New submission from Erlend E. Aasland <erlend.aasl...@innova.no>:
Currently, the sqlite3 DB-API 2.0 attribute 'threadsafety' is hard-coded to 1, meaning "threads may share the module, but not connections". This is not always true, since it depends on the default SQLite threaded mode, selected at compile-time with the SQLITE_THREADSAFE define. SQLite's default compile-time threaded mode is SQLITE_THREADSAFE=1, also known as "serialized threaded mode", meaning SQLite can be safely used by multiple threads with no restriction. This mode equals DB-API 2.0 threadsafety level 3: threads may share the module, connections and cursors. On macOS 11.6, the system supplied Python 3 and SQLite 3 uses SQLITE_THREADSAFE=2 (also known as "multi-thread mode"), meaning SQLite can be safely used by multiple threads provided that no single database connection is used simultaneously in two or more threads. This mode equals DB-API 2.0 threadsafety level 1: threads may share the module, but not connections. With SQLITE_THREADSAFE=0 (also known as "single-thread mode"), meaning all mutexes are disabled and SQLite is unsafe to use in more than a single thread at once. This mode equals DB-API 2.0 threadsafety level 0: threads may not share the module. Suggesting to set the 'treadsafety' dynamically at sqlite3 module load time, either via Lib/sqlite3/dbapi2.py, or in C during module init (slightly faster). See also: - https://www.python.org/dev/peps/pep-0249/ - https://sqlite.org/threadsafe.html - https://discuss.python.org/t/is-sqlite3-threadsafety-the-same-thing-as-sqlite3-threadsafe-from-the-c-library/11463/11 ---------- assignee: erlendaasland components: Extension Modules messages: 405035 nosy: erlendaasland, lemburg priority: normal severity: normal status: open title: [sqlite3] set threadsafety attribute based on default SQLite threaded mode versions: Python 3.11 _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue45613> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
