Is it possible that keep SQLite in normal locking mode and wal journal mode without mmap?

I am using SQLite on iOS developing.

Now I need the better performance of multithread-reading-and-writing and the robust of WAL journal mode without mmap.

As I know, WAL journal mode without mmap requires EXCLUSIVE locking mode, which may prevent multithread-reading-and-writing.

So, I wonder whether it is possible that keep SQLite in normal locking mode and wal journal mode without mmap? If yes, can you tell me a general idea for implementing this. No matter it needs to modify the source code or how difficult it is.