Feature or enhancement

Proposal:

I hope this issue will complete _datetime isolation.

• Py_MOD_PER_INTERPRETER_GIL_SUPPORTED should be applied in sync with _zoninfo?

  • YES: Possible.

• Can a module state have a C-API structure, keeping a capsule just for comatibility?

  • NO: Possible, but a user should not touch the module state.

• C-API supports only the main interpreter? Otherwise, PyInterpreterState is acceptable to point each structure?

  • NO: PyDateTimeAPI cannot emit an error. Also, no PyInterpreterState member is accessible from datetime.h. UPDATE: Seems to be possible by using a global function pointer instead of a function.

Specific issue:

• Initialize/Finalize Python multiple time and import datetime each time lead to a memory corruption #118608

Links to previous discussion of this feature:

• Isolate Stdlib Extension Modules #103092
• gh-71587: Isolate _datetime #102995
• gh-71587: Establish global state in _datetime #110475

Linked PRs (closed)

• gh-117398: datetime: Support per-interpreter C-API #117399
• gh-117398: datetime: Make use of C-API capsules for sub-interpreters #117413
• gh-117398: datetime: Use wrappers for C-API functions #118115
• gh-117398: datetime: Access C-API via PyInterpreterState #118357

Linked PRs

• gh-117398: Isolate _datetime (3.13.0a6 PoC) #117498
• gh-117398: Isolate _datetime (3.13.0a6 PoC) with AC #118337
• gh-117398: Move types to datetime state #118606
• gh-117398: Add multiphase support to _datetime #119373
• gh-117398: Statically Allocate the Datetime C-API #119472
• gh-117398: Add datetime C-API type check test for subinterpreters #119604
• [3.13] gh-117398: Add multiphase support to _datetime (gh-119373) #119636
• gh-117398: Convert datetime.IsoCalendarDate To A Heap Type #119637
• [3.13] gh-117398: Revert gh-119636, Add multiphase support to _datetime #119639
• gh-117398: Add datetime Module State #119640
• [3.13] gh-117398: Statically Allocate the Datetime C-API (GH-119472) #119641
• gh-117398: gh-119655: datetime: Init static state once & don't free it #119662
• [3.13] gh-117398: Add multiphase support to _datetime #119694
• [3.13] gh-117398: Convert datetime.IsoCalendarDate To A Heap Type (gh-119637) #119695
• gh-117398: Add datetime Module State #119810
• gh-117398: Use Per-Interpreter State for the _datetime Static Types #119929
• [3.13] gh-117398: Add datetime Module State (gh-119810) #120004
• [3.13] gh-117398: Use Per-Interpreter State for the _datetime Static Types (gh-119929) #120009
• gh-71587: Drop local reference cache to _strptime module in _datetime #120224
• [3.13] gh-117398: Add datetime C-API type check test for subinterpreters (gh-119604) #120463
• gh-117398: Use the correct module loader for iOS in datetime CAPI test. #120477
• [3.13] gh-117398: Use the correct module loader for iOS in datetime CAPI test (GH-120477) #121561