Been meaning to do this forever and a recent test hang finally drove me
to it Bp
Like it sounds, adopt the "cancel-status" properties on `ActorNursery`
use already on our `Context` and derived from `trio.CancelScope`:
- add new private `._cancel_called` (set in the head of `.cancel()`)
& `._cancelled_caught` (set in the tail) instance vars with matching
read-only `@properties`.
- drop the instance-var and instead delegate a `.cancelled: bool`
property to `._cancel_called` and add a usage deprecation warning
(since removing it breaks a buncha tests).
As mentioned in prior testing commit, it can cause the worst kind of
hangs, the SIGINT ignoring kind.. Pretty sure there was never any reason
outside some esoteric multi-actor debugging case, and pretty sure that
already was solved?
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.
- drop the (never/un)used `.get_chans()`.
- add #TODO for factoring many methods into a new `.rpc`-subsys/pkg
primitive, like an `RPCMngr/Server` type eventually.
- add todo to maybe mv `.get_parent()` elsewhere?
- move masked `._hard_mofo_kill()` to bottom.
Mostly just multi-line code styling again: always putting standalone
`'f\n'` on separate LOC so it reads like it renders to console. Oh and
and a level drop to `.runtime()` for rx-msg reports.
Again using `Channel.aid.reprol()`, `.devx.pformat.nest_from_op()` and
converting to multi-line code style an ' for str-report-contents. Tweak
some imports to sub-mod level as well.
Again for nicer console logging. Also fix a double `req_chan` arg bug
when passed to `_invoke` in the `self.cancel()` rt-ep; don't update the
`kwargs: dict` just merge in `req_chan` input at call time.
Including a new one-line `_shutdown_msg: str` which we mod-var-set for
testing usage and some denoising at `.info()` level. Adjust `Actor()`
instantiating input to the new `.registry_addrs` wrapped addrs property.
Namely inside various bootup-sequences in `._root` and `._runtime`
particularly in the root actor to support both better tpt-address
denoting in our logging and as part of clarifying logic around setting
the root's registry addresses which is soon to be much better factored
out of the core and into an explicit subsystem + API.
Some `_root.open_root_actor()` deats,
- set `registry_addrs` to a new `uw_reg_addrs` (uw: unwrapped) to be
more explicit about wrapped addr types thoughout.
- instead ensure `registry_addrs` are the wrapped types and pass down
into the root `Actor` singleton-instance.
- factor the root-actor check + rt-vars update (updating the `'_root_addrs'`)
out of `._runtime.async_main()` into this fn.
- as previous, set `trans_bind_addrs = uw_reg_addrs` in unwrapped form since it will
be passed down both through rt-vars as `'_root_addrs'` and to
`._runtim.async_main()` as `accept_addrs` (which is then passed to the
IPC server).
- adjust/simplify much logging.
- shield the `await actor.cancel(None) # self cancel` to avoid any
finally-footguns.
- as mentioned convert the
For `_runtime.async_main()` tweaks,
- expect `registry_addrs: list[Address]|None = None` with appropriate
unwrapping prior to setting both `.reg_addrs` and the equiv rt-var.
- add a new `.registry_addrs` prop for the wrapped form.
- convert a final loose-eg for the `service_nursery` to use
`collapse_eg()`.
- simplify teardown report logging.
Mostly adjusting indentation, noise level, and clarity via `.pformat()`
tweaks more general use of `.devx.pformat.nest_from_op()`.
Specific impl deats,
- use `pformat.ppfmt()/`nest_from_op()` more seriously throughout
`._server`.
- add a `._server.Endpoint.pformat()`.
- add `._server.Server.len_peers()` and `.repr_state()`.
- polish `Server.pformat()`.
- drop some redundant `log.runtime()`s from `._serve_ipc_eps()` instead
leaving-them-only/putting-them in the caller pub meth.
- `._tcp.start_listener()` log the bound addr, not the input (which may
be the 0-port.
- only generate a repr in `.from_addr()` when log level is >= 'runtime'.
|_ add a todo about supporting this optimization more generally on our
adapter.
- fix `Channel.pformat()` to show unknown peer field line fmt correctly.
- add a `Channel.maddr: str` which just delegates directly to the
`._transport` like other pass-thru property fields.
To start trying out,
- using in the `Start`-msg handler-block to repr the msg coming
*from* a `repr(Channel)` using '<=)` sclang op.
- for a completed RPC task in `_invoke_non_context()`.
- for the msg loop task's termination report.
Such as the `MsgTransport.stream` and `.drain` attrs since they're
rarely that important at the chan level. Also start adopting
a `.<attr>=` style for actual attrs of the type versus a `<name>:
` style for meta-field info lines.
To simplify `.pformat()` output when the new `privates: bool` is unset
(the default) this adds new public attrs to wrap an actor's
cancellation status as well as provide a `.repr_state: str` (similar to
our equiv on `Context`). Rework `.pformat()` to render a much simplified
repr using all these new refinements.
Further, port the `.cancel()` method to use `.msg.types.Aid` for all
internal `requesting_uid` refs (now renamed with `_aid`) and in all
called downstream methods.
New cancel-state iface deats,
- rename `._cancel_called_by_remote` -> `._cancel_called_by` and expect
it to be set as an `Aid`.
- add `.cancel_complete: bool` which flags whether `.cancel()` ran to
completion.
- add `.cancel_called: bool` which just wraps `._cancel_called` (and
which likely will just be dropped since we already have
`._cancel_called_by`).
- add `.cancel_caller: Aid|None` which wraps `._cancel_called_by`.
In terms of using `Aid` in cancel methods,
- rename vars with `_aid` suffix in `.cancel()` (and wherever else).
- change `.cancel_rpc_tasks()` input param to `req_aid: msgtypes.Aid`.
- do the same for `._cancel_task()` and (for now until we adjust its
internals as well) use the `Aid.uid` remap property when assigning
`Context._canceller`.
- adjust all log msg refs to match obvi.
Providing the legacy `.uid -> tuple` style id (since still used for the
`Actor._contexts` table) and a `repr-one-line` method `.reprol() -> str`
for rendering a compact unique actor ID summary (useful in
logging/.pformat()s at the least).
I dunno what exactly I was thinking but we definitely don't want to
**ever** raise from the original exc-group, instead always raise from
any original `.__cause__` to be consistent with the embedded src-error's
context.
Also, adjust `maybe_collapse_eg()` to return `False` in the non-single
`.exceptions` case, again don't know what I was trying to do but this
simplifies caller logic and the prior return-semantic had no real
value..
This fixes some final usage in the runtime (namely top level nursery
usage in `._root`/`._runtime`) which was previously causing test suite
failures prior to this fix.
Seems to cause the following test suites to fail however..
- 'test_advanced_faults.py::test_ipc_channel_break_during_stream'
- 'test_advanced_faults.py::test_ipc_channel_break_during_stream'
- 'test_clustering.py::test_empty_mngrs_input_raises'
Also tweak some ctxc request logging content.
That is just throughout the core library, not the tests yet. Again, we
simply change over to using our (nearly equivalent?)
`.trionics.collapse_eg()` in place of the already deprecated
`strict_exception_groups=False` flag in the following internals,
- the conc-fan-out tn use in `._discovery.find_actor()`.
- `._portal.open_portal()`'s internal tn used to spawn a bg rpc-msg-loop
task.
- the daemon and "run-in-actor" layered tn pair allocated in
`._supervise._open_and_supervise_one_cancels_all_nursery()`.
The remaining loose-eg usage in `._root` and `._runtime` seem to be
necessary to keep the test suite green?? For the moment these are left
out.
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.
To resolve the recently added and failing
`test_remote_exc_relay::test_unmasked_remote_exc`: never allow
`trio.Cancelled` to mask an underlying user-code exception, ever.
Our first real-world (runtime internal) use case for the new
`.trionics.maybe_raise_from_masking_exc()` such that the failing
test now passes with an properly relayed remote RTE unmasking B)
Details,
- flip the `Context._scope_nursery` to the default strict-eg behaviour
and instead stack its outer scope with a `.trionics.collapse_eg()`.
- wrap the inner-most scope (after `msgops.maybe_limit_plds()`) with
a `maybe_raise_from_masking_exc()` to ensure user-code errors are
never masked by `trio.Cancelled`s.
Some err-reporting refinement,
- always capture any `scope_err` from the entire block for debug
purposes; report it in the `finally` block's log.
- always capture any suppressed `maybe_re`, output from
`ctx.maybe_raise()`, and `log.cancel()` report it.
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?
To handle captured non-egs (when the now optional `tn` isn't provided)
as well as yield up a `BoxedMaybeException` which contains any detected
and un-masked `exc_ctx` as its `.value`.
Also add some additional tooling,
- a `raise_unmasked: bool` toggle for when the caller just wants to
report the masked exc and not raise-it-in-place of the masker.
- `extra_note: str` which by default is tuned to the default
`unmask_from = (trio.Cancelled,)` but which can be used to deliver
custom exception msg content.
- `always_warn_on: tuple[BaseException]` which will always emit
a warning log of what would have been the raised-in-place-of
`ctx_exc`'s msg for special cases where you want to report
a masking case that might not be otherwise noticed by the runtime
(cough like a `Cancelled` masking another `Cancelled) but which
you'd still like to warn the caller about.
- factor out the masked-`ext_ctx` predicate logic into
a `find_masked_excs()` and also use it for non-eg cases.
Still maybe todo?
- rewrapping multiple masked sub-excs in an eg back into an eg? left in
#TODOs and a pause-point where applicable.
Tyler Goodlet
Bd