Implements the resolution described in c99d475d's
`subint_forkserver_mp_shared_memory_issue.md` (now
updated with the resolution post-mortem). Two-part
fix that side-steps `mp.resource_tracker` entirely
rather than try to make it fork-safe — turns out
that's both simpler AND more correct given tractor
already SC-manages allocation lifetimes.
Deats,
- `tractor/ipc/_mp_bs.py::disable_mantracker()`: drop the
`platform.python_version_tuple()[:-1] >= ('3', '13')` branch — patches
now run unconditionally:
* monkey-patch `mp.resource_tracker. _resource_tracker` to a no-op
`ManTracker` subclass (empty `register` / `unregister`
/ `ensure_running`).
* return `partial(SharedMemory, track=False)` for the per-allocation
opt-out.
* belt + suspenders: even if something dodges the wrapper, the
singleton can't talk to the inherited (broken) parent fd.
- `tractor/ipc/_shm.py::open_shm_list()`: drop the 3.13+ conditional
skip of the unlink-callback; install a `try_unlink()` wrapper that
swallows `FileNotFoundError` (sibling-already-cleaned race in
shared-key setups). Without `mp.resource_tracker` doing it for us, we
own the unlink — `actor. lifetime_stack` is the right place since
tractor already controls actor lifecycle.
- `tests/test_shm.py`: uncomment-out `subint_forkserver` from the
module-level skip- list (tests pass now). Inline comment cross-refs
the two `_mp_bs` / `_shm` workarounds.
- `ai/conc-anal/subint_forkserver_mp_shared_memory_ issue.md`: heavy
rewrite — flips status from "open / unresolvable in tractor" to
"resolved, kept as decision record". Adds Resolution section, "Why
this is the right call" rationale (mp tracker is widely criticized;
tractor already owns lifecycle), trade-offs (crash-leaked segments,
lost mp leak warning), verification (7 passed under both
`subint_forkserver` and `trio` backends), and upstream issue links
(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code