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fix(source): armWatchdog self-join guard no longer races the thread assignment (0.34.1) - #200
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…ssignment (0.34.1) The guard read state_.watchdog on the watchdog thread inside on_expire while the body thread was still move-assigning that member; the start semaphore orders only the other direction. Key the guard on a thread_local flag set by the watchdog thread before it runs on_expire. Reported by ThreadSanitizer via ProviderJobTest.RearmingTheWatchdogFromOnExpireIsANoOp. Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
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Why
PJ4's widened ThreadSanitizer lane (PlotJuggler/PJ4#649) now runs the SDK's own tests and reports a data race in
ProviderJobTest.RearmingTheWatchdogFromOnExpireIsANoOp:state_.watchdog = std::thread(...)inJobControl::armWatchdog.state_.watchdog.joinable() && state_.watchdog.get_id() == this_thread::get_id(), reached whenon_expirere-arms.The
startedsemaphore orders the watchdog's release before the body's acquire, not the body's assignment before the watchdog's later read, so nothing publishes the write. Benign in practice (the read happens ≥timeoutlater) but a genuine race.Fix
The guard keys on a
thread_localflag the watchdog thread sets before runningon_expire, instead of reading the thread object. Behaviour is unchanged: re-arming from insideon_expirestays a no-op.Version
PATCH → 0.34.1 (consumer-visible bug fix, no ABI/API change). PJ4 will bump its pin and drop the temporary
race:PJ::sdk::source::JobControl::armWatchdogsuppression it carries meanwhile.🤖 Generated with Claude Code