---
id: "bug-1626"
status: "fixed"
status_updated: "2026-09-27"
status_note: "0c1bac44"
component: "controller"
severity: "unknown"
timestamp: "2026-08-23T05:20:00Z"
last_seen: "2026-09-19T09:00:00Z"
occurrences: 1
files: ["src/controller/job.c"]
tags: ["controller", "concurrency", "locking", "rwlock", "RTTI_LOCK_WRITE", "job-state-mutation", "race-condition", "pre-existing"]
related: []
fix_commits: ["0c1bac44"]
legacy: true
---

# bug-1626: None yet observed at runtime -- found via code trace during /kiro-validate-design review of…

## Description
None yet observed at runtime -- found via code trace during /kiro-validate-design review of scheduler-dispatch-commit.

## Environment
_Not recorded (migrated from buglog.json)._

## Reproduction
_Not recorded (migrated from buglog.json)._

## Root cause
apply_job_fail_transition() (job.c:1804-1836) is explicitly documented as safe to call only "as long as the caller already holds job under RTTI_LOCK_WRITE" (a genuine rwlock, my_rwlock_wlock(), confirmed via src/lib/jobj.c:708-725's job_lock()). Its existing caller mark_job_fail() (job.c:1844) is itself called from job_ctrl() (job.c:965) at line 1083 -- but job_ctrl()'s only lock on the job object across its entire body (traced lines 965-1090) is lock(j, RTTI_LOCK_READ) at line 999, released via unlock(j) at line 1016, well before the mark_job_fail() call at line 1083. No RTTI_LOCK_WRITE is ever taken in this path. Separately, dispatch_a_job_() (job.c:831-963) mutates j->job.allocs under only RTTI_LOCK_READ on the containing maps (c->jobmgr, c->workermgr) and RTTI_LOCK_READ on the worker w -- never RTTI_LOCK_WRITE on the job j itself. RTTI_LOCK_READ is a genuine reader lock (my_rwlock_rlock()) that does not exclude concurrent readers from each independently mutating the same object, so if two threads process job-mutating requests for the same job concurrently, this is a real data race, not just an inaccurate comment. Contrast: many OTHER call sites in the same file (e.g. job.c:768, 1687, 1795, 2058, 2089, 2127, 2169, 2206, 2293, 2340, 2416) DO correctly take RTTI_LOCK_WRITE before mutating job state, confirming RTTI_LOCK_WRITE is this codebase's established, intentional convention for job-state mutation -- the job_ctrl()/mark_job_fail() and dispatch_a_job_() call sites appear to be inconsistent outliers, not a different intentional design.

## Fix
NOT YET FIXED -- discovered as a pre-existing gap while validating scheduler-dispatch-commit's design (that spec plans to add new mutations, including a WAL-fact-durable one, to dispatch_a_job_(), and reuse mark_job_fail() for its terminal dispatch-failure path -- both inherit this open question). Needs its own investigation: either (a) confirm some other serialization guarantee (e.g. single-threaded-per-job request processing) makes RTTI_LOCK_READ sufficient in practice and the RTTI_LOCK_WRITE comments/convention are overcautious, or (b) these call sites are missing a genuine lock upgrade and should take RTTI_LOCK_WRITE like their sibling call sites do. Flagged back to scheduler-dispatch-commit's design review as Critical Issue 1 rather than fixed inline, since it is a pre-existing condition this feature would otherwise silently inherit/extend, not something this feature caused.

## Verification
_Not recorded (migrated from buglog.json)._

## References
_Not recorded (migrated from buglog.json)._