For each issue anchor present in BASE 63279301bc non-test .py and absent on HEAD, the BASE comment/docstring block was re-attached at the HEAD location of the code it explained (matched by the distinctive code line / enclosing def). Sentences already covered by an existing HEAD comment were deduped; the issue number always survives. Insert-only: no code lines changed.
A fan-out of N in-process subagents used to add one sleeping daemon
thread per delegated child (delegate heartbeat, 30s) and one or two per
active turn (durable turn-lease refresher; turn-liveness watchdog). A
profiled session with ~130 children was carrying ~1000 threads. All
of these timers now run on a single process-wide daemon thread.
- agent/periodic_scheduler.py (new): heap-ordered periodic scheduler on
one Condition-driven daemon thread. schedule(fn, interval) -> handle;
handle.cancel(wait=) blocks for an in-flight run like the old join.
A callback returning False stops itself; a raising callback is logged
at debug and rescheduled, so one bad timer cannot kill the rest.
- tools/delegate_tool.py: _heartbeat_loop body -> _heartbeat_tick,
scheduled at _HEARTBEAT_INTERVAL; stale-cycle closure state and
idle/in-tool thresholds unchanged; cancel(wait=5) in finally where the
stop-event + join(5) lived.
- run_agent.py: _refresh_durable_turn_lease body scheduled at
_lease_refresh_interval; lease-lost / refresh-error interrupt paths
and the stop-event fencing are unchanged; the join(timeout=1.0) is now
cancel(wait=1.0) so the interrupt clear still runs after any in-flight
tick.
- agent/turn_liveness.py: TurnLivenessWatchdog.make_thread/start ->
schedule(); the poll body is _tick(), same sampling state machine.
Bench (evals/fanout_resource_bench.py, 30 children / 10 worktrees,
ok=30/30 both): peak threads 168 -> 132. At peak the old tree held 30
"Thread-N (_heartbeat_loop)" threads; the new one holds zero plus one
"hermes-periodic-scheduler".
- deadline: _result()/_abandon() replace 7 BoundedResult constructions and 2
cancel+callback sites; timers handled as a list; dead raise_if_timed_out removed.
- file_safety: retired classify_cross_profile_target (0 refs; get_cross_profile_warning
stub kept for external callers), _home_and_resolved/_mirror_warning shared by
the sandbox/container mirror guards; _find_sandbox_mirror_segments inlined.
- estop: _hermes_home/_canonical_root now the file_safety helpers;
_reset_log_state_for_tests inlined into its only test.
- subagent_lifecycle: _validate_request driven by _UNSUPPORTED_REQUEST_FIELDS table.
- turn_liveness: dead start()/_abort_message removed, _emit_warning shared.
- process_bootstrap: _enable_happy_eyeballs reused by the client variant.
- Comment/docstring compaction across the remaining leaf modules.
Closes the #95663 round-8 review blocker (false settlement before
commit veto): the pre-commit surface (`_surface_stall`) logged
"Force-aborting the turn and stopping lease renewal" and warned the
user "aborting it so the session can recover" BEFORE `_commit_abort`
could veto — so a turn that resumed during the warning window (or an
exceptional interrupt path that declines fail-closed) was reported as
force-aborted with lease stopped while it actually continued running.
- Split the surface: `_surface_stall` is now observational only ("no
progress for Ns; attempting recovery"), and the definitive
aborted/lease-stopped settlement moves to a new
`_surface_committed_abort` that runs only after `_commit_abort`
succeeds and the turn lease is deactivated.
- Rate-limit repeated pre-commit surfaces per observed generation: a
turn whose aborts keep declining no longer re-logs an ERROR and
re-warns the user every poll interval.
- Add the committed-path regression test
(`test_watchdog_publishes_definitive_settlement_only_after_commit`)
and extend the declined-path witness
(`...resumes_during_warning`) to assert no committed-abort or
definitive pre-commit claim appears when the abort is vetoed. Both
fail on the pre-fix tree (mutation-checked).
- Document the `_interrupt_turn` lease-loss asymmetry (fires
unconditionally, no generation claim — losing the lease means the
process no longer owns the session).
- Trim review-round archaeology from comments/docstrings (keep the
WHY, drop the round numbering), and drop the dead
`cancel_event` compat note from the test fence.
- Document `agent.turn_liveness` in the configuration guide.
On top of PR #95663 by Finn763 (cherry-picked with authorship
preserved).
Add a turn-liveness watchdog keyed to the agent activity clock: a turn
that stalls mid-flight while the durable lease keeps renewing is logged
loudly, surfaced to the UI, force-interrupted, and — when the hard
interrupt cannot unwind the wedge — lease renewal is stopped so
stale-turn cleanup can reclaim the session.
Race safety (rounds 3/4/6 of the #95663 review, all folded into this
squashed commit):
- AIAgent.interrupt(require_generation=G) re-validates the generation
claim at the last instant before the hammer; a stale claim abandons
the abort and the turn continues.
- The claim is reserved under the activity lock, invalidated by any real
progress in _touch_activity(), and consumed immediately before the
first observable interrupt publication; exceptional paths fail closed.
- Claim consumption and the first interrupt publication are atomic
inside one _liveness_activity_lock() critical section; unclaimed
interrupts publish lock-free so AIAgent stand-ins without the liveness
seam keep working (CI 33096454629 regression, fixed here).
Deterministic race regressions (written red-first) in
tests/run_agent/test_turn_liveness_watchdog.py cover the
post-revalidation window, the consume-to-publication window, the
exceptional path, and atomic claim consumption.
Round-7 rebuild: single squashed commit on current origin/main; the
former four-commit lineage (241f8e484..299122558 on merge base
6defe7eb6c) no longer exists, so no surviving commit carries a red
exact-object CI record, and no empty CI-trigger commit was added.
