shared_mutex: Fix races around st_.store()#41
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avdgrinten merged 1 commit intomanagarm:masterfrom Feb 21, 2026
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The implementation of async::shared_mutex previously did atomic store()s to the state even in situations where the shared lock count can be changed concurrently. This led to a race condition. * In shared_lock(), we can simply drop the problematic store() since it only writes back the state that we are currently in anyway. * In shared_unlock(), we need a CAS loop to avoid this issue.
qookei
approved these changes
Feb 20, 2026
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The implementation of
async::shared_mutexpreviously did atomicstore()s to the state even in situations where the shared lock count can be changed concurrently. This led to a race condition.lock_shared(), we can simply drop the problematicstore()since it only writes back the state that we are currently in anyway.unlock_shared(), we need a CAS loop to avoid this issue.