back values like an async-generator would but must
@ -112,10 +145,47 @@ async def _invoke(
with cancel_scope as cs:
task_status.started(cs)
await coro
if not cs.cancelled_caught:
# task was not cancelled so we can instruct the
# far end async gen to tear down
await chan.send({'stop': True, 'cid': cid})
elif context:
# context func with support for bi-dir streaming
await chan.send({'functype': 'context', 'cid': cid})
async with trio.open_nursery() as scope_nursery:
ctx._scope_nursery = scope_nursery
cs = scope_nursery.cancel_scope
task_status.started(cs)
try:
await chan.send({'return': await coro, 'cid': cid})
except trio.Cancelled as err:
tb = err.__traceback__
if cs.cancelled_caught:
# TODO: pack in ``trio.Cancelled.__traceback__`` here
# so they can be unwrapped and displayed on the caller
# side!
fname = func.__name__
if ctx._cancel_called:
msg = f'{fname} cancelled itself'
elif cs.cancel_called:
msg = (
f'{fname} was remotely cancelled by its caller '
f'{ctx.chan.uid}'
)
# task-contex was cancelled so relay to the cancel to caller
raise ContextCancelled(
msg,
suberror_type=trio.Cancelled,
)
else:
# regular async function
await chan.send({'functype': 'asyncfunc', 'cid': cid})
@ -125,29 +195,45 @@ async def _invoke(
except (Exception, trio.MultiError) as err:
# TODO: maybe we'll want differnet "levels" of debugging
if not is_multi_cancelled(err):
log.exception("Actor crashed:")
# TODO: maybe we'll want different "levels" of debugging
# eventualy such as ('app', 'supervisory', 'runtime') ?
if not isinstance(err, trio.ClosedResourceError) and (
not is_multi_cancelled(err)
# if not isinstance(err, trio.ClosedResourceError) and (
# if not is_multi_cancelled(err) and (
entered_debug: bool = False
if not isinstance(err, ContextCancelled) or (
isinstance(err, ContextCancelled) and ctx._cancel_called
):
# XXX: is there any case where we'll want to debug IPC
# disconnects? I can't think of a reason that inspecting
# disconnects as a default?
#
# I can't think of a reason that inspecting
# this type of failure will be useful for respawns or
# recovery logic - the only case is some kind of strange bug
# in `trio` itself?
entered = await _debug._maybe_enter_pm(err)
if not entered:
# in our transport layer itself? Going to keep this
# open ended for now.
entered_debug = await _debug._maybe_enter_pm(err)
if not entered_debug:
log.exception("Actor crashed:")
# always ship errors back to caller
err_msg = pack_error(err)
err_msg = pack_error(err, tb=tb)
err_msg['cid'] = cid
try:
await chan.send(err_msg)
except trio.ClosedResourceError:
log.warning(
f"Failed to ship error to caller @ {chan.uid}")
# if we can't propagate the error that's a big boo boo
log.error(
f"Failed to ship error to caller @ {chan.uid} !?"
)
if cs is None:
# error is from above code not from rpc invocation
@ -165,7 +251,7 @@ async def _invoke(
f"Task {func} likely errored or cancelled before it started")
finally:
if not actor._rpc_tasks:
log.info("All RPC tasks have completed")
log.runtime("All RPC tasks have completed")
actor._ongoing_rpc_tasks.set()
@ -180,10 +266,10 @@ _lifetime_stack: ExitStack = ExitStack()
class Actor:
"""The fundamental concurrency primitive.
An *actor* is the combination of a regular Python or
``multiprocessing.Process`` executing a ``trio`` task tree, communicating
An *actor* is the combination of a regular Python process
executing a ``trio`` task tree, communicating
with other actors through "portals" which provide a native async API
around "channels".
around various IPC transport "channels".
"""
is_arbiter: bool = False
@ -327,14 +413,18 @@ class Actor:
raise mne
async def _stream_handler(
self,
stream: trio.SocketStream,
) -> None:
"""Entry point for new inbound connections to the channel server.
"""
self._no_more_peers = trio.Event() # unset
chan = Channel(stream=stream)
log.info(f"New connection to us {chan}")
log.runtime(f"New connection to us {chan}")
# send/receive initial handshake response
try:
@ -365,11 +455,16 @@ class Actor:
event.set()
chans = self._peers[uid]
# TODO: re-use channels for new connections instead
# of always new ones; will require changing all the
# discovery funcs
if chans:
log.warning(
log.runtime(
f"already have channel(s) for {uid}:{chans}?"
)
log.trace(f"Registered {chan} for {uid}") # type: ignore
log.runtime(f"Registered {chan} for {uid}") # type: ignore
# append new channel
self._peers[uid].append(chan)
@ -378,10 +473,24 @@ class Actor:
try:
await self._process_messages(chan)
finally:
# channel cleanup sequence
# for (channel, cid) in self._rpc_tasks.copy():
# if channel is chan:
# with trio.CancelScope(shield=True):
# await self._cancel_task(cid, channel)
# # close all consumer side task mem chans
# send_chan, _ = self._cids2qs[(chan.uid, cid)]
# assert send_chan.cid == cid # type: ignore
# await send_chan.aclose()
# Drop ref to channel so it can be gc-ed and disconnected
log.debug(f"Releasing channel {chan} from {chan.uid}")
chans = self._peers.get(chan.uid)
chans.remove(chan)
if not chans:
log.debug(f"No more channels for {chan.uid}")
self._peers.pop(chan.uid, None)
@ -394,14 +503,22 @@ class Actor:
# # XXX: is this necessary (GC should do it?)
if chan.connected():
# if the channel is still connected it may mean the far
# end has not closed and we may have gotten here due to
# an error and so we should at least try to terminate
# the channel from this end gracefully.
log.debug(f"Disconnecting channel {chan}")
try:
# send our msg loop terminate sentinel
# send a msg loop terminate sentinel
await chan.send(None)
# XXX: do we want this?
# causes "[104] connection reset by peer" on other end
# await chan.aclose()
except trio.BrokenResourceError:
log.exception(
f"Channel for {chan.uid} was already zonked..")
log.warning(f"Channel for {chan.uid} was already closed")
async def _push_result(
self,
@ -411,22 +528,32 @@ class Actor:
) -> None:
"""Push an RPC result to the local consumer's queue.
"""
actorid = chan.uid
assert actorid, f"`actorid` can't be {actorid}"
send_chan, recv_chan = self._cids2qs[(actorid, cid)]
# actorid = chan.uid
assert chan.uid, f"`chan.uid` can't be {chan.uid}"
send_chan, recv_chan = self._cids2qs[(chan.uid, cid)]
assert send_chan.cid == cid # type: ignore
if 'stop' in msg:
log.debug(f"{send_chan} was terminated at remote end")
# indicate to consumer that far end has stopped
return await send_chan.aclose()
# if 'error' in msg:
# ctx = getattr(recv_chan, '_ctx', None)
# if ctx:
# ctx._error_from_remote_msg(msg)
# log.debug(f"{send_chan} was terminated at remote end")
# # indicate to consumer that far end has stopped
# return await send_chan.aclose()
try:
log.debug(f"Delivering {msg} from {actorid} to caller {cid}")
log.debug(f"Delivering {msg} from {chan.uid} to caller {cid}")
# maintain backpressure
await send_chan.send(msg)
except trio.BrokenResourceError:
# TODO: what is the right way to handle the case where the
# local task has already sent a 'stop' / StopAsyncInteration
# to the other side but and possibly has closed the local
# feeder mem chan? Do we wait for some kind of ack or just
# let this fail silently and bubble up (currently)?
# XXX: local consumer has closed their side
# so cancel the far end streaming task
log.warning(f"{send_chan} consumer is already closed")
@ -435,7 +562,9 @@ class Actor:
self,
actorid: Tuple[str, str],
cid: str
) -> Tuple[trio.abc.SendChannel, trio.abc.ReceiveChannel]:
log.debug(f"Getting result queue for {actorid} cid {cid}")
try:
send_chan, recv_chan = self._cids2qs[(actorid, cid)]
@ -489,23 +618,28 @@ class Actor:
task_status.started(loop_cs)
async for msg in chan:
if msg is None: # loop terminate sentinel
log.debug(
f"Cancelling all tasks for {chan} from {chan.uid}")
for (channel, cid) in self._rpc_tasks:
for (channel, cid) in self._rpc_tasks.copy():
if channel is chan:
await self._cancel_task(cid, channel)
log.debug(
f"Msg loop signalled to terminate for"
f" {chan} from {chan.uid}")
break
log.trace( # type: ignore
log.transport( # type: ignore
f"Received msg {msg} from {chan.uid}")
cid = msg.get('cid')
if cid:
# deliver response to local caller/waiter
await self._push_result(chan, cid, msg)
log.debug(
f"Waiting on next msg for {chan} from {chan.uid}")
continue
@ -566,7 +700,7 @@ class Actor:
else:
# mark that we have ongoing rpc tasks
self._ongoing_rpc_tasks = trio.Event()
log.info(f"RPC func is {func}")
log.runtime(f"RPC func is {func}")
# store cancel scope such that the rpc task can be
# cancelled gracefully if requested
self._rpc_tasks[(chan, cid)] = (
@ -575,7 +709,7 @@ class Actor:
# self.cancel() was called so kill this msg loop
# and break out into ``_async_main()``
log.warning(
f"{self.uid} was remotely cancelled; "
f"Actor {self.uid} was remotely cancelled; "
"waiting on cancellation completion..")
await self._cancel_complete.wait()
loop_cs.cancel()
@ -1043,7 +1177,7 @@ class Actor:
raise ValueError(f"{uid} is not a valid uid?!")
chan.uid = uid
log.info(f"Handshake with actor {uid}@{chan.raddr} complete")
log.runtime(f"Handshake with actor {uid}@{chan.raddr} complete")
return uid

6
tractor/_debug.py
View File

@ -102,7 +102,7 @@ class PdbwTeardown(pdbpp.Pdb):
# async with aclosing(async_stdin):
# async for msg in async_stdin:
# log.trace(f"Stdin input:\n{msg}")
# log.runtime(f"Stdin input:\n{msg}")
# # encode to bytes
# bmsg = str.encode(msg)
@ -276,7 +276,7 @@ def _set_trace(actor=None):
pdb = _mk_pdb()
if actor is not None:
log.runtime(f"\nAttaching pdb to actor: {actor.uid}\n")
log.pdb(f"\nAttaching pdb to actor: {actor.uid}\n")
pdb.set_trace(
# start 2 levels up in user code
@ -306,7 +306,7 @@ breakpoint = partial(
def _post_mortem(actor):
log.runtime(f"\nAttaching to pdb in crashed actor: {actor.uid}\n")
log.pdb(f"\nAttaching to pdb in crashed actor: {actor.uid}\n")
pdb = _mk_pdb()
# custom Pdb post-mortem entry

19
tractor/_discovery.py
View File

@ -16,12 +16,14 @@ from ._state import current_actor, _runtime_vars
@asynccontextmanager
async def get_arbiter(
host: str,
port: int,
) -> typing.AsyncGenerator[Union[Portal, LocalPortal], None]:
"""Return a portal instance connected to a local or remote
'''Return a portal instance connected to a local or remote
arbiter.
"""
'''
actor = current_actor()
if not actor:
@ -33,16 +35,20 @@ async def get_arbiter(
yield LocalPortal(actor, Channel((host, port)))
else:
async with _connect_chan(host, port) as chan:
async with open_portal(chan) as arb_portal:
yield arb_portal
@asynccontextmanager
async def get_root(
**kwargs,
**kwargs,
) -> typing.AsyncGenerator[Union[Portal, LocalPortal], None]:
host, port = _runtime_vars['_root_mailbox']
assert host is not None
async with _connect_chan(host, port) as chan:
async with open_portal(chan, **kwargs) as portal:
yield portal
@ -60,12 +66,16 @@ async def find_actor(
"""
actor = current_actor()
async with get_arbiter(*arbiter_sockaddr or actor._arb_addr) as arb_portal:
sockaddr = await arb_portal.run_from_ns('self', 'find_actor', name=name)
# TODO: return portals to all available actors - for now just
# the last one that registered
if name == 'arbiter' and actor.is_arbiter:
raise RuntimeError("The current actor is the arbiter")
elif sockaddr:
async with _connect_chan(*sockaddr) as chan:
async with open_portal(chan) as portal:
yield portal
@ -83,9 +93,12 @@ async def wait_for_actor(
A portal to the first registered actor is returned.
"""
actor = current_actor()
async with get_arbiter(*arbiter_sockaddr or actor._arb_addr) as arb_portal:
sockaddrs = await arb_portal.run_from_ns('self', 'wait_for_actor', name=name)
sockaddr = sockaddrs[-1]
async with _connect_chan(*sockaddr) as chan:
async with open_portal(chan) as portal:
yield portal

66
tractor/_exceptions.py
View File

@ -1,7 +1,7 @@
"""
Our classy exception set.
"""
from typing import Dict, Any
from typing import Dict, Any, Optional, Type
import importlib
import builtins
import traceback
@ -15,17 +15,16 @@ _this_mod = importlib.import_module(__name__)
class RemoteActorError(Exception):
# TODO: local recontruction of remote exception deats
"Remote actor exception bundled locally"
def __init__(self, message, type_str, **msgdata) -> None:
super().__init__(message)
for ns in [builtins, _this_mod, trio]:
try:
self.type = getattr(ns, type_str)
break
except AttributeError:
continue
else:
self.type = Exception
def __init__(
self,
message: str,
suberror_type: Optional[Type[BaseException]] = None,
**msgdata
) -> None:
super().__init__(message)
self.type = suberror_type
self.msgdata = msgdata
# TODO: a trio.MultiError.catch like context manager
@ -41,6 +40,9 @@ class InternalActorError(RemoteActorError):
class TransportClosed(trio.ClosedResourceError):
"Underlying channel transport was closed prior to use"
class ContextCancelled(RemoteActorError):
"Inter-actor task context cancelled itself on the callee side."
class NoResult(RuntimeError):
"No final result is expected for this actor"
@ -54,13 +56,22 @@ class NoRuntime(RuntimeError):
"The root actor has not been initialized yet"
def pack_error(exc: BaseException) -> Dict[str, Any]:
def pack_error(
exc: BaseException,
tb = None,
) -> Dict[str, Any]:
"""Create an "error message" for tranmission over
a channel (aka the wire).
"""
if tb:
tb_str = ''.join(traceback.format_tb(tb))
else:
tb_str = traceback.format_exc()
return {
'error': {
'tb_str': traceback.format_exc(),
'tb_str': tb_str,
'type_str': type(exc).__name__,
}
}
@ -77,12 +88,35 @@ def unpack_error(
into a local ``RemoteActorError``.
"""
tb_str = msg['error'].get('tb_str', '')
return err_type(
f"{chan.uid}\n" + tb_str,
error = msg['error']
tb_str = error.get('tb_str', '')
message = f"{chan.uid}\n" + tb_str
type_name = error['type_str']
suberror_type: Type[BaseException] = Exception
if type_name == 'ContextCancelled':
err_type = ContextCancelled
suberror_type = trio.Cancelled
else: # try to lookup a suitable local error type
for ns in [builtins, _this_mod, trio]:
try:
suberror_type = getattr(ns, type_name)
break
except AttributeError:
continue
exc = err_type(
message,
suberror_type=suberror_type,
# unpack other fields into error type init
**msg['error'],
)
return exc
def is_multi_cancelled(exc: BaseException) -> bool:
"""Predicate to determine if a ``trio.MultiError`` contains only

26
tractor/_ipc.py
View File

@ -1,5 +1,6 @@
"""
Inter-process comms abstractions
"""
import platform
import typing
@ -61,7 +62,6 @@ class MsgpackTCPStream:
use_list=False,
)
while True:
try:
data = await self.stream.receive_some(2**10)
@ -88,7 +88,7 @@ class MsgpackTCPStream:
else:
raise
log.trace(f"received {data}") # type: ignore
log.transport(f"received {data}") # type: ignore
if data == b'':
raise TransportClosed(
@ -169,6 +169,7 @@ class Channel:
return self.msgstream.raddr if self.msgstream else None
async def connect(
self,
destaddr: Tuple[Any, ...] = None,
**kwargs
@ -180,13 +181,21 @@ class Channel:
destaddr = destaddr or self._destaddr
assert isinstance(destaddr, tuple)
stream = await trio.open_tcp_stream(*destaddr, **kwargs)
stream = await trio.open_tcp_stream(
*destaddr,
**kwargs
)
self.msgstream = MsgpackTCPStream(stream)
log.transport(
f'Opened channel to peer {self.laddr} -> {self.raddr}'
)
return stream
async def send(self, item: Any) -> None:
log.trace(f"send `{item}`") # type: ignore
log.transport(f"send `{item}`") # type: ignore
assert self.msgstream
await self.msgstream.send(item)
@ -205,7 +214,8 @@ class Channel:
raise
async def aclose(self) -> None:
log.debug(
log.transport(
f'Closing channel to {self.uid} '
f'{self.laddr} -> {self.raddr}'
)
@ -234,11 +244,11 @@ class Channel:
await self.connect()
cancelled = cancel_scope.cancelled_caught
if cancelled:
log.warning(
log.transport(
"Reconnect timed out after 3 seconds, retrying...")
continue
else:
log.warning("Stream connection re-established!")
log.transport("Stream connection re-established!")
# run any reconnection sequence
on_recon = self._recon_seq
if on_recon:
@ -247,7 +257,7 @@ class Channel:
except (OSError, ConnectionRefusedError):
if not down:
down = True
log.warning(
log.transport(
f"Connection to {self.raddr} went down, waiting"
" for re-establishment")
await trio.sleep(1)

157
tractor/_portal.py
View File

@ -17,7 +17,12 @@ from async_generator import asynccontextmanager
from ._state import current_actor
from ._ipc import Channel
from .log import get_logger
from ._exceptions import unpack_error, NoResult, RemoteActorError
from ._exceptions import (
unpack_error,
NoResult,
RemoteActorError,
ContextCancelled,
)
from ._streaming import Context, ReceiveMsgStream
@ -84,7 +89,7 @@ class Portal:
ns: str,
func: str,
kwargs,
) -> Tuple[str, trio.abc.ReceiveChannel, str, Dict[str, Any]]:
) -> Tuple[str, trio.MemoryReceiveChannel, str, Dict[str, Any]]:
"""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.
@ -172,6 +177,7 @@ class Portal:
f"Cancelling all streams with {self.channel.uid}")
for stream in self._streams.copy():
try:
# with trio.CancelScope(shield=True):
await stream.aclose()
except trio.ClosedResourceError:
# don't error the stream having already been closed
@ -289,6 +295,7 @@ class Portal:
self,
async_gen_func: Callable, # typing: ignore
**kwargs,
) -> AsyncGenerator[ReceiveMsgStream, None]:
if not inspect.isasyncgenfunction(async_gen_func):
@ -312,13 +319,23 @@ class Portal:
ctx = Context(self.channel, cid, _portal=self)
try:
async with ReceiveMsgStream(ctx, recv_chan, self) as rchan:
# deliver receive only stream
async with ReceiveMsgStream(ctx, recv_chan) as rchan:
self._streams.add(rchan)
yield rchan
finally:
# cancel the far end task on consumer close
# NOTE: this is a special case since we assume that if using
# this ``.open_fream_from()`` api, the stream is one a one
# time use and we couple the far end tasks's lifetime to
# the consumer's scope; we don't ever send a `'stop'`
# message right now since there shouldn't be a reason to
# stop and restart the stream, right?
try:
await ctx.cancel()
except trio.ClosedResourceError:
# if the far end terminates before we send a cancel the
# underlying transport-channel may already be closed.
@ -326,16 +343,123 @@ class Portal:
self._streams.remove(rchan)
# @asynccontextmanager
# async def open_context(
# self,
# func: Callable,
# **kwargs,
# ) -> Context:
# # TODO
# elif resptype == 'context': # context manager style setup/teardown
# # TODO likely not here though
# raise NotImplementedError
@asynccontextmanager
async def open_context(
self,
func: Callable,
**kwargs,
) -> AsyncGenerator[Tuple[Context, Any], None]:
'''Open an inter-actor task context.
This is a synchronous API which allows for deterministic
setup/teardown of a remote task. The yielded ``Context`` further
allows for opening bidirectional streams, explicit cancellation
and synchronized final result collection. See ``tractor.Context``.
'''
# conduct target func method structural checks
if not inspect.iscoroutinefunction(func) and (
getattr(func, '_tractor_contex_function', False)
):
raise TypeError(
f'{func} must be an async generator function!')
fn_mod_path, fn_name = func_deats(func)
recv_chan: Optional[trio.MemoryReceiveChannel] = None
cid, recv_chan, functype, first_msg = await self._submit(
fn_mod_path, fn_name, kwargs)
assert functype == 'context'
msg = await recv_chan.receive()
try:
# the "first" value here is delivered by the callee's
# ``Context.started()`` call.
first = msg['started']
except KeyError:
assert msg.get('cid'), ("Received internal error at context?")
if msg.get('error'):
# raise the error message
raise unpack_error(msg, self.channel)
else:
raise
_err: Optional[BaseException] = None
# deliver context instance and .started() msg value in open tuple.
try:
async with trio.open_nursery() as scope_nursery:
ctx = Context(
self.channel,
cid,
_portal=self,
_recv_chan=recv_chan,
_scope_nursery=scope_nursery,
)
# pairs with handling in ``Actor._push_result()``
# recv_chan._ctx = ctx
# await trio.lowlevel.checkpoint()
yield ctx, first
except ContextCancelled as err:
_err = err
if not ctx._cancel_called:
# context was cancelled at the far end but was
# not part of this end requesting that cancel
# so raise for the local task to respond and handle.
raise
# if the context was cancelled by client code
# then we don't need to raise since user code
# is expecting this and the block should exit.
else:
log.debug(f'Context {ctx} cancelled gracefully')
except (
trio.Cancelled,
trio.MultiError,
Exception,
) as err:
_err = err
# the context cancels itself on any cancel
# causing error.
log.error(f'Context {ctx} sending cancel to far end')
with trio.CancelScope(shield=True):
await ctx.cancel()
raise
finally:
result = await ctx.result()
# though it should be impossible for any tasks
# operating *in* this scope to have survived
# we tear down the runtime feeder chan last
# to avoid premature stream clobbers.
if recv_chan is not None:
await recv_chan.aclose()
if _err:
if ctx._cancel_called:
log.warning(
f'Context {fn_name} cancelled by caller with\n{_err}'
)
elif _err is not None:
log.warning(
f'Context {fn_name} cancelled by callee with\n{_err}'
)
else:
log.info(
f'Context {fn_name} returned '
f'value from callee `{result}`'
)
@dataclass
@ -360,10 +484,12 @@ class LocalPortal:
@asynccontextmanager
async def open_portal(
channel: Channel,
nursery: Optional[trio.Nursery] = None,
start_msg_loop: bool = True,
shield: bool = False,
) -> AsyncGenerator[Portal, None]:
"""Open a ``Portal`` through the provided ``channel``.
@ -374,6 +500,7 @@ async def open_portal(
was_connected = False
async with maybe_open_nursery(nursery, shield=shield) as nursery:
if not channel.connected():
await channel.connect()
was_connected = True
@ -395,12 +522,14 @@ async def open_portal(
portal = Portal(channel)
try:
yield portal
finally:
await portal.aclose()
if was_connected:
# cancel remote channel-msg loop
# gracefully signal remote channel-msg loop
await channel.send(None)
# await channel.aclose()
# cancel background msg loop task
if msg_loop_cs:

4
tractor/_root.py
View File

@ -86,6 +86,9 @@ async def open_root_actor(
# for use of ``await tractor.breakpoint()``
enable_modules.append('tractor._debug')
if loglevel is None:
loglevel = 'pdb'
elif debug_mode:
raise RuntimeError(
"Debug mode is only supported for the `trio` backend!"
@ -179,7 +182,6 @@ async def open_root_actor(
finally:
logger.info("Shutting down root actor")
with trio.CancelScope(shield=True):
await actor.cancel()
finally:
_state._current_actor = None

56
tractor/_spawn.py
View File

@ -22,7 +22,10 @@ from multiprocessing import forkserver # type: ignore
from typing import Tuple
from . import _forkserver_override
from ._state import current_actor, is_main_process
from ._state import (
current_actor,
is_main_process,
)
from .log import get_logger
from ._portal import Portal
from ._actor import Actor, ActorFailure
@ -149,6 +152,27 @@ async def cancel_on_completion(
await portal.cancel_actor()
async def do_hard_kill(
proc: trio.Process,
) -> None:
# NOTE: this timeout used to do nothing since we were shielding
# the ``.wait()`` inside ``new_proc()`` which will pretty much
# never release until the process exits, now it acts as
# a hard-kill time ultimatum.
with trio.move_on_after(3) as cs:
# NOTE: This ``__aexit__()`` shields internally.
async with proc: # calls ``trio.Process.aclose()``
log.debug(f"Terminating {proc}")
if cs.cancelled_caught:
# XXX: should pretty much never get here unless we have
# to move the bits from ``proc.__aexit__()`` out and
# into here.
log.critical(f"HARD KILLING {proc}")
proc.kill()
@asynccontextmanager
async def spawn_subactor(
subactor: 'Actor',
@ -180,26 +204,15 @@ async def spawn_subactor(
proc = await trio.open_process(spawn_cmd)
try:
yield proc
finally:
# XXX: do this **after** cancellation/tearfown
# to avoid killing the process too early
# since trio does this internally on ``__aexit__()``
# NOTE: we always "shield" join sub procs in
# the outer scope since no actor zombies are
# ever allowed. This ``__aexit__()`` also shields
# internally.
log.debug(f"Attempting to kill {proc}")
# NOTE: this timeout effectively does nothing right now since
# we are shielding the ``.wait()`` inside ``new_proc()`` which
# will pretty much never release until the process exits.
with trio.move_on_after(3) as cs:
async with proc:
log.debug(f"Terminating {proc}")
if cs.cancelled_caught:
log.critical(f"HARD KILLING {proc}")
proc.kill()
await do_hard_kill(proc)
async def new_proc(
@ -212,7 +225,6 @@ async def new_proc(
parent_addr: Tuple[str, int],
_runtime_vars: Dict[str, Any], # serialized and sent to _child
*,
use_trio_run_in_process: bool = False,
task_status: TaskStatus[Portal] = trio.TASK_STATUS_IGNORED
) -> None:
"""Create a new ``multiprocessing.Process`` using the
@ -223,7 +235,7 @@ async def new_proc(
# mark the new actor with the global spawn method
subactor._spawn_method = _spawn_method
if use_trio_run_in_process or _spawn_method == 'trio':
if _spawn_method == 'trio':
async with trio.open_nursery() as nursery:
async with spawn_subactor(
subactor,
@ -277,9 +289,14 @@ async def new_proc(
# reaping more stringently without the shield
# we used to have below...
# always "hard" join sub procs:
# no actor zombies allowed
# with trio.CancelScope(shield=True):
# async with proc:
# Always "hard" join sub procs since no actor zombies
# are allowed!
# this is a "light" (cancellable) join, the hard join is
# in the enclosing scope (see above).
await proc.wait()
log.debug(f"Joined {proc}")
@ -320,7 +337,6 @@ async def mp_new_proc(
parent_addr: Tuple[str, int],
_runtime_vars: Dict[str, Any], # serialized and sent to _child
*,
use_trio_run_in_process: bool = False,
task_status: TaskStatus[Portal] = trio.TASK_STATUS_IGNORED
) -> None:

658
tractor/_streaming.py
View File

@ -1,41 +1,312 @@
"""
Message stream types and APIs.
"""
import inspect
from contextlib import contextmanager # , asynccontextmanager
from contextlib import contextmanager, asynccontextmanager
from dataclasses import dataclass
from typing import Any, Iterator, Optional
from typing import (
Any, Iterator, Optional, Callable,
AsyncGenerator, Dict,
)
import warnings
import trio
from ._ipc import Channel
from ._exceptions import unpack_error
from ._exceptions import unpack_error, ContextCancelled
from ._state import current_actor
from .log import get_logger
log = get_logger(__name__)
@dataclass(frozen=True)
class Context:
"""An IAC (inter-actor communication) context.
# TODO: generic typing like trio's receive channel
# but with msgspec messages?
# class ReceiveChannel(AsyncResource, Generic[ReceiveType]):
Allows maintaining task or protocol specific state between communicating
actors. A unique context is created on the receiving end for every request
to a remote actor.
A context can be cancelled and (eventually) restarted from
either side of the underlying IPC channel.
class ReceiveMsgStream(trio.abc.ReceiveChannel):
"""A wrapper around a ``trio._channel.MemoryReceiveChannel`` with
special behaviour for signalling stream termination across an
inter-actor ``Channel``. This is the type returned to a local task
which invoked a remote streaming function using `Portal.run()`.
A context can be used to open task oriented message streams.
Termination rules:
- if the local task signals stop iteration a cancel signal is
relayed to the remote task indicating to stop streaming
- if the remote task signals the end of a stream, raise
a ``StopAsyncIteration`` to terminate the local ``async for``
"""
def __init__(
self,
ctx: 'Context', # typing: ignore # noqa
rx_chan: trio.abc.ReceiveChannel,
shield: bool = False,
) -> None:
self._ctx = ctx
self._rx_chan = rx_chan
self._shielded = shield
# flag to denote end of stream
self._eoc: bool = False
# delegate directly to underlying mem channel
def receive_nowait(self):
msg = self._rx_chan.receive_nowait()
return msg['yield']
async def receive(self):
# see ``.aclose()`` for notes on the old behaviour prior to
# introducing this
if self._eoc:
raise trio.EndOfChannel
try:
msg = await self._rx_chan.receive()
return msg['yield']
except KeyError:
# internal error should never get here
assert msg.get('cid'), ("Received internal error at portal?")
# TODO: handle 2 cases with 3.10 match syntax
# - 'stop'
# - 'error'
# possibly just handle msg['stop'] here!
if msg.get('stop'):
log.debug(f"{self} was stopped at remote end")
# # when the send is closed we assume the stream has
# # terminated and signal this local iterator to stop
# await self.aclose()
# XXX: this causes ``ReceiveChannel.__anext__()`` to
# raise a ``StopAsyncIteration`` **and** in our catch
# block below it will trigger ``.aclose()``.
raise trio.EndOfChannel
# TODO: test that shows stream raising an expected error!!!
elif msg.get('error'):
# raise the error message
raise unpack_error(msg, self._ctx.chan)
else:
raise
except (
trio.ClosedResourceError, # by self._rx_chan
trio.EndOfChannel, # by self._rx_chan or `stop` msg from far end
trio.Cancelled, # by local cancellation
):
# XXX: we close the stream on any of these error conditions:
# a ``ClosedResourceError`` indicates that the internal
# feeder memory receive channel was closed likely by the
# runtime after the associated transport-channel
# disconnected or broke.
# an ``EndOfChannel`` indicates either the internal recv
# memchan exhausted **or** we raisesd it just above after
# receiving a `stop` message from the far end of the stream.
# Previously this was triggered by calling ``.aclose()`` on
# the send side of the channel inside
# ``Actor._push_result()`` (should still be commented code
# there - which should eventually get removed), but now the
# 'stop' message handling has been put just above.
# TODO: Locally, we want to close this stream gracefully, by
# terminating any local consumers tasks deterministically.
# One we have broadcast support, we **don't** want to be
# closing this stream and not flushing a final value to
# remaining (clone) consumers who may not have been
# scheduled to receive it yet.
# when the send is closed we assume the stream has
# terminated and signal this local iterator to stop
await self.aclose()
raise # propagate
@contextmanager
def shield(
self
) -> Iterator['ReceiveMsgStream']: # noqa
"""Shield this stream's underlying channel such that a local consumer task
can be cancelled (and possibly restarted) using ``trio.Cancelled``.
Note that here, "shielding" here guards against relaying
a ``'stop'`` message to the far end of the stream thus keeping
the stream machinery active and ready for further use, it does
not have anything to do with an internal ``trio.CancelScope``.
"""
self._shielded = True
yield self
self._shielded = False
async def aclose(self):
"""Cancel associated remote actor task and local memory channel
on close.
"""
# XXX: keep proper adherance to trio's `.aclose()` semantics:
# https://trio.readthedocs.io/en/stable/reference-io.html#trio.abc.AsyncResource.aclose
rx_chan = self._rx_chan
if rx_chan._closed:
log.warning(f"{self} is already closed")
# this stream has already been closed so silently succeed as
# per ``trio.AsyncResource`` semantics.
# https://trio.readthedocs.io/en/stable/reference-io.html#trio.abc.AsyncResource.aclose
return
# TODO: broadcasting to multiple consumers
# stats = rx_chan.statistics()
# if stats.open_receive_channels > 1:
# # if we've been cloned don't kill the stream
# log.debug(
# "there are still consumers running keeping stream alive")
# return
if self._shielded:
log.warning(f"{self} is shielded, portal channel being kept alive")
return
# XXX: This must be set **AFTER** the shielded test above!
self._eoc = True
# NOTE: this is super subtle IPC messaging stuff:
# Relay stop iteration to far end **iff** we're
# in bidirectional mode. If we're only streaming
# *from* one side then that side **won't** have an
# entry in `Actor._cids2qs` (maybe it should though?).
# So any `yield` or `stop` msgs sent from the caller side
# will cause key errors on the callee side since there is
# no entry for a local feeder mem chan since the callee task
# isn't expecting messages to be sent by the caller.
# Thus, we must check that this context DOES NOT
# have a portal reference to ensure this is indeed the callee
# side and can relay a 'stop'.
# In the bidirectional case, `Context.open_stream()` will create
# the `Actor._cids2qs` entry from a call to
# `Actor.get_memchans()` and will send the stop message in
# ``__aexit__()`` on teardown so it **does not** need to be
# called here.
if not self._ctx._portal:
try:
# only for 2 way streams can we can send
# stop from the caller side
await self._ctx.send_stop()
except (
trio.BrokenResourceError,
trio.ClosedResourceError
):
# the underlying channel may already have been pulled
# in which case our stop message is meaningless since
# it can't traverse the transport.
log.debug(f'Channel for {self} was already closed')
# close the local mem chan ``self._rx_chan`` ??!?
# DEFINITELY NOT if we're a bi-dir ``MsgStream``!
# BECAUSE this same core-msg-loop mem recv-chan is used to deliver
# the potential final result from the surrounding inter-actor
# `Context` so we don't want to close it until that context has
# run to completion.
# XXX: Notes on old behaviour:
# await rx_chan.aclose()
# In the receive-only case, ``Portal.open_stream_from()`` used
# to rely on this call explicitly on teardown such that a new
# call to ``.receive()`` after ``rx_chan`` had been closed, would
# result in us raising a ``trio.EndOfChannel`` (since we
# remapped the ``trio.ClosedResourceError`). However, now if for some
# reason the stream's consumer code tries to manually receive a new
# value before ``.aclose()`` is called **but** the far end has
# stopped `.receive()` **must** raise ``trio.EndofChannel`` in
# order to avoid an infinite hang on ``.__anext__()``; this is
# why we added ``self._eoc`` to denote stream closure indepedent
# of ``rx_chan``.
# In theory we could still use this old method and close the
# underlying msg-loop mem chan as above and then **not** check
# for ``self._eoc`` in ``.receive()`` (if for some reason we
# think that check is a bottle neck - not likely) **but** then
# we would need to map the resulting
# ``trio.ClosedResourceError`` to a ``trio.EndOfChannel`` in
# ``.receive()`` (as it originally was before bi-dir streaming
# support) in order to trigger stream closure. The old behaviour
# is arguably more confusing since we lose detection of the
# runtime's closure of ``rx_chan`` in the case where we may
# still need to consume msgs that are "in transit" from the far
# end (eg. for ``Context.result()``).
class MsgStream(ReceiveMsgStream, trio.abc.Channel):
"""
Bidirectional message stream for use within an inter-actor actor
``Context```.
"""
async def send(
self,
data: Any
) -> None:
'''Send a message over this stream to the far end.
'''
await self._ctx.chan.send({'yield': data, 'cid': self._ctx.cid})
# TODO: but make it broadcasting to consumers
def clone(self):
"""Clone this receive channel allowing for multi-task
consumption from the same channel.
"""
return MsgStream(
self._ctx,
self._rx_chan.clone(),
)
@dataclass
class Context:
'''An inter-actor task communication context.
Allows maintaining task or protocol specific state between
2 communicating actor tasks. A unique context is created on the
callee side/end for every request to a remote actor from a portal.
A context can be cancelled and (possibly eventually restarted) from
either side of the underlying IPC channel.
A context can be used to open task oriented message streams and can
be thought of as an IPC aware inter-actor cancel scope.
'''
chan: Channel
cid: str
# only set on the caller side
_portal: Optional['Portal'] = None # type: ignore # noqa
_recv_chan: Optional[trio.MemoryReceiveChannel] = None
_result: Optional[Any] = False
_cancel_called: bool = False
# only set on the callee side
_cancel_scope: Optional[trio.CancelScope] = None
_scope_nursery: Optional[trio.Nursery] = None
async def send_yield(self, data: Any) -> None:
@ -50,15 +321,42 @@ class Context:
async def send_stop(self) -> None:
await self.chan.send({'stop': True, 'cid': self.cid})
def _error_from_remote_msg(
self,
msg: Dict[str, Any],
) -> None:
'''Unpack and raise a msg error into the local scope
nursery for this context.
Acts as a form of "relay" for a remote error raised
in the corresponding remote callee task.
'''
assert self._scope_nursery
async def raiser():
raise unpack_error(msg, self.chan)
self._scope_nursery.start_soon(raiser)
async def cancel(self) -> None:
"""Cancel this inter-actor-task context.
'''Cancel this inter-actor-task context.
Request that the far side cancel it's current linked context,
timeout quickly to sidestep 2-generals...
Timeout quickly in an attempt to sidestep 2-generals...
"""
assert self._portal, (
"No portal found, this is likely a callee side context")
'''
side = 'caller' if self._portal else 'callee'
log.warning(f'Cancelling {side} side of context to {self.chan}')
self._cancel_called = True
if side == 'caller':
if not self._portal:
raise RuntimeError(
"No portal found, this is likely a callee side context"
)
cid = self.cid
with trio.move_on_after(0.5) as cs:
@ -76,27 +374,176 @@ class Context:
# XXX: there's no way to know if the remote task was indeed
# cancelled in the case where the connection is broken or
# some other network error occurred.
if not self._portal.channel.connected():
# if not self._portal.channel.connected():
if not self.chan.connected():
log.warning(
"May have failed to cancel remote task "
f"{cid} for {self._portal.channel.uid}")
else:
# callee side remote task
# TODO: should we have an explicit cancel message
# or is relaying the local `trio.Cancelled` as an
# {'error': trio.Cancelled, cid: "blah"} enough?
# This probably gets into the discussion in
# https://github.com/goodboy/tractor/issues/36
assert self._scope_nursery
self._scope_nursery.cancel_scope.cancel()
if self._recv_chan:
await self._recv_chan.aclose()
@asynccontextmanager
async def open_stream(
self,
shield: bool = False,
) -> AsyncGenerator[MsgStream, None]:
'''Open a ``MsgStream``, a bi-directional stream connected to the
cross-actor (far end) task for this ``Context``.
This context manager must be entered on both the caller and
callee for the stream to logically be considered "connected".
A ``MsgStream`` is currently "one-shot" use, meaning if you
close it you can not "re-open" it for streaming and instead you
must re-establish a new surrounding ``Context`` using
``Portal.open_context()``. In the future this may change but
currently there seems to be no obvious reason to support
"re-opening":
- pausing a stream can be done with a message.
- task errors will normally require a restart of the entire
scope of the inter-actor task context due to the nature of
``trio``'s cancellation system.
'''
actor = current_actor()
# here we create a mem chan that corresponds to the
# far end caller / callee.
# NOTE: in one way streaming this only happens on the
# caller side inside `Actor.send_cmd()` so if you try
# to send a stop from the caller to the callee in the
# single-direction-stream case you'll get a lookup error
# currently.
_, recv_chan = actor.get_memchans(
self.chan.uid,
self.cid
)
# Likewise if the surrounding context has been cancelled we error here
# since it likely means the surrounding block was exited or
# killed
if self._cancel_called:
task = trio.lowlevel.current_task().name
raise ContextCancelled(
f'Context around {actor.uid[0]}:{task} was already cancelled!'
)
# XXX: If the underlying channel feeder receive mem chan has
# been closed then likely client code has already exited
# a ``.open_stream()`` block prior or there was some other
# unanticipated error or cancellation from ``trio``.
if recv_chan._closed:
raise trio.ClosedResourceError(
'The underlying channel for this stream was already closed!?')
async with MsgStream(
ctx=self,
rx_chan=recv_chan,
shield=shield,
) as rchan:
if self._portal:
self._portal._streams.add(rchan)
try:
# ensure we aren't cancelled before delivering
# the stream
# await trio.lowlevel.checkpoint()
yield rchan
except trio.EndOfChannel:
# likely the far end sent us a 'stop' message to
# terminate the stream.
raise
else:
# XXX: Make the stream "one-shot use". On exit, signal
# ``trio.EndOfChannel``/``StopAsyncIteration`` to the
# far end.
await self.send_stop()
finally:
if self._portal:
self._portal._streams.remove(rchan)
async def result(self) -> Any:
'''From a caller side, wait for and return the final result from
the callee side task.
'''
assert self._portal, "Context.result() can not be called from callee!"
assert self._recv_chan
if self._result is False:
if not self._recv_chan._closed: # type: ignore
# wait for a final context result consuming
# and discarding any bi dir stream msgs still
# in transit from the far end.
while True:
msg = await self._recv_chan.receive()
try:
self._result = msg['return']
break
except KeyError:
if 'yield' in msg:
# far end task is still streaming to us..
log.warning(f'Remote stream deliverd {msg}')
# do disard
continue
elif 'stop' in msg:
log.debug('Remote stream terminated')
continue
# internal error should never get here
assert msg.get('cid'), (
"Received internal error at portal?")
raise unpack_error(msg, self._portal.channel)
return self._result
async def started(self, value: Optional[Any] = None) -> None:
if self._portal:
raise RuntimeError(
f"Caller side context {self} can not call started!")
await self.chan.send({'started': value, 'cid': self.cid})
# TODO: do we need a restart api?
# async def restart(self) -> None:
# # TODO
# pass
# @asynccontextmanager
# async def open_stream(
# self,
# ) -> AsyncContextManager:
# # TODO
# pass
def stream(func):
def stream(func: Callable) -> Callable:
"""Mark an async function as a streaming routine with ``@stream``.
"""
func._tractor_stream_function = True
# annotate
# TODO: apply whatever solution ``mypy`` ends up picking for this:
# https://github.com/python/mypy/issues/2087#issuecomment-769266912
func._tractor_stream_function = True # type: ignore
sig = inspect.signature(func)
params = sig.parameters
if 'stream' not in params and 'ctx' in params:
@ -114,147 +561,26 @@ def stream(func):
):
raise TypeError(
"The first argument to the stream function "
f"{func.__name__} must be `ctx: tractor.Context`"
f"{func.__name__} must be `ctx: tractor.Context` "
"(Or ``to_trio`` if using ``asyncio`` in guest mode)."
)
return func
class ReceiveMsgStream(trio.abc.ReceiveChannel):
"""A wrapper around a ``trio._channel.MemoryReceiveChannel`` with
special behaviour for signalling stream termination across an
inter-actor ``Channel``. This is the type returned to a local task
which invoked a remote streaming function using `Portal.run()`.
Termination rules:
- if the local task signals stop iteration a cancel signal is
relayed to the remote task indicating to stop streaming
- if the remote task signals the end of a stream, raise a
``StopAsyncIteration`` to terminate the local ``async for``
def context(func: Callable) -> Callable:
"""Mark an async function as a streaming routine with ``@context``.
"""
def __init__(
self,
ctx: Context,
rx_chan: trio.abc.ReceiveChannel,
portal: 'Portal', # type: ignore # noqa
) -> None:
self._ctx = ctx
self._rx_chan = rx_chan
self._portal = portal
self._shielded = False
# annotate
# TODO: apply whatever solution ``mypy`` ends up picking for this:
# https://github.com/python/mypy/issues/2087#issuecomment-769266912
func._tractor_context_function = True # type: ignore
# delegate directly to underlying mem channel
def receive_nowait(self):
return self._rx_chan.receive_nowait()
async def receive(self):
try:
msg = await self._rx_chan.receive()
return msg['yield']
except KeyError:
# internal error should never get here
assert msg.get('cid'), ("Received internal error at portal?")
# TODO: handle 2 cases with 3.10 match syntax
# - 'stop'
# - 'error'
# possibly just handle msg['stop'] here!
# TODO: test that shows stream raising an expected error!!!
if msg.get('error'):
# raise the error message
raise unpack_error(msg, self._portal.channel)
except (trio.ClosedResourceError, StopAsyncIteration):
# XXX: this indicates that a `stop` message was
# sent by the far side of the underlying channel.
# Currently this is triggered by calling ``.aclose()`` on
# the send side of the channel inside
# ``Actor._push_result()``, but maybe it should be put here?
# to avoid exposing the internal mem chan closing mechanism?
# in theory we could instead do some flushing of the channel
# if needed to ensure all consumers are complete before
# triggering closure too early?
# Locally, we want to close this stream gracefully, by
# terminating any local consumers tasks deterministically.
# We **don't** want to be closing this send channel and not
# relaying a final value to remaining consumers who may not
# have been scheduled to receive it yet?
# lots of testing to do here
# when the send is closed we assume the stream has
# terminated and signal this local iterator to stop
await self.aclose()
raise StopAsyncIteration
except trio.Cancelled:
# relay cancels to the remote task
await self.aclose()
raise
@contextmanager
def shield(
self
) -> Iterator['ReceiveMsgStream']: # noqa
"""Shield this stream's underlying channel such that a local consumer task
can be cancelled (and possibly restarted) using ``trio.Cancelled``.
"""
self._shielded = True
yield self
self._shielded = False
async def aclose(self):
"""Cancel associated remote actor task and local memory channel
on close.
"""
rx_chan = self._rx_chan
if rx_chan._closed:
log.warning(f"{self} is already closed")
return
# stats = rx_chan.statistics()
# if stats.open_receive_channels > 1:
# # if we've been cloned don't kill the stream
# log.debug(
# "there are still consumers running keeping stream alive")
# return
if self._shielded:
log.warning(f"{self} is shielded, portal channel being kept alive")
return
# close the local mem chan
rx_chan.close()
# cancel surrounding IPC context
await self._ctx.cancel()
# TODO: but make it broadcasting to consumers
# def clone(self):
# """Clone this receive channel allowing for multi-task
# consumption from the same channel.
# """
# return ReceiveStream(
# self._cid,
# self._rx_chan.clone(),
# self._portal,
# )
# class MsgStream(ReceiveMsgStream, trio.abc.Channel):
# """
# Bidirectional message stream for use within an inter-actor actor
# ``Context```.
# """
# async def send(
# self,
# data: Any
# ) -> None:
# await self._ctx.chan.send({'yield': data, 'cid': self._ctx.cid})
sig = inspect.signature(func)
params = sig.parameters
if 'ctx' not in params:
raise TypeError(
"The first argument to the context function "
f"{func.__name__} must be `ctx: tractor.Context`"
)
return func

15
tractor/_trionics.py
View File

@ -252,6 +252,12 @@ async def _open_and_supervise_one_cancels_all_nursery(
f"Waiting on subactors {anursery._children} "
"to complete"
)
# Last bit before first nursery block ends in the case
# where we didn't error in the caller's scope
log.debug("Waiting on all subactors to complete")
anursery._join_procs.set()
except BaseException as err:
# if the caller's scope errored then we activate our
# one-cancels-all supervisor strategy (don't
@ -292,11 +298,6 @@ async def _open_and_supervise_one_cancels_all_nursery(
else:
raise
# Last bit before first nursery block ends in the case
# where we didn't error in the caller's scope
log.debug("Waiting on all subactors to complete")
anursery._join_procs.set()
# ria_nursery scope end
# XXX: do we need a `trio.Cancelled` catch here as well?
@ -357,7 +358,8 @@ async def open_nursery(
try:
if actor is None and is_main_process():
# if we are the parent process start the actor runtime implicitly
# if we are the parent process start the
# actor runtime implicitly
log.info("Starting actor runtime!")
# mark us for teardown on exit
@ -376,7 +378,6 @@ async def open_nursery(
async with _open_and_supervise_one_cancels_all_nursery(
actor
) as anursery:
yield anursery
finally:

54
tractor/log.py
View File

@ -26,35 +26,62 @@ LOG_FORMAT = (
" {thin_white}{filename}{log_color}:{reset}{thin_white}{lineno}{log_color}"
" {reset}{bold_white}{thin_white}{message}"
)
DATE_FORMAT = '%b %d %H:%M:%S'
LEVELS = {
'GARBAGE': 1,
'TRACE': 5,
'PROFILE': 15,
'RUNTIME': 500,
'QUIET': 1000,
'TRANSPORT': 5,
'RUNTIME': 15,
'PDB': 500,
}
STD_PALETTE = {
'CRITICAL': 'red',
'ERROR': 'red',
'RUNTIME': 'white',
'PDB': 'white',
'WARNING': 'yellow',
'INFO': 'green',
'RUNTIME': 'white',
'DEBUG': 'white',
'TRACE': 'cyan',
'GARBAGE': 'blue',
'TRANSPORT': 'cyan',
}
BOLD_PALETTE = {
'bold': {
level: f"bold_{color}" for level, color in STD_PALETTE.items()}
}
class StackLevelAdapter(logging.LoggerAdapter):
def transport(
self,
msg: str,
) -> None:
return self.log(5, msg)
def runtime(
self,
msg: str,
) -> None:
return self.log(15, msg)
def pdb(
self,
msg: str,
) -> None:
return self.log(500, msg)
def get_logger(
name: str = None,
_root_name: str = _proj_name,
) -> logging.LoggerAdapter:
'''Return the package log or a sub-log for `name` if provided.
) -> StackLevelAdapter:
'''Return the package log or a sub-logger for ``name`` if provided.
'''
log = rlog = logging.getLogger(_root_name)
@ -71,13 +98,14 @@ def get_logger(
# add our actor-task aware adapter which will dynamically look up
# the actor and task names at each log emit
logger = logging.LoggerAdapter(log, ActorContextInfo())
logger = StackLevelAdapter(log, ActorContextInfo())
# additional levels
for name, val in LEVELS.items():
logging.addLevelName(val, name)
# ex. create ``logger.trace()``
setattr(logger, name.lower(), partial(logger.log, val))
# ensure customs levels exist as methods
assert getattr(logger, name.lower()), f'Logger does not define {name}'
return logger

48
tractor/msg.py
View File

@ -1,9 +1,13 @@
"""
Messaging pattern APIs and helpers.
NOTE: this module is likely deprecated by the new bi-directional streaming
support provided by ``tractor.Context.open_stream()`` and friends.
"""
import inspect
import typing
from typing import Dict, Any, Set, Callable
from typing import Dict, Any, Set, Callable, List, Tuple
from functools import partial
from async_generator import aclosing
@ -20,7 +24,7 @@ log = get_logger('messaging')
async def fan_out_to_ctxs(
pub_async_gen_func: typing.Callable, # it's an async gen ... gd mypy
topics2ctxs: Dict[str, set],
topics2ctxs: Dict[str, list],
packetizer: typing.Callable = None,
) -> None:
"""Request and fan out quotes to each subscribed actor channel.
@ -34,24 +38,27 @@ async def fan_out_to_ctxs(
async for published in pub_gen:
ctx_payloads: Dict[str, Any] = {}
ctx_payloads: List[Tuple[Context, Any]] = []
for topic, data in published.items():
log.debug(f"publishing {topic, data}")
# build a new dict packet or invoke provided packetizer
if packetizer is None:
packet = {topic: data}
else:
packet = packetizer(topic, data)
for ctx in topics2ctxs.get(topic, set()):
ctx_payloads.setdefault(ctx, {}).update(packet),
for ctx in topics2ctxs.get(topic, list()):
ctx_payloads.append((ctx, packet))
if not ctx_payloads:
log.debug(f"Unconsumed values:\n{published}")
# deliver to each subscriber (fan out)
if ctx_payloads:
for ctx, payload in ctx_payloads.items():
for ctx, payload in ctx_payloads:
try:
await ctx.send_yield(payload)
except (
@ -60,15 +67,24 @@ async def fan_out_to_ctxs(
ConnectionRefusedError,
):
log.warning(f"{ctx.chan} went down?")
for ctx_set in topics2ctxs.values():
ctx_set.discard(ctx)
for ctx_list in topics2ctxs.values():
try:
ctx_list.remove(ctx)
except ValueError:
continue
if not get_topics():
log.warning(f"No subscribers left for {pub_gen}")
break
def modify_subs(topics2ctxs, topics, ctx):
def modify_subs(
topics2ctxs: Dict[str, List[Context]],
topics: Set[str],
ctx: Context,
) -> None:
"""Absolute symbol subscription list for each quote stream.
Effectively a symbol subscription api.
@ -77,7 +93,7 @@ def modify_subs(topics2ctxs, topics, ctx):
# update map from each symbol to requesting client's chan
for topic in topics:
topics2ctxs.setdefault(topic, set()).add(ctx)
topics2ctxs.setdefault(topic, list()).append(ctx)
# remove any existing symbol subscriptions if symbol is not
# found in ``symbols``
@ -85,10 +101,14 @@ def modify_subs(topics2ctxs, topics, ctx):
for topic in filter(
lambda topic: topic not in topics, topics2ctxs.copy()
):
ctx_set = topics2ctxs.get(topic)
ctx_set.discard(ctx)
ctx_list = topics2ctxs.get(topic)
if ctx_list:
try:
ctx_list.remove(ctx)
except ValueError:
pass
if not ctx_set:
if not ctx_list:
# pop empty sets which will trigger bg quoter task termination
topics2ctxs.pop(topic)
@ -256,7 +276,7 @@ def pub(
respawn = True
finally:
# remove all subs for this context
modify_subs(topics2ctxs, (), ctx)
modify_subs(topics2ctxs, set(), ctx)
# if there are truly no more subscriptions with this broker
# drop from broker subs dict

2
tractor/testing/_tractor_test.py
View File

@ -78,7 +78,7 @@ def tractor_test(fn):
else:
# use implicit root actor start
main = partial(fn, *args, **kwargs),
main = partial(fn, *args, **kwargs)
return trio.run(main)
# arbiter_addr=arb_addr,