Function zero_reinit_after_fork 

pub unsafe fn zero_reinit_after_fork<T>(lock: *const T)

Reset a lock to its initial (unlocked) state by zeroing its bytes.

After fork(), any lock held by a now-dead thread would remain permanently locked. We zero the raw bytes (the unlocked state for all parking_lot raw lock types) instead of using the normal unlock path, which would interact with stale waiter queues.

Safety

Must only be called from the single-threaded child process immediately after fork(), before any other thread is created. The type T must represent the unlocked state as all-zero bytes (true for parking_lot::RawMutex, RawRwLock, RawReentrantMutex, etc.).