gh-135607: remove null checking of weakref list in dealloc of extension modules and objects (#135614)
(cherry picked from commit b1056c2a44)
Co-authored-by: Xuanteng Huang <44627253+xuantengh@users.noreply.github.com>
Co-authored-by: Kumar Aditya <kumaraditya@python.org>
Add a helper for raising DB-API compatible exceptions based on the
result code of SQLite C APIs. Some APIs do not store the error indicator
on the database pointer, so we need to be able to deduce the DB-API
compatible exception directly from the error code.
- rename _pysqlite_seterror() as set_error_from_db()
- introduce set_error_from_code()
Most mutable data is protected by a striped lock that is keyed on the
referenced object's address. The weakref's hash is protected using the
weakref's per-object lock.
Note that this only affects free-threaded builds. Apart from some minor
refactoring, the added code is all either gated by `ifdef`s or is a no-op
(e.g. `Py_BEGIN_CRITICAL_SECTION`).
* Replace PyWeakref_GET_OBJECT() with _PyWeakref_GET_REF().
* _sqlite/blob.c now holds a strong reference to the blob object
while calling close_blob().
* _xidregistry_find_type() now holds a strong reference to registered
while using it.
