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[mypyc] Make list.pop() atomic on free-threaded builds - #22215
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Fix mypyc/mypyc#1196. Remove the item directly while holding the list's critical section, using the same steps as `del a[i]` in CPython, instead of getting and deleting the item in separate operations. This avoids an extra incref/decref pair and a nested critical section, so pop() is also faster than the previous non-atomic implementation (15-37% in microbenchmarks).
p-sawicki
approved these changes
Oct 16, 2026
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Fix mypyc/mypyc#1196.
Remove the item directly while holding the list's critical section, using the same steps as
del a[i]in CPython, instead of getting and deleting the item in separate operations. This avoids an extra incref/decref pair and a nested critical section, so pop() is also faster than the previous non-atomic implementation (15-37% in microbenchmarks).