New pytest module `tests/spawn/test_subint_forkserver.py`
drives the forkserver primitives from inside a real
`trio.run()` in the parent — the runtime shape tractor will
actually use when we wire up a `subint_forkserver` spawn
backend proper. Complements the standalone no-trio-in-parent
`ai/conc-anal/subint_fork_from_main_thread_smoketest.py`.
Deats,
- new test pkg `tests/spawn/` (+ empty `__init__.py`)
- two tests, both `@pytest.mark.timeout(30, method='thread')`
for the GIL-hostage safety reason doc'd in
`ai/conc-anal/subint_sigint_starvation_issue.md`:
- `test_fork_from_worker_thread_via_trio` — parent-side
plumbing baseline. `trio.run()` off-loads forkserver
prims via `trio.to_thread.run_sync()` + asserts the
child reaps cleanly
- `test_fork_and_run_trio_in_child` — end-to-end: forked
child calls `run_subint_in_worker_thread()` with a
bootstrap str that does `trio.run()` in a fresh subint
- both tests wrap the inner `trio.run()` in a
`dump_on_hang()` for post-mortem if the outer
`pytest-timeout` fires
- intentionally NOT using `--spawn-backend` — the tests
drive the primitives directly rather than going through
tractor's spawn-method registry (which the forkserver
isn't plugged into yet)
Also, rename `run_trio_in_subint()` →
`run_subint_in_worker_thread()` for naming consistency with
the sibling `fork_from_worker_thread()`. The action is really
"host a subint on a worker thread", not specifically "run
trio" — trio just happens to be the typical payload.
Propagate the rename to the smoketest.
Further, add a "TODO — cleanup gated on msgspec PEP 684
support" section to the `_subint_forkserver` module
docstring: flags the dedicated-`threading.Thread` design as
potentially-revisable once isolated-mode subints are viable
in tractor. Cross-refs `msgspec#563` + `tractor#379` and
points at an audit-plan conc-anal doc we'll add next.
(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit 25e400d526)
The smoketest (prior commit) empirically validated the
"fork-from-main-interp-worker-thread" arch on py3.14. Promote
the validated primitives out of the `ai/conc-anal/` smoketest
into `tractor.spawn._subint_forkserver` so they can eventually
be wired into a real "subint forkserver" spawn backend.
Deats,
- new module `tractor/spawn/_subint_forkserver.py` (337 LOC):
- `fork_from_worker_thread(child_target, thread_name)` —
spawn a main-interp `threading.Thread`, call `os.fork()`
from it, shuttle the child pid back to main via a pipe
- `run_trio_in_subint(bootstrap, ...)` — post-fork helper:
create a fresh subint + drive `_interpreters.exec()` on
a dedicated worker thread running the `bootstrap` str
(typically imports `trio`, defines an async entry, calls
`trio.run()`)
- `wait_child(pid, expect_exit_ok)` — `os.waitpid()` +
pass/fail classification reusable from harness AND the
eventual real spawn path
- feature-gated py3.14+ via the public
`concurrent.interpreters` presence check; matches the gate
in `tractor.spawn._subint`
- module docstring doc's the CPython-block context
(cross-refs `_subint_fork` stub + the two `conc-anal/`
docs) and status: EXPERIMENTAL, not yet registered in
`_spawn._methods`
Also, refactor the smoketest
`ai/conc-anal/subint_fork_from_main_thread_smoketest.py` to
import the primitives from the new module rather than inline
its own copies. Keeps the smoketest and the tractor-side
impl in sync as the forkserver design evolves; the smoketest
remains a zero-`tractor`-runtime CPython-level check
(imports ONLY the three primitives, no runtime bring-up).
Status: next step is to drive these from a parent-side
`trio.run()` and hook the returned child pid into the normal
actor-nursery/IPC flow — then register `subint_forkserver`
as a `SpawnMethodKey` in `_spawn.py`.
(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit 82332fbceb)
Empirical finding: the WIP `subint_fork_proc` scaffold
landed in `cf0e3e6f` does *not* work on current CPython.
The `fork()` syscall succeeds in the parent, but the
CHILD aborts immediately during
`PyOS_AfterFork_Child()` →
`_PyInterpreterState_DeleteExceptMain()`, which gates
on the current tstate belonging to the main interp —
the child dies with `Fatal Python error: not main
interpreter`.
CPython devs acknowledge the fragility with an in-source
comment (`// Ideally we could guarantee tstate is running
main.`) but expose no user-facing hook to satisfy the
precondition — so the strategy is structurally dead until
upstream changes.
Rather than delete the scaffold, reshape it into a
documented dead-end so the next person with this idea
lands on the reason rather than rediscovering the same
CPython-level refusal.
Deats,
- Move `subint_fork_proc` out of `tractor.spawn._subint`
into a new `tractor.spawn._subint_fork` dedicated
module (153 LOC). Module + fn docstrings now describe
the blockage directly; the fn body is trimmed to a
`NotImplementedError` pointing at the analysis doc —
no more dead-code `bootstrap` sketch bloating
`_subint.py`.
- `_spawn.py`: keep `'subint_fork'` in `SpawnMethodKey`
+ the `_methods` dispatch so
`--spawn-backend=subint_fork` routes to a clean
`NotImplementedError` rather than "invalid backend";
comment calls out the blockage. Collapse the duplicate
py3.14 feature-gate in `try_set_start_method()` into a
combined `case 'subint' | 'subint_fork':` arm.
- New 337-line analysis:
`ai/conc-anal/subint_fork_blocked_by_cpython_post_fork_issue.md`.
Annotated walkthrough from the user-visible fatal
error down to the specific `Modules/posixmodule.c` +
`Python/pystate.c` source lines enforcing the refusal,
plus an upstream-report draft.
(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit 0f48ed2eb9)
Experimental third spawn backend: use a fresh
sub-interpreter purely as a trio-free launchpad from
which to `os.fork()` + exec back into
`python -m tractor._child`. Per issue #379's
"fork()-workaround/hacks" thread.
Intent is to sidestep both,
- the trio+fork hazards hitting `trio_proc` (python- trio/trio#1614 et
al.), since the forking interp is guaranteed trio-free.
- the shared-GIL abandoned-thread hazards hitting `subint_proc`
(`ai/conc-anal/subint_sigint_starvation_issue.md`), since we don't
*stay* in the subint — it only lives long enough to call `os.fork()`
Downstream of the fork+exec, all the existing `trio_proc` plumbing is
reused verbatim: `ipc_server.wait_for_peer()`, `SpawnSpec`, `Portal`
yield, soft-kill.
Status: NOT wired up beyond scaffolding. The fn raises
`NotImplementedError` immediately; the `bootstrap` fork/exec string
builder and the `# TODO: orchestrate driver thread` block are kept
in-tree as deliberate dead code so the next iteration starts from
a concrete shape rather than a blank page.
Docstring calls out three open questions that need
empirical validation before wiring this up:
1. Does CPython permit `os.fork()` from a non-main
legacy subint?
2. Can the child stay fork-without-exec and
`trio.run()` directly from within the launchpad
subint?
3. How do `signal.set_wakeup_fd()` handlers and other
process-global state interact when the forking
thread is inside a subint?
(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit eee79a0357)
The private `_interpreters` C module ships since 3.13, but that vintage
wedges under our `threading.Thread` + multi-trio usage pattern
—> `_interpreters.exec()` silently never makes progress. 3.14 fixes it.
So gate on the presence of the public `concurrent.interpreters` wrapper
(3.14+ only) even tho we still call into the private module at runtime.
Deats,
- `try_set_start_method('subint')` error msg + `_subint` module
docstring/comments rewritten to document the 3.14 floor and why 3.13
can't work.
- `_subint._has_subints` gate now imports `concurrent.interpreters` (not
`_interpreters`) as the version sentinel.
Also, reshuffle `pyproject.toml` deps into
per-python-version `[tool.uv.dependency-groups]`:
- `subints` group: `msgspec>=0.21.0`, py>=3.14
- `eventfd` group: `cffi>=1.17.1`, py>=3.13,<3.14
- `sync_pause` group: `greenback`, py>=3.13,<3.14
(was in `devx`; moved out bc no 3.14 yet)
Bump top-level `msgspec>=0.20.0` too.
(this commit msg was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit 34d9d482e4)
(MTF-only portion: kept tractor/spawn/_spawn.py tractor/spawn/_subint.py)
Unbounded `trio.CancelScope(shield=True)` at the
soft-kill and thread-join sites can wedge the parent
trio loop indefinitely when a stuck subint ignores
portal-cancel (e.g. bc the IPC channel is already
broken).
Deats,
- add `_HARD_KILL_TIMEOUT` (3s) module-level const
- wrap both shield sites with
`trio.move_on_after()` so we abandon a stuck
subint after the deadline
- flip driver thread to `daemon=True` so proc-exit
also isn't blocked by a wedged subint
- pass `abandon_on_cancel=True` to
`trio.to_thread.run_sync(driver_thread.join)`
— load-bearing for `move_on_after` to actually
fire
- log warnings when either timeout triggers
- improve `InterpreterError` log msg to explain
the abandoned-thread scenario
(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit 99541feec7)
`trio.to_thread.run_sync(_interpreters.exec, ...)` runs `exec()` on
a cached worker thread — and when that thread is returned to the
cache after the subint's `trio.run()` exits, CPython still keeps
the subint's tstate attached to the (now idle) worker. Result: the
teardown `_interpreters.destroy(interp_id)` in the `finally` block
can block the parent's trio loop indefinitely, waiting for a tstate
release that only happens when the worker either picks up a new job
or exits.
Manifested as intermittent mid-suite hangs under
`--spawn-backend=subint` — caught by a
`faulthandler.dump_traceback_later()` showing the main thread stuck
in `_interpreters.destroy()` at `_subint.py:293` with only an idle
trio-cache worker as the other live thread.
Deats,
- drive the subint on a plain `threading.Thread` (not
`trio.to_thread`) so the OS thread truly exits after
`_interpreters.exec()` returns, releasing tstate and unblocking
destroy
- signal `subint_exited.set()` back to the parent trio loop from
the driver thread via `trio.from_thread.run_sync(...,
trio_token=...)` — capture the token at `subint_proc` entry
- swallow `trio.RunFinishedError` in that signal path for the case
where parent trio has already exited (proc teardown)
- in the teardown `finally`, off-load the sync
`driver_thread.join()` to `trio.to_thread.run_sync` (cache thread
w/ no subint tstate → safe) so we actually wait for the driver to
exit before `_interpreters.destroy()`
(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit 31cbd11a5b)
Expand the comment block above the `_interpreters`
import explaining *why* we use the private C mod
over `concurrent.interpreters`: the public API only
exposes PEP 734's `'isolated'` config which breaks
`msgspec` (missing PEP 684 slot). Add reference
links to PEP 734, PEP 684, cpython sources, and
the msgspec upstream tracker (jcrist/msgspec#563).
Also,
- update error msgs in both `_spawn.py` and
`_subint.py` to say "3.13+" (matching the actual
`_interpreters` availability) instead of "3.14+".
- tweak the mod docstring to reflect py3.13+
availability via the private C module.
Review: PR #444 (copilot-pull-request-reviewer)
https://github.com/goodboy/tractor/pull/444
(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit 8a8d01e076)
Replace the B.1 scaffold stub w/ a working spawn
flow driving PEP 734 sub-interpreters on dedicated
OS threads.
Deats,
- use private `_interpreters` C mod (not the public
`concurrent.interpreters` API) to get `'legacy'`
subint config — avoids PEP 684 C-ext compat
issues w/ `msgspec` and other deps missing the
`Py_mod_multiple_interpreters` slot
- bootstrap subint via code-string calling new
`_actor_child_main()` from `_child.py` (shared
entry for both CLI and subint backends)
- drive subint lifetime on an OS thread using
`trio.to_thread.run_sync(_interpreters.exec, ..)`
- full supervision lifecycle mirrors `trio_proc`:
`ipc_server.wait_for_peer()` → send `SpawnSpec`
→ yield `Portal` via `task_status.started()`
- graceful shutdown awaits the subint's inner
`trio.run()` completing; cancel path sends
`portal.cancel_actor()` then waits for thread
join before `_interpreters.destroy()`
Also,
- extract `_actor_child_main()` from `_child.py`
`__main__` block as callable entry shape bc the
subint needs it for code-string bootstrap
- add `"subint"` to the `_runtime.py` spawn-method
check so child accepts `SpawnSpec` over IPC
Prompt-IO: ai/prompt-io/claude/20260417T124437Z_5cd6df5_prompt_io.md
(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit b8f243e98d)
(MTF-only portion: kept ai/prompt-io/claude/20260417T124437Z_5cd6df5_prompt_io.md ai/prompt-io/claude/20260417T124437Z_5cd6df5_prompt_io.raw.md tractor/spawn/_subint.py)
Land the scaffolding for a future sub-interpreter (PEP 734
`concurrent.interpreters`) actor spawn backend per issue #379. The
spawn flow itself is not yet implemented; `subint_proc()` raises a
placeholder `NotImplementedError` pointing at the tracking issue —
this commit only wires up the registry, the py-version gate, and
the harness.
Deats,
- bump `pyproject.toml` `requires-python` to `>=3.12, <3.15` and
list the `3.14` classifier — the new stdlib
`concurrent.interpreters` module only ships on 3.14
- extend `SpawnMethodKey = Literal[..., 'subint']`
- `try_set_start_method('subint')` grows a new `match` arm that
feature-detects the stdlib module and raises `RuntimeError` with
a clear banner on py<3.14
- `_methods` registers the new `subint_proc()` via the same
bottom-of-module late-import pattern used for `._trio` / `._mp`
Also,
- new `tractor/spawn/_subint.py` — top-level `try: from concurrent
import interpreters` guards `_has_subints: bool`; `subint_proc()`
signature mirrors `trio_proc`/`mp_proc` so the Phase B.2 impl can
drop in without touching the registry
- re-add `import sys` to `_spawn.py` (needed for the py-version msg
in the gate-error)
- `_testing.pytest.pytest_configure` wraps `try_set_start_method()`
in a `pytest.UsageError` handler so `--spawn-backend=subint` on
py<3.14 prints a clean banner instead of a traceback
(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit d318f1f8f4)
(MTF-only portion: kept tractor/spawn/_spawn.py tractor/spawn/_subint.py)
A `trio.Nursery.start()`-style wrapper around
`trio.run_process()` that surfaces rc!=0 errors
deterministically, ALWAYS isolates the parent
controlling-tty, and optionally live-relays the child's
std-streams to `log.<level>` per-line. Suits both
short-lived test-runners + long-lived daemons.
`supervise_run_process()`,
- Deterministic rc!=0: pass `check=False` to `trio`
and do our OWN post-drain rc-check from the
supervisor coro body AFTER `own_tn.__aexit__` — NOT
inside the internal nursery, since that would
race-cancel the still-draining relay reader and lose
stderr lines. (Re)build + raise a BARE
`subprocess.CalledProcessError`: `.stderr=` for
programmatic callers + an `add_note()`'d
`|_.stderr:` block for human teardown logs. No
nursery-eg-wrapped CPE to `collapse_eg` around.
- Parent controlling-tty isolation: `stdin=DEVNULL`
always, `stdout=DEVNULL` unless relayed/overridden
(via `stdout=` kwarg w/ `_UNSET` sentinel so explicit
`None` = inherit still works). Prevents a spawned
program from clobbering the launching tty's scrollback
w/ control-seqs.
- Live per-line relay: `relay_stdout=True`/
`relay_stderr=True` → relayed to `log.<relay_level>`
(default `'io'`, our custom level 21). Picked to sort
just above stdlib `INFO`=20 so it shows at usual
`info`/`devx` levels yet stays separately filterable;
`runtime`=15 was REJECTED as a default since it'd be
silently filtered at usual verbosity — footgun for
daemon supervisors whose whole point is visibility.
STREAMED, not buffered-until-exit.
- Non-blocking `tn.start()` semantics: live
`trio.Process` handed up via
`task_status.started()` immediately (else
`tn.start()` would block till child exit, losing
the long-lived-daemon use case). Supervise/relay bg
tasks run to completion in this coro.
- `**run_process_kwargs` forwarded verbatim (env, shell,
cwd, start_new_session, executable, ...); MANAGED keys
(`stdin`/`stdout`/`stderr`/`check`) win on conflict.
- Crash-handling layer intentionally NOT baked in —
compose `maybe_open_crash_handler()` ON TOP at the
call-site.
`_relay_stream_lines()` helper,
- Concurrent pipe-drain reader. MANDATORY whenever piping
w/o `capture_*` since nothing else drains the OS pipe —
child blocks on `write()` once kernel buf (~64KiB) fills
→ deadlock.
- Modes (combine freely): `emit`-only live relay,
`accum`-only silent drain+capture (for the CPE note),
or both. Per-line splitting handles cross-chunk
residuals + flushes any trailing un-newline-term'd line
at EOF.
`_add_stderr_note()` helper,
- Attaches an indented `|_.stderr:` note to a CPE via
`add_note()` for legible rc!=0 reporting at teardown.
Tests (`tests/trionics/test_subproc.py`),
- Hermetic `trio`-only (no actor-runtime).
- `test_stdout_relayed_per_line`: per-line stdout relay.
- `test_parent_tty_isolated`: child fd1 is OUR pipe (no
`/dev/pts/*`), fd0 pinned to `/dev/null`.
- `test_no_deadlock_on_big_unnewlined_output`: 200KiB
no-newline output completes under `fail_after(2)` —
exercises the concurrent drain (without it, the child
blocks at ~64KiB).
- `test_stderr_relay_and_cpe_rebuild`: rc!=0 w/
`relay_stderr=True` → bare `CalledProcessError` w/ the
`.stderr` note + per-line live relay.
- `test_nonrelay_cpe_note`: rc!=0 w/o relay → same
deterministic post-drain CPE w/ `.stderr` note (silent
drain+capture path).
Re-export `supervise_run_process` from `tractor.trionics`.
Prompt-IO: ai/prompt-io/claude/20260601T231429Z_0e3e008b_prompt_io.md
(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit f595acc76c)
(cherry picked from commit 6df9ee11bc)
Matches the explicit `dict.pop(uid, None)` contract one
line above; same semantics as the prior truthy check.
(this commit msg was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit 0e3e008b0c)
(cherry picked from commit 13ed668512)
The bound `StackLevelAdapter.<name>` emit method captured its
level via a `_level: int = value` default-arg at bind time, so
a later `add_log_level(name, <new-value>)` re-registration left
the method emitting at the *stale* original level. Read
`CUSTOM_LEVELS[name_up]` at call time instead — the method binds
once but always tracks the current registered value.
Also,
- correct the `add_log_level()` docstring's "Idempotent" note
to describe the call-time value lookup (was the misleading
"no-op-ish refresh (won't clobber an already-bound method)").
- sync stale `_reap.py` doc/comment markers `tractor[` ->
`_subactor[` to match the actual `_proctitle._def_prefix`
proc-title prefix (doc-only drift; the code markers already
referenced `_proctitle._def_prefix`).
Review: PR #467 (copilot-pull-request-reviewer)
https://github.com/goodboy/tractor/pull/467#pullrequestreview-4562945515
(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
Make the sub-actor proc-title prefix a single
authoritative constant (`_proctitle._def_prefix`) so
the reap-recognition markers and `xontrib` banner pick
it up automatically — one place to flip the prefix
shape going fwd.
Deats,
- `_proctitle._def_prefix: str = '_subactor'`. New
module-level const consumed by everything that needs
to know the prefix.
- `set_actor_proctitle(actor, prefix=_def_prefix)`:
takes an explicit `prefix` arg (default = the const)
so callers can override per-spawn if they want.
- Default proc-title format:
`'tractor[<reprol>]'` → `f'{prefix}[<reprol>]'`
i.e. `_subactor[<reprol>]` by default.
- `_testing/_reap.py`: cmdline + comm markers source
the prefix from `_proctitle._def_prefix` instead of
the hardcoded `'tractor['`. So
`_is_tractor_subactor()` tracks the const
automatically.
- `xontrib/tractor_diag.xsh`: `acli.reap` orphan-mode
banner now interpolates the
`_TRACTOR_PROC_CMDLINE_MARKERS` tuple directly so
the human-readable mode line stays in sync if the
prefix shape changes again.
(this commit msg was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit 3a45dbd503)
(cherry picked from commit fd8d39c0ce)
Follow-up to f595acc7 (`supervise_run_process`) which
called `log.io(...)` for std-stream relay assuming an
`IO=21` level existed. Add the registration via a new
factory + tests covering both the factory and the new
level.
`add_log_level()` factory,
- One call wires the four (otherwise hand-synced) pieces:
- `CUSTOM_LEVELS[NAME]` — drives the `stacklevel` bump
in `StackLevelAdapter.log()` + `get_logger()`'s
per-level audit.
- `logging.addLevelName()` — stdlib name registration.
- `STD_PALETTE[NAME]` + `BOLD_PALETTE['bold'][NAME]` —
color entries consumed by `get_console_log()`'s
`ColoredFormatter` build.
- Same-named (lowercase) emit method bound on
`StackLevelAdapter` so `log.<name>('msg')` works +
`get_logger()`'s per-level method audit passes.
- Idempotent: re-registering an existing name is a
no-op-ish refresh that won't clobber an already-bound
method.
- Method binding uses a default-arg `_level=value` so
the level int is captured (not late-bound across
multiple registrations).
`IO=21` level (first user),
- Purple. Used by `tractor.trionics._subproc`'s
std-stream relay (see f595acc7).
- Value 21 picked to sit just ABOVE stdlib `INFO`=20 so
it's SHOWN BY DEFAULT at usual `info`/`devx` console
levels — a `runtime`=15 relay would be silently
filtered (footgun for daemon supervisors whose whole
point is visibility). Still distinctly labeled +
filterable.
Tests (`tests/test_log_sys.py`),
- `test_io_custom_level_registered`: validates the IO
level is fully wired (`CUSTOM_LEVELS`, `addLevelName`,
both palettes, `StackLevelAdapter.io()` callable);
emits a record + sanity-asserts `21 >= INFO(20)`.
- `test_add_log_level_pluggable`: registers a fresh
`XLVL=19` (cyan) via `add_log_level()`, asserts all
four wires + the bound `xlog.xlvl()` emit, then
try/finally cleans up the module-global mutations so
later `get_logger()` audits don't trip on a
half-removed level.
(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit 7bd7dd50c7)
(cherry picked from commit 93558fe3c9)
The `'started' in rte.args[0]` check was too loose: it
matched a child task's OWN `RuntimeError(...started...)`
(not just trio's "child exited without calling
task_status.started()"), and would `TypeError` on a
non-`str` `args[0]`. Guard with `isinstance(..., str)` and
match trio's exact wording so a real child error can't be
demoted to `Cancelled` under cancellation.
Review: PR #464 (copilot-pull-request-reviewer)
https://github.com/goodboy/tractor/pull/464#pullrequestreview-4548203343
(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
`30e15925` ("Add `start_or_cancel()` to `trionics._taskc`")
inserted `async def start_or_cancel()` — whose body opens its
own col-4 `try:` — immediately before the trailing `else:
raise`. Because the edit was a pure insertion (0 deletions),
the *same* `else: raise` lines were silently REPARENTED: they
used to be the `for exc_match in matching: ... else: raise`
of `maybe_raise_from_masking_exc`, but now bind to
`start_or_cancel`'s `try/except` where they're unreachable
dead code.
Net effect: `maybe_raise_from_masking_exc` lost the `for/else`
re-raise of the un-masked exception, so a masked child
cancellation gets swallowed instead of surfaced.
- restore the `for/else: raise` to `maybe_raise_from_masking_exc`
- drop the now-dead `else: raise` from `start_or_cancel`
Surfaced as 2 deterministic failures in
`test_sigint_closes_lifetime_stack[wait_for_ctx-bg_aio_task-
send_SIGINT_to=child-*]` (the SIGINT-to-child "silent-abandon"
regime). Bisected with `trio` held at `0.29.0`: clean at
`9c36363b` (0/8), broken at `30e15925` (8/8), fixed (0/8).
NOT a `trio` (0.29↔0.33 identical) nor logging-plugin
regression.
(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit 325574cc07)
(cherry picked from commit 0b8033fdaa)
Wrapper around `trio.Nursery.start()` that DOESN'T mask
out-of-band cancellation as a lossy startup failure.
Picks the right re-raise: ambient `Cancelled` when
present, the genuine startup-protocol `RuntimeError`
otherwise.
The problem,
- `trio.Nursery.start()` raises a generic
`RuntimeError("child exited without calling
task_status.started()")` whenever the started task
exits BEFORE calling `task_status.started()` —
INCLUDING the common case where the child was
cancelled out-of-band by an *ancestor* cancel-scope
erroring/cancelling.
- In that case the original `trio.Cancelled` is
swallowed and the caller is left w/ an opaque,
root-cause-detached `RuntimeError`.
The fix,
- Catch the "...started" RTE.
- `await trio.lowlevel.checkpoint_if_cancelled()` —
re-raises the in-flight `Cancelled` IFF we're under
effective cancellation (ancestor-inclusive), carrying
trio's auto-generated reason which points at the true
root exc.
- If we're NOT cancelled the `checkpoint_if_cancelled()`
is a cheap no-op and we fall through to re-raise the
genuine startup-protocol RTE.
Re-export from `tractor.trionics` so callers don't have
to reach into `_taskc`.
(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit 30e15925ba)
(cherry picked from commit 2b4589b1ee)
All 5 flagged items were valid (4 real bugs + 1 dead assert),
- fix an inverted `sys.version_info < (3, 14)` guard in
`ipc._linux` — the "`cffi` has no 3.14 support" import note now
fires on 3.14+ (where it applies) instead of on older pys.
- use `os.environ.get('PYTHON_COLORS')` in the `sync_bp` example
so it doesn't `KeyError` when run outside the test harness.
- correct `dump_task_tree()`'s docstring: the `/tmp` + `/dev/tty`
tee is gated on `write_file`/`write_tty`, not "unconditional".
- tidy the `ActorTooSlowError` message spacing in `cancel_actor`.
- replace a tautological `applied is True or applied is False` in
`test_patches` with `isinstance(applied, bool)` (the value is
order-dependent across the module).
Review: PR #462 (copilot-pull-request-reviewer)
https://github.com/goodboy/tractor/pull/462#pullrequestreview-4527179852
(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
The `TRACTOR_LOGLEVEL`/`TRACTOR_SPAWN_METHOD` override-notice
branches were unreachable: `loglevel`/`start_method` were
reassigned to the env value BEFORE the `!=` compare, so the
"OVERRIDES caller-passed" message never fired. Capture the
caller value first, then compare. Rel. `208e7c09`/`d4eac06d`
"Honor env-vars" (`trionics.start_or_cancel`); surfaced by
`/code-review high` on #462.
(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
Two defensive fixes around the `Portal.cancel_actor()` +
`_try_cancel_then_kill()` escalation from `34f333a0`
"Escalate cancel-ack timeouts to `proc.terminate()`" (the
`trionics.start_or_cancel` follow-up); surfaced by
`/code-review high` on #462,
- guard `proc.terminate()` for backends whose `proc` slot
isn't a `Process` — the future `subint` backend stores an
`int` interp-id, so escalation would `AttributeError`
instead of hard-killing; now it logs + no-ops.
- swap `assert cs.cancelled_caught` for an
`if cs.cancelled_caught and raise_on_timeout:` guard so an
unexpected shielded-scope exit returns a soft `False`
rather than crashing `cancel_actor()` mid-teardown.
(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
Two fixes to the hang-debug SIGUSR1 task-tree dump path,
surfaced by `/code-review high` on #462,
- re-add `_debug_mode` to the sub-actor handler-install gate
in `_runtime.py`. Dropping it (rel. `3a386ba5`/`3d9c75b6`
"Drop debug_mode gate", from the `custom_log_levels_api`
follow-up) was meant to *also* enable non-pdb runs, but
nothing sets `use_stackscope` from `debug_mode`, so
debug-mode subs were left with NO handler — and the default
SIGUSR1 disposition then *kills* them. Now additive:
`_debug_mode OR use_stackscope OR env`.
- pass `write_file=True` at both `dump_task_tree()` SIGUSR1
call sites so the advertised `/tmp/tractor-stackscope-<pid>`
`.log` tee is actually written (was dead under
`--capture=fd`). Matches `1b1ef10a` "Re-enable writing
`stackscope` to file by default"; param from `0df90500`.
(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
Left-over debug trap from the `_runtime_vars` pure get/set
refactor — it fired on *every* struct-form rt-var write (e.g.
via `.update()`), hanging any non-tty / CI / forked actor on
`pdb` stdin.
Surfaced by a `/code-review high` pass on #462.
(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
`open_root_actor()` writes `_enable_tpts` (and friends) into
the process-global `_state._runtime_vars` dict but nothing
resets it on actor teardown. Under the in-proc `pytest`
launchpad a uds-using test leaks `_enable_tpts=['uds']` into
a sibling tcp test, tripping the
`registry_addrs`×`enable_transports` proto-guard in
`open_root_actor()` with a `ValueError`.
New `_reset_runtime_vars` fixture snapshots + restores the
dict around every test so no runtime-var state crosses a
test boundary.
(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
Strip the trailing `pkg_path` token ONLY when it duplicates the
caller's leaf-*module* name (which the console header already
shows via `{filename}`), instead of blindly dropping the last
token. This keeps genuine, possibly-*nested* sub-PACKAGE parts
addressable as their own sub-loggers.
- detect a true leaf-mod by comparing the caller's `__name__`
vs `__package__` (a pkg `__init__` has them equal -> its
trailing token is a real sub-pkg, NOT a leaf to strip).
- `name='devx.debug'` now -> `tractor.devx.debug`, DISTINCT
from a bare `devx` -> `tractor.devx`; the old unconditional
`pkg_path = subpkg_path` collapsed both to `tractor.devx` and
silently broke per-sub-pkg level control via the logging-spec.
- `get_logger(__name__)` leaf-strip still works (cosmetic, bc
the leaf-mod is in the `{filename}` header field).
Also,
- update the `LogSpec` caveat: sub-PACKAGE granularity now
addressable at ANY depth; leaf *modules* intentionally aren't
(they're the `{filename}`); top-level mods (eg. `to_asyncio`)
still emit on the root logger.
- adjust `test_root_pkg_not_duplicated_in_logger_name` to the
new literal explicit-`name` contract (no leaf-collapse).
(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit 9c36363b01)
Two coupled changes that let downstream projects (eg. `modden`) inherit
the test-harness loglevel plumbing for free via
`tractor._testing.pytest`:
Plugin lift (`tests/conftest.py` → `_testing/pytest.py`),
- mv `pytest_addoption(--ll)`, the `loglevel` autouse
fixture, and `test_log` fixture out of the test-suite-
local conftest into the reusable plugin.
- add `--tl`/`--tractor-loglevel` as a DISTINCT flag from
`--ll`: `--ll` is the consuming-project's OWN app
loglevel (scoped to its pkg-hierarchy), `--tl` is the
`tractor.*` runtime loglevel. `--tl` falls back to
`--ll` when unset (preserves current `tractor`-suite
behavior).
- add `testing_pkg_name` session fixture (default
`'tractor'`) — downstream projects override to e.g.
`'modden'` so `--ll` scopes to their own hierarchy
instead of `tractor.*`.
- `loglevel` fixture now yields the resolved
tractor-runtime level (passed to
`open_root_actor(loglevel=<.>)` by `@tractor_test`)
AND separately applies `--ll` to the
`testing_pkg_name` hierarchy when that isn't
`tractor`. `test_log` scopes the per-test logger to
`testing_pkg_name`.
`tractor.log` "logging-spec" mini-DSL,
- `LogSpec = str|bool`. Accepted forms:
- `True` → enable `pkg_name` root at `default_level`
(fallback `'cancel'`).
- `False` → no-op.
- bare level eg. `'info'` → root-logger at that level.
- `'sub:info,x:cancel'` → per-sub-logger filter-spec;
each `<name>` is RELATIVE to `pkg_name` (must NOT
include the pkg-token).
- `parse_logspec()` → `{sublog|None: level}` mapping.
`None` key = root-logger. Mixed bare-level + filters
in one spec is rejected w/ a helpful err msg; so is
embedding the `pkg_name` token in a sub-name.
- `apply_logspec()` → `(primary_level, {name: log})`:
parses then enables a `colorlog` stderr handler per
named (sub)logger. Authoritative sub-logger filters
get `propagate=False` so they don't double-emit
through a parallel root-level handler.
- !GRANULARITY CAVEAT! sub-logger names match at
sub-pkg granularity, not leaf-module — so `devx.debug`
collapses to the same `tractor.devx` logger as a bare
`devx`, and top-level lib modules (eg.
`tractor.to_asyncio`) emit under the *root* logger
rather than a phantom `to_asyncio` child. Documented
inline on `LogSpec`.
Other,
- `tests/conftest.py` keeps a NOTE pointing to the
plugin for future-debugging clarity (don't remove
silently — the lift is the relevant signal).
(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit 19a77708ba)
Factor the "deliver an exc to a running aio task" pattern out of
`translate_aio_errors()` + `open_channel_from()` into a shared
`maybe_signal_aio_task()` helper. Add a cause-chain matrix comment
+ relay-echo guard so the final-raise block can't cycle
`trio_err.__cause__` back onto its own derivative relay.
`maybe_signal_aio_task()`,
- Delivers `exc` via `aio_task._fut_waiter.set_exception()` — NOT
`aio_task.set_exception()` which on py3.13+ ALWAYS raises
`RuntimeError("Task does not support set_exception")` (dead code as
a relay mechanism).
- Returns `(delivered: bool, report: str)`. Caller uses `delivered` to
flip `wait_on_aio_task` when delivery failed (avoids hanging on
`_aio_task_complete.wait()`).
- `pre_captured_fut=`: required when the caller crosses a trio
checkpoint between capturing `_fut_waiter` and invoking the helper.
`Task._wakeup` clears `_fut_waiter = None` so re-reading
post-checkpoint loses the ref even though the exc is still in-flight
on the (now-`done()`) original fut.
- `cause=`: sets `exc.__cause__ = cause` so the relay carries
a "trio_err -> caused -> relay" chain through `set_exception()`
→ `Task._wakeup` → coro raise → `wait_on_coro_final_result`
→ `signal_trio_when_done` → `task.result()`-raise.
- `allow_cancel_fallback=True`: opt-in `aio_task.cancel()` for the
narrow case where `_fut_waiter is None` AND task is runnable (sitting
in asyncio's ready queue, not parked on a poke-able future). NEVER
cancels when `_fut_waiter` carries an in-flight exc — that would race
+ mask the real terminating exc.
`translate_aio_errors()`,
- Replace the two ad-hoc `_fut_waiter.set_exception()`
/ `aio_task.set_exception()` call sites w/ the helper.
- Capture `pre_cp_fut = aio_task._fut_waiter` BEFORE the post-shutdown
`trio.lowlevel.checkpoint()` (critical: `_wakeup` clears the ref).
- New "cross-loop cause-chain matrix" comment block on the final-raise
— tabulates every `(trio_err, aio_err, trio_to_raise)` combo into
exactly one terminal `raise X [from Y]` or early `return`. Covers the
sibling `signal_trio_when_done()` resolution + the relay-echo
INVARIANT.
- New relay-echo guard: if `aio_err` is one of OUR OWN signals
(`TrioTaskExited`/`TrioCancelled`) AND `aio_err.__cause__ is
trio_err`, raise the bare `trio_err` instead of `trio_err from
aio_err` (which would CYCLE the cause chain since the relay was itself
caused-by `trio_err`).
- Drop the stale "the `task.set_exception(aio_taskc)` call MUST NOT
EXCEPT or this WILL HANG" warning — the helper handles the failure
path explicitly via `delivered=False` → `wait_on_aio_task = False`.
- Carry `cause=trio_err` on both the cancel-relay (`TrioCancelled`) and
the graceful-exit relay (`TrioTaskExited`) so the aio-side traceback
shows the real root.
`open_channel_from()`,
- Adopt the same helper; drop the dead "SHOULD NEVER GET HERE !?!?"
+ `tractor.pause(shield=True)` panic branch.
- Capture in-flight trio-side exc via `sys.exc_info()[1]` and pass as
`cause=` — non-`None` only when the `try` body raised (graceful exit
→ None).
Other,
- Top-level import: `sys` (for `sys.exc_info()`).
- `run_as_asyncio_guest()`: add commented-out alt `out: Outcome = await
trio_done_fute` next to the shielded version — exploratory note for
the longstanding "why is `.shield()` needed?" TODO.
(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit acd1cbeec4)
SIGUSR1 task-tree dumps via `stackscope` should work in
plain (non-pdb) runs too — esp. in infected-`asyncio`
processes where the kernel-default SIGUSR1 disposition is
`Term` (proc dies on `kill -USR1` w/o an installed
handler). Ungate the install path from `_debug_mode` in
both root and sub-actor init; the `use_stackscope` rt-var
+ `TRACTOR_ENABLE_STACKSCOPE` env-var checks remain as
the actual opt-in (e.g. via `--enable-stackscope`).
Deats,
- `_root.open_root_actor`: drop the `debug_mode and ...`
conjunction around the `enable_stack_on_sig()` call;
now gated only on the `enable_stack_on_sig` arg itself.
- `_runtime.Actor` sub-actor init: lift the
`use_stackscope`/`TRACTOR_ENABLE_STACKSCOPE` branch out
of the `if rvs['_debug_mode']:` block to peer-level.
The `use_greenback` branch stays inside `_debug_mode`
(pdb-specific).
- Refresh inline comments on both sites to call out the
infected-`asyncio` "default SIGUSR1 = terminate proc"
rationale.
(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit 3d9c75b6ed)
Only flag `tractor._child` procs as cross-test ghosts of
THIS run if `ppid==1` (init-adopted real leak) or `ppid`
is in the walk's `seen` set (descendant we missed via
race).
Previously, procs whose `ppid` points to some OTHER live non-`pytest`
(in the use of `acli.ptree pytest`) process belong to a different
tractor app (`piker`, another `pytest` shell, a long-running tractor
daemon) and were being falsely flagged as cross-test ghosts.
Deats,
- post-cmdline-match check via `_ppid_from_proc(pid)`,
short-circuit on `None` (proc died in-flight).
- expand module docstring to spell out the ownership
filter rule + its rationale.
(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit a6d4ac3aac)
Post-yield now also reaps init-adopted (`ppid==1`) tractor procs
that appeared during the test — leaked subactors whose mid-tier
parent died during cascade teardown, reparenting them to init.
Pre-yield snapshot of existing orphans scopes reap to THIS test's
leaks only, avoiding reap of unrelated tractor uses (piker, etc.)
on the box.
(this commit msg was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit 01ce2857ea)
`reap(include_descendants=True)` now expands each orphan-root pid
into its full psutil subtree before delivering SIGINT, so a
multi-level leaked actor-tree gets torn down in a single pass
instead of requiring repeated calls (each pass kills the current
`ppid==1` level, the level below becomes init-adopted, etc.).
Falls back to the original flat `pids` list when `psutil` is
unavailable. Emits a log line when expansion adds descendant pids.
(this commit msg was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit 8de684f5de)
- `_testing/trace.py`: add `_SNAPSHOT_INDEX` session- scoped list
populated by `_do_capture_snapshot()` on each successful dump;
add TODO for future `TRACTOR_TRACE_HOLD=1` pause-on-hang mode
- `_testing/pytest.py`: add `pytest_terminal_summary` hook that
prints all captured snapshot dirs at end-of-session so paths
don't get buried in scrollback
(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit fb87c36263)
Deats,
- `_find_tractor_strays()`: scan `/proc/*/cmdline` for
`tractor._child` procs NOT in the walk's `seen` set — surfaces
ghost subactor trees from prior test runs (cross-test launchpad
contamination).
- `dump_proc_tree(include_strays=True)`: refactor classification
into `_classify_walk()` closure, walk stray roots as additional
trees, emit stray-root summary in header. Also: `tractor._child`
procs reparented to init are now always classified as orphans
regardless of cgroup-slice (leaked subactor ≠ desktop-launched
app).
- `_do_capture_snapshot()`: use `sys.__stderr__` to bypass pytest
`--capture=sys` redirection so snapshot paths always land on the
real terminal
- `fail_after_w_trace()`: capture diag snapshot on
non-`TooSlowError` exceptions when the `fail_after` scope's
cancel had already fired (e.g. nursery wraps `Cancelled` into a
`BaseExceptionGroup` that escapes before `TooSlowError` can be
raised).
(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit 3a243a1fd4)
Extract all pure-Python diagnostic helpers (`dump_proc_tree`,
`dump_hung_state`, `scan_bindspace`, `dump_all`, `resolve_pids`,
`ensure_sudo_cached`, etc.) from the xonsh xontrib into a new
`tractor/_testing/trace.py` module so the same logic is callable
from both the `acli.*` terminal aliases AND in-test capture-on-hang
fixtures.
Deats,
- `_testing/trace.py`: new module (1171 lines) — proc-tree walker,
hung-state dumper, bindspace scanner, `dump_all()` snapshot
archiver, `AFKAlarmTimeout` exc, `fail_after_w_trace()` async CM
(trio `fail_after` + auto-snapshot on `TooSlowError`),
`afk_alarm_w_trace()` sync CM (`signal.alarm` + snapshot on
`SIGALRM`), plus pytest fixture wrappers for both.
- `_testing/pytest.py`: re-export the two fixtures via `from .trace
import` so pytest plugin-discovery picks them up.
- `tractor_diag.xsh`: thin terminal wrappers that import from
`_testing.trace` — drops ~627 lines of inline impl. Add
`acli.dump_all` alias for full snapshot-bundle CLI access.
(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit 7509e313ff)
Forking spawner + UDS transport has different timing
vs `trio_proc` — streaming example completes faster
in some cases, slower in others depending on fork
overhead + sock setup.
Deats,
- add `expect_cancel` param to `cancel_after()`, raise
`ActorTooSlowError` when cancel scope fires unexpectedly instead of
silently returning `None`.
- `time_quad_ex` fixture: bump timeout +1 for forking+UDS, explicit
`ActorTooSlowError` on `None` result instead of bare `assert results`.
- `test_not_fast_enough_quad`: `xfail` for forking+UDS being "too fast"
(cancel doesn't fire bc streaming finishes before delay).
- add `is_forking_spawner`, `tpt_proto` fixture params throughout.
Also,
- `_testing/pytest.py`: widen `start_method` parametrize and
`is_forking_spawner` fixture to `scope='session'`.
- `"""` -> `'''` docstring style throughout.
- hoist `_non_linux` to module scope (was redefined locally in two
places).
- type hints, kwarg-style `partial()` calls.
(this commit msg was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit d3cbc92751)
Rework reap/diag tooling to identify tractor sub-actors via
intrinsic proc signals — cmdline/comm markers from `setproctitle` —
instead of env-var or cwd matching.
Deats,
- new `_is_tractor_subactor()` checks cmdline for `tractor[` /
`tractor._child` markers, falls back to `/proc/<pid>/comm` for
zombie-resilient detection (kernel preserves `comm` past exit
until reap)
- `_read_comm()` reads kernel per-task name set by `setproctitle()`
— the zombie-safe ID signal
- `_read_status_state()` reads single-letter proc state from
`/proc/<pid>/status` (`Z` = zombie)
- `find_orphans()` drops `repo_root` requirement, uses
`_is_tractor_subactor()` for intrinsic sub-actor ID instead of
cwd coincidence-matching
- new `find_zombies()` with optional `parent_pid` filter for
zombie-state sub-actors
Also,
- rename `pytree` -> `ptree` throughout xontrib
- add `_which_cgroup_slice()` — reads `/proc/<pid>/cgroup` to
distinguish `system.slice` services vs `user.slice` desktop apps
from genuinely leaked orphans
- `_ptree` classifies `ppid==1` procs into `system-slice`,
`user-slice`, and `orphans` buckets with per-section output
- `_tractor_reap` drops `git rev-parse` / `sys.path` hack — assumes
tractor importable from active venv
(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit 522b57570b)
New `tractor.devx._proctitle` mod sets each
sub-actor's `argv[0]` (and kernel `comm`) to
`tractor[<aid.reprol()>]` — e.g.
`tractor[doggy@1027301b]` — so `ps`/`top`/`htop`
and `acli.pytree`/reaper tooling can identify
actors at a glance without parsing full cmdlines.
Deats,
- `set_actor_proctitle()` wraps the `setproctitle`
pkg with `ImportError` guard; optional at runtime
but listed in `pyproject.toml` so default installs
benefit.
- called early in `_child._actor_child_main()` after
`Actor` construction, before `_trio_main()` entry.
- tests in `tests/devx/test_proctitle.py`: format
unit test, `/proc/{cmdline,comm}` integration
test, negative detection test.
Resolves#457
(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit d60245777e)
Wires SC-discipline cancel-then-escalate into
`ActorNursery.cancel()`:
graceful cancel-req -> bounded wait -> hard-kill
Deats,
- add `raise_on_timeout: bool = False` kwarg to `Portal.cancel_actor()`.
When `True`, bounded- wait expiry raises `ActorTooSlowError` instead
of the legacy DEBUG-log + return-`False` path. Default stays `False`
for callers that handle their own escalation (e.g.
`_spawn.soft_kill()` polling `proc.poll()`).
- add `_try_cancel_then_kill()` helper in `_supervise` used by per-child
cancel tasks. On `ActorTooSlowError`, escalates via `proc.terminate()`
(SIGTERM) so a non-acking sub doesn't park `soft_kill()` forever
waiting on `proc.poll()`.
- replace `tn.start_soon(portal.cancel_actor)` in
`ActorNursery.cancel()` with the helper.
Debug-mode bypass:
-----------------
skip escalation (fall back to legacy fire-and-forget cancel) when ANY
of:
- `Lock.ctx_in_debug is not None` (some actor is currently
REPL-locked)
- `_runtime_vars['_debug_mode']` (root opened with `debug_mode=True`).
- `ActorNursery._at_least_one_child_in_debug` (per-child `debug_mode=`
opt-in).
ORing covers root-debug, child-debug, and active- REPL-lock cases
without false-positively SIGTERM- ing a sub-tree proxying stdio for
a REPL session.
Motivated by the `subint_forkserver` dup-name hang where a same-named
sibling subactor's cancel-RPC failed to ack within
`Portal.cancel_timeout` (TCP+ forkserver register-RPC contention) and
the nursery `__aexit__` deadlocked.
(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit 34f333a026)
Distinct from `trio.TooSlowError` so that existing
`except trio.TooSlowError:` blocks don't silently
mask actor-cancel timeouts — these must propagate
to let a supervisor escalate to
`proc.terminate()` per SC-discipline:
graceful cancel-req -> bounded wait -> hard-kill
Motivated by #subint_forkserver dup-name hang
where `Portal.cancel_actor()` silently swallowed
the timeout and the supervisor never escalated,
leaving a same-named sibling subactor parked
forever.
(this commit msg was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit 38ffb875bd)
Pre-compute `mismatch_lines` str instead of `+`-concat
inside the f-string raise site; slightly easier to read
and avoids the `+ '\n\n'` continuation.
(this commit msg was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit 5cd06810db)
Refactor `pytest_load_initial_conftests()` to split
the fork-spawn × capture-mode check into two policies:
- CI (`CI` env-var set): `pytest.exit(rc=2)` on
mismatch — forces every matrix-row to declare
`--capture=sys` explicitly.
- local: `warnings.warn()` + continue — lets devs
experiment with `--capture=fd` to validate fixes.
Deats,
- drop `_cap_fd_set` global; add
`_CAPSYS_REQUIRED_SPAWNERS` frozenset for the
spawner-name lookup
- move inline comment wall → proper docstring w/
Background, Trade-off, Validation-policy sections
- `maybe_xfail_for_spawner()` now takes
`request: pytest.FixtureRequest` and reads
`request.config.option.capture` instead of the
`_cap_sys_passed_as_flag` global
- recognize `tee-sys` as fork-safe (only `fd`-level
capture deadlocks)
- `set_fork_aware_capture()` returns the actual
capture mode str from config, not a hardcoded
`'sys'`
- lift `import warnings` to module level (was duped
inside `pytest_configure`)
(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit 255c9c3a7c)
Raise `ValueError` from `open_root_actor()` when any
`registry_addrs` entry uses a transport proto not in
`enable_transports` — historically this caused a
silent indefinite hang during the registrar handshake
(the actor could never connect to register/discover).
Also,
- update `test_root_passes_tpt_to_sub` to detect a
proto mismatch between parametrized `tpt_proto_key`
and CLI `tpt_proto`, asserting the new guard raises
`ValueError` with expected msg content.
- replace old commented-out notes with a clearer
explanation of the mismatch foot-gun.
(this commit msg was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit d036ef7d7f)
Wrap `os.unlink()` in `close_listener()` with a `FileNotFoundError`
guard — under concurrent pytest sessions the sock-file can already be
reaped. Without this the raise aborts `_serve_ipc_eps`'s finally before
`_shutdown.set()`, deadlocking `wait_for_shutdown()` on
`actor.cancel()`.
Also,
- close each endpoint independently in the finally so one raise doesn't
strand the rest.
- always signal `_shutdown.set()` regardless of remaining ep count.
(this commit msg was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit 2ee44a6fdd)
Rename `_track_orphaned_uds_per_test` and
`_detect_runaway_subactors_per_test` to public names (drop `_` prefix),
drop `autouse=True`. Tests that need per-test reap blame now opt in via
`pytestmark = pytest.mark.usefixtures(...)`.
Also,
- reduce `sample_interval` from 0.5 -> 0.05s so the CPU probe is cheaper
per pid.
- add empty-`only_pids` fast-path in `find_runaway_subactors` to skip
psutil import when no descendants were spawned.
- extract `new_pids` intermediate var for clarity.
(this commit msg was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit e4953851de)
With a seminal patch fixing `trio`'s `WakeupSocketpair.drain()` which
can busy-loop due to lack of handling `EOF`.
New `tractor.trionics.patches` subpkg housing defensive monkey-patches
for upstream `trio` bugs we've encountered while running `tractor`
— particularly as of recent, fork-survival edge cases that haven't been
filed/fixed upstream yet. Each patch is idempotent, version-gated via
`is_needed()`, and carries a `# REMOVE WHEN:` marker pointing at the
upstream release whose adoption allows deletion.
Subpkg layout + per-patch contract documented in
`tractor/trionics/patches/README.md` — `apply()` / `is_needed()`
/ `repro()` API, registry pattern via `_PATCHES` in `__init__.py`,
single-call entry point `apply_all()`.
First patch, `_wakeup_socketpair`:
- `trio`'s `WakeupSocketpair.drain()` loops on `recv(64KB)` and exits
ONLY on `BlockingIOError`, NEVER on `recv() == b''` (peer-closed FIN).
- under `fork()`-spawning backends the COW-inherited socketpair fds
& `_close_inherited_fds()` teardown can leave a `WakeupSocketpair`
instance whose write-end is closed, and `drain()` then **spins forever
in C with no Python checkpoints**,
- this obviously burns 100% CPU and no signal delivery.
Standalone repro:
from trio._core._wakeup_socketpair import WakeupSocketpair
ws = WakeupSocketpair()
ws.write_sock.close()
ws.drain() # spins forever
Patch is one-line — break the drain loop on b'' EOF.
Manifested as two distinct test failures:
- `tests/test_multi_program.py::test_register_duplicate_name` hung at
100% CPU on the busy-loop directly (fork child's worker thread)
- `tests/test_infected_asyncio.py::test_aio_simple_error` Mode-A
deadlock — busy-loop wedged trio's scheduler inside `start_guest_run`,
both threads parked in `epoll_wait`, no TCP connect-back to parent
ever happened.
Same patch fixes both. Restored 99.7% pass rate on full
suite under `--spawn-backend=main_thread_forkserver`
(was hanging indefinitely before).
Wired into `tractor._child._actor_child_main` via `apply_all()` BEFORE
any trio runtime init. Harmless on non-fork backends.
Conc-anal write-ups, including strace + py-spy evidence:
- `ai/conc-anal/trio_wakeup_socketpair_busy_loop_under_fork_issue.md`
- `ai/conc-anal/infected_asyncio_under_main_thread_forkserver_hang_issue.md`
Regression tests in `tests/trionics/test_patches.py`: each test asserts
(a) the bug exists pre-patch (or is fixed upstream — skip cleanly), (b)
the patch fixes it with a SIGALRM wall-clock cap so a regression hangs
loud instead of silently.
TODO:
- [ ] file the upstream `python-trio/trio` issue + PR.
- [ ] use the `repro()` callable in `_wakeup_socketpair.py` IS the issue
body's evidence section.
(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit 0ef549fadb)
(factored: dropped spawn-backend-only paths: ai/conc-anal/infected_asyncio_under_main_thread_forkserver_hang_issue.md)
Inside a new new `tractor.spawn._reap` submod which kicks off providing
post-mortem subactor cleanup primitives, parent-side; consider it the
"sibling" of `tractor._testing._reap` which is the test-harness-oriented
brother mod.
Today: `unlink_uds_bind_addrs()` provides a starter bug-fix for #454
where `hard_kill()`'s `SIGKILL` bypasses the subactor's
`_serve_ipc_eps`-`finally:` `os.unlink(addr.sockpath)`, leaking
`${XDG_RUNTIME_DIR}/tractor/<name>@<pid>.sock` files..
This adds 2 cleanup paths:
- explicit `bind_addrs` (when set at spawn time),
OR
- convention-based reconstruction from `subactor.aid.name + proc.pid`
for the random-self-assign case.
`.spawn.hard_kill()` now invokes the cleanup unconditionally
post-`SIGKILL`; graceful-exit case is a no-op via `FileNotFoundError`
skip.
Future work — authoritative tracking via a per-process
UDS bind-addr registry — documented in module docstring,
deferred to a follow-up PR.
Co-fix: `tractor/spawn/_trio.py::new_proc` already passes
`bind_addrs` + `subactor` to `hard_kill` via prior work
on this branch.
(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit e9712dcaeb)
New `find_runaway_subactors()` helper + autouse
`_detect_runaway_subactors_per_test` fixture that
samples `psutil.cpu_percent()` on descendants to
catch tight-loop bugs (e.g. #452-class `recvfrom`
on a closed socket). Checks both at setup
(leftovers from a prior hung test) and teardown
(spawned by this test).
Intentionally does NOT kill the runaway — emits
a loud warning with diag commands (`strace`,
`lsof`, `ss`, `kill`) so the pid stays alive for
hands-on investigation. Session-end reaper still
SIGINT/SIGKILL survivors on normal exit.
(this commit msg was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
(cherry picked from commit 5cf0312c78)
Gud Boi