Every managed connection now goes through configure_connection: WAL,
foreign keys, the 30 s busy timeout and, when WAL is active,
synchronous=NORMAL. Under FULL each commit flushed to disk while it held
SQLite's only write lock; on slow Windows disks a burst of writers (a
scan beside ComfyUI saves, or the concurrency tests) starved a polling
waiter past the busy timeout and it failed with 'database is locked'.
With a 60 ms emulated flush on Linux, 8 threads x 50 save+use calls went
from 49.6 s with a 32.1 s worst call (and 'database is locked' in the
unit test) to 0.7 s with a 0.4 s worst call. NORMAL in WAL mode keeps the
database consistent after an application crash; only an OS crash or
power loss can drop the most recent commits. In-memory or non-WAL
databases keep SQLite's FULL default.
Vito Sansevero
ba4e958804