[3.14] gh-144295: Fix data race in dict method lookup and global load (gh-144312) #144346
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…l load (pythongh-144312) In `_PyDict_GetMethodStackRef`, only use the fast-path unicode lookup when the dict is owned by the current thread or already marked as shared. This prevents a race between the lookup and concurrent dict resizes, which may free the PyDictKeysObject (i.e., it ensures that the resize uses QSBR). Address a similar issue in `_Py_dict_lookup_threadsafe_stackref` by calling `ensure_shared_on_read()`. (cherry picked from commit e666a01) Co-authored-by: Sam Gross <colesbury@gmail.com>
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In
_Py_dict_lookup_threadsafe_stackref, callensure_shared_on_read()toprevent a race between the lookup and concurrent dict resizes, which may free
the PyDictKeysObject (i.e., it ensures that the resize uses QSBR).
(cherry picked from commit e666a01)
new_keys_objectindictobject.c#144295