GH-49064: [C++] Fix thread safety in DictionaryArray::dictionary() #49080
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The dictionary() method was doing lazy initialization without thread safety, causing potential race conditions when multiple threads access the same DictionaryArray instance. This could lead to memory corruption or double-free errors. Fixed by using std::call_once with std::once_flag to ensure the dictionary is initialized exactly once in a thread-safe manner. Closes apache#49064
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Member
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Oh actually I think this is a duplicate of #48905 :-). |
Author
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Thanks for catching that! You're right, this is a duplicate of #48905. Should I:
Let me know! |
Member
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I think you can close the issue as there is already one. For the PR, I am not the committer in this repo so I leave it to others 👍 |
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Rationale for this change
DictionaryArray::dictionary()does lazy initialization without thread synchronization, causing race conditions when multiple threads access the same instance concurrently.Chages
std::call_oncewithstd::once_flagfor thread-safe lazy initialization#include <mutex>