prisma-risk / tsoracle / 26350123394

95%

Build Type

push

github

Committed by web-flow

Commit Message

fix(client): seat leader hints atomically under the monotone-forward check (#240) (#274)

The decision to honor a NOT_LEADER hint and the cache write were two
separate lock acquisitions: `classify_not_leader_hint` checked the
monotone-forward rule via `accept_hint`, released the lock, and the
dispatch loop later wrote via `set_leader_with`. A concurrent
`record_success(higher_epoch)` landing between them could be overwritten
by the lower-epoch hint, briefly moving the cache backward during a
leadership transition. The monotone-forward guarantee held per-operation
but not across the gate-then-write pair.

Replace the pair with a single `compare_and_set_leader(endpoint, epoch)`
that re-checks the rule and writes under one lock acquisition, returning
whether the write happened. The rule itself is unchanged: reject only
when the cache is fresh, both epochs are known, and the hint's epoch is
strictly below the cached one; absent/expired entries and unknown epochs
still accept. `classify_not_leader_hint` calls it directly (its return
value still selects LeaderHint vs StaleLeaderHint), and the redundant
write in the dispatch loop is removed.

`accept_hint` and `set_leader_with` had no remaining production callers
and would have tripped the dead-code lint, so both are removed and their
tests migrated onto `compare_and_set_leader`.

Coverage Stats

52 of 52 new or added lines in 2 files covered. (100.0%)

2 existing lines in 1 file now uncovered.

10503 of 11088 relevant lines covered (94.72%)

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