Will this have support for macOS by inserting itself, as jemalloc does, as the default malloc zone? If so, does that mean it will be very fast at determining if a given pointer was allocated by libpas?
libpas can already determine if it owns a pointer in O(1) time and no locking. It uses megapages for this purpose. Though, right now, it's not configured to fully leverage this (if you pass an unknown ptr to free then as a last step it'll lock the heap_lock even though it would be a small change to just use megapages there).