LifetimeManager: guard s_OnTimeout against unmatched timer fires#40449
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LifetimeManager: guard s_OnTimeout against unmatched timer fires#40449
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Pull request overview
This PR fixes a race in LifetimeManager::s_OnTimeout where an unmatched timer fire could cause m_lastTimerWait to be overwritten with nullptr, breaking the destructor’s “wait for pending callbacks” guarantee in the WSL Windows service lifetime tracking.
Changes:
- Guarded the timer
release()/reset()/swap()sequence so it only runs when the timed-out callback entry was actually found (i.e.,clientLocal.timeris non-null). - Added an explanatory comment documenting why the guard is needed.
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When the timer callback runs but find_if doesn't match (because the entry was already removed and recreated by RefreshClientCallback or similar), clientLocal stays default-constructed with a null timer. The unconditional .release()/.swap() then clobbers any previously stashed m_lastTimerWait with null, breaking the destructor's wait guarantee. Skip the swap when there is no timer to stash. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
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If the timer fires but
find_ifdoesn't match (entry erased, or replaced by the retry path),clientLocalis default-constructed and the unconditional swap clobbersm_lastTimerWaitwith null - breaking the destructor's wait-for-pending-callbacks guarantee.Guard the swap so an unmatched fire is a no-op.