4.7 KiB
Prompt
Implementation-purpose summary, not a verbatim human prompt:
Implement only the approved shielded-child/stalled-IPC followup in the existing ipc_fault_regressions worktree. Add a seventh case with both parent context directions stalled, a child task shielding outer cancellation, and usable subactor control IPC. Prove readiness, received cooperative cancellation, finite budget expiry, runtime SIGKILL and parent OS reaping. Preserve existing six-case semantics, user-owned files, index and Git history.
Response summary
probe_peer() optionally enters trio.CancelScope(shield=True) before Context.started(). Its stdout event later observes both Actor._cancel_called and cancelled outer Context._scope while the inner shield remains uncancelled. No production instrumentation is needed: Actor.cancel() calls Actor.cancel_rpc_tasks(), whose Actor._cancel_task() cancels Context._scope and waits for RPC completion. The inner shield prevents that completion.
root_main() stalls both OOB context directions, completes a control RPC using untouched staller_ptl, and reports its finite Portal.cancel_timeout. The external monitor sends actual SIGINT only after both parked-operation and child-shield readiness. The seventh case requires the child’s pending-cancel observation, runtime cancel-ack timeout and hard-reap logs, SIGKILL status and existing parent os.waitpid() proof before watchdog cleanup.
Files changed
examples/advanced_faults/ipc_stalls.py: seventh mode, child shield and evidence, control usability check, mode documentation.tests/test_ipc_stalls.py: seventh parameter, CASE explanation, event ordering checks and mode-specific hard-reap expectations.- This new structured provenance pair; previous records untouched.
Verification
Interpreter:
/home/goodboy/repos/tractor/wkts/ib_disconnect_cleanup/py313/bin/python
Trio version: 0.34.0. Import probe confirmed tractor resolves inside ipc_fault_regressions. Per-process PYTHONPATH entries:
/home/goodboy/repos/tractor/wkts/ipc_fault_regressions/home/goodboy/repos/tractor/wkts/ib_disconnect_cleanup/py313/lib/python3.13/site-packages/nix/store/l59n6vzkswz23y6s4pr6cmv2p4dpd5f0-python3.13-numpy-2.4.4/lib/python3.13/site-packages
PYTHONDONTWRITEBYTECODE=1; no installed dependencies changed.
First run:
python -m pytest tests/test_ipc_stalls.py -q -p no:tractor._testing._reap
Result: 7 passed in 14.21s, no skips or failures.
Second run, in a fresh process:
tests/devx/test_tooling.py::test_shield_pause
Flags: -q -p no:tractor._testing._reap --spawn-backend=trio. Result: 1 passed, 1 warning in 2.65s, no skips or failures. The warning was PytestAssertRewriteWarning because the in-memory launcher imported tractor._testing before pytest.main().
The tooling fixture’s mk_cmd() normally uses bare python and launches an example with a default registry. An in-memory override used the specified absolute interpreter and runpy.run_path(); it bound tractor.open_nursery with functools.partial to a unique get_rando_addr('uds') address and ensure_registry=True. No test or example file was changed for this existing tooling invocation. Only the tooling test’s owned process handles were signalled.
git diff --check passed. Source lines follow the 69-column style.
Human contributions
The human endorsed the shielded-child/stalled-IPC followup with “right, exactly what i was thinking” and “sounds good lfg!”, then asked to “gen me a handoff for an agent there to review from your work.” Detailed implementation constraints came through internal agent delegation; they are not verbatim human instructions. No direct manual source edits during this interaction were observed. Acceptance remains with the human.
Internal agent delegation text was originally mislabelled as human instruction; corrected during review. The private original is retained under ignored review runtime at .claude/review_replies/shield_review5/.
Proof limits
This exercises test-owned Trio task resistance to outer cancellation with cancellable parent-side transport waits, Linux, TCP context IPC and the Trio spawner. It does not model an uninterruptible kernel syscall, full socket buffering, packet loss or half-open TCP. Budget expiry is evidenced by the production cancel-ack timeout diagnostic; no synthetic send-deadline metric is claimed for this usable-control-channel case. Both existing and new assertions run before failure-only external watchdog rescue.
No core runtime gap was observed. Production runtime is unchanged.