* Example: In any thread, the first call of URCU_TLS(rcu_reader)
* is called from rcu_register_thread(), so we can ensure all later
* URCU_TLS(rcu_reader) in any thread is async-signal-safe.
* Example: In any thread, the first call of URCU_TLS(rcu_reader)
* is called from rcu_register_thread(), so we can ensure all later
* URCU_TLS(rcu_reader) in any thread is async-signal-safe.