Quoting [https://sqlite.org/threadsafe.html](https://sqlite.org/threadsafe.html):
_"The sqlite3_threadsafe() interface predates the multi-thread mode and start-time and run-time mode
selection and so is unable to distinguish between multi-thread and serialized mode [...]"_
This is not correct. `sqlite3_threadsafe()` is implemented as follows:
```
int sqlite3_threadsafe(void){ return SQLITE_THREADSAFE; }
```
(The [sqlite3_threadsafe() C API](https://sqlite.org/c3ref/threadsafe.html) docs seems fine, though.)