Extract fork-safe mutex into ForkSafeMutex - #1035
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The Memory adapter and Poller each carried their own copy of the fork-detection dance: track the PID, and on first use in a forked child, unlock the inherited-but-stale mutex before locking. Unlocking a mutex held by a thread that no longer exists after fork risks ThreadError. Replace both with a shared ForkSafeMutex that atomically swaps in a fresh mutex on first use in a new process instead of unlocking a stale one. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
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The
Memoryadapter andPollereach duplicated the same fork-detection dance: track the PID and, on first use in a forked child, unlock the inherited-but-stale mutex before locking it — which risks aThreadErrorsince the mutex may be held by a thread that no longer exists after fork.This extracts a shared
Flipper::ForkSafeMutexthat atomically swaps in a fresh mutex on first use in a new process (via anAtomicReference+ compare-and-set) instead of unlocking a stale one. BothMemoryandPollernow delegate to it, andPoller#startuses the reset's return value to clear@shutdown_requestedon fork. Added specs for the mutex, the memory adapter, and the poller cover the post-fork swap and the reset race.🤖 Generated with Claude Code