For comparing a `msgspec.Struct` against an input `dict` presumably to
be used as input for struct instantiation. The main diff with
`.__sub__()` is that non-existing fields on either are reported
(loudly).
Such that maybe we can eventually offer a nicer higher-level API which
implements much of the boilerplate required by `msgspec` (like
type-matched branching to serialization logic) via a type-table
interface or something?
Not sure if the idea is that useful so leaving it all as TODOs for now
obviously.
Mostly fixing edge cases with `asyncio` and/or bg threads where the
`.repl_release: trio.Event` needs to be used from the main `trio`
thread OW confusing-but-valid teardown tracebacks can show under various
races.
Also improve,
- log reporting for such internal bugs to make them more obvious on
console via `log.exception()`.
- only restore the SIGINT handler when runtime is (still) active.
- reporting when `tractor.pause(shield=True)` should be used and
unhiding the internal frames from the tb in that case.
- for `pause_from_sync()` some deep fixes..
|_add a `allow_no_runtime: bool = False` flag to allow
**not** requiring the actor runtime to be active.
|_fix the `greenback` case-branch to only trigger on `not
is_trio_thread`.
|_add a scope-global `repl_owner: Task|Thread|None = None` to
avoid ref errors..
As in whenever `Context.cancel()` is not (runtime internally) called
(i.e. `._cancel_called` is not set), we can attempt to detect the parent
`trio` nursery/cancel-scope that is the source. Emit the report with
a `.cancel()` level and attempt to repr in "sclang" form as well as
unhide the stack frame for debug/traceback-in.
Various `try`/`except` blocks around external APIs that raise when not
running inside an `tractor` and/or some async framework (mostly to avoid
too-late/benign error tbs on certain classes of actor tree teardown):
- for the `log.pdb()` prompts emitted before REPL console entry.
- inside `DebugStatus.is_main_trio_thread()`'s call to `sniffio`.
- in `_post_mortem()` by catching `NoRuntime` when called from a thread
still active after the `.open_root_actor()` has already exited.
Also,
- create a dedicated `DebugStateError` for raising instead of `assert`s
when we have actual debug-request inconsistencies (as seem to be most
likely with bg thread usage of `breakpoint()`).
- show the `open_crash_handler()` frame on `bdb.BdbQuit` (for now?)
Since it seems that `pdbp.xpm()` can sometimes lose the up-stack
traceback info/frames? Not sure why but ours seems to work just fine
from a `asyncio`-handler in `modden`'s use of `i3ipc` B)
Also call `DebugStatus.shield_sigint()` from `pause_from_sync()` in the
infected-`asyncio` case to get the same shielding behaviour as in all
other usage!
Mostly due to magic from @oremanj where we slap in a little bit of
`.from_asyncio`-type stuff to run a `trio`-task from `asyncio.Task`
code!
I'm not gonna go into tooo too much detail but basically the primary
thing needed was a way to (blocking-ly) invoke a `trio.lowlevel.Task`
from an `asyncio` one (which we now have with a new
`run_trio_task_in_future()` thanks to draft code from the aforementioned
jefe) which we now invoke from a dedicated aio case-branch inside
`.devx._debug.pause_from_sync()`. Further include a case inside
`DebugStatus.release()` to handle using the same func to set the
`repl_release: trio.Event` from the aio side when releasing the REPL on
exit cmds.
Prolly more refinements to come ;{o
Just like we've started doing throughout the rest of the actor runtime
for reporting (and where "sclang" = "structured conc (s)lang", our
little supervision-focused operations syntax i've been playing with in
log msg content).
Further tweaks:
- report the `trio_done_fute` alongside the `main_outcome` value.
- add a todo list for supporting `greenback` for pause points.
The reason for this "duplication" with the `--asyncio` CLI flag (passed
to the child during spawn) is 2-fold:
- allows verifying inside `Actor._from_parent()` that the `trio` runtime was
started via `.start_guest_run()` as well as if the
`Actor._infected_aio` spawn-entrypoint value has been set (by the
`._entry.<spawn-backend>_main()` whenever `--asyncio` is passed)
such that any mismatch can be signaled via an `InternalError`.
- enables checking the `._state._runtime_vars['_is_infected_aio']` value
directly (say from a non-actor/`trio`-thread) instead of calling
`._state.current_actor(err_on_no_runtime=False)` in certain edge
cases.
Impl/testing deats:
- add `._state._runtime_vars['_is_infected_aio'] = False` default.
- raise `InternalError` on any `--asyncio`-flag-passed vs.
`_runtime_vars`-value-relayed-from-parent inside
`Actor._from_parent()` and include a `Runner.is_guest` assert for good
measure B)
- set and relay `infect_asyncio: bool` via runtime-vars to child in
`ActorNursery.start_actor()`.
- verify `actor.is_infected_aio()`, `actor._infected_aio` and
`_state._runtime_vars['_is_infected_aio']` are all set in test suite's
`asyncio_actor()` endpoint.
By re-purposing our `pexpect`-based console matching with a new
`debugging/shield_hang_in_sub.py` example, this tests a few "hanging
actor" conditions more formally:
- that despite a hanging actor's task we can dump
a `stackscope.extract()` tree on relay of `SIGUSR1`.
- the actor tree will terminate despite a shielded forever-sleep by our
"T-800" zombie reaper machinery activating and hard killing the
underlying subprocess.
Some test deats:
- simulates the expect actions of a real user by manually using
`os.kill()` to send both signals to the actor-tree program.
- `pexpect`-matches against `log.devx()` emissions under normal
`debug_mode == True` usage.
- ensure we get the actual "T-800 deployed" `log.error()` msg and
that the actor tree eventually terminates!
Surrounding (re-org/impl/test-suite) changes:
- allow disabling usage via a `maybe_enable_greenback: bool` to
`open_root_actor()` but enable by def.
- pretty up the actual `.devx()` content from `.devx._stackscope`
including be extra pedantic about the conc-primitives for each signal
event.
- try to avoid double handles of `SIGUSR1` even though it seems the
original (what i thought was a) problem was actually just double
logging in the handler..
|_ avoid double applying the handler func via `signal.signal()`,
|_ use a global to avoid double handle func calls and,
|_ a `threading.RLock` around handling.
- move common fixtures and helper routines from `test_debugger` to
`tests/devx/conftest.py` and import them for use in both test mods.
The final issue was making sure we do the same thing on ctl-c/SIGINT
from the user. That is, if there's already a bg-thread in REPL, we
`log.pdb()` about SIGINT shielding and re-draw the prompt; the same UX
as normal actor-runtime-task behaviour.
Reasons this wasn't workin.. and the fix:
- `.pause_from_sync()` was overriding the local `repl` var with `None`
delivered by (transitive) calls to `_pause(debug_func=None)`.. so
remove all that and only assign it OAOO prior to thread-type case
branching.
- always call `DebugStatus.shield_sigint()` as needed from all requesting
threads/tasks:
- in `_pause_from_bg_root_thread()` BEFORE calling `._pause()` AND BEFORE
yielding back to the bg-thread via `.started(out)` to ensure we're
definitely overriding the handler in the `trio`-main-thread task
before unblocking the requesting bg-thread.
- from any requesting bg-thread in the root actor such that both its
main-`trio`-thread scheduled task (as per above bullet) AND it are
SIGINT shielded.
- always call `.shield_sigint()` BEFORE any `greenback._await()` case
don't entirely grok why yet, but it works)?
- for `greenback._await()` case always set `bg_task` to the current one..
- tweaks to the `SIGINT` handler, now renamed `sigint_shield()` so as
not to name-collide with the methods when editor-searching:
- always try to `repr()` the REPL thread/task "owner" as well as the
active `PdbREPL` instance.
- add `.devx()` notes around the prompt flushing deats and comments
for any root-actor-bg-thread edge cases.
Related/supporting refinements:
- add `get_lock()`/`get_debug_req()` factory funcs since the plan is to
eventually implement both as `@singleton` instances per actor.
- fix `acquire_debug_lock()`'s call-sig-bug for scheduling
`request_root_stdio_lock()`..
- in `._pause()` only call `mk_pdb()` when `debug_func != None`.
- add some todo/warning notes around the `cls.repl = None` in
`DebugStatus.release()`
`test_pause_from_sync()` tweaks:
- don't use a `attach_patts.copy()`, since we always `break` on match.
- do `pytest.fail()` on that ^ loop's fallthrough..
- pass `do_ctlc(child, patt=attach_key)` such that we always match the
the current thread's name with the ctl-c triggered `.pdb()` emission.
- oh yeah, return the last `before: str` from `do_ctlc()`.
- in the script, flip `abandon_on_cancel=True` since when `False` it
seems to cause `trio.run()` to hang on exit from the last bg-thread
case?!?
There's a been a todo for soo long for this XD
Since all `Actor`'s store a set of `._peers` we can try a lookup on that
table as a shortcut before pinging the registry Bo
Impl deats:
- add a new `._discovery.get_peer_by_name()` routine which attempts the
`._peers` lookup by combining a copy of that `dict` + an entry added
for `Actor._parent_chan` (since all subs have a parent and often the
desired contact is just that connection).
- change `.find_actor()` (for the `only_first == True` case),
`.query_actor()` and `.wait_for_actor()` to call the new helper and
deliver appropriate outputs if possible.
Other,
- deprecate `get_arbiter()` def and all usage in tests and examples.
- drop lingering use of `arbiter_sockaddr` arg to various routines.
- tweak the `Actor` doc str as well as some code fmting and a tweak to
the `._stream_handler()`'s initial `con_status: str` logging value
since the way it was could never be reached.. oh and `.warning()` on
any new connections which already have a `_pre_chan: Channel` entry in
`._peers` so we can start minimizing IPC duplications.
In the `drain_to_final_msg()` impl, since a stream terminating
gracefully requires this msg, there's really no reason to `log.cancel()`
about it; go `.runtime()` level instead since we're trying de-noise
under "normal operation".
Also,
- passthrough `hide_tb` to taskc-handler's `ctx.maybe_raise()` call.
- raise `MessagingError` for the `MsgType` unmatched `case _:`.
- detail the doc string motivation a little more.
In `lock_stdio_for_peer()` better internal-error handling/reporting:
- only `Lock._blocked.remove(ctx.cid)` if that same cid was added on
entry to avoid needless key-errors.
- drop all `Lock.release(force: bool)` usage remnants.
- if `req_ctx.cancel()` fails mention it with `ctx_err.add_note()`.
- add more explicit internal-failed-request log messaging via a new
`fail_reason: str`.
- use and use new `x)<=\n|_` annots in any failure logging.
Other cleanups/niceties:
- drop `force: bool` flag entirely from the `Lock.release()`.
- use more supervisor-op-annots in `.pdb()` logging
with both `_pause/crash_msg: str` instead of double '|' lines when
`.pdb()`-reported from `._set_trace()`/`._post_mortem()`.
As per a WIP scribbled out TODO in `._entry.nest_from_op()`, change
a bunch of "supervisor/lifetime mgmt ops" related log messages to
contain some supervisor-annotation "headers" in an effort to give
a terser "visual indication" of how some execution/scope/storage
primitive entity (like an actor/task/ctx/connection) is being operated
on (like, opening/started/closed/cancelled/erroring) from a "supervisor
action" POV.
Also tweak a bunch more emissions to lower levels to reduce noise around
normal inter-actor operations like process and IPC ctx supervision.
To avoid showing lowlevel details of exception handling around the
underlying call to `return await self._ctx._pld_rx.recv_pld(ipc=self)`,
any time a `RemoteActorError` is unpacked (an raised locally) we re-raise
it directly from the captured `src_err` captured so as to present to
the user/app caller-code an exception raised directly from the `.receive()`
frame. This simplifies traceback call-stacks for any `log.exception()`
or `pdb`-REPL output filtering out the lower `PldRx` frames by default.
Since it was all ad-hoc defined inside
`._ipc.MsgpackTCPStream._iter_pkts()` more or less, this starts
formalizing a way for particular transport backends to indicate whether
a disconnect condition should be re-raised in the RPC msg loop and if
not what log level to report it at (if any).
Based on our lone transport currently we try to suppress any logging
noise from ephemeral connections expected during normal actor
interaction and discovery subsys ops:
- any short lived discovery related TCP connects are only logged as
`.transport()` level.
- both `.error()` and raise on any underlying `trio.ClosedResource`
cause since that normally means some task touched transport layer
internals that it shouldn't have.
- do a `.warning()` on anything else unexpected.
Impl deats:
- extend the `._exceptions.TransportClosed` to accept an input log
level, raise-on-report toggle and custom reporting & raising via a new
`.report_n_maybe_raise()` method.
- construct the TCs with inputs per case in (the newly named) `._iter_pkts().
- call ^ this method from the `TransportClosed` handler block inside the
RPC msg loop thus delegating reporting levels and/or raising to the
backend's per-case TC instantiating.
Related `._ipc` changes:
- mask out all the `MsgpackTCPStream._codec` debug helper stuff and drop
any lingering cruft from the initial proto-ing of msg-codecs.
- rename some attrs/methods:
|_`MsgpackTCPStream._iter_packets()` -> `._iter_pkts()` and
`._agen` -> `_aiter_pkts`.
|_`Channel._aiter_recv()` -> `._aiter_msgs()` and
`._agen` -> `_aiter_msgs`.
- add `hide_tb: bool` support to `Channel.send()` and only show the
frame on non-MTEs.
- allow passing and report the lib name (`trio` or `tractor`) from
`maybe_open_nursery()`.
- use `.runtime()` level when reporting `_Cache`-hits in
`maybe_open_context()`.
- tidy up some doc strings.
In case the struct doesn't import a field type (which will cause the
`.pformat()` to raise) just report the issue and try to fall back to the
original `repr()` version.
It's too fragile to put in side core RPC machinery since
`msgspec.Struct` defs can fail if a field type can't be
looked up at creation time (like can easily happen if you
conditionally import using `if TYPE_CHECKING:`)
Also,
- rename `cs` to `rpc_ctx_cs: CancelScope` since it's literally
the wrapping RPC `Context._scope`.
- report self cancellation via `explain: str` and add tail case for
"unknown cause".
- put a ?TODO? around what to do about KBIs if a context is opened
from an `infected_aio`-actor task.
- similar to our nursery and portal add TODO list for moving all
`_invoke_non_context()` content out the RPC core and instead implement
them as `.hilevel` endpoint helpers (maybe as decorators?)which under
neath define `@context`-funcs.
Log-report the different types of actor exit conditions including cancel
via KBI, error or normal return with varying levels depending on case.
Also, start proto-ing out this weird ascii-syntax idea for describing
conc system states and implement the first bit in a `nest_from_op()`
log-message fmter that joins and indents an obj `repr()` with
a tree-like `'>)\n|_'` header.
Since we more or less require it for `tractor.pause_from_sync()` this
refines enable toggles and their relay down the actor tree as well as
more explicit logging around init and activation.
Tweaks summary:
- `.info()` report the module if discovered during root boot.
- use a `._state._runtime_vars['use_greenback']: bool` activation flag
inside `Actor._from_parent()` to determine if the sub should try to
use it and set to `False` if mod-loading fails / not installed.
- expose `maybe_init_greenback()` from `.devx` sugpkg.
- comment out RTE in `._pause()` for now since we already have it in
`.pause_from_sync()`.
- always `.exception()` on `maybe_init_greenback()` import errors to
clarify the underlying failure deats.
- always explicitly report if `._state._runtime_vars['use_greenback']`
was NOT set when `.pause_from_sync()` is called.
Other `._runtime.async_main()` adjustments:
- combine the "internal error call ur parents" message and the failed
registry contact status into one new `err_report: str`.
- drop the final exception handler's call to
`Actor.lifetime_stack.close()` since we're already doing it in the
`finally:` block and the earlier call has no currently known benefit.
- only report on the `.lifetime_stack()` callbacks if any are detected
as registered.
Not sure how I forgot this but, obviously it's correct context-var
semantics to revert the current IPC `Context` (set in the latest
`.open_context()` block) such that any prior instance is reset..
This ensures the sanity `assert`s pass inside
`.msg._ops.maybe_limit_plds()` and just in general ensures for any task
that the last opened `Context` is the one returned from
`current_ipc_ctx()`.
Turns out it does work XD
Prior presumption was from before I had the fute poll-loop so makes
sense we needed more then one sched-tick's worth of context switch vs.
now we can just keep looping-n-pumping as fast possible until the
guest-run's main task completes.
Also,
- minimize the preface commentary (as per todo) now that we have tests
codifying all the edge cases :finger_crossed:
- parameter-ize the pump-loop-cycle delay and default it to 0.
This change is adding commentary about the upcoming API removal and
simplification of nursery + portal internals; no actual code changes are
included.
The plan to (re)move the old RPC methods:
- `ActorNursery.run_in_actor()`
- `Portal.run()`
- `Portal.run_from_ns()`
and any related impl internals out of each conc-primitive and instead
into something like a `.hilevel.rpc` set of APIs which then are all
implemented using the newer and more lowlevel `Context`/`MsgStream`
primitives instead Bo
Further,
- formally deprecate the `Portal.result()` meth for
`.wait_for_result()`.
- only `log.info()` about runtime shutdown in the implicit root case.
Might as well add a public maybe-getter for use on the "parent" side
since it can be handy to check out-of-band cancellation conditions (like
from `Portal.cancel_actor()`).
Buncha bitty tweaks for more easily debugging cancel conditions:
- add a `@.cancel_called.setter` for hooking into `.cancel_called = True`
being set in hard to decipher "who cancelled us" scenarios.
- use a new `self_ctxc: bool` var in `.cancel()` to capture the output
state from `._is_self_cancelled(remote_error)` at call time so it can
be compared against the measured value at crash-time (when REPL-ing it
can often have already changed due to runtime teardown sequencing vs.
the crash handler hook entry).
- proxy `hide_tb` to `.drain_to_final_msg()` from `.wait_for_result()`.
- use `remote_error.sender` attr directly instead of through
`RAE.msgdata: dict` lookup.
- change var name `our_uid` -> `peer_uid`; it's not "ours"..
Other various docs/comment updates:
- extend the main class doc to include some other name ideas.
- change over all remaining `.result()` refs to `.wait_for_result()`.
- doc more details on how we want `.outcome` to eventually signature.
To make the recent set of tests pass this (hopefully) finally solves all
`asyncio` embedded `trio` guest-run abandonment by ensuring we "pump the
event loop" until the guest-run future is fully complete.
Accomplished via simple poll loop of the form `while not
trio_done_fut.done(): await asyncio.sleep(.1)` in the `aio_main()`
task's exception teardown sequence. The loop does a naive 10ms
"pump-via-sleep & poll" for the `trio` side to complete before finally
exiting (and presumably raising) from the SIGINT cancellation.
Other related cleanups and refinements:
- use `asyncio.Task.result()` inside `cancel_trio()` since it also
inline-raises any exception outcome and we can also log-report the
result in non-error cases.
- comment out buncha not-sure-we-need-it stuff in `cancel_trio()`.
- remove the botched `AsyncioCancelled(CancelledError):` idea obvi XD
- comment `greenback` init for now in `aio_main()` since (pretty sure)
we don't ever want to actually REPL in that specific func-as-task?
- always capture any `fute_err: BaseException` from the `main_outcome:
Outcome` delivered by the `trio` side guest-run task.
- add and raise a new super noisy `AsyncioRuntimeTranslationError`
whenever we detect that the guest-run `trio_done_fut` has not
completed before task exit; should avoid abandonment issues ever
happening again without knowing!
Turns out it somehow breaks our `to_asyncio` error relay since obvi
`asyncio`'s runtime seems to specially handle it (prolly via
`isinstance()` ?) and it caused our
`test_aio_cancelled_from_aio_causes_trio_cancelled()` to hang..
Further, obvi `unpack_error()` won't be able to find the type def if not
kept inside `._exceptions`..
So given all that, revert the change/move as well as:
- tweak the aio-from-aio cancel test to timeout.
- do `trio.sleep()` conc with any bg aio task by moving out nursery
block.
- add a `send_sigint_to: str` parameter to
`test_sigint_closes_lifetime_stack()` such that we test the SIGINT
being relayed to just the parent or the child.
Took me a while to figure out what the heck was going on but, turns out
`asyncio` changed their SIGINT handling in 3.11 as per:
https://docs.python.org/3/library/asyncio-runner.html#handling-keyboard-interruption
I'm not entirely sure if it's the 3.11 changes or possibly wtv further
updates were made in 3.12 but more or less due to the way
our current main task was written the `trio` guest-run was getting
abandoned on SIGINTs sent from the OS to the infected child proc..
Note that much of the bug and soln cases are layed out in very detailed
comment-notes both in the new test and `run_as_asyncio_guest()`, right
above the final "fix" lines.
Add new `test_infected_aio.test_sigint_closes_lifetime_stack()` test suite
which reliably triggers all abandonment issues with multiple cases
of different parent behaviour post-sending-SIGINT-to-child:
1. briefly sleep then raise a KBI in the parent which was originally
demonstrating the file leak not being cleaned up by `Actor.lifetime_stack.close()`
and simulates a ctl-c from the console (relayed in tandem by
the OS to the parent and child processes).
2. do `Context.wait_for_result()` on the child context which would
hang and timeout since the actor runtime would never complete and
thus never relay a `ContextCancelled`.
3. both with and without running a `asyncio` task in the `manage_file`
child actor; originally it seemed that with an aio task scheduled in
the child actor the guest-run abandonment always was the "loud" case
where there seemed to be some actor teardown but with tbs from
python failing to gracefully exit the `trio` runtime..
The (seemingly working) "fix" required 2 lines of code to be run inside
a `asyncio.CancelledError` handler around the call to `await trio_done_fut`:
- `Actor.cancel_soon()` which schedules the actor runtime to cancel on
the next `trio` runner cycle and results in a "self cancellation" of
the actor.
- "pumping the `asyncio` event loop" with a non-0 `.sleep(0.1)` XD
|_ seems that a "shielded" pump with some actual `delay: float >= 0`
did the trick to get `asyncio` to allow the `trio` runner/loop to
fully complete its guest-run without abandonment.
Other supporting changes:
- move `._exceptions.AsyncioCancelled`, our renamed
`asyncio.CancelledError` error-sub-type-wrapper, to `.to_asyncio` and make
it derive from `CancelledError` so as to be sure when raised by our
`asyncio` x-> `trio` exception relay machinery that `asyncio` is
getting the specific type it expects during cancellation.
- do "summary status" style logging in `run_as_asyncio_guest()` wherein
we compile the eventual `startup_msg: str` emitted just before waiting
on the `trio_done_fut`.
- shield-wait with `out: Outcome = await asyncio.shield(trio_done_fut)`
even though it seems to do nothing in the SIGINT handling case..(I
presume it might help avoid abandonment in a `asyncio.Task.cancel()`
case maybe?)
Since a local-actor-nursery-parented subactor might also use the root as
its registry, we need to avoid warning when short lived IPC `Channel`
connections establish and then disconnect (quickly, bc the apparently
the subactor isn't re-using an already cached parente-peer<->child conn
as you'd expect efficiency..) since such cases currently considered
normal operation of our super shoddy/naive "discovery sys" XD
As such, (un)guard the whole local-actor-nursery OR channel-draining
waiting blocks with the additional `or Actor._cancel_called` branch
since really we should also be waiting on the parent nurse to exit (at
least, for sure and always) when the local `Actor` indeed has been
"globally" cancelled-called. Further add separate timeout warnings for
channel-draining vs. local-actor-nursery-exit waiting since they are
technically orthogonal cases (at least, afaik).
Also,
- adjust the `Actor._stream_handler()` connection status log-emit to
`.runtime()`, especially to reduce noise around the aforementioned
ephemeral registree connection-requests.
- if we do wait on a local actor-nurse to exit, report its `._children`
table (which should help figure out going forward how useful the
warning is, if at all).
Name them `_mk_send_mte()`/`_mk_recv_mte()` and change the runtime to
call each appropriately depending on location/usage.
Also add some dynamic call-frame "unhide" blocks such that when we
expect raised MTE from the aboves calls but we get a different
unexpected error from the runtime, we ensure the call stack downward is
shown in tbs/pdb.
|_ ideally in the longer run we come up with a fancier dynamic sys for
this, prolly something in `.devx._frame_stack`?
Just pass `_bad_msg` such that it get's injected to `.msgdata` since
with a send-side `MsgTypeError` we don't have a remote `._ipc_msg:
Error` per say to include.
Namely passing the `.__pld_spec__` directly to the
`lock_stdio_for_peer()` decorator B)
Also, allows dropping `apply_debug_pldec()` (which was a todo) and
removing a `lock_stdio_for_peer()` indent level.
Instead of the WIP/prototyped `Portal.open_context()` offering
a `pld_spec` input arg, this changes to a proper decorator API for
specifying the "payload spec" on `@context` endpoints.
The impl change details actually cover 2-birds:
- monkey patch decorated functions with a new
`._tractor_context_meta: dict[str, Any]` and insert any provided input
`@context` kwargs: `_pld_spec`, `enc_hook`, `enc_hook`.
- use `inspect.get_annotations()` to scan for a `func` arg
type-annotated with `tractor.Context` and use the name of that arg as
the RPC task-side injected `Context`, thus injecting the needed arg
by type instead of by name (a longstanding TODO); raise a type-error
when not found.
- pull the `pld_spec` from the `._tractor_context_meta` attr both in the
`.open_context()` parent-side and child-side `._invoke()`-cation of
the RPC task and use the `msg._ops.maybe_limit_plds()` API to apply it
internally in the runtime for each case.
`RemoteActorError`s show this by default in their `.__repr__()`, and we
obvi capture and embed the src traceback in an `Error` msg prior to
transit, but for logging it's also handy to see the tb of any set
`Context._remote_error` on console especially when trying to decipher
remote error details at their origin actor. Also improve the log message
description using `ctx.repr_state` and show any `ctx.outcome`.
Longer run we don't want `tractor` app devs having to call
`msg._ops.limit_plds()` from every child endpoint.. so this starts
a list of decorator API ideas and obviously ties in with an ideal final
API design that will come with py3.13 and typed funcs. Obviously this
is directly fueled by,
- https://github.com/goodboy/tractor/issues/365
Other,
- type with direct `trio.lowlevel.Task` import.
- use `log.exception()` to show tbs for all error-terminations in
`.open_context()` (for now) and always explicitly mention the `.side`.
Hopefully would make grok-ing this fairly sophisticated sub-sys possible
for any up-and-coming `tractor` hacker
XD
A lot of internal API and re-org ideas I discovered/realized as part of
finishing the `__pld_spec__` and multi-threaded support. Particularly
better isolation between root-actor vs subactor task APIs and generally
less globally-state-ful stuff like `DebugStatus` and `Lock` method APIs
would likely make a lot of the hard to follow edge cases more clear?
Functionally working for multi-threaded (via cpython threads spawned
from `to_trio.to_thread.run_sync()`) alongside subactors, tested (for
now) only with threads started inside the root actor (which seemed to
have the most issues in terms of the impl and special cases..) using the
new `tractor.pause_from_sync()` API!
Main implementation changes to `.pause_from_sync()`
------ - ------
- from the root actor, we need to ensure bg thread case is handled
*specially* since no IPC is used to request the TTY stdio mutex and
`Lock` (API) usage is conducted entirely from a local task or thread;
dedicated `Lock` usage for the root-actor already is branched inside
`._pause()` and needs similar handling from a root bg-thread:
|_for the special case of a root bg thread we need to
`trio`-main-thread schedule a bg task inside a new
`_pause_from_bg_root_thread()`. The new task needs to implement most
of what was is handled inside `._pause()` manually, mostly because in
this root-actor-bg-thread case we have 2 constraints:
1. to enter `PdbREPL.interaction()` **from the bg thread** directly,
2. the task that `Lock._debug_lock.acquire()`s has to be the same
that calls `.release() (a `trio.FIFOLock` constraint)
|_impl deats of this `_pause_from_bg_root_thread()` include:
- (for now) calling `._pause()` to acquire the `Lock._debug_lock`.
- setting its own `DebugStatus.repl_release`.
- calling `.DebugStatus.shield_sigint()` to ensure the root's
main thread uses the right handler when the bg one is REPL-ing.
- wait manually on the `.repl_release()` to be set by the thread's
dedicated `PdbREPL` exit.
- manually calling `Lock.release()` from the **same task** that
acquired it.
- expect calls to `._pause()` to deliver a `tuple[Task, PdbREPL]` such
that we always get the handle both to any newly created REPl instance
and the (maybe) the scheduled bg task within which is runs.
- add a single `message: str` style to `log.devx()` based on branching
style for logging.
- ensure both `DebugStatus.repl` and `.repl_task` are set **just
before** calling `._set_trace()` to ensure the correct `Task|Thread`
is set when the REPL is finally entered from sync code.
- add a wrapping caller `_sync_pause_from_builtin()` which passes in the
new `called_from_builtin=True` to indicate `breakpoint()` caller
usage, obvi pass in `api_frame`.
Changes to `._pause()` in support of ^
------ - ------
- `TaskStatus.started()` and return the `tuple[Task, PdbREPL]` to
callers / starters.
- only call `DebugStatus.shield_sigint()` when no `repl` passed bc some
callers (like bg threads) may need to apply it at some specific point
themselves.
- tweak some asserts for the `debug_func == None` / non-`trio`-thread
case.
- add a mod-level `_repl_fail_msg: str` to be used when there's an
internal `._pause()` failure for testing, easier to pexpect match.
- more comprehensive logging for the root-actor branched case to
(attempt to) indicate any of the 3 cases:
- remote ctx from subactor has the `Lock`,
- already existing root task or thread has it or,
- some kinda stale `.locked()` situation where the root has the lock
but we don't know why.
- for root usage, revert to always `await Lock._debug_lock.acquire()`-ing
despite `called_from_sync` since `.pause_from_sync()` was reworked to
instead handle the special bg thread case in the new
`_pause_from_bg_root_thread()` task.
- always do `return _enter_repl_sync(debug_func)`.
- try to report any `repl_task: Task|Thread` set by the caller
(particularly for the bg thread cases) as being the thread or task
`._pause()` was called "on behalf of"
Changes to `DebugStatus`/`Lock` in support of ^
------ - ------
- only call `Lock.release()` from `DebugStatus.set_[quit/continue]()`
when called from the main `trio` thread and always call
`DebugStatus.release()` **after** to ensure `.repl_released()` is set
**after** `._debug_lock.release()`.
- only call `.repl_release.set()` from `trio` thread otherwise use
`.from_thread.run()`.
- much more refinements in `Lock.release()` for threading cases:
- return `bool` to indicate whether lock was released by caller.
- mask (in prep to drop) `_pause()` usage of
`Lock.release.force=True)` since forcing a release can't ever avoid
the RTE from `trio`.. same task **must** acquire/release.
- don't allow usage from non-`trio`-main-threads, ever; there's no
point since the same-task-needs-to-manage-`FIFOLock` constraint.
- much more detailed logging using `message`-building-style for all
caller (edge) cases.
|_ use a `we_released: bool` to determine failed-to-release edge
cases which can happen if called from bg threads, ensure we
`log.exception()` on any incorrect usage resulting in release
failure.
|_ complain loudly if the release fails and some other task/thread
still holds the lock.
|_ be explicit about "who" (which task or thread) the release is "on
behalf of" by reading `DebugStatus.repl_task` since the caller
isn't the REPL operator in many sync cases.
- more or less drop `force` support, as mentioned above.
- ensure we unset `._owned_by_root` if the caller is a root task.
Other misc
------ - ------
- rename `lock_tty_for_child()` -> `lock_stdio_for_peer()`.
- rejig `Lock.repr()` to show lock and event stats.
- stage `Lock.stats` and `.owner` methods in prep for doing a singleton
instance and `@property`s.
Originally discovered as while using `tractor.pause_from_sync()`
from the `i3ipc` client running in a bg-thread that uses `asyncio`
inside `modden`.
Turns out we definitely aren't correctly handling `.pause_from_sync()`
from the root actor when called from a `trio.to_thread.run_sync()`
bg thread:
- root-actor bg threads which can't `Lock._debug_lock.acquire()` since
they aren't in `trio.Task`s.
- even if scheduled via `.to_thread.run_sync(_debug._pause)` the
acquirer won't be the task/thread which calls `Lock.release()` from
`PdbREPL` hooks; this results in a RTE raised by `trio`..
- multiple threads will step on each other's stdio since cpython's GIL
seems to ctx switch threads on every input from the user to the REPL
loop..
Reproduce via reworking our example and test so that they catch and fail
for all edge cases:
- rework the `/examples/debugging/sync_bp.py` example to demonstrate the
above issues, namely the stdio clobbering in the REPL when multiple
threads and/or a subactor try to debug simultaneously.
|_ run one thread using a task nursery to ensure it runs conc with the
nursery's parent task.
|_ ensure the bg threads run conc a subactor usage of
`.pause_from_sync()`.
|_ gravely detail all the special cases inside a TODO comment.
|_ add some control flags to `sync_pause()` helper and don't use
`breakpoint()` by default.
- extend and adjust `test_debugger.test_pause_from_sync` to match (and
thus currently fail) by ensuring exclusive `PdbREPL` attachment when
the 2 bg root-actor threads are concurrently interacting alongside the
subactor:
|_ should only see one of the `_pause_msg` logs at a time for either
one of the threads or the subactor.
|_ ensure each attaches (in no particular order) before expecting the
script to exit.
Impl adjustments to `.devx._debug`:
- drop `Lock.repl`, no longer used.
- add `Lock._owned_by_root: bool` for the `.ctx_in_debug == None`
root-actor-task active case.
- always `log.exception()` for any `._debug_lock.release()` ownership
RTE emitted by `trio`, like we used to..
- add special `Lock.release()` log message for the stale lock but
`._owned_by_root == True` case; oh yeah and actually
`log.devx(message)`..
- rename `Lock.acquire()` -> `.acquire_for_ctx()` since it's only ever
used from subactor IPC usage; well that and for local root-task
usage we should prolly add a `.acquire_from_root_task()`?
- buncha `._pause()` impl improvements:
|_ type `._pause()`'s `debug_func` as a `partial` as well.
|_ offer `called_from_sync: bool` and `called_from_bg_thread: bool`
for the special case handling when called from `.pause_from_sync()`
|_ only set `DebugStatus.repl/repl_task` when `debug_func != None`
(OW ensure the `.repl_task` is not the current one).
|_ handle error logging even when `debug_func is None`..
|_ lotsa detailed commentary around root-actor-bg-thread special cases.
- when `._set_trace(hide_tb=False)` do `pdbp.set_trace(frame=currentframe())`
so the `._debug` internal frames are always included.
- by default always hide tracebacks for `.pause[_from_sync]()` internals.
- improve `.pause_from_sync()` to avoid root-bg-thread crashes:
|_ pass new `called_from_xxx_` flags and ensure `DebugStatus.repl_task`
is actually set to the `threading.current_thread()` when needed.
|_ manually call `Lock._debug_lock.acquire_nowait()` for the non-bg
thread case.
|_ TODO: still need to implement the bg-thread case using a bg
`trio.Task`-in-thread with an `trio.Event` set by thread REPL exit.
Exactly like how it's organized for `Portal.open_context()`, put the
main streaming API `@acm` with the `MsgStream` code and bind the method
to the new module func.
Other,
- rename `Context.result()` -> `.wait_for_result()` to better match the
blocking semantics and rebind `.result()` as deprecated.
- add doc-str for `Context.maybe_raise()`.
It ended up getting necessarily implemented as the `PldRx` though at
a different layer and won't be needed as part of `MsgCodec` most likely,
though this original idea did provide the source of inspiration for how
things work now!
Also Move the commented TODO proto for a codec hook factory from
`.types` to `._codec` where it prolly better fits and update some msg
related todo/questions.
It's been a long time prepped and now finally implemented!
Offer a `shield: bool` argument from our async `._debug` APIs:
- `await tractor.pause(shield=True)`,
- `await tractor.post_mortem(shield=True)`
^-These-^ can now be used inside cancelled `trio.CancelScope`s,
something very handy when introspecting complex (distributed) system
tear/shut-downs particularly under remote error or (inter-peer)
cancellation conditions B)
Thanks to previous prepping in a prior attempt and various patches from
the rigorous rework of `.devx._debug` internals around typed msg specs,
there ain't much that was needed!
Impl deats
- obvi passthrough `shield` from the public API endpoints (was already
done from a prior attempt).
- put ad-hoc internal `with trio.CancelScope(shield=shield):` around all
checkpoints inside `._pause()` for both the root-process and subactor
case branches.
Add a fairly rigorous example, `examples/debugging/shielded_pause.py`
with a wrapping `pexpect` test, `test_debugger.test_shield_pause()` and
ensure it covers as many cases as i can think of offhand:
- multiple `.pause()` entries in a loop despite parent scope
cancellation in a subactor RPC task which itself spawns a sub-task.
- a `trio.Nursery.parent_task` which raises, is handled and
tries to enter and unshielded `.post_mortem()`, which of course
internally raises `Cancelled` in a `._pause()` checkpoint, so we catch
the `Cancelled` again and then debug the debugger's internal
cancellation with specific checks for the particular raising
checkpoint-LOC.
- do ^- the latter -^ for both subactor and root cases to ensure we
can debug `._pause()` itself when it tries to REPL engage from
a cancelled task scope Bo
Keep the old alias, but i think it's better form to use longer names for
internal public APIs and this name better reflects the functionality:
decoding and returning a `PayloadMsg.pld` field.
Such that we're boxing the interchanged lib's specific error
`msgspec.ValidationError` in this case) type much like how
a `ContextCancelled[trio.Cancelled]` is composed; allows for seemless
multi-backend-codec support later as well B)
Pass `ctx.maybe_raise(from_src_exc=src_err)` where needed in a couple
spots; as `None` in the send-side `Started` MTE case to avoid showing
the `._scope1.cancel_called` result in the traceback from the
`.open_context()` child-sync phase.
That is as a control to `Context._maybe_raise_remote_err()` such that
if set to anything other then the default (`False` value), we do
`raise remote_error from from_src_exc` such that caller can choose to
suppress or override the `.__cause__` tb.
Also tidy up and old masked TODO regarding calling `.maybe_raise()`
after the caller exits from the `yield` in `.open_context()`..
Send-side `MsgTypeError`s actually shouldn't have any "boxed" traceback
per say since they're raised in the transmitting actor's local task env
and we (normally) don't want the ascii decoration added around the
error's `._message: str`, that is not until the exc is `pack_error()`-ed
before transit. As such, the presentation of an embedded traceback (and
its ascii box) gets bypassed when only a `._message: str` is set (as we
now do for pld-spec failures in `_mk_msg_type_err()`).
Further this tweaks the `.pformat()` output to include the `._message`
part to look like `<RemoteActorError( <._message> ) ..` instead of
jamming it implicitly to the end of the embedded `.tb_str` (as was done
implicitly by `unpack_error()`) and also adds better handling for the
`with_type_header == False` case including forcing that case when we
detect that the currently handled exc is the RAE in `.pformat()`.
Toss in a lengthier doc-str explaining it all.
Surrounding/supporting changes,
- better `unpack_error()` message which just briefly reports the remote
task's error type.
- add public `.message: str` prop.
- always set a `._extra_msgdata: dict` since some MTE props rely on it.
- handle `.boxed_type == None` for `.boxed_type_str`.
- maybe pack any detected input or `exc.message` in `pack_error()`.
- comment cruft cleanup in `_mk_msg_type_err()`.
Allows passing a custom error msg other then the traceback-str over the
wire. Make `.tb_str` optional (in the blank `''` sense) since it's
treated that way thus far in `._exceptions.pack_error()`.
More specifically, if `.open_context()` is cancelled when awaiting the
first `Context.started()` during the child task sync phase, check to see
if it was due to `._scope.cancel_called` and raise any remote error via
`.maybe_raise()` instead the `trio.Cancelled` like in every other
remote-error handling case. Ensure we set `._scope[_nursery]` only after
the `Started` has arrived and audited.
Since in the case of the `Actor._cancel_task()` related runtime eps we
actually don't EVER register them in `Actor._rpc_tasks`.. logging about
them is just needless noise, though maybe we should track them in a diff
table; something like a `._runtime_rpc_tasks`?
Drop the cancel-request-for-stale-RPC-task (`KeyError` case in
`Actor._cancel_task()`) log-emit level in to `.runtime()`; it's
generally not useful info other then for granular race condition eval
when hacking the runtime.
So when `is_started_send_side is True` we raise the newly created
`MsgTypeError` (MTE) directly instead of doing all the `Error`-msg pack
and unpack to raise stuff via `_raise_from_unexpected_msg()` since the
raise should happen send side anyway and so doesn't emulate any remote
fault like in a bad `Return` or `Started` without send-side pld-spec
validation.
Oh, and proxy-through the `hide_tb: bool` input from `.drain_to_final_msg()`
to `.recv_msg_w_pld()`.
By calling `Context._maybe_cancel_and_set_remote_error(exc)` on any
unpacked `Error` msg; provides for `Context.maybe_error` consistency to
match all other error delivery cases.
Filling out the helper `validate_payload_msg()` staged in a prior commit
and adjusting all imports to match.
Also add a `raise_mte: bool` flag for potential usage where the caller
wants to handle the MTE instance themselves.
The `TypeAlias` for the msg type-group is now `MsgType` and any user
touching shuttle messages can now be typed as `PayloadMsg`.
Relatedly, add MTE specific `Error._bad_msg[_as_dict]` fields which are
handy for introspection of remote decode failures.
Such that if caught by user code and/or the runtime we can introspect
the original msg which caused the type error. Previously this was kinda
half-baked with a `.msg_dict` which was delivered from an `Any`-decode
of the shuttle msg in `_mk_msg_type_err()` but now this more explicitly
refines the API and supports both `PayloadMsg`-instance or the msg-dict
style injection:
- allow passing either of `bad_msg: PayloadMsg|None` or
`bad_msg_as_dict: dict|None` to `MsgTypeError.from_decode()`.
- expose public props for both ^ whilst dropping prior `.msgdict`.
- rework `.from_decode()` to explicitly accept `**extra_msgdata: dict`
|_ only overriding it from any `bad_msg_as_dict` if the keys are found in
`_ipcmsg_keys`, **except** for `_bad_msg` when `bad_msg` is passed.
|_ drop `.ipc_msg` passthrough.
|_ drop `msgdict` input.
- adjust `.cid` to only pull from the `.bad_msg` if set.
Related fixes/adjustments:
- `pack_from_raise()` should pull `boxed_type_str` from
`boxed_type.__name__`, not the `type()` of it.. also add a
`hide_tb: bool` flag.
- don't include `_msg_dict` and `_bad_msg` in the `_body_fields` set.
- allow more granular boxed traceback-str controls:
|_ allow passing a `tb_str: str` explicitly in which case we use it
verbatim and presume caller knows what they're doing.
|_ when not provided, use the more explicit
`traceback.format_exception(exc)` since the error instance is
a required input (we still fail back to the old `.format_exc()` call
if for some reason the caller passes `None`; but that should be
a bug right?).
|_ if a `tb: TracebackType` and a `tb_str` is passed, concat them.
- in `RemoteActorError.pformat()` don't indent the `._message` part used
for the `body` when `with_type_header == False`.
- update `_mk_msg_type_err()` to use `bad_msg`/`bad_msg_as_dict`
appropriately and drop passing `ipc_msg`.
In the sense that we handle it as a special case that exposed
through to `RxPld.dec_msg()` with a new `is_started_send_side: bool`.
(Non-ideal) `Context.started()` impl deats:
- only do send-side pld-spec validation when a new `validate_pld_spec`
is set (by default it's not).
- call `self.pld_rx.dec_msg(is_started_send_side=True)` to validate the
payload field from the just codec-ed `Started` msg's `msg_bytes` by
passing the `roundtripped` msg (with it's `.pld: Raw`) directly.
- add a `hide_tb: bool` param and proxy it to the `.dec_msg()` call.
(Non-ideal) `PldRx.dec_msg()` impl deats:
- for now we're packing the MTE inside an `Error` via a manual call to
`pack_error()` and then setting that as the `msg` passed to
`_raise_from_unexpected_msg()` (though really we should just raise
inline?).
- manually set the `MsgTypeError._ipc_msg` to the above..
Other,
- more comprehensive `Context` type doc string.
- various `hide_tb: bool` kwarg additions through `._ops.PldRx` meths.
- proto a `.msg._ops.validate_payload_msg()` helper planned to get the
logic from this version of `.started()`'s send-side validation so as
to be useful more generally elsewhere.. (like for raising back
`Return` values on the child side?).
Warning: this commit may have been made out of order from required
changes to `._exceptions` which will come in a follow up!
Related to the prior patch, re the new `with_type_header: bool`:
- in the `with_type_header == True` use case make sure we keep the first
`._message: str` line non-indented since it'll show just after the
header-line's type path with ':'.
- when `False` drop the `)>` `repr()`-instance style as well so that we
just get the ascii boxed traceback as though it's the error
message-`str` not the `repr()` of the error obj.
Other,
- hide `pack_from_raise()` call frame since it'll show in debug mode
crash handling..
- mk `MsgTypeError.from_decode()` explicitly accept and proxy an
optional `ipc_msg` and change `msgdict` to also be optional, only
reading out the `**extra_msgdata` when provided.
- expose a `_mk_msg_type_err(src_err_msg: Error|None = None,)` for
callers who which to inject a `._ipc_msg: Msgtype` to the MTE.
|_ add a note how we can't use it due to a causality-dilemma when pld
validating `Started` on the send side..
And IFF the `await wait_func(proc)` is cancelled such that we avoid
clobbering some subactor that might be REPL-ing even though its parent
actor is in the midst of (gracefully) cancelling it.
From both `open_root_actor()` and `._entry._trio_main()`.
Other `breakpoint()`-from-sync-func fixes:
- properly disable the default hook using `"0"` XD
- offer a `hide_tb: bool` from `open_root_actor()`.
- disable hiding the `._trio_main()` frame, bc pretty sure it doesn't
help anyone (either way) when REPL-ing/tb-ing from a subactor..?
Call it `hide_runtime_frames()` and stick all the lines from the top of
the `._debug` mod in there along with a little `log.devx()` emission on
what gets hidden by default ;)
Other,
- fix ref-error where internal-error handler might trigger despite the
debug `req_ctx` not yet having init-ed, such that we don't try to
cancel or log about it when it never was fully created/initialize..
- fix assignment typo iniside `_set_trace()` for `task`.. lel
Such that when displaying with `.__str__()` we do not show the type
header (style) since normally python's raising machinery already prints
the type path like `'tractor._exceptions.RemoteActorError:'`, so doing
it 2x is a bit ugly ;p
In support,
- include `.relay_uid` in `RemoteActorError.extra_body_fields`.
- offer a `with_type_header: bool` to `.pformat()` and only put the
opening type path and closing `')>'` tail line when `True`.
- add `.is_inception() -> bool:` for an easy way to determine if the
error is multi-hop relayed.
- only repr the `'|_relay_uid=<uid>'` field when an error is an inception.
- tweak the invalid-payload case in `_mk_msg_type_err()` to explicitly
state in the `message` how the `any_pld` value does not match the `MsgDec.pld_spec`
by decoding the invalid `.pld` with an any-dec.
- allow `_mk_msg_type_err(**mte_kwargs)` passthrough.
- pass `boxed_type=cls` inside `MsgTypeError.from_decode()`.
More or less by pedantically separating and managing root and subactor
request syncing events to always be managed by the locking IPC context
task-funcs:
- for the root's "child"-side, `lock_tty_for_child()` directly creates
and sets a new `Lock.req_handler_finished` inside a `finally:`
- for the sub's "parent"-side, `request_root_stdio_lock()` does the same
with a new `DebugStatus.req_finished` event and separates it from
the `.repl_release` event (which indicates a "c" or "q" from user and
thus exit of the REPL session) as well as sets a new `.req_task:
trio.Task` to explicitly distinguish from the app-user-task that
enters the REPL vs. the paired bg task used to request the global
root's stdio mutex alongside it.
- apply the `__pld_spec__` on "child"-side of the ctx using the new
`Portal.open_context(pld_spec)` parameter support; drops use of any
`ContextVar` malarky used prior for `PldRx` mgmt.
- removing `Lock.no_remote_has_tty` since it was a nebulous name and
from the prior "everything is in a `Lock`" design..
------ - ------
More rigorous impl to handle various edge cases in `._pause()`:
- rejig `_enter_repl_sync()` to wrap the `debug_func == None` case
inside maybe-internal-error handler blocks.
- better logic for recurrent vs. multi-task contention for REPL entry in
subactors, by guarding using `DebugStatus.req_task` and by now waiting
on the new `DebugStatus.req_finished` for the multi-task contention
case.
- even better internal error handling and reporting for when this code
is hacked on and possibly broken ;p
------ - ------
Updates to `.pause_from_sync()` support:
- add optional `actor`, `task` kwargs to `_set_trace()` to allow
compat with the new explicit `debug_func` calling in `._pause()` and
pass a `threading.Thread` for `task` in the `.to_thread()` usage case.
- add an `except` block that tries to show the frame on any internal
error.
------ - ------
Relatedly includes a buncha cleanups/simplifications somewhat in
prep for some coming refinements (around `DebugStatus`):
- use all the new attrs mentioned above as needed in the SIGINT shielder.
- wait on `Lock.req_handler_finished` in `maybe_wait_for_debugger()`.
- dropping a ton of masked legacy code left in during the recent reworks.
- better comments, like on the use of `Context._scope` for shielding on
the "child"-side to avoid the need to manage yet another cs.
- add/change-to lotsa `log.devx()` level emissions for those infos which
are handy while hacking on the debugger but not ideal/necessary to be
user visible.
- obvi add lotsa follow up todo notes!
Much like other recent changes attempt to detect runtime-bug-causing
crashes and only show the runtime-endpoint frame when present.
Adds a `ActorNursery._scope_error: BaseException|None` attr to aid with
detection. Also toss in some todo notes for removing and replacing the
`.run_in_actor()` method API.
Just inside `._invoke()` after the `ctx: Context` is retrieved.
Also try our best to *not hide* internal frames when a non-user-code
crash happens, normally either due to a runtime RPC EP bug or
a transport failure.
Kinda like a "runtime"-y level for `.pdb()` (which is more or less like
an `.info()` for our debugger subsys) which can be used to report
internals info for those hacking on `.devx` tools.
Also, inject only the *last* 6 digits of the `id(Task)` in
`pformat_task_uid()` output by default.
Tyler Goodlet