fi_fetch_atomic_valid(3) on Linux
The text a68c2ce2cbd9, as Debian 10 (Buster) shipped it.
Remote atomic functions fi_atomic / fi_atomicv / fi_atomicmsg / fi_inject_atomic : Initiates an atomic operation to remote memory fi_fetch_atomic / fi_fetch_atomicv / fi_fetch_atomicmsg : Initiates an atomic operation to remote memory, retrieving the initial value. fi_compare_atomic / fi_compare_atomicv / fi_compare_atomicmsg : Initiates an atomic compare-operation to remote memory, retrieving the initial value. fi_atomicvalid / fi_fetch_atomicvalid / fi_compare_atomicvalid / fi_query_atomic : Indicates if a provider supports a specific atomic operation