bpo-31530: stop crashes when iterating over a file on multiple threads #3670
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Multiple threads iterating over a file can corrupt the file's internal readahead buffer resulting in crashes. To fix this, cache buffer state thread-locally for the duration of a file_iternext call and only update the file's internal state after reading completes. No attempt is made to define or provide "reasonable" semantics for iterating over a file on multiple threads. (Non-crashing) races are still present. Duplicated, corrupt, and missing data will happen.
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I'm not sure that I like this approach. See the discussion on the issue: https://bugs.python.org/issue31530#msg302932 |
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Multiple threads iterating over a file can corrupt the file's internal readahead
buffer resulting in crashes. To fix this, cache buffer state thread-locally for
the duration of a file_iternext call and only update the file's internal state
after reading completes.
No attempt is made to define or provide "reasonable" semantics for iterating
over a file on multiple threads. (Non-crashing) races are still
present. Duplicated, corrupt, and missing data will happen.
https://bugs.python.org/issue31530