FA-41577 / Listener lifecycle / Member archive

Finalization accidentally permits a strong-owner resurrection · case 02

Finalization accidentally permits a strong-owner resurrection; the returned lifecycle plan violates the stated transition contract.

Member previewVariant 2 · 3 implementations · 8 checks per implementation

Case contract

Resolve a weakly owned observer target at dispatch time. A dead or finalized target is skipped, its registration becomes a tombstone, and a live target is pinned only for the callback. Sweep only tombstones outside dispatch. A strong-owner override prevents collection but does not revive a finalized target. Dead callback contexts are also excluded. A weak method binding resolves its exact method name or becomes absent; a different extant fallback method is never invoked. Inputs are finite state snapshots, including transitional and stale states; output fields are the exact independent actions/metadata defined by the corrected expression table. Numeric fixture capacities and counts vary with N. Field definitions, each independently computed from the input snapshot: invoke = s['registered'] and (s['alive'] or s['strong']) and not s['finalized'] and s['context_alive'] and s['callback']; pin = s['dispatching'] and (s['alive'] or s['strong']) and not s['finalized']; tombstone = s['tombstone'] or s['finalized'] or (not s['alive'] and not s['strong']); sweep = s['sweep'] and s['tombstone'] and not s['dispatching']; context = not s['context_alive']; pins = max(0,s['pins']-int(s['dispatching'])); retain = s['strong'] and not s['finalized']; resurrect = False; orphan = s['method'] if s['method'] in s['methods'] else None; defer = s['sweep'] and s['tombstone'] and s['dispatching']

Why this case matters

Observer implementations need to preserve this state while subscriptions enter, execute, and leave their lifecycle.

One recorded failure

Sample boundary fixture

This sample comes from the broken implementation of a controlled reproducer.

Boundary fixture	Actual	Expected	Outcome
transition 0	`{"context": true, "defer": true, "invoke": false, "orphan": null, "pin": false, "pins": 3, "resurrect": true, "retain": false, "sweep": false, "tombstone": true}`	`{"context": true, "defer": true, "invoke": false, "orphan": null, "pin": false, "pins": 3, "resurrect": false, "retain": false, "sweep": false, "tombstone": true}`	Failed

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