Fix a race condition in pthreads call proxying waiting #12243
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kripken
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kripken
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Sep 17, 2020
tlively
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| // while also avoids a possible race condition, as call->operationDone | ||
| // can be set *after* we checked it but *before* we do the futex_wait. The | ||
| // futex_wait is not aware of call->operationDone which means if we wait |
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I'm confused. Isn't the whole point of futex_wait to do an atomic compare-and-block operation? Why wouldn't it be aware of call->operationDone?
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Ah, I think you're right, while this fixes the issue the diagnosis does look wrong.
This was referenced Sep 17, 2020
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I have found the actual cause here, and will open a refactoring PR and then a fix PR shortly. |
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I am not completely happy with this solution, see details in
the comment. ideas welcome!