[maxmcd]

This will block threads while waiting for other threads to write. That might work great for your threading model but I usually end up putting the writer in one thread and then other threads send writes to the writer thread.

[busymom0]

I do open 2 connections:

First one for writing with flags:

    SQLITE_OPEN_CREATE | SQLITE_OPEN_READWRITE | SQLITE_OPEN_FULLMUTEX

Second one for reading with flags:

    SQLITE_OPEN_READONLY | SQLITE_OPEN_FULLMUTEX

As you can note, I have SQLITE_OPEN_FULLMUTEX on both of them. Should I only have it for the writing one?

[maxmcd]

Oh nice, yes I think your threads should be able to perform reads concurrently when the write lock is not held. Would make sure you are in WAL mode as well, since I think that will improve your concurrency.