FA-1375 / Concurrency / Member archive

Acquire a distributed mutex: A request acquires a lock in another coordination namespace · case 05

The distributed lock operation is admitted even though a request acquires a lock in another coordination namespace.

Member previewVariant 5 · 3 implementations · 9 checks per implementation

Case contract

Return a Boolean admission decision for acquire a distributed mutex. The record r must satisfy all of: r['lock_available'] is None; r['waiter_turn'][0] == r['waiter_turn'][1][0]; r['owner_session'][0] < r['owner_session'][1]; r['fence_increase'][0] > r['fence_increase'][1]; r['lock_namespace'][0] == r['lock_namespace'][1]. Extra tracing fields are ignored; validation does not mutate the record.

Why this case matters

A deterministic local contract for concurrency. Each negative fixture violates exactly one invariant. No transport timing, persistence, cryptographic verification, or full protocol implementation is claimed.

One recorded failure

Sample boundary fixture

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

Boundary fixture	Actual	Expected	Outcome
A request acquires a lock in another coordination namespace	`true`	`false`	Failed

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