I think it's a problem because they snapshot the filter to avoid the atomic overhead, so you'd be writing to a stale copy, that will never be read. You could ju

I think it's a problem because they snapshot the filter to avoid the atomic overhead, so you'd be writing to a stale copy, that will never be read. You could just keep the last 2 filters atomic instead, and skip the RWlock that way. Profiling might tell you which approach is better.