Bug report

Bug description:

The sqlite3Blob class registers a weakref to itself on the Connection it came from. These are added to a list and never cleaned up, so if you have a long-lived connection and call.blobopen() repeatedly, you gradually accumulate ever more dead weakrefs.

It looks like the blob weakrefs were added to match a similar system for weakrefs (removed in#144378), but the code to periodically clear out dead weakrefs was missed.

importgcimportsqlite3conn=sqlite3.connect(":memory:")conn.execute("CREATE TABLE foo(a INTEGER PRIMARY KEY, b BLOB)")conn.execute("INSERT INTO foo VALUES(NULL, ?)", (b'abcdefpokpokpko',))conn.commit()# Create & destroy many Blob objectsfor_inrange(10_000):conn.blobopen("foo","b",1)# Get a reference to the internal list of blob weakrefs - you may need to play with the index hereblob_list=gc.get_referents(conn)[-3]print(len(blob_list))

CPython versions tested on:

3.14

Operating systems tested on:

Linux

Linked PRs

• gh-144424: Clean up dead weakrefs to sqlite3 Blob objects #144435