FA-1390 / Concurrency / Member archive

Grant permits from a distributed semaphore: A retried grant allocates the same request twice · case 05

The semaphore grant operation is admitted even though a retried grant allocates the same request twice.

Member previewVariant 5 · 3 implementations · 9 checks per implementation

Case contract

Return a Boolean admission decision for grant permits from a distributed semaphore. The record r must satisfy all of: r['permit_capacity'][0]+r['permit_capacity'][1] <= r['permit_capacity'][2]; r['positive_request'] > 0; r['request_not_granted'][0] not in r['request_not_granted'][1]; r['weighted_fifo'][0] == r['weighted_fifo'][1][0]; r['grant_session'] in ['active']. 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 retried grant allocates the same request twice	`true`	`false`	Failed

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