gh-112075: _Py_dict_lookup needs to lock shared keys - #117528
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colesbury
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This looks right, but I'm still seeing issues with the test that uncovered the problem. I'll investigate more today.
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colesbury
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I'm still looking at _Py_dict_lookup, but I think insertdict and dict_setdefault_ref_lock_held can be simpler if they handle split dictionaries early on and separate from the main code path.
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…sertdict and setdefault
colesbury
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LGTM other than the unused code warning in the default build
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| unicodekeys_lookup_unicode_threadsafe(PyDictKeysObject* dk, PyObject *key, |
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Unused code warning
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_Py_dict_lookup needs to lock the shared keys if we have a split dictionary. If we're looking up with a non-exact unicode we need to also incref the keys as the lookup could mutate the keys and we could lose the last reference.
insertdict is updated to avoid contention on the shared dict lookup by calling the threadsafe unicode lookup directly and only falling back to _Py_dict_lookup if the thread safe lookup can't succeed.