By spawning an actor task that immediately shuts down the transport
server and then sleeps, verify that attempting to connect via the
`._discovery.find_actor()` helper delivers `None` for the `Portal`
value.
Relates to #184 and #216
While working on a fix to the hang case found from
`test_cancel_ctx_with_parent_side_entered_in_bg_task` an initial
solution caused this test to hang indefinitely; solve it with a small
wrapping `_main()` + `trio.fail_after()` entrypoint.
Further suite refinements,
- move the top-most `try:`->`else:` block
- toss in a masked base-exc block for tracing unexpected
`ctx.wait_for_result()` outcomes.
- tweak the `raise_sub_spawn_error_after` to be an optional `float`
which scales the `rng_seed: int = 50` msg counter to
`tell_little_bro()` so that the abs value to the `range()` can be
changed.
Such that when `maybe_context.cancel()` is not called (explicitly) and
only the subactor is cancelled by its parent we expect to see a ctxc
raised both from any call to `Context.wait_for_result()` and out of
the `Portal.open_context()` scope, up to the `trio.run()`.
Deats,
- obvi call-n-catch the ctxc (in scope) for the oob-only
subactor-cancelled case.
- add branches around `trio.run()` entry to match.
Discovered while writing a `@context` sanity test to verify unmasker
ignore-cases support. Masked code is due to the process of finding the
minimal example causing the original hang discovered in the original
examples script. Details are in the test-fn doc strings and surrounding
comments; more refinement and cleanup coming obviously.
Also moved over the self-cancel todos from the inter-peer tests module.
Demonstrating the guilty `trio.Lock.acquire()` impl which puts
a checkpoint inside its `trio.WouldBlock` handler and which will always
appear to mask the "sync path" case on (graceful) cancellation.
This first script draft demos the issue from within a `tractor.context`
ep bc that's where it was orig discovered, however i'm going to factor
out the `tractor` code and instead just use
a `.trionics.maybe_raise_from_masking_exc()` to demo its low-level
ignore-case feature.
Further, this script exposed a previously unhandled remote graceful
cancellation case which hangs:
- parent actor spawns child and opens a >1 ctxs with it,
- the parent then OoB (out-of-band) cancels the child actor (with
`Portal.cancel_actor()`),
- since the open ctxs raise a ctxc with a `.canceller == parent.uid` the
`Context._is_self_cancelled()` will eval `True`,
- the `Context._scope` will NOT be cancelled in
`._maybe_cancel_and_set_remote_error()` resulting in any bg-task which
is waiting on a `Portal.open_context()` to not be cancelled/unblocked.
So my plan is to factor this ^^ scenario into a standalone unit test
as well as another test which consumes from al low-level `trio`-only
version of **this** script-scenario to sanity check the interaction
of the unmasker-with-ignore-cases usage implicitly around a ctx ep.
Call it `test_trioisms::test_unmask_aclose_as_checkpoint_on_aexit` and
parametrize all script-mod`.main()` toggles including `.xfails()` for
the `raise_unmasked=False` cases.
Including all caller usage throughout. Moving to a non-`except*` impl
means it's never needed as a signal from the caller - we can just catch
the beg outright (like we should have always been doing)..
Such that we audit the `shield=root_tn.cancel_scope.cancel_called,`
passed to `await debug._maybe_enter_pm()` in the `open_root_actor()`
exit handler block.
Verifying that if any exc is raised pre `chan.send_nowait()` (our
currentlly shite version of a `chan.started()`) then that exc is indeed
raised through on the `trio`-parent task side. This case was reproduced
from a `piker.brokers.ib` issue with a similar embedded
`.trionics.maybe_open_context()` call.
Deats,
- call the suite `test_aio_side_raises_before_started`.
- mk the `@context` simply `maybe_open_context(acm_func=open_channel_from)`
with a `target=raise_before_started` which,
- simply sleeps then immediately raises a RTE.
- expect the RTE from the aio-child-side to propagate all the way up to
the root-actor's task right up through the `trio.run()`.
Since it's merely a local-file-sys subdirectory and there should be no
reason file creation conflicts with other bind spaces.
Also add 2 test suites to match,
- `tests/ipc/test_each_tpt::test_uds_bindspace_created_implicitly` to
verify the dir creation when DNE.
- `..test_uds_double_listen_raises_connerr` to ensure a double bind
raises a `ConnectionError` from the src `OSError`.
Call it `test_lock_not_corrupted_on_fast_cancel()` and includes
a detailed doc string to explain. Implemented it "cleverly" by having
the target `@acm` cancel its parent nursery after a peer, cache-hitting
task, is already waiting on the task mutex release.
Here I was thinking the bcaster (usage) maybe required a rework but,
NOPE it's just bc a checkpoint was needed in the parent task owning the
`tn` which spawns `get_sub_and_pull()` tasks to ensure the bg allocated
`an`/portal is eventually cancel-called..
Ah well, at least i started a patch for `MsgStream.subscribe()` to make
it multicast revertible.. XD
Anyway, I tossed in some checks & notes related to all that unnecessary
effort since I do think i'll move forward implementing it:
- for the `cache_hit` case always verify that the `bcast` clone is
unregistered from the common state subs after
`.subscribe().__aexit__()`.
- do a light check that the implicit `MsgStream._broadcaster` is always
the only bcrx instance left-leaked into that state.. that is until
i get the proper de-allocation/reversion from multicast -> unicast
working.
- put in mega detailed note about the required parent-task checkpoint.
Since I recently discovered a very subtle race-case that can sometimes
cause the suite to hang, seemingly due to the `an: ActorNursery`
allocated *behind* the `.trionics.maybe_open_context()` usage; this can
result in never cancelling the 'streamer' subactor despite the `main()`
timeout-guard?
This led me to dig in and find that the underlying issue was 2-fold,
- our `BroadcastReceiver` termination-mgmt semantics in
`MsgStream.subscribe()` can result in the first subscribing task to
always keep the `MsgStream._broadcaster` instance allocated; it's
never `.aclose()`ed, which makes it tough to determine (and thus
trace) when all subscriber-tasks are actually complete and
exited-from-`.subscribe()`..
- i was shield waiting `.ipc._server.Server.wait_for_no_more_peers()` in
`._runtime.async_main()`'s shutdown sequence which would then compound
the issue resulting in a SIGINT-shielded hang.. the worst kind XD
Actual changes here are just styling, printing, and some mucking with
passing the `an`-ref up to the parent task in the root-actor where i was
doing a conditional `ActorNursery.cancel()` to mk sure that was actually
the problem. Presuming this is fixed the `.pause()` i left unmasked
should never hit.
Was failing due to the `.fail_after()` timeout being *too short* and
somehow the new interplay of that with strict-exception groups resulting
in the `TooSlowError` never raising but instead an eg with the embedded
`AssertionError`?? I still don't really get it honestly..
I've written up lengthy notes around the different `delay` settings that
can be used to see the diff outcomes, the failing case being the one
i still don't really grok and think is justification for `trio` to
bubble inner `Cancelled`s differently possibly?
For now i've included the original failing case as an `xfail`
parametrization for now which will hopefully drive a follow lowlevel
`trio` test in `test_trioisms`!
Namely `test_empty_mngrs_input_raises()` was failing due to
lazy-iterator use as input to `mngrs` which i guess i added support for
a while back (by it doing a `list(mngrs)` internally)? So just change it
to `gather_contexts(mngrs=())` and also tweak the `trio.fail_after(3)`
since it appears that the prior 1sec was causing
too-fast-of-a-cancellation (before the cluster fully spawned) and thus
the expected `ValueError` never to show..
Also, mask the `tractor.trionics.collapse_eg()` usage (again?) in
`open_actor_cluster()` since it seems unnecessary.
Seems that the way the actor-nursery interacts with the
`.trionics.gather_contexts()` API on cancellation makes our
`.trionics.collapse_eg()` not work as intended?
I need to dig into how `ActorNursery.cancel()` and `.__aexit__()` might
be causing this discrepancy..
Consider this a commit-of-my-index type save for rn.
Since it's for beg filtering, the current impl should be renamed anyway;
it's not just for filtering cancelled excs.
Deats,
- added a real doc string, links to official eg docs and fixed the
return typing.
- adjust all internal imports to match.
Namely that the more common-and-pertinent case is when
a `@context`-ep-fn contains the `finally`-footgun but without
a surrounding embedded `tn` (which currently still requires its own
scope embedded `trionics.maybe_raise_from_masking_exc()`) which can't
be compensated-for by `._rpc._invoke()` easily. Instead the test is
composed where the `._invoke()`-internal `tn` is the machinery being
addressed in terms of masking user-code excs with `trio.Cancelled`.
Deats,
- rename the test -> `test_unmasked_remote_exc` to reflect what the
runtime should actually be addressing/solving.
- drop the embedded `tn` from `sleep_n_chkpt_in_finally()` (for now)
since that case can't currently easily be addressed without the user
code using its own `trionics.maybe_raise_from_masking_exc()` inside
the nursery scope.
- as such drop all `tn` related params/logic/usage from the ep.
- add in a `Cancelled` handler block which checks for RTE masking and
always prints the occurrence loudly.
Follow up,
- obvi this suite will currently fail until the appropriate adjustment
is made to `._rpc._invoke()` to do the unmasking; coming next.
- we probably still need a case with an embedded user `tn` where if
the default strict-eg mode is used then a ctxc from the parent might
cause a non-graceful `Context.cancel()` outcome?
|_since the embedded user-`tn` will raise
`ExceptionGroup[trio.Cancelled]` upward despite the parent nursery's
scope being the canceller, or will a `collapse_eg()` inside the
`._invoke()` scope handle this as well?
Deats are documented within, but basically a subtlety we already track
with `trio`'s masking of excs by a checkpoint-in-`finally` can cause
compounded issues with our `@context` endpoints, mostly in terms of
remote error and cancel-ack relay semantics.
Nicely nailing 2 birds by leveraging the new `repl_fixture` support to
actually avoid use of a `pexpect`-style test B)
Functionality audit summary,
- ensures `open_crash_handler() as bxerr:` adheres to,
- `raise_on_exit` semantics including only raising from a list of exc-types,
- `repl_fixture` setup/teardown invocation and that `yield False` blocks REPL
interaction,
- delivering a `BoxedMaybeException` with the correct state set post
crash.
- all the above outside the actor-runtime existing.
Also luckily enough, this seems to have found a bug for which a fix is
coming right up!
It's been in the debug scripts quite a while without a wrapping test and
will be,
- only the 2nd such REPL test which uses a lower-level `@context` ep-API
- the first official and explicit use of `enable_transports=['uds']`
a suite.
Deats,
- flip to 'uds' tpt and 'devx' level logging in the script.
- add a new 2-case suite `test_ctxep_pauses_n_maybe_ipc_breaks` which
validates both the quit-early (via `BdbQuit`) and
channel-dropped-need-to-ctlc cases from a single test fn.
If the underlying example script fails (say due to a console output
pattern-mismatch, `AssertionError`) the `pexpect` managed subproc with
a `debug_mode=True` crash-handling-REPL engaged will ofc *not terminate*
due to any SIGINT sent by the test harnesss (since we shield from it as
part of normal sub-actor debugger operation). So instead always send
a 'continue' cmd to the active `PdbREPL`'s stdin so it deactivates and
allows the py-script-process to raise and terminate, unblocking the
`pexpect.spawn`'s internal subproc joiner (which would otherwise hang
without manual intervention, blocking downstream tests..).
Also, use the new `PexpectSpawner` type alias after actually importing
future annots.. XD
Such that we can more easily annotate any consumer test's of our
`.tests.devx.conftest.spawn()` fixture which delivers a closure which, when
called in a test fn body, transitively sub-invokes:
`pytest.Pytester.spawn()` -> `pexpect.spawn()`
IMO Expecting `Callable[[str], pexpect.pty_spawn.spawn]]` to be used all
over is a bit too.. verbose?
Like it sounds, verifying that when that param is passed to the runtime
startup eps (`.open_root_actor()/.open_nursery()`), the appropriate
tpt-protocol is deployed for IPC (both the server and bound endpoints)
in both the root and any sub-actors (as passed down from rent to child
via the `.msg.types.SpawnSpec`).
We already have the `.ipc` sub-pkg name so it seems a bit
redundant/noisy for a namespace path Bp
Leave an alias for the `Server` rn since it's already used in a few
other internal mods.. will likely rename later if everyone is cool with
it..
Namely any CLI driven runtime-config fixtures such as,
- `--spawn-backend` and `start_method`,
- `--tpdb` and `debug_mode`,
- `--tpt-proto` and `tpt_protos`/`tpt_proto`,
- `reg_addr` as driven by the above.
This moves all fixtures and necessary hook funcs (CLI parsing,
configuring and test-gen) to the `._testing.pytest` module and thus
allows any dependent project to leverage these fixtures in their own
test suites after pointing to that plugin mod using,
```python
# conftest.py
pytest_plugins: tuple[str] = (
"tractor._testing.pytest",
)
```
Also, add a new `._testing.addr` helper mod which now contains
a factored `get_rando_addr()` helper for creating test-sesh unique
tpt-specific registry (or other) IPC endpoint addrs.
For now it just boots a server, parametrized over all tpt-protos, sin
any actor runtime bootup. Obvi the future todo is ensuring it all works
with a client connecting via the equivalent lowlevel
`.ipc._chan._connect_chan()` API(s).
Namely while what I was actually trying to solve was why
`TransportClosed` was getting raised from `Portal.cancel_actor()` but
still useful edge case auditing either way. Also opts into the
`debug_mode` fixture with apprope timeout adjustment B)
Tyler Goodlet