bpo-40077: Convert _abc module to use PyType_FromSpec() #19202
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Replace statically allocated types with heap allocated types: use PyType_FromSpec(). Add a module state to store the _abc_data_type.. Add traverse, clear and free functions to the module.
| typedef struct { | ||
| PyObject *_abc_data_type; | ||
| } _abcmodulestate; | ||
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| /* A global counter that is incremented each time a class is | ||
| registered as a virtual subclass of anything. It forces the | ||
| negative cache to be cleared before its next use. | ||
| Note: this counter is private. Use `abc.get_cache_token()` for | ||
| external code. */ | ||
| static unsigned long long abc_invalidation_counter = 0; |
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I am not sure that the abc_invalidation_counter is okay to be shared as static from interpreter Isolation point of view.
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Should we move this into PyInterpreterState?
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It seems like it would be safe to put it in the module state. The purpose of the counter is to invalidate the module cache. Registering a class in module instance 1 should not invalidate module instance 2. What do you think?
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I agree, I 've updated the PR.
| @@ -326,7 +326,7 @@ class B: | |||
| token_old = abc_get_cache_token() | |||
| A.register(B) | |||
| token_new = abc_get_cache_token() | |||
| self.assertNotEqual(token_old, token_new) | |||
| self.assertGreater(token_new, token_old) | |||
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This test might be what we wanted exactly.
I just updated the test for more validation.
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It seems like you cannot access to the module state in abc_data_new() which prevents you to move abc_invalidation_counter into the module state :-(
I suggest to leave abc_invalidation_counter as a "static" variable, but please add a FIXME like:
/* FIXME: PEP 573: Move abc_invalidation_counter into _abcmodule_state */
It's safe to keep it as a static variable until each interpreter gets its own GIL.
Until it happens, the change should move the module closer to the goal of isolated interpreters.
Misc/NEWS.d/next/Core and Builtins/2020-03-28-14-28-46.bpo-40077.4C_xJm.rst
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Co-Authored-By: Victor Stinner <vstinner@python.org>
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@vstinner Updated! Please take a look |
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Thanks, I merged your PR. |
Replace statically allocated types with heap allocated types:
use PyType_FromSpec().
Add a module state to store the _abc_data_type..
Add traverse, clear and free functions to the module.
https://bugs.python.org/issue40077