[issue38891] ShareableList read and write access is O(N), should be O(1)

Dirk Roorda added the comment: I can see that the performance of ShareableList is much better now. Still the performance of list operations on a ShareableList may be degraded by a factor 200-300 with respect to a normal list. If this is unavoidable then the docs should clearly mention this de

[issue38891] ShareableList read and write access is O(N), should be O(1)

Change by Antoine Pitrou : -- resolution: -> fixed stage: patch review -> resolved status: open -> closed ___ Python tracker ___ __

[issue38891] ShareableList read and write access is O(N), should be O(1)

Antoine Pitrou added the comment: New changeset c8f1715283ec51822fb37a702bf253cbac1af276 by Thomas Krennwallner in branch 'master': bpo-38891: avoid quadratic item access performance of ShareableList (GH-18996) https://github.com/python/cpython/commit/c8f1715283ec51822fb37a702bf253cbac1af276

[issue38891] ShareableList read and write access is O(N), should be O(1)

Change by Antoine Pitrou : -- versions: +Python 3.9 -Python 3.8 ___ Python tracker ___ ___ Python-bugs-list mailing list Unsubscribe

[issue38891] ShareableList read and write access is O(N), should be O(1)

Change by Thomas Krennwallner : -- keywords: +patch nosy: +tkren nosy_count: 3.0 -> 4.0 pull_requests: +18343 stage: -> patch review pull_request: https://github.com/python/cpython/pull/18996 ___ Python tracker

[issue38891] ShareableList read and write access is O(N), should be O(1)

Dong-hee Na added the comment: IMHO, 1. replace self._allocated_bytes to self._sum_allocated_bytes 2. initialize self._sum_allocated_bytes at the __init__ time. 2. if self._allocated_bytes is needed, calculate from _sum_allocated_bytes it will take O(1) If the suggestion is accepted, I'd lik

[issue38891] ShareableList read and write access is O(N), should be O(1)

New submission from Jake Northey : For an illustration of the performance implications of the __getitem__ and __setitem__ implementation, see the article below. https://medium.com/@rvprasad/performance-of-system-v-style-shared-memory-support-in-python-3-8-d7a7d1b1fb96 The issue appears to be d