fix: remove panic on missing rangeLastWaitKey in lock conflict handler#24051
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mergify[bot] merged 4 commits intomatrixorigin:mainfrom Apr 6, 2026
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The panic "BUG: missing range last wait key" can be triggered by a legitimate race condition: 1. txn3 acquires range lock [k1,k4], conflicts with txn1 at k4 2. txn3 waiter is added to k4, rangeLastWaitKey set to k4 3. txn3 blocks in wait() — releases l.mu 4. txn1 unlocks k4: closeTxn() notifies txn3 waiter, isEmpty() returns true, k4 is deleted from store 5. txn3 wakes, retries, conflicts at k2 6. handleLockConflictLocked tries to clean up old k4 waiter 7. k4 no longer exists → panic Between step 3 (waiter blocks without lock) and step 6 (conflict retry), another transaction can legitimately delete the lock entry. The next line already guards with `if ok &&`, so removing the panic is safe — the waiter was already cleaned up by the unlock path. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Review Summary by QodoRemove panic on missing rangeLastWaitKey in lock conflict handler
WalkthroughsDescription• Remove panic on missing rangeLastWaitKey in lock conflict handler • Panic triggered by legitimate race condition during concurrent transactions • Existing guard clause already handles missing lock entry safely Diagramflowchart LR
A["Transaction conflict retry"] -->|rangeLastWaitKey lookup| B["Lock entry deleted by unlock"]
B -->|Previously panicked| C["Removed panic"]
C -->|Existing guard handles| D["Safe cleanup path"]
File Changes1. pkg/lockservice/lock_table_local.go
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Code Review by Qodo🐞 Bugs (0) 📘 Rule violations (0) 📎 Requirement gaps (0)
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What type of PR is this?
Which issue(s) this PR fixes:
issue #24030
What this PR does / why we need it:
The panic "BUG: missing range last wait key" can be triggered by a legitimate race condition:
Between step 3 (waiter blocks without lock) and step 6 (conflict retry), another transaction can legitimately delete the lock entry. The next line already guards with
if ok &&, so removing the panic is safe — the waiter was already cleaned up by the unlock path.