gh-128421: Avoid TSAN warnings in sys._current_frames() #131548
Merged
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This tells TSAN not to sanitize PyUnstable_InterpreterFrame_GetLine(). There's a possible data race on the access to the frame's instr_ptr if the frame is currently executing. We don't really care about the race. In theory, we could use relaxed atomics for every access to
instr_ptr
, but that would create more code churn and current compilers are overly conservative with optimizations around relaxed atomic accesses.We also don't sanitize _PyFrame_IsIncomplete() because it accesses
instr_ptr
and is called from assertions within PyFrame_GetCode().