tractor/ai
Gud Boi f3cea714bc Expand `subint` sigint-starvation hang catalog
Add two more tests to the catalog in
`conc-anal/subint_sigint_starvation_issue.md` — same
signal-wakeup-fd-saturation fingerprint (abandoned legacy-subint driver
threads → shared-GIL starvation → `write() = EAGAIN` on the wakeup pipe
→ silent SIGINT drop), different load patterns.

Deats,
- `test_cancel_while_childs_child_in_sync_sleep[subint-False]`: nested
  actor-tree + sync-sleeping grandchild. Under `trio`/`mp_*` the "zombie
  reaper" is a subproc `SIGKILL`; no equivalent exists under subint, so
  the grandchild persists in its abandoned driver thread. Often only
  manifests under full-suite runs (earlier tests seed the
  abandoned-thread pool).

- `test_multierror_fast_nursery[subint-25-0.5]`: 25 concurrent subactors
  all go through teardown on the multierror. Bounded hard-kills run in
  parallel — so the total budget is ~3s, not 3s × 25. Leaves 25
  abandoned driver threads simultaneously alive, an extreme pressure
  multiplier. `strace` shows several successful `write(16, "\2", 1) = 1`
  (GIL round-robin IS giving main brief slices) before finally
  saturating with `EAGAIN`.

Also include a `pstree -snapt <pid>` capture showing
16+ live `{subint-driver[<interp_id>}` threads at the
moment of hang — the direct GIL-contender population.

(this commit msg was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
2026-04-23 18:47:49 -04:00
..
conc-anal Expand `subint` sigint-starvation hang catalog 2026-04-23 18:47:49 -04:00
prompt-io Add prompt-io log for `subint` hang-class docs 2026-04-23 18:47:49 -04:00