Function __libcpp_contention_state

system/lib/libcxx/src/atomic.cpp:131–133

static hash<void const volatile*> __libcpp_contention_hasher;

static __libcpp_contention_table_entry* __libcpp_contention_state(void const volatile* p) {
  return &__libcpp_contention_table[__libcpp_contention_hasher(p) & (__libcpp_contention_table_size - 1)];
}

/* Given an atomic to track contention and an atomic to actually wait on, which may be
   the same atomic, we try to detect contention to avoid spuriously calling the platform. */