Function write 

pub fn write<T: Send + Sync + 'static>(
    lock: &Arc<RwLock<T>>,
    context: &str,
) -> Option<OwnedRwLockWriteGuard<T>>

Acquire a write lock via a non-blocking spin loop with an adaptive timeout. See read() for design rationale (#1018).

Returns None on timeout, preserving the historical default behavior.