An open chat window took a session-cap slot at session.create/resume time.
Every desktop tile paint and every background reconnect-resume opens one, so
on a websocket-flappy host they accumulated: five parked desktop tabs filled a
5-slot cap and locked the messaging gateway (which shares the cap) out for
fourteen minutes while running no agents at all.
A slot held that way is invisible everywhere. An unprompted draft has no DB row
and the sidebar filters it out with min_messages=1, so the only way to diagnose
it was reading runtime/active_sessions.json by hand.
Claim on the first turn instead, mirroring the lazy contract
_ensure_session_db_row already uses for the row itself. Capacity now means an
agent can run rather than that a window exists, and anything holding a slot is
something the user can see.
Also reclaim leases whose session skipped teardown. _prune_dead only fires when
the owning pid dies, and a dashboard/serve backend runs for days, so a leaked
lease was held until restart. The owning process reconciles against the leases
it still holds, which is exact and needs no heartbeat write on the turn path.
When a session rotates id on compression, _sync_session_key_after_compress()
re-anchored the session_key, approval-notify routing, yolo state, and slash
worker — but never moved the active-session lease, which stayed keyed to the
pre-compression id. And _find_live_session_by_key() matched live sessions on
the stale session_key, not the live agent's current agent.session_id. After
compression a resume/create path failed to recognize the existing live agent
and could build a SECOND live agent against the same DB continuation -> forked
lineage / cross-session message mixing.
- active_sessions.transfer_active_session(): move a lease in place to the new
id under the exclusive file lock (no slot drop).
- gateway _transfer_active_session_slot(): call it inside
_sync_session_key_after_compress(); on the rare fallback (entry pruned)
RESERVE the new slot before releasing the old lease (reserve-before-release),
so a concurrent gateway at the session cap cannot grab the freed slot in a
release-then-reacquire window and leave this session with no lease; if the
reserve fails, keep the existing lease (review fix).
- _session_lookup_key(): make live-session lookup authoritative on
agent.session_id, wired into all stale-session_key consumers
(_find_live_session_by_key, _session_live_item, _live_session_payload) —
fixes the whole lookup class.
Co-authored-by: kshitijk4poor <82637225+kshitijk4poor@users.noreply.github.com>
