Yes. Now, many short writes look exactly as one very long write from the point of view of an enqueued write that is waiting for its turn :-) I don't quite remember how fair is SQLite scheduling, in practice.
I don’t think there is any scheduling. Each connection polls to see if the write lock is available up to the max busy timeout setting.
The connection polls at these intervals: static const u8 delays[] = { 1, 2, 5, 10, 15, 20, 25, 25, 25, 50, 50, 100 };
So, if you are using the default 5 second timeout, and you are trying to acquire a lock while an exclusive lock is held, you will wait 1 second, then 2 seconds, then 5 seconds, and timeout. I’m not sure if you timeout after 3 total seconds have elapsed, or sometimes after the 2 and sometimes after the 5.
If you have a thread running many fast queries in a loop you can deny access to another thread that needs a lock. The other thread may get lucky and poll for the lock at the exact moment in between locks from the other thread, but it might not.
